1
|
Piperno G, Ferrari A, Volpe S, Cattani F, Zaffaroni M, Comi S, Pansini F, Bergamaschi L, Mazzola GC, Ceci F, Colandrea M, Petralia G, Orecchia R, Jereczek-Fossa BA, Alterio D. Hypofractionated proton therapy for benign tumors of the central nervous system: A systematic review of the literature. Crit Rev Oncol Hematol 2023; 191:104114. [PMID: 37683814 DOI: 10.1016/j.critrevonc.2023.104114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/26/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
AIMS Aim of the present analysis was to report results of a systematic review of the literature in the setting of patients treated with hypoF PT for benign lesions of the central nervous system (CNS). METHODS The methodology complied with the PRISMA recommendations. PubMed, EMBASE and Scopus databases were interrogated in September 2022. RESULTS Twelve papers have been selected including patients treated for base of the skull meningiomas (6 papers), vestibular schwannoma (3 papers) and pituitary adenomas (3 papers). Clinical outcomes were evaluated with both radiologic images and clinical parameters. Long-term toxicity was reported in all but one series with an incidence ranging from 2 % to 7 % in patients treated for base of skull meningioma and 1-9 % for schwannoma. CONCLUSIONS HypoF PT is a safe and effective treatment in selected benign tumors of the CNS. Further dosimetric and clinical comparisons are required to better refine the patients' selection criteria.
Collapse
Affiliation(s)
- Gaia Piperno
- Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Annamaria Ferrari
- Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Stefania Volpe
- Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy.
| | - Federica Cattani
- Unit of Medical Physics, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Mattia Zaffaroni
- Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Stefania Comi
- Unit of Medical Physics, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Floriana Pansini
- Unit of Medical Physics, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Luca Bergamaschi
- Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy
| | | | - Francesco Ceci
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy; Division of Nuclear Medicine, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Marzia Colandrea
- Precision Imaging and Research Unit, Department of Medical Imaging and Radiation Sciences, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Giuseppe Petralia
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy; Precision Imaging and Research Unit, Department of Medical Imaging and Radiation Sciences, IEO European Institute of Oncology IRCCS, Milan, Italy
| | - Roberto Orecchia
- Scientific Directorate, IEO European Institute of Oncology, IRCCS, Milan, Italy
| | - Barbara Alicja Jereczek-Fossa
- Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Daniela Alterio
- Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy
| |
Collapse
|
2
|
Saraf A, Pike LRG, Franck KH, Horick NK, Yeap BY, Fullerton BC, Wang IS, Abazeed ME, McKenna MJ, Mehan WA, Plotkin SR, Loeffler JS, Shih HA. Fractionated Proton Radiation Therapy and Hearing Preservation for Vestibular Schwannoma: Preliminary Analysis of a Prospective Phase 2 Clinical Trial. Neurosurgery 2022; 90:506-514. [PMID: 35229827 PMCID: PMC9514734 DOI: 10.1227/neu.0000000000001869] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/03/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Local management for vestibular schwannoma (VS) is associated with excellent local control with focus on preserving long-term serviceable hearing. Fractionated proton radiation therapy (FPRT) may be associated with greater hearing preservation because of unique dosimetric properties of proton radiotherapy. OBJECTIVE To investigate hearing preservation rates of FPRT in adults with VS and secondarily assess local control and treatment-related toxicity. METHODS A prospective, single-arm, phase 2 clinical trial was conducted of patients with VS from 2010 to 2019. All patients had serviceable hearing at baseline and received FPRT to a total dose of 50.4 to 54 Gy relative biological effectiveness (RBE) over 28 to 30 fractions. Serviceable hearing preservation was defined as a Gardner-Robertson score of 1 to 2, measured by a pure tone average (PTA) of ≤50 dB and a word recognition score (WRS) of ≥50%. RESULTS Twenty patients had a median follow-up of 4.0 years (range 1.0-5.0 years). Local control at 4 years was 100%. Serviceable hearing preservation at 1 year was 53% (95% CI 29%-76%), and primary end point was not yet reached. Median PTA and median WRS both worsened 1 year after FPRT (P < .0001). WRS plateaued after 6 months, whereas PTA continued to worsen up to 1 year after FPRT. Median cochlea D90 was lower in patients with serviceable hearing at 1 year (40.6 Gy [RBE] vs 46.9 Gy [RBE]), trending toward Wilcoxon rank-sum test statistical significance (P = .0863). Treatment was well-tolerated, with one grade 1 cranial nerve V dysfunction and no grade 2+ cranial nerve dysfunction. CONCLUSION FPRT for VS did not meet the goal of serviceable hearing preservation. Higher cochlea doses trended to worsening hearing preservation, suggesting that dose to cochlea correlates with hearing preservation independent of treatment modality.
Collapse
Affiliation(s)
- Anurag Saraf
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA;
- Harvard Radiation Oncology Program, Boston, Massachusetts, USA;
| | - Luke R. G. Pike
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA;
- Harvard Radiation Oncology Program, Boston, Massachusetts, USA;
- Memorial Sloan Kettering Cancer Center, New York, New York, USA;
| | - Kevin H. Franck
- Department of Otolaryngology–Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA;
| | - Nora K. Horick
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA;
| | - Beow Y. Yeap
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA;
| | - Barbara C. Fullerton
- Department of Otolaryngology–Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA;
| | - Irene S. Wang
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA;
| | - Mohamed E. Abazeed
- Department of Radiation Oncology, Northwestern University, Chicago, Illinois, USA;
| | - Michael J. McKenna
- Department of Otolaryngology–Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA;
| | - William A. Mehan
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA;
| | - Scott R. Plotkin
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jay S. Loeffler
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA;
| | - Helen A. Shih
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA;
| |
Collapse
|
3
|
Li Y, Li X, Yang J, Wang S, Tang M, Xia J, Gao Y. Flourish of Proton and Carbon Ion Radiotherapy in China. Front Oncol 2022; 12:819905. [PMID: 35237518 PMCID: PMC8882681 DOI: 10.3389/fonc.2022.819905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/24/2022] [Indexed: 11/13/2022] Open
Abstract
Proton and heavy ion therapy offer superior relative biological effectiveness (RBE) in the treatment of deep-seated tumors compared with conventional photon radiotherapy due to its Bragg-peak feature of energy deposition in organs. Many proton and carbon ion therapy centers are active all over the world. At present, five particle radiotherapy institutes have been built and are receiving patient in China, mainly including Wanjie Proton Therapy Center (WPTC), Shanghai Proton Heavy Ion Center (SPHIC), Heavy Ion Cancer Treatment Center (HIMM), Chang Gung Memorial Hospital (CGMH), and Ruijin Hospital affiliated with Jiao Tong University. Many cancer patients have benefited from ion therapy, showing unique advantages over surgery and chemotherapy. By the end of 2020, nearly 8,000 patients had been treated with proton, carbon ion or carbon ion combined with proton therapy. So far, there is no systemic review for proton and carbon ion therapy facility and clinical outcome in China. We reviewed the development of proton and heavy ion therapy, as well as providing the representative clinical data and future directions for particle therapy in China. It has important guiding significance for the design and construction of new particle therapy center and patients’ choice of treatment equipment.
