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BalajiSubramanian S, Al-Hajri T, Satyapal N, Al-Bulushi M, Al Sheibani SM, Al Kalbani FKM, Al-Saadi M, Al Musalhi MN, Al Wahshi HA. A Rare Case of Dual Metachronous Primary Malignancies, Chronic Myeloid Leukemia, and Tongue Carcinoma in a Patient With Long-Standing Systemic Lupus Erythematosus: A Case Report and Review of Literature. Cureus 2024; 16:e56648. [PMID: 38646281 PMCID: PMC11032168 DOI: 10.7759/cureus.56648] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2024] [Indexed: 04/23/2024] Open
Abstract
Patients with long-standing autoimmune diseases like systemic lupus erythematosus (SLE) are at a higher risk of developing hematological malignancies. However, chronic myeloid leukemia (CML) has rarely been reported in patients with SLE. Advancements in medical diagnostics and treatment have led to the life expectancy of SLE and CML patients moving closer to that of the general population, and it is not uncommon to encounter more than one malignancy in a cancer survivor. Although squamous cell carcinoma (SCC) of the skin has been reported in CML patients, mucosal SCC of the head and neck has rarely only been reported in CML survivors. The objective of this case report is to share our experience in treating a patient with dual metachronous primary malignancies, CML, and tongue carcinoma, along with long-standing SLE, managed by a multidisciplinary team.
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Affiliation(s)
| | - Thuraya Al-Hajri
- Department of Radiation Oncology, The Royal Hospital, Muscat, OMN
| | - Namrata Satyapal
- Department of Radiation Oncology, The Royal Hospital, Muscat, OMN
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Fujiwara M, Kitada F. Clinical Experience of Intra-tumoral Central-Dose Escalated Volumetric Modulated Arc Therapy for Lymph Node Metastases in Patients With Advanced Cancer. Cureus 2023; 15:e34995. [PMID: 36938256 PMCID: PMC10020031 DOI: 10.7759/cureus.34995] [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] [Accepted: 02/07/2023] [Indexed: 02/16/2023] Open
Abstract
Background Lymph node metastases (LN mets) are radioresistant, and high-dose irradiation is preferred for their control. The volumetric-modulated arc therapy technique makes it possible to perform intra-tumoral dose escalation without increasing the total prescribed dose of fractionated irradiation. We report its clinical experiences with intra-tumoral central-dose escalated volumetric-modulated arc therapy (ICE-VMAT) for LN mets. Materials and methods This study retrospectively evaluated 31 patients with 50 LN mets from stage III and IV advanced cancers who received ICE-VMAT. The total described dose was 50 Gy, and the median intra-tumoral central dose was 66 Gy (range, 54-79 Gy). Results The median follow-up period was 21 months. The two-year local control and overall survival (OS) rates were 95% and 56%, whereas univariate analysis revealed that the KPS ≥ 80 group had a significantly better OS compared to the KPS < 80 group. Conclusion ICE-VMAT was effective for LN mets. Patients with good KPS may benefit from therapeutic intervention with ICE-VMAT, even if they have multiple distant LN mets.
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Takakusagi Y, Usui K, Mizoguchi N, Nagatsuka J, Hikage T, Kodama Y, Ezura T, Kusunoki T, Oizumi Y. Comparison of Moderate Hypofractionated Volumetric-Modulated Arc Therapy Plans With and Without Flattening Filter for Localized Prostate Cancer. Cureus 2021; 13:e18034. [PMID: 34671522 PMCID: PMC8520568 DOI: 10.7759/cureus.18034] [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] [Accepted: 09/16/2021] [Indexed: 12/24/2022] Open
Abstract
Background/Aim The aim of this study was to compare volumetric-modulated arc therapy (VMAT) radiation plans between conventional VMAT with flattening filter (cFF-VMAT) and flattening filter-free VMAT (FFF-VMAT) for localized prostate cancer. Materials and methods Ten patients with localized prostate cancer who underwent cFF-VMAT at Yokosuka General Hospital Uwamachi, Yokosuka, Japan, from July 2020 to October 2020 were enrolled. Dose-volume histogram (DVH) parameters of the target volume, normal organs, monitor units (MU), and beam-on time (BOT) were compared between cFF-VMAT and FFF-VMAT plans. Results No significant difference was observed for DVH parameters for the target volume. No significant difference was observed in all parameters for the bladder and rectum between the cFF-VMAT and FFF-VMAT groups. The mean values of MU were 686 ± 52 and 784 ± 80 in cFF-VMAT and FFF-VMAT, respectively (p < 0.001). The mean BOT was 97.0 ± 6.6 s and 72.9 ± 1.4 s for cFF-VMAT and FFF-VMAT, respectively (p < 0.001). Conclusion DVH parameters of the target volume and normal organs were not significantly different between the cFF-VMAT and FFF-VMAT plans. In FFF-VMAT, MU was significantly higher, and the BOT was significantly shorter than those in cFF-VMAT.
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Affiliation(s)
- Yosuke Takakusagi
- Department of Radiation Oncology, Kanagawa Cancer Center, Yokohama, JPN
| | - Keisuke Usui
- Department of Radiation Oncology, Juntendo University, Tokyo, JPN
| | | | - Jun Nagatsuka
- Department of Radiology, Yokosuka General Hospital Uwamachi, Yokosuka, JPN
| | - Takeshi Hikage
- Department of Radiology, Yokosuka General Hospital Uwamachi, Yokosuka, JPN
| | - Yasuhiko Kodama
- Department of Radiology, Yokosuka General Hospital Uwamachi, Yokosuka, JPN
| | - Takatomo Ezura
- Section of Medical Physics and Engineering, Kanagawa Cancer Center, Yokohama, JPN
| | - Terufumi Kusunoki
- Section of Medical Physics and Engineering, Kanagawa Cancer Center, Yokohama, JPN
| | - Yukio Oizumi
- Department of Radiation Oncology, Yokosuka General Hospital Uwamachi, Yokosuka, JPN
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Stanley D, McConnell K, Iqbal Z, Everett A, Dodson J, Keene K, McDonald A. Dosimetric Evaluation Between the Conventional Volumetrically Modulated Arc Therapy ( VMAT) Total Body Irradiation (TBI) and the Novel Simultaneous Integrated Total Marrow Approach (SIMBa) VMAT TBI. Cureus 2021; 13:e15646. [PMID: 34306856 PMCID: PMC8279336 DOI: 10.7759/cureus.15646] [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] [Accepted: 06/12/2021] [Indexed: 11/05/2022] Open
Abstract
Purpose The purpose of this study was to assess the treatment planning feasibility of volumetrically modulated arc therapy total body irradiation (VMAT TBI) using a simultaneous integrated marrow and body approach (SIMBa). We also aimed to compare SIMBa TBI with the more conventional VMAT TBI approach using the entire body as the target. The goal of using an integrated approach like SIMBa is to balance the known clinical benefit of TBI with the toxicity decrease of Total Marrow Irradiation (TMI) using two prescription volumes. In anticipation of a clinical trial to investigate a novel conditioning regimen that uses SIMBa, our institution retrospectively analyzed the dosimetric differences between 20 clinical VMAT TBI which were re-planned using SIMBa. Methods Twenty patients who previously received conventional VMAT TBI at our institution with a dose of 12 Gy in six fractions were re-planned using SIMBa with a planning aim of delivering a uniform dose of 12 Gy to at least 90% of the PTV_BodyEval. The planning aims of SIMBa were to deliver a uniform dose of 12 Gy to at least 90% of the PTV_Marrow and 8 Gy to at least 90% of the PTV_TotalBody while limiting the mean lung dose to less than 8 Gy. The plans were normalized so that 100% of the PTV_Marrow received at least 90% of the dose with the PTV_TotalBody optimized to stay as close to 100% at 90% as possible. Results All 20 patient plans achieved 12 Gy/8 Gy to at least 90% of the PTV_Marrow and PTV_TotalBody, respectively, with max doses of <16 Gy (130%). As compared with the delivered TBI, the following reductions in mean dose were notable: small bowel 21.3±4.2%, lung 16.3±7.9%, heart 25.3±8.6%, and kidney 16.4±6.2%. Coverage of the sanctuary sites was maintained despite a significant reduction to sensitive organs at risk (OARs). Conclusion This study supports that VMAT TBI treatment planning with SIMBa is feasible. In this sample, SIMBa provided dosimetrically similar doses to marrow and sanctuary site doses as TBI while achieving lower doses to OARs. A clinical trial is needed to investigate the clinical implications of VMAT TBI with SIMBa.
