Single brain metastasis: Radiosurgery alone compared with radiosurgery plus up-front whole-brain radiotherapy

BACKGROUND: Neurosurgical resection is considered the standard treatment for most patients with a single brain metastasis. However, radiosurgery (RS) is a reasonable alternative. It was demonstrated that whole-brain radiotherapy (WBRT) in addition to RS improves local control of 1-3 brain metastases. Little information is available regarding WBRT in addition to RS for a single lesion. METHODS: Data of 63 patients who received RS alone for a single brain metastasis were retrospectively compared with 39 patients treated with WBRT+RS for local control of the treated metastasis, distant intracerebral control, and survival. Seven additional potential prognostic factors were investigated including age, sex, Karnofsky performance score, tumor type, extracerebral metastases, recursive partitioning analysis (RPA) class, and interval from tumor diagnosis to irradiation. RESULTS: The 1-year local control rates were 49% after RS and 77% after WBRT+RS (P =.040). The 1-year distant control rates were 70% and 90%, respectively (P =.08). The 1-year survival rates were 57% and 61%, respectively (P =.47). On multivariate analysis, improved local control was associated with WBRT+RS (risk ratio [RR], 1.95; P =.033) and interval from tumor diagnosis to irradiation >15 months (RR, 1.88; P =.042). Improved distant control was almost associated with WBRT+RS (RR, 2.24; P =.05) and age (RR, 2.20; P =.05). Improved survival was associated with KPS 90-100 (RR, 1.73; P =.040), no extracerebral metastases (RR, 1.88; P =.013), RPA class 1 (RR, 2.06; P =.005), and interval from tumor diagnosis to irradiation >15 months (RR, 1.98; P =.009). CONCLUSION: The addition of WBRT to RS was associated with improved local control and distant intracerebral control but not survival.