Post-Surgical Stereotactic Radiotherapy (SRT) Versus GammaTile-ROADS (Radiation One and Done Study)

Summary

Objectives

GammaTile therapy results in improved clinical outcomes; however the data is a single
site experience with a limited number of subjects, only 12 of which were patients with
metastatic brain tumors. The primary objective of this randomized, controlled trial is to
compare the efficacy and safety of intraoperative radiation therapy using GammaTilesTM
(GT) versus SRT 3-4 weeks following metastatic tumor resection which is the current
standard of care. The data collected in this trial design will allow for a direct
comparisons of a variety of outcomes including local control, overall survival,
functional status, quality of life, neurocognitive status and safety in the target
population. In order to support direct comparisons, subjects will be randomized to the
two equally sized arms (1:1) based on the following stratification factors; age (<60 and
=60), duration of extracranial disease control (=3 months vs >3 months), number of
metastases (one vs multiple), histology (lung and radiation resistant), and the maximal
diameter of the index lesion (=3 cm and >3 cm) and use of prior or current immunotherapy
(yes vs no).

An index lesion meeting the criteria of = 2.5cm in maximum diameter and appropriate for
gross total resection (GTR), will be identified and up to three other non-resectable
lesions in a patient will be allowed. After resection of the index lesion, the surgical
bed will be treated with adjunct radiation (either GT or SRT) thereby following the
standard of care guideline. (NCCN Guidelines, 2019). Additional, unresected metastatic
lesions will be treated with stereotactic radiosurgery alone, which also adheres to
standard of care guidelines (NCCN Guidelines, 2019).

GammaTile is an FDA-cleared means of rapid dose delivery of radiation therapy directly to
the tumor bed with predictable dosimetry at the immediate time of re-resection, and a
intense but localized radiation treatment may confer a reduced risk for radiation
necrosis compared to other therapies. It is typically easly placed with minimal
additional operative time and limited staff radiation exposure.

Given these benefits, the rationale for conducting this randomized control comparison
study is to generate additional data, to further support the use of this new FDA-cleared
method of delivering radiation therapy in the setting of newly diagnosed brain
metastases.