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Queyrel É, Lanaret M, Khalil T, Al Gahatany M, Chaix R, Lemaire JJ, Moisset X, Chassin V, Brun L, Dedieu V, Biau J. [Frameless trigeminal neuralgia radiosurgery with a dedicated linear accelerator: From equipment commissioning to initial clinical results]. Cancer Radiother 2024; 28:164-173. [PMID: 38490925 DOI: 10.1016/j.canrad.2023.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/07/2023] [Accepted: 07/18/2023] [Indexed: 03/17/2024]
Abstract
PURPOSE Radiosurgery for the treatment of trigeminal neuralgia delivers a very high dose in a single fraction, over a few millimeters, at a single isocenter placed along the nerve. We present here the different steps that have been performed to validate small beams by conical collimators, and report the clinical results of the first patients treated on Novalis Tx®, frameless. MATERIAL AND METHODS First, the geometric accuracy of 4 and 6mm conical collimators was evaluated using Winston-Lutz tests; then dosimetric data acquisition was performed using high spatial resolution detectors (PTW 60019 microdiamond and a PTW 60017 E-diode). The corrective factors of the TRS 483 report were applied to calculate the collimator aperture factors. These dosimetric data were then compared with the data implemented in the iPlan® treatment planning system. Then end-to-end tests were performed to control the entire treatment process using an anthropomorphic phantom "STEEV". Between 2020 and 2022, 18 patients were treated for refractory trigeminal neuralgia on Novalis Tx®, frameless, with Exactrac® repositioning. A total of 17 patients were evaluated (one was lost to follow-up) using the BNI score for pain assessment and MRI with a median follow-up of 12 months. RESULTS The quality criteria of geometric and dosimetric accuracy were met for the 6-mm cone but not for the 4-mm cone. All patients were treated with a 6-mm cone with a dose of 90Gy prescribed at the isocenter at the root entry zone. Initial pain control was obtained in 70.5% of our patients, and 53% maintained pain control with a median follow-up of 12 months. All recurrences occurred within 3 to 6 months after radiosurgery. No brainstem toxicity was observed. Six patients had non-disabling facial hypoesthesia, half of whom already had pretreatment hypoesthesia. CONCLUSION The treatment of trigeminal neuralgia on a dedicated linear accelerator is a highly technical treatment whose accuracy and safety are paramount. The physical measurements allowed the commissioning of the technique with a 6mm cone. Our first clinical results are in accordance with the literature.
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Affiliation(s)
- É Queyrel
- Département de radiothérapie, centre Jean-Perrin, 58, rue Montalembert, 63011 Clermont-Ferrand cedex 1, France
| | - M Lanaret
- Département de physique médicale, centre Jean-Perrin, Clermont-Ferrand, France
| | - T Khalil
- Service de neurochirurgie, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - M Al Gahatany
- Service de neurochirurgie, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - R Chaix
- Service de neurochirurgie, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - J-J Lemaire
- Service de neurochirurgie, CHU de Clermont-Ferrand, Clermont-Ferrand, France; Institut Pascal, CNRS, Clermont-Auvergne INP, université Clermont-Auvergne, Clermont-Ferrand, France; Inserm U1240 IMoST, université Clermont-Auvergne, Clermont-Ferrand, France
| | - X Moisset
- Service de neurologie, Neuro-Dol, CHU de Clermont-Ferrand, université Clermont-Auvergne, Inserm U1107, Clermont-Ferrand, France
| | - V Chassin
- Département de physique médicale, centre Jean-Perrin, Clermont-Ferrand, France
| | - L Brun
- Département de radiothérapie, centre Jean-Perrin, 58, rue Montalembert, 63011 Clermont-Ferrand cedex 1, France
| | - V Dedieu
- Département de physique médicale, centre Jean-Perrin, Clermont-Ferrand, France; Institut Pascal, CNRS, Clermont-Auvergne INP, université Clermont-Auvergne, Clermont-Ferrand, France; Inserm U1240 IMoST, université Clermont-Auvergne, Clermont-Ferrand, France
| | - J Biau
- Département de radiothérapie, centre Jean-Perrin, 58, rue Montalembert, 63011 Clermont-Ferrand cedex 1, France; Institut Pascal, CNRS, Clermont-Auvergne INP, université Clermont-Auvergne, Clermont-Ferrand, France; Inserm U1240 IMoST, université Clermont-Auvergne, Clermont-Ferrand, France.
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Koide Y, Aoyama T, Tanaka H, Shindo Y, Nagai N, Kitagawa T, Shimizu H, Hashimoto S, Tachibana H, Kodaira T. Changing trends in gamma knife surgery to linear accelerator brain stereotactic radiotherapy in Japan: a survey based on the nationwide claims database. Jpn J Radiol 2024; 42:415-423. [PMID: 37979018 PMCID: PMC10980651 DOI: 10.1007/s11604-023-01511-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 10/26/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE This study evaluated the trends in the platform for stereotactic radiotherapy to the brain (SRT), utilizing the open data of the National Database published by the Ministry of Health, Labour, and Welfare. MATERIALS AND METHODS This study analyzed data from FY2014 to FY2021. The practices included in the study were gamma knife surgery (GKS) and SRT with a linear accelerator (LINAC). The total number of outpatient and inpatient cases in each SRT system was evaluated annually. RESULTS From April 2014 to March 2022, the study included 212,016 cases (102,691 GKS and 109,325 LINAC) of the registered 1,996,540 radiotherapy cases. In the first year, 13,117 (54.1%) cases were GKS, and 11,128 (45.9%) were LINAC; after that, GKS decreased, and LINAC increased, reaching the same rate in FY2017. Compared to the first year, the final year showed 11,702 GKS (- 1415 or - 10.8%) and 17,169 LINAC (+ 6041 or + 54.3%), with an increase of 4626 total SRT cases to 28,871 (+ 19.1%). The percentage of outpatient treatment also increased from 4.6 to 11.8% for GKS and from 44.7 to 57.9% for LINAC. CONCLUSION The study found a gradual decrease in the selection of GKS, an increasing trend in the selection of LINAC, and an increase in the overall number of stereotactic irradiations. In particular, the proportion of outpatient treatment increased, indicating that more than half of LINAC was selected for outpatient treatment.
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Affiliation(s)
- Yutaro Koide
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan.
| | - Takahiro Aoyama
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
| | - Hiroshi Tanaka
- Department of Radiation Oncology, Shiokawa Hospital Gamma Knife Center, Suzuka, Japan
| | - Yurika Shindo
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
| | - Naoya Nagai
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
| | - Tomoki Kitagawa
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
| | - Shingo Hashimoto
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
| | - Hiroyuki Tachibana
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
| | - Takeshi Kodaira
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, Aichi, Japan
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Araujo AS, Silva RMV, Souza DN. Evaluation of conventional IMRT and VMAT strategies for postmastectomy radiation therapy after immediate implant-based reconstruction using the new ESTRO-ACROP contouring guidelines. Radiat Environ Biophys 2024; 63:59-70. [PMID: 38300284 DOI: 10.1007/s00411-024-01059-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 01/03/2024] [Indexed: 02/02/2024]
Abstract
This study evaluated the usability of conventional templates based on the new contour guidelines of the European Society of Radiation and Oncology and Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) for treatment plans of postmastectomy radiotherapy after immediate implant-based reconstruction. Intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans generated with two different treatment planning systems (TPSs, Eclipse and Monaco) were examined. Six computed tomography scans of patients aged 35-54 years were retrospectively analysed who had undergone mastectomy and breast reconstruction using silicone implants after being diagnosed with left breast cancer. Six radiation oncologists participated in this study, and each of them contoured the target volume of one left breast using conventional contour (CTV-CONV) and new contour (CTV-ESTRO) methods. This study showed that compared with CTV-CONV, using CTV-ESTRO with objectives and cost functions similar to those of TPSs worsened the target volume coverage and increased the total number of monitor units. Considering the organs at risk, CTV-ESTRO tended to increase the mean dose delivered to the contralateral lung. It is concluded that the approach used for the new ESTRO-ACROP contour method cannot be applied in a manner similar to that for the conventional breast contour method, implying that the new ESTRO-ACROP contour method may require more time for improving plans for a given treatment.
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Affiliation(s)
- Andreyson S Araujo
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, 49100-000, Brazil
| | | | - Divanizia N Souza
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, 49100-000, Brazil.
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Rodriguez M, Sempau J, Brualla L. Monte Carlo simulation of the Varian TrueBeam flattened-filtered beams using a surrogate geometry in PRIMO. Radiat Oncol 2024; 19:14. [PMID: 38267999 PMCID: PMC10809682 DOI: 10.1186/s13014-024-02405-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 01/15/2024] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND Monte Carlo simulation of radiation transport for medical linear accelerators (linacs) requires accurate knowledge of the geometrical description of the linac head. Since the geometry of Varian TrueBeam machines has not been disclosed, the manufacturer distributes phase-space files of the linac patient-independent part to allow researchers to compute absorbed dose distributions using the Monte Carlo method. This approach limits the possibility of achieving an arbitrarily small statistical uncertainty. This work investigates the use of the geometry of the Varian Clinac 2100, which is included in the Monte Carlo system PRIMO, as a surrogate. METHODS Energy, radial and angular distributions extracted from the TrueBeam phase space files published by the manufacturer and from phase spaces tallied with PRIMO for the Clinac 2100 were compared for the 6, 8, 10 and 15 MV flattened-filtered beams. Dose distributions in water computed for the two sets of PSFs were compared with the Varian Representative Beam Data (RBD) for square fields with sides ranging from 3 to 30 cm. Output factors were calculated for square fields with sides ranging from 2 to 40 cm. RESULTS Excellent agreement with the RBD was obtained for the simulations that employed the phase spaces distributed by Varian as well as for those that used the surrogate geometry, reaching in both cases Gamma ([Formula: see text], 2 mm) pass rates larger than [Formula: see text], except for the 15 MV surrogate. This result supports previous investigations that suggest a change in the material composition of the TrueBeam 15 MV flattening filter. In order to get the said agreement, PRIMO simulations were run using enlarged transport parameters to compensate the discrepancies between the actual and surrogate geometries. CONCLUSIONS This work sustains the claim that the simulation of the 6, 8 and 10 MV flattening-filtered beams of the TrueBeam linac can be performed using the Clinac 2100 model of PRIMO without significant loss of accuracy.
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Affiliation(s)
- Miguel Rodriguez
- Hospital Paitilla, Calle 53 y ave Balboa, Panamá, Panama
- Instituto de Investigaciones Científicas y Servicios de Alta Tecnología-AIP (INDICASAT-AIP), Ciudad del Saber, Edificio 219, Panamá, Panama
| | - Josep Sempau
- Department of Physics, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona, Spain
- Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya, Diagonal 647, 08028, Barcelona, Spain
- Centros de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Diagonal 647, 28029, Madrid, Spain
| | - Lorenzo Brualla
- Westdeutsches Protonentherapiezentrum Essen (WPE), Hufelandstraße 55, 45147, Essen, Germany.
- West German Cancer Center (WTZ), Hufelandstraße 55, 45147, Essen, Germany.
- Medizinische Fakultät, Universität Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany.
- German Cancer Consortium DKTK, Hufelandstraße 55, 45147, Essen, Germany.
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Spaniol M, Abo-Madyan Y, Ruder AM, Fleckenstein J, Giordano FA, Stieler F. Homogenous dose prescription in Gamma Knife Radiotherapy: Combining the best of both worlds. Phys Med 2024; 117:103202. [PMID: 38159546 DOI: 10.1016/j.ejmp.2023.103202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/28/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024] Open
Abstract
PURPOSE Stereotactic radiosurgery with linear accelerators (LINACs) or Leksell Gamma Knife® (LGK, Elekta AB) is an established treatment option for intracranial tumors. When those are involving/abutting organs at risk (OAR), homogenous and normofractionated treatments outmatch single fraction deliveries. In such situations, it would be desirable to balance LINAC's homogeneity benefits with LGK's dose gradient attributes. In this study, we determined homogeneity and OAR sparing ranges using a non-clinical, homogenous prototype version of LGK Lightning. METHODS We retrospectively analyzed thirty fractionated LGK Icon in-house patients with acoustic neuromas, pituitary adenomas and meningiomas. Four treatment plans were generated (54 Gy,1.8 Gy/fx) per patient: one LINAC plan, one clinical Lightning plan ("LGK") and two prototype Lightning plans ("LGK Hom" and "LGK OAR"). We analyzed Dmean and D2% for different OAR, Gradient Index (GI), Paddick Conformity Index (PCI), Homogeneity Index (HI) and beam-on-time (BOT). RESULTS While the LINAC vs. Lightning plans (LGK Hom|LGK OAR|LGK) boast better homogeneity (median: 1.08 vs. 1.18|1.24|1.35) and shorter BOT (median: 137 s vs. 432 s|510 s|510 s), Lightning plans show improved GI (median: 6.68 vs. 3.86|3.50|3.19), similar PCI (median: 0.75 vs. 0.76|0.75|0.82) and significantly reduced OAR doses. For in-tumor OAR, LGK Hom and LINAC plans achieves similar OAR sparing with improved GI for LGK Hom. CONCLUSIONS This study is a preliminary attempt to combine the dosimetric advantages of LINAC and LGK treatment planning. We observed that LGK plan homogeneity can be improved toward LINAC standards while maintaining the LGK advantage of favorable OAR doses and GI. Additionally, in-tumor OAR hotspots can be considerably reduced.
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Affiliation(s)
- Manon Spaniol
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
| | - Yasser Abo-Madyan
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
| | - Arne M Ruder
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
| | - Jens Fleckenstein
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
| | - Frank A Giordano
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
| | - Florian Stieler
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
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Ratheesh KE, Mayakannan K. Angular dependence of the TL and OSL dosimeters in the clinical 6 MV photon Beam. Appl Radiat Isot 2023; 202:111073. [PMID: 37890243 DOI: 10.1016/j.apradiso.2023.111073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 10/05/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023]
Abstract
The angular response of luminescent dosimeters (LD), in particular TLD and OSLD, has been compared by applying 6 MV X-ray photons from Versa HD clinical linear accelerator. The study admitted for the irradiation of TLD (n = 475) and OSLD (n = 475) under phantom set up in various gantry angles from 00 to ±900 and various field sizes from 10 x 10 cm2 to 30 x 30 cm2. The variance in the output was observed between 4.4% for TLD and 3.9% for OSLD. A significant deviation from the desired output was detected, towards the angle of incidents, at ±800 to ±900. Additionally, there is no evidence of variation in the dose measurement due to the difference in field size. These results demonstrate a good approximation to the vendor-specified tolerance limits, justifying the use of these LDs within angular incidents of radiation up to ±700. The TLD and OSLD better dose-response is achieved to a gantry angle up to ±700 from the perpendicular incidents. The result shows that both TLD and OSLD could be used as dosimeters for a treatment field that does not extend beyond ±700 beam angle.
