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Prezado Y, Grams M, Jouglar E, Martínez-Rovira I, Ortiz R, Seco J, Chang S. Spatially fractionated radiation therapy: a critical review on current status of clinical and preclinical studies and knowledge gaps. Phys Med Biol 2024; 69:10TR02. [PMID: 38648789 DOI: 10.1088/1361-6560/ad4192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
Spatially fractionated radiation therapy (SFRT) is a therapeutic approach with the potential to disrupt the classical paradigms of conventional radiation therapy. The high spatial dose modulation in SFRT activates distinct radiobiological mechanisms which lead to a remarkable increase in normal tissue tolerances. Several decades of clinical use and numerous preclinical experiments suggest that SFRT has the potential to increase the therapeutic index, especially in bulky and radioresistant tumors. To unleash the full potential of SFRT a deeper understanding of the underlying biology and its relationship with the complex dosimetry of SFRT is needed. This review provides a critical analysis of the field, discussing not only the main clinical and preclinical findings but also analyzing the main knowledge gaps in a holistic way.
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Affiliation(s)
- Yolanda Prezado
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, F-91400, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, F-91400, Orsay, France
- New Approaches in Radiotherapy Lab, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Instituto de investigación Sanitaria de Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, E-15706, Spain
- Oportunius Program, Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, A Coruña, Spain
| | - Michael Grams
- Department of Radiation Oncology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, United States of America
| | - Emmanuel Jouglar
- Institut Curie, PSL Research University, Department of Radiation Oncology, F-75005, Paris and Orsay Protontherapy Center, F-91400, Orsay, France
| | - Immaculada Martínez-Rovira
- Physics Department, Universitat Auto`noma de Barcelona, E-08193, Cerdanyola del Valle`s (Barcelona), Spain
| | - Ramon Ortiz
- University of California San Francisco, Department of Radiation Oncology, 1600 Divisadero Street, San Francisco, CA 94143, United States of America
| | - Joao Seco
- Division of Biomedical physics in Radiation Oncology, DKFZ-German Cancer Research Center, Heidelberg, Germany
- Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Sha Chang
- Dept of Radiation Oncology and Department of Biomedical Engineering, University of North Carolina School of Medicine, United States of America
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolin State University, United States of America
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2
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Zhang X, Griffin RJ, Galhardo EP, Penagaricano J. Feasibility Study of 3D-VMAT-Based GRID Therapy. Technol Cancer Res Treat 2022; 21:15330338221086420. [PMID: 35289202 DOI: 10.1177/15330338221086420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Spatially fractionated radiotherapy (GRID) could effectively de-bulk tumor volumes for shallow and deep-seated locally advanced tumors. A new treatment planning method using the three-dimensional-volumetric modulated arc therapy (VMAT) technique combined with a novel, software-generated, virtual GRID block (VGB) was developed which allows better conformity plans (VMAT-GRID) and maintain the GRID dosimetric characteristics. The dosimetric metrics calculated via the valley/peak ratio (Dmin/Dmax), D90/D10, gross tumor volume (GTV) mean dose (Dmean), GTV equivalent uniform dose (EUD), and normal tissue maximum dose. Methods: Twenty-five patients with tumor volumes ranging between 71.6 cc and 4683 cc at various tumor sites were retrospectively studied. The prescription was 20 Gy to the maximum point of GTV in a single fraction, and the VMAT-GRID plan was generated using 6 MV/10 MV flattening-filter-free beams. Results: The optimized VGB was designed with the median center-to-center distance of 27 mm, and 9 mm for the median diameter of the opening area in this study. These 2 values can be used to design any optimized VGB, the final VGB may be modified to generate a patient-specific VGB. The median GTV mean dose was 918 (877- 938) cGy, and the median GTV EUD dose was 818 (597-916) cGy. In terms of dose inhomogeneity, the median valley-to-peak dose ratio was 0.07 (0.02-0.26); and the median ratio of D90/D10 was 0.70 (0.38-0.94). For the organ-at-risk doses, there was a rapid dose drop-off in the normal tissue area immediately adjacent to the target, and the maximum global doses were all located inside the GTV. Conclusion: Our results indicated that the VMAT-GRID planning approach could successfully deliver dose with acceptable GRID dose metric while sparing the normal tissue especially in the region near the target due to the rapid dose drop-off and restricting maximum dose inside the target.