Collapse
Affiliation(s)
- Yue Li
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- *Correspondence: Yue Li,
| | - Xiaoman Li
- Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Jiancheng Yang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
| | - Sicheng Wang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
| | - Meitang Tang
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
| | - Jiawen Xia
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- Huizhou Research Center of Ion Science, Chinese Academy of Sciences, Huizhou, China
| | - Yunzhe Gao
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
4
|
Zhang Q, Kong L, Liu R, Wang X. Ion therapy guideline (Version 2020). PRECISION RADIATION ONCOLOGY 2021. [DOI: 10.1002/pro6.1120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Qiuning Zhang
- Institute of Modern Physics, Chinese Academy of Sciences & Lanzhou Heavy Ion Hospital, ••• No.509 Nanchang road, Chengguan district, Lanzhou city Lanzhou City 730000 China
| | - Lin Kong
- Shanghai Proton Heavy Ion Hospital, Shanghai China
| | - Ruifeng Liu
- Institute of Modern Physics, Chinese Academy of Sciences & Lanzhou Heavy Ion Hospital, ••• No.509 Nanchang road, Chengguan district, Lanzhou city Lanzhou City 730000 China
| | - Xiaohu Wang
- Institute of Modern Physics, Chinese Academy of Sciences & Lanzhou Heavy Ion Hospital, ••• No.509 Nanchang road, Chengguan district, Lanzhou city Lanzhou City 730000 China
| |
Collapse
|
5
|
Constanzo J, Vanstalle M, Finck C, Brasse D, Rousseau M. Dosimetry and characterization of a 25-MeV proton beam line for preclinical radiobiology research. Med Phys 2019; 46:2356-2362. [PMID: 30924942 DOI: 10.1002/mp.13512] [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: 11/05/2018] [Revised: 02/26/2019] [Accepted: 03/21/2019] [Indexed: 11/12/2022] Open
Abstract
PURPOSE With the increase in proton therapy centers, there is a growing need to make progress in preclinical proton radiation biology to give accessible data to medical physicists and practicing radiation oncologists. METHODS A cyclotron usually producing radioisotopes with a proton beam at an energy of about 25 MeV after acceleration, was used for radiobiology studies. Depleted silicon surface barrier detectors were used for the beam energy measurement. A complementary metal oxide semiconductor (CMOS) sensor and a plastic scintillator detector were used for fluence measurement, and compared to Geant4 and an in-house analytical dose modeling developed for this purpose. Also, from the energy measurement of each attenuated beam, the dose-averaged linear energy transfer (LETd ) was calculated with Geant4. RESULTS The measured proton beam energy was 24.85 ± 0.14 MeV with an energy straggling of 127 ± 22 keV before scattering and extraction in air. The measured flatness was within ± 2.1% over 9 mm in diameter. A wide range of LETd is achievable: constant between the entrance and the exit of the cancer cell sample ranging from 2.2 to 8 keV/μm, beyond 20 keV/μm, and an average of 2-5 keV/μm in a scattering spread-out Bragg peak calculated for an example of a 6-mm-thick xenograft tumor. CONCLUSION The dosimetry and the characterization of a 25-MeV proton beam line for preclinical radiobiology research was performed by measurements and modeling, demonstrating the feasibility of delivering a proton beam for preclinical in vivo and in vitro studies with LETd of clinical interest.
Collapse
Affiliation(s)
- Julie Constanzo
- Université de Strasbourg, CNRS, IPHC, UMR 7178, F-67000, Strasbourg, France
| | - Marie Vanstalle
- Université de Strasbourg, CNRS, IPHC, UMR 7178, F-67000, Strasbourg, France
| | - Christian Finck
- Université de Strasbourg, CNRS, IPHC, UMR 7178, F-67000, Strasbourg, France
| | - David Brasse
- Université de Strasbourg, CNRS, IPHC, UMR 7178, F-67000, Strasbourg, France
| | - Marc Rousseau
- Université de Strasbourg, CNRS, IPHC, UMR 7178, F-67000, Strasbourg, France
| |
Collapse
|
6
|
El Shafie RA, Czech M, Kessel KA, Habermehl D, Weber D, Rieken S, Bougatf N, Jäkel O, Debus J, Combs SE. Clinical outcome after particle therapy for meningiomas of the skull base: toxicity and local control in patients treated with active rasterscanning. Radiat Oncol 2018; 13:54. [PMID: 29587795 PMCID: PMC5870393 DOI: 10.1186/s13014-018-1002-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 03/16/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Meningiomas of the skull base account for 25-30% of all meningiomas. Due to the complex structure of the cranial base and its close proximity to critical structures, surgery is often associated with substantial morbidity. Treatment options include observation, aggressive surgical intervention, stereotactic or conventional radiotherapy. In this analysis we evaluate the outcome of 110 patients with meningiomas of the skull base treated with particle therapy. It was performed within the framework of the "clinical research group heavy ion therapy" and supported by the German Research Council (DFG, KFO 214). METHODS Between May 2010 and November 2014, 110 Patients with skull base meningioma were treated with particle radiotherapy at the Heidelberg Ion Therapy Center (HIT). Primary localizations included the sphenoid wing (n = 42), petroclival region (n = 23), cavernous sinus (n = 4), sella (n = 10) and olfactory nerve (n = 4). Sixty meningiomas were benign (WHO °I); whereas 8 were high-risk (WHO °II (n = 7) and °III (n = 1)). In 42 cases histology was not examined, since no surgery was performed. Proton (n = 104) or carbon ion (n = 6) radiotherapy was applied at Heidelberg Ion Therapy Center (HIT) using raster-scanning technique for active beam delivery. Fifty one patients (46.4%) received radiotherapy due to tumor progression, 17 (15.5%) after surgical resection and 42 (38.2%) as primary treatment. RESULTS Median follow-up in this analysis was 46,8 months (95% CI 39,9-53,7; Q1-Q3 34,3-61,7). Particle radiotherapy could be performed safely without toxicity-related interruptions. No grade IV or V toxicities according to CTCAE v4.0 were observed. Particle RT offered excellent overall local control rates with 100% progression-free survival (PFS) after 36 months and 96.6% after 60 months. Median PFS was not reached due to the small number of events. Histology significantly impacted PFS with superior PFS after 5 years for low-risk tumors (96.6% vs. 75.0%, p = 0,02). Overall survival was 96.2% after 60 months and 92.0% after 72 months from therapy. Of six documented deaths, five were definitely not and the sixth probably not meningioma-related. CONCLUSION Particle radiotherapy is an excellent treatment option for patients with meningiomas of the skull base and can lead to long-term tumor control with minimal side effects. Other prospective studies with longer follow-up will be necessary to further confirm the role of particle radiotherapy in skull base meningioma.
Collapse
Affiliation(s)
- Rami A El Shafie
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. .,Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
| | - Maja Czech
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Kerstin A Kessel
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München (TUM), Ismaninger Straße 22, 81675, Munich, Germany.,Helmholtz Zentrum München, Department of Radiation Sciences (DRS), Institute of Innovative Radiotherapy (iRT), Ingolstädter Landstraße 1, Munich, Germany.,Deutsches Konsortium für Translationale Krebsforschung (DKTK), Partner Site Munich, Munich, Germany
| | - Daniel Habermehl
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München (TUM), Ismaninger Straße 22, 81675, Munich, Germany.,Helmholtz Zentrum München, Department of Radiation Sciences (DRS), Institute of Innovative Radiotherapy (iRT), Ingolstädter Landstraße 1, Munich, Germany.,Deutsches Konsortium für Translationale Krebsforschung (DKTK), Partner Site Munich, Munich, Germany
| | - Dorothea Weber
- Institute for Medical Biometry and Informatics (IMBI), Heidelberg University Hospital, Im Neuenheimer Feld 130.3, 69120, Heidelberg, Germany
| | - Stefan Rieken
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion Therapy Center (HIT), Im Neuenheimer Feld 470, 69120, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Nina Bougatf
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion Therapy Center (HIT), Im Neuenheimer Feld 470, 69120, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Oliver Jäkel
- Deutsches Krebsforschungszentrum (dkfz), Abteilung Medizinphysik, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,Heidelberg Ion Therapy Center (HIT), Im Neuenheimer Feld 470, 69120, Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion Therapy Center (HIT), Im Neuenheimer Feld 470, 69120, Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology (E050), German Cancer Research Center (dkfz), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Stephanie E Combs
- Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München (TUM), Ismaninger Straße 22, 81675, Munich, Germany.,Helmholtz Zentrum München, Department of Radiation Sciences (DRS), Institute of Innovative Radiotherapy (iRT), Ingolstädter Landstraße 1, Munich, Germany.,Deutsches Konsortium für Translationale Krebsforschung (DKTK), Partner Site Munich, Munich, Germany
| |
Collapse
|
7
|
Keawsamur M, Matsumura A, Souda H, Kano Y, Torikoshi M, Nakano T, Kanai T. Development of stereotactic radiosurgery using carbon beams (carbon-knife). ACTA ACUST UNITED AC 2018; 63:045024. [DOI: 10.1088/1361-6560/aaaa4d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
8
|
Slater JD. Clinical Applications of Proton Radiation Treatment at Loma Linda University: Review of a Fifteen-year Experience. Technol Cancer Res Treat 2016; 5:81-9. [PMID: 16551128 DOI: 10.1177/153303460600500202] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Proton radiation therapy has been used at Loma Linda University Medical Center for 15 years, sometimes in combination with photon irradiation, surgery, and chemotherapy, but often as the sole modality. Our initial experience was based on established studies showing the utility of protons for certain management problems, but since then we have engaged in a planned program to exploit the capabilities of proton radiation and expand its applications in accordance with progressively accumulating clinical data. Our cumulative experience has confirmed that protons are a superb tool for delivering conformal radiation treatments, enabling delivery of effective doses of radiation and sparing normal tissues from radiation exposure.