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Affiliation(s)
- K E Ratheesh
- D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India
| | - Krishnan Mayakannan
- D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India.
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Wang CY, Ho LT, Lin LY, Chan HM, Chen HY, Yu TL, Huang YS, Kuo SH, Lee WJ, Chen JLY. Noninvasive cardiac radioablation for ventricular tachycardia: dosimetric comparison between linear accelerator- and robotic CyberKnife-based radiosurgery systems. Radiat Oncol 2023; 18:187. [PMID: 37950307 PMCID: PMC10638803 DOI: 10.1186/s13014-023-02370-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 10/29/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Few dosimetric comparisons have been published between linear accelerator (LA)-based systems and CyberKnife (CK)-based robotic radiosurgery systems for cardiac radio-ablation in ventricular tachycardia. This study aimed to compare the dosimetry of noninvasive cardiac radio-ablation deliverable on LA with that on CK. METHODS Thirteen patients who underwent noninvasive cardiac radio-ablation by LA were included. The prescribed dose was 25 Gy in 1 fraction, and the average planning target volume was 49.8 ± 31.0 cm3 (range, 14.4-93.7 cm3). CK plans were generated for comparison. RESULTS Both the CK and LA plans accomplished appropriate dose coverage and normal tissue sparing. Compared with the LA plans, the CK plans achieved significantly lower gradient indices (3.12 ± 0.71 vs. 3.48 ± 0.55, p = 0.031) and gradient measures (1.00 ± 0.29 cm vs. 1.17 ± 0.29 cm, p < 0.001). They had similar equivalent conformity indices (CK vs. LA: 0.84 ± 0.08 vs. 0.87 ± 0.07, p = 0.093) and maximum doses 2 cm from the planning target volume (PTV) in any direction (CK vs. LA: 50.8 ± 9.9% vs. 53.1 ± 5.3%, p = 0.423). The dosimetric advantages of CK were more prominent in patients with a PTV of ≤ 50 cm3 or a spherical PTV. In patients with a PTV of > 50 cm3 or a non-spherical PTV, the LA and CK plans were similar regarding dosimetric parameters. CK plans involved more beams (232.2 ± 110.8 beams vs. 10.0 ± 1.7 arcs) and longer treatment times (119.2 ± 43.3 min vs. 22.4 ± 1.6 min, p = 0.007). CONCLUSIONS Both CK and LA are ideal modalities for noninvasive cardiac radio-ablation. Upfront treatment should be considered based on clinical intent.
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Affiliation(s)
- Ching-Yu Wang
- Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan
| | - Li-Ting Ho
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Lian-Yu Lin
- Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Hsing-Min Chan
- Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan
| | - Hung-Yi Chen
- Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan
| | - Tung-Lin Yu
- Department of Radiation Oncology, Fu-Jen Catholic University Hospital, Taipei, Taiwan
| | - Yu-Sen Huang
- Department of Medical Imaging, National Taiwan University Hospital, No. 7, Chung-Shan S. Rd., Taipei, 100, Taiwan
- Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Sung-Hsin Kuo
- Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan
- Department of Radiation Oncology, National Taiwan University Cancer Center, No. 57, Ln. 155, Sec. 3, Keelung Rd., Taipei, 106, Taiwan
| | - Wen-Jeng Lee
- Department of Medical Imaging, National Taiwan University Hospital, No. 7, Chung-Shan S. Rd., Taipei, 100, Taiwan.
- Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan.
| | - Jenny Ling-Yu Chen
- Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan.
- Department of Radiation Oncology, National Taiwan University Cancer Center, No. 57, Ln. 155, Sec. 3, Keelung Rd., Taipei, 106, Taiwan.
- Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan.
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Wu N, Wang Z, Guo X, Zhao H. Dose-effect relationship of linear accelerator based stereotactic radiotherapy for brain metastases. Radiat Oncol 2023; 18:177. [PMID: 37904212 PMCID: PMC10617179 DOI: 10.1186/s13014-023-02360-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 10/08/2023] [Indexed: 11/01/2023] Open
Abstract
OBJECTIVE The purpose of this study is to reveal the dose-effect relationship of linear accelerator (LINAC)-based stereotactic radiotherapy (SRT) in patients with brain metastases (BM). MATERIALS AND METHODS The PubMed, Cochrane, and Web of Science databases were used to identify studies that reported local tumour control after LINAC-based SRT in patients with BMs. Studies of other approaches that could affect local tumour control, such as whole brain radiotherapy, targeted therapy, and immunotherapy, were excluded from the dose-effect relationship analysis. Data extracted included patient and treatment characteristics and tumour local control. Probit model in XLSTAT 2016 was used for regression analysis, and P < 0.05 was set as the statistically significant level. RESULTS After literature screening, 19 eligible studies involving 1523 patients were included in the probit model regression analysis. There was no significant dose-effect relationship between nominal BED10 and peripheral BED10 versus 12-month local control probability. There were significant dose effect relationships between the centre BED10 and the average BED10 versus the 12-month local control probability, with P values of 0.015 and 0.011, respectively. According to the model, the central BED10 and the average BED10 corresponding to probabilities of 90% 12-month local control were 109.2 GyBED10 (95% confidence interval (CI): 88.7-245.9 GyBED10) and 87.8 GyBED10 (95% CI: 74.3-161.5 GyBED10), respectively. A 12-month local control rate of 86.9% (95% CI: 81.7-89.7%) and 85.5% (95% CI: 81.2-89.2%) can be expected at a centre BED10 of 80 Gy and an average BED10 of 60 Gy, respectively. CONCLUSION For patients with BM treated with LINAC-based SRT, more attention should be given to the central and average doses of PTV. A clear definition of the dose prescription should be established to ensure the effectiveness and comparability of treatment.
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Affiliation(s)
- Ning Wu
- Department of Radiation Oncology, China-Japan Union Hospital of Jilin University, No. 126, Xiantai Street, 130033, Changchun City, Jilin, PR China
| | - Zhiqiang Wang
- Department of Radiation Oncology, China-Japan Union Hospital of Jilin University, No. 126, Xiantai Street, 130033, Changchun City, Jilin, PR China
| | - Xin Guo
- Department of Radiation Oncology, China-Japan Union Hospital of Jilin University, No. 126, Xiantai Street, 130033, Changchun City, Jilin, PR China
| | - Hongfu Zhao
- Department of Radiation Oncology, China-Japan Union Hospital of Jilin University, No. 126, Xiantai Street, 130033, Changchun City, Jilin, PR China.
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Ganesh S, Jasper A, Backianathan S, Moorthy RK, Balakrishnan R, Sebastian P, Moses V, Godson HF, Keshava SN, Rajshekhar V. Correlation Between Post-Radiosurgery Perinidal Hyperintensity and AVM Obliteration Following LINAC-Based Stereotactic Radiosurgery. World Neurosurg 2023; 178:e189-e201. [PMID: 37454908 DOI: 10.1016/j.wneu.2023.07.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023]
Abstract
OBJECTIVE We studied the correlation between new-onset perinidal hyperintensity (PH) on T2-weighted magnetic resonance imaging and obliteration of intracranial arteriovenous malformation (AVM) after stereotactic radiosurgery (SRS). METHODS A retrospective study of 148 patients with an intracranial AVM who underwent SRS between September 2005 and June 2018 and had ≥1 radiological follow-up (early magnetic resonance imaging) 12-18 months after SRS was performed to analyze the correlation between PH (graded from 0 to 2) and AVM obliteration. RESULTS Of the 148 patients, 95 were male. The mean patient age was 27.7 ± 12.4 years. Of the 148 AVMs, 105 (70.9%) were obliterated at a median follow-up of 27 months (interquartile range, 14-48 months). The cumulative 3-, 5-, 10-year obliteration rate was 51.8%, 70.8%, and 91.8%, respectively. New-onset PH was observed in 58 AVMs (39.2%; 50 obliterated and 8 not obliterated). No association was found between the pretreatment variables or dose delivered and the development of PH. Grade 2 PH was associated with the risk of symptoms developing compared with grade 1 PH (37.5% vs. 4%; P = 0.002). Symptomatic PH was more likely to develop in patients with a larger AVM (P = 0.05). On multivariate analysis, the presence of a single draining vein (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.3-6.8), a lower median AVM volume (OR, 0.97; 95% CI, 0.6-0.89), a mean marginal radiation dose (OR, 1.29; 95% CI, 1.02-1.64), and the presence of PH (OR, 3.16; 95% CI, 1.29-7.71) were independent predictors of AVM obliteration. CONCLUSIONS The incidence of PH after SRS for AVM was 39.2%. PH was an independent predictor of AVM obliteration after SRS. Grade 2 PH and a larger AVM volume were associated with symptomatic PH.
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Affiliation(s)
- Swaminathan Ganesh
- Department of Neurological Sciences, Christian Medical College, Vellore, India
| | - Anitha Jasper
- Department of Radiodiagnosis, Christian Medical College, Vellore, India
| | | | - Ranjith K Moorthy
- Department of Neurological Sciences, Christian Medical College, Vellore, India.
| | | | - Patricia Sebastian
- Department of Radiation Oncology, Christian Medical College, Vellore, India
| | - Vinu Moses
- Department of Radiodiagnosis, Christian Medical College, Vellore, India
| | | | | | - Vedantam Rajshekhar
- Department of Neurological Sciences, Christian Medical College, Vellore, India
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10
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Bodensohn R, Kaempfel AL, Boulesteix AL, Orzelek AM, Corradini S, Fleischmann DF, Forbrig R, Garny S, Hadi I, Hofmaier J, Minniti G, Mansmann U, Pazos Escudero M, Thon N, Belka C, Niyazi M. Stereotactic radiosurgery versus whole-brain radiotherapy in patients with 4-10 brain metastases: A nonrandomized controlled trial. Radiother Oncol 2023; 186:109744. [PMID: 37330054 DOI: 10.1016/j.radonc.2023.109744] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 05/09/2023] [Accepted: 06/07/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND AND PURPOSE There is no randomized evidence comparing whole-brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS) in the treatment of multiple brain metastases. This prospective nonrandomized controlled single arm trial attempts to reduce the gap until prospective randomized controlled trial results are available. MATERIAL AND METHODS We included patients with 4-10 brain metastases and ECOG performance status ≤ 2 from all histologies except small-cell lung cancer, germ cell tumors, and lymphoma. The retrospective WBRT-cohort was selected 2:1 from consecutive patients treated within 2012-2017. Propensity-score matching was performed to adjust for confounding factors such as sex, age, primary tumor histology, dsGPA score, and systemic therapy. SRS was performed using a LINAC-based single-isocenter technique employing prescription doses from 15-20Gyx1 at the 80% isodose line. The historical control consisted of equivalent WBRT dose regimens of either 3Gyx10 or 2.5Gyx14. RESULTS Patients were recruited from 2017-2020, end of follow-up was July 1st, 2021. 40 patients were recruited to the SRS-cohort and 70 patients were eligible as controls in the WBRT-cohort. Median OS, and iPFS were 10.4 months (95%-CI 9.3-NA) and 7.1 months (95%-CI 3.9-14.2) for the SRS-cohort, and 6.5 months (95%-CI 4.9-10.4), and 5.9 months (95%-CI 4.1-8.8) for the WBRT-cohort, respectively. Differences were non-significant for OS (HR: 0.65; 95%-CI 0.40-1.05; P =.074) and iPFS (P =.28). No grade III toxicities were observed in the SRS-cohort. CONCLUSION This trial did not meet its primary endpoint as the OS-improvement of SRS compared to WBRT was non-significant and thus superiority could not be proven. Prospective randomized trials in the era of immunotherapy and targeted therapies are warranted.
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Affiliation(s)
- Raphael Bodensohn
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
| | - Anna-Lena Kaempfel
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Anne-Laure Boulesteix
- Institute for Medical Information Processing, Biometry and Epidemiology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Anna Maria Orzelek
- Institute for Medical Information Processing, Biometry and Epidemiology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Daniel Felix Fleischmann
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; German Cancer Consortium (DKTK), Munich, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Robert Forbrig
- Institute of Neuroradiology, University Hospital, LMU Munich, Munich, Germany
| | - Sylvia Garny
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Indrawati Hadi
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Jan Hofmaier
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Giuseppe Minniti
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy; IRCCS Istituto Neurologico Mediterraneo Neuromed, Pozzilli, Italy
| | - Ulrich Mansmann
- Institute for Medical Information Processing, Biometry and Epidemiology, Faculty of Medicine, LMU Munich, Munich, Germany
| | | | - Niklas Thon
- Department of Neurosurgery, University Hospital, LMU Munich, Munich, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; German Cancer Consortium (DKTK), Munich, Germany; Department of Neurosurgery, University Hospital, LMU Munich, Munich, Germany
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany; German Cancer Consortium (DKTK), Munich, Germany; Bavarian Cancer Research Center (BZKF), Munich, Germany.
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11
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He Z, Ho MKJ, Lee WYV, Law HY, Wong YWV, Leung TW, Mui WH, Wong ST, Wong CSF, Yam KY. Frameless versus frame-based stereotactic radiosurgery for intracranial arteriovenous malformations: A propensity-matched analysis. Clin Transl Radiat Oncol 2023; 41:100642. [PMID: 37304170 PMCID: PMC10248791 DOI: 10.1016/j.ctro.2023.100642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/13/2023] Open
Abstract
Objective The frameless linear accelerator (LINAC) based stereotactic radiosurgery (SRS) has been evolving with a reduction in patient discomfort. However, there was limited evidence comparing frame-based and frameless SRS for intracranial arteriovenous malformations (AVM). We aimed to compare the treatment outcomes between frame-based and frameless LINAC SRS. Materials and Methods This retrospective cohort compared the outcomes of frame-based LINAC SRS (1998-2009) with frameless LINAC SRS (2010-2020). The primary outcome was the obliteration rate. The other outcomes included the neurological, radiological, and functional outcomes after SRS. A matched cohort was identified by propensity scores for further comparisons. Results A total of 65 patients were included with a mean follow-up time of 13.2 years (158.5 months). There were 40 patients in the frame-based group and 25 patients in the frameless group. The overall obliteration rate was comparable (Frame-based 82.5% vs Frameless 80.0%, p = 0.310) and not significantly different over time (log-rank p = 0.536). The crude post-SRS hemorrhage rate was 1.5% and the incidence was 0.3 per 100 person-years. There were 67.7% of patients with AVM obliteration without new persistent neurological deficits at the last visit and 56.9% of patients with AVM obliteration without any deficits (transient or persistent) during the entire follow-up period. Four patients (8.0%) developed late onset persistent adverse radiation effects (more than 96 months after SRS) among 50 patients with more than 8-year surveillance. In the propensity-matched cohort of 42 patients, there was no significant difference in AVM obliteration (Frame-based vs Frameless, log-rank p = 0.984). Conclusion Frameless and frame-based LINAC SRS have comparable efficacy in intracranial AVM obliteration. A longer follow-up duration may further characterize the rate of late adverse radiation effects in frameless SRS.
