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Chargari C, Escande A, Dupuis P, Thariat J. Reirradiation: A complex situation. Cancer Radiother 2022; 26:911-915. [PMID: 35987812 DOI: 10.1016/j.canrad.2022.06.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 10/15/2022]
Abstract
Reirradiation of a tumor recurrence or second cancer in a previously irradiated area is challenging due to lack of high-quality physical, radiobiological, clinical data and inherent substantial risks of toxicity with cumulative dose and uncertain tissue recovery. Yet, major advances have been made in radiotherapy techniques, that have the potential to achieve cure while limiting severe toxicity rates, but still much research is necessary to better appraise the therapeutic index in such a complex situation.
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Affiliation(s)
- C Chargari
- Radiation Oncology, Gustave Roussy Cancer Campus, Villejuif, France.
| | - A Escande
- Département universitaire de radiothérapie, centre Oscar-Lambret, 3, rue Frédéric-Combemale, 59000 Lille, France; Faculté de médecine Henri-Warembourg, université de Lille, 59000 Lille, France; UMR 9189, Centre de recherche en informatique, signal et automatique de Lille (Cristal), 59655 Villeneuve d'Ascq, France
| | - P Dupuis
- Léon Bérard Cancer Center, University of Lyon, 69373 Lyon, France
| | - J Thariat
- Francois Baclesse Cancer center. Laboratoire de Physique Corpusculaire/IN2P3-CNRS UMR 6534-ARCHADE, Unicaen-Université de Normandie, 14000 Caen, France
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2
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Abstract
New understandings of the biology of radiosurgery are considered. Differences from the radiobiology of fractionated radiotherapy are outlined. It is noted DNA damage alone is insufficient to account for the tissue changes which occur. Changes in blood vessels and immunological mechanisms are also involved. Tissue repair is more rapid than previously thought so that dose rate (the rate of delivery of radiation to the tissues) has been seen to be more important. The value of fractionation is examined. The effect of radiosurgery on normal brain (so called functional radiosurgery) is considered. The desired effects may be achieved by a focal stable destruction of brain from a high radiation dose. They may also be achieved using a lower dose which acts through the mechanism known as radiosurgical neuromodulation.
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Affiliation(s)
- Jeremy C Ganz
- Department of Neurosurgery, Haukeland University Hospital, Bergen, Norway.
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3
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Behrends C, Haussmann J, Kramer PH, Langendijk JA, Gottschlag H, Geismar D, Budach W, Timmermann B. Model-based comparison of organ at risk protection between VMAT and robustly optimised IMPT plans. Z Med Phys 2021; 31:5-15. [PMID: 33358063 DOI: 10.1016/j.zemedi.2020.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 09/07/2020] [Accepted: 09/18/2020] [Indexed: 11/15/2022]
Abstract
The comparison between intensity-modulated proton therapy (IMPT) and volume-modulated arc therapy (VMAT) plans, based on models of normal tissue complication probabilities (NTCP), can support the choice of radiation modality. IMPT irradiation plans for 50 patients with head and neck tumours originally treated with photon therapy have been robustly optimised against density and setup uncertainties. The dose distribution has been calculated with a Monte Carlo (MC) algorithm. The comparison of the plans was based on dose-volume parameters in organs at risk (OARs) and NTCP-calculations for xerostomia, sticky saliva, dysphagia and tube feeding using Langendijk's model-based approach. While the dose distribution in the target volumes is similar, the IMPT plans show better protection of OARs. Therefore, it is not the high dose confirmation that constitutes the advantage of protons, but it is the reduction of the mid-to-low dose levels compared to photons. This work investigates to what extent the advantages of proton radiation are beneficial for the patient's post-therapeutic quality of life (QoL). As a result, approximately one third of the patients examined benefit significantly from proton therapy with regard to possible late side effects. Clinical data is needed to confirm the model-based calculations.
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Affiliation(s)
- Carina Behrends
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; Heinrich-Heine-University, Düsseldorf, Germany; West German Cancer Centre (WTZ), Essen, Germany.
| | - Jan Haussmann
- Department of Radiation Oncology, Heinrich-Heine-University, Düsseldorf, Germany
| | - P-H Kramer
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany
| | - Johannes A Langendijk
- Department of Radiation Oncology, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Holger Gottschlag
- Department of Radiation Oncology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Dirk Geismar
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; Department of Particle Therapy, University Hospital Essen, Essen, Germany
| | - Wilfried Budach
- Department of Radiation Oncology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Beate Timmermann
- West German Proton Therapy Centre Essen (WPE), Essen, Germany; West German Cancer Centre (WTZ), Essen, Germany; Department of Particle Therapy, University Hospital Essen, Essen, Germany; German Cancer Consortium (DKTK), Germany
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4
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Voshart DC, Wiedemann J, van Luijk P, Barazzuol L. Regional Responses in Radiation-Induced Normal Tissue Damage. Cancers (Basel) 2021; 13:cancers13030367. [PMID: 33498403 PMCID: PMC7864176 DOI: 10.3390/cancers13030367] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/16/2021] [Accepted: 01/18/2021] [Indexed: 12/16/2022] Open
Abstract
Normal tissue side effects remain a major concern in radiotherapy. The improved precision of radiation dose delivery of recent technological developments in radiotherapy has the potential to reduce the radiation dose to organ regions that contribute the most to the development of side effects. This review discusses the contribution of regional variation in radiation responses in several organs. In the brain, various regions were found to contribute to radiation-induced neurocognitive dysfunction. In the parotid gland, the region containing the major ducts was found to be critical in hyposalivation. The heart and lung were each found to exhibit regional responses while also mutually affecting each other's response to radiation. Sub-structures critical for the development of side effects were identified in the pancreas and bladder. The presence of these regional responses is based on a non-uniform distribution of target cells or sub-structures critical for organ function. These characteristics are common to most organs in the body and we therefore hypothesize that regional responses in radiation-induced normal tissue damage may be a shared occurrence. Further investigations will offer new opportunities to reduce normal tissue side effects of radiotherapy using modern and high-precision technologies.
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Affiliation(s)
- Daniëlle C. Voshart
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands; (D.C.V.); (J.W.)
- Department of Biomedical Sciences of Cells & Systems–Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Julia Wiedemann
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands; (D.C.V.); (J.W.)
- Department of Biomedical Sciences of Cells & Systems–Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Peter van Luijk
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands; (D.C.V.); (J.W.)
- Department of Biomedical Sciences of Cells & Systems–Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
- Correspondence: (P.v.L.); (L.B.)
| | - Lara Barazzuol
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands; (D.C.V.); (J.W.)
- Department of Biomedical Sciences of Cells & Systems–Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
- Correspondence: (P.v.L.); (L.B.)
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5
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Patel G, Mandal A, Choudhary S, Mishra R, Shahi U, Mishra H. Myths, facts and scope of spinal cord tolerance dose revision in Intensity modulated SIB treatment of locally advanced head and neck cancer: A dosimetrical and radiobiological demonstration. Cancer Radiother 2020; 25:8-12. [PMID: 33293203 DOI: 10.1016/j.canrad.2020.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/02/2020] [Accepted: 05/09/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To explore the possibility of revising the spinal cord tolerance dose in Simultaneously Integrated Boost (SIB) intensity modulated treatment plan of locally advanced head and neck (H&N) cancer and assessment of achieved planning gain due to the revision. In SIB regimen, the Organ at Risk (OARs) tolerance dose is equally distributed throughout the treatment. Clinicians have usually considered the spinal cord tolerance to be the same as in conventional technique. However, in SIB fractionation regimen with intensity modulation treatment, the spinal cord may receive a physical dose of 45Gy, with much lesser dose per fraction than 2Gy per fraction. So when the dose of spinal cord is distributed throughout the treatment, the tolerance dose limit of physical dose can be considered higher than the usual conventional dose limits. In this study, an attempt has been made to explore the possibilities of dose escalation and treatment planning benefits while exploiting this "Window of Opportunity (WoO)" of increase in spinal cord and Planning Risk Volume (PRV) spinal cord tolerance dose. MATERIAL AND METHODS A total of 12 patients CT data set along with approved structure set of H&N cancer used for treatment planning in. Three independent SIB VMAT plans named as SPC, SPR and SPDE were generated for the 12 patients. First plan (SPC) was generated by considering standard spinal cord tissue constraint of maximum dose of 45Gy and PRV spinal cord maximum dose 50Gy as per QUANTEC summary and second plan (SPR) was generated considering spinal cord tissue constraint of maximum dose 52.50Gy and PRV spinal cord maximum dose 56.35Gy while optimization and dose calculation. The objectives for rest of the Organ at Risk (OAR) were kept same in both the plans during optimization and dose calculation. The SPC plan was copied for creation of third plan (SPDE) in which dose was escalated by increasing dose per fraction for target volumes such that dose to spinal cord reached a maximum dose of 52.50Gy and PRV spinal cord maximum dose of 56.35Gy. In this plan there have been changes to only dose per fraction, however dose optimization and dose calculation have not been performed. Radiobiological parameters TCP and NTCP were also calculated by using indigenously developed software. RESULTS Considering the increase of spinal cord tolerance dose as "window of opportunity", a sufficient escalation in physical dose, Biological Effective Dose (BED) and Tumor Control Probability (TCP) was observed for all target volumes with acceptable level of NTCP values. CONCLUSION Sufficient dose escalation and increased in TCP for target volumes or effective planning benefits can be achieved by revising the spinal cord tolerance dose in intensity modulated SIB treatment of locally advanced H&N cancers.