Collapse
Affiliation(s)
- Jerry D Slater
- Department of Radiation Medicine, Loma Linda University, 11234 Anderson Street, Loma Linda, CA 92354, USA.
| |
Collapse
|
9
|
Vernimmen F. Intracranial Stereotactic Radiation Therapy With Charged Particle Beams: An Opportunity to Regain the Momentum. Int J Radiat Oncol Biol Phys 2016; 95:52-55. [DOI: 10.1016/j.ijrobp.2015.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/03/2015] [Accepted: 10/06/2015] [Indexed: 11/16/2022]
|
10
|
Abstract
ABSTRACT:The term radiosurgery has been used to describe a variety of radiotherapy techniques which deliver high doses of radiation to small, stereotactically defined intracranial targets in such a way that the dose fall-off outside the targeted volume is very sharp. Proton, charged particle, gamma unit, and linear accelerator-based techniques appear to be equivalent from the standpoint of accuracy, dose distributions, and clinical results. However, capital and operating costs associated with the use of linear accelerators in general clinical use are much lower. Radiosurgery has an established role in the treatment of arteriovenous malformations and acoustic neurinomas. Interest in these techniques is increasing in neurosurgical and radiation oncological communities, as radiosurgery is rapidly assuming a place in the management of several other conditions, including craniopharyngiomas, meningiomas, and selected malignant lesions.
Collapse
|
11
|
Amichetti M, Amelio D, Minniti G. Radiosurgery with photons or protons for benign and malignant tumours of the skull base: a review. Radiat Oncol 2012; 7:210. [PMID: 23241206 PMCID: PMC3552759 DOI: 10.1186/1748-717x-7-210] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 12/12/2012] [Indexed: 01/25/2023] Open
Abstract
Stereotactic radiosurgery (SRS) is an important treatment option for intracranial lesions. Many studies have shown the effectiveness of photon-SRS for the treatment of skull base (SB) tumours; however, limited data are available for proton-SRS.Several photon-SRS techniques, including Gamma Knife, modified linear accelerators (Linac) and CyberKnife, have been developed and several studies have compared treatment plan characteristics between protons and photons.The principles of classical radiobiology are similar for protons and photons even though they differ in terms of physical properties and interaction with matter resulting in different dose distributions.Protons have special characteristics that allow normal tissues to be spared better than with the use of photons, although their potential clinical superiority remains to be demonstrated.A critical analysis of the fundamental radiobiological principles, dosimetric characteristics, clinical results, and toxicity of proton- and photon-SRS for SB tumours is provided and discussed with an attempt of defining the advantages and limits of each radiosurgical technique.
Collapse
Affiliation(s)
- Maurizio Amichetti
- ATreP, Provincial Agency for Proton Therapy, via Perini 181, Trento 38122, Italy.
| | | | | |
Collapse
|
12
|
Andisheh B, Brahme A, Bitaraf MA, Mavroidis P, Lind BK. Clinical and radiobiological advantages of single-dose stereotactic light-ion radiation therapy for large intracranial arteriovenous malformations. Technical note. J Neurosurg 2009; 111:919-26. [PMID: 19392591 DOI: 10.3171/2007.10.17205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Radiation treatment of large arteriovenous malformations (AVMs) remains difficult and not very effective, even though seemingly promising methods such as staged volume treatments have been proposed by some radiation treatment centers. In symptomatic patients harboring large intracranial AVMs not amenable to embolization or resection, single-session high-dose stereotactic radiation therapy is a viable option, and the special characteristics of high-ionization-density light-ion beams offer several treatment advantages over photon and proton beams. These advantages include a more favorable depth-dose distribution in tissue, an almost negligible lateral scatter of the beam, a sharper penumbra, a steep dose falloff beyond the Bragg peak, and a higher probability of vascular response due to high ionization density and associated induction of endothelial cell proliferation and/or apoptosis. Carbon ions were recently shown to be an effective treatment for skull-base tumors. Bearing that in mind, the authors postulate that the unique physical and biological characteristics of light-ion beams should convey considerable clinical advantages in the treatment of large AVMs. In the present meta-analysis the authors present a comparison between light-ion beam therapy and more conventional modalities of radiation treatment with respect to these lesions. METHODS Dose-volume histograms and data on peripheral radiation doses for treatment of large AVMs were collected from various radiation treatment centers. Dose-response parameters were then derived by applying a maximum likelihood fitting of a binomial model to these data. The present binomial model was needed because the effective number of crucial blood vessels in AVMs (the number of vessels that must be obliterated to effect a cure, such as large fistulous nidus vessels) is low, making the Poisson model less suitable. In this study the authors also focused on radiobiological differences between various radiation treatments. RESULTS Light-ion Bragg-peak dose delivery has the precision required for treating very large AVMs as well as for delivering extremely sharp, focused beams to irregular lesions. Stereotactic light-ion radiosurgery resulted in better angiographically defined obliteration rates, less white-matter necrosis, lower complication rates, and more favorable clinical outcomes. In addition, in patients treated by He ion beams, a sharper dose-response gradient was observed, probably due to a more homogeneous radiosensitivity of the AVM nidus to light-ion beam radiation than that seen when low-ionization-density radiation modalities, such as photons and protons, are used. CONCLUSIONS Bragg-peak radiosurgery can be recommended for most large and irregular AVMs and for the treatment of lesions located in front of or adjacent to sensitive and functionally important brain structures. The unique physical and biological characteristics of light-ion beams are of considerable advantage for the treatment of AVMs: the densely ionizing beams of light ions create a better dose and biological effect distribution than conventional radiation modalities such as photons and protons. Using light ions, greater flexibility can be achieved while avoiding healthy critical structures such as diencephalic and brainstem nuclei and tracts. Treatment with the light ion He or Li is more suitable for AVMs <or= 10 cm(3), whereas treatment with the light ion Li, Be, or C may be more appropriate for larger AVMs. A binomial model based on the effective number of crucial vessels in the AVM may be used quite well to predict AVM obliteration probabilities for both small and large AVMs when therapies involving either photons or light ions are used.
