Stereotactic radiosurgery for the treatment of brain metastasis from gastrointestinal primary cancers
Nitika Paudel, Irene Helenowski, Liam Kane, Sean Sachdev, Orin Bloch, Matthew Tate, James P. Chandler and Tim J. Kruser
Purpose: We aimed to determine the efficacy of gamma knife stereotactic radiosurgery (SRS) to control brain metastases (BM) from GI primaries and report on the patient outcomes. Materials/methods: We retrospectively evaluated patients who had undergone SRS at our institution for the treatment BM from GI primaries from 2000 to 2016. Actuarial rates for overall survival (OS) and local control (LC) were calculated. Survival rates were computed via the Kaplan-Meier method from the day of SRS. Multivariate analysis (MVA) using proportional hazards regression was done to determine prognostic factors for OS and LC.
Results: 53 patients with a total of 148 BM were treated with SRS. The median age at SRS was 60 years and the median treatment dose was 18 Gy. SRS was given as an adjuvant treatment to 30.4% of lesions. Twelve patients underwent second course of SRS for new/recurrent lesions at a median of 8 months from the first SRS (range 2-25.5). Twelve patients (22.6%) received salvage whole brain radiation. The median follow up time from the diagnosis of BM was 6 months. Local control rate at 6 months was 74.33% and 57.21% at 12 months. The OS at 1 year was 34% and 8% at 3 years. On MVA, higher GK dose was associated with better LC, and and >10 BM trended towards higher risk of local recurrence (LR). None of the tested factors proved to be significant for OS on MVA. No radiographic radionecrosis was observed on follow up MRI.
Conclusions: SRS is a safe treatment modality for the management of CNS metastases from GI primary. Consideration for dose-escalated approaches may improve LC rates.
Keywords: stereotactic radiosurgery, brain metastases, gastrointestinal cancers, radiotherapy