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Pace M, Bonanno E, Borzì GR, Cavalli N, D'Anna A, Gueli AM, Stella G, Zirone L, Marino C. Organ dose in CT: Comparison between measurements and computational methods. Phys Med 2023; 112:102627. [PMID: 37348452 DOI: 10.1016/j.ejmp.2023.102627] [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: 04/29/2022] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/24/2023] Open
Abstract
PURPOSE This study aims to compare two methods for the organ dose evaluation in computed tomography (CT) in the head- and thorax regions: an experimental method, using radiochromic films, and a computational one, using a commercial software. METHODS Gafchromic® XR-QA2 and EBT-3 were characterized in terms of energetic, angular, and irradiation configurations dependence. Two free-in-air irradiation calibration configurations were employed using a CT scanner: with the sensitive surface of the film orthogonal (OC) and parallel (PC) to the beam axis. Different dose-response curves were obtained by varying the irradiation configurations and the beam quality (BQ). Subsequently, films were irradiated within an anthropomorphic phantom using CT-thorax and -head protocols, and the organ dose values obtained were compared with those provided by the commercial software. RESULTS At different configurations, an unchanged dose response was achieved with EBT-3, while a dose response of 15% was obtained with XR-QA2. By varying BQ, XR-QA2 showed a different response below 10%, while EBT-3 showed a variation below 5% for dose values >20 mGy. For films irradiation angle equal to 90°, the normalized to 0° relative response was 41% for the XR-QA2 model and 83% for the EBT-3 one. Organ dose values obtained with EBT-3 for both configurations and with XR-QA2 for OC were in agreement with the DW values, showing percentage discrepancies of less than 25%. CONCLUSIONS The obtained results showed the potential of EBT-3 in CT patient dosimetry since the lower angular dependence, compared to XR-QA2, compensates for low sensitivity in the diagnostic dose range.
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Affiliation(s)
- Martina Pace
- Medical Physics Department, Humanitas Istituto Clinico Catanese, Misterbianco, CT, Italy
| | - Elisa Bonanno
- Medical Physics Department, Humanitas Istituto Clinico Catanese, Misterbianco, CT, Italy
| | - Giuseppina Rita Borzì
- Medical Physics Department, Humanitas Istituto Clinico Catanese, Misterbianco, CT, Italy
| | - Nina Cavalli
- Medical Physics Department, Humanitas Istituto Clinico Catanese, Misterbianco, CT, Italy
| | - Alessia D'Anna
- Department of Physics and Astronomy E. Majorana, University of Catania, Catania, Italy
| | - Anna Maria Gueli
- Department of Physics and Astronomy E. Majorana, University of Catania, Catania, Italy
| | - Giuseppe Stella
- Department of Physics and Astronomy E. Majorana, University of Catania, Catania, Italy.
| | - Lucia Zirone
- Medical Physics Department, Humanitas Istituto Clinico Catanese, Misterbianco, CT, Italy; Department of Physics and Astronomy E. Majorana, University of Catania, Catania, Italy
| | - Camelo Marino
- Medical Physics Department, Humanitas Istituto Clinico Catanese, Misterbianco, CT, Italy
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Zirone L, Bonanno E, Borzì GR, Cavalli N, D’Anna A, Galvagno R, Girlando A, Gueli AM, Pace M, Stella G, Marino C. HyperArc TM Dosimetric Validation for Multiple Targets Using Ionization Chamber and RT-100 Polymer Gel. Gels 2022; 8:gels8080481. [PMID: 36005082 PMCID: PMC9407338 DOI: 10.3390/gels8080481] [Citation(s) in RCA: 2] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/25/2022] [Accepted: 07/28/2022] [Indexed: 11/16/2022] Open
Abstract
Multiple brain metastases single-isocenter stereotactic radiosurgery (SRS) treatment is increasingly employed in radiotherapy department. Before its use in clinical routine, it is recommended to perform end-to-end tests. In this work, we report the results of five HyperArcTM treatment plans obtained by both ionization chamber (IC) and polymer gel. The end-to-end tests were performed using a water equivalent Mobius Verification PhantomTM (MVP) and a 3D-printed anthropomorphic head phantom PseudoPatient® (PP) (RTsafe P.C., Athens, Greece); 2D and 3D dose distributions were evaluated on the PP phantom using polymer gel (RTsafe). Gels were read by 1.5T magnetic resonance imaging (MRI). Comparison between calculated and measured distributions was performed using gamma index passing rate evaluation by different criteria (5% 2 mm, 3% 2 mm, 5% 1 mm). Mean point dose differences of 1.01% [min −0.77%−max 2.89%] and 0.23% [min 0.01%−max 2.81%] were found in MVP and PP phantoms, respectively. For each target volume, the obtained results in terms of gamma index passing rate show an agreement >95% with 5% 2 mm and 3% 2 mm criteria for both 2D and 3D distributions. The obtained results confirmed that the use of a single isocenter for multiple lesions reduces the treatment time without compromising accuracy, even in the case of target volumes that are quite distant from the isocenter.
