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Gambetta V, Fredriksson A, Menkel S, Richter C, Stützer K. The partial adaptation strategy for online-adaptive proton therapy: A proof of concept study in head and neck cancer patients. Med Phys 2024; 51:5572-5581. [PMID: 38837396 DOI: 10.1002/mp.17178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/06/2024] [Accepted: 04/08/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND The accuracy of intensity-modulated proton therapy (IMPT) is greatly affected by anatomy variations that might occur during the treatment course. Online plan adaptations have been proposed as a solution to intervene promptly during a treatment session once the anatomy changes are detected. The implementation of online-adaptive proton therapy (OAPT) is still hindered by time-consuming tasks in the workflow. PURPOSE The study introduces the novel concept of partial adaptation and aims at investigating its feasibility as a potential solution to parallelize tasks during an OAPT workflow for saving valuable in-room time. METHODS The proof-of-principle simulation study includes datasets from six head and neck cancer (HNC) patients, each consisting of one planning CT (pCT) and three contoured control CTs (cCTs). Robust 3-field normo-fractionated initial IMPT plans were generated on the pCTs with a standardized field configuration, delivering 66 Gy and 54 Gy to the high-risk and low-risk clinical target volume (CTVHigh and CTVLow), respectively. For each cCT, a dose-mimicking-based partial adaptation was applied: two fields were adapted on the current anatomy taking into account the background dose of the first non-adapted field supposedly delivered in the meantime. Fraction doses on the cCTs resulting from partially adapted plans with different first (non-adapted) field assignments were compared against those from non-adapted and fully adapted plans regarding target coverage and organs at risk (OARs) sparing. The robustness of partially adapted plans was also evaluated. RESULTS Partially adapted plans showed comparable results to fully adapted plans and were superior to non-adapted plans for both target coverage and OAR sparing. Target coverage degradation in the non-adapted plans (median D98%: 95.9% and 97.5% for CTVLow and CTVHigh, respectively) was recovered by both partial (98.0% and 98.5%) and full adaptation (98.2% and 98.7%) in comparison to the initial plans (98.7% and 98.8%). The initial hotspot dose for the CTVHigh (median D2%: 101.8%) increased in the non-adapted plans (102.9%) and was recovered by the adaptive strategies (partial: 102.5%, full: 101.9%). The near-maximum dose (D0.01cc) to brainstem and spinal cord was within clinical constraints for all investigated dose distributions, but clearly increased for no adaptation and improved in the (both partially and fully) adapted plans with respect to the non-adapted ones. The parotids' median doses (D50) were mainly patient-specific depending on the proximity to the target region, but anyway lower for the partially and fully adapted plans compared to the non-adapted ones. OAR sparing was furthermore improved for the partially adapted plans in comparison to full adaptation. Robustness of the target dose metrics was preserved in all evaluated scenarios. CONCLUSIONS For OAPT of HNC patients, partial adaptation is able to generate plans of superior conformity to non-adapted plans and of comparable conformity as fully adapted plans, while having the potential to speed up the online-adaptive workflows. Thus, partial adaptation represents an intermediate approach until fast online adaptation workflows become available. Furthermore, it can be applied in workflows where online treatment verification stops the delivery and triggers an online adaptation for the remaining fraction.
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Affiliation(s)
- Virginia Gambetta
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | | | - Stefan Menkel
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kristin Stützer
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
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Lee D, Renz P, Oh S, Hwang MS, Pavord D, Yun KL, Collura C, McCauley M, Colonias A(T, Trombetta M, Kirichenko A. Online Adaptive MRI-Guided Stereotactic Body Radiotherapy for Pancreatic and Other Intra-Abdominal Cancers. Cancers (Basel) 2023; 15:5272. [PMID: 37958447 PMCID: PMC10648954 DOI: 10.3390/cancers15215272] [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: 09/29/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
A 1.5T MRI combined with a linear accelerator (Unity®, Elekta; Stockholm, Sweden) is a device that shows promise in MRI-guided stereotactic body radiation treatment (SBRT). Previous studies utilized the manufacturer's pre-set MRI sequences (i.e., T2 Weighted (T2W)), which limited the visualization of pancreatic and intra-abdominal tumors and organs at risk (OAR). Here, a T1 Weighted (T1W) sequence was utilized to improve the visualization of tumors and OAR for online adapted-to-position (ATP) and adapted-to-shape (ATS) during MRI-guided SBRT. Twenty-six patients, 19 with pancreatic and 7 with intra-abdominal cancers, underwent CT and MRI simulations for SBRT planning before being treated with multi-fractionated MRI-guided SBRT. The boundary of tumors and OAR was more clearly seen on T1W image sets, resulting in fast and accurate contouring during online ATP/ATS planning. Plan quality in 26 patients was dependent on OAR proximity to the target tumor and achieved 96 ± 5% and 92 ± 9% in gross tumor volume D90% and planning target volume D90%. We utilized T1W imaging (about 120 s) to shorten imaging time by 67% compared to T2W imaging (about 360 s) and improve tumor visualization, minimizing target/OAR delineation uncertainty and the treatment margin for sparing OAR. The average time-consumption of MRI-guided SBRT for the first 21 patients was 55 ± 15 min for ATP and 79 ± 20 min for ATS.
