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Hanada T, Fukada J, Shiraishi Y, Yoshida K, Sakanoue N, Oguma K, Ohashi T, Shigematsu N. A rare instance of latent systematic error in volumetric-modulated arc therapy with field-extended multi-isocentre irradiation leading to a serious dose-delivery accident. BJR Case Rep 2024; 10:uaae021. [PMID: 39027402 PMCID: PMC11257714 DOI: 10.1093/bjrcr/uaae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 05/25/2024] [Accepted: 06/21/2024] [Indexed: 07/20/2024] Open
Abstract
Volumetric-modulated arc therapy (VMAT) with field-extended multi-isocentre irradiation (VMAT-FEMII) is an effective irradiation technique, particularly for large planning target volumes in the craniocaudal direction. A variety of treatment planning techniques have been reported to reduce the dosimetric impact. However, there is no guarantee that unexpected latent systematic errors would not occur. Herein, we report the experience with a rare case that could have led to a serious VMAT-FEMII-related accident. A patient with uterine cervical carcinoma was scheduled for VMAT-FEMII to the whole pelvis and the para-aortic lymph node region. A combination of the two sets of field groups with different isocentres was planned: one to cover the para-aortic lymph nodes and the other to cover the whole pelvis. Measurements based on the pretreatment dose delivery quality assurance (QA) revealed an unexpected overdose of >20% in the field overlap region. This overdose phenomenon is not reflected in the calculated dose distribution in the radiotherapy treatment planning system. Therefore, the plan was altered; a homogeneous dose distribution inside the dose junction was achieved. Several analyses were performed to elucidate the overdosing phenomenon. However, no conclusive answer was found to why non-reflection at the calculated dose distribution was found. The limitations to VMAT-FEMII are primarily related to systematic errors in the positional setup from patient-derived and/or mechanical sources. However, this report highlights a rare case of overdosing caused by inverse optimization and dose calculation. We recommend checking the aperture status of the jaw and multi-leaf collimator at each control point of the treatment plan and using a high-resolution image measurement system on a VMAT-FEMII QA to confirm the dose junction status.
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Affiliation(s)
- Takashi Hanada
- Department of Radiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Junichi Fukada
- Department of Radiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Yutaka Shiraishi
- Department of Radiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kayo Yoshida
- Department of Radiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Naoya Sakanoue
- Department of Radiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kohei Oguma
- Cancer Center (Radiotherapy Unit), Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Toshio Ohashi
- Department of Radiation Oncology, Tokyo Saiseikai Central Hospital, Tokyo 180-0073, Japan
| | - Naoyuki Shigematsu
- Department of Radiology, Keio University School of Medicine, Tokyo 160-8582, Japan
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Zhang Y, Huang Y, Lin J, Ding S, Gong X, Liu Q, Gong C. Multi-isocenter VMAT craniospinal irradiation using feasibility dose-volume histogram-guided auto-planning technique. JOURNAL OF RADIATION RESEARCH 2023:7150737. [PMID: 37141634 DOI: 10.1093/jrr/rrad026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/07/2022] [Indexed: 05/06/2023]
Abstract
This study aims to propose a novel treatment planning methodology for multi-isocenter volumetric modulated arc therapy (VMAT) craniospinal irradiation (CSI) using the special feasibility dose-volume histogram (FDVH)-guided auto-planning (AP) technique. Three different multi-isocenter VMAT -CSI plans were created, including manually based plans (MUPs), conventional AP plans (CAPs) and FDVH-guided AP plans (FAPs). The CAPs and FAPs were specially designed by combining multi-isocenter VMAT and AP techniques in the Pinnacle treatment planning system. Specially, the personalized optimization parameters for FAPs were generated using the FDVH function implemented in PlanIQ software, which provides the ideal organs at risk (OARs) sparing for the specific anatomical geometry based on the valuable assumption of the dose fall-off. Compared to MUPs, CAPs and FAPs significantly reduced the dose for most of the OARs. FAPs achieved the best homogeneity index (0.092 ± 0.013) and conformity index (0.980 ± 0.011), while CAPs were slightly inferior to the FAPs but superior to the MUPs. As opposed to MUPs, FAPs delivered a lower dose to OARs, whereas the difference between FAPs and CAPs was not statistically significant except for the optic chiasm and inner ear_L. The two AP approaches had similar MUs, which were significantly lower than the MUPs. The planning time of FAPs (145.00 ± 10.25 min) was slightly lower than that of CAPs (149.83 ± 14.37 min) and was substantially lower than that of MUPs (157.92 ± 16.11 min) with P < 0.0167. Overall, introducing the multi-isocenter AP technique into VMAT-CSI yielded positive outcomes and may play an important role in clinical CSI planning in the future.