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Affiliation(s)
- Lucia Zirone
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Elisa Bonanno
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Giuseppina Rita Borzì
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Nina Cavalli
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Alessia D’Anna
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
| | - Rosaria Galvagno
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
| | - Andrea Girlando
- Radiotherapy Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy;
| | - Anna Maria Gueli
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
| | - Martina Pace
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
| | - Giuseppe Stella
- Department of Physics and Astronomy E. Majorana, University of Catania, 95123 Catania, Italy; (A.D.); (R.G.); (A.M.G.)
- Correspondence: ; Tel.: +39-328-1847570
| | - Carmelo Marino
- Medical Physics Department, Humanitas Istituto Clinico Catanese, 95045 Catania, Italy; (L.Z.); (E.B.); (G.R.B.); (N.C.); (M.P.); (C.M.)
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Stella G, Cavalli N, Bonanno E, Zirone L, Borzì GR, Pace M, Girlando A, Gueli AM, Marino C. SBRT/SRS patient-specific QA using GAFchromic TM EBT3 and FilmQA TM Pro software. J Radiosurg SBRT 2022; 8:37-45. [PMID: 35387411 PMCID: PMC8930055] [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] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 11/02/2021] [Indexed: 01/03/2023]
Abstract
The aim of this work is to verify the potential use of GAFchromicTM EBT3 and FILMQATM pro software for patient specific quality assurance (QA) for stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) treatment plans in clinical routine use. In particular, encephalic, pulmonary and lymph node treatments plans were selected for this study. The agreement between the calculated and measured dose distributions were evaluated in terms of ɣ index with 3%3mm, 2%2mm, 1.5%1.5mm and 3%1.5mm criteria. The obtained results were then compared to the routine pre-treatment verification method which uses electronic portal imaging device (EPID) and EPIQA analysis software. EBT3-FilmQA method results show a mean ɣ index passing rate >95% with 2%1.5mm analysis criteria and an improvement of about 7% compared with EPID-EPIQA method results.
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Affiliation(s)
- Giuseppe Stella
- Physics for Dating Diagnostic Dosimetry Research and Applications (PH3DRA) Laboratories, Dipartimento di Fisica e Astronomia, Università di Catania, via Santa Sofia 64, I-95123 Catania, Italy, Department of Medical Physics - Humanitas, Istituto Clinico Catanese - contrada Cubba S.P. 54 n.11, Misterbianco (CT), Italy
| | - Nina Cavalli
- Department of Medical Physics - Humanitas, Istituto Clinico Catanese - contrada Cubba S.P. 54 n.11, Misterbianco (CT), Italy
| | - Elisa Bonanno
- Department of Medical Physics - Humanitas, Istituto Clinico Catanese - contrada Cubba S.P. 54 n.11, Misterbianco (CT), Italy
| | - Lucia Zirone
- School of Medical Physics, University of Catania, Italy
| | - Giuseppina Rita Borzì
- Department of Medical Physics - Humanitas, Istituto Clinico Catanese - contrada Cubba S.P. 54 n.11, Misterbianco (CT), Italy
| | - Martina Pace
- School of Medical Physics, University of Catania, Italy
| | - Andrea Girlando
- Department of Radiotherapy - Humanitas, Istituto Clinico Catanese - contrada Cubba S.P. 54 n.11, Misterbianco (CT), Italy
| | - Anna. M. Gueli
- Physics for Dating Diagnostic Dosimetry Research and Applications (PH3DRA) Laboratories, Dipartimento di Fisica e Astronomia, Università di Catania, via Santa Sofia 64, I-95123 Catania, Italy
| | - Carmelo Marino
- Department of Medical Physics - Humanitas, Istituto Clinico Catanese - contrada Cubba S.P. 54 n.11, Misterbianco (CT), Italy
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Ferini G, Viola A, Valenti V, Tripoli A, Molino L, Marchese VA, Illari SI, Rita Borzì G, Prestifilippo A, Umana GE, Martorana E, Mortellaro G, Ferrera G, Cacciola A, Lillo S, Pontoriero A, Pergolizzi S, Parisi S. Whole Brain Irradiation or Stereotactic RadioSurgery for five or more brain metastases (WHOBI-STER): A prospective comparative study of neurocognitive outcomes, level of autonomy in daily activities and quality of life. Clin Transl Radiat Oncol 2021; 32:52-58. [PMID: 34926839 PMCID: PMC8649107 DOI: 10.1016/j.ctro.2021.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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: 06/05/2021] [Revised: 11/18/2021] [Accepted: 11/21/2021] [Indexed: 02/07/2023] Open
Abstract
The main aim of MBM treatment is to palliate neurological symptoms and to maintain an adequate QoL. SRT could be the “new standard” over WBI in the management of MBM patients. Neurocognitive functions could deteriorate more after WBI than after SRT.