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Affiliation(s)
- Danny Lee
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
- College of Medicine, Radiologic Sciences/Drexel University, Philadelphia, PA 19129, USA
| | - Paul Renz
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
| | - Seungjong Oh
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
- College of Medicine, Radiologic Sciences/Drexel University, Philadelphia, PA 19129, USA
| | - Min-Sig Hwang
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
- College of Medicine, Radiologic Sciences/Drexel University, Philadelphia, PA 19129, USA
| | - Daniel Pavord
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
- College of Medicine, Radiologic Sciences/Drexel University, Philadelphia, PA 19129, USA
| | - Kyung Lim Yun
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
| | - Colleen Collura
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
| | - Mary McCauley
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
| | - Athanasios (Tom) Colonias
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
| | - Mark Trombetta
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
- College of Medicine, Radiologic Sciences/Drexel University, Philadelphia, PA 19129, USA
| | - Alexander Kirichenko
- Radiation Oncology, Allegheny Health Network, Pittsburgh, PA 15012, USA; (P.R.); (S.O.); (M.-S.H.); (D.P.); (K.L.Y.); (C.C.); (M.M.); (M.T.); (A.K.)
- College of Medicine, Radiologic Sciences/Drexel University, Philadelphia, PA 19129, USA
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Ates O, Uh J, Pirlepesov F, Hua CH, Merchant TE, Krasin MJ. Monitoring of Interfractional Proton Range Verification and Dosimetric Impact Based on Daily CBCT for Pediatric Patients with Pelvic Tumors. Cancers (Basel) 2023; 15:4200. [PMID: 37686476 PMCID: PMC10486424 DOI: 10.3390/cancers15174200] [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: 07/17/2023] [Revised: 08/18/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023] Open
Abstract
(1) Background: Synthetic CT images of the pelvis were generated from daily CBCT images to monitor changes in water equivalent path length (WEPL) and determine the dosimetric impact of anatomy changes along the proton beam's path; (2) Methods: Ten pediatric patients with pelvic tumors treated using proton therapy with daily CBCT were included. The original planning CT was deformed to the same-day CBCT to generate synthetic CT images for WEPL comparison and dosimetric evaluation; (3) Results: WEPL changes of 20 proton fields at the distal edge of the CTV ranged from 0.1 to 12 mm with a median of 2.5 mm, and 75th percentile of 5.1 mm for (the original CT-rescanned CT) and ranged from 0.3 to 10.1 mm with a median of 2.45 mm and 75th percentile of 4.8 mm for (the original CT-synthetic CT). The dosimetric impact was due to proton range pullback or overshoot, which led to reduced coverage in CTV Dmin averaging 12.1% and 11.3% in the rescanned and synthetic CT verification plans, respectively; (4) Conclusions: The study demonstrated that synthetic CT generated by deforming the original planning CT to daily CBCT can be used to quantify proton range changes and predict adverse dosimetric scenarios without the need for excessive rescanned CT scans during large interfractional variations in adaptive proton therapy of pediatric pelvic tumors.
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Affiliation(s)
- Ozgur Ates
- St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (J.U.); (F.P.); (C.-H.H.); (T.E.M.); (M.J.K.)