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Affiliation(s)
- Yun Zhang
- Department of Radiation Oncology, Jiangxi Cancer Hospital, 519 East Beijing Road, Qingshanhu District, Nanchang 330029, China
| | - Yuling Huang
- Department of Radiation Oncology, Jiangxi Cancer Hospital, 519 East Beijing Road, Qingshanhu District, Nanchang 330029, China
| | - Jiafan Lin
- Department of Radiation Oncology, Jiangxi Cancer Hospital, 519 East Beijing Road, Qingshanhu District, Nanchang 330029, China
| | - Shenggou Ding
- Department of Radiation Oncology, Jiangxi Cancer Hospital, 519 East Beijing Road, Qingshanhu District, Nanchang 330029, China
| | - Xiaochang Gong
- Department of Radiation Oncology, Jiangxi Cancer Hospital, 519 East Beijing Road, Qingshanhu District, Nanchang 330029, China
| | - Qiegen Liu
- Department of Electronic Information Engineering, 999 Xuefu Dadao, Honggutan District, Nanchang 330031, China
| | - Changfei Gong
- Department of Radiation Oncology, Jiangxi Cancer Hospital, 519 East Beijing Road, Qingshanhu District, Nanchang 330029, China
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Hoeben BAW, Pazos M, Seravalli E, Bosman ME, Losert C, Albert MH, Boterberg T, Ospovat I, Mico Milla S, Demiroz Abakay C, Engellau J, Jóhannesson V, Kos G, Supiot S, Llagostera C, Bierings M, Scarzello G, Seiersen K, Smith E, Ocanto A, Ferrer C, Bentzen SM, Kobyzeva DA, Loginova AA, Janssens GO. ESTRO ACROP and SIOPE recommendations for myeloablative Total Body Irradiation in children. Radiother Oncol 2022; 173:119-133. [PMID: 35661674 DOI: 10.1016/j.radonc.2022.05.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 05/26/2022] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE Myeloablative Total Body Irradiation (TBI) is an important modality in conditioning for allogeneic hematopoietic stem cell transplantation (HSCT), especially in children with high-risk acute lymphoblastic leukemia (ALL). TBI practices are heterogeneous and institution-specific. Since TBI is associated with multiple late adverse effects, recommendations may help to standardize practices and improve the outcome versus toxicity ratio for children. MATERIAL AND METHODS The European Society for Paediatric Oncology (SIOPE) Radiotherapy TBI Working Group together with ESTRO experts conducted a literature search and evaluation regarding myeloablative TBI techniques and toxicities in children. Findings were discussed in bimonthly virtual meetings and consensus recommendations were established. RESULTS Myeloablative TBI in HSCT conditioning is mostly performed for high-risk ALL patients or patients with recurring hematologic malignancies. TBI is discouraged in children <3-4 years old because of increased toxicity risk. Publications regarding TBI are mostly retrospective studies with level III-IV evidence. Preferential TBI dose in children is 12-14.4 Gy in 1.6-2 Gy fractions b.i.d. Dose reduction should be considered for the lungs to <8 Gy, for the kidneys to ≤10 Gy, and for the lenses to <12 Gy, for dose rates ≥6 cGy/min. Highly conformal techniques i.e. TomoTherapy and VMAT TBI or Total Marrow (and/or Lymphoid) Irradiation as implemented in several centers, improve dose homogeneity and organ sparing, and should be evaluated in studies. CONCLUSIONS These ESTRO ACROP SIOPE recommendations provide expert consensus for conventional and highly conformal myeloablative TBI in children, as well as a supporting literature overview of TBI techniques and toxicities.
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Affiliation(s)
- Bianca A W Hoeben
- Dept. of Radiation Oncology, University Medical Center Utrecht, The Netherlands; Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
| | - Montserrat Pazos
- Dept. of Radiation Oncology, University Hospital, LMU Munich, Germany
| | - Enrica Seravalli
- Dept. of Radiation Oncology, University Medical Center Utrecht, The Netherlands
| | - Mirjam E Bosman
- Dept. of Radiation Oncology, University Medical Center Utrecht, The Netherlands
| | - Christoph Losert
- Dept. of Radiation Oncology, University Hospital, LMU Munich, Germany
| | - Michael H Albert
- Dept. of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU Munich, Germany
| | - Tom Boterberg
- Dept. of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Inna Ospovat
- Dept. of Radiation Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Soraya Mico Milla
- Dept. of Radiation Oncology, Vall d'Hebron University Hospital, Barcelona, Spain
| | - Candan Demiroz Abakay
- Dept. of Radiation Oncology, Uludag University Faculty of Medicine Hospital, Bursa, Turkey
| | - Jacob Engellau
- Dept. of Radiation Oncology, Skåne University Hospital, Lund, Sweden
| | | | - Gregor Kos
- Dept. of Radiation Oncology, Institute of Oncology Ljubljana, Slovenia
| | - Stéphane Supiot
- Dept. of Radiation Oncology, Institut de Cancérologie de l'Ouest, Nantes St. Herblain, France
| | - Camille Llagostera
- Dept. of Medical Physics, Institut de Cancérologie de l'Ouest, Nantes St. Herblain, France
| | - Marc Bierings
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Giovanni Scarzello
- Dept. of Radiation Oncology, Veneto Institute of Oncology-IRCCS, Padua, Italy
| | | | - Ed Smith
- Dept. of Radiation Oncology, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Abrahams Ocanto
- Dept. of Radiation Oncology, La Paz University Hospital, Madrid, Spain
| | - Carlos Ferrer
- Dept. of Medical Physics and Radiation Protection, La Paz University Hospital, Madrid, Spain
| | - Søren M Bentzen
- Dept. of Epidemiology and Public Health, Division of Biostatistics and Bioinformatics, University of Maryland School of Medicine, Baltimore, United States
| | - Daria A Kobyzeva
- Dept. of Radiation Oncology, Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Anna A Loginova
- Dept. of Radiation Oncology, Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Geert O Janssens
- Dept. of Radiation Oncology, University Medical Center Utrecht, The Netherlands; Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