Aims To evaluate neurocognitive performance, daily activity and quality of life (QoL), other than usual oncologic outcomes, among patients with brain metastasis ≥5 (MBM) from solid tumors treated with Stereotactic Brain Irradiation (SBI) or Whole Brain Irradiation (WBI). Methods This multicentric randomized controlled trial will involve the enrollment of 100 patients (50 for each arm) with MBM ≥ 5, age ≥ 18 years, Karnofsky Performance Status (KPS) ≥ 70, life expectancy > 3 months, known primary tumor, with controlled or controllable extracranial disease, baseline Montreal Cognitive Assessment (MoCA) score ≥ 20/30, Barthel Activities of Daily Living score ≥ 90/100, to be submitted to SBI by LINAC with monoisocentric technique and non-coplanar arcs (experimental arm) or to WBI (control arm). The primary endpoints are neurocognitive performance, QoL and autonomy in daily-life activities variations, the first one assessed by MoCa Score and Hopkins Verbal Learning Test-Revised, the second one through the EORTC QLQ-C15-PAL and QLQ-BN-20 questionnaires, the third one through the Barthel Index, respectively. The secondary endpoints are time to intracranial failure, overall survival, retreatment rate, acute and late toxicities, changing of KPS. It will be considered significant a statistical difference of at least 30% between the two arms (statistical power of 80% with a significance level of 95%). Discussion Several studies debate what is the decisive factor accountable for the development of neurocognitive decay among patients undergoing brain irradiation for MBM: radiation effect on clinically healthy brain tissue or intracranial tumor burden? The answer to this question may come from the recent technological advancement that allows, in a context of a significant time saving, improved patient comfort and minimizing radiation dose to off-target brain, a selective treatment of MBM simultaneously, otherwise attackable only by WBI. The achievement of a local control rate comparable to that obtained with WBI remains the fundamental prerequisite. Trial registration NCT number: NCT04891471.
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Key Words
- 3D-CRT, 3Dimensional-ConformalRadioTherapy
- Autonomy in daily activities
- BSC, Best Supportive Care
- Brain metastases
- CRF, Case Report Form
- CT, Computerized Tomography
- CTV, Clinical Target Volume
- EORTC QLQ-C15-PAL, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 15 for Palliative Care
- FSRT, Fractionated Stereotactic Radiation Therapy
- GTV, Gross Tumor Volume
- KPS, Karnofsky Performance Status
- LINAC, Linear Accelerator
- MBM, Multiple Brain Metastastes
- MRI, Magnetic Resonance Imaging
- MoCA, Montreal Cognitive Assessment
- NCCN, National Comprehensive Cancer Network
- Neurocognitive decay
- Neurocognitive performance
- Neurocognitive tests
- OAR, Organ At Risk
- OS, Overall Survival
- PTV, Planning Target Volume
- Palliative care
- QLQ-BN20, Quality of Life Questionnaire - Brain Neoplasm 20
- QoL, Quality of Life
- Quality of life
- RT, Radiation Therapy
- RTOG, Radiation Therapy Oncology Group
- Radiotherapy for multiple brain metastases
- SBI, Stereotactic Brain Irradiation
- SRS, Stereotactic RadioSurgery
- SRT, Stereotactic Radiation Therapy
- Stereotactic Brain RadioSurgery
- Stereotactic Brain Radiotherapy
- Supportive care in cancer patients
- VEGF, Vascular Endothelial Growth Factor
- Whole Brain Radiotherapy
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Affiliation(s)
| | - Anna Viola
- Fondazione IOM, Viagrande, I-95029 Catania, Italy
| | - Vito Valenti
- REM Radioterapia srl, Viagrande, I-95029 Catania, Italy
| | | | - Laura Molino