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Affiliation(s)
- Dennis Stanley
- Radiation Oncology, The University of Alabama at Birmingham, Birmingham, USA
| | - Kristen McConnell
- Radiation Oncology/Medical Physics, The University of Alabama at Birmingham, Birmingham, USA
| | - Zohaib Iqbal
- Radiation Oncology/Medical Physics, The University of Alabama at Birmingham, Birmingham, USA
| | - Ashlyn Everett
- Radiation Oncology, The University of Alabama at Birmingham, Birmingham, USA
| | - Jonathan Dodson
- Radiation Oncology, The University of Alabama at Birmingham, Birmingham, USA
| | - Kimberly Keene
- Radiation Oncology, The University of Alabama at Birmingham, Birmingham, USA
| | - Andrew McDonald
- Radiation Oncology, The University of Alabama at Birmingham, Birmingham, USA
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Gude Z, Adamson J, Kirkpatrick JP, Giles W. Hippocampal Avoidance in Multitarget Radiosurgery. Cureus 2021; 13:e15399. [PMID: 34249548 PMCID: PMC8253338 DOI: 10.7759/cureus.15399] [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] [Accepted: 05/22/2021] [Indexed: 11/16/2022] Open
Abstract
Brain metastases are a common complication for patients diagnosed with cancer. As stereotactic radiosurgery (SRS) becomes a more prevalent treatment option for patients with many brain metastases, further research is required to better characterize the ability of SRS to treat large numbers of metastases (≥4) and the impact on normal brain tissue and, ultimately, neurocognition and quality of life (QOL). This study serves first as an evaluation of the feasibility of hippocampal avoidance for SRS patients, specifically receiving single-isocenter multitarget treatments (SIMT) planned with volumetric modulated arc therapy (VMAT). Second, this study analyzes the effects of standard-definition (SD) multileaf collimators (MLCs) (5 mm width) on plan quality and hippocampal avoidance. The 40 patients enrolled in this Institutional Review Board (IRB)-approved study had between four and 10 brain metastases and were treated with SIMT using VMAT. From the initial 40 patients, eight hippocampi across seven patients had hippocampal doses exceeding the maximum biologically effective dose (BED) constraint given by RTOG 0933. With the addition of upper constraints in the optimization objectives and one arc angle adjustment in one patient plan, four out of seven patient plans were able to meet the maximum hippocampal BED constraint, avoiding five out of eight total hippocampi at risk. High-definition (HD) MLCs allowed for an average decrease of 29% ± 23% (p = 0.007) in the maximum BED delivered to all eight hippocampi at risk. The ability to meet dose constraints depended on the distance between the hippocampus and the nearest planning target volume (PTV). Meeting the maximum hippocampal BED constraint in re-optimized plans was equally likely with the use of SD-MLCs (five out of eight hippocampi at risk were avoided) but resulted in increased dose to normal tissue volumes (23.67% ± 16.3% increase in V50%[cc] of normal brain tissue, i.e., brain volume subtracted by the total PTV) when compared to the HD-MLC re-optimized plans. Comparing the effects of SD-MLCs on plans not optimized for hippocampal avoidance resulted in increases of 48.2% ± 32.2% (p = 0.0056), 31.5% ± 16.3% (p = 0.024), and 16.7% ± 8.5% (p = 0.022) in V20%[cc], V50%[cc], and V75%[cc], respectively, compared to the use of HD-MLCs. The conformity index changed significantly neither when plans were optimized for hippocampal avoidance nor when SD-MLC leaves were used for treatment. In plans not optimized for hippocampal avoidance, mean hippocampal dose increased with the use of SD-MLCs by 38.0% ± 37.5% (p = 0.01). However, the use of SD-MLCs did not result in an increased number of hippocampi at risk.
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Affiliation(s)
| | - Justus Adamson
- Radiation Oncology, Duke University Medical Center, Durham, USA
| | | | - William Giles
- Radiation Oncology, Duke University Medical Center, Durham, USA
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Serra M, Ametrano G, Borzillo V, Quarto M, Muto M, Di Franco R, Federica S, Loffredo F, Paolo M. Dosimetric comparison among cyberknife, helical tomotherapy and VMAT for hypofractionated treatment in localized prostate cancer. Medicine (Baltimore) 2020; 99:e23574. [PMID: 33327317 PMCID: PMC7738085 DOI: 10.1097/md.0000000000023574] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Hypofractionation for localized prostate cancer treatment is rapidly spreading in the medical community and it is supported by radiobiological evidences (lower α/β ratio compared with surrounding tissues). Stereotactic body radiation therapy (SBRT) is a technique to administer high doses with great precision, which is commonly performed with CyberKnife (CK) in prostate cancer treatment. Since the CyberKnife (CK) is not available at all radiotherapy center, alternative SBRT techniques are available such as Volumetric Modulated Arc Therapy (VMAT) and Helical Tomotherapy (HT). The aim of the present study was to compare the dosimetric differences between the CK, VMAT, and HT plans for localized prostate cancer treatment.Seventeenpatients have been recruited and replanned using VMAT and HT to this purpose: they received the treatment using the CK with a prescription of 36.25 Gy in 5 fractions; bladder, rectum and penis bulb were considered as organs at risk (OAR). In order to compare the techniques, we considered DVHs, PTV coverage, Conformity Index and new Conformity Index, Homogeneity Index, beam-on time and OARs received dose.The 3 treatments methods showed a comparable coverage of the lesion (PTV 95%: 99.8 ± 0.4% CK; 98.5 ± 0.8% VMAT; 99.4 ± 0.5% HT. P < .05) and good sparing of OARs. Nevertheless, the beam-on time showed a significant difference (37 ± 9 m CK; 7.1 ± 0.3 m VMAT; 17 ± 2 m HT. P < .05).Our results showed that, although CK is the best SBRT technique for prostate cancer treatment, in case this technology is not available, it can be replaced by a similar treatment delivered by VMAT technique. VMAT can be administrated only if it has an appropriate Image Guided Radiation Therapy (IGRT) tracking system.
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Affiliation(s)
- Marcello Serra
- Dipartimento di Scienze Biomediche Avanzate, Università degli Studi di Napoli Federico II – Napoli
| | - Gianluca Ametrano
- Department of Radiation Oncology, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale - Naples
| | - Valentina Borzillo
- Department of Radiation Oncology, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale - Naples
| | - Maria Quarto
- Dipartimento di Scienze Biomediche Avanzate, Università degli Studi di Napoli Federico II – Napoli
| | - Matteo Muto
- Dipartimento Onco-Ematologico Radioterapia, Azienda ospedaliera San Giuseppe Moscati – Avellino, Italy
| | - Rossella Di Franco
- Department of Radiation Oncology, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale - Naples
| | - Savino Federica
- Dipartimento di Scienze Biomediche Avanzate, Università degli Studi di Napoli Federico II – Napoli
| | - Filomena Loffredo
- Dipartimento di Scienze Biomediche Avanzate, Università degli Studi di Napoli Federico II – Napoli
| | - Muto Paolo
- Department of Radiation Oncology, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale - Naples
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Barsky AR, Lin H, Mendes A, Dreyfuss A, Wright C, Anstadt EJ, Berman AT, Levin WP, Cengel KA, Anderson N, Dong L, Metz JM, Li T, Feigenberg S. Initial Clinical Experience Treating Patients With Lung Cancer on a 6MV-Flattening-Filter-Free O-Ring Linear Accelerator. Cureus 2020; 12:e10325. [PMID: 33052286 PMCID: PMC7546605 DOI: 10.7759/cureus.10325] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Introduction Modern technologies, like intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT), have improved the therapeutic ratio of thoracic radiotherapy (TRT) for lung cancer (LC). Halcyon™ (Varian Medical Systems, Palo Alto, CA, USA), a novel 6MV-flattening-filter-free O-ring linear accelerator (6X-FFF ORL), was designed to deliver IMRT and VMAT with greater speed than a C-arm linac. Herein, we report our initial clinical experience treating patients with LC on this linac. Methods All patients who received TRT for LC on the 6X-FFF ORL at our institution were retrospectively identified. Patients' clinicopathologic data, radiotherapy details, early disease-control and toxicity outcomes, dosimetric data, couch corrections, and treatment times are reported. Results Between 10/2018-12/2019, 30 consecutive patients (median age 66 years, range 54-94 years) received definitive or post-operative TRT for LC (median 66 Gy/33 fractions; range 5-70 Gy/2-37 fractions) following four-dimensional computed tomography (CT) simulation (97%) using daily kilovoltage KV cone-beam CT (CBCT) (100%) on a 6X-FFF ORL for non-small cell LC (84%) or small cell LC (16%), with 53% receiving VMAT, 43% receiving static-field IMRT, and 77% receiving concurrent systemic therapy. All plans were approved through institutional peer review. The average three-dimensional vector couch correction based on CBCT guidance was 0.90 ± 0.50 cm. The average beam-on and beam on plus CBCT times were 1.7 ± 1.1 min, and 5.0 ± 3.2 min, respectively. Grade 3 dyspnea and fatigue occurred in 3% and 3% of patients, respectively. There were no grade ≥4 toxicities. Conclusion In this first clinical report of TRT for LC on a 6X-FFF ORL, daily CBCT-guided treatment was fast and safe with respect to dosimetry and clinical outcomes. Thus, use of this linac for TRT may increase LC patient throughput without a detriment in radiotherapy quality.
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Affiliation(s)
- Andrew R Barsky
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Hui Lin
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Amberly Mendes
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Alexandra Dreyfuss
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Christopher Wright
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Emily J Anstadt
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Abigail T Berman
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - William P Levin
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Keith A Cengel
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Nathan Anderson
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Lei Dong
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - James M Metz
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Taoran Li
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Steven Feigenberg
- Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA
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Mak DY, Fraser I, Ferris R, James K, Liu M, Thomas SD, McKenzie M, Lefresne S. Comparison of Rapid to Standard Volumetric Modulated Arc Therapy for Palliative Radiotherapy in Lung Cancer Patients. Cureus 2020; 12:e10055. [PMID: 32999778 PMCID: PMC7520402 DOI: 10.7759/cureus.10055] [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: 03/19/2020] [Accepted: 08/26/2020] [Indexed: 11/05/2022] Open
Abstract
Patients with incurable lung cancer often present with debilitating symptoms that require urgent palliative radiotherapy. Volumetric modulated arc therapy (VMAT) provides several dosimetric advantages compared to basic non-conformal techniques, but involves complex planning resulting in a slower turn-around time for treatment. A simplified planning technique known as 'rapid VMAT' was developed with an aim to deliver palliative treatment to patients within 48 hours. The purpose of this study was to prospectively compare the dosimetric quality of rapid VMAT plans to standard VMAT plans. Fourteen consecutive rapid VMAT cases were re-planned de novo as per standard VMAT planning guidelines. Planning target volume (PTV) and organs at risk (OARs) were then compared. PTV coverage and dose to OARs including the spinal canal, lung, heart, and esophagus were similar between rapid and standard VMAT. Each plan was ready for treatment within 48 hours of the CT simulation. This study describes an expedited process for which palliative radiotherapy can be delivered to lung tumors with a similar robust quality that is provided for curative intent VMAT radiotherapy plans.