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Affiliation(s)
- Zhexi He
- Department of Neurosurgery, Tuen Mun Hospital, N.T., Hong Kong, China
| | - Man Kit Jason Ho
- Department of Neurosurgery, Tuen Mun Hospital, N.T., Hong Kong, China
| | - Wan Yan Venus Lee
- Department of Clinical Oncology, Tuen Mun Hospital, N.T., Hong Kong, China
| | - Hing Yuen Law
- Department of Neurosurgery, Tuen Mun Hospital, N.T., Hong Kong, China
| | - Yee Wa Victy Wong
- Department of Clinical Oncology, Tuen Mun Hospital, N.T., Hong Kong, China
| | - To-wai Leung
- Department of Clinical Oncology, Tuen Mun Hospital, N.T., Hong Kong, China
| | - Wing Ho Mui
- Department of Clinical Oncology, Tuen Mun Hospital, N.T., Hong Kong, China
| | - Sui-To Wong
- Department of Neurosurgery, Tuen Mun Hospital, N.T., Hong Kong, China
| | | | - Kwong Yui Yam
- Department of Neurosurgery, Tuen Mun Hospital, N.T., Hong Kong, China
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12
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Ortholan C, Colin P, Serrano B, Bouet T, Garnier N, le Guyader M, Amblard R, Villeneuve R, Chanalet S, Alchaar H, Bozzolo E, Lanteri-Minet M, Fontaine D. Radiosurgery for classical trigeminal neuralgia: impact of the shot size on clinical outcome. J Headache Pain 2023; 24:51. [PMID: 37170187 PMCID: PMC10173482 DOI: 10.1186/s10194-023-01583-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/21/2023] [Indexed: 05/13/2023] Open
Abstract
BACKGROUND This study compares the outcome of patients suffering from medically refractory classical trigeminal neuralgia (TN) after treatment with radiosurgery using two different shot sizes (5- and 6-mm). METHODS All patients included in this open, prospective, non-controlled study were treated in a single institution for TN (95 cases in 93 patients) with LINear ACcelerators (LINAC) single-dose radiosurgery using a 5-mm shot (43 cases) or 6-mm shot (52 cases). The target was positioned on the intracisternal part of the trigeminal nerve. RESULTS The mean Dmax (D0.035) to the brainstem was higher in the 6-mm group: 12.6 vs 21.3 Gy (p < 0.001). Pain relief was significantly better in the 6-mm group: at 12 and 24 months in the 6-mm group the rate of pain-free patients was 90.2 and 87.8%, respectively vs. 73.6 and 73.6% in the 5-mm group (p = 0.045). At 12 and 24 months post-radiosurgical hypoesthesia was more frequent in the 6-mm group: 47.0 and 58% vs.11.3 and 30.8% in the 5-mm group (p = 0.002). To investigate the effect of cone diameter and the dose to the brainstem on outcomes, patients were stratified into three groups: group 1 = 5-mm shot, (all Dmax < 25 Gy, 43 cases), group 2 = 6-mm shot, Dmax < 25 Gy (32 cases), group 3 = 6-mm shot Dmax > 25 Gy (20 cases). At 12 months the rates of hypoesthesia were 11.3, 33.5 and 76.0%, respectively in groups 1, 2 and 3 (p < 0.001) and the rates of recurrence of pain were 26.4, 16.5 and 5%, respectively, (p = 0.11). CONCLUSION LINAC treatment with a 6-mm shot provided excellent control of pain, but increased the rate of trigeminal nerve dysfunction, especially when the maximum dose to the brainstem was higher than 25 Gy.
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Affiliation(s)
- Cécile Ortholan
- Department of Radiotherapy, Centre Hospitalier Princesse Grace, Monaco, Monaco.
- Department of Radiation Oncology, Centre Hospitalier Princesse Grace, Monaco, 98000, Monaco.
| | - Philippe Colin
- Department of Radiotherapy, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Benjamin Serrano
- Department of Medical Physics, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Thibault Bouet
- Pain Clinic, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
| | - Nicolas Garnier
- Department of Medical Physics, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Maud le Guyader
- Department of Radiotherapy, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Regis Amblard
- Department of Medical Physics, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Rémy Villeneuve
- Department of Medical Physics, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Stéphane Chanalet
- Department of Radiology, Centre Hospitalier Princesse Grace, Monaco, Monaco
- Department of Radiology, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
| | - Haiel Alchaar
- Pain Clinic, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
| | - Eric Bozzolo
- Pain Clinic, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
- FHU Inovpain, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
| | - Michel Lanteri-Minet
- Pain Clinic, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
- FHU Inovpain, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
- INSERM/UdA, U1107, Neuro-Dol, Trigeminal Pain and Migraine, University Clermont-Auvergne, Clermont-Ferrand, France
| | - Denys Fontaine
- FHU Inovpain, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
- Department of Neurosurgery, Centre Hospitalier Universitaire de Nice, Université Côte d'Azur, Nice, France
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13
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Ikawa T, Kanayama N, Arita H, Ohira S, Takano K, Hirata T, Morimoto M, Teshima T, Konishi K. Linear accelerator-based stereotactic radiotherapy for brain metastases, including multiple and large lesions, carries a low incidence of acute toxicities: a retrospective analysis. Radiat Oncol 2023; 18:80. [PMID: 37165431 PMCID: PMC10173492 DOI: 10.1186/s13014-023-02262-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/11/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Data on acute toxicities after stereotactic radiotherapy (SRT) for brain metastases, including multiple and large lesions, are lacking. We aimed to evaluate the incidence and nature of toxicities immediately after SRT using a linear accelerator. METHODS This retrospective study reviewed the medical records of 315 patients with brain metastases treated with SRT at our institution between May 2019 and February 2022. In total, 439 SRT sessions were performed for 2161 brain metastases. The outcome of interest was immediate side effects (ISEs), defined as new or worsening symptoms occurring during SRT or within 14 days after the end of SRT. RESULTS Grade ≥ 2 and ≥ 3 ISEs occurred in 16 (3.6%) and 7 (1.6%) cases, respectively. Among 63 treatments for 10 or more lesions (range: 10-40), 1 (1.6%) ISE occurred. Among 22 treatments for lesions with a maximum tumor volume of > 10 cc, 2 (9.1%) ISEs occurred. Grade ≥ 3 ISEs included 1, 4, 1, and 1 cases of grade 3 nausea, grade 3 new-onset partial and generalized seizures, grade 3 obstructive hydrocephalus, and grade 5 intracranial hemorrhage, respectively. ISEs were more common in patients with a larger maximum tumor volume, primary sites other than lung and breast cancer, and pre-treatment neurological symptoms. CONCLUSION SRT using a linear accelerator for brain metastases, including multiple and large lesions, is safe, with a low incidence of ISEs. Serious complications immediately after SRT are rare but possible; therefore, careful follow-up is necessary after treatment initiation.
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Affiliation(s)
- Toshiki Ikawa
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan.
| | - Naoyuki Kanayama
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
| | - Hideyuki Arita
- Department of Neurosurgery, Osaka International Cancer Institute, Osaka, Japan
| | - Shingo Ohira
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
| | - Koji Takano
- Department of Neurosurgery, Osaka International Cancer Institute, Osaka, Japan
| | - Takero Hirata
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masahiro Morimoto
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
| | | | - Koji Konishi
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
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14
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Cook N, Shelton N, Gibson S, Barnes P, Alinaghi-Zadeh R, Jameson MG. ACPSEM position paper: the safety of magnetic resonance imaging linear accelerators. Phys Eng Sci Med 2023; 46:19-43. [PMID: 36847966 PMCID: PMC10030425 DOI: 10.1007/s13246-023-01224-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2023] [Indexed: 03/01/2023]
Abstract
Magnetic Resonance Imaging linear-accelerator (MRI-linac) equipment has recently been introduced to multiple centres in Australia and New Zealand. MRI equipment creates hazards for staff, patients and others in the MR environment; these hazards must be well understood, and risks managed by a system of environmental controls, written procedures and a trained workforce. While MRI-linac hazards are similar to the diagnostic paradigm, the equipment, workforce and environment are sufficiently different that additional safety guidance is warranted. In 2019 the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) formed the Magnetic Resonance Imaging Linear-Accelerator Working Group (MRILWG) to support the safe clinical introduction and optimal use of MR-guided radiation therapy treatment units. This Position Paper is intended to provide safety guidance and education for Medical Physicists and others planning for and working with MRI-linac technology. This document summarises MRI-linac hazards and describes particular effects which arise from the combination of strong magnetic fields with an external radiation treatment beam. This document also provides guidance on safety governance and training, and recommends a system of hazard management tailored to the MRI-linac environment, ancillary equipment, and workforce.
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Affiliation(s)
- Nick Cook
- Christchurch Hospital, Christchurch, New Zealand
| | - Nikki Shelton
- Olivia Newton-John Cancer Wellness and Research Centre, Heidelberg, VIC, Australia
| | | | | | - Reza Alinaghi-Zadeh
- Olivia Newton-John Cancer Wellness and Research Centre, Heidelberg, VIC, Australia
| | - Michael G Jameson
- GenesisCare, Sydney, NSW, Australia.
- University of New South Wales, Sydney, Australia.
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15
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Bin-Alamer O, Alnefaie N, Qedair J, Chaudhary A, Hallak H, Abdulbaki A, Mallela AN, Palmisciano P, Gersey ZC, Legarreta AD, Labib MA, Zada G, Sheehan JP, Couldwell WT, Lunsford LD, Abou-Al-Shaar H. Single session versus multisession stereotactic radiosurgery for the management of intracranial meningiomas: a systematic review and meta-analysis. J Neurooncol 2023; 161:215-224. [PMID: 35976546 DOI: 10.1007/s11060-022-04112-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 08/03/2022] [Indexed: 10/15/2022]
Abstract
PURPOSE To compare the efficacy, outcomes, and complications of single session (SS-SRS) and multisession (MS-SRS) stereotactic radiosurgery in the treatment of intracranial meningiomas. METHODS Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane. A systematic review and meta-analysis of treatment protocols and outcomes were conducted. After the selection process, 20 articles describing 1483 cases were included. RESULTS A total of 1303 patients who underwent SS-SRS and 180 patients who underwent MS-SRS for the management of their intracranial meningioma were reported in the included studies. SS-SRS and MS-SRS had comparable one-year (SS-SRS: 98% vs. MS-SRS: 100%, p > 0.99) and five-year (SS-SRS: 94% vs. MS-SRS: 93%, p = 0.71) tumor control rates. The groups also had comparable tumor volume reduction/tumor regression rates (SS-SRS: 44% vs. MS-SRS: 25%, p = 0.25), tumor volume stability rates (SS-SRS: 51% vs. MS-SRS: 75%, p = 0.12), and tumor progression rates (SS-SRS: 4% vs. MS-SRS: 4%, p = 0.89). SS-SRS and MS-SRS yielded similar complication rates (10.4% vs. 11.4%, p = 0.68) and comparable functional improvement rates (MS-SRS: 44% vs. SS-SRS: 36%, p = 0.57). However, MS-SRS was used for significantly larger tumor volumes (MS-SRS: 23.8 cm3 vs. SS-SRS: 6.1 cm3, p = 0.02). CONCLUSION SS-SRS and MS-SRS resulted in comparable tumor control, tumor volumetric change, and functional outcomes despite significant biases in selecting patients for SS- or MS-SRS.
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Affiliation(s)
- Othman Bin-Alamer
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Nada Alnefaie
- Department of Neurosurgery, National Neurosciences Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Jumanah Qedair
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Adhiraj Chaudhary
- Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Hana Hallak
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Arif Abdulbaki
- Department of Neurosurgery, Hannover Medical School, Hannover, Germany
| | - Arka N Mallela
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Paolo Palmisciano
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Zachary C Gersey
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Andrew D Legarreta
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Mohamed A Labib
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gabriel Zada
- Department of Neurosurgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jason P Sheehan
- Department of Neurosurgery, University of Virginia Health System, Charlottesville, VA, USA
| | - William T Couldwell
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, UT, USA
| | - L Dade Lunsford
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Hussam Abou-Al-Shaar
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
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Shukla SK, Shukla S. Development of Cancer Management and Care in Central India. Indian J Surg Oncol 2022; 13:54-57. [PMID: 36691513 PMCID: PMC9859949 DOI: 10.1007/s13193-022-01568-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/09/2022] [Indexed: 01/25/2023] Open
Abstract
This is a survey report regarding the facilities of Cancer Management in Central India, consisting of Madhya Pradesh, Chhatisgarh and Rajasthan. These three states are considered less developed states medically in comparison to the northern, western and southern states. Madhya Pradesh with large population has more than 7 cities having many cancer institution/hospitals with advanced radiation centre and surgical/radiological units to improve diagnosis and management. Similarly, Chhatisgarh, a tribal state, is advancing forward with 3 centres of Advance Management for Cancer Patient. Rajasthan, Jaipur is the main centre of Advance Cancer Management with many private units operating, benefitting a large population in the state. Beside this, 5 more cities have centres of excellence in treating cancer patients with advanced radiation facilities, expert oncology surgeon and investigative facilities required in investigation and diagnosis.
