Background: The standard of care for CNS lymphoma typically includes high dose methotrexate followed by whole brain radiation therapy, but there is an increased risk of neurotoxicity with this regimen. In our institution, we offered stereotactic radiosurgery (SRS) for disease refractory to HD-MTX in a subset of patients. A search of the literature on this modality for CNS lymphoma was also conducted.
Methods: Medical records of six patients who received partial brain radiation therapy for persistent CNS lymphoma were reviewed. SRS was given via 1-3 fractions to doses of 21 or 24 Gy. PubMed, SCOPUS, and Cochrane Library databases were systematically searched for articles reporting on outcomes for CNS lymphoma treated with SRS.
Results: Six patients (eleven lesions) were treated with SRS for CNS lymphomas. Median follow up was 15.6 months (range 3.3-37.8). Median RT dose per lesion was 21 Gy and median time to progression was 12.7 months. Median overall survival was not reached. Four patients had distant intracranial failure with two developing local recurrence. The search strategy yielded 16 studies of which only one was prospective and included a control group. 183 out of 256 evaluated lesions (69%) responded completely to treatment and 13 of 204 patients (6%) recurred within the treatment area at last follow-up. Overall, the treatment was well tolerated.
Conclusion: SRS may provide favorable local control in patients with refractory CNS lymphomas. A prospective trial is warranted to validate the efficacy of such an approach.
Keywords: CNS; Central nervous system lymphoma; Gamma knife; Lymphoma; SRS; Stereotactic radiosurgery.