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Modiri A, Vogelius I, Rechner LA, Nygård L, Bentzen SM, Specht L. Outcome-based multiobjective optimization of lymphoma radiation therapy plans. Br J Radiol 2021; 94:20210303. [PMID: 34541859 PMCID: PMC8553178 DOI: 10.1259/bjr.20210303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 09/02/2021] [Accepted: 09/06/2021] [Indexed: 02/04/2023] Open
Abstract
At its core, radiation therapy (RT) requires balancing therapeutic effects against risk of adverse events in cancer survivors. The radiation oncologist weighs numerous disease and patient-level factors when considering the expected risk-benefit ratio of combined treatment modalities. As part of this, RT plan optimization software is used to find a clinically acceptable RT plan delivering a prescribed dose to the target volume while respecting pre-defined radiation dose-volume constraints for selected organs at risk. The obvious limitation to the current approach is that it is virtually impossible to ensure the selected treatment plan could not be bettered by an alternative plan providing improved disease control and/or reduced risk of adverse events in this individual. Outcome-based optimization refers to a strategy where all planning objectives are defined by modeled estimates of a specific outcome's probability. Noting that various adverse events and disease control are generally incommensurable, leads to the concept of a Pareto-optimal plan: a plan where no single objective can be improved without degrading one or more of the remaining objectives. Further benefits of outcome-based multiobjective optimization are that quantitative estimates of risks and benefit are obtained as are the effects of choosing a different trade-off between competing objectives. Furthermore, patient-level risk factors and combined treatment modalities may be integrated directly into plan optimization. Here, we present this approach in the clinical setting of multimodality therapy for malignant lymphoma, a malignancy with marked heterogeneity in biology, target localization, and patient characteristics. We discuss future research priorities including the potential of artificial intelligence.
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Affiliation(s)
- Arezoo Modiri
- Department of Radiation Oncology, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Ivan Vogelius
- Department of Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Laura Ann Rechner
- Department of Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Lotte Nygård
- Department of Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Søren M Bentzen
- Department of Epidemiology and Public Health, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Lena Specht
- Department of Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Grassberger C, Shinnick D, Yeap BY, Tracy M, G Ellsworth S, Hess CB, Weyman EA, Gallotto SL, Lawell MP, Bajaj B, Ebb DH, Ioakeim-Ioannidou M, Loeffler JS, MacDonald SM, Tarbell NJ, Yock TI. Circulating Lymphocyte Counts Early During Radiation Therapy Are Associated With Recurrence in Pediatric Medulloblastoma. Int J Radiat Oncol Biol Phys 2021; 110:1044-1052. [PMID: 33556478 PMCID: PMC8238781 DOI: 10.1016/j.ijrobp.2021.01.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
PURPOSE Decreased peripheral lymphocyte counts are associated with survival after radiation therapy (RT) in several solid tumors, although they appear late during or after the radiation course and often correlate with other clinical factors. Here we investigate if absolute lymphocyte counts (ALCs) are independently associated with recurrence in pediatric medulloblastoma early during RT. METHODS AND MATERIALS We assessed 202 patients with medulloblastoma treated between 2000 and 2016 and analyzed ALC throughout therapy, focusing on both early markers (ALC during week 1 - ALCwk1; grade 3+ Lymphopenia during week 2 - Lymphopeniawk2) and late markers (ALC nadir). Uni- and multivariable regressions were used to assess association of clinical and treatment variables with ALC and of ALC with recurrence. RESULTS Thirty-six recurrences were observed, with a median time to recurrence of 1.6 years (range, 0.2-10.3) and 7.1 years median follow-up. ALC during RT was associated with induction chemotherapy (P < .001), concurrent carboplatin (P = .009), age (P = .01), and high-risk status (P = .05). On univariable analysis, high-risk disease (hazard ratio = 2.0 [1.06-3.9]; P = .03) and M stage≥1 (hazard ratio = 2.2 [1.1-4.4]) were associated with recurrence risk, as was lower ALC early during RT (ALCwk1, hazard ratio = 0.28 [0.12-0.65]; P = .003; Lymphopeniawk2, hazard ratio = 2.27 [1.1-4.6]; P = .02). Neither baseline ALC nor nadir correlated with outcome. These associations persisted when excluding carboplatin and pre-RT chemotherapy patients, and in the multivariable analysis accounting for confounders lymphocyte counts remained significant (ALCwk1, hazard-ratio = 0.23 [0.09-0.57]; P = .002; Lymphopeniawk2, hazard-ratio = 2.3 [1.1-4.8]; P = .03). CONCLUSIONS ALC during weeks 1 and 2 of RT was associated with recurrence, and low ALC is an independent prognostic factor in medulloblastoma. Strategies to mitigate the risk of radiation-induced lymphopenia should be considered.