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Nguyen M, Dang T, Deegan L, Henry K, Jones S, Pullar A, Cheuk R, Gibbs A, Sim L, Hargrave C. Modified volumetric modulated arc therapy technique with reduced planning and treatment time for craniospinal irradiation utilising two isocentres. J Med Radiat Sci 2022; 69:357-366. [PMID: 35460199 PMCID: PMC9442318 DOI: 10.1002/jmrs.582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/15/2022] [Accepted: 03/30/2022] [Indexed: 12/29/2022] Open
Abstract
Introduction Paediatric patients (individuals below 18 years of age) requiring cranial‐spinal irradiation (CSI) at our institution are commonly planned and treated using a three isocentre (3‐ISO) volumetric modulated arc therapy (VMAT) technique. A modified two isocentre (2‐ISO) VMAT technique was investigated with the aim to improve workflow and reduce planning and treatment time. Methods Five CSI paediatric patients previously treated with a 3‐ISO VMAT technique were retrospectively replanned using a 2‐ISO VMAT technique. The 2‐ISO VMAT plans were reviewed and approved by a radiation oncologist (RO) before undergoing patient‐specific quality assurance (QA) procedures, performed by a radiation oncology medical physicist (ROMP). Planning target volume (PTV) coverage, organ‐at‐risk (OAR) dose as well as planning and treatment durations of the first five patients utilising 2‐ISO technique were compared with 3‐ISO technique. Results The average percentage difference in PTV coverage by 95% reference dose between the 2‐ISO and 3‐ISO is 0.14%, and the average difference in OAR median dose is 0.68 Gy. Conformity and homogeneity indices have the same averages at 1.18 and 0.4 respectively. Patient‐specific physics QA results were all comparable with the 3‐ISO averages at 98.84% and the 2‐ISO at 98.71%. Planning duration for the 2‐ISO was reduced by up to 75%, and daily treatment duration was reduced by up to 50%. Of all the previously treated CSI patients using a 3‐ISO technique, 45% were suitable for the 2‐ISO technique. Conclusion The 2‐ISO VMAT technique provided comparable dose distribution based on PTV coverage, OAR dose and plan metric indices. Reduced planning and treatment duration with the 2‐ISO technique facilitated improved workflow with decreased sedation time for paediatric patients requiring a general anaesthesia.
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Affiliation(s)
- Minh Nguyen
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Thu Dang
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Liz Deegan
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Kelsie Henry
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Scott Jones
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Andrew Pullar
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Robyn Cheuk
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia.,Radiation Oncology and Radiation Therapy, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - Adrian Gibbs
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Lucy Sim
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia
| | - Catriona Hargrave
- Radiation Oncology Princess Alexandra Hospital Raymond Terrace, South Brisbane, Queensland, Australia.,Faculty of Health, School of Clinical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
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5
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Hoeben BAW, Wong JYC, Fog LS, Losert C, Filippi AR, Bentzen SM, Balduzzi A, Specht L. Total Body Irradiation in Haematopoietic Stem Cell Transplantation for Paediatric Acute Lymphoblastic Leukaemia: Review of the Literature and Future Directions. Front Pediatr 2021; 9:774348. [PMID: 34926349 PMCID: PMC8678472 DOI: 10.3389/fped.2021.774348] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 11/03/2021] [Indexed: 12/13/2022] Open
Abstract
Total body irradiation (TBI) has been a pivotal component of the conditioning regimen for allogeneic myeloablative haematopoietic stem cell transplantation (HSCT) in very-high-risk acute lymphoblastic leukaemia (ALL) for decades, especially in children and young adults. The myeloablative conditioning regimen has two aims: (1) to eradicate leukaemic cells, and (2) to prevent rejection of the graft through suppression of the recipient's immune system. Radiotherapy has the advantage of achieving an adequate dose effect in sanctuary sites and in areas with poor blood supply. However, radiotherapy is subject to radiobiological trade-offs between ALL cell destruction, immune and haematopoietic stem cell survival, and various adverse effects in normal tissue. To diminish toxicity, a shift from single-fraction to fractionated TBI has taken place. However, HSCT and TBI are still associated with multiple late sequelae, leaving room for improvement. This review discusses the past developments of TBI and considerations for dose, fractionation and dose-rate, as well as issues regarding TBI setup performance, limitations and possibilities for improvement. TBI is typically delivered using conventional irradiation techniques and centres have locally developed heterogeneous treatment methods and ways to achieve reduced doses in several organs. There are, however, limitations in options to shield organs at risk without compromising the anti-leukaemic and immunosuppressive effects of conventional TBI. Technological improvements in radiotherapy planning and delivery with highly conformal TBI or total marrow irradiation (TMI), and total marrow and lymphoid irradiation (TMLI) have opened the way to investigate the potential reduction of radiotherapy-related toxicities without jeopardising efficacy. The demonstration of the superiority of TBI compared with chemotherapy-only conditioning regimens for event-free and overall survival in the randomised For Omitting Radiation Under Majority age (FORUM) trial in children with high-risk ALL makes exploration of the optimal use of TBI delivery mandatory. Standardisation and comprehensive reporting of conventional TBI techniques as well as cooperation between radiotherapy centres may help to increase the ratio between treatment outcomes and toxicity, and future studies must determine potential added benefit of innovative conformal techniques to ultimately improve quality of life for paediatric ALL patients receiving TBI-conditioned HSCT.