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Affiliation(s)
- G Patel
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, BHU, Varanasi, India.
| | - A Mandal
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, BHU, Varanasi, India.
| | - S Choudhary
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, BHU, Varanasi, India.
| | - R Mishra
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, BHU, Varanasi, India.
| | - U Shahi
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, BHU, Varanasi, India.
| | - H Mishra
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, BHU, Varanasi, India.
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6
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Zaer H, Glud AN, Schneider BM, Lukacova S, Vang Hansen K, Adler JR, Høyer M, Jensen MB, Hansen R, Hoffmann L, Worm ES, Sørensen JCH, Orlowski D. Radionecrosis and cellular changes in small volume stereotactic brain radiosurgery in a porcine model. Sci Rep 2020; 10:16223. [PMID: 33004849 PMCID: PMC7529917 DOI: 10.1038/s41598-020-72876-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/08/2020] [Indexed: 12/25/2022] Open
Abstract
Stereotactic radiosurgery (SRS) has proven an effective tool for the treatment of brain tumors, arteriovenous malformation, and functional conditions. However, radiation-induced therapeutic effect in viable cells in functional SRS is also suggested. Evaluation of the proposed modulatory effect of irradiation on neuronal activity without causing cellular death requires the knowledge of radiation dose tolerance at very small tissue volume. Therefore, we aimed to establish a porcine model to study the effects of ultra-high radiosurgical doses in small volumes of the brain. Five minipigs received focal stereotactic radiosurgery with single large doses of 40–100 Gy to 5–7.5 mm fields in the left primary motor cortex and the right subcortical white matter, and one animal remained as unirradiated control. The animals were followed-up with serial MRI,
PET scans, and histology 6 months post-radiation. We observed a dose-dependent relation of the histological and MRI changes at 6 months post-radiation. The necrotic lesions were seen in the grey matter at 100 Gy and in white matter at 60 Gy. Furthermore, small volume radiosurgery at different dose levels induced vascular, as well as neuronal cell changes and glial cell remodeling.
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Affiliation(s)
- Hamed Zaer
- Centre for Experimental Neuroscience (CENSE), Department of Neurosurgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, indgang J, Plan 1, J118-125, (Krydspunkt 116), 8200, Aarhus N, Denmark. .,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Andreas Nørgaard Glud
- Centre for Experimental Neuroscience (CENSE), Department of Neurosurgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, indgang J, Plan 1, J118-125, (Krydspunkt 116), 8200, Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Bret M Schneider
- Zap Surgical Systems, Inc., San Carlos, CA, USA.,Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Slávka Lukacova
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Oncology and Radiation Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Kim Vang Hansen
- Department of Nuclear Medicine and PET Center, Institute of Clinical Medicine, Aarhus University and Hospital, Aarhus, Denmark
| | - John R Adler
- Zap Surgical Systems, Inc., San Carlos, CA, USA.,Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Morten Høyer
- Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Morten Bjørn Jensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Oncology and Radiation Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Rune Hansen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Oncology and Radiation Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Lone Hoffmann
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Oncology and Radiation Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Esben Schjødt Worm
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Oncology and Radiation Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Chr Hedemann Sørensen
- Centre for Experimental Neuroscience (CENSE), Department of Neurosurgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, indgang J, Plan 1, J118-125, (Krydspunkt 116), 8200, Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Dariusz Orlowski
- Centre for Experimental Neuroscience (CENSE), Department of Neurosurgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, indgang J, Plan 1, J118-125, (Krydspunkt 116), 8200, Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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7
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Liu EK, Silverman JS, Sulman EP. Stereotactic Radiation for Treating Primary and Metastatic Neoplasms of the Spinal Cord. Front Oncol 2020; 10:907. [PMID: 32582555 PMCID: PMC7295942 DOI: 10.3389/fonc.2020.00907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/11/2020] [Indexed: 12/14/2022] Open
Abstract
Stereotactic radiation treatment can be used to treat spinal cord neoplasms in patients with either unresectable lesions or residual disease after surgical resection. While treatment guidelines have been suggested for epidural lesions, the utility of stereotactic radiation for intradural and intramedullary malignancies is still debated. Prior reports have suggested that stereotactic radiation approaches can be used for effective tumor control and symptom management. Treatment-related toxicity has been documented in rare subsets of patients, though the incidences of injury are not directly correlated with higher radiation doses. Further studies are needed to assess the factors that influence the risk of radiation-induced myelopathy when treating spinal cord neoplasms with stereotactic radiation, which can include, but may not be limited to, maximum dose, dose-fractionation, irradiated volume, tumor location, histology and treatment history. This review will discuss evidence for current treatment approaches.
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Affiliation(s)
- Elisa K Liu
- Departments of Radiation Oncology, NYU Grossman School of Medicine, New York, NY, United States
| | - Joshua S Silverman
- Departments of Radiation Oncology, NYU Grossman School of Medicine, New York, NY, United States.,Departments of Neurosurgery, NYU Grossman School of Medicine, New York, NY, United States
| | - Erik P Sulman
- Departments of Radiation Oncology, NYU Grossman School of Medicine, New York, NY, United States.,Brain and Spine Tumor Center, Laura and Isaac Perlmutter Cancer Center, NYU Langone Health, New York, NY, United States
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8
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Lomax AJ. Myths and realities of range uncertainty. Br J Radiol 2020; 93:20190582. [PMID: 31778317 PMCID: PMC7066970 DOI: 10.1259/bjr.20190582] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 11/01/2019] [Accepted: 11/24/2019] [Indexed: 12/25/2022] Open
Abstract
Range uncertainty is a much discussed topic in proton therapy. Although a very real aspect of proton therapy, its magnitude and consequences are sometimes misunderstood or overestimated. In this article, the sources and consequences of range uncertainty are reviewed, a number of myths associated with the effect discussed with the aim of putting range uncertainty into clinical context and attempting to de-bunk some of the more exaggerated claims made as to its consequences.
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Affiliation(s)
- Antony John Lomax
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland and Department of Physics, ETH Zurich, Switzerland
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9
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Spinal Nerve Tolerance to Single-Session Stereotactic Ablative Radiation Therapy. Int J Radiat Oncol Biol Phys 2019; 104:845-851. [DOI: 10.1016/j.ijrobp.2019.03.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/19/2019] [Accepted: 03/25/2019] [Indexed: 12/31/2022]
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10
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Nagle PW, van Goethem MJ, Kempers M, Kiewit H, Knopf A, Langendijk JA, Brandenburg S, van Luijk P, Coppes RP. In vitro biological response of cancer and normal tissue cells to proton irradiation not affected by an added magnetic field. Radiother Oncol 2019; 137:125-129. [PMID: 31085392 DOI: 10.1016/j.radonc.2019.04.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/19/2019] [Accepted: 04/23/2019] [Indexed: 01/26/2023]
Abstract
To optimize beam delivery and conformality of proton therapy, MRI integration has been proposed. Therefore, we investigated if proton irradiation in a magnetic field would change biological responses. Our data in cancer cell lines and stem cell-derived organoid models suggest that a magnetic field does not modify the biological response.
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Affiliation(s)
- Peter W Nagle
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology, University Medical Center Groningen, University of Groningen, The Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands; Department of Surgical Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Marc-Jan van Goethem
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands; KVI Center for Advanced Radiation Technology, University of Groningen, The Netherlands
| | - Marco Kempers
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Harry Kiewit
- KVI Center for Advanced Radiation Technology, University of Groningen, The Netherlands
| | - Antje Knopf
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Johannes A Langendijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Sytze Brandenburg
- KVI Center for Advanced Radiation Technology, University of Groningen, The Netherlands
| | - Peter van Luijk
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology, University Medical Center Groningen, University of Groningen, The Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Rob P Coppes
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology, University Medical Center Groningen, University of Groningen, The Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands.