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy
| | | | | | | | - Angela Prestifilippo
- Medical Oncology Unit, Mediterranean Institute of Oncology, Viagrande, I-95029 Catania, Italy
| | - Giuseppe Emmanuele Umana
- Trauma Center, Gamma Knife Center, Department of Neurosurgery, Cannizzaro Hospital, I-95125 Catania, Italy
| | | | - Gianluca Mortellaro
- Department of Radiation Oncology, ARNAS Ospedale Civico, I-90127 Palermo, Italy
| | - Giuseppe Ferrera
- Department of Radiation Oncology, ARNAS Ospedale Civico, I-90127 Palermo, Italy
| | - Alberto Cacciola
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy
| | - Sara Lillo
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy
| | - Antonio Pontoriero
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy
| | - Stefano Pergolizzi
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy
| | - Silvana Parisi
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy
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Ferini G, Valenti V, Puliafito I, Illari SI, Marchese VA, Borzì GR. Volumetric Modulated Arc Therapy Capabilities for Treating Lower-Extremity Skin Affected by Several Merkel Cell Carcinoma Nodules: When Technological Advances Effectively Achieve the Palliative Therapeutic Goal while Minimising the Risk of Potential Toxicities. Medicina (Kaunas) 2021; 57:medicina57121379. [PMID: 34946324 PMCID: PMC8703259 DOI: 10.3390/medicina57121379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 12/25/2022]
Abstract
The peculiar and rare clinical condition below clearly requires a customized care approach in the context of personalized medicine. An 80-year-old female patient who was subjected in 2018 to surgical removal of a cutaneous Merkel cell carcinoma (MCC) nodule located on the posterior surface of the left thigh and to three subsequent palliative radiotherapy treatments developed a fourth relapse in October 2020, with fifteen nodular metastases located in the left thigh and leg. Since the overall macroscopic disease was still exclusively regionally located and microscopic spread was likely extended also to clinically negative skin of the thigh and leg, we performed an irradiation of the whole left lower extremity. For this purpose the total target (65.5 cm) was divided into three sub-volumes. Dose prescription was 30 Gy in 15 daily fractions. A sequential boost of 10 Gy in 5 daily fractions was planned for macroscopic nodules. Plans were calculated by means of volumetric modulated arc therapy (VMAT) with the field overlap technique. Thanks to this, we obtained a homogeneous dose distribution in the field junction region; avoidance structures were delineated in the central part of the thigh and leg with the aim of achieving an optimal superficial dose painting and to reduce bone exposure to radiation. This case study demonstrates that VMAT allows for a good dose coverage for circumferential cutaneous targets while sparing deeper organs at risk. A reproducible image-guided set-up is fundamental for an accurate and safe dose delivery. However, local treatments such as radiotherapy for very advanced MCC of the lower extremities might have limited impact due to the high probability of systemic progression, as illustrated in this case. Radiation is confirmed as being effective in preventing MCC nodule progression toward skin wounding.
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Affiliation(s)
- Gianluca Ferini
- REM Radioterapia srl, Via Penninazzo 11, I-95029 Viagrande, CT, Italy; (V.V.); (V.A.M.)
- Correspondence: ; Tel.: +39-095-78-94-581
| | - Vito Valenti
- REM Radioterapia srl, Via Penninazzo 11, I-95029 Viagrande, CT, Italy; (V.V.); (V.A.M.)