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Affiliation(s)
- Bianca A. W. Hoeben
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, Netherlands
- Princess Máxima Center for Pediatric Oncology, Utrecht, Netherlands
| | - Jeffrey Y. C. Wong
- Department of Radiation Oncology, City of Hope National Medical Center and Beckman Research Institute, Duarte, CA, United States
| | - Lotte S. Fog
- Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, VIC, Australia
| | - Christoph Losert
- Department of Radiation Oncology, University Hospital, Ludwig Maximilian University of Munich, Munich, Germany
| | - Andrea R. Filippi
- Department of Radiation Oncology, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Søren M. Bentzen
- Division of Biostatistics and Bioinformatics, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Adriana Balduzzi
- Stem Cell Transplantation Unit, Clinica Paediatrica Università degli Studi di Milano Bicocca, Monza, Italy
| | - Lena Specht
- Department of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Zhou Y, Ai Y, Han C, Zheng X, Yi J, Xie C, Jin X. Impact of setup errors on multi-isocenter volumetric modulated arc therapy for craniospinal irradiation. J Appl Clin Med Phys 2020; 21:115-123. [PMID: 33070426 PMCID: PMC7700930 DOI: 10.1002/acm2.13044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 08/27/2020] [Accepted: 09/15/2020] [Indexed: 01/30/2023] Open
Abstract
Multi‐isocenter volumetric modulated arc therapy (VMAT) is recommended for craniospinal irradiation (CSI) to smooth the dose distribution in the junction regions relying solely on inverse optimization. However, few studies have measured the dosimetric impact of setup errors on this multi‐isocenter VMAT in the junction areas. The purpose of this study is to evaluate the impact of positional errors during VMAT CSI with two‐dimension (2D) and three‐dimension (3D) dosimetric measurements. A total of 20 patients treated by three‐isocenter VMAT CSI were retrospectively reviewed and analyzed. A 3D diode array ArcCHECK and radiochromic film EBT3 were applied to measure the percentage gamma passing rates (%GPs) and dose distributions in the junction areas between the cranial/upper‐spinal and the upper/lower‐spinal fields with intentionally introduced setup errors of ± 1 mm, ±2 mm, ±3 mm, ±5 mm, and ± 8 mm, respectively. The length and volume of planning target volume (PTV) for these CSI patients ranged from 50.14 to 80.8 cm, and 1572.3 to 2114.5 cm3, respectively. The %GPs for ±3 mm, ±5 mm, and ±8 mm positional errors were around 95%, 90%, and 85%, respectively, in the junction areas. The dosimetric verification results with EBT3 films indicated that cold and hot areas were observed with the increase of introduced setup errors. In conclusion, the dosimetric verification with intentionally introduced setup errors demonstrated that positional errors within 3 mm have a little impact for VMAT CSI, although setup errors should be minimized. Relying on the inverse optimization of VMAT to smooth the dose distribution in the junction areas is feasible for CSI.
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Affiliation(s)
- Yongqiang Zhou
- Department of radiation and medical oncology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yao Ai
- Department of radiation and medical oncology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Ce Han
- Department of radiation and medical oncology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaomin Zheng
- Department of radiation and medical oncology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jinling Yi
- Department of radiation and medical oncology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Congying Xie
- Department of radiation and medical oncology, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiance Jin
- Department of radiation and medical oncology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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7
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Automatic feathering algorithm for VMAT craniospinal irradiation: A comprehensive comparison with other VMAT planning strategies. Med Dosim 2020; 46:103-110. [PMID: 32967789 DOI: 10.1016/j.meddos.2020.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/22/2020] [Accepted: 09/11/2020] [Indexed: 01/06/2023]
Abstract
In craniospinal irradiation, field matching is very sensitive to intrafraction positional uncertainties in cranio-caudal direction, which could lead to severe overdoses/underdoses inside the planning target volume. During the last decade, significant efforts were made to develop volumetric-modulated arc therapy strategies, which were less sensitive to setup uncertainties. In this study, a treatment planning system-integrated method, named automatic feathering (AF) algorithm, was compared against other volumetric-modulated arc therapy strategies. Three patients were retrospectively included. Five different planning techniques were compared, including overlap (O), staggered overlap (SO), gradient optimization (GO), overlap with AF algorithm turned on (O-AF), and staggered overlap with AF algorithm turned on (SO-AF). Three overlapping lengths were considered (5 cm, 7.5 cm, and 10 cm). The middle isocenter was shifted of ±1 mm, ±3 mm, and ±5 mm to simulate setup uncertainties. Plan robustness against simulated uncertainties was evaluated by calculating near maximum and near minimum dose differences between shifted and nonshifted plans (ΔD2%, ΔD98%). Dose differences among combinations of techniques and junction lengths were tested using Wilcoxon signed-rank test. Higher ΔD2% and ΔD98% were obtained using the overlap technique (ΔD2% = 15.4%, ΔD98% = 15.0%). O-AF and SO-AF provided comparable plan robustness to GO technique. Their performance improved significantly for grater overlapping length. For 10-cm overlap and 5-mm shift, GO, O-AF, and SO-AF yielded to the better plan robustness (5.7% < ΔD2% < 6.0%, 6.1% < ΔD98% < 7.6%). SO provided an intermediate plan robustness (9.8% < ΔD2% < 10.8%, 8.9% < ΔD98% < 10.3%). The addition of AF to the overlap technique significantly improves plan robustness especially if larger overlapping lengths are used. Using the AF algorithm, plans become as robust as plans optimized with more sophisticated and time-consuming approaches (like GO).