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Affiliation(s)
- David Y Mak
- Medicine, University of British Columbia, Vancouver, CAN
| | - Ian Fraser
- Radiation Oncology, British Columbia Cancer Agency, Vancouver, CAN
| | - Robynn Ferris
- Radiation Oncology, British Columbia Cancer Agency, Vancouver, CAN
| | - Kerry James
- Radiation Oncology, British Columbia Cancer Agency, Vancouver, CAN
| | - Mitchell Liu
- Radiation Oncology, British Columbia Cancer Agency, Vancouver, CAN
| | - Steven D Thomas
- Medical Physics, British Columbia Cancer Agency, Vancouver, CAN
| | - Michael McKenzie
- Radiation Oncology, British Columbia Cancer Agency, Vancouver, CAN
| | - Shilo Lefresne
- Radiation Oncology, British Columbia Cancer Agency, Vancouver, CAN
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Taylor M, Williams J, Gleason JF. Effects of Multileaf Collimator Design and Function When Using an Optimized Dynamic Conformal Arc Approach for Stereotactic Radiosurgery Treatment of Multiple Brain Metastases With a Single Isocenter: A Planning Study. Cureus 2020; 12:e9833. [PMID: 32832305 PMCID: PMC7437117 DOI: 10.7759/cureus.9833] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 08/17/2020] [Indexed: 12/11/2022] Open
Abstract
Background Stereotactic radiosurgery (SRS) or fractionated SRS (fSRS) are effective options for the treatment of brain metastases. When treating multiple metastases with a linear accelerator-based approach, a single isocenter allows for efficient treatment delivery. In this study, we present our findings comparing dosimetric parameters of Brainlab (Munich, Germany) Elements™ Multiple Brain Mets SRS (MME) software (version 1.5 versus version 2.0) for a variety of scenarios and patients. The impact of multileaf collimator design and function on plan quality within the software was also evaluated. Materials and methods Twenty previously treated patients with a total of 58 lesions (from one to seven lesions each) were replanned with an updated version of the multiple brain Mets software solution. For each plan, the mean conformity index (CI), mean gradient index (GI), the volume of normal brain receiving 12 Gy (V12), and mean brain dose were evaluated. Additionally, all v2.0 plans were further evaluated with jaw tracking for by Elekta (Stockholm, Sweden) and HD120™ multileaf collimator by Varian Medical Systems (Palo Alto, USA). Results The new software version demonstrated improvements for CI, GI and V12 (p <0.01). For the Elekta Agility™ multileaf collimator, jaw tracking improved all dosimetric parameters except for CI (p =0.178) and mean brain dose (p =0.93). For the Varian with HD120 multileaf collimator, all parameters improved. Conclusions The software enhancements in v2.0 of the software provided improvements in planning efficiency and dosimetric parameters. Differences in multileaf collimator design may provide an additional incremental benefit in a subset of clinical scenarios.
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Affiliation(s)
| | | | - John F Gleason
- Radiation Oncology, Alliance Cancer Care, Huntsville, USA
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Smyth G, Evans PM, Bamber JC, Mandeville HC, Rollo Moore A, Welsh LC, Saran FH, Bedford JL. Dosimetric accuracy of dynamic couch rotation during volumetric modulated arc therapy (DCR- VMAT) for primary brain tumours. Phys Med Biol 2019; 64:08NT01. [PMID: 30808011 PMCID: PMC6877349 DOI: 10.1088/1361-6560/ab0a8e] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Radiotherapy treatment plans using dynamic couch rotation during volumetric modulated arc therapy (DCR-VMAT) reduce the dose to organs at risk (OARs) compared to coplanar VMAT, while maintaining the dose to the planning target volume (PTV). This paper seeks to validate this finding with measurements. DCR-VMAT treatment plans were produced for five patients with primary brain tumours and delivered using a commercial linear accelerator (linac). Dosimetric accuracy was assessed using point dose and radiochromic film measurements. Linac-recorded mechanical errors were assessed by extracting deviations from log files for multi-leaf collimator (MLC), couch, and gantry positions every 20 ms. Dose distributions, reconstructed from every fifth log file sample, were calculated and used to determine deviations from the treatment plans. Median (range) treatment delivery times were 125 s (123-133 s) for DCR-VMAT, compared to 78 s (64-130 s) for coplanar VMAT. Absolute point doses were 0.8% (0.6%-1.7%) higher than prediction. For coronal and sagittal films, respectively, 99.2% (96.7%-100%) and 98.1% (92.9%-99.0%) of pixels above a 20% low dose threshold reported gamma <1 for 3% and 3 mm criteria. Log file analysis showed similar gantry rotation root-mean-square error (RMSE) for VMAT and DCR-VMAT. Couch rotation RMSE for DCR-VMAT was 0.091° (0.086-0.102°). For delivered dose reconstructions, 100% of pixels above a 5% low dose threshold reported gamma <1 for 2% and 2 mm criteria in all cases. DCR-VMAT, for the primary brain tumour cases studied, can be delivered accurately using a commercial linac.
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Affiliation(s)
- Gregory Smyth
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom. Author to whom any correspondence should be addressed
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Li T, Scheuermann R, Lin A, Teo BKK, Zou W, Swisher-McClure S, Alonso-Basanta M, Lukens JN, Fotouhi Ghiam A, Kennedy C, Kim MM, Mihailidis D, Metz JM, Dong L. Impact of Multi-leaf Collimator Parameters on Head and Neck Plan Quality and Delivery: A Comparison between Halcyon™ and Truebeam® Treatment Delivery Systems. Cureus 2018; 10:e3648. [PMID: 30723647 PMCID: PMC6351111 DOI: 10.7759/cureus.3648] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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] [Indexed: 11/05/2022] Open
Abstract
Purpose A new dual-layer multi-leaf collimator (MLC) system with several improved characteristics was introduced with the Varian Halcyon™ treatment platform. This study evaluated this new MLC's impact on head and neck plan quality and delivery efficiency. Methods Nine patients were retrospectively studied with Institutional Review Board (IRB) approval. To compare plan quality between the Halcyon dual-layer MLC and Truebeam® MLC, all patients were replanned with the same prescription and target coverage following the institutional clinical protocol for both platforms and using both intensity modulated radiation therapy (IMRT) or volumetrically modulated arc therapy (VMAT) techniques. Organs-at-risk (OAR) dose-volume histogram (DVH) statistics were compared along with total plan monitor units (MU). To evaluate delivery efficiency, actual beam-on time for five patients' plans were recorded and compared. To evaluate the impact of MLC performance parameters on plan quality, virtual MLC models were generated by matching Truebeam MLC's parameters to those of the Halcyon dual-layer MLC both individually and combined. OAR doses were then compared between these virtual MLCs, the Truebeam MLC, and the actual Halcyon MLC. Results Overall the Halcyon dual-layer MLC provided similar plan quality compared to Truebeam MLC for VMAT plans, and improved sparing for majority of the OARs when using IMRT. Paired comparison showed median dose differences in mean doses to the parotids, cochlea, esophagus, and larynx ranged from -0.83 Gy to 0.37 Gy for VMAT, and from -4.79 Gy to -0.04 Gy for IMRT, with negative values indicating improved performance by Halcyon. Despite a slight increase in plan MU, the Halcyon reduced the total beam-on time by 42.8 ± 8.5%. Virtual MLC simulations demonstrated that matching MLC transmission accounted for nearly half of the total dose difference between Halcyon and Truebeam IMRT plans. Conclusion When compared to the Truebeam, the Halcyon's dual-layer MLC achieved similar plan quality using VMAT, and improved OAR sparing using IMRT, while providing nearly twice as fast treatment delivery. Reduction in MLC transmission is the dominating factor contributing to dosimetric differences in OAR sparing.
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Affiliation(s)
- Taoran Li
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Ryan Scheuermann
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Alexander Lin
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Boon-Keng Kevin Teo
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Wei Zou
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Samuel Swisher-McClure
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Michelle Alonso-Basanta
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - John N Lukens
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Alireza Fotouhi Ghiam
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Chris Kennedy
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Michele M Kim
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Dimitris Mihailidis
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - James M Metz
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Lei Dong
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
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Fawaz ZS, Kazandjian S, Tsui JM, Devic DS, Lecavalier-Barsoum M, Vuong T, Elakshar S, Garant A, Lavoie I, Niazi TM. What Is the Optimal Radiation Technique for Esophageal Cancer? A Dosimetric Comparison of Four Techniques. Cureus 2018; 10:e2985. [PMID: 30237946 PMCID: PMC6141055 DOI: 10.7759/cureus.2985] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 07/16/2018] [Indexed: 12/02/2022] Open
Abstract
Background Esophageal cancer treatment requires large radiation fields due to the deep location of the esophagus in the mediastinum and the high incidence of radial spread. There is no optimal radiation technique to ensure appropriate target coverage and minimal dose to all normal structures. Methods Fifteen consecutive cases of locally advanced esophageal cancer treated with radical chemoradiation (CRT) were analyzed. The total prescribed dose was 50.4 Gy in 28 fractions. A total of 60 plans were generated for analysis, including four different methods for each case. Method 1 consisted of a four-field conformal technique; method 2 was a two-plan technique (antero-posterior (AP), postero-anterior (PA), two posterior oblique fields (RPO and LPO)); method 3 was a three-field conformal technique (AP, LPO, RPO); and method 4 was a volumetric modulated arc radiotherapy (VMAT) technique. Dose ratios were calculated using the minimum, maximum, mean, and median doses of methods 2-4 over the dose of method 1. Ratios for the planning target volume (PTV) and to surrounding organs were analyzed. Results The mean PTV dose ratio ranged from 0.994 to 1.048 (SD = 0.01) representing an adequate target coverage for all techniques based on an analysis of variance (ANOVA). For the lungs, method 2 had the lowest lung V20 with a ratio of 0.861 (SD = 0.12), whereas method 3 had the highest with 1.644 (SD = 0.14). For the heart, method 3 had the lowest heart V40 with a mean dose ratio of 0.807 (SD = 0.09), whereas method 2 had the highest with 1.160 (SD = 0.11). For the liver, method 2 had the lowest V30 with a mean ratio of 0.857 (SD = 0.1) whereas method 4 had the highest with 1.672 (SD = 0.48). For the spinal cord, method 3 had the lowest mean dose ratio of 0.559 (SD = 0.09) whereas method 2 had the highest with 1.094 (SD = 0.04). Conclusion The four radiation techniques for esophageal cancer treatment were appropriate for target coverage. Method 2 had the most organ-sparing effect for the lungs and liver, and method 3 for the heart and spinal cord. VMAT did not add any significant sparing. A case-by-case decision should be made based on the patient's comorbidities.