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Affiliation(s)
- Satish K. Shukla
- Lakshmi Memorial Hospital and Research Centre, 1/2, New Palasia, Indore, 452 001 M.P. India
- M.G.M. Medical College & M.Y. Group of Hospitals, Indore, 452 001 M.P. India
| | - Sumit Shukla
- M.G.M. Medical College & M.Y. Group of Hospitals, Indore, 452 001 M.P. India
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17
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De La Peña NM, Singh R, Anderson ML, Koester SW, Sio TT, Ashman JB, Vora SA, Patel NP. High-Dose Frameless Stereotactic Radiosurgery for Trigeminal Neuralgia: A Single-Institution Experience and Systematic Review. World Neurosurg 2022; 167:e432-e443. [PMID: 35973520 DOI: 10.1016/j.wneu.2022.08.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 08/08/2022] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Stereotactic radiosurgery is an effective treatment option for trigeminal neuralgia (TN), with frameless stereotactic radiosurgery (fSRS) allowing for a less invasive experience. A single-institutional series and systematic review of the literature were performed for cases of TN treated with fSRS. METHODS Patients at our institution with TN that were treated with fSRS from the years 2012-2021 were included. Similarly, multiple databases were searched for studies regarding TN treated with fSRS where patient-level data was included from 2004-2020. Pain levels, via the Barrow Neurological Institute (BNI) scale, before and after treatment were analyzed. Pooled analysis was performed to compare treatment outcomes between studies using CyberKnife and LINAC modalities. RESULTS Twenty-three patients at our institution were treated with LINAC fSRS (median treatment dose: 85 Gy). Most patients had TN refractory to previous procedural treatments. Eight (35%) patients had an excellent posttreatment response (BNI I-II), while 11 (48%) patients had a good result (BNI IIIa/b). Eight patients had recurrence of pain. A total of 30 articles were included in the systematic review, encompassing 1705 patients. At last follow-up, 63.1% (774/1227) of patients endorsed an excellent response, while 16.1% (197/1227) had a good response, and 22.5% (215/957) of patients had recurrence. Pain response, facial numbness rates, and pain recurrence rates were not significantly different between CyberKnife and LINAC modalities. CONCLUSIONS Frameless SRS for TN appears to be an efficacious noninvasive option for patients with substantial comorbidities, who have failed other treatment methods, although it can be limited by higher recurrence rates.
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Affiliation(s)
| | - Rohin Singh
- Mayo Clinic Alix School of Medicine, Scottsdale, Arizona, USA
| | | | - Stefan W Koester
- Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Terence T Sio
- Department of Radiation Oncology, Mayo Clinic Hospital, Phoenix, Arizona, USA
| | - Jonathan B Ashman
- Department of Radiation Oncology, Mayo Clinic Hospital, Phoenix, Arizona, USA
| | - Sujay A Vora
- Department of Radiation Oncology, Mayo Clinic Hospital, Phoenix, Arizona, USA
| | - Naresh P Patel
- Department of Neurological Surgery, Mayo Clinic Hospital, Phoenix, Arizona, USA
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Mark F, Jin AH, Zacest A, Govindaraj R, Esterman A, Gorayski P, Abou-Hamden A, Roos D. LINAC stereotactic radiosurgery for brain arteriovenous malformations: An updated single centre analysis of outcomes. J Clin Neurosci 2022; 102:54-9. [PMID: 35728395 DOI: 10.1016/j.jocn.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 06/03/2022] [Accepted: 06/05/2022] [Indexed: 10/18/2022]
Abstract
Arteriovenous malformations (AVM) of the brain are congenital, high pressure vascular malformations, which are at risk of haemorrhage. Stereotactic radiosurgery (SRS) can obliterate the nidus by delivering a precise high dose of ionising radiation in a single fraction. This paper updates long term AVM obliteration rates, time to obliteration and retreatment outcomes in LINAC delivered SRS treatment at the Royal Adelaide Hospital. A retrospective review of a prospectively maintained AVM SRS database supplemented by clinical case notes, patient correspondence and electronic medical records was performed. 89 AVMs received primary SRS treatment for which the crude obliteration rate was 61% (68% for 79 patients with adequate follow up). Higher marginal dose, smaller nidus size and lower Pollock-Flickinger (PF) score were significantly associated with AVM obliteration. The crude obliteration rates for patients with adequate follow-up and AVM diameter < 3 cm vs ≥ 3 cm were 76% vs 48%, respectively, and 93% with PF score < 1.0. Median time to obliteration was 36 months. Higher dose and lower PF score were associated with earlier obliteration. The crude obliteration rate after second SRS was 56% (9/16 patients) and no significant associations were found. These obliteration rates after primary and retreatment LINAC SRS are comparable to other studies. Marginal dose and PF score were the main predictors of obliteration overall as well as early (<36 months) obliteration.
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19
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Peet SC, Cassim N, Kairn T, Trapp JV, Crowe SB. A publicly available dataset of out-of-field dose profiles of a 6 MV linear accelerator. Phys Eng Sci Med 2022. [PMID: 35553016 DOI: 10.1007/s13246-022-01131-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 04/19/2022] [Indexed: 10/18/2022]
Abstract
An increase in radiotherapy-induced secondary malignancies has led to recent developments in analytical modelling of out-of-field dose. These models must be validated against measurements, but currently available datasets are outdated or limited in scope. This study aimed to address these shortcomings by producing a large dataset of out-of-field dose profiles measured with modern equipment. A novel method was developed with the intention of allowing physicists in all clinics to perform these measurements themselves using commonly available dosimetry equipment. A standard 3D scanning water tank was used to collect 36 extended profiles. Each profile was measured in two sections, with the inner section measured with the beam directly incident on the tank, and the outer section with the beam incident on a water-equivalent phantom abutted next to the tank. The two sections were then stitched using a novel feature-matching approach. The profiles were compared against linac commissioning data and manually inspected for discontinuities in the overlap region. The dataset is presented as a publicly accessible comma separated variable file containing off-axis ratios at a range of off-axis distances. This dataset may be applied to the development and validation of analytical models of out-of-field dose. Additionally, it may be used to inform dose estimates to radiosensitive implants and anatomy. Physicists are encouraged to perform these out-of-field measurements in their own clinics and share their results with the community.
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20
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Kostjuchenko VV, Golanov AV. LINAC-based radiosurgery for functional and psychiatric disorders: Problems and their solutions. Prog Brain Res 2022; 270:197-209. [PMID: 35396028 DOI: 10.1016/bs.pbr.2022.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Stereotactic radiosurgery (SRS) is practically non-invasive treatment option, and its application for ablative procedures in functional and psychiatric brain disorders seems rather promising. In such cases, gamma knife surgery (GKS) is considered a standard option due to its proved accuracy in targeting and dosimetry. However, modern linear accelerators (LINAC), which are the most commonly used radiosurgical device, provide comparable treatment preciseness. Although at present experience with LINAC-based SRS of functional brain disorders is rather limited, from the technological viewpoint it definitely seems possible and theoretically may be of the similar efficacy as established with GKS for the same indications. However, widespread introduction of such practice requires resolution of several important methodological issues, particularly related to establishment of specific treatment standards, development of dedicated training for involved medical professionals, and creation of the data accumulation and outcome analysis systems.
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Affiliation(s)
| | - Andrey V Golanov
- Gamma Knife Center of JSC Neurosurgery Business Center, Moscow, Russian Federation; Department of Stereotactic Radiotherapy and Radiosurgery, Burdenko National Medical Research Center of Neurosurgery, Moscow, Russian Federation
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21
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Doudard A, Guérin C, Dufreneix S, Josset S. Design and automation of specific geometric quality controls for cone-radiosurgery treatments. Phys Med 2022; 96:1-8. [PMID: 35189430 DOI: 10.1016/j.ejmp.2022.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/12/2022] [Accepted: 02/12/2022] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The Varian TrueBeam STx linac can be equipped with BrainLAB stereotactic cones and ExacTrac imaging system for SRS treatments. However, these two third-party systems lack integration in a self-performance diagnosis tool dedicated to the SRS platform. The aim of this work was to design and automate essential geometric tests considering the complete set of cones with diameter range from 4 to 15 mm. METHODS EPID-based tests were focused on the cone alignment, the radiation isocentricity and the isocenters congruence. Images acquired with or without the BrainLAB pointer were analysed using the Hough transform and morphological filtering operations, after assessment of the algorithm accuracy using simulated images. The new Machine QA program was experimented over one year. RESULTS A subpixel resolution of 0.02 mm was found for the circular-field center detection algorithm. The tests results did not depend on the pointer location. The maximum deviations reported were in accordance with the AAPM SRS guidelines. The accurate localization of the linac radiation isocenter allowed for guidance of the ExacTrac calibration. A misalignment reaching 0.2 mm was measured for all cones but one, highlighting the benefit of systematizing this control before each patient SRS treatment. CONCLUSION An effective in-house QA program dedicated to SRS cones was developed to supplement the standard machine performance check on our mixed SRS platform. Specific geometric tests even include the smallest 4-mm cone, which could be of great interest for future clinical indications such as the radiosurgery of functional disorders.
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Affiliation(s)
- A Doudard
- Department of Medical Physics, Institut de Cancérologie de l'Ouest, Saint-Herblain/Angers, France
| | - C Guérin
- Department of Medical Physics, Institut de Cancérologie de l'Ouest, Saint-Herblain/Angers, France
| | - S Dufreneix
- Department of Medical Physics, Institut de Cancérologie de l'Ouest, Saint-Herblain/Angers, France
| | - S Josset
- Department of Medical Physics, Institut de Cancérologie de l'Ouest, Saint-Herblain/Angers, France.
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22
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Kutsaev SV, Agustsson R, Berry R, Boucher S, Bruhwiler D, Schulze K, Smirnov AY, Taletski K. Ir-192 radioisotope replacement with a hand-portable 1 MeV Ku-band electron linear accelerator. Appl Radiat Isot 2021; 179:110029. [PMID: 34814009 DOI: 10.1016/j.apradiso.2021.110029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/24/2021] [Accepted: 11/10/2021] [Indexed: 11/26/2022]
Abstract
Although linear accelerators are used in many security, industrial and medical applications, the existing technologies are too large and expensive for several critical applications such as radioactive source replacement, field radiography and mobile cargo scanners. One of the main requirements for these sources is to be highly portable to allow field operation. In response to this problem, RadiaBeam has designed a hand-portable 1 MeV X-ray source, scalable to higher energies, based on Ku-band split electron linac, that can be used for Ir-192 radioisotope replacement. In this paper, we present its multiphysics and engineering design studies, as well as an accelerating structure prototype along with RF measurements.
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Affiliation(s)
- S V Kutsaev
- RadiaBeam Technologies, LLC, Santa Monica, CA, 90404, USA.
| | - R Agustsson
- RadiaBeam Technologies, LLC, Santa Monica, CA, 90404, USA
| | - R Berry
- RadiaBeam Technologies, LLC, Santa Monica, CA, 90404, USA
| | - S Boucher
- RadiaBeam Technologies, LLC, Santa Monica, CA, 90404, USA
| | | | - K Schulze
- RadiaBeam Technologies, LLC, Santa Monica, CA, 90404, USA
| | - A Yu Smirnov
- RadiaBeam Technologies, LLC, Santa Monica, CA, 90404, USA
| | - K Taletski
- RadiaBeam Technologies, LLC, Santa Monica, CA, 90404, USA
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Caravani K, Murry R, Healy B. Characterisation of in-room leakage and scattered radiation for the Varian Halcyon linear accelerator. Phys Eng Sci Med 2021; 45:73-81. [PMID: 34797532 DOI: 10.1007/s13246-021-01084-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/15/2021] [Indexed: 10/19/2022]
Abstract
Unintended sources of secondary radiation resulting from photon beams in linear accelerators are patient scatter, collimator scatter, scatter from surfaces within the bunker, and head leakage. This work characterises the in-room leakage and scattered radiation for the Varian Halcyon linear accelerator. Scattered and leakage radiation for static gantry angles 0°, 45°, and 90° and largest field size 28 × 28 cm2 were measured with an ionisation chamber survey meter at a radial distance of 1.5 m from the isocentre. The scatter within the treatment room was characterised with isocontour maps from measurements of 360° arc deliveries with the largest field size 28 × 28 cm2 at various heights and distances from the isocentre. The transmission through the primary beam stopper was measured with a Farmer ionisation chamber. For static gantry angles, instantaneous dose rate readings were typically around 70 mSv/hr at 1.5 m from the isocentre with lower dose rates at room angles adjacent to the gantry. The head leakage was measured as less than 0.03% of the useful beam. In a full 360° arc, the radiation dose around the Halcyon was coldest in lateral areas, with hotter areas behind and in front of the gantry. The primary beam stopper transmission was measured as 0.019%, reducing the requirement of primary barriers in the shielding design by a factor of 1/500. The results presented in this study can be used to determine the out-of-field dose to patients and to inform bunker shielding designs for Halcyon linear accelerators.
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24
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Lim JX, Karlsson B, Pang A, Vellayappan BA, Nga V. Stereotactic radiosurgery in alveolar soft part sarcoma brain metastases: Case series and literature review. J Clin Neurosci 2021; 93:227-230. [PMID: 34656252 DOI: 10.1016/j.jocn.2021.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 06/21/2021] [Accepted: 09/02/2021] [Indexed: 11/18/2022]
Abstract
Alveolar soft part sarcoma (ASPS) has the highest incidence of brain metastasis amongst sarcomas. There is a paucity of literature published focusing on radiation therapy for this condition. This is a single centre retrospective review of the treatment of three patients with 12 ASPS brain metastasis using single dose stereotactic radiosurgery (SRS). Five lesions were treated with low (<25 Gy) and seven with high (≥25 Gy) dose. Four lesions had a volume of >1.5 cm3 and were defined as large, while seven had a volume of ≤0.5 cm3 and were defined as small. The local tumor control as well as the clinical complication rates were studied. There was a statistically significant relation between treatment dose and tumor control rate. All large tumors treated with low dose recurred and required surgical removal within two months following SRS, while the large lesion treated with high dose recurred after 11 months. Five of the six small tumors treated with high doses were controlled, while the sixth required retreatment and was stable thereafter. No patient suffered from undue symptomatic radiation effects. The success rate following SRS for small ASPS metastases treated with high doses seems to be sufficient to justify the treatment. The short time for large tumor to recur, significant increase in tumor size requiring surgical removal of the tumors, makes low dose SRS unattractive. Based on this limited patient population, it seems that high dose SRS should be used for all ASPS brain metastases except for large tumors deemed surgically accessible.