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11
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Volume effects in radiosurgical spinal cord dose tolerance: how small is too small? ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s13566-018-0371-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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12
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Xue J, Emami B, Grimm J, Kubicek GJ, Asbell SO, Lanciano R, Welsh JS, Peng L, Quon H, Laub W, Gui C, Spoleti N, Das IJ, Goldman HW, Redmond KJ, Kleinberg LR, Brady LW. Clinical evidence for dose tolerance of the central nervous system in hypofractionated radiotherapy. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s13566-018-0367-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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13
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Nagle PW, Hosper NA, Barazzuol L, Jellema AL, Baanstra M, van Goethem MJ, Brandenburg S, Giesen U, Langendijk JA, van Luijk P, Coppes RP. Lack of DNA Damage Response at Low Radiation Doses in Adult Stem Cells Contributes to Organ Dysfunction. Clin Cancer Res 2018; 24:6583-6593. [PMID: 30135147 DOI: 10.1158/1078-0432.ccr-18-0533] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 06/08/2018] [Accepted: 08/17/2018] [Indexed: 11/16/2022]
Abstract
PURPOSE Radiotherapy for head and neck cancer may result in serious side effects, such as hyposalivation, impairing the patient's quality of life. Modern radiotherapy techniques attempt to reduce the dose to salivary glands, which, however, results in low-dose irradiation of the tissue stem cells. Here we assess the low-dose sensitivity of tissue stem cells and the consequences for tissue function. EXPERIMENTAL DESIGN Postirradiation rat salivary gland secretory function was determined after pilocarpine induction. Murine and patient-derived salivary gland and thyroid gland organoids were irradiated and clonogenic survival was assessed. The DNA damage response (DDR) was analyzed in organoids and modulated using different radiation modalities, chemical inhibition, and genetic modification. RESULTS Relative low-dose irradiation to the high-density stem cell region of rat salivary gland disproportionally impaired function. Hyper-radiosensitivity at doses <1 Gy, followed by relative radioresistance at doses ≥1 Gy, was observed in salivary gland and thyroid gland organoid cultures. DDR modulation resulted in diminished, or even abrogated, relative radioresistance. Furthermore, inhibition of the DDR protein ATM impaired DNA repair after 1 Gy, but not 0.25 Gy. Irradiation of patient-derived salivary gland organoid cells showed similar responses, whereas a single 1 Gy dose to salivary gland-derived stem cells resulted in greater survival than clinically relevant fractionated doses of 4 × 0.25 Gy. CONCLUSIONS We show that murine and human glandular tissue stem cells exhibit a dose threshold in DDR activation, resulting in low-dose hyper-radiosensitivity, with clinical implications in radiotherapy treatment planning. Furthermore, our results from patient-derived organoids highlight the potential of organoids to study normal tissue responses to radiation.
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Affiliation(s)
- Peter W Nagle
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Nynke A Hosper
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Lara Barazzuol
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Anne L Jellema
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Mirjam Baanstra
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Marc-Jan van Goethem
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.,KVI Center for Advanced Radiation Technology, University of Groningen, Groningen, the Netherlands
| | - Sytze Brandenburg
- KVI Center for Advanced Radiation Technology, University of Groningen, Groningen, the Netherlands
| | - Ulrich Giesen
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany
| | - Johannes A Langendijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Peter van Luijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Rob P Coppes
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands. .,Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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14
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Saager M, Peschke P, Welzel T, Huang L, Brons S, Grün R, Scholz M, Debus J, Karger CP. Late normal tissue response in the rat spinal cord after carbon ion irradiation. Radiat Oncol 2018; 13:5. [PMID: 29325596 PMCID: PMC5765675 DOI: 10.1186/s13014-017-0950-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/29/2017] [Indexed: 12/17/2022] Open
Abstract
Background The present work summarizes the research activities on radiation-induced late effects in the rat spinal cord carried out within the “clinical research group ion beam therapy” funded by the German Research Foundation (DFG, KFO 214). Methods and materials Dose–response curves for the endpoint radiation-induced myelopathy were determined at 6 different positions (LET 16–99 keV/μm) within a 6 cm spread-out Bragg peak using either 1, 2 or 6 fractions of carbon ions. Based on the tolerance dose TD50 of carbon ions and photons, the relative biological effectiveness (RBE) was determined and compared with predictions of the local effect model (LEM I and IV). Within a longitudinal magnetic resonance imaging (MRI)-based study the temporal development of radiation-induced changes in the spinal cord was characterized. To test the protective potential of the ACE (angiotensin converting enzyme)-inhibitor ramipril™, an additional dose–response experiment was performed. Results The RBE-values increased with LET and the increase was found to be larger for smaller fractional doses. Benchmarking the RBE-values as predicted by LEM I and LEM IV with the measured data revealed that LEM IV is more accurate in the high-LET, while LEM I is more accurate in the low-LET region. Characterization of the temporal development of radiation-induced changes with MRI demonstrated a shorter latency time for carbon ions, reflected on the histological level by an increased vessel perforation after carbon ion as compared to photon irradiations. For the ACE-inhibitor ramipril™, a mitigative rather than protective effect was found. Conclusions This comprehensive study established a large and consistent RBE data base for late effects in the rat spinal cord after carbon ion irradiation which will be further extended in ongoing studies. Using MRI, an extensive characterization of the temporal development of radiation-induced alterations was obtained. The reduced latency time for carbon ions is expected to originate from a dynamic interaction of various complex pathological processes. A dominant observation after carbon ion irradiation was an increase in vessel perforation preferentially in the white matter. To enable a targeted pharmacological intervention more details of the molecular pathways, responsible for the development of radiation-induced myelopathy are required.
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Affiliation(s)
- Maria Saager
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany. .,Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. .,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.
| | - Peter Peschke
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Clinical Cooperation Unit Molecular Radiooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Thomas Welzel
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Lifi Huang
- Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Stephan Brons
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
| | - Rebecca Grün
- Department of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Michael Scholz
- Department of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Christian P Karger
- Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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15
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Emphasis on Repair, Not Just Avoidance of Injury, Facilitates Prudent Stereotactic Ablative Radiotherapy. Semin Radiat Oncol 2017; 27:378-392. [DOI: 10.1016/j.semradonc.2017.04.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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16
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Chargari C, Maroun P, Louvel G, Drouet M, Riccobono D, François S, Dhermain F, Cosset JM, Deutsch É. [Repair and time-dose factor: The example of spinal cord irradiation]. Cancer Radiother 2017; 21:547-553. [PMID: 28888745 DOI: 10.1016/j.canrad.2017.07.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 07/05/2017] [Indexed: 01/31/2023]
Abstract
The question whether a reirradiation is possible, with either curative of palliative intent, is a frequent issue and a true therapeutic challenge, in particular for a critical organ sensitive to cumulative dose, such as the spinal cord. Preclinical experimental data, based on debatable models that are hardly transferable to patients, suggest that there is a possibility of reirradiation, beyond the classical threshold for dose constraints, taking into account the "time-dose factor". Although the underlying biological mechanisms are however uncertain, scarce clinical data seem to confirm that the tolerance of spinal cord to reirradiation does exist, provided that a particular attention to total dose is given. In the context where modern stereotactic irradiation facilities expand therapeutic perspectives, we review the literature on possibilities of reirradiation, through the example of spinal cord reirradiation.
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Affiliation(s)
- C Chargari
- Département de radiothérapie, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Université Paris-Saclay, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Radiothérapie moléculaire UMR 1030, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Effets biologiques des rayonnements, Institut de recherche biomédicale des armées, D19, 91220 Brétigny-sur-Orge, France; École du Val-de-Grâce, place Alphonse-Laveran, 75005 Paris, France.
| | - P Maroun
- Département de radiothérapie, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Université Paris-Saclay, 114, rue Édouard-Vaillant, 94800 Villejuif, France
| | - G Louvel
- Département de radiothérapie, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Université Paris-Saclay, 114, rue Édouard-Vaillant, 94800 Villejuif, France
| | - M Drouet
- Effets biologiques des rayonnements, Institut de recherche biomédicale des armées, D19, 91220 Brétigny-sur-Orge, France
| | - D Riccobono
- Effets biologiques des rayonnements, Institut de recherche biomédicale des armées, D19, 91220 Brétigny-sur-Orge, France
| | - S François
- Effets biologiques des rayonnements, Institut de recherche biomédicale des armées, D19, 91220 Brétigny-sur-Orge, France
| | - F Dhermain
- Département de radiothérapie, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Université Paris-Saclay, 114, rue Édouard-Vaillant, 94800 Villejuif, France
| | - J-M Cosset
- Centre Charlebourg-La Défense, groupe Amethyst, 65, avenue Foch, 92250 La Garenne-Colombes, France
| | - É Deutsch
- Département de radiothérapie, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Université Paris-Saclay, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Radiothérapie moléculaire UMR 1030, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France
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17
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Zschaeck S, Wust P, Graf R, Wlodarczyk W, Schild R, Thieme AH, Weihrauch M, Budach V, Ghadjar P. Spinal cord constraints in the era of high-precision radiotherapy : Retrospective analysis of 62 spinal/paraspinal lesions with possible infringements of spinal cord constraints within a minimal volume. Strahlenther Onkol 2017; 193:561-569. [PMID: 28466154 DOI: 10.1007/s00066-017-1138-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/07/2017] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Current constraints aim to minimize the risk of radiation myelitis by the use of restrictive maximal spinal cord doses, commonly 50 Gy. However, several studies suggested that a dose-volume effect could exist. Based on these observations, we evaluated patients receiving potentially excessive doses to the spinal cord within minimal volumes. PATIENTS AND METHODS Patients receiving radiotherapy between June 2010 and May 2015 using the NovalisTM (Varian, Palo Alto, CA, USA; Brainlab, Heimstetten, Germany) radiosurgery system were retrospectively analyzed. A total of 56 patients with 62 treated lesions that had been prescribed radiation doses close to the spinal cord potentially higher than the common 50 Gy 2‑Gy equivalent-dose (EQD2) constraint were selected for further analysis. Of these patients, 26 with 31 lesions had no history of previous irradiation, while 30 patients with 31 lesions had been previously irradiated within the treatment field. RESULTS According to different dose evaluation approaches (spinal canal, spinal cord contour), 16 and 10 out of 31 primary irradiated lesions infringed constraints. For the 16 lesions violating spinal canal doses, the maximum doses ranged from 50.5 to 61.9 Gy EQD2. Reirradiated lesions had an average and median cumulative dose of 70.5 and 69 Gy, respectively. Dose drop-off was steep in both groups. Median overall survival was 17 months. No radiation myelitis or radiomorphological alterations were observed during follow-up. CONCLUSION This study adds to the increasing body of evidence indicating that excessive spinal cord doses within a minimal volume, especially in a reirradiation setting with topographically distinct high-point doses, may be given to patients after careful evaluation of treatment- and tumor-associated risks.