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Affiliation(s)
- Ziad Simon Fawaz
- Radiation Oncology, McGill University Health Center, Montreal, CAN
| | - Suzanne Kazandjian
- Radiation Oncology, McGill University/Sir Mortimer B. Davis Jewish General Hospital, Montreal, CAN
| | - James M Tsui
- Oncology/Radiation Oncology, Cedars Cancer Centre/McGill University Health Centre, Montreal, CAN
| | - Dr Slobodan Devic
- Radiation Oncology, McGill University/Sir Mortimer B. Davis Jewish General Hospital, Montreal, CAN
| | | | - Te Vuong
- Radiation Oncology, McGill University/Sir Mortimer B. Davis Jewish General Hospital, Montreal, CAN
| | - Sara Elakshar
- Radiation Oncology, McGill University/Sir Mortimer B. Davis Jewish General Hospital, Montreal, CAN
| | - Aurelie Garant
- Radiation Oncology, McGill University Health Centre, Montreal, CAN
| | - Isabelle Lavoie
- Radiation Oncology, McGill University/Jewish General Hospital, Montreal, CAN
| | - Tamin M Niazi
- Oncology, McGill University Health Centre/Jewish General Hospital, Montreal , CAN
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Takanaka T, Taima Y, Horichi Y, Kawamori Y, Nobata K, Kitagawa K, Norishima A, Koshikawa K, Mito T, Yoshida S, Kawanaka T, Matsutani K, Kawahara M. Multiple Breath-hold Volumetric Modulated Arc Therapy Under Fluoroscopic Image Guidance with an Implanted Fiducial Marker: An Advanced Technique. Cureus 2018; 10:e2499. [PMID: 29951345 PMCID: PMC6019328 DOI: 10.7759/cureus.2499] [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: 03/19/2018] [Accepted: 04/17/2018] [Indexed: 11/05/2022] Open
Abstract
An advanced technique for multiple breath-hold volumetric modulated arc therapy (VMAT) has been proposed under fluoroscopic image guidance with a fiducial marker implanted close to a tumor. The marker coordinates on a digitally reconstructed radiography image at a gantry start angle, under a planned breath-hold condition, were transferred to the fluoroscopic image window. Then, a reference lateral line passing through the planned breath-hold marker position was drawn on the fluoroscopic image. Additional lateral lines were further added on both sides of the reference line with a distance of 3 mm as a tolerance limit for the breath-hold beam delivery. Subsequently, the patient was asked to breathe in slowly under fluoroscopy. Immediately after the marker position on the fluoroscopic image moved inside the tolerance range, the patient was asked to hold the breath and the VMAT beam was delivered. During the beam delivery, the breath-hold status was continuously monitored by checking if the deviation of the marker position exceeded the tolerance limit. As long as the marker stayed within the tolerance range, a segmented VMAT delivery continued for a preset period of 15 to 30 seconds depending on the breath-hold capability of each patient. As soon as each segmented delivery was completed, the beam interrupt button was pushed; subsequently, the patient was asked for free breathing. This procedure was repeated until all the segmented VMAT beams were delivered. A lung tumor case is reported here as an initial study. The proposed technique may be clinically advantageous for treating respiratory moving tumors including lung tumor, liver cancer, and other abdominal cancers.
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Affiliation(s)
| | - Yoko Taima
- Department of Radiation Oncology, Kanazawa University Hospital
| | | | | | - Koji Nobata
- Department of Radiology, Kouseiren Takaoka Hospital
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Bruza P, Andreozzi JM, Gladstone DJ, Jarvis LA, Rottmann J, Pogue BW. Online Combination of EPID & Cherenkov Imaging for 3-D Dosimetry in a Liquid Phantom. IEEE Trans Med Imaging 2017; 36:2099-2103. [PMID: 28644800 PMCID: PMC5659346 DOI: 10.1109/tmi.2017.2717800] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Online acquisition of Cherenkov and portal imaging data was combined with a reconstruction scheme called EC3-D, providing a full 3-D dosimetry of megavoltage X-ray beams in a water tank. The methodology was demonstrated and quantified in a single static beam. Furthermore, the dynamics and visualization of the 3-D dose reconstruction were demonstrated with a volumetric modulated arc therapy plan for TG-119 C-Shape geometry. The developed algorithm combines depth dose information, provided by Cherenkov images, with the lateral dose distribution, provided by the electronic portal imaging device. The strength of our approach lies in the acquisition of both imaging data streams with sub-millimeter theoretical resolution at 5-Hz frame-rate, which can be concurrently processed by the fast Fourier transform-based analysis, thus providing means for an efficient real-time 3-D dosimetry.
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Balaji Subramanian S, Balaji K, Thirunavukarasu M, Premkumar S. Bilateral Breast Irradiation Using Hybrid Volumetric Modulated Arc Therapy (h- VMAT) Technique: A Planning Case Report. Cureus 2016; 8:e914. [PMID: 28083458 PMCID: PMC5215817 DOI: 10.7759/cureus.914] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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] [Indexed: 12/25/2022] Open
Abstract
The purpose of this planning case report is to share the perceived dosimetric benefits of innovative hybrid volumetric modulated arc therapy (h-VMAT) for bilateral breast cancer radiotherapy in two patients with synchronous bilateral breast cancer. Two patients with early bilateral breast cancer after breast conservation surgery and adjuvant chemotherapy were planned for bilateral breast radiotherapy. On the planning computed tomography (CT) dataset, bilateral breast planning treatment volume (PTV) and organs at risk (OARs) were delineated using standard guidelines. Using the same structure set, volumetric modulated arc therapy (VMAT) and h-VMAT plans were generated and compared dosimetrically. The h-VMAT showed comparable target coverage, conformity and homogeneity while sparing of both lungs and heart were better. The dose to heart was reduced with h-VMAT, with a V25Gy and V5Gy of 3.2 & 22.3% for h-VMAT versus 11.6 & 84.9% for the VMAT plan. Similarly, the dose to the total lung was better in h-VMAT with a V20Gy and V5Gy of 12.1 & 46.2 versus 19.9 & 83.3% for VMAT. Overall the results indicate a better sparing of lung and heart at low doses with h-VMAT. Long-term clinical follow-up will give us more insight about the dosimetric benefits of these innovative techniques.
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16
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Miura H, Ozawa S, Hosono F, Sumida N, Okazue T, Yamada K, Nagata Y. Gafchromic EBT-XD film: Dosimetry characterization in high-dose, volumetric-modulated arc therapy. J Appl Clin Med Phys 2016; 17:312-322. [PMID: 27929504 PMCID: PMC5690510 DOI: 10.1120/jacmp.v17i6.6281] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [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: 12/27/2015] [Revised: 07/26/2016] [Accepted: 07/25/2016] [Indexed: 12/31/2022] Open
Abstract
Radiochromic films are important tools for assessing complex dose distributions. Gafchromic EBT-XD films have been designed for optimal performance in the 40-4,000 cGy dose range. We investigated the dosimetric characteristics of these films, including their dose-response, postexposure density growth, and dependence on scanner orientation, beam energy, and dose rate with applications to high-dose volumetric-modulated arc therapy (VMAT) verification. A 10 MV beam from a TrueBeam STx linear accelerator was used to irradiate the films with doses in the 0-4,000 cGy range. Postexposure coloration was analyzed at postirradiation times ranging from several minutes to 48 h. The films were also irradiated with 6 MV (dose rate (DR): 600 MU/min), 6 MV flattening filter-free (FFF) (DR: 1,400 MU/ min), and 10 MV FFF (DR: 2,400 MU/min) beams to determine the energy and dose-rate dependence. For clinical examinations, we compared the dose distribu-tion measured with EBT-XD films and calculated by the planning system for four VMAT cases. The red channel of the EBT-XD film exhibited a wider dynamic range than the green and blue channels. Scanner orientation yielded a variation of ~ 3% in the net optical density (OD). The difference between the film front and back scan orientations was negligible, with variation of ~ 1.3% in the net OD. The net OD increased sharply within the first 6 hrs after irradiation and gradually afterwards. No significant difference was observed for the beam energy and dose rate, with a variation of ~ 1.5% in the net OD. The gamma passing rates (at 3%, 3 mm) between the film- measured and treatment planning system (TPS)-calculated dose distributions under a high dose VMAT plan in the absolute dose mode were more than 98.9%.
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17
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Stang K, Alite F, Steber J, Emami B, Surucu M. Leukemia Cutis of the Face, Scalp, and Neck Treated with Non-coplanar Split Field Volumetric Modulated Arc Therapy: A Case Report. Cureus 2015; 7:e430. [PMID: 26848419 PMCID: PMC4727940 DOI: 10.7759/cureus.430] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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] [Indexed: 11/29/2022] Open
Abstract
Malignancies with a superficial involvement of the scalp present a unique technical challenge for radiation treatment planning. As an example of this, leukemic infiltration of the superficial skin as the only presentation of the disease is a rare entity. For such cases, radiation oncologists have typically treated with 3D conformal radiotherapy with matched electron fields, a technique that can lead to significant dose inhomogeneity. In this report, we describe the case of a patient with leukemia cutis with a superficial involvement of the scalp, face, and shoulders that was treated with volumetric modulated arc radiotherapy, with an impressive clinical response.