Collapse
Affiliation(s)
- Bahram Andisheh
- Department of Medical Radiation Physics, Karolinska Institute and Stockholm University, Stockholm, Sweden.
| | | | | | | | | |
Collapse
|
13
|
Vernimmen FJAI, Mohamed Z, Slabbert JP, Wilson J. Long-term results of stereotactic proton beam radiotherapy for acoustic neuromas. Radiother Oncol 2008; 90:208-12. [PMID: 19054586 DOI: 10.1016/j.radonc.2008.11.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Revised: 10/27/2008] [Accepted: 11/07/2008] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE A retrospective study evaluating the role of hypofractionated stereotactic proton beam therapy for acoustic neuromas. MATERIALS AND METHODS The data of 51 patients treated with hypofractionation (3 fractions) and followed up for a minimum of 2 years, were analyzed. Mean dose prescribed to ICRU reference point (isocenter) was 26 cobalt gray equivalent (CGyE) in 3 fractions. Mean minimum tumor dose was 21.4 CGyE/3. Cranial nerve functions were evaluated clinically. Serial MR Scans were used to evaluate local control. RESULTS With a mean clinical and radiological follow-up of 72 and 60 months respectively, the 5-year results showed a 98% local control, with a hearing preservation of 42%, a facial nerve preservation of 90.5% and a trigeminal nerve preservation of 93%. CONCLUSION For those patients harboring large acoustic neuromas that are inoperable, hypofractionated stereotactic proton beam offers long-term control with minimal side-effects.
Collapse
|
14
|
Amirul Islam M, Yanagi T, Mizoe JE, Mizuno H, Tsujii H. Comparative study of dose distribution between carbon ion radiotherapy and photon radiotherapy for head and neck tumor. ACTA ACUST UNITED AC 2008; 26:415-21. [PMID: 18769999 DOI: 10.1007/s11604-008-0252-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Accepted: 04/14/2008] [Indexed: 11/27/2022]
Abstract
PURPOSE A comparative treatment planning study has been performed between carbon ion radiotherapy (CIRT) and photon radiotherapy [three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)] to assess the potential improvements and limitations that could result for locally advanced, nonresectable head and neck tumors. MATERIALS AND METHODS Seven patients, originally treated with CIRT, were randomly selected for the comparative study. The evaluations analyzed using dose-volume histogram parameters, conformity index, inhomogeneity coefficient, and dose to the organs at risk (OARs). RESULTS The mean conformity index was 1.46, 1.43, and 1.22 for 3D-CRT, IMRT, and CIRT, respectively. The mean inhomogeneity coefficient was 0.05, 0.07, and 0.02 for 3D-CRT, IMRT, and CIRT respectively. Photon plans resulted in greater volumes of normal tissues at 10% to 95% isodose levels compared with the corresponding carbon ion plans where the volumes increased by a factor of 1.2 to 2.7 for 3D-CRT and 1.2 to 2.0 for IMRT. CONCLUSION CIRT has the potential to improve the target dose conformity, inhomogeneity coefficient, and OAR sparing when compared with 3D-CRT and IMRT. Compared with 3D-CRT, normal tissue exposure was reduced mainly in the mid-to low-isodose levels using IMRT. Additional improvement was obtained using CIRT.
Collapse
Affiliation(s)
- M Amirul Islam
- RNPD, INST, Atomic Energy Research Establishment, Ganakbari, Savar, Dhaka, 1349, Bangladesh.
| | | | | | | | | |
Collapse
|
15
|
Verhey LJ, Chen CC, Chapman P, Loeffler J, Curry WT. Single-Fraction Stereotactic Radiosurgery for Intracranial Targets. Neurosurg Clin N Am 2006; 17:79-97, v. [PMID: 16793501 DOI: 10.1016/j.nec.2006.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Stereotactic radiosurgery (SRS) is a technique for treating intracranial lesions with a high dose of ionizing radiation, usually in a single session, using a stereotactic apparatus for accurate localization and patient immobilization. This article describes several modalities of SRS and some of its applications, particularly for intracranial lesions.
Collapse
Affiliation(s)
- Lynn J Verhey
- Department of Radiation Oncology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.
| | | | | | | | | |
Collapse
|
16
|
|
17
|
Affiliation(s)
- Natia Esiashvili
- Department of Radiation Oncology, Emory University, Atlanta, Georgia, USA
| | | | | |
Collapse
|
18
|
Mock U, Georg D, Bogner J, Auberger T, Pötter R. Treatment planning comparison of conventional, 3D conformal, and intensity-modulated photon (IMRT) and proton therapy for paranasal sinus carcinoma. Int J Radiat Oncol Biol Phys 2004; 58:147-54. [PMID: 14697432 DOI: 10.1016/s0360-3016(03)01452-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE To determine the potential improvements in patients with paranasal sinus carcinoma by comparing proton and intensity-modulated radiotherapy (IMRT) with conventional and conformal photon treatment planning techniques. METHODS AND MATERIALS In 5 patients, comparative treatment planning was performed by comparing proton plans and related conventional, conformal, and IMRT photon plans. The evaluations analyzed dose-volume histogram findings of the target volumes and organs at risk (OARs, i.e., pituitary gland, optical pathway structures, brain, nontarget tissue). RESULTS The mean and maximal doses, dose inhomogeneities, and conformity indexes for the planning target volumes were comparable for all techniques. Photon plans resulted in greater volumes of irradiated nontarget tissues at the 10-70% dose level compared with the corresponding proton plans. The volumes thereby increased by a factor of 1.3-3.1 for conventional, 1.1-3.8 for conformal, and 1.1-3.7 for IMRT. Compared with conventional techniques, conformal and IMRT photon treatment planning options similarly reduced the mean dose to the OARs. The use of protons further reduced the mean dose to the OARs by up to 65% and 62% compared with the conformal and IMRT technique, respectively. CONCLUSION Compared with conventional treatment techniques, conformal RT and IMRT similarly enabled dose reductions to the OARs. Additional improvements were obtained using proton-based treatment planning modalities.
Collapse
Affiliation(s)
- Ulrike Mock
- Department of Radiotherapy and Radiobiology, University Hospital Vienna, Vienna, Austria.
| | | | | | | | | |
Collapse
|
19
|
Bond JE, Smith V, Yue NJ, Knisely JPS. Comparison of an image registration technique based on normalized mutual information with a standard method utilizing implanted markers in the staged radiosurgical treatment of large arteriovenous malformations. Int J Radiat Oncol Biol Phys 2003; 57:1150-8. [PMID: 14575848 DOI: 10.1016/s0360-3016(03)01568-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE To compare a noninvasive technique based on normalized mutual information for registering image sets associated with staged radiosurgical treatments of large arteriovenous malformations (AVMs), with a gold-standard method using radiographically evident markers implanted in the skull. METHODS Nine patients receiving multistage treatment of large AVMs at the University of California at San Francisco (UCSF) gamma knife facility were included in this study. For each patient, the transformations of shot coordinates between a reference treatment stage and subsequent treatment stages were determined at UCSF, based on radiographically defined coordinates of implanted markers in each stereotactic space. A magnetic resonance (MR) image set was acquired for each treatment stage, and used for treatment planning. The two MR image sets for each treatment pair were sent to Yale for an unbiased, independent analysis of shot transformations. An image registration technique based on normalized mutual information was used to produce a single fused image study for each treatment pair. External copper sulfate fiducial markers for both image sets were evident on the fused images, allowing coordinates in both stereotactic systems to be defined. Coordinate transformation between the two systems was determined, based on digitized coordinates of seven common fiducial marker images. RESULTS The average measured overall root-mean-square discrepancy between the Yale and UCSF transformed shot coordinates is 1.1 +/- 0.3 mm. The corresponding error in Yale transformed coordinates is 1.0 +/- 0.3 mm, assuming an inherent 0.5 mm error in the UCSF method. CONCLUSIONS The normalized mutual information method can be used to obtain good image registration between successive sessions in staged treatments. Further improvements in the reported methodology are outlined. Because the mutual information method is less invasive than the implanted marker method, it may be preferable in many cases.