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Affiliation(s)
- Clemens Grassberger
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
| | - Daniel Shinnick
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Beow Y Yeap
- Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Mark Tracy
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Susannah G Ellsworth
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Clayton B Hess
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Elizabeth A Weyman
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sara L Gallotto
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Miranda P Lawell
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Benjamin Bajaj
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - David H Ebb
- Pediatric Hematology/Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Myrsini Ioakeim-Ioannidou
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Pediatric Hematology/Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Jay S Loeffler
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shannon M MacDonald
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Nancy J Tarbell
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Torunn I Yock
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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3
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Dell'Oro M, Short M, Wilson P, Bezak E. Normal tissue tolerance amongst paediatric brain tumour patients- current evidence in proton radiotherapy. Crit Rev Oncol Hematol 2021; 164:103415. [PMID: 34242771 DOI: 10.1016/j.critrevonc.2021.103415] [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: 08/12/2020] [Revised: 04/28/2021] [Accepted: 07/04/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Proton radiotherapy (PT) is used increasingly for paediatric brain cancer patients. However, as demonstrated here, the knowledge on normal tissue dose constraints, to minimize side-effects, for this cohort is limited. METHODS A search strategy was systematically conducted on MEDLINE® database. 65 papers were evaluated ranging from 2013 to 2021. RESULTS Large variations in normal tissue tolerance and toxicity reporting across PT studies makes estimation of normal tissue dose constraints difficult, with the potential for significant late effects to go unmeasured. Mean dose delivered to the pituitary gland varies from 20 to 30 Gy across literature. Similarly, the hypothalamic dose delivery ranges from 20 to 54.6 Gy for paediatric patients. CONCLUSION There is a significant lack of radiobiological data for paediatric brain cancer patients undergoing proton therapy, often using data from x-ray radiotherapy and adult populations. The way forward is through standardisation of reporting in order to validate relevant dose constraints.
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Affiliation(s)
- Mikaela Dell'Oro
- Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia; Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia.
| | - Michala Short
- Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia
| | - Puthenparampil Wilson
- Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, SA 5000, Australia; UniSA STEM, University of South Australia, Adelaide, SA 5001, Australia
| | - Eva Bezak
- Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia; Department of Physics, University of Adelaide, Adelaide, SA 5005, Australia
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Ozawa N, Fukuzawa R, Furuya K. Mothers' Experiences about Decisions to Use Children's Proton Beam Therapy. CHILDREN-BASEL 2021; 8:children8040274. [PMID: 33918337 PMCID: PMC8066003 DOI: 10.3390/children8040274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 11/16/2022]
Abstract
Recently, proton beam therapy has been recommended in radiation therapy for child-hood cancer. However, facilities for children are limited, and parents who choose this treatment for their children face a variety of challenges. This study reveals mothers’ experiences about the decision to use the aforementioned therapy. A semi-structured interview was conducted with 16 mothers of children who received proton beam therapy in Japan, and a grounded theory approach was adopted. The results revealed that mothers were very worried about late complications concerning their children due to radiation. While the mothers strongly expected proton beam therapy to reduce the risk of late complications, they felt uncertainty and anxiety throughout the entire decision-making process. Despite having to deal with their feelings, they had to transfer to another hospital and prepare support for their children to begin treatment, and this put a lot of strain on them. From decision-making to start of treatment, these emotional fluctuations and the need for psychological support became apparent.