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Affiliation(s)
- Sebastian Zschaeck
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany.
| | - Peter Wust
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Reinhold Graf
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Waldemar Wlodarczyk
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Reinhard Schild
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Alexander Henry Thieme
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Mirko Weihrauch
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Volker Budach
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Pirus Ghadjar
- Klinik für Radioonkologie und Strahlentherapie, Charité Centrum Tumormedizin CC14, Augustenburger Platz 1, 13353, Berlin, Germany
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18
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Purvis TE, Goodwin CR, Lubelski D, Laufer I, Sciubba DM. Review of stereotactic radiosurgery for intradural spine tumors. CNS Oncol 2017; 6:131-138. [DOI: 10.2217/cns-2016-0039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Stereotactic radiosurgery (SRS) has become an increasingly popular treatment modality for spinal tumors due to its noninvasive and targeted approach. Whether SRS has the promise of relieving pretreatment symptoms and providing local tumor control for patients with intradural spine tumors is still debated. This review explores the current literature on SRS treatment for both metastatic and benign intradural tumors, with a focus on differential use for intramedullary and intradural extramedullary neoplasms. Although mortality rates from underlying malignant disease remain high, SRS may benefit patients with spinal metastatic lesions. Benign tumors have shown a promising response to SRS therapy with low rates of complications. Larger studies are necessary to determine the indications and outcome profile of SRS for intradural spinal neoplasms.
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Affiliation(s)
- Taylor E Purvis
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - C Rory Goodwin
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel Lubelski
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ilya Laufer
- Department of Neurosurgery, Memorial Sloan–Kettering Hospital, New York, NY, USA
| | - Daniel M Sciubba
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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19
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Saager M, Glowa C, Peschke P, Brons S, Grün R, Scholz M, Huber PE, Debus J, Karger CP. The relative biological effectiveness of carbon ion irradiations of the rat spinal cord increases linearly with LET up to 99 keV/μm. Acta Oncol 2016; 55:1512-1515. [PMID: 27827542 DOI: 10.1080/0284186x.2016.1250947] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Maria Saager
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Christin Glowa
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Peter Peschke
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Clinical Cooperation Unit Molecular Radiooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan Brons
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany
| | - Rebecca Grün
- Department of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Michael Scholz
- Department of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Peter E. Huber
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Clinical Cooperation Unit Molecular Radiooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Christian P. Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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20
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Sahgal A, Chou D, Ames C, Ma L, Lamborn K, Huang K, Chuang C, Aiken A, Petti P, Weinstein P, Larson D. Image-Guided Robotic Stereotactic Body Radiotherapy for Benign Spinal Tumors: The University of California San Francisco Preliminary Experience. Technol Cancer Res Treat 2016; 6:595-604. [DOI: 10.1177/153303460700600602] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We evaluate our preliminary experience using the Cyberknife® Radiosurgery System in treating benign spinal tumors. A retrospective review of 16 consecutively treated patients, comprising 19 benign spinal tumors, was performed. Histologic types included neurofibroma [11], chordoma [4], hemangioma [2], and meningioma [2]. Three patients had Neurofibromatosis Type 1 (NF1). Only one tumor, recurrent chordoma, had been previously irradiated, and as such not considered in the local failure analysis. Local failure, for the remaining 18 tumors, was based clinically on symptom progression and/or tumor enlargement based on imaging. Indications for spine stereotactic body radiotherapy (SBRT) consisted of either adjuvant to subtotal resection (5/19), primary treatment alone (12/19), boost following external beam radiotherapy (1/19), and salvage following previous radiation (1/19). Median tumor follow-up is 25 months (2–37), and one patient (with NF1) died at 12 months from a stroke. The median total dose, number of fractions, and prescription isodose was 21 Gy (10–30 Gy), 3 fx (1–5 fx), 80% (42–87%). The median tumor volume was 7.6 cc (0.2–274.1 cc). The median V100 (volume V receiving 100% of the prescribed dose) and maximum tumor dose was 95% (77–100%) and 26.7 Gy (15.4–59.7 Gy), respectively. Three tumors progressed at 2, 4, and 36 months post-SR (n=18). Two tumors were neurofibromas (both in NF1 patients), and the third was an intramedullary hemangioblastoma. Based on imaging, two tumors had MRI documented progression, three had regressed, and 13 were unchanged (n=18). With short follow-up, local control following Cyberknife spine SBRT for benign spinal tumors appear acceptable.
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Affiliation(s)
- Arjun Sahgal
- Department of Radiation Oncology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Dean Chou
- Department of Neurologic Surgery University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Christopher Ames
- Department of Neurologic Surgery University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Lijun Ma
- Department of Radiation Oncology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Kathleen Lamborn
- Department of Epidemiology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Kim Huang
- Department of Radiation Oncology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Cynthia Chuang
- Department of Radiation Oncology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Ashley Aiken
- Department of Radiology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Paula Petti
- Department of Radiation Oncology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - Phil Weinstein
- Department of Neurologic Surgery University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
| | - David Larson
- Department of Radiation Oncology University of California San Francisco 505 Parnassus Avenue San Francisco, CA 94143, USA
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21
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Hernández-Durán S, Hanft S, Komotar RJ, Manzano GR. The role of stereotactic radiosurgery in the treatment of intramedullary spinal cord neoplasms: a systematic literature review. Neurosurg Rev 2015. [PMID: 26219855 DOI: 10.1007/s10143-015-0654-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Advances in imaging technology and microsurgical techniques have made microsurgical resection the treatment of choice in cases of symptomatic intramedullary tumors. The use of stereotactic radiosurgery (SRS) for spinal tumors is a recent development, and its application to intramedullary lesions is debated. We conducted a literature search through PubMed's MeSH system, compiling information regarding intramedullary neoplasms treated by SRS. We compiled histology, tumor location and size, treatment modality, radiation dose, fractionation, radiation-induced complications, follow-up, and survival. Ten papers reporting on 52 patients with 70 tumors were identified. Metastatic lesions accounted for 33%, while 67% were primary ones. Tumor location was predominantly cervical (53%), followed by thoracic (33%). Mean volume was 0.55 cm(3) (95% confidence interval (CI), 0.26-0.83). Preferred treatment modality was CyberKnife® (87%), followed by Novalis® (7%) and linear particle accelerator (LINAC) (6%). Mean radiation dose was 22.14 Gy (95% CI, 20.75-23.53), with mean fractionation of 4 (95% CI, 3-5). Three hemangioblastomas showed cyst enlargement. Symptom improvement or stabilization was seen in all but two cases. Radionecrotic spots adjacent to treated areas were seen at autopsy in four lesions, without clinical manifestations. Overall, clinical and radiological outcomes were favorable. Although surgery remains the treatment of choice for symptomatic intramedullary lesions, SRS can be a safe and effective option in selected cases. While this review suggests the overall safety and efficacy of SRS in the management of intramedullary tumors, future studies need randomized, homogeneous patient populations followed over a longer period to provide more robust evidence in its favor.
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Affiliation(s)
- Silvia Hernández-Durán
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Neuroanatomy, University of Costa Rica School of Medicine, San José, Costa Rica
| | - Simon Hanft
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Ricardo J Komotar
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Glen R Manzano
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
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22
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Saager M, Glowa C, Peschke P, Brons S, Grün R, Scholz M, Huber PE, Debus J, Karger CP. Split dose carbon ion irradiation of the rat spinal cord: Dependence of the relative biological effectiveness on dose and linear energy transfer. Radiother Oncol 2015. [PMID: 26197953 DOI: 10.1016/j.radonc.2015.07.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To measure the relative biological effectiveness (RBE) of carbon ions relative to 15 MeV photons in the rat spinal cord for different linear energy transfers (LET) to validate model calculations. METHODS AND MATERIALS The cervical spinal cord of rats was irradiated with 2 fractions of carbon ions at six positions of a 6 cm spread-out Bragg-peak (SOBP, 16-99 keV/μm). TD50-values (dose at 50% complication probability) were determined from dose-response curves for the endpoint radiation induced myelopathy (paresis grade II) within 300 days after irradiation. Using previously published TD50-values for photons (Karger et al., 2006; Debus et al., 2003), RBE-values were determined and compared with predictions of two versions of the local effect model (LEM I and IV). RESULTS TD50-values for paresis grade II were 26.7 ± 0.4 Gy (16 keV/μm), 24.0 ± 0.3 Gy (21 keV/μm), 22.5 ± 0.3 Gy (36 keV/μm), 20.1 ± 1.2 Gy (45 keV/μm), 17.7 ± 0.3 Gy (66 keV/μm), and 14.9 ± 0.3 Gy (99 keV/μm). RBE-values increased from 1.28 ± 0.03 (16 keV/μm) up to 2.30 ± 0.06 at 99 keV/μm. At the applied high fractional doses, LEM I fits best at 16 keV/μm and deviates progressively toward higher LETs while LEM IV agrees best at 99 keV/μm and shows increasing deviations, especially below 66 keV/μm. CONCLUSIONS The measured data improve the knowledge on the accuracy of RBE-calculations for carbon ions.
