Authors' recommendations: As the most established SRS type, Gamma Knife® has been studied as an option for treating brain lesions in patients who are inoperable or for augmenting surgical treatment. Gamma Knife® offers the precision needed to treat small lesions and lesions near sensitive structures in the brain. The most popular clinical indications studied with Gamma Knife® are brain metastases, AVM, acoustic neuroma, primary malignant lesions, mengioma and pituitary adenoma.The highest quality of evidence is found in RCTs and systematic reviews of RCTs of Gamma Knife® for brain metastases. Evidence for the use of any type of SRS in all other indications is derived from observational data of selected patients designed to assess the feasibility, safety and efficacy of SRS. The few Level III-2 and Level III-3 comparative studies identified in this report have significant limitations in conduct (nonrandomized, retrospective, variable protocols) and reporting which prevent meaningful comparisons between SRS types or other treatment options. This is consistent with the conclusions in the other systematic reviews include in this report. Some caution is warranted for indications (eg. Spinal metastases) where the volume of evidence may appear to be growing based on the number of citations, but careful review indicates considerable redundancy in the reporting of case series from relatively few institutions with experience in SRS.Development of LINAC-based systems may permit SRS to be used not only for local control of primary disease or palliative treatment for solitary metastases, but also in combination with standard chemotherapy as curative therapy for individuals who present with early metastatic disease.5 Okunieff cites the pace of technological development, the need to balance tumor control with toxicity, lack of standardization of SRS techniques, differences in manufacturer calibrations and adjustments across LINAC-based systems, choice of appropriate patients and outcome measures, and ethical considerations as challenges to the design of clinical trials of SRS, but challenges that can be met.The use of SRS is under investigation in many research protocols (See Appendix). Most clinical uses for SRS are in primary brain tumors and metastases to the brain, but protocols for using SRS in non-head and neck indications are emerging as are protocols using LINAC-based systems for boost therapy in selected brain indications. In 2002, the Radiation Therapy Oncology Group (RTOG) in North America began a consensus process for developing multicenter prospective trials in lung cancer using SRS6 . From that process RTOG protocol 0236 was produced using SRS for medically inoperable patients with clinical stage I non-small cell lung cancer. With refinement and experience, this process is being used as a model for designing future RTOG protocols using SRS. The potential for SRS to change the course of cancer survival highlights the need for such trials to assess the value of all types of SRS relative to other treatment options.

Project Status: Completed

URL for project: http://www4.va.gov/VATAP/docs/StereotacticRadiosurgeryUPDATEgammaknife2007tm.pdf

Year Published: 2007

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: VA Technology Assessment Program

Contact Address: Liz Adams, VA Technology Assessment Program, Office of Patient Care Services (11T), VA Boston Healthcare System Room 4D-142, 150 South Huntington Avenue, Boston, MA 02130 USA Tel: +1 617 278 4469; Fax: +1 617 264 6587;

Contact Name: elizabeth.adams@med.va.gov

Contact Email: elizabeth.adams@med.va.gov

Copyright: VA Technology Assessment Program (VATAP)