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Affiliation(s)
- Noriko Ozawa
- Faculty of Medicine, University of Tsukuba, Ibaraki 305-8577, Japan;
- Correspondence:
| | - Rieko Fukuzawa
- Faculty of Medicine, University of Tsukuba, Ibaraki 305-8577, Japan;
| | - Kayuri Furuya
- Faculty of Global Nursing, Iryo Sosei University, Chiba 277-0803, Japan;
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5
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Wilson LJ, Newhauser WD. Generalized approach for radiotherapy treatment planning by optimizing projected health outcome: preliminary results for prostate radiotherapy patients. Phys Med Biol 2021; 66:065007. [PMID: 33545710 DOI: 10.1088/1361-6560/abe3cf] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Research in cancer care increasingly focuses on survivorship issues, e.g. managing disease- and treatment-related morbidity and mortality occurring during and after treatment. This necessitates innovative approaches that consider treatment side effects in addition to tumor cure. Current treatment-planning methods rely on constrained iterative optimization of dose distributions as a surrogate for health outcomes. The goal of this study was to develop a generally applicable method to directly optimize projected health outcomes. We developed an outcome-based objective function to guide selection of the number, angle, and relative fluence weight of photon and proton radiotherapy beams in a sample of ten prostate-cancer patients by optimizing the projected health outcome. We tested whether outcome-optimized radiotherapy (OORT) improved the projected longitudinal outcome compared to dose-optimized radiotherapy (DORT) first for a statistically significant majority of patients, then for each individual patient. We assessed whether the results were influenced by the selection of treatment modality, late-risk model, or host factors. The results of this study revealed that OORT was superior to DORT. Namely, OORT maintained or improved the projected health outcome of photon- and proton-therapy treatment plans for all ten patients compared to DORT. Furthermore, the results were qualitatively similar across three treatment modalities, six late-risk models, and 10 patients. The major finding of this work was that it is feasible to directly optimize the longitudinal (i.e. long- and short-term) health outcomes associated with the total (i.e. therapeutic and stray) absorbed dose in all of the tissues (i.e. healthy and diseased) in individual patients. This approach enables consideration of arbitrary treatment factors, host factors, health endpoints, and times of relevance to cancer survivorship. It also provides a simpler, more direct approach to realizing the full beneficial potential of cancer radiotherapy.
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Affiliation(s)
- Lydia J Wilson
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001, United States of America
| | - Wayne D Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001, United States of America.,Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, LA 70809, United States of America
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Wilson LJ, Newhauser WD. Justification and optimization of radiation exposures: a new framework to aggregate arbitrary detriments and benefits. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:389-405. [PMID: 32556631 DOI: 10.1007/s00411-020-00855-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Myriad radiation effects, including benefits and detriments, complicate justifying and optimizing radiation exposures. The purpose of this study was to develop a comprehensive conceptual framework and corresponding quantitative methods to aggregate the detriments and benefits of radiation exposures to individuals, groups, and populations. In this study, concepts from the ICRP for low dose were integrated with clinical techniques focused on high dose to develop a comprehensive figure of merit (FOM) that takes into account arbitrary host- and exposure-related factors, endpoints, and time points. The study built on existing methods with three new capabilities: application to individuals, groups, and populations; extension to arbitrary numbers and types of endpoints; and inclusion of limitation, where relevant. The FOM was applied to three illustrative exposure situations: emergency response, diagnostic imaging, and cancer radiotherapy, to evaluate its utility in diverse settings. The example application to radiation protection revealed the FOM's utility in optimizing the benefits and risks to a population while keeping individual exposures below applicable regulatory limits. Examples in diagnostic imaging and cancer radiotherapy demonstrated the FOM's utility for guiding population- and patient-specific decisions in medical applications. The major finding of this work is that it is possible to quantitatively combine the benefits and detriments of any radiation exposure situation involving an individual or population to perform cost-effectiveness analyses using the ICRP key principles of radiation protection. This FOM fills a chronic gap in the application of radiation-protection theory, i.e., limitations of generalized frameworks to algorithmically justify and optimize radiation exposures. This new framework potentially enhances objective optimization and justification, especially in complex exposure situations.
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Affiliation(s)
- Lydia J Wilson
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803-4001, USA
| | - Wayne D Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, 70803-4001, USA.
- Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, LA, 70809, USA.
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Cardiac Toxicity After Craniospinal Irradiation: A Late Effect That May be Eliminated With Proton Therapy. J Pediatr Hematol Oncol 2018; 40:e330-e333. [PMID: 29200158 DOI: 10.1097/mph.0000000000001029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Craniospinal irradiation (CSI) is commonly required for pediatric patients with central nervous system malignancies. Traditionally, CSI is given using x-rays to deliver radiation to the brain and spine, exposing normal anterior structures, including heart, to unnecessary radiation. OBSERVATIONS We present a patient treated with x-ray CSI for medulloblastoma with spinal metastasis (3600 cGy CSI with focal boost to 5000 cGy), who subsequently developed significant cardiac toxicity, likely related to radiation exposure. CONCLUSIONS Spinal irradiation can cause significant cardiac risk due to exit dose through anterior structures. This toxicity may be avoided with proton therapy, which eliminates visceral exit dose.