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Affiliation(s)
- Maria Saager
- Dept. of Radiation Oncology, University Hospital of Heidelberg, Germany; Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Christin Glowa
- Dept. of Radiation Oncology, University Hospital of Heidelberg, Germany; Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Peter Peschke
- Clinical Cooperation Unit Molecular Radiooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan Brons
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
| | - Rebecca Grün
- Dept. of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Michael Scholz
- Dept. of Biophysics, Helmholtz Center for Heavy Ion Research (GSI), Darmstadt, Germany
| | - Peter E Huber
- Dept. of Radiation Oncology, University Hospital of Heidelberg, Germany; Clinical Cooperation Unit Molecular Radiooncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jürgen Debus
- Dept. of Radiation Oncology, University Hospital of Heidelberg, Germany
| | - Christian P Karger
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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23
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Lee SH, Lee KC, Choi J, Ahn SH, Lee SH, Sung KH, Kil SH. Clinical applicability of biologically effective dose calculation for spinal cord in fractionated spine stereotactic body radiation therapy. Radiol Oncol 2015; 49:185-91. [PMID: 26029031 PMCID: PMC4387996 DOI: 10.1515/raon-2015-0008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/05/2015] [Indexed: 12/25/2022] Open
Abstract
Background. The aim of the study was to investigate whether biologically effective dose (BED) based on linear-quadratic model can be used to estimate spinal cord tolerance dose in spine stereotactic body radiation therapy (SBRT) delivered in 4 or more fractions. Patients and methods. Sixty-three metastatic spinal lesions in 47 patients were retrospectively evaluated. The most frequently prescribed dose was 36 Gy in 4 fractions. In planning, we tried to limit the maximum dose to the spinal cord or cauda equina less than 50% of prescription or 45 Gy2/2. BED was calculated using maximum point dose of spinal cord. Results. Maximum spinal cord dose per fraction ranged from 2.6 to 6.0 Gy (median 4.3 Gy). Except 4 patients with 52.7, 56.4, 62.4, and 67.9 Gy2/2, equivalent total dose in 2-Gy fraction of the patients was not more than 50 Gy2/2 (12.1–67.9, median 32.0). The ratio of maximum spinal cord dose to prescription dose increased up to 82.2% of prescription dose as epidural spinal cord compression grade increased. No patient developed grade 2 or higher radiation-induced spinal cord toxicity during follow-up period of 0.5 to 53.9 months. Conclusions. In fractionated spine SBRT, BED can be used to estimate spinal cord tolerance dose, provided that the dose per fraction to the spinal cord is moderate, e.g. < 6.0 Gy. It appears that a maximum dose of up to 45–50 Gy2/2 to the spinal cord is tolerable in 4 or more fractionation regimen.
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Affiliation(s)
- Seung Heon Lee
- Department of Radiation Oncology; Gachon University Gil Medical Center, Republic of Korea
| | - Kyu Chan Lee
- Department of Radiation Oncology; Gachon University Gil Medical Center, Republic of Korea
| | - Jinho Choi
- Department of Radiation Oncology; Gachon University Gil Medical Center, Republic of Korea
| | - So Hyun Ahn
- Department of Radiation Oncology; Gachon University Gil Medical Center, Republic of Korea
| | - Seok Ho Lee
- Department of Radiation Oncology; Gachon University Gil Medical Center, Republic of Korea
| | - Ki Hoon Sung
- Department of Radiation Oncology; Gachon University Gil Medical Center, Republic of Korea
| | - Se Hee Kil
- Gachon Medical Research Institute, Gachon University Gil Medical Center, Republic of Korea
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Corticospinal tract-sparing intensity-modulated radiotherapy treatment planning. Rep Pract Oncol Radiother 2014; 19:310-6. [DOI: 10.1016/j.rpor.2014.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 11/30/2013] [Accepted: 01/23/2014] [Indexed: 11/19/2022] Open
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Carbon Ion Irradiation of the Rat Spinal Cord: Dependence of the Relative Biological Effectiveness on Linear Energy Transfer. Int J Radiat Oncol Biol Phys 2014; 90:63-70. [DOI: 10.1016/j.ijrobp.2014.05.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/02/2014] [Accepted: 05/06/2014] [Indexed: 11/22/2022]
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Tan W, Han G, Wei S, Hu D. Sparing functional anatomical structures during intensity-modulated radiotherapy: an old problem, a new solution. Future Oncol 2014; 10:1863-72. [PMID: 23987920 DOI: 10.2217/fon.13.172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
ABSTRACT During intensity-modulated radiotherapy, an organ is usually assumed to be functionally homogeneous and, generally, its anatomical and spatial heterogeneity with respect to radiation response are not taken into consideration. However, advances in imaging and radiation techniques as well as an improved understanding of the radiobiological response of organs have raised the possibility of sparing the critical functional structures within various organs at risk during intensity-modulated radiotherapy. Here, we discuss these structures, which include the critical brain structure, or neural nuclei, and the nerve fiber tracts in the CNS, head and neck structures related to radiation-induced salivary and swallowing dysfunction, and functional structures in the heart and lung. We suggest that these structures can be used as potential surrogate organs at risk in order to minimize their radiation dose and/or irradiated volume without compromising the dose coverage of the target volume during radiation treatment.
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Affiliation(s)
- Wenyong Tan
- Department of Radiation Oncology, Hubei Cancer Hospital, 116 South Road, Zhuodaoquan, Wuhan 430079, China
| | - Guang Han
- Department of Radiation Oncology, Hubei Cancer Hospital, 116 South Road, Zhuodaoquan, Wuhan 430079, China
| | - Shaozhong Wei
- Department of Gastrointestinal & Genitourinary Oncology, Hubei Cancer Hospital, 116 South Road, Zhuodaoquan, Wuhan 430079, China
| | - Desheng Hu
- Department of Radiation Oncology, Hubei Cancer Hospital, 116 South Road, Zhuodaoquan, Wuhan 430079, China
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Dörr W, Herrmann T, Baumann M. Application of organ tolerance dose-constraints in clinical studies in radiation oncology. Strahlenther Onkol 2014; 190:621-4, 626-7. [PMID: 24604558 DOI: 10.1007/s00066-014-0613-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 01/30/2014] [Indexed: 02/07/2023]
Abstract
In modern radiation oncology, tolerance dose-constraints for organs at risk (OAR) must be considered for treatment planning, but particularly in order to design clinical studies. Tolerance dose tables, however, only address one aspect of the therapeutic ratio of any clinical study, i.e., the limitation of adverse events, but not the desired potential improvement in the tumor effect of a novel treatment strategy. A sensible application of "tolerance doses" in a clinical situation requires consideration of various critical aspects addressed here: definition of tolerance dose, specification of an endpoint/symptom, consideration of radiation quality and irradiation protocol, exposed volume and dose distribution, and patient-related factors of radiosensitivity. The currently most comprehensive estimates of OAR radiation tolerance are in the QUANTEC compilations (2010). However, these tolerance dose values must only be regarded as a rough orientation and cannot answer the relevant question for the patients, i.e., if the study can achieve a therapeutic advantage; this can obviously be answered only by the final scientific analysis of the study results. Despite all limitations, the design of clinical studies should currently refer to the QUANTEC values for appreciation of the risk of complications, if needed supplemented by one's own data or further information from the literature. The implementation of a consensus on the safety interests of the patients and on an application and approval process committed to progress in medicine, with transparent quality-assuring requirements with regard to the structural safeguarding of the study activities, plays a central role in clinical research in radiation oncology.
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Affiliation(s)
- Wolfgang Dörr
- Dept. of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Comprehensive Cancer Center, Medical University/AKH Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria,
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Paganetti H, van Luijk P. Biological considerations when comparing proton therapy with photon therapy. Semin Radiat Oncol 2013; 23:77-87. [PMID: 23473684 DOI: 10.1016/j.semradonc.2012.11.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Owing to the limited availability of data on the outcome of proton therapy, treatments are generally optimized based on broadly available data on photon-based treatments. However, the microscopic pattern of energy deposition of protons differs from that of photons, leading to a different biological effect. Consequently, proton therapy needs a correction factor (relative biological effectiveness) to relate proton doses to photon doses, and currently, a generic value is used. Moreover, the macroscopic distribution of dose in proton therapy differs compared with photon treatments. Although this may offer new opportunities to reduce dose to normal tissues, it raises the question whether data obtained from photon-based treatments offer sufficient information on dose-volume effects to optimally use unique features of protons. In addition, there are potential differences in late effects due to low doses of secondary radiation outside the volume irradiated by the primary beam. This article discusses the controversies associated with these 3 issues when comparing proton and photon therapy.