Collapse
Affiliation(s)
- James E Bond
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520-8040, USA.
| | | | | | | |
Collapse
|
20
|
|
21
|
Ma L, Chin LS, DiBiase SJ, Gullapalli R, Kennedy A, Simard JM, Slawson R. Concomitant boost of stratified target area with gamma knife radiosurgery: a treatment planning study. Am J Clin Oncol 2003; 26:e100-5. [PMID: 12902906 DOI: 10.1097/01.coc.0000077935.12142.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Conventional Gamma Knife Stereotactic Radiosurgery (GKSRS) has been focused on delivering a single peripheral dose to the gross target volume based on the anatomic information derived from the magnetic resonance or computed tomography (CT) studies. In this study, we developed a treatment planning approach that allows a boost dose to be delivered concomitantly to the desired subtarget area while maintaining the peripheral isodose coverage of the target volume. The subtarget area is defined as the high-risk or the tumor burden areas based on the functional imaging information such as the magnetic resonance spectroscopy (MRS) studies or the physician's clinical diagnosis. Treatment plan comparisons were carried out between the concomitant boost plans and the conventional treatment plans using dose volume histogram (DVH), tissue volume ratio (TVR), and the maximum dose to the peripheral dose ratio (MD/PD) analysis. Using the concomitant boost approach, more conformal and higher dose was delivered to the desired subtarget area while maintaining the peripheral isodose coverage of the gross target volume (GTV). Additionally, the dose to the normal brain tissue was found to be equivalent between the concomitant boost plans and the conventional plans. As a result, we conclude that concomitant boost of a stratified target area is feasible for GKSRS.
Collapse
Affiliation(s)
- Lijun Ma
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore 21201, USA.
| | | | | | | | | | | | | |
Collapse
|
22
|
Vernimmen FJ, Harris JK, Wilson JA, Melvill R, Smit BJ, Slabbert JP. Stereotactic proton beam therapy of skull base meningiomas. Int J Radiat Oncol Biol Phys 2001; 49:99-105. [PMID: 11163502 DOI: 10.1016/s0360-3016(00)01457-7] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To review outcomes for patients with skull base meningiomas treated using the stereotactic proton beam at the National Accelerator Center (NAC), Republic of South Africa. METHODS AND MATERIALS Since 1993, 27 patients with intracranial meningiomas have been treated stereotactically with protons at NAC. Of those, 23 were located on the skull base, were large or had complex shapes, and were treated with radical intent. Both stereotactic radiotherapy (SRT, 16 or more fractions) and hypofractionated stereotactic radiotherapy (HSRT, 3 fractions) were used. Eighteen patients underwent proton HSRT, while 5 patients were treated with SRT. The mean target volume for the HSRT group was 15.6 cm(3) (range 2.6-63 cm(3)). The mean ICRU reference dose was 20.3 cobalt Gray equivalent (CGyE), and the mean minimum planning target dose was 16.3 CGyE. The mean clinical and radiologic follow-up periods were 40 and 31 months respectively. The mean volume in the SRT group was 43.7 cm(3), with ICRU reference doses ranging from 54 CGyE in 27 fractions to 61.6 CGyE in 16 fractions. RESULTS In the HSRT group, 16/18 (89%) of patients remained clinically stable or improved, while 2/18 (11%) deteriorated. Radiologic control was achieved in 88% of patients, while 2 patients had a marginal failure. Among the 5 SRT patients, 2 were clinically better, and 3 remained stable. All SRT patients achieved radiologic control. Three patients (13%), 2 of them in the HSRT group, suffered permanent neurologic deficits. Analyzing different dose/fractionation schedules, an alpha/beta value of 3.7 Gy for meningiomas is estimated. CONCLUSION Proton irradiation is effective and safe in controlling large and complex-shaped skull base meningiomas.
Collapse
Affiliation(s)
- F J Vernimmen
- Department of Radiation Oncology, Tygerberg Hospital, Tygerberg, South Africa.
| | | | | | | | | | | |
Collapse
|
23
|
Knisely JP, Bond JE, Yue NJ, Studholme C, de Lotbinière ACJ. Image registration and calculation of a biologically effective dose for multisession radiosurgical treatments. J Neurosurg 2000. [DOI: 10.3171/jns.2000.93.supplement_3.0208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
✓ The purpose of this study was to develop techniques for registering image sets associated with staged or multifraction radiosurgical treatments of large targets with the Leksell gamma knife to transform shot coordinates between treatment sessions and produce cumulative dose distributions and to investigate the theoretical biological effects of such protracted treatments by means of such concepts as the linear—quadratic model and biologically effective dose.
An image registration technique based on normalized mutual information was adapted to produce one fused-image study from an imaging series acquired during distinct treatment sessions. A spreadsheet computer program was developed to determine coordinate transformations between the associated stereotactic coordinate systems based on digitized coordinates of fiducial markers appearing on the fused images. Coordinates of shots used during one treatment session could then be transformed to the stereotactic space of another session, and cumulative dose distributions could be computed. The procedure was applied to the two-stage treatment of a giant arteriovenous malformation (AVM). Overall uncertainty in each transformed shot position is approximately 0.7 mm.
An effective single-fraction dose (Deff) was defined and computed for the two-stage AVM treatment. The simple summed dose distribution was compared with the Deff distribution. Because dose values differ significantly in overlap regions between the individual distributions, the clinical usefulness of the simple cumulative distribution is dubious. It may be useful for a future update of the GammaPlan treatment planning software to generate effective single-session dose distributions for such cases.
Collapse
|
24
|
Fuss M, Hug EB, Schaefer RA, Nevinny-Stickel M, Miller DW, Slater JM, Slater JD. Proton radiation therapy (PRT) for pediatric optic pathway gliomas: comparison with 3D planned conventional photons and a standard photon technique. Int J Radiat Oncol Biol Phys 1999; 45:1117-26. [PMID: 10613303 DOI: 10.1016/s0360-3016(99)00337-5] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Following adequate therapy, excellent long-term survival rates can be achieved for patients with optic pathway gliomas. Therefore, avoidance of treatment-related functional long-term sequelae is of utmost importance. Optimized sparing of normal tissue is of primary concern in the development of new treatment modalities. The present study compares proton radiation therapy (PRT) with a three-dimensional (3D)-planned multiport photon and a lateral beam photon technique for localized and extensive optic pathway tumors. METHODS AND MATERIALS Between February 1992 and November 1997, seven children with optic pathway gliomas underwent PRT. For this study, we computed proton, 3D photon, and lateral photon plans based on the same CT data sets, and using the same treatment planning software for all plans. Radiation exposure for normal tissue and discrete organs at risk was quantified based on dose-volume histograms. RESULTS Gross tumor volume (GTV) ranged from 3.9 cm3 to 127.2 cm3. Conformity index (relation of encompassing isodose to GTV volume) was 2.3 for protons, 2.9 for 3D photons, and 7.3 for lateral photons. The relative increase of normal tissue (NT) encompassed at several isodose levels in relation to NT encompassed by the 95% proton isodose volume was computed. Relative NT volume of proton plan isodoses at the 95%, 90%, 80%, 50%, and 25% isodose level increased from 1 to 1.6, 2.8, 6.4, to a maximum of 13.3. Relative volumes for 3D photons were 1.6, 2.4, 3.8, 11.5, and 34.8. Lateral plan relative values were 6, 8.3, 11.5, 19.2, and 26.8. Analysis for small (<20 cm3) and larger (> 80 cm3) tumors showed that protons encompassed the smallest volumes of NT at all isodose levels. Comparable conformity and high-dose gradient were achieved for proton and 3D photon plans in small tumors. However, with increasing tumor volume and complexity, differences became larger. At the 50% isodose level, 3D photons were superior to lateral photons for small tumors; this advantage was equalized for larger tumors. At the lowest isodose level, 3D photons encompassed the highest amount of NT. Analysis of organs at risk showed that PRT reduced doses to the contralateral optic nerve by 47% and 77% compared to 3D photons and lateral photons, respectively. Reductions were also seen for the chiasm (11% and 16%) and pituitary gland (13% and 16%), with differences at clinically relevant tolerance levels. Furthermore, reduced dose exposure of both temporal lobes (sparing 39% and 54%) and frontal lobes was achieved with PRT. CONCLUSION PRT offered a high degree of conformity to target volumes and steep dose gradients, thus leading to substantial normal tissue sparing in high- and low-dose areas. It is expected that this will result in decreased long-term toxicity in the maturing child. Advantages of proton versus 3D photon plans became increasingly apparent with increasing target size and tumor complexity. Even in small tumors, conformity of 3D photon irradiation came at the expense of a larger amount of NT receiving moderate to low radiation doses. Lateral photons resulted in inferior dose distribution with high radiation exposure of clinically relevant normal tissues.