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Taylor S, Lim P, Cantwell J, D’Souza D, Moinuddin S, Chang YC, Gaze MN, Gains J, Veiga C. Image guidance and interfractional anatomical variation in paediatric abdominal radiotherapy. Br J Radiol 2023; 96:20230058. [PMID: 37102707 PMCID: PMC10230397 DOI: 10.1259/bjr.20230058] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 04/28/2023] Open
Abstract
OBJECTIVES To identify variables predicting interfractional anatomical variations measured with cone-beam CT (CBCT) throughout abdominal paediatric radiotherapy, and to assess the potential of surface-guided radiotherapy (SGRT) to monitor these changes. METHODS Metrics of variation in gastrointestinal (GI) gas volume and separation of the body contour and abdominal wall were calculated from 21 planning CTs and 77 weekly CBCTs for 21 abdominal neuroblastoma patients (median 4 years, range: 2 - 19 years). Age, sex, feeding tubes, and general anaesthesia (GA) were explored as predictive variables for anatomical variation. Furthermore, GI gas variation was correlated with changes in body and abdominal wall separation, as well as simulated SGRT metrics of translational and rotational corrections between CT/CBCT. RESULTS GI gas volumes varied 74 ± 54 ml across all scans, while body and abdominal wall separation varied 2.0 ± 0.7 mm and 4.1 ± 1.5 mm from planning, respectively. Patients < 3.5 years (p = 0.04) and treated under GA (p < 0.01) experienced greater GI gas variation; GA was the strongest predictor in multivariate analysis (p < 0.01). Absence of feeding tubes was linked to greater body contour variation (p = 0.03). GI gas variation correlated with body (R = 0.53) and abdominal wall (R = 0.63) changes. The strongest correlations with SGRT metrics were found for anterior-posterior translation (R = 0.65) and rotation of the left-right axis (R = -0.36). CONCLUSIONS Young age, GA, and absence of feeding tubes were linked to stronger interfractional anatomical variation and are likely indicative of patients benefiting from adaptive/robust planning pathways. Our data suggest a role for SGRT to inform the need for CBCT at each treatment fraction in this patient group. ADVANCES IN KNOWLEDGE This is the first study to suggest the potential role of SGRT for the management of internal interfractional anatomical variation in paediatric abdominal radiotherapy.
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Affiliation(s)
- Sabrina Taylor
- University College London, Centre for Medical Image Computing, London, United Kingdom
| | - Pei Lim
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Jessica Cantwell
- Radiotherapy, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Derek D’Souza
- Radiotherapy, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Syed Moinuddin
- Radiotherapy, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Yen-Ching Chang
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Mark N Gaze
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Jennifer Gains
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Catarina Veiga
- University College London, Centre for Medical Image Computing, London, United Kingdom
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5
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Qiu Z, Olberg S, den Hertog D, Ajdari A, Bortfeld T, Pursley J. Online adaptive planning methods for intensity-modulated radiotherapy. Phys Med Biol 2023; 68:10.1088/1361-6560/accdb2. [PMID: 37068488 PMCID: PMC10637515 DOI: 10.1088/1361-6560/accdb2] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 04/17/2023] [Indexed: 04/19/2023]
Abstract
Online adaptive radiation therapy aims at adapting a patient's treatment plan to their current anatomy to account for inter-fraction variations before daily treatment delivery. As this process needs to be accomplished while the patient is immobilized on the treatment couch, it requires time-efficient adaptive planning methods to generate a quality daily treatment plan rapidly. The conventional planning methods do not meet the time requirement of online adaptive radiation therapy because they often involve excessive human intervention, significantly prolonging the planning phase. This article reviews the planning strategies employed by current commercial online adaptive radiation therapy systems, research on online adaptive planning, and artificial intelligence's potential application to online adaptive planning.