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Affiliation(s)
- Xin Zhang
- Department of Radiation Oncology, Boston Medical Center, 1836Boston University School of Medicine, Boston, MA, USA.,Department of Radiation Oncology, 12215University of Arkansas for Medical Science, Little Rock, AR, USA
| | - Robert J Griffin
- Department of Radiation Oncology, 12215University of Arkansas for Medical Science, Little Rock, AR, USA
| | - Edvaldo P Galhardo
- Department of Radiation Oncology, 12215University of Arkansas for Medical Science, Little Rock, AR, USA.,Department of Radiation Oncology, Genesis Care, Bradenton, FL, USA
| | - Jose Penagaricano
- Department of Radiation Oncology, 12215University of Arkansas for Medical Science, Little Rock, AR, USA.,Department of Radiation Oncology, 25301Moffitt Cancer Center, Tampa, FL, USA
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Cahoon P, Giacometti V, Casey F, Russell E, McGarry C, Prise KM, McMahon SJ. Investigating spatial fractionation and radiation induced bystander effects: a mathematical modelling approach. Phys Med Biol 2021; 66. [PMID: 34666318 DOI: 10.1088/1361-6560/ac3119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 10/19/2021] [Indexed: 11/12/2022]
Abstract
Radiation induced bystander effects (RIBEs) have been shown to cause death in cells receiving little or no physical dose. In standard radiotherapy, where uniform fields are delivered and all cells are directly exposed to radiation, this phenomenon can be neglected. However, the role of RIBEs may become more influential when heterogeneous fields are considered. Mathematical modelling can be used to determine how these heterogeneous fields might influence cell survival, but most established techniques account only for the direct effects of radiation. To gain a full appreciation of how non-uniform fields impact cell survival, it is also necessary to consider the indirect effects of radiation. In this work, we utilise a mathematical model that accounts for both the direct effects of radiation on cells and RIBEs. This model is used to investigate how spatially fractionated radiotherapy plans impact cell survivalin vitro. These predictions were compared to survival in normal and cancerous cells following exposure to spatially fractionated plans using a clinical linac. The model is also used to explore how spatially fractionated radiotherapy will impact tumour controlin vivo. Results suggest that spatially fractionated plans are associated with higher equivalent uniform doses than conventional uniform plans at clinically relevant doses. The model predicted only small changes changes in normal tissue complication probability, compared to the larger protection seen clinically. This contradicts a central paradigm of radiotherapy where uniform fields are assumed to maximise cell kill and may be important for future radiotherapy optimisation.
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Affiliation(s)
- Paul Cahoon
- Patrick G Johnson Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Valentina Giacometti
- Patrick G Johnson Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom.,Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland, United Kingdom
| | - Francis Casey
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland, United Kingdom.,Nottingham Radiotherapy Centre, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Emily Russell
- Patrick G Johnson Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Conor McGarry
- Patrick G Johnson Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom.,Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland, United Kingdom
| | - Kevin M Prise
- Patrick G Johnson Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Stephen J McMahon
- Patrick G Johnson Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
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4
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Romano M, Bravin A, Mittone A, Eckhardt A, Barbone GE, Sancey L, Dinkel J, Bartzsch S, Ricke J, Alunni-Fabbroni M, Hirner-Eppeneder H, Karpov D, Giannini C, Bunk O, Bouchet A, Ruf V, Giese A, Coan P. A Multi-Scale and Multi-Technique Approach for the Characterization of the Effects of Spatially Fractionated X-ray Radiation Therapies in a Preclinical Model. Cancers (Basel) 2021; 13:cancers13194953. [PMID: 34638437 PMCID: PMC8507698 DOI: 10.3390/cancers13194953] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/23/2021] [Accepted: 09/27/2021] [Indexed: 12/15/2022] Open
Abstract
The purpose of this study is to use a multi-technique approach to detect the effects of spatially fractionated X-ray Microbeam (MRT) and Minibeam Radiation Therapy (MB) and to compare them to seamless Broad Beam (BB) irradiation. Healthy- and Glioblastoma (GBM)-bearing male Fischer rats were irradiated in-vivo on the right brain hemisphere with MRT, MB and BB delivering three different doses for each irradiation geometry. Brains were analyzed post mortem by multi-scale X-ray Phase Contrast Imaging-Computed Tomography (XPCI-CT), histology, immunohistochemistry, X-ray Fluorescence (XRF), Small- and Wide-Angle X-ray Scattering (SAXS/WAXS). XPCI-CT discriminates with high sensitivity the effects of MRT, MB and BB irradiations on both healthy and GBM-bearing brains producing a first-time 3D visualization and morphological analysis of the radio-induced lesions, MRT and MB induced tissue ablations, the presence of hyperdense deposits within specific areas of the brain and tumor evolution or regression with respect to the evaluation made few days post-irradiation with an in-vivo magnetic resonance imaging session. Histology, immunohistochemistry, SAXS/WAXS and XRF allowed identification and classification of these deposits as hydroxyapatite crystals with the coexistence of Ca, P and Fe mineralization, and the multi-technique approach enabled the realization, for the first time, of the map of the differential radiosensitivity of the different brain areas treated with MRT and MB. 3D XPCI-CT datasets enabled also the quantification of tumor volumes and Ca/Fe deposits and their full-organ visualization. The multi-scale and multi-technique approach enabled a detailed visualization and classification in 3D of the radio-induced effects on brain tissues bringing new essential information towards the clinical implementation of the MRT and MB radiation therapy techniques.