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8
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Duan X, Zhou Y, Dai H, Zhao L, Qian J, Yang D, Zhang L, Luo C, Li G. Evaluating the positional uncertainty of intrafraction, adjacent fields, and daily setup with the BrainLAB ExacTrac system in patients who are receiving craniospinal irradiation. J Appl Clin Med Phys 2020; 21:35-46. [PMID: 32491280 PMCID: PMC7484826 DOI: 10.1002/acm2.12909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 03/27/2020] [Accepted: 04/21/2020] [Indexed: 11/21/2022] Open
Abstract
Purpose To investigate the daily setup, interfraction motion, variability in the junction areas, and dosimetric effect in craniospinal irradiation (CSI) patients. Methods Fifteen CSI patients who had undergone split‐field IMRT were followed in the study. Previous, middle, and posttreatment, each target volume position was evaluated using the ExacTrac system. Interfraction and intrafraction motions, the margin of the junction in adjacent targets volumes, and the dosimetric effect of the longitudinal residual error were analyzed. Results The lowest attainment rate within the tolerance of the initial setup error was 66.79% in six directions. The values of the initial error were within 15 mm (SD 4.5 mm) in the translation direction and 5° (SD 1.3°) in the rotation direction after the transposition of the treatment isocenter. With the guidance of the ExacTrac system, the interfraction and intrafraction residual errors were almost within the tolerance after correction, the margin of CTV‐to‐PCTV was in the range of target expansion criteria. The residual longitudinal errors resulted in only slight changes in the mean doses of PGTV and PCTV, while the maximum dose of the spinal cord increased by 16.1%. The patients did not exhibit any side‐effects by the overall treatment during the follow‐up period. Conclusions Position correction is necessary after setup and the transposition of the treatment isocenter. Intra‐fraction motion in the lateral direction should be monitored throughout treatment. The position errors in junction areas are almost within the tolerance after correction. The patients did not exhibit any side‐effects by the overall treatment.
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Affiliation(s)
- Xiaojuan Duan
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Yibing Zhou
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Hongya Dai
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Lirong Zhao
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Jindong Qian
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Dingqiang Yang
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Liwei Zhang
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Can Luo
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
| | - Guanghui Li
- Institute of Cancer ResearchXinqiao HospitalARMY Medical UniversityChongqingChina
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9
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Li W, Gillan C, Carpino-Rocca C, Keller H, Laperriere N, Coolens C. A Multidisciplinary Approach to Implement Image-Guided Craniospinal Irradiation. J Med Imaging Radiat Sci 2020; 51:317-323. [PMID: 32245671 DOI: 10.1016/j.jmir.2020.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/14/2020] [Accepted: 02/19/2020] [Indexed: 11/17/2022]
Abstract
PURPOSE Practical considerations dictated a change in the craniospinal irradiation (CSI) technique. We report our experience in developing and refining CSI planning and treatment parameters, using a 3-isocenter image-guided intensity-modulated radiation therapy (IG-IMRT) technique. METHODS AND MATERIALS Two institutional values guided development: multidisciplinary decision-making and coordinated considerations throughout simulation, planning, and delivery. Patient immobilization and simulation parameters were selected based on treatment delivery system limitations. Commissioning fluence verification maps were acquired to verify dose in regions of overlapping fields. Robustness analysis was performed to assess impact of potential setup errors measured through IGRT verification. Treatment considerations included order of isocenter imaging and treatment and respective IGRT frequency, modality, and image registration thresholds. RESULTS Overall film measurements were within 3% of planned dose, confirmed by phantom composite measurements showing all points were within 97% of planned dose. Setup sensitivity analysis suggested a 3-mm setup tolerance was sufficient to ensure confidence in the delivered plan. As the most critical organs at risk were in the superior isocenter, the daily isocenter treatment order was confirmed as superior, middle, and inferior. Daily cone beam computed tomography guidance was chosen for all isocenters (3° rotational threshold). Except for the superior/inferior direction of the middle and inferior isocenters, which were adjusted to 3 mm based on sensitivity analysis, a 1-mm translational threshold was used. CONCLUSIONS An IG-IMRT CSI technique has been developed and implemented in our institution through a multidisciplinary approach. This process highlights the collaborative, iterative approach used to successfully integrate a new treatment technique in an image-guidance era.