Collapse
Affiliation(s)
- M Fuss
- Department of Radiation Medicine, Loma Linda University Medical Center, CA, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Ma L, Xia P, Verhey LJ, Boyer AL. A dosimetric comparison of fan-beam intensity modulated radiotherapy with Gamma Knife stereotactic radiosurgery for treating intermediate intracranial lesions. Int J Radiat Oncol Biol Phys 1999; 45:1325-30. [PMID: 10613329 DOI: 10.1016/s0360-3016(99)00340-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To compare and evaluate treatment plans for the fan-beam intensity modulated radiotherapy and the Gamma Knife radiosurgery for treating medium-size intracranial lesions (range 4-25 cm3). METHODS AND MATERIALS Treatment plans were developed for the Leksell Gamma Knife and a fan-beam inverse treatment planning system for intensity modulated radiotherapy. Treatment plan comparisons were carried out using dose-volume histogram (DVH), tissue-volume ratio (TVR), and maximum dose to the prescription dose (MDPD) ratio. The study was carried out for both simulated targets and clinical targets with irregular shapes and at different locations. RESULTS The MDPD ratio was significantly greater for the Gamma Knife plans than for the fan-beam IMRT plans. The Gamma Knife plans produced equivalent TVR values to the fan-beam IMRT plans. Based on the DVH comparison, the fan-beam IMRT delivered significantly more dose to the normal brain tissue than the Gamma Knife. The results of the comparison were found to be insensitive to the target locations. CONCLUSION The Gamma Knife is better than the fan-beam IMRT in sparing normal brain tissue while producing equivalent tumor dose conformity for treating medium-size intracranial lesions. However, the target dose homogeneity is significantly better for the fan-beam IMRT than for the Gamma Knife.
Collapse
Affiliation(s)
- L Ma
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore 21201, USA.
| | | | | | | |
Collapse
|
26
|
Platoni K, Lefkopoulos D, Grandjean P, Schlienger M. [Implementation of receiver operating characteristics for the quantitative evaluation of stereotactic radiotherapy treatment plans]. Cancer Radiother 1999; 3:494-502. [PMID: 10630163 DOI: 10.1016/s1278-3218(00)88257-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The definition of criteria and of a methodology dedicated to the quantitative evaluation of conformal stereotactic treatment plans is presented. We implemented the 'Receiver Operating Characteristics' (ROC) analysis, already used in medical imaging, for the quantitative evaluation of irradiation treatment plans. This implementation is based on data provided by dose-volume histograms (DVH). Three techniques, each one using a different dosimetric criterion, were defined for the choice of a reference isodose for a given treatment plan. We used this ROC analysis for the selection of the most conformal treatment plan and its reference isodose among the treatment plans proposed for one patient. This study revealed the interest of ROC analysis based on dose-volume histograms for the quantitative evaluation of treatment plans.
Collapse
Affiliation(s)
- K Platoni
- Département de radiothérapie-oncologie, hôpital Tenon, Paris, France
| | | | | | | |
Collapse
|
27
|
Abstract
Field shaping for stereotactic radiosurgery and stereotactic radiotherapy has evolved from static field shaping techniques applied to static or arc fields and now includes dynamic field shaping definition which can be dynamically modified during the arc. This allows greater conformation of dose to the target volume while minimizing dose to surrounding normal tissue. This results in treatment to a single isocenter, which simplifies the treatment planning and dose delivery, thereby minimizing treatment time and improving patient comfort and satisfaction during the treatment. A number of optimization techniques remain to be investigated.
Collapse
Affiliation(s)
- D D Leavitt
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City 84132, USA
| |
Collapse
|
28
|
Poffenbarger BA, Podgorsak EB. Viability of an isocentric cobalt-60 teletherapy unit for stereotactic radiosurgery. Med Phys 1998; 25:1935-43. [PMID: 9800701 DOI: 10.1118/1.598383] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The potential for radiosurgery with an isocentric teletherapy cobalt unit was evaluated in three areas: (1) the physical properties of radiosurgical beams, (2) the quality of radiosurgical dose distributions obtained with four to ten noncoplanar converging arcs, and (3) the accuracy with which the radiosurgical dose can be delivered. In each of these areas the cobalt unit provides a viable alternative to an isocentric linear accelerator (linac) as a radiation source for radiosurgery. A 10 MV x-ray beam from a linac used for radiosurgery served as a standard for comparison. The difference between the 80%-20% penumbras of stationary radiosurgical fields in the nominal diameter range from 10 to 40 mm of the cobalt-60 and 10 MV photon beams is remarkably small, with the cobalt-60 beam penumbras, on average, only about 0.7 mm larger than those of the linac beam. Differences between the cobalt-60 and 10 MV radiosurgical treatment plans in terms of dose homogeneity within the target volume, conformity of the prescribed isodose volume to the target volume, and dose falloffs outside the target volume are also minimal, and therefore of essentially no clinical significance. Moreover, measured isodose distributions for a radiosurgical procedure on our Theratron T-780 cobalt unit agreed with calculated distributions to within the +/- 1 mm spatial and +/- 5% numerical dose tolerances, which are generally specified for radiosurgery. The viability of isocentric cobalt units for radiosurgery will be of particular interest to centers in developing countries where cobalt units, because of their relatively low costs, provide the only megavoltage source of radiation for radiotherapy, and could easily and inexpensively be modified for radiosurgery. Of course, the quality assurance protocols and mechanical condition of a particular teletherapy cobalt unit must meet stringent requirements before the use of the unit for radiosurgery can be advocated.
Collapse
Affiliation(s)
- B A Poffenbarger
- McGill University, Department of Medical Physics, Montreal General Hospital, Québec, Canada
| | | |
Collapse
|
29
|
Gibon D, Rousselle I, Caudrelier JM, Decool R, Rousseau J. [Progress in dosage optimization for stereotactic radiosurgery]. Cancer Radiother 1998; 2:115-26. [PMID: 9749106 DOI: 10.1016/s1278-3218(98)89082-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Stereotactic radiosurgery is a technique for treatment of intracranial lesions requiring high precision in all steps--from image acquisition to final irradiation. One of most difficult steps is the treatment planning phase, consisting of determination of irradiation parameters sufficient to cover the target volume by avoiding sensitive volumes. A manual and empirical definition can be very long and difficult, especially in the case of complex target volumes situated in sensitive zones. As in conventional radiotherapy, stereotactic radiosurgery has taken advantages from dosimetric optimization. The question is: "What is the configuration of irradiation parameters used in order to obtain the treatment plan by satisfying defined constraints?". The purpose of this article is to summarize optimization methods used in radiosurgery and to describe the technical alternatives proposed for this treatment as well as the possibilities of plan evaluation between different techniques. This purpose will be illustrated by the optimization methodology used in the Center Oscar Lambret of Lille, France for the radiosurgical treatment with linear accelerator.
