Control and Toxicity in Melanoma Versus Other Brain Metastases in Response to Combined Radiosurgery and PD-(L)1 Immune Checkpoint Inhibition

oleh: Roman L. Travis, BS, Samuel R. Marcrom, MD, Matthew H. Brown, BS, Mayank P. Patel, MD, James M. Markert, MD, MPH, Kristen O. Riley, MD, Robert Conry, MD, Christopher D. Willey, MD, PhD, Markus Bredel, MD, PhD, John B. Fiveash, MD

Format: Article
Diterbitkan: Elsevier 2021-01-01

Deskripsi

Purpose: Prior studies have mixed conclusions about the efficacy and central nervous system (CNS) toxicity profile of combining radiosurgery with anti-programed cell death 1 (PD-1) immune checkpoint inhibition (ICI) for brain metastases. This study evaluates the safety and efficacy of combined radiosurgery and anti-PD-1 ICI for melanoma, non-small cell lung cancer (NSCLC), and renal cell carcinoma (RCC) brain metastases (BM). Methods and Materials: Forty-one patients with 153 radiation naïve melanoma BM and 33 patients with 118 BM of NSCLC and RCC origin from 2014 through 2019 received radiosurgery and either anti PD-1 receptor inhibition or anti PD-L1 inhibition targeting the PD-1 ligand with less than 4 months separating either therapy. Similar to Radiation Therapy Oncology Group 9005, high-grade CNS toxicity was defined as irreversible grade 3 or any grade 4/5 neurologic event. Salvage resection revealing necrosis and viable tumor was considered grade 4 toxicity and local failure. An increase in greatest cross-sectional diameter of 25% on contrasted magnetic resonance imaging was designated as a local failure. Results: Median follow-up was 10 months (range, 1-41 months). Local control was estimated to be 90.3% at 1 year. Distant control was 38.8% at 1 year, and neither local nor distant control were significantly influenced by limiting steroids to the day of treatment (P = .55, .52 respectively). One-year freedom from high-grade toxicity was 90.4% for patients and 94.6% for tumors. Though melanoma accounted for 41 (55%) patients and 153 (56%) tumors, it accounted for all high-grade toxicities (P = .03). These patients had some combination of high tumor burden, aggressive steroid taper, and treatment with ipilimumab. Conclusions: Stereotactic radiosurgery combined with anti-PD-1 ICI appears to result in a high rate of local tumor control and a low rate of high-grade CNS toxicity, comparable to historical series with radiosurgery alone. High-grade toxicity is more likely in melanoma than RCC and NSCLC. Coming prospective studies will shed light on further questions about treatment timing, steroids, and response.