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Affiliation(s)
- Jia Xu Lim
- Department of Neurosurgery, National Neuroscience Institute, Singapore; Division of Neurosurgery, Department of Surgery, National University Hospital, Singapore.
| | - Bengt Karlsson
- Division of Neurosurgery, Department of Surgery, National University Hospital, Singapore
| | - Angela Pang
- Department of Haematology-Oncology, National University Cancer Institute, Singapore
| | | | - Vincent Nga
- Division of Neurosurgery, Department of Surgery, National University Hospital, Singapore
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25
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Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, Colak O, Ozcan F, Gundem E, Elcim Y, Dirican B, Beyzadeoglu M. Concise review of stereotactic irradiation for pediatric glial neoplasms: Current concepts and future directions. World J Methodol 2021; 11:61-74. [PMID: 34026579 PMCID: PMC8127424 DOI: 10.5662/wjm.v11.i3.61] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 04/07/2021] [Accepted: 04/14/2021] [Indexed: 02/06/2023] Open
Abstract
Brain tumors, which are among the most common solid tumors in childhood, remain a leading cause of cancer-related mortality in pediatric population. Gliomas, which may be broadly categorized as low grade glioma and high grade glioma, account for the majority of brain tumors in children. Expectant management, surgery, radiation therapy (RT), chemotherapy, targeted therapy or combinations of these modalities may be used for management of pediatric gliomas. Several patient, tumor and treatment-related characteristics including age, lesion size, grade, location, phenotypic and genotypic features, symptomatology, predicted outcomes and toxicity profile of available therapeutic options should be considered in decision making for optimal treatment. Management of pediatric gliomas poses a formidable challenge to the physicians due to concerns about treatment induced toxicity. Adverse effects of therapy may include neurological deficits, hemiparesis, dysphagia, ataxia, spasticity, endocrine sequelae, neurocognitive and communication impairment, deterioration in quality of life, adverse socioeconomic consequences, and secondary cancers. Nevertheless, improved understanding of molecular pathology and technological advancements may pave the way for progress in management of pediatric glial neoplasms. Multidisciplinary management with close collaboration of disciplines including pediatric oncology, surgery, and radiation oncology is warranted to achieve optimal therapeutic outcomes. In the context of RT, stereotactic irradiation is a viable treatment modality for several central nervous system disorders and brain tumors. Considering the importance of minimizing adverse effects of irradiation, radiosurgery has attracted great attention for clinical applications in both adults and children. Radiosurgical applications offer great potential for improving the toxicity profile of radiation delivery by focused and precise targeting of well-defined tumors under stereotactic immobilization and image guidance. Herein, we provide a concise review of stereotactic irradiation for pediatric glial neoplasms in light of the literature.
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Affiliation(s)
- Omer Sager
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Ferrat Dincoglan
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Selcuk Demiral
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Bora Uysal
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Hakan Gamsiz
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Onurhan Colak
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Fatih Ozcan
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Esin Gundem
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Yelda Elcim
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Bahar Dirican
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
| | - Murat Beyzadeoglu
- Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences, Ankara 06018, Turkey
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26
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Hachemi T, Chaoui ZEA, Khoudri S. PENELOPE simulations and experiment for 6 MV clinac iX accelerator for standard and small static fields. Appl Radiat Isot 2021; 174:109749. [PMID: 33940355 DOI: 10.1016/j.apradiso.2021.109749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 03/25/2021] [Accepted: 04/23/2021] [Indexed: 11/18/2022]
Abstract
The goal of this work was to produce accurate data for use as a 'gold standard' and a valid tool for measurements in reference dosimetry for standard/small static field sizes from 0.5 × 0.5 to 10 × 10 cm2. It is based on the accuracy of the phase space files (PSFs) as a key quantity. Because the IAEA general public database provides few PSFs for the Varian iX, we simulated the head through Monte Carlo (MC) simulations and calculated validated PSFs for 12 square field sizes including seven for small static fields. The resulting dosimetric calculations allowed us to reach a good level of agreement in comparison to our relative and absolute dose measurements performed on a Varian iX in water phantom. Measured and MC calculated output factors were investigated for different detectors. Based on the TRS 483 formalism and MC (PENELOPE/penEasy), we calculated output correction factors for the unshielded Diode-E (T60017) and the PinPoint-3D (T31016) micro-chamber according to manufacturers' blueprints. Our MC results were in agreement with the recommended data; they compete with recent measurements and MC simulations and in particular the TRS 483 MC data obtained from similar simulations. Moreover, our MC results provide supplemental data in comparison to TRS 483 data in particular for the PinPoint-3D (T31016). We suggest our MC output correction factors as new datasets for future TRS compilations. The work was substantial, used different robust MC strategies depending on the scoring regions, and led in most cases to uncertainties of less than 1%.
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Affiliation(s)
- Taha Hachemi
- Physics Department, Faculty of Sciences, Laboratory of Optoelectronic and Devices, University Ferhat Abbas Sétif 1, Algeria.
| | - Zine-El-Abidine Chaoui
- Physics Department, Faculty of Sciences, Laboratory of Optoelectronic and Devices, University Ferhat Abbas Sétif 1, Algeria
| | - Saad Khoudri
- Physics Department, Faculty of Sciences, Laboratory of Optoelectronic and Devices, University Ferhat Abbas Sétif 1, Algeria; Centre de Lutte Contre le Cancer de Sétif, Algeria
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Bodensohn R, Kaempfel AL, Fleischmann DF, Hadi I, Hofmaier J, Garny S, Reiner M, Forbrig R, Corradini S, Thon N, Belka C, Niyazi M. Simultaneous stereotactic radiosurgery of multiple brain metastases using single-isocenter dynamic conformal arc therapy: a prospective monocentric registry trial. Strahlenther Onkol 2021; 197:601-613. [PMID: 33884441 PMCID: PMC8219560 DOI: 10.1007/s00066-021-01773-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 03/23/2021] [Indexed: 12/25/2022]
Abstract
BACKGROUND Single-isocenter dynamic conformal arc (SIDCA) therapy is a technically efficient way of delivering stereotactic radiosurgery (SRS) to multiple metastases simultaneously. This study reports on the safety and feasibility of linear accelerator (LINAC) based SRS with SIDCA for patients with multiple brain metastases. METHODS All patients who received SRS with this technique between November 2017 and June 2019 within a prospective registry trial were included. The patients were irradiated with a dedicated planning tool for multiple brain metastases using a LINAC with a 5 mm multileaf collimator. Follow-up was performed every 3 months, including clinical and radiological examination with cranial magnetic resonance imaging (MRI). These early data were analyzed using descriptive statistics and the Kaplan-Meier method. RESULTS A total of 65 patients with 254 lesions (range 2-12) were included in this analysis. Median beam-on time was 23 min. The median follow-up at the time of analysis was 13 months (95% CI 11.1-14.9). Median overall survival and median intracranial progression-free survival was 15 months (95% CI 7.7-22.3) and 7 months (95% CI 3.9-10.0), respectively. Intracranial and local control after 1 year was 64.6 and 97.5%, respectively. During follow-up, CTCAE grade I adverse effects (AE) were experienced by 29 patients (44.6%; 18 of them therapy related, 27.7%), CTCAE grade II AEs by four patients (6.2%; one of them therapy related, 1.5%), and CTCAE grade III by three patients (4.6%; none of them therapy related). Two lesions (0.8%) in two patients (3.1%) were histopathologically proven to be radiation necrosis. CONCLUSION Simultaneous SRS using SIDCA seems to be a feasible and safe treatment for patients with multiple brain metastases.
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Affiliation(s)
- Raphael Bodensohn
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Anna-Lena Kaempfel
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Daniel Felix Fleischmann
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany.,German Cancer Consortium (DKTK), Munich, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Indrawati Hadi
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Jan Hofmaier
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Sylvia Garny
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Michael Reiner
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Robert Forbrig
- Institute of Neuroradiology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Niklas Thon
- Department of Neurosurgery, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany.,German Cancer Consortium (DKTK), Munich, Germany
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany. .,German Cancer Consortium (DKTK), Munich, Germany.
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Akomolafe IR, Chetty N. Radioprotective potential of <italic>Costus afer</italic> against the radiation-induced hematological and histopathological damage in mice. Radiat Oncol J 2021; 39:61-71. [PMID: 33794575 PMCID: PMC8024188 DOI: 10.3857/roj.2021.00017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/25/2021] [Indexed: 12/31/2022] Open
Abstract
Purpose This study investigated the possible radioprotective effect of Costus afer extract (CAE) on hematological and histopathological parameters of mice. Materials and Methods Fifty-four male mice with mass between 37–43 g, 11–13 weeks old were used for this study. We divided the mice into six different groups containing nine animals, which were then further sub-divided into irradiated groups and un-irradiated groups. Animals received 250 mg/kg body weight extract of CAE by oral gavage for 6 days in addition to feeding and water ad libitum. Animals in the irradiated group were exposed to radiation at the Department of Radiotherapy and Oncology, Grey’s Hospital using a linear accelerator. Blood samples were collected at 48-hour post-irradiation for the hematology test followed by histopathology examination of kidney and liver. Results Our findings revealed that 3 Gy and 6 Gy dose of X-ray radiation caused a significant reduction in the white blood cell, packed cell volume, hemoglobin, neutrophils, lymphocytes, eosinophils, and platelet counts compared with the control group. However, the administration of CAE before irradiation significantly increased the mentioned parameters. There was no increase in red blood cell and monocyte among treated groups compared with the control. Histopathological changes in the kidney and liver sections revealed that no visible lesion in the pretreated mice. Hepatocytes seem to be within normal histological limits. Conclusions This study concludes that CAE offered some protection against radiation-induced hematological alterations, but there was no significant improvement in the histopathological parameters. Thus, further studies are needed to validate its radioprotective effect on histopathological variables.
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Affiliation(s)
- Idowu Richard Akomolafe
- Discipline of Physics, School of Chemistry and Physics, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Naven Chetty
- Discipline of Physics, School of Chemistry and Physics, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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Asher AL, Alvi MA, Bydon M, Pouratian N, Warnick RE, McInerney J, Grills IS, Sheehan J. Local failure after stereotactic radiosurgery (SRS) for intracranial metastasis: analysis from a cooperative, prospective national registry. J Neurooncol 2021; 152:299-311. [PMID: 33481148 DOI: 10.1007/s11060-021-03698-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/08/2021] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Stereotactic radiosurgery (SRS) has been increasingly employed to treat patients with intracranial metastasis, both as a salvage treatment after failed whole brain radiation therapy (WBRT) and as an initial treatment. "Several studies have shown that SRS may be as effective as WBRT with the added benefit of preserving neuro-cognition". However, some patients may have local failure following SRS for intracranial metastasis, defined as increase in total lesion volume by 25% after at least 3 months of follow up. METHODS The SRS registry, established by the Neuro point alliance (NPA) under the auspices of the American Association of Neurological Surgeons (AANS), was queried for patients with intracranial metastasis receiving SRS at the participating sites. Demographic, clinical symptoms, tumor, and treatment characteristics as well as follow up status were summarized for the cohort. A multivariable explanatory cox- regression was performed to evaluate the impact of each of the factors on time to local failure.at last follow-up. RESULTS A total of 441 patients with 1255 intracranial metastatic lesions undergoing SRS were identified. The most common primary cancer histology was non-small cell lung cancer (43.8%, n = 193). More than half of the cohort had more than 1 metastatic lesion (2-3 lesions: 29.5%, n = 130; more than 3 lesions: 25.2% (n = 111). The average duration of follow-up for the cohort was found to be 8.4 months (SD = 7.61). The mean clinical treatment volume (CTV), after adding together the volume of each lesion for each patient was 5.39 cc (SD = 7.6) at baseline. A total of 20.2% (n = 89) had local failure (increase in volume by > 25%) with a mean time to progression of 7.719 months (SD = 6.09). The progression free survival (PFS) for the cohort at 3, 6 and 12 months were found to be 94.9%, 84.3%, and 69.4%, respectively. On multivariable cox regression analysis, factors associated with increased hazard of local failure included male gender (HR 1.65, 95% CI 1.03-2.66, p = 0.037), chemotherapy at or before SRS (HR = 2.39, 95% CI 1.41-4.05, p = 0.001), WBRT at or before SRS (HR = 2.21, 95% CI 1.16- 4.22, p = 0.017), while surgical resection (HR 0.45, 95% CI 0.21-0. 97, p = 0.04) and immunotherapy (0.34, 95% CI 0.16-0.50, p = 0.014) were associated with lower hazard of local failure. CONCLUSION Factors found to be predictive of local failure included higher RPA score and those receiving chemotherapy, while patients undergoing surgical resection and those with occipital lobe lesions were less likely to experience local failure. Our analyses not only corroborate those previously reported but also demonstrate the utility of a multi-institutional registry to advance real-world SRS research for patients with intracranial metastatic lesions.
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Affiliation(s)
- Anthony L Asher
- Neuroscience Institute, Carolinas Healthcare System and Carolina, Neurosurgery & Spine Associates, Charlotte, NC, 28204, USA
| | - Mohammed Ali Alvi
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
| | - Mohamad Bydon
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55902, USA
| | - Nader Pouratian
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA
| | - Ronald E Warnick
- Department of Neurosurgery, The Jewish Hospital, Cincinnati, OH, USA
| | - James McInerney
- Department of Neurosurgery, Penn State Health, Hershey, PA, USA
| | - Inga S Grills
- Department of Neurological Surgery, Beaumont Health System, Royal Oak, MI, USA
| | - Jason Sheehan
- Department of Neurological Surgery, University of Virginia Health System, 1300 Jefferson Park Ave, Charlottesville, VA, 22908, USA.
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Radwan H, Elserry T, Eisenberg MB, Knisely JPS, Ghaly MM, Schulder M. Subtotal Resection Followed by Adjuvant Radiosurgery for Large Vestibular Schwannomas: Outcomes with Regard to the Timing and Regimen of Irradiation. Acta Neurochir Suppl 2021; 128:1-5. [PMID: 34191056 DOI: 10.1007/978-3-030-69217-9_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To evaluate the results of combined management of large vestibular schwannomas (VS) with initial subtotal resection (STR) followed by adjuvant stereotactic radiosurgery (SRS), with a particular emphasis on the timing and regimen of irradiation. METHODS Seventeen patients underwent STR of a VS followed by SRS, whereas five others were observed after STR. Early SRS (<6 months after surgery) and late SRS (>6 months after surgery) were done in 8 and 9 patients, respectively. Single- and multisession SRS treatments were administered in 10 and 7 patients, respectively. The mean follow-up durations after surgery and SRS were 40 and 28 months, respectively. RESULTS The rates of radiological and oncological tumor control after SRS were 82% and 100%, respectively. The tumor volume at the last follow-up and its relative changes after SRS did not differ significantly on the basis of the irradiation timing (early versus late) or on the basis of the irradiation regimen (single-session versus multisession). In no patient who was observed after STR of a VS was tumor regrowth noted during a mean follow-up period of 49 months. At 12 months after surgery, motor function of the ipsilateral facial nerve corresponded to House-Brackmann grades I, II, III, and IV in 16 patients (73%), 3 patients (14%), 1 patient (5%), and 2 patients (9%), respectively. Facial nerve function at the last follow-up did not differ significantly on the basis of the irradiation timing (early versus late) or on the basis of the irradiation regimen (single-session versus multisession). CONCLUSION The combination of initial STR followed by adjuvant SRS is an effective treatment strategy for patients with a large VS. Although the optimal timing and regimen of postoperative irradiation of the residual lesion should be defined further, our preliminary data suggest that either early or late SRS after surgery may provide good tumor control and optimal functional results.