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8
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Coban EA, Kasikci E, Karatas OF, Suakar O, Kuskucu A, Altunbek M, Türe U, Sahin F, Bayrak OF. Characterization of stem-like cells in a new astroblastoma cell line. Exp Cell Res 2017; 352:393-402. [DOI: 10.1016/j.yexcr.2017.02.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/06/2017] [Accepted: 02/19/2017] [Indexed: 01/06/2023]
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9
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Murphy H, Jaafari H, Dobrovolny HM. Differences in predictions of ODE models of tumor growth: a cautionary example. BMC Cancer 2016; 16:163. [PMID: 26921070 PMCID: PMC4768423 DOI: 10.1186/s12885-016-2164-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 02/14/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND While mathematical models are often used to predict progression of cancer and treatment outcomes, there is still uncertainty over how to best model tumor growth. Seven ordinary differential equation (ODE) models of tumor growth (exponential, Mendelsohn, logistic, linear, surface, Gompertz, and Bertalanffy) have been proposed, but there is no clear guidance on how to choose the most appropriate model for a particular cancer. METHODS We examined all seven of the previously proposed ODE models in the presence and absence of chemotherapy. We derived equations for the maximum tumor size, doubling time, and the minimum amount of chemotherapy needed to suppress the tumor and used a sample data set to compare how these quantities differ based on choice of growth model. RESULTS We find that there is a 12-fold difference in predicting doubling times and a 6-fold difference in the predicted amount of chemotherapy needed for suppression depending on which growth model was used. CONCLUSION Our results highlight the need for careful consideration of model assumptions when developing mathematical models for use in cancer treatment planning.
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Affiliation(s)
- Hope Murphy
- Department of Physics, Utica College, Utica, NY, USA.
| | - Hana Jaafari
- Department of Physics & Astronomy, Texas Christian University, 2800 S. University Drive, TX, 76129, Fort Worth, USA.
| | - Hana M Dobrovolny
- Department of Physics & Astronomy, Texas Christian University, 2800 S. University Drive, TX, 76129, Fort Worth, USA.
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Vigneron C, Entz-Werlé N, Lutz P, Spiegel A, Jannier S, Helfre S, Alapetite C, Coca A, Kehrli P, Noël G. [Evolution of the management of pediatric and adult medulloblastoma]. Cancer Radiother 2015; 19:347-57; quiz 358-9, 362. [PMID: 26141663 DOI: 10.1016/j.canrad.2015.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 01/05/2015] [Accepted: 03/02/2015] [Indexed: 10/23/2022]
Abstract
Medulloblastoma are cerebellar tumours belonging to the group of primitive neuroectodermal tumours (PNET) and are the most common malignant brain tumours of childhood. These tumours are rare and heterogeneous, requiring some multicentric prospective studies and multidisciplinary care. The classical therapeutic approaches are based on clinical, radiological and surgical data. They involve surgery, radiation therapy and chemotherapy. Some histological features were added to characterize risk. More recently, molecular knowledge has allowed to devise risk-adapted strategies and helped to define groups with good outcome and reduce long-term sequelae, improve the prognostic of high-risk medulloblastoma and develop new therapeutic tools.
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Affiliation(s)
- C Vigneron
- Département de radiothérapie, centre de lutte contre le cancer Paul-Strauss, 3, rue de la Porte-de-l'Hôpital, BP 42, 67065 Strasbourg cedex, France
| | - N Entz-Werlé
- Service d'oncologie pédiatrique, CHU Hautepierre, 1, avenue Molière, 67098 Strasbourg cedex, France
| | - P Lutz
- Service d'oncologie pédiatrique, CHU Hautepierre, 1, avenue Molière, 67098 Strasbourg cedex, France
| | - A Spiegel
- Service d'oncologie pédiatrique, CHU Hautepierre, 1, avenue Molière, 67098 Strasbourg cedex, France
| | - S Jannier
- Service d'oncologie pédiatrique, CHU Hautepierre, 1, avenue Molière, 67098 Strasbourg cedex, France
| | - S Helfre
- Département de radiothérapie, institut Curie, 26, rue d'Ulm, 75005 Paris, France
| | - C Alapetite
- Département de radiothérapie, institut Curie, 26, rue d'Ulm, 75005 Paris, France
| | - A Coca
- Service de neurochirurgie, CHU Hautepierre, 1, avenue Molière, 67098 Strasbourg cedex, France
| | - P Kehrli
- Service de neurochirurgie, CHU Hautepierre, 1, avenue Molière, 67098 Strasbourg cedex, France
| | - G Noël
- Département de radiothérapie, centre de lutte contre le cancer Paul-Strauss, 3, rue de la Porte-de-l'Hôpital, BP 42, 67065 Strasbourg cedex, France; Laboratoire EA 3430, fédération de médecine translationnelle de Strasbourg (FMTS), université de Strasbourg, 4, rue Kirschleger, 67085 Strasbourg cedex, France.
