MS-20 * LEPTOMENINGEAL DISSEMINATION IN RELAPSED ADULT MEDULLOBLASTOMA: PATTERNS OF DISEASE AND ROLE OF INTRATHECAL CHEMOTHERAPY

Abstract

INTRODUCTION: The role of intrathecal chemotherapy (ITc) for relapsed adult medulloblastoma (MB) with leptomeningeal dissemination (LMD) has not been prospectively evaluated. OBJECTIVES: 1. Evaluate clinical, imaging and CSF findings, treatment and outcome of adults developing LMD at MB relapse. 2. Compare outcome of patients treated with ITc vs. other treatments alone (NITc). METHODS: Retrospective review of single institutional experience (1978-11/2004) of adult patients (≥18 yo) was performed. Clinical, imaging, CSF, treatment and outcome data were collected. Time to progression (TTP) and survival from LMD diagnosis were estimated by Kaplan Meier method. Outcome of patients who received ITc vs. NITc was compared by log-rank test. RESULTS: Among 105 patients, we identified 20 patients with imaging and/or CSF diagnosis of LMD at relapse. Thirteen had received craniospinal radiation without chemotherapy at initial diagnosis. Median survival after LMD diagnosis was 9 months (95%CI 7, 12). Two patients died without starting therapy for relapse and were excluded from further analysis. Of the remaining 18, 6 received ITc (3 methotrexate, 2 liposomal cytarabine, 1 topotecan) in addition to systemic chemotherapy, and 1 received spinal radiation. The remaining 12 received systemic chemotherapy (varied regimens), in addition to spinal radiation (2) and radiosurgery to posterior fossa (1). Median TTP from LMD diagnosis was 7 months (95%CI 5, 9) and did not differ between the 2 groups (p = 0.99). Median survival for ITc group was 8 months (95%CI 4, 11), vs. 12 months (95%CI 0-30) for NITc group (p = 0.44). CONCLUSIONS: Prognosis of LMD in relapsed adult MB is poor. More than 50% of patients had not received adjuvant chemotherapy, potentially increasing the risk for treatment failure. Addition of ITc to treatment regimen did not improve outcome in our series. Results need to be confirmed in prospective trials.