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Affiliation(s)
- Mariele Romano
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität, Am Coulombwall 1, München, 85748 Garching, Germany; (M.R.); (A.E.); (G.E.B.)
| | - Alberto Bravin
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France; (A.B.); (A.M.); (D.K.)
- Department of Physics, Faculty of Physics, University of Milano-Bicocca, 20126 Milan, Italy
| | - Alberto Mittone
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France; (A.B.); (A.M.); (D.K.)
- CELLS-ALBA Synchrotron, 08290 Cerdanyola del Valles, Spain
| | - Alicia Eckhardt
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität, Am Coulombwall 1, München, 85748 Garching, Germany; (M.R.); (A.E.); (G.E.B.)
| | - Giacomo E. Barbone
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität, Am Coulombwall 1, München, 85748 Garching, Germany; (M.R.); (A.E.); (G.E.B.)
- Department of Radiology, University Hospital, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (J.D.); (J.R.); (M.A.-F.); (H.H.-E.)
| | - Lucie Sancey
- Centre de Recherche UGA/INSERM U1209/CNRS UMR5309, Institute for Advanced Biosciences, 38700 La Tronche, France;
| | - Julien Dinkel
- Department of Radiology, University Hospital, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (J.D.); (J.R.); (M.A.-F.); (H.H.-E.)
| | - Stefan Bartzsch
- Department of Radiation Oncology, School of Medicine, Technical University of Munich, Klinikum Rechts der Isar, 81675 Munich, Germany;
- Department of Radiation Sciences (DRS), Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Jens Ricke
- Department of Radiology, University Hospital, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (J.D.); (J.R.); (M.A.-F.); (H.H.-E.)
| | - Marianna Alunni-Fabbroni
- Department of Radiology, University Hospital, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (J.D.); (J.R.); (M.A.-F.); (H.H.-E.)
| | - Heidrun Hirner-Eppeneder
- Department of Radiology, University Hospital, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (J.D.); (J.R.); (M.A.-F.); (H.H.-E.)
| | - Dmitry Karpov
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France; (A.B.); (A.M.); (D.K.)
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland;
| | - Cinzia Giannini
- Institute of Crystallography, National Research Council, 70126 Bari, Italy;
| | - Oliver Bunk
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland;
| | - Audrey Bouchet
- Inserm U1296 Unit “Radiation: Defense, Health Environment”, 69008 Lyon, France;
| | - Viktoria Ruf
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (V.R.); (A.G.)
| | - Armin Giese
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (V.R.); (A.G.)
| | - Paola Coan
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität, Am Coulombwall 1, München, 85748 Garching, Germany; (M.R.); (A.E.); (G.E.B.)
- Department of Radiology, University Hospital, Ludwig-Maximilians-Universität, 81377 Munich, Germany; (J.D.); (J.R.); (M.A.-F.); (H.H.-E.)