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Rechner LA, Eley JG, Howell RM, Zhang R, Mirkovic D, Newhauser WD. Risk-optimized proton therapy to minimize radiogenic second cancers. Phys Med Biol 2015; 60:3999-4013. [PMID: 25919133 PMCID: PMC4443860 DOI: 10.1088/0031-9155/60/10/3999] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Proton therapy confers substantially lower predicted risk of second cancer compared with photon therapy. However, no previous studies have used an algorithmic approach to optimize beam angle or fluence-modulation for proton therapy to minimize those risks. The objectives of this study were to demonstrate the feasibility of risk-optimized proton therapy and to determine the combination of beam angles and fluence weights that minimizes the risk of second cancer in the bladder and rectum for a prostate cancer patient. We used 6 risk models to predict excess relative risk of second cancer. Treatment planning utilized a combination of a commercial treatment planning system and an in-house risk-optimization algorithm. When normal-tissue dose constraints were incorporated in treatment planning, the risk model that incorporated the effects of fractionation, initiation, inactivation, repopulation and promotion selected a combination of anterior and lateral beams, which lowered the relative risk by 21% for the bladder and 30% for the rectum compared to the lateral-opposed beam arrangement. Other results were found for other risk models.
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Affiliation(s)
- Laura A. Rechner
- The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
- Present Address: Department of Radiation Oncology, Rigshospitalet, Blegdamsvej 9, 2100 København Ø, Denmark
| | - John G. Eley
- The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
| | - Rebecca M. Howell
- The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
| | - Rui Zhang
- The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
- Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Baton Rouge, LA 70803, USA
| | - Dragan Mirkovic
- The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
| | - Wayne D. Newhauser
- The University of Texas Health Science Center Houston, Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
- Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Baton Rouge, LA 70803, USA
- Department of Medical Physics, Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, LA 70809, USA
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12
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Reducing the cost of proton radiation therapy: the feasibility of a streamlined treatment technique for prostate cancer. Cancers (Basel) 2015; 7:688-705. [PMID: 25920039 PMCID: PMC4491679 DOI: 10.3390/cancers7020688] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/03/2015] [Accepted: 04/15/2015] [Indexed: 01/05/2023] Open
Abstract
Proton radiation therapy is an effective modality for cancer treatments, but the cost of proton therapy is much higher compared to conventional radiotherapy and this presents a formidable barrier to most clinical practices that wish to offer proton therapy. Little attention in literature has been paid to the costs associated with collimators, range compensators and hypofractionation. The objective of this study was to evaluate the feasibility of cost-saving modifications to the present standard of care for proton treatments for prostate cancer. In particular, we quantified the dosimetric impact of a treatment technique in which custom fabricated collimators were replaced with a multileaf collimator (MLC) and the custom range compensators (RC) were eliminated. The dosimetric impacts of these modifications were assessed for 10 patients with a commercial treatment planning system (TPS) and confirmed with corresponding Monte Carlo simulations. We assessed the impact on lifetime risks of radiogenic second cancers using detailed dose reconstructions and predictive dose-risk models based on epidemiologic data. We also performed illustrative calculations, using an isoeffect model, to examine the potential for hypofractionation. Specifically, we bracketed plausible intervals of proton fraction size and total treatment dose that were equivalent to a conventional photon treatment of 79.2 Gy in 44 fractions. Our results revealed that eliminating the RC and using an MLC had negligible effect on predicted dose distributions and second cancer risks. Even modest hypofractionation strategies can yield substantial cost savings. Together, our results suggest that it is feasible to modify the standard of care to increase treatment efficiency, reduce treatment costs to patients and insurers, while preserving high treatment quality.
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13
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Kornerup JS, Brodin NP, Björk-Eriksson T, Birk Christensen C, Kiil-Berthelsen A, Aznar MC, Hollensen C, Markova E, Munck Af Rosenschöld P. PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy. Br J Radiol 2014; 88:20140586. [PMID: 25494657 DOI: 10.1259/bjr.20140586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To investigate the impact of including fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). METHODS Target volumes were first delineated without and subsequently re-delineated with access to (18)F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP) and estimated risk of secondary cancer (SC). RESULTS Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. CONCLUSION Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing or decreasing irradiated volumes, suggesting that the long-term morbidity of RT in childhood would on average remain largely unaffected. ADVANCES IN KNOWLEDGE (18)F-FDG PET-based RT planning does not systematically change NTCP or SC risk for paediatric cancer patients compared with CT only. 3 out of 11 patients had a distinct change of target volumes when PET-guided planning was introduced. Dice and mismatch metrics are not sufficient to assess the consequences of target volume differences in the context of RT.
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Affiliation(s)
- J S Kornerup
- 1 Section of Radiotherapy, Department of Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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