Collapse
Affiliation(s)
- D Gibon
- Département de radiothérapie, Centre Oscar-Lambret, Lille, France
| | | | | | | | | |
Collapse
|
30
|
Verhey LJ, Smith V, Serago CF. Comparison of radiosurgery treatment modalities based on physical dose distributions. Int J Radiat Oncol Biol Phys 1998; 40:497-505. [PMID: 9457840 DOI: 10.1016/s0360-3016(97)00720-7] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE As a means of selecting the optimal stereotactic radiosurgery (SRS) treatment modality, a comparison of physical dose distributions to defined targets and nontarget brain tissue has been made for a group of test cases selected to represent a range of treatment-planning situations from small, nearly spherical volumes to large irregular volumes. METHODS AND MATERIALS Plans were developed for each case using photon beams from the Leksell Gamma Unit (LGU), multiarc bremsstrahlung photon beams from a linear accelerator (linac) and proton beams, with the objective of encompassing the target as closely as possible with the prescription isodose line, and minimizing dosage to normal tissue within the bounds of standard clinical practice. Dose-volume histograms (DVHs) were calculated for target and for nontarget brain tissue and compared for the various modalities. RESULTS In general, protons delivered less dosage to normal brain than other modalities for large and peripheral lesions and LGU plans were more successful at conforming to highly irregular shapes than conventional linac plans. CONCLUSIONS Differences were observed to depend on treatment modality, target characteristics (shape, size and location), and the amount of effort expended on treatment planning and the time allotted for treatment implementation.
Collapse
Affiliation(s)
- L J Verhey
- Department of Radiation Oncology, University of California, San Francisco 94143-0226, USA.
| | | | | |
Collapse
|
31
|
Smith V, Verhey L, Serago CF. Comparison of radiosurgery treatment modalities based on complication and control probabilities. Int J Radiat Oncol Biol Phys 1998; 40:507-13. [PMID: 9457841 DOI: 10.1016/s0360-3016(97)00721-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE The relative efficacy of Gamma Knife, Linac, and Proton treatment modalities for stereotactic radiosurgery (SRS) was investigated on the basis of normal tissue complication probability (NTCP) and tumor control probability (TCP), calculated for representative test cases. METHODS AND MATERIALS Five radiosurgery patient cases were selected to cover a range of treatment-planning situations from small spherical volumes to large irregular volumes. A target volume consisting of contours drawn on CT transverse slices was prepared for each case. Plans were developed using the three treatment modalities for each case, with the objective of encompassing the target as closely as possible with a prescription isodose line and minimizing dose to normal tissue, within the constraints of current clinical practice. Dose-volume histograms (DVH) were calculated for the target and for normal tissue, and these histograms were used to calculate NTCP and TCP values for each plan. RESULTS AND CONCLUSIONS Differences in NTCP and TCP values were found to depend on treatment modality, size, shape, and location of the target, the amount of effort devoted to treatment planning, and the complexity of the plan.
Collapse
Affiliation(s)
- V Smith
- Department of Radiation Oncology, University of California, San Francisco 94143-0226, USA.
| | | | | |
Collapse
|
32
|
Prasad SG, Parthasaradhi K, Des Rosiers C, Bloomer WD, LaCombe MA. Dosimetric analysis and clinical implementation of 6 MV X-ray radiosurgery beam. Med Dosim 1997; 22:127-33. [PMID: 9243467 DOI: 10.1016/s0958-3947(97)00010-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The dosimetric data on tissue maximum ratios (TMR), output factors, off axis ratios and beam profiles are presented for small circular fields of diameters ranging from 12.5 to 40 mm for 6 MV radiosurgery beam. It is noticed that dmax increases as the collimator field size increases. Comparison of our data with the published TMR and output factors of similar small circular fields shows that our values are higher than those data. Similarities in trend are noticed with the published isodose volumes for 1-5 and 10 arcs. Not much variation is seen beyond two arcs for 80% isodose volumes for all the field sizes. The variation is small in 20% isodose volumes beyond three arcs. Variations are noticed in 5% isodose volumes for 12.5 mm diameter collimated beam. Our experience has been exclusively with malignant neoplasms. An ideal target volume is covered by 80% isodose volume with 3-4 arcs and a single isocenter. Sixteen patients have been treated to date at our institution, including one patient with brain metastases, two patients with meningiomas, one patient with lymphoma and 12 patients with astrocytomas. The majority of tumors have been treated with single isocenter but some as large as 7 cm have been treated safely with two isocenters.
Collapse
Affiliation(s)
- S G Prasad
- Evanston Hospital Corporation, Division of Medical Physics, Northwestern University Medical School, IL 60201, USA
| | | | | | | | | |
Collapse
|
33
|
Abstract
Rapid developments in technology will have a profound effect on veterinary radiation oncology. These developments include computer-enhanced, three-dimensional treatment planning and smaller, more compact, more reliable radiation equipment, primarily linear accelerators. For treatment of all veterinary patients, the linear accelerators need electron capability. Although fractionated therapy will remain the standard from of treatment, new modalities, including a highly precise single-dose treatment called radiosurgery, and a precise fractionated therapy called conformal therapy, will be utilized more in the future.
Collapse
Affiliation(s)
- P R Gavin
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, USA
| |
Collapse
|
34
|
Levy RP, Schulte RW, Frankel KA, Steinberg GK, Marks MP, Lane B, Heilbronn LH, Meinass HJ, Galindo RA, Slater JD, Slater JM. Computed tomography slice-by-slice target-volume delineation for stereotactic proton irradiation of large intracranial arteriovenous malformations: an iterative approach using angiography, computed tomography, and magnetic resonance imaging. Int J Radiat Oncol Biol Phys 1996; 35:555-64. [PMID: 8655380 DOI: 10.1016/s0360-3016(96)80019-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE Target-volume delineation for stereotactic irradiation is problematic for large and irregularly shaped arteriovenous malformations (AVMs). The purpose of this report is to quantify modifications in the target volume that result from iterative treatment planning that incorporates multimodality imaging data. METHODS AND MATERIALS Stereotactic neuroimaging procedures were performed for 20 consecutive patients with AVM volumes > 10 cm3. Angiographically defined extrema were transformed into computed tomography (CT) space. The resulting target contours were then modified by a multidisciplinary treatment planning team after iterative review of angiographic, CT, and magnetic resonance imaging (MRI) data. Volumes of interest and dose-volume histograms for proton irradiation were calculated before and after iterative target delineation. RESULTS Initial (angiographically defined) target volumes ranged from 15.3 to 96.1 cm3 (mean, 43.6 cm3). Final (iteratively defined) target volumes ranged from 10.7 to 114.0 cm3 (mean, 38.4 cm3). The volume of presumed normal tissue excluded by iterative planning ranged from 2.6 to 47.0 cm3 (mean, 15.5 cm3). Initially untargeted AVM, most commonly obscured by embolization material, was identified in all cases (range, 0.3 to 57.8 cm3; mean, 10.3 cm3). Corresponding dose-volume histograms demonstrated marked differences regarding lesion coverage and sparing of normal tissue structures. CONCLUSIONS Iterative target-volume delineation resulted in significant modifications from initial, angiographically defined target volumes. Substantial amounts of apparently normal tissue were excluded from the final target, and additional abnormal vascular structures were identified for incorporation. We conclude that an iterative multimodality approach to target-volume delineation may improve the overall results for stereotactic irradiation of large and complex AVMs.