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Affiliation(s)
- Kyle Stang
- Department of Radiation Oncology, Loyola University of Chicago Stritch School of Medicine
| | - Fiori Alite
- Department of Radiation Oncology, Loyola University of Chicago Stritch School of Medicine
| | - Jennifer Steber
- Department of Radiation Oncology, Loyola University of Chicago Stritch School of Medicine
| | - Bahman Emami
- Department of Radiation Oncology, Loyola University of Chicago Stritch School of Medicine
| | - Murat Surucu
- Department of Radiation Oncology, Loyola University of Chicago Stritch School of Medicine
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18
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Unkelbach J, Bortfeld T, Craft D, Alber M, Bangert M, Bokrantz R, Chen D, Li R, Xing L, Men C, Nill S, Papp D, Romeijn E, Salari E. Optimization approaches to volumetric modulated arc therapy planning. Med Phys 2015; 42:1367-77. [PMID: 25735291 PMCID: PMC5148175 DOI: 10.1118/1.4908224] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [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: 11/07/2014] [Revised: 01/28/2015] [Accepted: 02/04/2015] [Indexed: 12/15/2022] Open
Abstract
Volumetric modulated arc therapy (VMAT) has found widespread clinical application in recent years. A large number of treatment planning studies have evaluated the potential for VMAT for different disease sites based on the currently available commercial implementations of VMAT planning. In contrast, literature on the underlying mathematical optimization methods used in treatment planning is scarce. VMAT planning represents a challenging large scale optimization problem. In contrast to fluence map optimization in intensity-modulated radiotherapy planning for static beams, VMAT planning represents a nonconvex optimization problem. In this paper, the authors review the state-of-the-art in VMAT planning from an algorithmic perspective. Different approaches to VMAT optimization, including arc sequencing methods, extensions of direct aperture optimization, and direct optimization of leaf trajectories are reviewed. Their advantages and limitations are outlined and recommendations for improvements are discussed.
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Affiliation(s)
- Jan Unkelbach
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Thomas Bortfeld
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - David Craft
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Markus Alber
- Department of Medical Physics and Department of Radiation Oncology, Aarhus University Hospital, Aarhus C DK-8000, Denmark
| | - Mark Bangert
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg D-69120, Germany
| | | | - Danny Chen
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana 46556
| | - Ruijiang Li
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
| | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
| | - Chunhua Men
- Department of Research, Elekta, Maryland Heights, Missouri 63043
| | - Simeon Nill
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG, United Kingdom
| | - Dávid Papp
- Department of Mathematics, North Carolina State University, Raleigh, North Carolina 27695
| | - Edwin Romeijn
- H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Ehsan Salari
- Department of Industrial and Manufacturing Engineering, Wichita State University, Wichita, Kansas 67260
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Bedford JL, Chajecka-Szczygielska H, Thomas MDR. Quality control of VMAT synchronization using portal imaging. J Appl Clin Med Phys 2015; 16:5238. [PMID: 25679179 PMCID: PMC5689994 DOI: 10.1120/jacmp.v16i1.5238] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [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: 07/30/2014] [Revised: 10/07/2014] [Accepted: 09/29/2014] [Indexed: 02/01/2023] Open
Abstract
For accurate delivery of volumetric-modulated arc therapy (VMAT), the gantry position should be synchronized with the multileaf collimator (MLC) leaf positions and the dose rate. This study, therefore, aims to implement quality control (QC) of VMAT synchronization, with as few arcs as possible and with minimal data handling time, using portal imaging. A steel bar of diameter 12 mm is accurately positioned in the G-T direction, 80 mm laterally from the isocenter. An arc prescription irradiates the bar with a 16 mm × 220 mm field during a complete 360° arc, so as to cast a shadow of the bar onto the portal imager. This results in a sinusoidal sweep of the field and shadow across the portal imager and back. The method is evaluated by simulating gantry position errors of 1°-9° at one control point, dose errors of 2 monitor units to 20 monitor units (MU) at one control point (0.3%-3% overall), and MLC leaf position errors of 1 mm - 6 mm at one control point. Inhomogeneity metrics are defined to characterize the synchronization of all leaves and of individual leaves with respect to the complete set. Typical behavior is also investigated for three models of accelerator. In the absence of simulated errors, the integrated images show uniformity, and with simulated delivery errors, irregular patterns appear. The inhomogeneity metrics increase by 67% due to a 4° gantry position error, 33% due to an 8 MU (1.25%) dose error, and 70% due to a 2 mm MLC leaf position error. The method is more sensitive to errors at gantry angle 90°/270° than at 0°/180° due to the geometry of the test. This method provides fast and effective VMAT QC suitable for inclusion in a monthly accelerator QC program. The test is able to detect errors in the delivery of individual control points, with the possibility of using movie images to further investigate suspicious image features.
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Abstract
BACKGROUND Gated Volumetric Modulated Arc Therapy (VMAT) is an emerging radiation therapy modality for treatment of tumors affected by respiratory motion. However, gating significantly prolongs the treatment time, as delivery is only activated during a single respiratory phase. To enhance the efficiency of gated VMAT delivery, a novel dual-gated VMAT (DG-VMAT) technique, in which delivery is executed at both exhale and inhale phases in a given arc rotation, is developed and experimentally evaluated. METHODS Arc delivery at two phases is realized by sequentially interleaving control points consisting of MUs, MLC sequences, and angles of VMAT plans generated at the exhale and inhale phases. Dual-gated delivery is initiated when a respiration gating signal enters the exhale window; when the exhale delivery concludes, the beam turns off and the gantry rolls back to the starting position for the inhale window. The process is then repeated until both inhale and exhale arcs are fully delivered. DG-VMAT plan delivery accuracy was assessed using a pinpoint chamber and diode array phantom undergoing programmed motion. RESULTS DG-VMAT delivery was experimentally implemented through custom XML scripting in Varian's TrueBeam™ STx Developer Mode. Relative to single gated delivery at exhale, the treatment time was improved by 95.5% for a sinusoidal breathing pattern. The pinpoint chamber dose measurement agreed with the calculated dose within 0.7%. For the DG-VMAT delivery, 97.5% of the diode array measurements passed the 3%/3 mm gamma criterion. CONCLUSIONS The feasibility of DG-VMAT delivery scheme has been experimentally demonstrated for the first time. By leveraging the stability and natural pauses that occur at end-inspiration and end-exhalation, DG-VMAT provides a practical method for enhancing gated delivery efficiency by up to a factor of two.
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Affiliation(s)
- Benjamin Fahimian
- />Department of Radiation Oncology, Stanford University, Stanford, CA USA
| | - Junqing Wu
- />Department of Radiation Oncology, Stanford University, Stanford, CA USA
- />School of Health Sciences, Purdue University, West Lafayette, IN USA
| | - Huanmei Wu
- />Purdue School of Engineering and Technology, Indiana University School of Informatics, IUPUI, Indianapolis, IN USA
| | - Sarah Geneser
- />Department of Radiation Oncology, Stanford University, Stanford, CA USA
| | - Lei Xing
- />Department of Radiation Oncology, Stanford University, Stanford, CA USA
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Grygoruk A, Chen A, Martin CA, Lawal HO, Fei H, Gutierrez G, Biedermann T, Najibi R, Hadi R, Chouhan AK, Murphy NP, Schweizer FE, Macleod GT, Maidment NT, Krantz DE. The redistribution of Drosophila vesicular monoamine transporter mutants from synaptic vesicles to large dense-core vesicles impairs amine-dependent behaviors. J Neurosci 2014; 34:6924-37. [PMID: 24828646 DOI: 10.1523/JNEUROSCI.0694-14.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Monoamine neurotransmitters are stored in both synaptic vesicles (SVs), which are required for release at the synapse, and large dense-core vesicles (LDCVs), which mediate extrasynaptic release. The contributions of each type of vesicular release to specific behaviors are not known. To address this issue, we generated mutations in the C-terminal trafficking domain of the Drosophila vesicular monoamine transporter (DVMAT), which is required for the vesicular storage of monoamines in both SVs and LDCVs. Deletion of the terminal 23 aa (DVMAT-Δ3) reduced the rate of endocytosis and localization of DVMAT to SVs, but supported localization to LDCVs. An alanine substitution mutation in a tyrosine-based motif (DVMAT-Y600A) also reduced sorting to SVs and showed an endocytic deficit specific to aminergic nerve terminals. Redistribution of DVMAT-Y600A from SV to LDCV fractions was also enhanced in aminergic neurons. To determine how these changes might affect behavior, we expressed DVMAT-Δ3 and DVMAT-Y600A in a dVMAT null genetic background that lacks endogenous dVMAT activity. When expressed ubiquitously, DVMAT-Δ3 showed a specific deficit in female fertility, whereas DVMAT-Y600A rescued behavior similarly to DVMAT-wt. In contrast, when expressed more specifically in octopaminergic neurons, both DVMAT-Δ3 and DVMAT-Y600A failed to rescue female fertility, and DVMAT-Y600A showed deficits in larval locomotion. DVMAT-Y600A also showed more severe dominant effects than either DVMAT-wt or DVMAT-Δ3. We propose that these behavioral deficits result from the redistribution of DVMAT from SVs to LDCVs. By extension, our data suggest that the balance of amine release from SVs versus that from LDCVs is critical for the function of some aminergic circuits.
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Klein J, Dawson LA, Tran TH, Adeyi O, Purdie T, Sherman M, Brade A. Metabolic syndrome-related hepatocellular carcinoma treated by volumetric modulated arc therapy. ACTA ACUST UNITED AC 2014; 21:e340-4. [PMID: 24764717 DOI: 10.3747/co.21.1756] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hepatocellular carcinoma (hcc) is a leading cause of cancer mortality, and its incidence is increasing in developed countries. Risk factors include cirrhosis from viral hepatitis or alcohol abuse. Metabolic syndrome is a newly recognized, but important, risk factor that is likely contributing to the increased incidence of hcc. Surgery is the therapy of choice for hcc, but local therapies are often contraindicated, usually because of advanced disease or comorbid conditions such as cardiac disease (which is associated with metabolic syndrome). Current radiation therapy techniques such as stereotactic body radiotherapy allow for treatment plans that highly conform to the target and provide excellent sparing of normal structures. Radiation therapy is emerging as a viable option in patients not eligible for surgery or other locoregional therapies. Here, we report a case of a large hcc presenting in a patient with metabolic syndrome without significant alcohol history or biochemical liver dysfunction. The patient was not a candidate for locoregional therapies because of cardiac and renal comorbidities typical of patients experiencing the long-term sequelae of metabolic syndrome. Treatment using an arc-based volumetric-modulated arc therapy technique allowed for the highest dose of radiation to be delivered to the tumour while the peripheral radiation dose was minimized. A complete local response was confirmed by computed tomography imaging 21 months after treatment completion.