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Affiliation(s)
- Winnie Li
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.
| | - Caitlin Gillan
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Cathy Carpino-Rocca
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Harald Keller
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Normand Laperriere
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Catherine Coolens
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
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10
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Rafic KHM, Sujith C, Rajesh B, Babu S ES, Timothy PB, Selvamani B, Ravindran PB. A new strategy for craniospinal axis localization and adaptive dosimetric evaluation using cone beam CT. Rep Pract Oncol Radiother 2020; 25:282-292. [PMID: 32140087 PMCID: PMC7052077 DOI: 10.1016/j.rpor.2019.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/02/2019] [Accepted: 11/29/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND AIM Computational complexities encountered in craniospinal irradiation (CSI) have been widely investigated with different planning strategies. However, localization of the entire craniospinal axis (CSA) and evaluation of adaptive treatment plans have traditionally been ignored in CSI treatment. In this study, a new strategy for CSI with comprehensive CSA localization and adaptive plan evaluation has been demonstrated using cone beam CT with extended longitudinal field-of-view (CBCTeLFOV). MATERIALS AND METHODS Multi-scan CBCT images were acquired with fixed longitudinal table translations (with 1 cm cone-beam overlap) and then fused into a single DICOM-set using the custom software coded in MatLab™. A novel approach for validation of CBCTeLFOV was demonstrated by combined geometry of Catphan-504 and Catphan-604 phantoms. To simulate actual treatment scenarios, at first, the end-to-end workflow of CSI with VMAT was investigated using an anthropomorphic phantom and then applied for two patients (based on random selection). RESULTS The fused CBCTeLFOV images were in excellent agreement with planning CT (pCT). The custom developed software effectively manages spatial misalignments arising out of the uncertainties in treatment/setup geometry. Although the structures mapped from pCT to CBCTeLFOV showed minimal variations, a maximum spatial displacement of up to 1.2 cm (and the mean of 0.8 ± 0.3 cm) was recorded in phantom study. Adaptive plan evaluation of patient paradigms showed the likelihood of under-dosing the craniospinal target. CONCLUSION Our protocol serves as a guide for precise localization of entire CSA and to ensure adequate dose to the large and complex targets. It can also be adapted for other complex treatment techniques such as total-marrow-irradiation and total-lymphoid-irradiation.
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Affiliation(s)
| | | | | | | | - Peace Balasingh Timothy
- Department of Radiation Oncology, Christian Medical College, Vellore 632 004, Tamil Nadu, India
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11
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Hong CS, Kim MJ, Kim J, Chang KH, Park K, Kim DW, Han MC, Yoon HI, Kim JS, Lee H. Feasibility of hybrid TomoHelical- and TomoDirect-based volumetric gradient matching technique for total body irradiation. Radiat Oncol 2019; 14:233. [PMID: 31856870 PMCID: PMC6924057 DOI: 10.1186/s13014-019-1435-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/02/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tomotherapy-based total body irradiation (TBI) is performed using the head-first position (HFP) and feet-first position (FFP) due to treatment length exceeding the 135 cm limit. To reduce the dosimetric variation at the match lines, we propose and verify a volumetric gradient matching technique (VGMT) by combining TomoHelical (TH) and TomoDirect (TD) modes. METHODS Two planning CT image sets were acquired with HFP and FFP using 15 × 55 × 18 cm3 of solid water phantom. Planning target volume (PTV) was divided into upper, lower, and gradient volumes. The junction comprised 2-cm thick five and seven gradient volumes (5-GVs and 7-GVs) to create a dose distribution with a gentle slope. TH-IMRT and TD-IMRT plans were generated with 5-GVs and 7-GVs. The setup error in the calculated dose was assessed by shifting dose distribution of the FFP plan by 5, 10, 15, and 20 mm in the longitudinal direction and comparing it with the original. Doses for 95% (D95) and 5% of the PTV (D5) were calculated for all simulated setup error plans. Absolute dose measurements were performed using an ionization chamber in the junction. RESULTS The TH&TD plan produced a linear gradient in junction volume, comparable to that of the TH&TH plan. D5 of the PTV was 110% of the prescribed dose when the FFP plan was shifted 0.7 cm and 1.2 cm in the superior direction for 5-GVs and 7-GVs. D95 of the PTV decreased to < 90% of the prescribed dose when the FF plan was shifted 1.1 cm and 1.3 cm in the inferior direction for 5-GVs and 7-GVs. The absolute measured dose showed a good correlation with the calculated dose in the gradient junction volume. The average percent difference (±SD) in all measured points was - 0.7 ± 1.6%, and the average dose variations between depths was - 0.18 ± 1.07%. CONCLUSION VGMT can create a linear dose gradient across the junction area in both TH&TH and TH&TD and can minimize the dose sensitivity to longitudinal setup errors in tomotherapy-based TBI.
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Affiliation(s)
- Chae-Seon Hong
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Min-Joo Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Jihun Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Kyung Hwan Chang
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Kwangwoo Park
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Dong Wook Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Min Cheol Han
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Hong In Yoon
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Jin Sung Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea.
| | - Ho Lee
- Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul, 06273, South Korea.