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Affiliation(s)
- Zihang Qiu
- Department of Business Analytics, University of Amsterdam, The Netherlands
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, United States of America
| | - Sven Olberg
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, United States of America
| | - Dick den Hertog
- Department of Business Analytics, University of Amsterdam, The Netherlands
| | - Ali Ajdari
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, United States of America
| | - Thomas Bortfeld
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, United States of America
| | - Jennifer Pursley
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, United States of America
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Szmul A, Taylor S, Lim P, Cantwell J, Moreira I, Zhang Y, D’Souza D, Moinuddin S, Gaze MN, Gains J, Veiga C. Deep learning based synthetic CT from cone beam CT generation for abdominal paediatric radiotherapy. Phys Med Biol 2023; 68:105006. [PMID: 36996837 PMCID: PMC10160738 DOI: 10.1088/1361-6560/acc921] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 03/13/2023] [Accepted: 03/30/2023] [Indexed: 04/01/2023]
Abstract
Objective. Adaptive radiotherapy workflows require images with the quality of computed tomography (CT) for re-calculation and re-optimisation of radiation doses. In this work we aim to improve the quality of on-board cone beam CT (CBCT) images for dose calculation using deep learning.Approach. We propose a novel framework for CBCT-to-CT synthesis using cycle-consistent Generative Adversarial Networks (cycleGANs). The framework was tailored for paediatric abdominal patients, a challenging application due to the inter-fractional variability in bowel filling and small patient numbers. We introduced to the networks the concept of global residuals only learning and modified the cycleGAN loss function to explicitly promote structural consistency between source and synthetic images. Finally, to compensate for the anatomical variability and address the difficulties in collecting large datasets in the paediatric population, we applied a smart 2D slice selection based on the common field-of-view (abdomen) to our imaging dataset. This acted as a weakly paired data approach that allowed us to take advantage of scans from patients treated for a variety of malignancies (thoracic-abdominal-pelvic) for training purposes. We first optimised the proposed framework and benchmarked its performance on a development dataset. Later, a comprehensive quantitative evaluation was performed on an unseen dataset, which included calculating global image similarity metrics, segmentation-based measures and proton therapy-specific metrics.Main results. We found improved performance for our proposed method, compared to a baseline cycleGAN implementation, on image-similarity metrics such as Mean Absolute Error calculated for a matched virtual CT (55.0 ± 16.6 HU proposed versus 58.9 ± 16.8 HU baseline). There was also a higher level of structural agreement for gastrointestinal gas between source and synthetic images measured using the dice similarity coefficient (0.872 ± 0.053 proposed versus 0.846 ± 0.052 baseline). Differences found in water-equivalent thickness metrics were also smaller for our method (3.3 ± 2.4% proposed versus 3.7 ± 2.8% baseline).Significance. Our findings indicate that our innovations to the cycleGAN framework improved the quality and structure consistency of the synthetic CTs generated.
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Affiliation(s)
- Adam Szmul
- Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, United Kingdom
| | - Sabrina Taylor
- Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Pei Lim
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Jessica Cantwell
- Radiotherapy, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Isabel Moreira
- Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Ying Zhang
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Derek D’Souza
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Syed Moinuddin
- Radiotherapy, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Mark N. Gaze
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Jennifer Gains
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Catarina Veiga
- Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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Paganetti H, Botas P, Sharp GC, Winey B. Adaptive proton therapy. Phys Med Biol 2021; 66:10.1088/1361-6560/ac344f. [PMID: 34710858 PMCID: PMC8628198 DOI: 10.1088/1361-6560/ac344f] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/28/2021] [Indexed: 12/25/2022]
Abstract
Radiation therapy treatments are typically planned based on a single image set, assuming that the patient's anatomy and its position relative to the delivery system remains constant during the course of treatment. Similarly, the prescription dose assumes constant biological dose-response over the treatment course. However, variations can and do occur on multiple time scales. For treatment sites with significant intra-fractional motion, geometric changes happen over seconds or minutes, while biological considerations change over days or weeks. At an intermediate timescale, geometric changes occur between daily treatment fractions. Adaptive radiation therapy is applied to consider changes in patient anatomy during the course of fractionated treatment delivery. While traditionally adaptation has been done off-line with replanning based on new CT images, online treatment adaptation based on on-board imaging has gained momentum in recent years due to advanced imaging techniques combined with treatment delivery systems. Adaptation is particularly important in proton therapy where small changes in patient anatomy can lead to significant dose perturbations due to the dose conformality and finite range of proton beams. This review summarizes the current state-of-the-art of on-line adaptive proton therapy and identifies areas requiring further research.
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Affiliation(s)
- Harald Paganetti
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pablo Botas
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- Foundation 29 of February, Pozuelo de Alarcón, Madrid, Spain
| | - Gregory C Sharp
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brian Winey
- Department of Radiation Oncology, Physics Division, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
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Narita Y, Kato T, Takemasa K, Sato H, Ikeda T, Harada T, Oyama S, Murakami M. Dosimetric impact of simulated changes in large bowel content during proton therapy with simultaneous integrated boost for locally advanced pancreatic cancer. J Appl Clin Med Phys 2021; 22:90-98. [PMID: 34599856 PMCID: PMC8598140 DOI: 10.1002/acm2.13429] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 07/31/2021] [Accepted: 09/07/2021] [Indexed: 12/11/2022] Open
Abstract
Purpose To investigate the dosimetric impact of changes in the large bowel content during proton therapy (PT) with simultaneous integrated boost (SIB) for locally advanced pancreatic cancer (LAPC). Materials and methods Fifteen patients with LAPC were included in this study. The SIB method was performed using five fields according to our standard protocol. A total dose of 67.5 Gy(relative biological effectiveness [RBE]) was prescribed in 25 fractions using the SIB method. A dose of 45 Gy(RBE) was prescribed for the entire planning target volume (PTV) by using four main fields. The remaining 22.5 Gy(RBE) was prescribed to the PTV excluding for the gastrointestinal tract using one subfield. Five simulated doses were obtained by the forward dose calculations with the Hounsfield units (HU) override to the large bowel to 50, 0, −100, −500, and −1000, respectively. The dose‐volume indices in each plan were compared using the 50 HU plan as a reference. Results At D98 of the clinical target volume (CTV) and spinal cord‐D2cc, when the density of the large bowel was close to that of gas, there were significant differences compared to the reference plan (p < 0.05). By contrast, no significant difference was observed in stomach‐D2cc duodenum‐D2cc, small bowel‐D2cc, kidneys‐V18, and liver‐Dmean under any of the conditions. There were no cases in which the dose constraint of organs at risk, specified by our institution, was exceeded. Conclusion Density change in the large bowel was revealed to significantly affect the doses of the CTV and spinal cord during PT with SIB for LAPC. For beam arrangement, it is important to select a gantry angle that prevents the large bowel from passing as much as possible. If this is unavoidable, it is important to carefully observe the gas image on the beam path during daily image guidance and to provide adaptive re‐planning as needed.
