Analyzing Preoperative Stereotactic Radiosurgery With Gamma Knife Icon for Brain Metastases

Summary

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Description

INTERVENTION: Enrolled patients will receive stereotactic radiosurgery (SRS) to all metastases followed by surgical resection of resectable metastases within one to 10 days following SRS. Pathologic specimens will be analyzed, and the patient will enter a standard pattern of surveillance (brain MRI ...

INTERVENTION: Enrolled patients will receive stereotactic radiosurgery (SRS) to all metastases followed by surgical resection of resectable metastases within one to 10 days following SRS. Pathologic specimens will be analyzed, and the patient will enter a standard pattern of surveillance (brain MRI every three months for two years). STUDY RATIONALE: Given the increased risk of leptomeningeal failure with surgery followed by SRS as well as the risk of radiation necrosis, new paradigms in therapy delivery and sequencing are being explored. Areas of investigation include optimization of target volume, marginal expansion, multi-fractionation, timeliness of SRS after surgery, and delivery of SRS prior to surgical resection. In theory, advantages of preoperative SRS include better target delineation, sterilization of tumor cells prior to surgical disruption of the tumor, vascular supply, and CSF spaces, and resection of tissue that would otherwise be at risk of radiation necrosis. In 2014, Asher, et al. (Asher AL, Burri SH, Wiggins WF, et al. A new treatment paradigm: neoadjuvant radiosurgery before surgical resection of brain metastases with analysis of local tumor recurrence. Int J Radiat Oncol Biol Phys 2014;88:899-906.) reported that the use of neoadjuvant SRS prior to surgery was both safe and effective (even for metastases >3 cm) with no reported leptomeningeal recurrences or radiation necrosis. More recently, Patel et al. (Patel KR, Burri SH, Asher AL, et al. Comparing Preoperative With Postoperative Stereotactic Radiosurgery for Resectable Brain Metastases: A Multi-institutional Analysis. Neurosurgery 2016;79:279-85.) performed a retrospective comparison of preoperative versus postoperative SRS and reported no difference in local control, distant brain failure, or overall survival. Furthermore, the authors reported significantly lower rates of leptomeningeal carcinomatosis and radiation necrosis with preoperative SRS. Huff, et al. (Huff WX, Agrawal N, Shapiro S, et al. Efficacy of pre-operative stereotactic radiosurgery followed by surgical resection and correlative radiobiological analysis for patients with 1-4 brain metastases: study protocol for a phase II trial. Radiat Oncol 2018;13:252.) recently published a protocol for a phase II prospective trial designed to compare outcomes using preoperative SRS versus historically cited outcomes for postoperative SRS. This pilot study mirrors this design and aims to confirm study feasibility and to assess local control, central nervous system (CNS) progression-free survival, overall survival, rates of leptomeningeal spread, rates of radiation necrosis, and quality of life measures with the use of preoperative SRS.

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