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12
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Sarkar B, Munshi A, Ganesh T, Manikandan A, Mohanti BK. Dosimetric comparison of short and full arc in spinal PTV in volumetric-modulated arc therapy-based craniospinal irradiation. Med Dosim 2019; 45:1-6. [PMID: 30995966 DOI: 10.1016/j.meddos.2019.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 03/08/2019] [Accepted: 03/22/2019] [Indexed: 12/01/2022]
Abstract
Since 2011 when it was first described, the volumetric-modulated arc therapy (VMAT) technique for craniospinal irradiation (CSI) has always seen the use of large arc lengths for the spine fields ranging from 200° to 360°. This study was aimed to do a dosimetric comparison between the large and shorter spinal arc for CSI. For a cohort of 10 patients, 2 VMAT CSI plans were created for each patient, one using the conventional full 360° arc (VMAT_FA) for the spine and the other using 100° posterior arc (VMAT_PA) for 23.4 Gy and 35 Gy prescriptions. In both the plans, 360° arc fields were employed for treating cranial volume. Spillage dose (DBody-PTV) to Body-PTV (DBody-PTV: dose to body excluding planning target volume) was compared with VMAT_FA and VMAT_PA plans. In addition to these VMAT plans, a 3-dimensional conformal radiotherapy plan was also created for all these patients to compare the DBody-PTV and target volume related dose constraints. Mean D95% difference between the two VMAT plans did not exceed 1.3% for cranial and spinal targets for both prescription levels. The conformity index (CI) was averaged over both prescription doses. Average CI shows a similar value for VMAT_FA (0.84 ± 0.04) and VMAT_PA (0.82 ± 0.05) plans. D95%, V110% and CI did not exhibit a statistically significant difference between partial and full-arc VMAT plans. However, the VMAT_PA plan exhibited a lower DBody-PTV compared to VMAT_FA plans (0.007 ≤ p < 0.05) in the 1 to 5 Gy range. Nevertheless, partial arc plans could not offer a statistically significant dose reduction for delineated organs compared to full arc plans, except for bilateral kidneys.
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Affiliation(s)
- Biplab Sarkar
- Radiation Oncology, Manipal Hospitals, New Delhi, Delhi 110075, India.
| | - Anusheel Munshi
- Radiation Oncology, Manipal Hospitals, New Delhi, Delhi 110075, India
| | | | - Arjunan Manikandan
- Radiation Oncology, Nagarjuna Hospitals, Vijayawada, Andhra Pradesh 520007, India
| | - Bidhu K Mohanti
- Radiation Oncology, Manipal Hospitals, New Delhi, Delhi 110075, India
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13
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Feasibility of a novel dose fractionation strategy in TMI/TMLI. Radiat Oncol 2018; 13:248. [PMID: 30558631 PMCID: PMC6296054 DOI: 10.1186/s13014-018-1201-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 12/09/2018] [Indexed: 11/17/2022] Open
Abstract
Background To report our experience in planning and delivering total marrow irradiation (TMI) and total marrow and lymphatic irradiation (TMLI) in patients with hematologic malignancies. Methods Twenty-seven patients undergoing bone marrow transplantation were treated with TMI/TMLI using Helical Tomotherapy (HT). All skeletal bones exclusion of the mandible comprised the treatment target volume and, for TMLI, lymph node chains, liver, spleen and/or brain were also included according to the clinical indication. Planned dose of 8Gy in 2 fractions was delivered over 1 day for TMI while 10Gy in 2 fractions BID was used for TMLI. Organs at risk (OAR) contoured included the brain, brainstem, lens, eyes, optic nerves, parotids, oral cavity, lungs, heart, liver, kidneys, stomach, small bowel, bladder and rectum. In particular, a simple method to avoid hot or cold doses in the overlapping region was implemented and the plan sum was adopted to evaluate dose inhomogeneity. Furthermore, setup errors from 54 treatments were summarized to gauge the effectiveness of immobilization. Results During the TMI/TMLI treatment, no acute adverse effects occurred during the radiation treatment. Two patients suffered nausea or vomiting right after radiation course. For the 9 patients treated with TMI, the median dose reduction of major organs varied 30–65% of the prescribed dose, substantially lower than the traditional total body irradiation (TBI). Meanwhile, average biological equivalent doses to OARs with 8Gy/2F TMI approach were not different from the conventional 12Gy/6F TMI approach. In the dose junction region, the 93% of PTV was covered by the prescribed dose without obvious hotspots. For the 27 patients, the overall setup corrections were lower than 3 mm except those in the SI direction for abdomen-pelvis region, demonstrating excellent immobilization. Conclusion The present study confirmed the technical feasibility of HT-based TMI/TMLI delivering 8-10Gy in 2 fractions over 1 day. For patients undergoing hematopoietic cell transplantation the proposed 8Gy/2F TMI (or 10Gy/2F TMLI) strategy may be a novel approach to improve delivery efficiency, increase effective radiation dose to target while maintaining low risk of severe organ toxicities.