- Correspondence:
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5
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Ferini G, Valenti V, Tripoli A, Illari SI, Molino L, Parisi S, Cacciola A, Lillo S, Giuffrida D, Pergolizzi S. Lattice or Oxygen-Guided Radiotherapy: What If They Converge? Possible Future Directions in the Era of Immunotherapy. Cancers (Basel) 2021; 13:cancers13133290. [PMID: 34209192 PMCID: PMC8268715 DOI: 10.3390/cancers13133290] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/23/2021] [Accepted: 06/26/2021] [Indexed: 12/31/2022] Open
Abstract
Palliative radiotherapy has a great role in the treatment of large tumor masses. However, treating a bulky disease could be difficult, especially in critical anatomical areas. In daily clinical practice, short course hypofractionated radiotherapy is delivered in order to control the symptomatic disease. Radiation fields generally encompass the entire tumor mass, which is homogeneously irradiated. Recent technological advances enable delivering a higher radiation dose in small areas within a large mass. This goal, previously achieved thanks to the GRID approach, is now achievable using the newest concept of LATTICE radiotherapy (LT-RT). This kind of treatment allows exploiting various radiation effects, such as bystander and abscopal effects. These events may be enhanced by the concomitant use of immunotherapy, with the latter being ever more successfully delivered in cancer patients. Moreover, a critical issue in the treatment of large masses is the inhomogeneous intratumoral distribution of well-oxygenated and hypo-oxygenated areas. It is well known that hypoxic areas are more resistant to the killing effect of radiation, hence the need to target them with higher aggressive doses. This concept introduces the "oxygen-guided radiation therapy" (OGRT), which means looking for suitable hypoxic markers to implement in PET/CT and Magnetic Resonance Imaging. Future treatment strategies are likely to involve combinations of LT-RT, OGRT, and immunotherapy. In this paper, we review the radiobiological rationale behind a potential benefit of LT-RT and OGRT, and we summarize the results reported in the few clinical trials published so far regarding these issues. Lastly, we suggest what future perspectives may emerge by combining immunotherapy with LT-RT/OGRT.
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Affiliation(s)
- Gianluca Ferini
- REM Radioterapia, Viagrande, I-95029 Catania, Italy; (V.V.); (A.T.)
- Correspondence: ; Tel.: +39-095-789-4581
| | - Vito Valenti
- REM Radioterapia, Viagrande, I-95029 Catania, Italy; (V.V.); (A.T.)
| | | | | | - Laura Molino
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy; (L.M.); (S.P.); (A.C.); (S.L.); (S.P.)
| | - Silvana Parisi
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy; (L.M.); (S.P.); (A.C.); (S.L.); (S.P.)
| | - Alberto Cacciola
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy; (L.M.); (S.P.); (A.C.); (S.L.); (S.P.)
| | - Sara Lillo
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy; (L.M.); (S.P.); (A.C.); (S.L.); (S.P.)
| | - Dario Giuffrida
- Medical Oncology Unit, Mediterranean Institute of Oncology, Viagrande, I-95029 Catania, Italy;
| | - Stefano Pergolizzi
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali Università di Messina, I-98100 Messina, Italy; (L.M.); (S.P.); (A.C.); (S.L.); (S.P.)
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Jiang L, Li X, Zhang J, Li W, Dong F, Chen C, Lin Q, Zhang C, Zheng F, Yan W, Zheng Y, Wu X, Xu B. Combined High-Dose LATTICE Radiation Therapy and Immune Checkpoint Blockade for Advanced Bulky Tumors: The Concept and a Case Report. Front Oncol 2021; 10:548132. [PMID: 33643893 PMCID: PMC7907519 DOI: 10.3389/fonc.2020.548132] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 12/14/2020] [Indexed: 01/22/2023] Open
Abstract
Although the combination of immune checkpoint blockades with high dose of radiation has indicated the potential of co-stimulatory effects, consistent clinical outcome has been yet to be demonstrated. Bulky tumors present challenges for radiation treatment to achieve high rate of tumor control due to large tumor sizes and normal tissue toxicities. As an alternative, spatially fractionated radiotherapy (SFRT) technique has been applied, in the forms of GRID or LATTICE radiation therapy (LRT), to safely treat bulky tumors. When used alone in a single or a few fractions, GRID or LRT can be best classified as palliative or tumor de-bulking treatments. Since only a small fraction of the tumor volume receive high dose in a SFRT treatment, even with the anticipated bystander effects, total tumor eradications are rare. Backed by the evidence of immune activation of high dose radiation, it is logical to postulate that the combination of High-Dose LATTICE radiation therapy (HDLRT) with immune checkpoint blockade would be effective and could subsequently lead to improved local tumor control without added toxicities, through augmenting the effects of radiation in-situ vaccine and T-cell priming. We herein present a case of non-small cell lung cancer (NSCLC) with multiple metastases. The patient received various types of palliative radiation treatments with combined chemotherapies and immunotherapies to multiple lesions. One of the metastatic lesions measuring 63.2 cc was treated with HDLRT combined with anti-PD1 immunotherapy. The metastatic mass regressed 77.84% over one month after the treatment, and had a complete local response (CR) five months after the treatment. No treatment-related side effects were observed during the follow-up exams. None of the other lesions receiving palliative treatments achieved CR. The dramatic differential outcome of this case lends support to the aforementioned postulate and prompts for further systemic clinical studies.