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Affiliation(s)
- Yuki Narita
- Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima, Japan
| | - Takahiro Kato
- Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima, Japan.,School of Health Sciences, Fukushima Medical University, Fukushima, Japan
| | - Kimihiro Takemasa
- Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima, Japan
| | - Hiroki Sato
- Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima, Japan
| | - Tomohiro Ikeda
- Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima, Japan
| | - Takaomi Harada
- Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima, Japan
| | - Sho Oyama
- Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Fukushima, Japan
| | - Masao Murakami
- Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Fukushima, Japan
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Kubota Y, Okamoto M, Shiba S, Okazaki S, Matsui T, Li Y, Itabashi Y, Sakai M, Kubo N, Tsuda K, Ohno T, Nakano T. Robustness of daily dose for each beam angle and accumulated dose for inter-fractional anatomical changes in passive carbon-ion radiotherapy for pancreatic cancer: Bone matching versus tumor matching. Radiother Oncol 2021; 157:85-92. [PMID: 33515667 DOI: 10.1016/j.radonc.2021.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/09/2020] [Accepted: 01/09/2021] [Indexed: 02/02/2023]
Abstract
PURPOSE We aimed to assess the robustness of accumulated dose distributions for inter-fractional changes in passive carbon-ion radiotherapy for pancreatic cancer. METHODS Ninety-five daily CT image sets acquired after the treatment of eight patients with pancreatic cancer were used in this prospective study. Dose distributions with treatment beam fields were recalculated for bone matching (BM) and tumor matching (TM) positions on all daily CT images, the accumulated doses being calculated using deformable image registration methods. The prescribed dose was 55.2 Gy (relative biological effectiveness [RBE]) in 12 fractions. Dose volume parameters of V95 (%) for CTV and GTV, and D2cc (Gy(RBE)) for the stomach and duodenum were evaluated. RESULTS The medians (range) of CTV V95 (%) were 91.9 (86.1-100.0), 80.5 (56.1-90.6), and 86.4 (72.5-96.5) for the Plan, accumulated with BM and TM, respectively; GTV values (%) were 98.0 (85.7-100.0), 93.3 (65.7-99.9), and 96.2 (84.8-100.0), respectively. There were significant differences between all combinations apart from the Plan and TM for both targets. The values of stomach D2cc (Gy(RBE)) were 36.0 (16.9-43.4), 36.7 (17.9-45.0), and 35.2 (16.8-43.5), respectively; duodenum values (Gy(RBE)) were 25.2 (21.3-40.3), 30.1 (23.3-48.6), and 28.3 (20.4-50.6), respectively. There was a significant difference between the Plan and BM for duodenum only. CONCLUSIONS TM is recommended over BM because it can achieve higher target dose coverage than BM. Nevertheless, it is not enough in some cases. Further technical improvements are necessary to improve the target dose coverage.
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Affiliation(s)
| | | | | | | | - Toshiaki Matsui
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, Japan
| | - Yang Li
- Department of Radiation Oncology, Gunma University Graduate School of Medicine, Japan
| | | | - Makoto Sakai
- Gunma University Heavy Ion Medical Center, Japan
| | | | - Kazuhisa Tsuda
- Department of Radiology, Gunma University Hospital, Japan
| | - Tatsuya Ohno
- Gunma University Heavy Ion Medical Center, Japan
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