Multi-institutional experience of MR-guided stereotactic body radiation therapy for adrenal gland metastases.

While dose escalation is associated with improved local control (LC) for adrenal gland metastases (AGMs), the proximity of gastrointestinal (GI) organs-at-risk (OARs) limits the dose that can be safely prescribed via CT-based stereotactic body radiation therapy (SBRT). The advantages of magnetic resonance-guided SBRT (MRgSBRT), including tumor tracking and online plan adaptation, facilitate safe dose escalation. This is a multi-institutional review of 57 consecutive patients who received MRgSBRT on a 0.35-T MR linac to 61 AGMs from 2019 to 2021. The Kaplan-Meier method was used to estimate overall survival (OS), progression-free survival (PFS), and LC, and the Cox proportional hazards model was utilized for univariate analysis (UVA). Median follow up from MRgSBRT was 16.4 months (range [R]: 1.1-39 months). Median age was 67 years (R: 28-84 years). Primary histologies included non-small cell lung cancer (N = 38), renal cell carcinoma (N = 6), and melanoma (N = 5), amongst others. The median maximum diameter was 2.7 cm (R: 0.6-7.6 cm), and most AGMs were left-sided (N = 32). The median dose was 50 Gy (R: 30-60 Gy) in 5-10 fractions with a median BED We demonstrate that MRgSBRT achieves favorable early LC and no grade 3 + toxicity despite prescribing a median BED

© 2024 The Authors. Published by Elsevier B.V. on behalf of European Society for Radiotherapy and Oncology.

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Rupesh Kotecha has received personal fees from Accuray Inc., Elekta AB, ViewRay Inc., Novocure Inc., Elsevier Inc., Brainlab, Kazia Therapeutics, Castle Biosciences, and institutional research funding from Medtronic Inc., Blue Earth Diagnostics Ltd., Novocure Inc., GT Medical Technologies, AstraZeneca, Exelixis, ViewRay Inc., Brainlab, Cantex Pharmaceuticals, and Kazia Therapeutics. Tugce Kutuk has received a travel stipend from GT Medical Technologies, Inc. Sarah Hoffe has received research funding from ViewRay, Inc, and Galera Pharmaceuticals. Jessica Frakes has received consulting fees from ViewRay, Inc, and a speaker bureau role for Boston Scientific. Evan Wuthrick has received consulting fees from ViewRay, Inc, AlphaTau, Castle, and Varian. Michael Chuong has received personal fees from ViewRay, Sirtex, IBA and institutional research funding from Novocure, ViewRay, and StratPharma. Stephen Rosenberg has received consulting fees and research support from Viewray, Inc., as well as consulting fees and speaker’s honoraria from Novocure, Inc.