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Affiliation(s)
- J Klein
- Department of Radiation Oncology, University of Toronto, Princess Margaret Hospital, Toronto, ON
| | - L A Dawson
- Department of Radiation Oncology, University of Toronto, Princess Margaret Hospital, Toronto, ON
| | - T H Tran
- Department of Radiation Oncology, University of Toronto, Princess Margaret Hospital, Toronto, ON
| | - O Adeyi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto General Hospital, Toronto, ON
| | - T Purdie
- Department of Radiation Oncology, University of Toronto, Princess Margaret Hospital, Toronto, ON
| | - M Sherman
- Department of Medicine, University of Toronto, University Health Network, Toronto, ON
| | - A Brade
- Department of Radiation Oncology, University of Toronto, Princess Margaret Hospital, Toronto, ON
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Lin H, Huang S, Deng X, Zhu J, Chen L. Comparison of 3D anatomical dose verification and 2D phantom dose verification of IMRT/ VMAT treatments for nasopharyngeal carcinoma. Radiat Oncol 2014; 9:71. [PMID: 24606879 PMCID: PMC4014203 DOI: 10.1186/1748-717x-9-71] [Citation(s) in RCA: 10] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/02/2014] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The two-dimensional phantom dose verification (2D-PDV) using hybrid plan and planar dose measurement has been widely used for IMRT treatment QA. Due to the lack of information about the correlations between the verification results and the anatomical structure of patients, it is inadequate in clinical evaluation. A three-dimensional anatomical dose verification (3D-ADV) method was used in this study to evaluate the IMRT/VMAT treatment delivery for nasopharyngeal carcinoma and comparison with 2D-PDV was analyzed. METHODS Twenty nasopharyngeal carcinoma (NPC) patients treated with IMRT/VMAT were recruited in the study. A 2D ion-chamber array was used for the 2D-PDV in both single-gantry-angle composite (SGAC) and multi-gantry-angle composite (MGAC) verifications. Differences in the gamma pass rate between the 2 verification methods were assessed. Based on measurement of irradiation dose fluence, the 3D dose distribution was reconstructed for 3D-ADV in the above cases. The reconstructed dose homogeneity index (HI), conformity index (CI) of the planning target volume (PTV) were calculated. Gamma pass rate and deviations in the dose-volume histogram (DVH) of each PTV and organ at risk (OAR) were analyzed. RESULTS In 2D-PDV, the gamma pass rate (3%, 3 mm) of SGAC (99.55% ± 0.83%) was significantly higher than that of MGAC (92.41% ± 7.19%). In 3D-ADV, the gamma pass rates (3%, 3 mm) were 99.75% ± 0.21% in global, 83.82% ± 16.98% to 93.71% ± 6.22% in the PTVs and 45.12% ± 32.78% to 98.08% ± 2.29% in the OARs. The maximum HI increment in PTVnx was 19.34%, while the maximum CI decrement in PTV1 and PTV2 were -32.45% and -6.93%, respectively. Deviations in dose volume of PTVs were all within ±5%. D2% of the brainstem, spinal cord, left/right optic nerves, and the mean doses to the left/right parotid glands maximally increased by 3.5%, 6.03%, 31.13%/26.90% and 4.78%/4.54%, respectively. CONCLUSION The 2D-PDV and global gamma pass rate might be insufficient to provide an accurate assessment for the complex NPC IMRT operation. In contrast, the 3D-ADV is superior in clinic-related quality assurance offering evaluation of organ specific pass rate and dose-volume deviations.
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Affiliation(s)
- Hailei Lin
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
- Department of Radiation Oncology, Beijing Hospital of the Ministry of Health, Beijing 100730, China
| | - Shaomin Huang
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - Xiaowu Deng
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - Jinhan Zhu
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
- School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Lixin Chen
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
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Lawal HO, Terrell A, Lam HA, Djapri C, Jang J, Hadi R, Roberts L, Shahi V, Chou MT, Biedermann T, Huang B, Lawless GM, Maidment NT, Krantz DE. Drosophila modifier screens to identify novel neuropsychiatric drugs including aminergic agents for the possible treatment of Parkinson's disease and depression. Mol Psychiatry 2014; 19:235-42. [PMID: 23229049 PMCID: PMC3610854 DOI: 10.1038/mp.2012.170] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 08/21/2012] [Accepted: 09/17/2012] [Indexed: 01/05/2023]
Abstract
Small molecules that increase the presynaptic function of aminergic cells may provide neuroprotection in Parkinson's disease (PD) as well as treatments for attention deficit hyperactivity disorder (ADHD) and depression. Model genetic organisms such as Drosophila melanogaster may enhance the detection of new drugs via modifier or 'enhancer/suppressor' screens, but this technique has not been applied to processes relevant to psychiatry. To identify new aminergic drugs in vivo, we used a mutation in the Drosophila vesicular monoamine transporter (dVMAT) as a sensitized genetic background and performed a suppressor screen. We fed dVMAT mutant larvae ∼ 1000 known drugs and quantitated rescue (suppression) of an amine-dependent locomotor deficit in the larva. To determine which drugs might specifically potentiate neurotransmitter release, we performed an additional secondary screen for drugs that require presynaptic amine storage to rescue larval locomotion. Using additional larval locomotion and adult fertility assays, we validated that at least one compound previously used clinically as an antineoplastic agent potentiates the presynaptic function of aminergic circuits. We suggest that structurally similar agents might be used to development treatments for PD, depression and ADHD, and that modifier screens in Drosophila provide a new strategy to screen for neuropsychiatric drugs. More generally, our findings demonstrate the power of physiologically based screens for identifying bioactive agents for select neurotransmitter systems.
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Affiliation(s)
- Hakeem O. Lawal
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Ashley Terrell
- Department of Biological Sciences, University of Minnesota, Minneapolis MN, 55455 USA
| | - Hoa A. Lam
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Christine Djapri
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Jennifer Jang
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Richard Hadi
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Logan Roberts
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Varun Shahi
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Man-Ting Chou
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Traci Biedermann
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - Brian Huang
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | | | - Nigel T. Maidment
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA
| | - David E. Krantz
- Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095 USA,Corresponding Author: tel. 1 310 206 8508, fax 1 310 206 9877,
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Hussein M, Adams EJ, Jordan TJ, Clark CH, Nisbet A. A critical evaluation of the PTW 2D-ARRAY seven29 and OCTAVIUS II phantom for IMRT and VMAT verification. J Appl Clin Med Phys 2013; 14:4460. [PMID: 24257288 PMCID: PMC5714639 DOI: 10.1120/jacmp.v14i6.4460] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [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: 03/17/2013] [Revised: 06/18/2013] [Accepted: 06/17/2013] [Indexed: 12/25/2022] Open
Abstract
Quality assurance (QA) for intensity- and volumetric-modulated radiotherapy (IMRT and VMAT) has evolved substantially. In recent years, various commercial 2D and 3D ionization chamber or diode detector arrays have become available, allowing for absolute verification with near real time results, allowing for streamlined QA. However, detector arrays are limited by their resolution, giving rise to concerns about their sensitivity to errors. Understanding the limitations of these devices is therefore critical. In this study, the sensitivity and resolution of the PTW 2D-ARRAY seven29 and OCTAVIUS II phantom combination was comprehensively characterized for use in dynamic sliding window IMRT and RapidArc verification. Measurement comparisons were made between single acquisition and a multiple merged acquisition techniques to improve the effective resolution of the 2D-ARRAY, as well as comparisons against GAFCHROMIC EBT2 film and electronic portal imaging dosimetry (EPID). The sensitivity and resolution of the 2D-ARRAY was tested using two gantry angle 0° modulated test fields. Deliberate multileaf collimator (MLC) errors of 1, 2, and 5 mm and collimator rotation errors were inserted into IMRT and RapidArc plans for pelvis and head & neck sites, to test sensitivity to errors. The radiobiological impact of these errors was assessed to determine the gamma index passing criteria to be used with the 2D-ARRAY to detect clinically relevant errors. For gamma index distributions, it was found that the 2D-ARRAY in single acquisition mode was comparable to multiple acquisition modes, as well as film and EPID. It was found that the commonly used gamma index criteria of 3% dose difference or 3 mm distance to agreement may potentially mask clinically relevant errors. Gamma index criteria of 3%/2 mm with a passing threshold of 98%, or 2%/2 mm with a passing threshold of 95%, were found to be more sensitive. We suggest that the gamma index passing thresholds may be used for guidance, but also should be combined with a visual inspection of the gamma index distribution and calculation of the dose difference to assess whether there may be a clinical impact in failed regions.
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Affiliation(s)
- Mohammad Hussein
- Royal Surrey County Hospital NHS Foundation Trust, University of Surrey.
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Kroon PS, Hol S, Essers M. Dosimetric accuracy and clinical quality of Acuros XB and AAA dose calculation algorithm for stereotactic and conventional lung volumetric modulated arc therapy plans. Radiat Oncol 2013; 8:149. [PMID: 23800024 PMCID: PMC3723919 DOI: 10.1186/1748-717x-8-149] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [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: 02/08/2013] [Accepted: 06/03/2013] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION The main aim of the current study was to assess the dosimetric accuracy and clinical quality of volumetric modulated arc therapy (VMAT) plans for stereotactic (stage I) and conventional (stage III) lung cancer treatments planned with Eclipse version 10.0 Anisotropic Analytical Algorithm (AAA) and Acuros XB (AXB) algorithm. METHODS The dosimetric impact of using AAA instead of AXB, and grid size 2.5 mm instead of 1.0 mm for VMAT treatment plans was evaluated. The clinical plan quality of AXB VMAT was assessed using 45 stage I and 73 stage III patients, and was compared with published results, planned with VMAT and hybrid-VMAT techniques. RESULTS The dosimetric impact on near-minimum PTV dose (D98%) using AAA instead of AXB was large (underdose up to 12.3%) for stage I and very small (underdose up to 0.8%) for stage III lung treatments. There were no significant differences for dose volume histogram (DVH) values between grid sizes. The calculation time was significantly higher for AXB grid size 1.0 than 2.5 mm (p < 0.01). The clinical quality of the VMAT plans was at least comparable with clinical qualities given in literature of lung treatment plans with VMAT and hybrid-VMAT techniques. The average mean lung dose (MLD), lung V(20Gy) and V(5Gy) in this study were respectively 3.6 Gy, 4.1% and 15.7% for 45 stage I patients and 12.4 Gy, 19.3% and 46.6% for 73 stage III lung patients. The average contra-lateral lung dose V(5Gy-cont) was 35.6% for stage III patients. CONCLUSIONS For stereotactic and conventional lung treatments, VMAT calculated with AXB grid size 2.5 mm resulted in accurate dose calculations. No hybrid technique was needed to obtain the dose constraints. AXB is recommended instead of AAA for avoiding serious overestimation of the minimum target doses compared to the actual delivered dose.