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Affiliation(s)
- Hesham Radwan
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA.,Department of Neurosurgery, Ain Shams University, Cairo, Egypt
| | - Tarek Elserry
- Department of Neurosurgery, Ain Shams University, Cairo, Egypt
| | - Mark B Eisenberg
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | | | - Maged M Ghaly
- Department of Radiation Medicine, Zucker School of Medicine at Hofstra/Northwell, Lake Success, NY, USA
| | - Michael Schulder
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA. .,Brain Tumor Center, Northwell Neurosciences Insitute, Lake Success, NY, USA.
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Gutierrez-Aceves GA, Rodriguez-Camacho A, Celis-Lopez MA, Moreno-Jimenez S, Herrera-Gonzalez JA. Frameless radiosurgical third ventriculostomy: Technical report. Surg Neurol Int 2020; 11:398. [PMID: 33282458 PMCID: PMC7710479 DOI: 10.25259/sni_247_2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 10/23/2020] [Indexed: 11/28/2022] Open
Abstract
Background: We describe the technical report and results of the first image-guided, linear accelerator, frameless radiosurgical third ventriculostomy. Methods: We report a 20 years old man, with diplopia, balance disturbances, and limitation for gaze supraversion. Magnetic resonance imaging resonance imaging of the brain and cranial computed tomography showed showed a left thalamic-midbrain lesion that caused partial compression of the Silvio aqueduct and mild ventricular dilatation. The biopsy revealed the diagnosis of pleomorphic xanthoastrocytoma. Before radical treatment of the tumor with fractionated stereotactic radiotherapy, the patient underwent to frameless radiosurgical third ventriculostomy, on the TrueBeam STX® platform with the ExacTrac localization system. The target used was the one defined on the floor of the third ventricle, at the midpoint between the mammillary bodies and the infundibular recess. The prescription dose was 120 Gy, given using a monoisocentric technique of multiple noncoplanar circular arches. The geometric arrangement of the plan consisted of 15 arches, with a 4 mm cone, distributed over a 110° table. Results: There was symptomatic and image improvement two days after radiosurgery. On CT, a reduction in ventricular dilation was observed with a reduction in the Evans index from 0.39 (initial CT) to 0.29 (CT at 15 days). In 3.0T magnetic resonance image at 3 months, we showed the third ventriculostomy. There have been no treatment failures or complications. Conclusion: It is possible to effectively perform the frameless radiosurgical third ventriculostomy without associated morbidity in the short term.
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Affiliation(s)
| | - Alejandro Rodriguez-Camacho
- Radio Neurosurgery Unit, National Institute of Neurology and Neurosurgery "Dr. Manuel Velasco Suarez", Mexico City, Mexico
| | - Miguel Angel Celis-Lopez
- Radio Neurosurgery Unit, National Institute of Neurology and Neurosurgery "Dr. Manuel Velasco Suarez", Mexico City, Mexico
| | - Sergio Moreno-Jimenez
- Radio Neurosurgery Unit, National Institute of Neurology and Neurosurgery "Dr. Manuel Velasco Suarez", Mexico City, Mexico
| | - Jose Alfredo Herrera-Gonzalez
- Radio Neurosurgery Unit, National Institute of Neurology and Neurosurgery "Dr. Manuel Velasco Suarez", Mexico City, Mexico
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Boisbouvier S, Tachin C, Lecoeur A, Le Tallec P. [The evolving career profile of radiation therapists]. Cancer Radiother 2020; 24:730-5. [PMID: 32807686 DOI: 10.1016/j.canrad.2020.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 11/21/2022]
Abstract
Over the last few years, the radiation therapist profession has undergone major developments. In radiotherapy, the teams, and their organization as well as the techniques have changed, however always with the goal of improving treatment quality for patients. Throughout interviews, this article offers to show three missions that have been assigned to French radiation therapists, such as the initial consultation, the role of the radiation therapist with the linear accelerator with onboard MRI, and paramedical research. The contribution of new technologies, the modification of the types of participants on the patient journey, as well as the thought process about the use of evidence-based practice and radiation therapist research have initiated changes for the job description, the beginning of more advanced practices, and a perspective of evolution within this profession.
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Yu NY, Sio TT, Lyons MK, Vora SA, Turkmani A, Brown PD, Park SS, Leenstra JL, Bendok BR, Schild SE, Ashman JB. Linear accelerator-based single-fraction stereotactic body radiotherapy for symptomatic vertebral body hemangiomas: The Mayo Clinic experience. J Clin Neurosci 2020; 80:74-78. [PMID: 33099371 DOI: 10.1016/j.jocn.2020.07.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/09/2020] [Accepted: 07/23/2020] [Indexed: 11/27/2022]
Abstract
Symptomatic vertebral hemangiomas (SVHs) are rare benign tumors that when symptomatic require procedural intervention or radiotherapy (RT). Although conventionally-fractionated RT has been an alternative to surgical resection, there is very little data on stereotactic body radiotherapy (SBRT) for SVHs. Six consecutively treated patients with SVHs underwent definitive single-fraction SBRT from 2010 to 2018 at our institution. The RT planning parameters, treatment, outcome, and toxicities are reported for 6 patients with 6 total SVHs treated with single-fraction SBRT. Each patient presented with back pain and received single-fraction SBRT to a thoracic vertebral body hemangioma. One patient had received radiofrequency ablation prior to SBRT. The median SBRT dose was 18 Gy (range, 13-20). Following SBRT, 4 (67%) patients reported improvement in presenting symptoms and 2 patients (33%) were refractory. There were no acute or chronic toxicities associated with SBRT including esophagitis, vertebral compression fractures, or myelopathy. To date, this is the largest series of single-fraction SBRT for SVHs. Single fraction SBRT appears to be a feasible option for SVHs. Further studies are needed to confirm our preliminary findings and optimize dose fractionation.
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Affiliation(s)
- Nathan Y Yu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Terence T Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Mark K Lyons
- Department of Neurological Surgery, Mayo Clinic, Phoenix, AZ, USA
| | - Sujay A Vora
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Ali Turkmani
- Department of Neurological Surgery, Mayo Clinic, Phoenix, AZ, USA
| | - Paul D Brown
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - Sean S Park
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - James L Leenstra
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - Bernard R Bendok
- Department of Neurological Surgery, Mayo Clinic, Phoenix, AZ, USA
| | - Steven E Schild
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
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McClelland S, Lautenschlaeger T, Zang Y, Hanna NH, Shiue K, Kamer AP, Agrawal N, Ellsworth SG, Rhome RM, Watson GA. Radiosurgery dose reduction for brain metastases on immunotherapy (RADREMI): A prospective phase I study protocol. Rep Pract Oncol Radiother 2020; 25:500-506. [PMID: 32477016 DOI: 10.1016/j.rpor.2020.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/10/2020] [Accepted: 04/10/2020] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Up to 20% of patients with brain metastases treated with immune checkpoint inhibitor (ICI) therapy and concomitant stereotactic radiosurgery (SRS) suffer from symptomatic radiation necrosis. The goal of this study is to evaluate Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI) on six-month symptomatic radiation necrosis rates. METHODS This study is a prospective single arm Phase I pilot study which will recruit patients with brain metastases receiving ICI delivered within 30 days before SRS. All patients will be treated with RADREMI dosing, which involves SRS doses of 18 Gy for 0-2 cm lesions, 14 Gy for 2.1-3 cm lesions, and 12 Gy for 3.1-4 cm lesions. All patients will be monitored for six-month symptomatic radiation necrosis (defined as a six-month rate of clinical symptomatology requiring steroid administration and/or operative intervention concomitant with imaging findings consistent with radiation necrosis) and six-month local control. We expect that RADREMI dosing will significantly reduce the symptomatic radiation necrosis rate of concomitant SRS + ICI without significantly sacrificing the local control obtained by the present RTOG 90-05 SRS dosing schema. Local control will be defined according to the Response Assessment in Neuro-Oncology (RANO) criteria. DISCUSSION This study is the first prospective trial to investigate the safety of dose-reduced SRS in treatment of brain metastases with concomitant ICI. The findings should provide fertile soil for future multi-institutional collaborative efficacy trials of RADREMI dosing for this patient population. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT04047602 (registration date: July 25, 2019).
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Affiliation(s)
- Shearwood McClelland
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN 46202, US
| | - Tim Lautenschlaeger
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN 46202, US
| | - Yong Zang
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, IN, US
| | - Nasser H Hanna
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, US
| | - Kevin Shiue
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN 46202, US
| | - Aaron P Kamer
- Department of Radiology, Indiana University School of Medicine, Indianapolis, IN, US
| | - Namita Agrawal
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN 46202, US
| | - Susannah G Ellsworth
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN 46202, US
| | - Ryan M Rhome
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN 46202, US
| | - Gordon A Watson
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN 46202, US
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Daou BJ, Palmateer G, Thompson BG, Maher CO, Hayman JA, Lam KL, Wahl DR, Kim M, Pandey AS. Stereotactic Radiosurgery for Brain Arteriovenous Malformations: Evaluation of Obliteration and Review of Associated Predictors. J Stroke Cerebrovasc Dis 2020; 29:104863. [PMID: 32689634 DOI: 10.1016/j.jstrokecerebrovasdis.2020.104863] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/11/2020] [Accepted: 04/02/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND High arteriovenous malformation (AVM) obliteration rates have been reported with stereotactic radiosurgery (SRS), and multiple factors have been found to be associated with AVM obliteration. These predictors have been inconsistent throughout studies. We aimed to analyze our experience with linear accelerator (LINAC)-based SRS for brain AVMs, evaluate outcomes, assess factors associated with AVM obliteration and review the various reported predictors of AVM obliteration. METHODS Electronic medical records were retrospectively reviewed to identify consecutive patients with brain AVMs treated with SRS over a 27-year period with at least 2 years of follow-up. Logistic regression analysis was performed to identify factors associated with AVM obliteration. RESULTS One hundred twenty-eight patients with 142 brain AVMs treated with SRS were included. Mean age was 34.4 years. Fifty-two percent of AVMs were associated with a hemorrhage before SRS, and 14.8% were previously embolized. Mean clinical and angiographic follow-up times were 67.8 months and 58.6 months, respectively. The median Spetzler-Martin grade was 3. Mean maximal AVM diameter was 2.8 cm and mean AVM target volume was 7.4 cm3 with a median radiation dose of 16 Gy. Complete AVM obliteration was achieved in 80.3%. Radiation-related signs and symptoms were encountered in 32.4%, only 4.9% of which consisted of a permanent deficit. Post-SRS AVM-related hemorrhage occurred in 6.3% of cases. In multivariate analysis, factors associated with AVM obliteration included younger patient age (P = .019), male gender (P = .008), smaller AVM diameter (P = .04), smaller AVM target volume (P = .009), smaller isodose surface volume (P = .005), a higher delivered radiation dose (P = .013), and having only one major draining vein (P = .04). CONCLUSIONS AVM obliteration with LINAC-based radiosurgery was safe and effective and achieved complete AVM obliteration in about 80% of cases. The most prominent predictors of AVM success included AVM size, AVM volume, radiation dose, number of draining veins and patient age.
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Affiliation(s)
- Badih J Daou
- Departments of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
| | - Gregory Palmateer
- Departments of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
| | - B Gregory Thompson
- Departments of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
| | - Cormac O Maher
- Departments of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
| | - James A Hayman
- Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
| | - Kwok L Lam
- Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
| | - Daniel R Wahl
- Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
| | - Michelle Kim
- Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
| | - Aditya S Pandey
- Departments of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
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Zhang M, Fan Q, Lei Y, Thapa B, Padula G. Assessment of an Elekta Versa HD linear accelerator for stereotactic radiosurgery with circular cone collimators. J Xray Sci Technol 2020; 28:71-82. [PMID: 31904001 DOI: 10.3233/xst-190580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
BACKGROUND Versa HD linear accelerators (linacs) are used for stereotactic radiosurgery treatment. However, the mechanical accuracy of such systems remains a concern. OBJECTIVE The purpose of this study was to evaluate the accuracy of an Elekta Versa HD linac. METHODS We performed measurements with a ball bearing phantom to calculate the rotational isocenter radii of the linac's gantry, collimator, and table, and determine the relative locations of those isocenters. We evaluated the accuracy of the cone-beam computed tomography (CBCT) guidance with a film-embedding head phantom and circular cone-collimated radiation beams. We also performed dosimetric simulations to study the effects of the linac mechanical uncertainties on non-coplanar cone arc delivery. RESULTS The mechanical uncertainty of the linac gantry rotation was 0.78 mm in radius, whereas that of the collimator and the table was <0.1 mm and 0.33 mm, respectively. The axes of rotation of the collimator and the table were coinciding with and 0.13 mm away from the gantry isocenter, respectively. Experiments with test plans demonstrated the limited dosimetric consequences on the circular arc delivery given the aforementioned mechanical uncertainties. End-to-end measurements determined that the uncertainty of the CBCT guidance was≤1 mm in each direction with respect to the reference CT image. CONCLUSIONS In arc delivery, the mechanical uncertainties associated with the gantry and the table do not require remarkable increases in geometric margins. If large enough, the residual setup errors following CBCT guidance will dominate the overall dosimetric consequence. Therefore, the Versa HD linac is a valid system for stereotactic radiosurgery using non-coplanar arc delivery.