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Affiliation(s)
- Liuqing Jiang
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xiaobo Li
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Department of Medical Imaging Technology, College of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China.,Department of Medical Imaging, School of Clinical Medicine, Fujian Medical University, Fuzhou, China
| | - Jianping Zhang
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Wenyao Li
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Fangfen Dong
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Cheng Chen
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Department of Medical Imaging Technology, College of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China
| | - Qingliang Lin
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Department of Medical Imaging Technology, College of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China.,Department of Medical Imaging, School of Clinical Medicine, Fujian Medical University, Fuzhou, China
| | - Chonglin Zhang
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Fen Zheng
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Weisi Yan
- Department of Radiation Oncology, Thomas Jefferson Medical College, Philadelphia, PA, United States
| | - Yi Zheng
- Department of Medical Physics, Executive Medical Physics Associates, Miami, FL, United States
| | - Xiaodong Wu
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Department of Medical Physics, Executive Medical Physics Associates, Miami, FL, United States
| | - Benhua Xu
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, China.,Department of Medical Imaging Technology, College of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China.,Department of Medical Imaging, School of Clinical Medicine, Fujian Medical University, Fuzhou, China
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7
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Sheikh K, Hrinivich WT, Bell LA, Moore JA, Laub W, Viswanathan AN, Yan Y, McNutt TR, Meyer J. Comparison of treatment planning approaches for spatially fractionated irradiation of deep tumors. J Appl Clin Med Phys 2019; 20:125-133. [PMID: 31112629 PMCID: PMC6560243 DOI: 10.1002/acm2.12617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 04/01/2019] [Accepted: 04/27/2019] [Indexed: 12/02/2022] Open
Abstract
Purpose The purpose of this work was to compare the dosimetry and delivery times of 3D‐conformal (3DCRT)‐, volumetric modulated arc therapy (VMAT)‐, and tomotherapy‐based approaches for spatially fractionated radiation therapy for deep tumor targets. Methods Two virtual GRID phantoms were created consisting of 7 “target” cylinders (1‐cm diameter) aligned longitudinally along the tumor in a honey‐comb pattern, mimicking a conventional GRID block, with 2‐cm center‐to‐center spacing (GRID2 cm) and 3‐cm center‐to‐center spacing (GRID3 cm), all contained within a larger cylinder (8 and 10 cm in diameter for the GRID2 cm and GRID3 cm, respectively). In a single patient, a GRID3 cm structure was created within the gross tumor volume (GTV). Tomotherapy, VMAT (6 MV + 6 MV‐flattening‐filter‐free) and multi‐leaf collimator segment 3DCRT (6 MV) plans were created using commercially available software. Two tomotherapy plans were created with field widths (TOMO2.5 cm) 2.5 cm and (TOMO5 cm) 5 cm. Prescriptions for all plans were set to deliver a mean dose of 15 Gy to the GRID targets in one fraction. The mean dose to the GRID target and the heterogeneity of the dose distribution (peak‐to‐valley and peak‐to‐edge dose ratios) inside the GRID target were obtained. The volume of normal tissue receiving 7.5 Gy was determined. Results The peak‐to‐valley ratios for GRID2 cm/GRID3 cm/Patient were 2.1/2.3/2.8, 1.7/1.5/2.8, 1.7/1.9/2.4, and 1.8/2.0/2.8 for the 3DCRT, VMAT, TOMO5 cm, and TOMO2.5 cm plans, respectively. The peak‐to‐edge ratios for GRID2 cm/GRID3 cm/Patient were 2.8/3.2/5.4, 2.1/1.8/5.4, 2.0/2.2/3.9, 2.1/2.7/5.2 and for the 3DCRT, VMAT, TOMO5 cm, and TOMO2.5 cm plans, respectively. The volume of normal tissue receiving 7.5 Gy was lowest in the TOMO2.5 cm plan (GRID2 cm/GRID3 cm/Patient = 54 cm3/19 cm3/10 cm3). The VMAT plans had the lowest delivery times (GRID2 cm/GRID3 cm/Patient = 17 min/8 min/9 min). Conclusion Our results present, for the first time, preliminary evidence comparing IMRT‐GRID approaches which result in high‐dose “islands” within a target, mimicking what is achieved with a conventional GRID block but without high‐dose “tail” regions outside of the target. These approaches differ modestly in their ability to achieve high peak‐to‐edge ratios and also differ in delivery times.
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Affiliation(s)
- Khadija Sheikh
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - William T Hrinivich
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Leslie A Bell
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Joseph A Moore
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Wolfram Laub
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Akila N Viswanathan
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yulong Yan
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Todd R McNutt
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jeffrey Meyer
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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