Ankur Patel M.D.

Prabhu, R.S., Dhakal, R., Vaslow, Z.K., Dan, T., Mishra, M.V., Murphy, E.S., Patel, T.R., Asher, A.L., Yang, K., Manning, M.A., Stern, J.D., Patel, A.R., Wardak, Z., Woodworth, G.F., Chao, S.T., Mohammadi, A. and Burri, S.H. (2021). “Preoperative radiosurgery for resected brain metastases: the PROPS-BM multicenter cohort study.” Int J Radiat Oncol Biol Phys May 28;S0360-3016(21)00666-0. [Epub ahead of print].

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PURPOSE: Preoperative radiosurgery (SRS) is a feasible alternative to postoperative SRS with potential benefits in adverse radiation effect (ARE) and leptomeningeal disease (LMD) relapse. However, previous studies are limited by small patient numbers and single institutional design. Our aim was to evaluate preoperative SRS outcomes and prognostic factors from a large multicenter cohort (Trial name BLINDED). METHODS AND MATERIALS: Patients with brain metastases (BM) from solid cancers, of which at least 1 lesion was treated with preoperative SRS and underwent planned resection were included from 5 institutions. SRS to synchronous intact BM was allowed. Radiographic meningeal disease was categorized as nodular (nMD) or classical “sugarcoating” (cLMD). RESULTS: The cohort included 242 patients with 253 index lesions. Most patients (62.4%) had a single BM, 93.7% underwent gross total resection (GTR), and 98.8% were treated with a single fraction to a median dose of 15 Gy to a median gross tumor volume of 9.9cc. Cavity local recurrence (LR) at 1 and 2-years was 15% and 17.9%, respectively. Subtotal resection (STR) was a strong independent predictor of LR (hazard ratio 9.1, p<0.001). MD and any grade ARE at 1 and 2-years was 6.1% and 7.6%, and 4.7% and 6.8%, respectively. Median and 2-year overall survival (OS) was 16.9 months and 38.4%, respectively. The majority of MD was cLMD type (13 of 19 pts with MD, 68.4%). Ten of 242 pts (4.1%) experienced grade ≥3 postoperative surgical complications. CONCLUSIONS: This multicenter study represents the largest cohort treated with preoperative SRS to our knowledge. The favorable outcomes previously demonstrated in single institution studies are confirmed in this expanded multicenter analysis without evidence of excessive postoperative surgical complication risk. STR, though infrequent, is associated with significantly worse cavity LR. A randomized trial between preoperative and postoperative SRS is warranted and currently being designed.

Mendel, J.T., Schroeder, S., Plitt, A., Patel, A., Joo, M., Stojadinovic, S., Dan, T., Timmerman, R., Patel, T.R. and Wardak, Z. (2021). “Expanded Radiosurgery Capabilities Utilizing Gamma Knife Icon™.” Cureus 13(3): e13998.

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The indications and techniques for the treatment of intracranial lesions continue to evolve with the advent of novel technologies. The Gamma Knife Icon™ (GK Icon™) is the most recent model available from Elekta, providing a frameless solution for stereotactic radiosurgery. At our institution, 382 patients with 3,213 separate intracranial lesions have been treated with frameless stereotactic radiotherapy using the GK Icon. The wide range of diagnoses include brain metastases, meningiomas, arteriovenous malformations, acoustic neuromas, pituitary adenomas, and several other histologies. The ability to perform both frame and frameless treatments on the GK Icon has significantly increased our daily volume by almost 50% on a single machine. Although the frameless approach allows one to take advantage of the precision in radiosurgery, the intricacies regarding treatment with this frameless system are not well established. Our initial experience will help to serve as a guide to those wishing to implement this novel technology in their practice.