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Affiliation(s)
- Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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Uh J, Merchant TE, Li Y, Feng T, Gajjar A, Ogg RJ, Hua C. Differences in brainstem fiber tract response to radiation: a longitudinal diffusion tensor imaging study. Int J Radiat Oncol Biol Phys 2013; 86:292-7. [PMID: 23474114 DOI: 10.1016/j.ijrobp.2013.01.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 01/17/2013] [Accepted: 01/25/2013] [Indexed: 10/27/2022]
Abstract
PURPOSE To determine whether radiation-induced changes in white matter tracts are uniform across the brainstem. METHODS AND MATERIALS We analyzed serial diffusion tensor imaging data, acquired before radiation therapy and over 48 to 72 months of follow-up, from 42 pediatric patients (age 6-20 years) with medulloblastoma. FSL software (FMRIB, Oxford, UK) was used to calculate fractional anisotropy (FA) and axial, radial, and mean diffusivities. For a consistent identification of volumes of interest (VOIs), the parametric maps of each patient were transformed to a standard brain space (MNI152), on which we identified VOIs including corticospinal tract (CST), medial lemniscus (ML), transverse pontine fiber (TPF), and middle cerebellar peduncle (MCP) at the level of pons. Temporal changes of DTI parameters in VOIs were compared using a linear mixed effect model. RESULTS Radiation-induced white matter injury was marked by a decline in FA after treatment. The decline was often accompanied by decreased axial diffusivity, increased radial diffusivity, or both. This implied axonal damage and demyelination. We observed that the magnitude of the changes was not always uniform across substructures of the brainstem. Specifically, the changes in DTI parameters for TPF were more pronounced than in other regions (P<.001 for FA) despite similarities in the distribution of dose. We did not find a significant difference among CST, ML, and MCP in these patients (P>.093 for all parameters). CONCLUSIONS Changes in the structural integrity of white matter tracts, assessed by DTI, were not uniform across the brainstem after radiation therapy. These results support a role for tract-based assessment in radiation treatment planning and determination of brainstem tolerance.
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Affiliation(s)
- Jinsoo Uh
- Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
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Radiation induced brain injury: assessment of white matter tracts in a pre-clinical animal model using diffusion tensor MR imaging. J Neurooncol 2013; 112:9-15. [PMID: 23334608 DOI: 10.1007/s11060-012-1031-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 12/26/2012] [Indexed: 01/16/2023]
Abstract
We aim to study radiation induced white matter injury in a pre-clinical model using Diffusion tensor MR imaging (DTI). Nineteen 12-week old Sprague-Dawley rats were irradiated to the right hemisphere using a linear accelerator. The dose distribution map was coregistered to the DTI map to generate the actual radiation dose to each white matter tract. Rats underwent longitudinal DTI scans at five time points from 4 to 48 weeks post-radiation with histological evaluations. Fractional anisotropy (FA) of the external capsule, fornix, cerebral peduncle, anterior commissure, optic tract and optic nerve was evaluated. Radiation dose was highest at the ipsilateral external capsule and fornix (29.4 ± 1.3 and 29.8 ± 1.1 Gy, respectively). Optic nerve received 50 % dose to the external capsule and other white matter tracts received 80 % dose. Significantly lower FA was firstly found in the ipsilateral external capsule at 4 weeks post-radiation and in the ipsilateral fornix at 40 weeks post-radiation compared to the contralateral side. Significantly lower FA was found in contralateral optic nerve compared to ipsilateral optic nerve at 48 weeks post-radiation despite ipsilateral optic nerves receiving higher radiation dose than contralateral optic nerve (p = 0.021). No differences were found in other white matter regions until 48 weeks. Histology indicated demyelination, axonal degeneration and coagulative necrosis in all injured white matter. DTI can serve as a promising tool for assessment of radiation induced white matter injury and regional radiosensitivity of white matter tracts.
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31
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Laissue JA, Bartzsch S, Blattmann H, Bräuer-Krisch E, Bravin A, Dalléry D, Djonov V, Hanson AL, Hopewell JW, Kaser-Hotz B, Keyriläinen J, Laissue PP, Miura M, Serduc R, Siegbahn AE, Slatkin DN. Response of the rat spinal cord to X-ray microbeams. Radiother Oncol 2013; 106:106-11. [DOI: 10.1016/j.radonc.2012.12.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 12/07/2012] [Accepted: 12/11/2012] [Indexed: 11/26/2022]
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Medin PM, Foster RD, van der Kogel AJ, Sayre JW, McBride WH, Solberg TD. Spinal cord tolerance to single-session uniform irradiation in pigs: implications for a dose-volume effect. Radiother Oncol 2013; 106:101-5. [PMID: 22985780 PMCID: PMC3526692 DOI: 10.1016/j.radonc.2012.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/31/2012] [Accepted: 08/14/2012] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE This study was performed to test the hypothesis that spinal cord radiosensitivity is significantly modified by uniform versus laterally non-uniform dose distributions. MATERIALS AND METHODS A uniform dose distribution was delivered to a 4.5-7.0 cm length of cervical spinal cord in 22 mature Yucatan minipigs for comparison with a companion study in which a laterally non-uniform dose was given [1]. Pigs were allocated into four dose groups with mean maximum spinal cord doses of 17.5 ± 0.1 Gy (n=7), 19.5 ± 0.2 Gy (n=6), 22.0 ± 0.1 Gy (n=5), and 24.1 ± 0.2 Gy (n=4). The study endpoint was motor neurologic deficit determined by a change in gait within one year. Spinal cord sections were stained with a Luxol fast blue/periodic acid Schiff combination. RESULTS Dose-response curves for uniform versus non-uniform spinal cord irradiation were nearly identical with ED(50)'s (95% confidence interval) of 20.2 Gy (19.1-25.8) and 20.0 Gy (18.3-21.7), respectively. No neurologic change was observed for either dose distribution when the maximum spinal cord dose was ≤ 17.8 Gy while all animals experienced deficits at doses ≥ 21.8 Gy. CONCLUSION No dose-volume effect was observed in pigs for the dose distributions studied and the endpoint of motor neurologic deficit; however, partial spinal cord irradiation resulted in less debilitating neurologic morbidity and histopathology.
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Affiliation(s)
- Paul M Medin
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX 75390-8542, USA.
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Daly ME, Luxton G, Choi CY, Gibbs IC, Chang SD, Adler JR, Soltys SG. Normal Tissue Complication Probability Estimation by the Lyman-Kutcher-Burman Method Does Not Accurately Predict Spinal Cord Tolerance to Stereotactic Radiosurgery. Int J Radiat Oncol Biol Phys 2012; 82:2025-32. [DOI: 10.1016/j.ijrobp.2011.03.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 01/26/2011] [Accepted: 03/11/2011] [Indexed: 11/29/2022]
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Gerszten PC, Quader M, Novotny J, Flickinger JC. Radiosurgery for Benign Tumors of the Spine: Clinical Experience and Current Trends. Technol Cancer Res Treat 2012; 11:133-9. [DOI: 10.7785/tcrt.2012.500242] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In distinction to the development of the clinical indications for intracranial radiosurgery, spine radiosurgery's initial primary focus was and still remains the treatment of malignant disease. The role of stereotactic radiosurgery for the treatment of intracranial benign tumors has been well established. However, there is much less experience and much more controversy regarding the use of radiosurgery for the treatment of benign tumors of the spine. This study presents the clinical experience and current trends of radiosurgery in the treatment paradigm of benign tumors of the spine as part of a dedicated spine radiosurgery program. Forty consecutive benign spine tumors were treated using cone beam computed tomography (CBCT) image guidance technology for target localization. Lesion location included 13 cervical, 9 thoracic, 11 lumbar, and 7 sacral tumors. Thirty-four cases (85%) were intradural. The most common tumor histologies were schwannoma (15 cases), neurofibroma (7 cases), and meningioma (8 cases). Eighteen cases (45%) had previously undergone open surgical resection, and 4 lesions (10%) had previously been treated with conventional fractionated external beam irradiation techniques. This cohort was compared to a prior institutional experience of 73 consecutive benign spine tumors treated with radiosurgery. No subacute or long term spinal cord or cauda equina toxicity occurred during the follow-up period (median 26 months). Radiosurgery was used as the primary treatment modality in 22 cases (55%) and for recurrence after prior open surgical resection in 18 cases (45%). The mean prescribed dose to the gross tumor volume (GTV) was 14 Gy (range 11 to 17) delivered in a single fraction in 35 cases. In 5 cases in which the tumor was found to be intimately associated with the spinal cord with distortion of the spinal cord itself, the prescribed dose to the GTV was 18 to 21 Gy delivered in 3 fractions. The GTV ranged from 0.37 to 94.5 cm3 (mean 13.2 cm3, median 5.1 cm3). No evidence of tumor growth was seen on serial imaging in any case. Compared to the prior cohort, there was a trend towards increased patient age, GTV, and use of radiosurgery in the post-surgical setting, as well as a simultaneous decrease in the prescription dose. Radiosurgery is a safe and clinically effective treatment alternative for benign spinal neoplasms. While surgical extirpation is currently felt to be the best initial treatment option for most benign spinal tumors, spine radiosurgery has been demonstrated to have long-term clinical and radiographic benefit for the treatment of such lesions. In a similar manner in which spine radiosurgery has become a primary treatment option for a variety of intracranial benign tumors, radiosurgery may become the most favorable treatment alternative for similar histologies when found in the spine. The application of radiosurgery for non-neoplastic spine disease deserves future investigation.
