local control of brain metastases after stereotactic radiosurgery: the impact of whole brain radiotherapy and treatment paradigm
Ryan T. Hughes, Paul J. Black, Brandi R. Page, John T. Lucas Jr., Shadi A. Qasem, Kounosuke Watabe, Jimmy Ruiz, Adrian W. Laxton, Stephen B. Tatter, Waldemar Debinski and Michael D. Chan
Purpose: We investigate clinical, pathologic, and treatment paradigm-related factors affecting local control of brain metastases after stereotactic radiosurgery (SRS) with or without whole brain radiotherapy (WBRT).
Methods and materials: Patients with brain metastases treated with SRS alone, before or after WBRT were considered to determine predictors of local failure (LF), time to failure and survival.
Results: Among 137 patients, 411 brain metastases were analyzed. 23% of patients received SRS alone, 51% received WBRT prior to SRS, and 26% received SRS followed by WBRT. LF occurred in 125 metastases: 63% after SRS alone, 20% after WBRT then SRS, and 22% after SRS then WBRT. Median time to local failure was significantly less after SRS alone compared to WBRT then SRS (12.1 v. 22.7 months, p=0.003). Tumor volume was significantly associated with LF (HR:5.2, p<0.001, 95% CI:3.4-7.8).
Conclusions: WBRT+SRS results in reduced LF. Local control was not significantly different after SRS as salvage therapy versus upfront SRS.
Keywords: brain metastasis, stereotactic radiosurgery, whole brain radiotherapy, local failure, treatment paradigm, salvage therapy