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Affiliation(s)
- Petra S Kroon
- Department of Medical Physics, Institute Verbeeten, Brugstraat 10, 5042 SB Tilburg, the Netherlands
| | - Sandra Hol
- Department of Radiotherapy, Institute Verbeeten, Brugstraat 10, 5042 SB Tilburg, the Netherlands
| | - Marion Essers
- Department of Medical Physics, Institute Verbeeten, Brugstraat 10, 5042 SB Tilburg, the Netherlands
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Han T, Followill D, Mikell J, Repchak R, Molineu A, Howell R, Salehpour M, Mourtada F. Dosimetric impact of Acuros XB deterministic radiation transport algorithm for heterogeneous dose calculation in lung cancer. Med Phys 2013; 40:051710. [PMID: 23635258 PMCID: PMC3651262 DOI: 10.1118/1.4802216] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [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: 01/03/2013] [Revised: 03/21/2013] [Accepted: 04/05/2013] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The novel deterministic radiation transport algorithm, Acuros XB (AXB), has shown great potential for accurate heterogeneous dose calculation. However, the clinical impact between AXB and other currently used algorithms still needs to be elucidated for translation between these algorithms. The purpose of this study was to investigate the impact of AXB for heterogeneous dose calculation in lung cancer for intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT). METHODS The thorax phantom from the Radiological Physics Center (RPC) was used for this study. IMRT and VMAT plans were created for the phantom in the Eclipse 11.0 treatment planning system. Each plan was delivered to the phantom three times using a Varian Clinac iX linear accelerator to ensure reproducibility. Thermoluminescent dosimeters (TLDs) and Gafchromic EBT2 film were placed inside the phantom to measure delivered doses. The measurements were compared with dose calculations from AXB 11.0.21 and the anisotropic analytical algorithm (AAA) 11.0.21. Two dose reporting modes of AXB, dose-to-medium in medium (Dm,m) and dose-to-water in medium (Dw,m), were studied. Point doses, dose profiles, and gamma analysis were used to quantify the agreement between measurements and calculations from both AXB and AAA. The computation times for AAA and AXB were also evaluated. RESULTS For the RPC lung phantom, AAA and AXB dose predictions were found in good agreement to TLD and film measurements for both IMRT and VMAT plans. TLD dose predictions were within 0.4%-4.4% to AXB doses (both Dm,m and Dw,m); and within 2.5%-6.4% to AAA doses, respectively. For the film comparisons, the gamma indexes (± 3%∕3 mm criteria) were 94%, 97%, and 98% for AAA, AXB_Dm,m, and AXB_Dw,m, respectively. The differences between AXB and AAA in dose-volume histogram mean doses were within 2% in the planning target volume, lung, heart, and within 5% in the spinal cord. However, differences up to 8% between AXB and AAA were found at lung∕soft tissue interface regions for individual IMRT fields. AAA was found to be 5-6 times faster than AXB for IMRT, while AXB was 4-5 times faster than AAA for VMAT plan. CONCLUSIONS AXB is satisfactorily accurate for the dose calculation in lung cancer for both IMRT and VMAT plans. The differences between AXB and AAA are generally small except in heterogeneous interface regions. AXB Dw,m and Dm,m calculations are similar inside the soft tissue and lung regions. AXB can benefit lung VMAT plans by both improving accuracy and reducing computation time.
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Affiliation(s)
- Tao Han
- Department of Radiation Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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Kim DW, Chung WK, Shin D, Hong S, Park SH, Park SY, Chung K, Lim YK, Shin D, Lee SB, Lee HH, Yoon M. Risk of second cancer from scattered radiation of intensity-modulated radiotherapies with lung cancer. Radiat Oncol 2013; 8:47. [PMID: 23452670 PMCID: PMC3599921 DOI: 10.1186/1748-717x-8-47] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [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: 12/24/2012] [Accepted: 02/24/2013] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To compare the risk of secondary cancer from scattered and leakage doses following intensity-modulated radiotherapy (IMRT), volumetric arc therapy (VMAT) and tomotherapy (TOMO) in patients with lung cancer. METHODS IMRT, VMAT and TOMO were planned for five lung cancer patients. Organ equivalent doses (OEDs) are estimated from the measured corresponding secondary doses during irradiation at various points 20 to 80 cm from the iso-center by using radio-photoluminescence glass dosimeter (RPLGD). RESULTS The secondary dose per Gy from IMRT, VMAT and TOMO for lung cancer, measured 20 to 80 cm from the iso-center, are 0.02~2.03, 0.03~1.35 and 0.04~0.46 cGy, respectively. The mean values of relative OED of secondary dose of VMAT and TOMO, which is normalized by IMRT, ranged between 88.63% and 41.59% revealing 88.63% and 41.59% for thyroid, 82.33% and 41.85% for pancreas, 77.97% and 49.41% for bowel, 73.42% and 72.55% for rectum, 74.16% and 81.51% for prostate. The secondary dose and OED from TOMO became similar to those from IMRT and VMAT as the distance from the field edge increased. CONCLUSIONS OED based estimation suggests that the secondary cancer risk from TOMO is less than or comparable to the risks from conventional IMRT and VMAT.
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Affiliation(s)
- Dong Wook Kim
- Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Seoul, Korea
| | - Weon Kuu Chung
- Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Seoul, Korea
| | - Dongoh Shin
- Department of Radiation Oncology, Kyung Hee University Medical Center, Seoul, Korea
| | - Seongeon Hong
- Department of Radiation Oncology, Kyung Hee University Medical Center, Seoul, Korea
| | - Sung Ho Park
- Department of medical Physics, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea
| | - Sung-Yong Park
- Proton Therapy Center, McLaren Cancer Institute, Flint, USA
| | - Kwangzoo Chung
- Proton Therapy Center, National Cancer Center, Ilsan, Korea
| | | | - Dongho Shin
- Proton Therapy Center, National Cancer Center, Ilsan, Korea
| | - Se Byeong Lee
- Proton Therapy Center, National Cancer Center, Ilsan, Korea
| | - Hyun-ho Lee
- Department of Radiological Science, College of Health Science, Korea University, Jeongneung 3-dong, Seongbuk-gu, Seoul, Korea
| | - Myonggeun Yoon
- Department of Radiological Science, College of Health Science, Korea University, Jeongneung 3-dong, Seongbuk-gu, Seoul, Korea
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Yang K, Yan D, Tyagi N. Sensitivity analysis of physics and planning SmartArc parameters for single and partial arc VMAT planning. J Appl Clin Med Phys 2012; 13:3760. [PMID: 23149771 PMCID: PMC5718532 DOI: 10.1120/jacmp.v13i6.3760] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [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: 09/08/2011] [Revised: 05/30/2012] [Accepted: 06/25/2012] [Indexed: 12/02/2022] Open
Abstract
We investigate the sensitivity of various physics and planning SmartArc parameters to generate single and partial arc VMAT plans with equivalent or better plan quality as IMRT. Patients previously treated with step-and-shoot IMRT for several treatment sites were replanned using SmartArc. These treatment sites included head and neck, prostate, lung, and spine. Effect of various physics and planning SmartArc parameters, such as continuous vs. binned dose rate, dynamic leaf gap, leaf speed, maximum delivery time, number of arcs, and control point spacing, were investigated for Elekta Axesse and Synergy linacs. Absolute dose distribution was measured by using the ArcCHECK 3D cylindrical diode array. For all cases investigated, plan metrics such as conformity indices and dose homogeneity indices increased, while plan QA decreased with increasing leaf speed. Leaf speed had a significant impact on the segment size for low dose per fractionation cases. Constraining leaf motion to a lower speed not only avoids tiny large leaf travel and low-dose rate value, but also achieves better PTV coverage (defined as the volume receiving prescription dose) with less total MUs. Maximum delivery time, the number of arcs, and the spacing of control points all had similar effects as the leaf motion constraint on dose rate and segment size. The maximum delivery time had a significant effect on the optimization, acting as a hard constraint. Increasing the control point spacing from 2 to 6 degrees increased the PTV coverage, but reduced the absolute dose gamma passing rate. Plans generated using continuous and binned dose rate modes did not show any difference in the quality and the delivery for the Elekta machines. Dosimetric analysis with a 3D cylindrical QA phantom resulted in 93.6%-99.3% of detectors with a gamma index (3%/2 mm) < 1 for all cases.
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Affiliation(s)
- Kai Yang
- Department of Radiation OncologyWilliam Beaumont HospitalRoyal OakMIUSA
| | - Di Yan
- Department of Radiation OncologyWilliam Beaumont HospitalRoyal OakMIUSA
| | - Neelam Tyagi
- Department of Radiation OncologyWilliam Beaumont HospitalRoyal OakMIUSA
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Nakagawa K, Kida S, Haga A, Masutani Y, Yamashita H, Onoe T, Imae T, Tanaka K, Ohtomo K, Yoda K. 4D digitally reconstructed radiography for verifying a lung tumor position during volumetric modulated arc therapy. J Radiat Res 2012; 53:628-32. [PMID: 22843630 PMCID: PMC3393348 DOI: 10.1093/jrr/rrs013] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We have proposed four dimensional (4D) digitally reconstructed radiography (DRR) for verifying a lung tumor position during volumetric modulated arc therapy (VMAT). An internal target volume (ITV) was defined based on two clinical target volumes (CTVs) delineated on maximum exhalation and maximum inhalation images acquired by 4D planning computed tomography (CT). A planning target volume (PTV) was defined by adding a margin of 5 mm to the ITV on the maximum exhalation 3D CT images. A single-arc VMAT plan was created on the same CT data using Pinnacle SmartArc with a maximum multi-leaf collimator leaf speed of 1 mm/degree, thereby resulting in quasi-conformal field shapes while optimizing each beam intensity for each gantry angle. During VMAT delivery, cone-beam CT (CBCT) projection data were acquired by an on-board kilovoltage X-ray unit and a flat panel 2D detector. Four CBCT image sets with different respiratory phases were reconstructed using in-house software, where respiratory phases were extracted from the projection data. Subsequently a CTV was delineated on each of the 4D CBCT images by an oncologist. Using the resulting 4D CBCT data including the CTV contours, 4D DRRs during the VMAT delivery were calculated as a function of gantry angle. It was confirmed that the contoured CTV was within the radiation field during the four-fraction lung VMAT delivery. The proposed 4D DRR may facilitate the verification of the position of a respiratory moving lung tumor during VMAT delivery on each treatment day.