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Affiliation(s)
- Peter C. Gerszten
- Departments of Neurological Surgery and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Mubina Quader
- Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Josef Novotny
- Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - John C. Flickinger
- Departments of Neurological Surgery and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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Daly ME, Choi CY, Gibbs IC, Adler JR, Chang SD, Lieberson RE, Soltys SG. Tolerance of the Spinal Cord to Stereotactic Radiosurgery: Insights From Hemangioblastomas. Int J Radiat Oncol Biol Phys 2011; 80:213-20. [DOI: 10.1016/j.ijrobp.2010.01.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 01/19/2010] [Accepted: 01/21/2010] [Indexed: 10/18/2022]
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Medin PM, Boike TP. Spinal cord tolerance in the age of spinal radiosurgery: lessons from preclinical studies. Int J Radiat Oncol Biol Phys 2011; 79:1302-9. [PMID: 21183290 PMCID: PMC3074505 DOI: 10.1016/j.ijrobp.2010.10.052] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 10/19/2010] [Accepted: 10/25/2010] [Indexed: 11/15/2022]
Abstract
Clinical implementation of spinal radiosurgery has increased rapidly in recent years, but little is known regarding human spinal cord tolerance to single-fraction irradiation. In contrast, preclinical studies in single-fraction spinal cord tolerance have been ongoing since the 1970s. The influences of field length, dose rate, inhomogeneous dose distributions, and reirradiation have all been investigated. This review summarizes literature regarding single-fraction spinal cord tolerance in preclinical models with an emphasis on practical clinical significance. The outcomes of studies that incorporate uniform irradiation are surprisingly consistent among multiple small- and large-animal models. Extensive investigation of inhomogeneous dose distributions in the rat has demonstrated a significant dose-volume effect while preliminary results from one pig study are contradictory. Preclinical spinal cord dose-volume studies indicate that dose distribution is more critical than the volume irradiated suggesting that neither dose-volume histogram analysis nor absolute volume constraints are effective in predicting complications. Reirradiation data are sparse, but results from guinea pig, rat, and pig studies are consistent with the hypothesis that the spinal cord possesses a large capacity for repair. The mechanisms behind the phenomena observed in spinal cord studies are not readily explained and the ability of dose response models to predict outcomes is variable underscoring the need for further investigation. Animal studies provide insight into the phenomena and mechanisms of radiosensitivity but the true significance of animal studies can only be discovered through clinical trials.
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Affiliation(s)
- Paul M Medin
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX 75390-9183, USA.
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Medin PM, Foster RD, van der Kogel AJ, Sayre JW, McBride WH, Solberg TD. Spinal cord tolerance to single-fraction partial-volume irradiation: a swine model. Int J Radiat Oncol Biol Phys 2010; 79:226-32. [PMID: 20934278 DOI: 10.1016/j.ijrobp.2010.07.1979] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 07/21/2010] [Accepted: 07/22/2010] [Indexed: 11/30/2022]
Abstract
PURPOSE To determine the spinal cord tolerance to single-fraction, partial-volume irradiation in swine. METHODS AND MATERIALS A 5-cm-long cervical segment was irradiated in 38-47-week-old Yucatan minipigs using a dedicated, image-guided radiosurgery linear accelerator. The radiation was delivered to a cylindrical volume approximately 5 cm in length and 2 cm in diameter that was positioned lateral to the cervical spinal cord, resulting in a dose distribution with the 90%, 50%, and 10% isodose lines traversing the ipsilateral, central, and contralateral spinal cord, respectively. The dose was prescribed to the 90% isodose line. A total of 26 pigs were stratified into eight dose groups of 12-47 Gy. The mean maximum spinal cord dose was 16.9 ± 0.1, 18.9 ± 0.1, 21.0 ± 0.1, 23.0 ± 0.2, and 25.3 ± 0.3 Gy in the 16-, 18-, 20-, 22-, and 24-Gy dose groups, respectively. The mean percentage of spinal cord volumes receiving ≥ 10 Gy for the same groups were 43% ± 3%, 48% ± 4%, 51% ± 2%, 57% ± 2%, and 59% ± 4%. The study endpoint was motor neurologic deficit determined by a change in gait during a 1-year follow-up period. RESULTS A steep dose-response curve was observed with a median effective dose for the maximum dose point of 20.0 Gy (95% confidence interval, 18.3-21.7). Excellent agreement was observed between the occurrence of neurologic change and the presence of histologic change. All the minipigs with motor deficits showed some degree of demyelination and focal white matter necrosis on the irradiated side, with relative sparing of the gray matter. The histologic findings were unremarkable in the minipigs with normal neurologic status. CONCLUSIONS Our results have indicated that for a dose distribution with a steep lateral gradient, the pigs had a lower median effective dose for paralysis than has been observed in rats and more closely resembles that for rats, mice, and guinea pigs receiving uniform spinal cord irradiation.
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Affiliation(s)
- Paul M Medin
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9183, USA.
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Sahgal A, Ma L, Gibbs I, Gerszten PC, Ryu S, Soltys S, Weinberg V, Wong S, Chang E, Fowler J, Larson DA. Spinal Cord Tolerance for Stereotactic Body Radiotherapy. Int J Radiat Oncol Biol Phys 2010; 77:548-53. [PMID: 19765914 DOI: 10.1016/j.ijrobp.2009.05.023] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 05/14/2009] [Accepted: 05/19/2009] [Indexed: 11/28/2022]
Affiliation(s)
- Arjun Sahgal
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, Canada.
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Kirkpatrick JP, van der Kogel AJ, Schultheiss TE. Radiation Dose–Volume Effects in the Spinal Cord. Int J Radiat Oncol Biol Phys 2010; 76:S42-9. [PMID: 20171517 DOI: 10.1016/j.ijrobp.2009.04.095] [Citation(s) in RCA: 322] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 04/17/2009] [Accepted: 04/22/2009] [Indexed: 12/22/2022]
Affiliation(s)
- John P Kirkpatrick
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA.
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40
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Kuijper IT, Dahele M, Senan S, Verbakel WF. Volumetric modulated arc therapy versus conventional intensity modulated radiation therapy for stereotactic spine radiotherapy: A planning study and early clinical data. Radiother Oncol 2010; 94:224-8. [DOI: 10.1016/j.radonc.2009.12.027] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 12/22/2009] [Accepted: 12/22/2009] [Indexed: 11/16/2022]
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Tumeurs spinales et paraspinales traitées par irradiation stéréotaxique par CyberKnife® au centre Antoine-Lacassagne de Nice. Cancer Radiother 2010; 14:5-10. [DOI: 10.1016/j.canrad.2009.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 09/21/2009] [Accepted: 09/24/2009] [Indexed: 11/20/2022]
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van Luijk P, Faber H, Schippers JM, Brandenburg S, Langendijk JA, Meertens H, Coppes RP. Bath and shower effects in the rat parotid gland explain increased relative risk of parotid gland dysfunction after intensity-modulated radiotherapy. Int J Radiat Oncol Biol Phys 2009; 74:1002-5. [PMID: 19545785 DOI: 10.1016/j.ijrobp.2009.03.039] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 03/13/2009] [Accepted: 03/15/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE To assess in a rat model whether adding a subtolerance dose in a region adjacent to a high-dose irradiated subvolume of the parotid gland influences its response (bath-and-shower effect). METHODS AND MATERIALS Irradiation of the whole, cranial 50%, and/or the caudal 50% of the parotid glands of Wistar rats was performed using 150-MeV protons. To determine suitable (i.e., subtolerance) dose levels for a bath-dose, both whole parotid glands were irradiated with 5 to 25 Gy. Subsequently groups of Wistar rats received 30 Gy to the caudal 50% (shower) and 0 to 10 Gy to the cranial 50% (bath) of both parotid glands. Stimulated saliva flow rate (function) was measured before and up to 240 days after irradiation. RESULTS Irradiation of both glands up to a dose of 10 Gy did not result in late loss of function and is thus regarded subtolerance. Addition of a dose bath of 1 to 10 Gy to a high-dose in the caudal 50% of the glands resulted in enhanced function loss. CONCLUSION Similar to the spinal cord, the parotid gland demonstrates a bath and shower effect, which may explain the less-than-expected sparing of function after IMRT.
