Stereotactic Radiosurgery in the Treatment of Recurrent CNS Lymphoma

Abstract

Background: Central nervous system lymphoma (CNSL) is typically treated with chemotherapy and external beam radiation therapy (EBRT). Optimal management of recurrent CNSL is poorly defined.

Objective: We aim to determine the effectiveness of stereotactic radiosurgery in the treatment of recurrent CNSL.

Methods: We performed a retrospective analysis of patients having stereotactic radiosurgery (SRS) for recurrent intracranial CNSL between 1999 and 2011.

Results: Fourteen patients (20 tumors) underwent SRS. The median patient age was 71 years (range, 18-82 years). Seven patients (50%) had primary CNSL. All had received prior chemotherapy, and nine patients (64%) had undergone prior whole brain radiotherapy (WBRT) with a median dose of 40 Gy in 25 fractions. The median preoperative Karnofsky Performance Score was 80. The median tumor volume was 6.7 cm(3) (range, 0.5-37.7); the median margin dose was 15.5 Gy (range, 10-18). Eleven patients (79%) had tumor regression (n = 11) shown on MRI after SRS. The median overall survival after SRS was 9.5 months. No patient had a major radiation-related complication.

Conclusion: Stereotactic radiosurgery for patients with recurrent CNSL is well tolerated and has a high rate of radiographic response. A marginal dose of 15.5 Gy or greater, a Karnofsky score of 80 or greater, and the absence of pre-SRS WBRT were associated with significantly longer overall survival. Stereotactic radiosurgery may be beneficial as an initial salvage therapy in the treatment of recurrent CNSL for properly selected patients.

Keywords: Gamma Knife; Primary CNS lymphoma; Radiosurgery; Secondary CNS lymphoma.