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Affiliation(s)
- Mutian Zhang
- Radiation Therapy, Summa Health Cancer Institute, Akron, Ohio, USA
| | - Qiyong Fan
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Yu Lei
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Bishnu Thapa
- Radiation Therapy, Summa Health Cancer Institute, Akron, Ohio, USA
| | - Gilbert Padula
- Radiation Therapy, Summa Health Cancer Institute, Akron, Ohio, USA
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Biltekin F, Yedekci Y, Ozyigit G. Feasibility of novel in vivo EPID dosimetry system for linear accelerator quality control tests. Australas Phys Eng Sci Med 2019; 42:995-1009. [PMID: 31515686 DOI: 10.1007/s13246-019-00798-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/04/2019] [Indexed: 11/26/2022]
Abstract
The main aim was to validate the capability of a novel EPID-based in vivo dosimetry system for machine-specific quality control (QC) tests. In current study, two sets of measurements were performed in Elekta Versa HD linear accelerator using novel iViewDose™ in vivo dosimetry software. In the first part, measurements were carried out to evaluate the feasibility of novel in vivo system for daily dosimetric QC tests including output constancy, percentage depth dose (PDD) and beam profile measurements. In addition to daily QC tests, measured output factor as a function of field size, leaf transmission and tongue and groove effect were compared with calculated TPS data. In the second part of the measurements, detection capability of iViewDose software for basic mechanical QC tests were investigated for different setup conditions. In dosimetric QC tests, measured output factor with changing field size, PDD, beam profile and leaf transmission factors were found to be compatible with calculated TPS data. Additionally, the EPID-based system was capable to detect given dose calibration errors of 1% with ± 0.02% deviation. In mechanical QC tests, it was found that iViewDose software was sensitive for catching errors in collimator rotation (≥ 1°), changes in phantom thickness (≥ 1 cm) and major differences in irradiated field size down to 1 mm. In conclusion, iViewDose was proved to be as useful EPID-based software for daily monitoring of linear accelerator beam parameters and it provides extra safety net to prevent machine based radiation incidents.
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Affiliation(s)
- Fatih Biltekin
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey.
| | - Yagiz Yedekci
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
| | - Gokhan Ozyigit
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
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McClelland S, Degnin C, Chen Y, Watson GA, Jaboin JJ. Impact of the American Tax Payer Relief Act on stereotactic radiosurgery utilization in the United States. J Neurooncol 2019; 145:159-165. [PMID: 31485922 DOI: 10.1007/s11060-019-03283-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 08/29/2019] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Single-fraction stereotactic radiosurgery (SRS) is delivered predominantly via two modalities: Gamma Knife, and linear accelerator (LINAC). Implementation of the American Tax Payer Relief Act (ATRA) in 2013 represented the first time limitations specifically targeting SRS reimbursement were introduced into federal law. The subsequent impact of the ATRA on SRS utilization in the United States (US) has yet to be examined. METHODS The National Cancer Database from 2010-2016 identified brain metastases patients from non-small cell lung cancer throughout the US having undergone SRS. Utilization between GKRS and LINAC was assessed before (2010-2012), during (2013-2014) and after (2015-2016) ATRA implementation. RESULTS In 2013, there was a substantial decrease of LINAC SRS in favor of GKRS in non-academic centers. Over the 3-year span immediately preceding ATRA implementation, 39% of all eligible SRS cases received LINAC. There was a modest decrease in LINAC utilization over the 2 years immediately following ATRA implementation (35%), followed by an increase over the next two years (40%). SRS modality showed differences over the three time periods (unadjusted, p = 0.043), primarily in non-academic centers (unadjusted, p = 0.003). CONCLUSIONS ATRA implementation in 2013 caused an initial spike in Gamma Knife SRS utilization, followed by a decline to rates similar to the years before implementation. These findings indicate that the ATRA provision mandating Medicare reduction of outpatient payment rates for Gamma Knife to be equivalent with those of LINAC SRS had a significant short-term impact on the radiosurgical treatment of metastatic brain disease throughout the US, serving as a reminder of the importance/impact of public policy on treatment modality utilization by physicians and hospitals.
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Affiliation(s)
- Shearwood McClelland
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN, 46202, USA.
| | - Catherine Degnin
- Biostatistics Shared Resource, Oregon Health and Science University, Portland, OR, USA
| | - Yiyi Chen
- Biostatistics Shared Resource, Oregon Health and Science University, Portland, OR, USA
| | - Gordon A Watson
- Department of Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, IN, 46202, USA
| | - Jerry J Jaboin
- Department of Radiation Medicine, Oregon Health and Science University, Portland, OR, USA
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Giraud P, Kreps S, Tournat H, Bibault JE, Fabiano E, Feutren T, Dautruche A, Durdux C. [Stereotactic pulmonary radiotherapy: Which machine?]. Cancer Radiother 2019; 23:658-661. [PMID: 31471252 DOI: 10.1016/j.canrad.2019.07.126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 07/03/2019] [Indexed: 11/29/2022]
Abstract
Stereotactic radiotherapy represents a fundamental change in the practice of radiotherapy of lung cancers. Despite the great heterogeneity of sites, techniques, and doses, most studies found a high local control rate, around 70 to 90% at 2 years, and reduced toxicity, around 5% of grade 3 at 2 years. Stereotactic radiotherapy can be realized either by a dedicated accelerator (CyberKnife®) or by a conventional accelerator associated with specific systems. The two modalities deliver a very precise irradiation whose very good results published to date are similar. Some technical characteristics specific to each type of linear accelerator could guide the choice according to the target volume treated.
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Affiliation(s)
- P Giraud
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France.
| | - S Kreps
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France
| | - H Tournat
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France
| | - J-E Bibault
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France
| | - E Fabiano
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France
| | - T Feutren
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France
| | - A Dautruche
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France
| | - C Durdux
- Service d'oncologie radiothérapie, hôpital européen Georges-Pompidou, 20, rue Leblanc, 75015 Paris, France; Université Paris-Descartes, 75006 Paris, France
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Riou O, Valdenaire S, Debuire P, Fenoglietto P, Debrigode C, Mazard T, Assenat É, Aillères N, Azria D. [Liver stereotactic body radiotherapy: Clinical features and technical consequences, results. Which treatment machine in which situation?]. Cancer Radiother 2019; 23:636-50. [PMID: 31444078 DOI: 10.1016/j.canrad.2019.07.159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/05/2019] [Accepted: 07/05/2019] [Indexed: 12/31/2022]
Abstract
Liver stereotactic body radiotherapy is a developing technique for the treatment of primary tumours and metastases. Its implementation is complex because of the particularities of the treated organ and the comorbidities of the patients. However, this technique is a treatment opportunity for patients otherwise in therapeutic impasse. The scientific evidence of liver stereotactic body radiotherapy has been considered by the French health authority as insufficient for its widespread use outside specialized and experienced centers, despite a growing and important number of retrospective and prospective studies, but few comparative data. This article focuses on the specific features of stereotactic body radiotherapy for liver treatments and the results of published studies of liver stereotactic body radiotherapy performed with classic linear accelerators and dedicated radiosurgery units.
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Rijken J, Bhat M, Crowe S, Trapp J. Conservatism in linear accelerator bunker shielding. Australas Phys Eng Sci Med 2019; 42:781-787. [PMID: 31346964 DOI: 10.1007/s13246-019-00782-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/18/2019] [Indexed: 10/26/2022]
Abstract
Conservatism in the shielding of linear accelerator bunkers is engrained in the methodology of international protocols and guidelines. However, the degree to which this cautious and prudent approach is necessary should be judged against the International Committee of Radiation Protection's principles of exposure justification and optimisation. Radiation survey data from 75 concrete barriers was aggregated and compared to exposure predictions from three popular protocols in order to assess any conservatism in factors used to calculate scatter, leakage and beam penetration. These findings, in addition to a list of common conservative practices, were then used to tally the possible fiscal impact of an over-conservative approach to linear accelerator bunker shielding. While primary beam penetration was accurately predicted, stated conservatisms in scatter and leakage was found to be largely misplaced. An estimated total factor of conservatism calculated from a tally was found to be in agreement with literature values of radiotherapist occupational exposure. This factor amounted to a cost increase of 43% for a single bunker if all conservative assumptions were made. There are aspects of linear accelerator shielding design that have been shown to be overly conservative, beyond what is justifiable by the International Committee of Radiation Protection. Some adjustment to international protocol methodology may be required.
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Affiliation(s)
- James Rijken
- GenesisCare, St Andrew's Hospital, Adelaide, SA, Australia. .,Queensland University of Technology, Brisbane, QLD, Australia.
| | - Madhava Bhat
- GenesisCare, St Andrew's Hospital, Adelaide, SA, Australia
| | - Scott Crowe
- Queensland University of Technology, Brisbane, QLD, Australia.,Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Jamie Trapp
- Queensland University of Technology, Brisbane, QLD, Australia
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Kandlakunta P, Momin S, Sloop A, Zhang T, Khan R. Characterizing a Geant4 Monte Carlo model of a multileaf collimator for a TrueBeam™ linear accelerator. Phys Med 2019; 59:1-12. [PMID: 30928056 DOI: 10.1016/j.ejmp.2019.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/11/2019] [Accepted: 02/12/2019] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The purpose of this work was to develop and validate a multileaf collimator (MLC) model for a TrueBeam™ linac using Geant4 Monte Carlo (MC) simulation kit. METHODS A Geant4 application was developed to accurately represent TrueBeam™ linac. Pre-computed phase-space file in a plane just above the jaws was used for radiation transport. A Varian 120 leaf Millennium™ MLC was modeled using geometry and material specifications provided by the manufacturer using Geant4 constructs. Leaf characteristics e.g. tongue-groove design, variable thickness, interleaf gap were simulated. The linac model was validated by comparing simulated dose profiles and depth-doses with experimental data using an ionization chamber in water. Dosimetric characteristics of the MLC such as inter- and intra-leaf leakage, penumbra effect, MLC leaf positioning, and dynamic characteristics were also investigated. RESULTS For the depth dose curves, 99% of the calculated data points agree within 1% of the experimental values for the 4 × 4 cm2 and 10 × 10 cm2 and within 2% of the experimental values for 20 × 20, 30 × 30 and 40 × 40 cm2 jaw defined fields. The cross-plane dose profiles show agreement <2% for depths up to 10 cm and to within 4% beyond 10 cm. MLC dosimetric characterization with MC agree well with film measurements. The rounded leaf penumbra remained constant throughout the range of leaf motion. CONCLUSIONS The TrueBeam™ linac equipped with 120-leaf MLC was successfully modeled using Geant4. The accuracy of the model was verified by comparing the simulations with experiments. The model may be utilized for independent dose verification and QA of IMRT.
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Affiliation(s)
- Praneeth Kandlakunta
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Shadab Momin
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Austin Sloop
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Tiezhi Zhang
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA
| | - Rao Khan
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St Louis, MO, USA.
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Ros-Sanjuán Á, Iglesias-Moroño S, Troya-Castilla M, Márquez-Márquez B, Herruzo-Cabrera I, Arráez-Sánchez MÁ. LINAC radiosurgery treatment for vestibular schwannoma. Neurocirugia (Astur) 2019; 30:179-187. [PMID: 30770322 DOI: 10.1016/j.neucir.2018.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 12/15/2018] [Accepted: 12/21/2018] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The aims of our study were to evaluate tumour response in a series of patients with vestibular schwannoma (VS) treated with linear accelerator stereotactic radiosurgery (LINAC-RS), to describe the complications and to analyze the variables associated with the response to treatment. MATERIAL AND METHODS This retrospective descriptive study included 64 patients treated from 2010 to 2016 with a minimum follow-up of one year, excluding patients with neurofibromatosis. Clinical-radiological parameters were evaluated. The treatment was performed using LINAC-RS. The prescribed dose was 12Gy at 90% isodose. RESULTS The mean age at treatment was 53 years, 56% were women. Ninety-eight percent of the patients had hearing loss, 71% with grade III according to the Gardner-Robertson Classification. The mean volume at treatment was 2.92cc and the mean follow-up, 40.95 months. The overall therapeutic success was 90%, reaching 100% at 12 and 24 months, and 86% after 36 months of follow-up. The radiological result was significantly related to the initial tumour volume (p<0.037). In 20 patients there was evidence of transient tumour growth compatible with pseudoprogression. Acute complications were present in 37.5%, and transitory complications in 50%. Chronic complications were found in 20%, with 84% being permanent. The rate of acute complications was lower in patients with regression (p<0.016). Chronic complications were more frequent in the 41-60 year old age group (p<0.040). CONCLUSIONS In our study, the overall tumour control was in accordance with other published series. The radiological result significantly related to the tumour volume at the commencement of treatment. The rate of acute complications was lower in patients with regression.
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Affiliation(s)
- Ángela Ros-Sanjuán
- Department of Neurosurgery, Regional University Hospital of Malaga, Malaga, Spain.
| | - Sara Iglesias-Moroño
- Department of Neurosurgery, Regional University Hospital of Malaga, Malaga, Spain
| | - Marta Troya-Castilla
- Department of Neurosurgery, Regional University Hospital of Malaga, Malaga, Spain
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Abstract
Background PRIMO is a dose verification system based on the general-purpose Monte Carlo radiation transport code penelope, which implements an accurate physics model of the interaction cross sections and the radiation transport process but with low computational efficiency as compared with fast Monte Carlo codes. One of these fast Monte Carlo codes is the Dose Planning Method (DPM). The purpose of this work is to describe the adaptation of DPM as an alternative PRIMO computation engine, to validate its performance against penelope and to validate it for some specific cases. Methods DPM was parallelized and modified to perform radiation transport in quadric geometries, which are used to describe linacs, thus allowing the simulation of dynamic treatments. To benchmark the new code versus penelope, both in terms of accuracy of results and simulation time, several tests were performed, namely, irradiation of a multi-layer phantom, irradiation of a water phantom using a collimating pattern defined by the multileaf collimator (MLC), and four clinical cases. The gamma index, with passing criteria of 1 mm/1%, was used to compare the absorbed dose distributions. Clinical cases were compared using a 3-D gamma analysis. Results The percentage of voxels passing the gamma criteria always exceeded 99% for the phantom cases, with the exception of the transport through air, for which dose differences between DPM and penelope were as large as 24%. The corresponding percentage for the clinical cases was larger than 99%. The speedup factor between DPM and penelope ranged from 2.5 ×, for the simulation of the radiation transport through a MLC and the subsequent dose estimation in a water phantom, up to 11.8 × for a lung treatment. A further increase of the computational speed, up to 25 ×, can be obtained in the clinical cases when a voxel size of (2.5 mm)3 is used. Conclusions DPM has been incorporated as an efficient and accurate Monte Carlo engine for dose estimation in PRIMO. It allows the concatenated simulation of the patient-dependent part of the linac and the patient geometry in static and dynamic treatments. The discrepancy observed between DPM and penelope, which is due to an artifact of the cross section interpolation algorithm for low energy electrons in air, does not affect the results in other materials.