Collapse
Affiliation(s)
- R P Levy
- Department of Radiation Medicine, Loma Linda University Medical Center, CA 92354,USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Petrovich Z, Luxton G, Formenti S, Jozsef G, Zee CS, Apuzzo ML. Stereotactic radiosurgery for primary and metastatic brain tumors. Cancer Invest 1996; 14:445-54. [PMID: 8816860 DOI: 10.3109/07357909609018902] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Z Petrovich
- Department of Radiation Oncology, University of Southern California School of Medicine, Los Angeles, USA
| | | | | | | | | | | |
Collapse
|
36
|
|
37
|
Colombo F, Francescon P, Cora S, Testolin A, Chierego G. Evaluation of linear accelerator radiosurgical techniques using biophysical parameters (NTCP and TCP). Int J Radiat Oncol Biol Phys 1995; 31:617-28. [PMID: 7852128 DOI: 10.1016/0360-3016(94)00348-o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE Several irradiation techniques are compared with regard to normal tissue complication probability and tumor control probability. METHODS AND MATERIALS Normal tissue complication probability is calculated using a model based on the "critical element architecture." The probability of controlling an inhomogeneously irradiated tumor is calculated using a model that takes into account the heterogeneity of tumors (different radiosensitivity of clonogens within the tumor and the varying number of clonogens among patients with the same kind of tumor). The ratio of tumor control probability to normal tissue complication probability (therapeutic gain factor) at different levels of dose has been used as a score for the analysis of various irradiation techniques. RESULTS The best irradiation techniques depends on many factors: irradiation genometry, irradiation field size, choice of the reference isodose, and it is dictated by the pathology of the lesions (noninfiltrating radioresistant tumors, infiltrating radioresistant tumors, noninfiltrating radiosensitive tumors, infiltrating radiosensitive tumors, arterovenous malformations). For the irradiation of the artero-venous malformations it is proposed to insert on the supplemental collimator a flattening filter to reduce the probability of inducing a poorly syncronized obliterative effect. CONCLUSION We propose that for each kind of pathology to be treated radiosurgically, a proper irradiation strategy should be used.
Collapse
Affiliation(s)
- F Colombo
- Department of Neurosurgery, General Hospital, Vicenza, Italy
| | | | | | | | | |
Collapse
|
38
|
Lefkopoulos D, Schlienger M, Touboul E, Plazas MC, Merienne L. 3-D dosimetric methodology in multiple isocentres radiosurgery: the influence of dose-volume histograms on the choice of the reference isodose. Med Biol Eng Comput 1994; 32:440-6. [PMID: 7967812 DOI: 10.1007/bf02524699] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- D Lefkopoulos
- Department of Radiotherapy, Hopital Tenon, Paris, France
| | | | | | | | | |
Collapse
|
39
|
Wilder RB. Treatment of arteriovenous malformations with stereotactic radiosurgery:A review. ACTA ACUST UNITED AC 1994. [DOI: 10.1002/roi.2970020202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
40
|
Soto Torres J. Radiocirugía con acelerador de protones. Neurocirugia (Astur) 1994. [DOI: 10.1016/s1130-1473(94)71092-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
41
|
Delannes M, Daly-Schveitzer N, Sabatier J, Bonnet J. Fractionated brain stereotactic irradiation using a non-invasive frame:Technique and preliminary results. ACTA ACUST UNITED AC 1994. [DOI: 10.1002/roi.2970020206] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
42
|
Chierego G, Francescon P, Colombo F, Pozza F. From radiotherapy to stereotactic radiosurgery: physical and dosimetrical considerations. Radiother Oncol 1993; 29:214-8. [PMID: 8310148 DOI: 10.1016/0167-8140(93)90249-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The aim of this presentation is to analyse the mechanical and dosimetrical parameters of the linear accelerator used in stereotactic radiosurgery. The use of the thimble and Markus chambers, TL and film in small field dosimetry are investigated. To determine the optimal irradiation technique and dose distribution, the dose volume to healthy tissue is considered.
Collapse
Affiliation(s)
- G Chierego
- Department of Medical Physics, General Hospital, Vicenza, Italy
| | | | | | | |
Collapse
|
43
|
Lefkopoulos D, Schlienger M, Touboul E. A 3-D radiosurgical methodology for complex arteriovenous malformations. Radiother Oncol 1993; 28:233-40. [PMID: 8256001 DOI: 10.1016/0167-8140(93)90063-e] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 3-D methodology, the associated targets methodology, for planning radiosurgical irradiations of complex arteriovenous malformations (AVMs) is presented. It uses the ARTEMIS-3D treatment planning system and has been devised and adopted by our group since January 1990. Its main features are: (a) prescription and delivery of a minimal target dose on the surface of the lesion, corresponding to a 60-70% isodose range. The dose to adjacent functional neurological structures is taken into account as well as the maximum dose to the lesion; (b) An optimisation approach consisting of obtaining the optimal superimposition of the isodose surface and the 3-D contour of the lesion and sharp fall-offs by interactive manipulation of the treatment parameters. The clinical choice of the treatment plan is based on a compromise between the optimal reference isodose surface encompassing the lesion and the minimisation of the volumetric dose fall-off. In complex AVMs the angiographic results have been significantly improved in comparison with our previous experience because of the better achieved lesion encompassing.
Collapse
Affiliation(s)
- D Lefkopoulos
- Department of Radiation Oncology, Tenon Hospital, Paris, France
| | | | | |
Collapse
|
44
|
|
45
|
Luxton G, Petrovich Z, Jozsef G, Nedzi LA, Apuzzo ML. Stereotactic radiosurgery: principles and comparison of treatment methods. Neurosurgery 1993; 32:241-59; discussion 259. [PMID: 8437663 DOI: 10.1227/00006123-199302000-00014] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Methods of stereotactic radiosurgery are reviewed and compared with respect to technical factors and published clinical results. Heavy-ion beams, the Leksell cobalt-60 gamma knife, and the conventional linear accelerator (linac) are compared with respect to dosimetry, radiobiology, treatment planning, cost, staffing requirements, and ease of use. Clinical results on the efficacy of treatment of arteriovenous malformations are tabulated, and other applications of radiosurgery are described. It is concluded that although there are dosimetric and radiobiological advantages to charged-particle beams that may ultimately prove critical in the application of radiosurgery to large (> 30 mm) lesions, these advantages have not yet demonstrated clinical effect. On the other hand, equally excellent clinical results are obtained for small lesions with photon beams--the gamma knife and the linac. There are only minor differences between gamma and x-ray beam dose distributions for small, spherical-shaped targets. Mechanical precision is superior for the gamma knife as compared with the linac. The superior mechanical precision is of limited importance for most clinical targets, because inaccuracy of cranial target localization based on radiological imaging is greater than the typical linac imprecision of +/- 1 mm. Treatment planning for the linac is not standardized, but existing systems are based on well-known algorithms. The linac allows flexible, ready access to individualized beam control, without intrinsic field size limitations. Thus, it is more readily possible to achieve homogeneous dose distributions for nonspherical targets with one or more dimensions greater than 25 mm, as compared with that achieved with the gamma unit.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- G Luxton
- Department of Radiation Oncology, University of Southern California School of Medicine, Los Angeles
| | | | | | | | | |
Collapse
|
46
|
Affiliation(s)
- R E Allen
- Department of Dermatology, University of California, School of Medicine, San Francisco 94143
| | | |
Collapse
|
47
|
Abstract
In a series of 33 patients with reasonably controlled primary cancers, stereotactic radiosurgery was used to treat 52 brain metastases. After a mean radiological follow-up time of 5.5 months, six lesions (12%) had stabilized in size, 26 (50%) were significantly reduced, and 15 (29%) had disappeared. One large melanoma metastasis progressed relentlessly despite treatment. Five lesions (9%) had decreased in size slightly before enlarging. In two of these lesions, biopsy revealed only necrosis. In almost all cases, treatment was associated with decreased peritumoral edema. However, a group of patients with large metastases and extensive prior brain irradiation has been identified in whom prolonged symptomatic cerebral edema poses a problem. It is concluded that radiosurgery is a viable alternative to surgical resection for some cases of brain metastasis.
Collapse
Affiliation(s)
- J R Adler
- Department of Neurosurgery, Stanford University Medical Center, California
| | | | | | | |
Collapse
|
48
|
Williams JA. Brain tolerance to radiosurgery. J Neurosurg 1992; 76:557-9. [PMID: 1738041 DOI: 10.3171/jns.1992.76.3.0557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
49
|
|
50
|
|