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Affiliation(s)
- Peter van Luijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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Adamus-Górka M, Brahme A, Mavroidis P, Lind BK. Variation in radiation sensitivity and repair kinetics in different parts of the spinal cord. Acta Oncol 2009; 47:928-36. [PMID: 18568487 DOI: 10.1080/02841860701864668] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND The spinal cord, known for its strongly serial character and high sensitivity to radiation even when a small segment is irradiated, is one of the most critical organs at risk to be spared during radiation therapy. To compare the sensitivity of different parts of the spinal cord, data for radiation myelopathy have been used. MATERIAL AND METHODS In the present study, the relative seriality model was fitted to two different datasets of clinical radiation myelitis concerning cervical spinal cord after treating 248 patients for head and neck cancer and thoracic spinal cord after treating 43 patients with lung carcinoma. The maximum likelihood method was applied to fit the clinical data. The model parameters and their 68% confidence intervals were calculated for each dataset. The alpha/beta ratio for the thoracic cord was also was also found to be 0.9 (0-3.0) Gy. RESULTS The dose-response curve for the more sensitive cervical myelopathy is well described by the parameters D(50)=55.9 (54.8-57.1) Gy, gamma=6.9 (5.0-9.2), s=0.13 (0.07-0.24), whereas the thoracic myelopathy is described by the parameters D(50)=75.5 (70.5-80.8) Gy, gamma=1.1 (0.6-1.6), s=36 (3.3-infinity). DISCUSSION AND CONCLUSIONS Large differences in radiation response between the cervical and thoracic region of spinal cord are thus observed: cervical myelopathy seems to be characterized by medium seriality, while thoracic spinal cord is characterized by a highly serial dose-response. The much steeper dose-response curve for cervical spinal cord myelopathy can be interpreted as a higher number of functional subunits consistent with a higher amount of white matter close to the brain.
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Philippens MEP, Gambarota G, van der Kogel AJ, Heerschap A. Radiation Effects in the Rat Spinal Cord: Evaluation with Apparent Diffusion Coefficient versus T2 at Serial MR Imaging. Radiology 2009; 250:387-97. [DOI: 10.1148/radiol.2502071374] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Nguyen TB, Hoole ACF, Burnet NG, Thomas SJ. Dose–volume population histogram: a new tool for evaluating plans whilst considering geometrical uncertainties. Phys Med Biol 2009; 54:935-47. [DOI: 10.1088/0031-9155/54/4/008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Nelson JW, Yoo DS, Sampson JH, Isaacs RE, Larrier NA, Marks LB, Yin FF, Wu QJ, Wang Z, Kirkpatrick JP. Stereotactic body radiotherapy for lesions of the spine and paraspinal regions. Int J Radiat Oncol Biol Phys 2008; 73:1369-75. [PMID: 19004569 DOI: 10.1016/j.ijrobp.2008.06.1949] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 06/13/2008] [Accepted: 06/20/2008] [Indexed: 02/08/2023]
Abstract
PURPOSE To describe our experience and clinical strategy for stereotactic body radiotherapy (SBRT) of spinal lesions. METHODS AND MATERIALS Thirty-two patients with 33 spinal lesions underwent computed tomography-based simulation while free breathing. Gross/clinical target volumes included involved portions of the vertebral body and paravertebral/epidural tumor. Planning target volume (PTV) expansion was 6 mm axially and 3 mm radially; the cord was excluded from the PTV. Biologic equivalent dose was calculated using the linear quadratic model with alpha/beta = 3 Gy. Treatment was linear accelerator based with on-board imaging; dose was adjusted to maintain cord dose within tolerance. Survival, local control, pain, and neurologic status were monitored. RESULTS Twenty-one patients are alive at 1 year (median survival, 14 months). Median follow-up is 6 months for all patients (7 months for survivors). Mean previous radiotherapy dose to 22 patients was 35 Gy, and median interval was 17 months. Renal (31%), breast, and lung (19% each) were the most common histologic sites. Three SBRT fractions (range, one to four fractions) of 7 Gy (range, 5-16 Gy) were delivered. Median cord and target biologic equivalent doses were 70 Gy(3) and 34.3 Gy(10), respectively. Thirteen patients reported complete and 17 patients reported partial pain relief at 1 month. There were four failures (mean, 5.8 months) with magnetic resonance imaging evidence of in-field progression. No dosimetric parameters predictive of failure were identified. No treatment-related toxicity was seen. CONCLUSIONS Spinal SBRT is effective in the palliative/re-treatment setting. Volume expansion must ensure optimal PTV coverage while avoiding spinal cord toxicity. The long-term safety of spinal SBRT and the applicability of the linear-quadratic model in this setting remain to be determined, particularly the time-adjusted impact of prior radiotherapy.
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Affiliation(s)
- John W Nelson
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
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Adamus-Górka M, Mavroidis P, Brahme A, Lind BK. The dose–response relation for rat spinal cord paralysis analyzed in terms of the effective size of the functional subunit. Phys Med Biol 2008; 53:6533-47. [DOI: 10.1088/0031-9155/53/22/016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Kavanagh B. Clinical Experience Shows That Catastrophic Late Effects Associated With Ablative Fractionation Can Be Avoided by Technological Innovation. Semin Radiat Oncol 2008; 18:223-8. [DOI: 10.1016/j.semradonc.2008.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Philippens MEP, Pop LAM, Visser AG, van der Kogel AJ. Dose-volume effects in rat thoracolumbar spinal cord: the effects of nonuniform dose distribution. Int J Radiat Oncol Biol Phys 2007; 69:204-13. [PMID: 17707274 DOI: 10.1016/j.ijrobp.2007.05.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2007] [Revised: 05/12/2007] [Accepted: 05/14/2007] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate dose-volume effects in rat spinal cord irradiated with nonuniform dose distributions and to assess regional differences in radiosensitivity. METHODS AND MATERIALS A total of 106 rats divided into three groups were irradiated with (192)Ir gamma-rays at a high dose rate. The groups were irradiated with one, two, or six catheters distributed around the thoracolumbar spinal cord to create different dose distributions. After irradiation, the animals were tested for motor function for 9 months. The response was defined as motor dysfunction and WM or nerve root necrosis. Dose-response data were analyzed with a probit analysis as function of the dose level at a percentage of the volume (D(%)) and with different normal tissue complication probability models. Additionally, the histologic responses of the individual dose voxels were analyzed after registration with the histologic sections. RESULTS The probit analysis at D(24) (24% of the volume) gave the best fit results. In addition, the Lyman Kutcher Burman model and the relative seriality model showed acceptable fits, with volume parameters of 0.17 and 0.53, respectively. The histology-based analysis revealed a lower radiosensitivity for the dorsal (50% isoeffective dose [ED(50)] = 32.3) and lateral WM (ED(50) = 33.7 Gy) compared with the dorsal (ED(50) = 25.9 Gy) and ventral nerve roots (ED(50) = 24.1 Gy). CONCLUSIONS For this nonuniform irradiation, the spinal cord did not show typical serial behavior. No migration terms were needed for an acceptable fit of the dose-response curves. A higher radiosensitivity for the lumbar nerve roots than for the thoracic WM was found.
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Affiliation(s)
- Mariëlle E P Philippens
- Department of Radiation Oncology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
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Qiu D, Kwong DLW, Chan GCF, Leung LHT, Khong PL. Diffusion tensor magnetic resonance imaging finding of discrepant fractional anisotropy between the frontal and parietal lobes after whole-brain irradiation in childhood medulloblastoma survivors: reflection of regional white matter radiosensitivity? Int J Radiat Oncol Biol Phys 2007; 69:846-51. [PMID: 17544593 DOI: 10.1016/j.ijrobp.2007.04.041] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 04/13/2007] [Accepted: 04/13/2007] [Indexed: 11/30/2022]
Abstract
PURPOSE To test the hypothesis that fractional anisotropy (FA) is more severely reduced in white matter of the frontal lobe compared with the parietal lobe after receiving the same whole-brain irradiation dose in a cohort of childhood medulloblastoma survivors. METHODS AND MATERIALS Twenty-two medulloblastoma survivors (15 male, mean [+/- SD] age = 12.1 +/- 4.6 years) and the same number of control subjects (15 male, aged 12.0 +/- 4.2 years) were recruited for diffusion tensor magnetic resonance imaging scans. Using an automated tissue classification method and the Talairach Daemon atlas, FA values of frontal and parietal lobes receiving the same radiation dose, and the ratio between them were quantified and denoted as FFA, PFA, and FA(f/p), respectively. The Mann-Whitney U test was used to test for significant differences of FFA, PFA, and FA(f/p) between medulloblastoma survivors and control subjects. RESULTS Frontal lobe and parietal lobe white matter FA were found to be significantly less in medulloblastoma survivors compared with control subjects (frontal p = 0.001, parietal p = 0.026). Moreover, these differences were found to be discrepant, with the frontal lobe having a significantly larger difference in FA compared with the parietal lobe. The FA(f/p) of control and medulloblastoma survivors was 1.110 and 1.082, respectively (p = 0.029). CONCLUSION Discrepant FA changes after the same irradiation dose suggest radiosensitivity of the frontal lobe white matter compared with the parietal lobe. Special efforts to address the potentially vulnerable frontal lobe after treatment with whole-brain radiation may be needed so as to balance disease control and treatment-related morbidity.
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Affiliation(s)
- Deqiang Qiu
- Department of Diagnostic Radiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong
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