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Affiliation(s)
- Miguel Rodriguez
- Centro Médico Paitilla, Calle 53 y ave. Balboa, Panama City, Panama.,Instituto de Investigaciones Científicas y de Alta Tecnología, INDICASAT-AIP, City of Knowledge, Building 219, Panama City, Panama
| | - Josep Sempau
- Universitat Politècnica de Catalunya, Diagonal 647, Barcelona, E-08028, Spain
| | - Christian Bäumer
- West German Proton Therapy Centre Essen (WPE), Hufelandstraße 55, Essen, D-45147, Germany.,West German Cancer Center (WTZ), Hufelandstraße 55, Essen, D-45147, Germany.,University Hospital Essen, Hufelandstraße 55, Essen, D-45147, Germany.,German Cancer Consortium (DKTK), Hufelandstraße 55, Essen, D-45147, Germany
| | - Beate Timmermann
- West German Proton Therapy Centre Essen (WPE), Hufelandstraße 55, Essen, D-45147, Germany.,West German Cancer Center (WTZ), Hufelandstraße 55, Essen, D-45147, Germany.,University Hospital Essen, Hufelandstraße 55, Essen, D-45147, Germany.,German Cancer Consortium (DKTK), Hufelandstraße 55, Essen, D-45147, Germany.,Department of Particle Therapy, University Hospital Essen, Hufelandstraße 55, Essen, D-45147, Germany
| | - Lorenzo Brualla
- West German Proton Therapy Centre Essen (WPE), Hufelandstraße 55, Essen, D-45147, Germany. .,West German Cancer Center (WTZ), Hufelandstraße 55, Essen, D-45147, Germany. .,University Hospital Essen, Hufelandstraße 55, Essen, D-45147, Germany.
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Velnar T, Bosnjak R. Radiosurgical techniques for the treatment of brain neoplasms: A short review. World J Methodol 2018; 8:51-58. [PMID: 30596035 PMCID: PMC6305523 DOI: 10.5662/wjm.v8.i4.51] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/06/2018] [Accepted: 11/16/2018] [Indexed: 02/06/2023] Open
Abstract
Radiotherapy has long been used as an adjunct to neurosurgery for the treatment of malignant and benign intracranial tumors and other intracranial lesions. Intracranial tumors can be irradiated in three different ways: I) fractional radiotherapy, II) stereotactic radiotherapy and III) stereotactic radiosurgery. The third is most often by means of a gamma knife or a specially designed linear accelerator. Additionally, radiosurgery is increasingly used in combination with systemic therapy to treat metastases.
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Affiliation(s)
- Tomaz Velnar
- Department of Neurosurgery, University Medical Centre Ljubljana, Ljubljana 1000, Slovenia
- AMEU-ECM, Maribor 2000, Slovenia
| | - Roman Bosnjak
- Department of Neurosurgery, University Medical Centre Ljubljana, Ljubljana 1000, Slovenia
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Fenlon JB, Khattab MH, Ferguson DC, Luo G, Keedy VL, Chambless LB, Kirschner AN. Linear Accelerator-Based Stereotactic Radiosurgery for Cranial Intraparenchymal Metastasis of a Malignant Peripheral Nerve Sheath Tumor: Case Report and Review of the Literature. World Neurosurg 2018; 123:123-127. [PMID: 30529515 DOI: 10.1016/j.wneu.2018.11.231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/28/2018] [Indexed: 01/18/2023]
Abstract
BACKGROUND Malignant peripheral nerve sheath tumors (MPNSTs) are rare, aggressive soft tissue sarcomas. MPNST intracranial metastasis is exceedingly rare with only 22 documented cases in the literature and, to our knowledge, only 1 case with intraparenchymal brain metastasis. Most have been managed surgically; however, 2 documented cases were treated with Gamma Knife radiosurgery. Excluding this case report, there are no other documented cases of linear accelerator-based stereotactic radiosurgery (SRS) to treat MPNST brain metastasis. CASE DESCRIPTION A 41-year-old man with MPNST of the lung initially underwent tumor resection. He developed multiple systemic metastases that were managed with directed radiation therapy. A parietal brain metastasis was treated with linear accelerator-based SRS. Following SRS therapy, the patient was treated with a tropomyosin receptor kinase inhibitor. Complete resolution of brain metastasis was seen on brain magnetic resonance imaging 5 months after treatment with SRS. At 11 months after SRS, there was no evidence of recurrence or progression of the intraparenchymal disease. The patient continued to have stable extracranial disease on his ninth cycle of systemic treatment. CONCLUSIONS This report provides important insights into efficacy of linear accelerator-based SRS to treat MPNST brain metastases.
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Affiliation(s)
- Jordan B Fenlon
- Western Michigan University School of Medicine, Kalamazoo, Michigan, USA
| | - Mohamed H Khattab
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Donna C Ferguson
- Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Guozhen Luo
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Vicki L Keedy
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lola B Chambless
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Austin N Kirschner
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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Moghadam SE, Nasseri S, Seyedi SS, Gholamhosseinian H, Momennezhad M. Evaluation of application of EPID for rapid QC testing of linear accelerator. Rep Pract Oncol Radiother 2018; 23:369-377. [PMID: 30127677 DOI: 10.1016/j.rpor.2018.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 05/15/2018] [Accepted: 07/21/2018] [Indexed: 10/28/2022] Open
Abstract
Aim Evaluation of application of EPID for rapid QC testing of linear accelerator. Background Quality control of a linear accelerator device is a time and energy intensive process. In this study, attempts have been made to perform the linear accelerator quality control using electronic portal imaging device (EPID), which is mounted on most accelerators. Materials and methods First, quality control and dosimetry parameters of the device were determined and measured based on standard protocols to ensure full calibration of the accelerator. Then, various features of EPID including spatial resolution and contrast resolution, the effect of buildup region, dose response and image uniformity were evaluated. In the next step, consistent with the parameters of linear accelerator quality control including field size, field flatness and symmetry, the light field coincidence with X-ray field, mechanical stability and multileaf collimator position accuracy test, the output images of device were obtained.After feeding images to the MATLAB software, their pixel content was analyzed. All measurements of the three photon beams were repeated three times. Results The EPID image had a desirable resolution, contrast and uniformity and displayed high sensitivity to dose changes with linear dose response. Seven qualitative parameters of the linear accelerator were then controlled by EPID. Conclusions The results of the linear accelerator quality control using the EPID were consistent with practice. Quality control using the EPID was more convenient and faster than conventional methods.
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Affiliation(s)
- Shahla Ebrahimi Moghadam
- Department of Medical Physics, Faculty of Medicine, Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Shahrokh Nasseri
- Department of Medical Physics, Faculty of Medicine, Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Seyedeh Somayeh Seyedi
- Department of Medical Physics, Faculty of Medicine, Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamid Gholamhosseinian
- Department of Medical Physics, Faculty of Medicine, Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mehdi Momennezhad
- Department of Medical Physics, Faculty of Medicine, Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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Rashid A, Pintea B, Kinfe TM, Surber G, Hamm K, Boström JP. LINAC stereotactic radiosurgery for trigeminal neuralgia -retrospective two-institutional examination of treatment outcomes. Radiat Oncol 2018; 13:153. [PMID: 30134992 PMCID: PMC6106738 DOI: 10.1186/s13014-018-1102-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 08/16/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In this pooled 2-center series LINAC radiosurgery (SRS) has been applied as a treatment option for a subset of refractory trigeminal neuralgia (TN) patients. This study approached to retrospectively assess the efficacy and safety of LINAC SRS and to provide a brief overview addressed to the technical development from frame-based towards frameless robotic SRS. METHODS From 2001 to 2017 n = 55 patients (pts) were treated, n = 28 were female (51%), mean age: 66 years (range 36-93 years); TN etiology: 37 classic TN, 15 multiple sclerosis (MS)-related TN, 2 symptomatic TN, and 1 atypical TN. Previous treatment was present in n = 35 (63.6%) pts. (some multiple or combined) with n = 23 microsurgical vascular decompression and n = 17 percutaneous retrogasserian rhizotomy. A 6 MV LINAC (4-5 mm collimators) was applied in all pts. (n = 26 framebased - n = 29 frameless robotic). The dorsal root entry zone (DREZ) was targeted in n = 35 cases and the retrogasserian target in n = 20 pts. with a homogeneous dose for the entire study cohort (90 Gy). SRS outcome was measured using the Barrow Neurological Institute (BNI) score for pain and hypaesthesia and statistically evaluated by univariate and multivariate analyzes. RESULTS Mean follow-up (FU) was 30 months (2 lost FU); the total rate of post SRS BNI pain I-IIIa (=painfree w or w/o medication) was 69% (88% for the classic TN pts), 29% (38.8% classic TN) were classified as BNI pain I-II (=painfree w/o medication). A BNI hypaesthesia II-III was present in 9.4% (n = 5) and BNI hypaesthesia IV in n = 2. Between groups analysis demonstrated no correlation of SRS responsiveness with age, gender, MS- or not MS-associated TN, previous surgery, framebased/frameless robotic SRS. DREZ targeting significantly better suppressed TN compared to RG targeting (p = 0.01). Additionally, a statistical trend for a better BNI pain outcome (p = 0.07) along with a significant increase in BNI hypaesthesia (p = 0.01) was found when using a larger partial trigeminal 70 Gy volume. CONCLUSION Our retrospective analysis support LINAC SRS as an effective and safe treatment option in TN. Frameless robotic SRS of TN is safe when using a dedicated LINAC system. A target definition closer to the brainstem and tendencially a larger target volume were associated with a better outcome for pain.
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Affiliation(s)
- Ali Rashid
- Department of Radiosurgery and Stereotactic Radiotherapy, MediClin Robert Janker Clinic and MediClin MVZ Bonn, Villenstrasse 8, 53129, Bonn, Germany
| | - Bogdan Pintea
- Department of Neurosurgery, BG University Hospital Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Thomas M Kinfe
- Department of Psychiatry, Division of Medical Psychology, University Hospital of Bonn, Sigmund-Freud-Strasse 25, 53105, Bonn, Germany
| | - Gunnar Surber
- CyberKnife Zentrum Mitteldeutschland, Nordhäuser Strasse 74, 99089, Erfurt, Germany
| | - Klaus Hamm
- CyberKnife Zentrum Mitteldeutschland, Nordhäuser Strasse 74, 99089, Erfurt, Germany
| | - Jan P Boström
- Department of Radiosurgery and Stereotactic Radiotherapy, MediClin Robert Janker Clinic and MediClin MVZ Bonn, Villenstrasse 8, 53129, Bonn, Germany. .,Department of Neurosurgery, University of Bonn Medical Center, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Sarkar B. In regard to "Tran A, Zhang J, Woods K, Yu V, Nguyen D, Gustafson G, Rosen L, Sheng K. Treatment planning comparison of IMPT, VMAT and 4π radiotherapy for prostate cases. Radiation oncology. 2017 Jan 11; 12(1):10". Radiat Oncol 2018; 13:63. [PMID: 29650027 PMCID: PMC5896086 DOI: 10.1186/s13014-018-1009-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/22/2018] [Indexed: 11/21/2022] Open
Abstract
This article describe the three dimensional geometrical incompetency of the term "4π radiotherapy"; frequently used in radiation oncology to establish the superiority (or rather complexity) of particular kind of external beam delivery technique. It was claimed by several researchers, to obtain 4πc solid angle at target centre created by the tele-therapy delivery machine in three dimensional Euclidian space. However with the present design of linear accelerator (or any other tele-therapy machine) it is not possible to achieve more than 2πc with the allowed boundary condition of 0 ≤ Gnatry position≤πc and [Formula: see text]≤Couch Position≤[Formula: see text] .This article describes why it is not possible to achieve a 4πc solid angle at any point in three dimensional Euclidian spaces. This article also recommends not to use the terminology "4π radiotherapy" for describing any external beam technique or its complexity as this term is geometrically wrong.
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Affiliation(s)
- Biplab Sarkar
- Department of radiation Oncology, Fortis Memorial Research Institute, Gurgaon, India.
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Ben Salem L, Essadok A, Saidani I, Mahdouani M, Benna M, Mahjoubi K, Besbes M, Benna F. [Experimental determination of correction factors of four detectors used in small field radiotherapy]. Cancer Radiother 2018; 22:45-51. [PMID: 29290555 DOI: 10.1016/j.canrad.2017.08.110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 07/22/2017] [Accepted: 08/02/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE The aim of this work is to determine experimentally the correction factors [Formula: see text] for four active commercial dosimeters: two microchambers and two diode detectors based on the output factor measured with radiochromic film for a radiotherapy linear accelerator equipped with circular cones. MATERIALS AND METHODS Initially, a radiochromic film dosimetry measurement protocol with an accuracy of 2% was developed to approach the "reference output factor". Afterwards, the corrective factors of four detectors were determined for two ionization chambers (PinPoint PTW 31016 3D, Micropoint Extradin A16) and two diodes (PTW T60017 Diode, PTW-60019 Micro-Diamond). These measurements were carried out under conical BrainLAB® collimators defining circular fields with diameters equal to 7.5mm, 10mm, 12.5mm, 15mm, 17.5mm, 20mm, 25mm, 30mm, 35mm and 45mm of a 6MV X-ray beam generated by the ClinaciX linear accelerator (Varian®). These factors are weakly dependent on the type of accelerator, whether the model and the collimation type. This allowed their comparisons with those published for the same type of detector and for an accelerator with the same index of beam quality. RESULTS The correction factors obtained experimentally were comparable in maximum deviation of 1.9% with published ones of the works using the same type of detector (mark and model) and an accelerator delivering the same beam quality for the same field size at the measurement point. CONCLUSION The measurement protocol using the EBT3 film, which was used as a passive dosimeter to determine the "reference output factor", was validated by comparing measured and published data of active detector correction factors.
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Affiliation(s)
- L Ben Salem
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie.
| | - A Essadok
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie
| | - I Saidani
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie
| | - M Mahdouani
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie
| | - M Benna
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie
| | - K Mahjoubi
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie
| | - M Besbes
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie
| | - F Benna
- Unité de radiophysique, service de radiothérapie, institut Salah-Azaiz de Tunis, boulevard 9-Avril, 1006 Tunis, Tunisie
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