Vol 25, No 4 (2020)
Published online: 2020-07-01

open access

Page views 212
Article views/downloads 249
Get Citation

Connect on Social Media

Connect on Social Media

Radiosurgery dose reduction for brain metastases on immunotherapy (RADREMI): A prospective phase I study protocol

Shearwood McClelland1, Tim Lautenschlaeger1, Yong Zang2, Nasser H. Hanna3, Kevin Shiue1, Aaron P. Kamer4, Namita Agrawal1, Susannah G. Ellsworth1, Ryan M. Rhome1, Gordon A. Watson1
DOI: 10.1016/j.rpor.2020.04.007
Rep Pract Oncol Radiother 2020;25(4):500-506.



Up to 20% of patients with brain metastases treated with immune checkpoint inhibitor (ICI) therapy and concomitant stereotactic radiosurgery (SRS) suffer from symptomatic radiation necrosis. The goal of this study is to evaluate Radiosurgery Dose Reduction for Brain Metastases on Immunotherapy (RADREMI) on six-month symptomatic radiation necrosis rates.


This study is a prospective single arm Phase I pilot study which will recruit patients with brain metastases receiving ICI delivered within 30 days before SRS. All patients will be treated with RADREMI dosing, which involves SRS doses of 18 Gy for 0−2 cm lesions, 14 Gy for 2.1−3 cm lesions, and 12 Gy for 3.1−4 cm lesions. All patients will be monitored for six-month symptomatic radiation necrosis (defined as a six-month rate of clinical symptomatology requiring steroid administration and/or operative intervention concomitant with imaging findings consistent with radiation necrosis) and six-month local control. We expect that RADREMI dosing will significantly reduce the symptomatic radiation necrosis rate of concomitant SRS + ICI without significantly sacrificing the local control obtained by the present RTOG 90−05 SRS dosing schema. Local control will be defined according to the Response Assessment in Neuro-Oncology (RANO) criteria.


This study is the first prospective trial to investigate the safety of dose-reduced SRS in treatment of brain metastases with concomitant ICI. The findings should provide fertile soil for future multi-institutional collaborative efficacy trials of RADREMI dosing for this patient population.

Trial Registration

Clinicaltrials.gov identifier: NCT04047602 (registration date: July 25, 2019).

Article available in PDF format

View PDF Download PDF file

Reports of Practical Oncology and Radiotherapy