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Affiliation(s)
- Keiichi Nakagawa
- Department of Radiology, University of Tokyo Hospital, 7-3-1 Hongo Bunkyo-ku, Tokyo, Japan.
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Han T, Mourtada F, Kisling K, Mikell J, Followill D, Howell R. Experimental validation of deterministic Acuros XB algorithm for IMRT and VMAT dose calculations with the Radiological Physics Center's head and neck phantom. Med Phys 2012; 39:2193-202. [PMID: 22482641 PMCID: PMC3337663 DOI: 10.1118/1.3692180] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [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: 10/31/2011] [Revised: 01/09/2012] [Accepted: 02/14/2012] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this study was to verify the dosimetric performance of Acuros XB (AXB), a grid-based Boltzmann solver, in intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT). METHODS The Radiological Physics Center (RPC) head and neck (H&N) phantom was used for all calculations and measurements in this study. Clinically equivalent IMRT and VMAT plans were created on the RPC H&N phantom in the Eclipse treatment planning system (version 10.0) by using RPC dose prescription specifications. The dose distributions were calculated with two different algorithms, AXB 11.0.03 and anisotropic analytical algorithm (AAA) 10.0.24. Two dose report modes of AXB were recorded: dose-to-medium in medium (D(m,m)) and dose-to-water in medium (D(w,m)). Each treatment plan was delivered to the RPC phantom three times for reproducibility by using a Varian Clinac iX linear accelerator. Absolute point dose and planar dose were measured with thermoluminescent dosimeters (TLDs) and GafChromic® EBT2 film, respectively. Profile comparison and 2D gamma analysis were used to quantify the agreement between the film measurements and the calculated dose distributions from both AXB and AAA. The computation times for AAA and AXB were also evaluated. RESULTS Good agreement was observed between measured doses and those calculated with AAA or AXB. Both AAA and AXB calculated doses within 5% of TLD measurements in both the IMRT and VMAT plans. Results of AXB_D(m,m) (0.1% to 3.6%) were slightly better than AAA (0.2% to 4.6%) or AXB_D(w,m) (0.3% to 5.1%). The gamma analysis for both AAA and AXB met the RPC 7%/4 mm criteria (over 90% passed), whereas AXB_D(m,m) met 5%/3 mm criteria in most cases. AAA was 2 to 3 times faster than AXB for IMRT, whereas AXB was 4-6 times faster than AAA for VMAT. CONCLUSIONS AXB was found to be satisfactorily accurate when compared to measurements in the RPC H&N phantom. Compared with AAA, AXB results were equal to or better than those obtained with film measurements for IMRT and VMAT plans. The AXB_D(m,m) reporting mode was found to be closer to TLD and film measurements than was the AXB_D(w,m) mode. AXB calculation time was found to be significantly shorter (× 4) than AAA for VMAT.
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Affiliation(s)
- Tao Han
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Hardcastle N, Tomé WA, Foo K, Miller A, Carolan M, Metcalfe P. Comparison of prostate IMRT and VMAT biologically optimised treatment plans. Med Dosim 2010; 36:292-8. [PMID: 20801014 PMCID: PMC2995847 DOI: 10.1016/j.meddos.2010.06.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [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: 10/08/2009] [Revised: 05/13/2010] [Accepted: 06/10/2010] [Indexed: 11/18/2022]
Abstract
Recently, a new radiotherapy delivery technique has become clinically available--volumetric modulated arc therapy (VMAT). VMAT is the delivery of IMRT while the gantry is in motion using dynamic leaf motion. The perceived benefit of VMAT over IMRT is a reduction in delivery time. In this study, VMAT was compared directly with IMRT for a series of prostate cases. For 10 patients, a biologically optimized seven-field IMRT plan was compared with a biologically optimized VMAT plan using the same planning objectives. The Pinnacle RTPS was used. The resultant target and organ-at-risk dose-volume histograms (DVHs) were compared. The normal tissue complication probability (NTCP) for the IMRT and VMAT plans was calculated for 3 model parameter sets. The delivery efficiency and time for the IMRT and VMAT plans was compared. The VMAT plans resulted in a statistically significant reduction in the rectal V25Gy parameter of 8.2% on average over the IMRT plans. For one of the NTCP parameter sets, the VMAT plans had a statistically significant lower rectal NTCP. These reductions in rectal dose were achieved using 18.6% fewer monitor units and a delivery time reduction of up to 69%. VMAT plans resulted in reductions in rectal doses for all 10 patients in the study. This was achieved with significant reductions in delivery time and monitor units. Given the target coverage was equivalent, the VMAT plans were superior.
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Affiliation(s)
- Nicholas Hardcastle
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia.
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Lee WY, Chang JW, Nemeth NL, Kang UJ. Vesicular monoamine transporter-2 and aromatic L-amino acid decarboxylase enhance dopamine delivery after L-3, 4-dihydroxyphenylalanine administration in Parkinsonian rats. J Neurosci 1999; 19:3266-74. [PMID: 10191339 PMCID: PMC6782290] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Medical therapy in Parkinson's disease (PD) is limited by the short-duration response and development of dyskinesia that result from chronic L-3,4-dihydroxyphenylalanine (L-DOPA) therapy. These problems occur partly because the loss of dopamine storage sites leads to erratic dopamine delivery. Vesicular monoamine transporter-2 (VMAT-2) plays a critical role in dopamine storage by packaging dopamine into synaptic vesicles and regulating sustained release of dopamine. To restore the capacity to produce and store dopamine in parkinsonian rats, primary skin fibroblast cells (PF) were genetically modified with aromatic L-amino acid decarboxylase (AADC) and VMAT-2 genes. After incubation with L-DOPA in culture, the doubly transduced fibroblast cells (PFVMAA) produced and stored dopamine at a much higher level than the cells with either gene alone. PFVMAA cells in culture released dopamine gradually in a constitutive manner. Genetically modified fibroblast cells were grafted in parkinsonian rat striata, and L-DOPA was systemically administered. Higher dopamine levels were sustained for a longer duration in rats grafted with PFVMAA cells than in those grafted with either control cells or cells with AADC alone. These findings underscore the importance of dopamine storage capacity in determining the efficacy of L-DOPA therapy and illustrate a novel method of gene therapy combined with precursor administration to overcome the major obstacles of PD treatment.
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Affiliation(s)
- W Y Lee
- Department of Neurology, The University of Chicago, Chicago, Illinois 60637, USA
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Duerr JS, Frisby DL, Gaskin J, Duke A, Asermely K, Huddleston D, Eiden LE, Rand JB. The cat-1 gene of Caenorhabditis elegans encodes a vesicular monoamine transporter required for specific monoamine-dependent behaviors. J Neurosci 1999; 19:72-84. [PMID: 9870940 PMCID: PMC6782383] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
We have identified the Caenorhabditis elegans homolog of the mammalian vesicular monoamine transporters (VMATs); it is 47% identical to human VMAT1 and 49% identical to human VMAT2. C. elegans VMAT is associated with synaptic vesicles in approximately 25 neurons, including all of the cells reported to contain dopamine and serotonin, plus a few others. When C. elegans VMAT is expressed in mammalian cells, it has serotonin and dopamine transport activity; norepinephrine, tyramine, octopamine, and histamine also have high affinity for the transporter. The pharmacological profile of C. elegans VMAT is closer to mammalian VMAT2 than VMAT1. The C. elegans VMAT gene is cat-1; cat-1 knock-outs are totally deficient for VMAT immunostaining and for dopamine-mediated sensory behaviors, yet they are viable and grow relatively well. The cat-1 mutant phenotypes can be rescued by C. elegans VMAT constructs and also (at least partially) by human VMAT1 or VMAT2 transgenes. It therefore appears that the function of amine neurotransmitters can be completely dependent on their loading into synaptic vesicles.
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Affiliation(s)
- J S Duerr
- Program in Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
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Pothos EN, Davila V, Sulzer D. Presynaptic recording of quanta from midbrain dopamine neurons and modulation of the quantal size. J Neurosci 1998; 18:4106-18. [PMID: 9592091 PMCID: PMC6792796] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/1998] [Revised: 03/13/1998] [Accepted: 03/24/1998] [Indexed: 02/07/2023] Open
Abstract
The observation of quantal release from central catecholamine neurons has proven elusive because of the absence of evoked rapid postsynaptic currents. We adapted amperometric methods to observe quantal release directly from axonal varicosities of midbrain dopamine neurons that predominantly contain small synaptic vesicles. Quantal events were elicited by high K+ or alpha-latrotoxin, required extracellular Ca2+, and were abolished by reserpine. The events indicated the release of 3000 molecules over 200 microsec, much smaller and faster events than quanta associated with large dense-core vesicles previously recorded in vertebrate preparations. The number of dopamine molecules per quantum increased as a population to 380% of controls after glial-derived neurotrophic factor (GDNF) exposure and to 350% of controls after exposure to the dopamine precursor L-dihydroxyphenylalanine (L-DOPA). These results introduce a means to measure directly the number of transmitter molecules released from small synaptic vesicles of CNS neurons. Moreover, quantal size was not an invariant parameter in CNS neurons but could be modulated by neurotrophic factors and altered neurotransmitter synthesis.
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Affiliation(s)
- E N Pothos
- Department of Neurology, Columbia University, New York, New York 10032, USA
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