| | - Ivana Puliafito
- Medical Oncology Unit, Mediterranean Institute of Oncology, I-95029 Viagrande, CT, Italy;
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Ferini G, Tripoli A, Molino L, Cacciola A, Lillo S, Parisi S, Umina V, Illari SI, Marchese VA, Cravagno IR, Borzì GR, Valenti V. How Much Daily Image-guided Volumetric Modulated Arc Therapy Is Useful for Proctitis Prevention With Respect to Static Intensity Modulated Radiotherapy Supported by Topical Medications Among Localized Prostate Cancer Patients? Anticancer Res 2021; 41:2101-2110. [PMID: 33813420 DOI: 10.21873/anticanres.14981] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 02/13/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM To evaluate if topical support therapy during static-intensity modulated radiotherapy (sIMRT) course is able to equal the characteristic minimum risk for radiation proctitis of Image-guided volumetric modulated arc therapy (IG-VMAT) treatment among localized prostate cancer patients. PATIENTS AND METHODS Rectal toxicity data of the above patients were retrospectively collected throughout three different clinical periods at our Radiotherapy Deparment: from October 2011 to December 2012, prostate cancer patients were treated with sIMRT and in advance supported by means of daily topical corticosteroids; from January 2013 to November 2016, topical corticosteroids were replaced by daily hyaluronic acid enemas; from December 2016 to May 2018 eligible patients were treated with newly introduced IG-VMAT supported by only on-demand topical corticosteroids. RESULTS Among 359 eligible patients, IG-VMAT was proven generally more effective than sIMRT supported by topical medications in terms of proctitis reduction, although without clinical and practical relevance. CONCLUSION Topical medications might have a role in radiation proctitis prevention.
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Affiliation(s)
| | | | - Laura Molino
- Radiation Oncology Unit - Department of Biomedical, Dental Science and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Alberto Cacciola
- Radiation Oncology Unit - Department of Biomedical, Dental Science and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Sara Lillo
- Radiation Oncology Unit - Department of Biomedical, Dental Science and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Silvana Parisi
- Radiation Oncology Unit - Department of Biomedical, Dental Science and Morphological and Functional Images, University of Messina, Messina, Italy
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Landoni V, Borzì GR, Strolin S, Bruzzaniti V, Soriani A, D'Alessio D, Ambesi F, Di Grazia AM, Strigari L. Clinical evaluation of X-ray voxel Monte Carlo versus pencil beam-based dose calculation in stereotactic body radiotherapy of lung cancer under normal and deep inspiration breath hold. Technol Cancer Res Treat 2014; 14:334-42. [PMID: 25223324 DOI: 10.1177/1533034614547451] [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: 12/12/2013] [Accepted: 05/28/2014] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study is to evaluate the differences between dose distributions calculated with the pencil beam (PB) and X-ray voxel Monte Carlo (MC) algorithms for patients with lung cancer using intensity-modulated radiotherapy (IMRT) or HybridArc techniques. The 2 algorithms were compared in terms of dose-volume histograms, under normal and deep inspiration breath hold, and in terms of the tumor control probability (TCP). The dependence of the differences in tumor volume and location was investigated. Dosimetric validation was performed using Gafchromic EBT3 (International Specialty Products, ISP, Wayne, NJ). Forty-five Computed Tomography (CT) data sets were used for this study; 40 Gy at 8 Gy/fraction was prescribed with 5 noncoplanar 6-MV IMRT beams or 3 to 4 dynamic conformal arcs with 3 to 5 IMRT beams distributed per arc. The plans were first calculated with PB and then recalculated with MC. The difference between the mean tumor doses was approximately 10% ± 4%; these differences were even larger under deep inspiration breath hold. Differences between the mean tumor dose correlated with tumor volume and path length of the beams. The TCP values changed from 99.87% ± 0.24% to 96.78% ± 4.81% for both PB- and MC-calculated plans (P = .009). When a fraction of hypoxic cells was considered, the mean TCP values changed from 76.01% ± 5.83% to 34.78% ± 18.06% for the differently calculated plans (P < .0001). When the plans were renormalized to the same mean dose at the tumor, the mean TCP for oxic cells was 99.05% ± 1.59% and for hypoxic cells was 60.20% ± 9.53%. This study confirms that the MC algorithm adequately accounts for inhomogeneities. The inclusion of the MC in the process of IMRT optimization could represent a further step in the complex problem of determining the optimal treatment plan.
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Affiliation(s)
- V Landoni
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome, Italy
| | - G R Borzì
- REM Radioterapia, Catania-Istituto Oncologico del Mediterraneo (IOM), Viagrande (CT), Italy
| | - S Strolin
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome, Italy
| | - V Bruzzaniti
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome, Italy
| | - A Soriani
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome, Italy
| | - D D'Alessio
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome, Italy
| | - F Ambesi
- Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome, Italy
| | - A M Di Grazia
- REM Radioterapia, Catania-Istituto Oncologico del Mediterraneo (IOM), Viagrande (CT), Italy
| | - L Strigari
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome, Italy
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