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14
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McVicar N. Improved Volumetric Modulated Arc Therapy Field Junctions Using In Silico Base Plans: Application to Craniospinal Irradiation. J Med Imaging Radiat Sci 2018; 49:301-308. [PMID: 32074057 DOI: 10.1016/j.jmir.2018.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 05/09/2018] [Accepted: 05/09/2018] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Field junctions present a major challenge for planning craniospinal irradiation (CSI) using volumetric modulated arc therapy (VMAT). In this study, the feasibility of using in silico base dose distributions for planning junctioned VMAT fields for CSI is assessed. METHODS An in-house computer program was created to generate strategic base plans with controlled linear dose gradients across the junction. The algorithm was generalized to allow user-defined parameters such as number of junctions and junction length. In silico base plans were used to optimize junctioned VMAT CSI plans for a pediatric case and an adult case. Throughout optimization, dose to the eyes, kidneys, lungs, heart, and liver were minimized. Final plan quality was evaluated using the percent of planning target volume receiving at least 95% prescription dose (V95%), homogeneity index, and conformity number. Final plan robustness to setup error was evaluated using changes in near-minimum, median, and near-maximum doses defined as the most exposed 98%, 50%, and 2% of the planning target volume (D98%, D50%, D2%) within the junction region before and after setup errors of ±3, ±5, and ±7 mm in the craniocaudal direction. RESULTS The program generated ideal in silico dose distributions that were compatible with a commercial treatment planning system for use as base doses during VMAT optimization. VMAT plans, that were optimized with the in silico base plans, had complementary linear dose profiles across the junction. Final pediatric and adult VMAT CSI plans both had V95% ≥98.1% and 98.1%, homogeneity index: 0.09 and 0.10, and conformity number: 0.86, 0.84, respectively. In addition, dose to surrounding organs at risk was acceptably low for both cases. For ±3 mm setup errors, small variations in the junction dose were recorded with ΔD98% ≤2.3%, ΔD50% ≤2.3%, and ΔD2% ≤2.8%. CONCLUSIONS This is the first demonstration of junctioned VMAT field optimization with a controlled linear dose gradient across the junction without the use of any extra planning contours. Planning junctioned VMAT using in silico base plans is feasible and capable of generating high-quality plans that are robust to clinically expected setup variations.
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Affiliation(s)
- Nevin McVicar
- BC Cancer Agency - Vancouver Cancer Centre, Department of Medical Physics, Vancouver, British Columbia, Canada.
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15
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Wong KK, Ragab O, Tran HN, Pham A, All S, Waxer J, Olch AJ. Acute toxicity of craniospinal irradiation with volumetric-modulated arc therapy in children with solid tumors. Pediatr Blood Cancer 2018; 65:e27050. [PMID: 29630782 DOI: 10.1002/pbc.27050] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/30/2018] [Accepted: 02/14/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Craniospinal irradiation (CSI) is an important part of curative radiation therapy (RT) for many types of pediatric brain or solid tumors. After conventional CSI, long term survivors may experience sequelae due to unintended dose to normal tissue. Volumetric modulated arc therapy (VMAT) CSI reduces off-target doses at the cost of greater complexity and error risk, and we describe our initial experience in a group of pediatric patients with solid tumors presenting with disseminated or recurrent disease. PROCEDURE Pediatric patients with brain tumors were identified at Children's Hospital Los Angeles from 2013 to 2015. Clinical characteristics, acute toxicity, and radiotherapy data were abstracted from their medical records. We identified 19 patients who received VMAT CSI. Quality assurance was performed with a cylindrical detector array and ion chamber measurements at the arc junctions. RESULTS Patients had medulloblastoma or supratentorial primitive neuro-ectodermal tumor (n = 14, 11 high risk), germ cell tumors (two), relapsed neuroblastoma (two), and atypical teratoid/rhabdoid tumor (one). The most common acute toxicity was hematologic, including leukopenia (11% grade [Gr] 2, 26% Gr 3, and 63% Gr 4), anemia (89% Gr 2), and thrombocytopenia (16% Gr 1-2, 26% Gr 3, and 37% Gr 4). Despite leukopenia, we encountered only two Gr 3 infections (urinary tract and lung). The majority required blood products (89% red blood cells and 68% platelets). Weight loss was also common (47% Gr 1 and 26% Gr 2). CONCLUSIONS VMAT CSI, along with chemotherapy and anesthesia, is feasible with supportive care. Daily image-guided RT improves accuracy and reduces the risk of spinal cord overdose without increasing treatment time. Further research is needed to determine whether reducing doses to organs, such as thyroid, heart, or hippocampus, offsets the risk of increased volume of low-dose irradiation.
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Affiliation(s)
- Kenneth K Wong
- Department of Radiation Oncology, Keck School of Medicine of the University of Southern California, Los Angeles, California.,Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California
| | - Omar Ragab
- Department of Radiation Oncology, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - Hung N Tran
- Pediatric Neuro-Oncology, Department of Pediatrics, Kaiser Permanente, Los Angeles, California
| | - Anthony Pham
- Department of Radiation Oncology, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - Sean All
- College of Medicine, University of Central Florida, Orlando, Florida
| | - Jonathan Waxer
- School of Medicine, Tulane University, New Orleans, Louisiana
| | - Arthur J Olch
- Department of Radiation Oncology, Keck School of Medicine of the University of Southern California, Los Angeles, California.,Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California
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Wang K, Meng H, Chen J, Zhang W, Feng Y. Plan quality and robustness in field junction region for craniospinal irradiation with VMAT. Phys Med 2018; 48:21-26. [DOI: 10.1016/j.ejmp.2018.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 03/02/2018] [Accepted: 03/11/2018] [Indexed: 02/05/2023] Open
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