Central nervous system relapse of rhabdomyosarcoma.

PURPOSE: The optimal management of central nervous system (CNS) relapse of rhabdomyosarcoma (RMS) is unclear. We examined diagnosis, management, and outcomes of patients with RMS developing CNS relapse.

METHODS: Records of 23 patients diagnosed with CNS relapse between 1999 and 2016 were reviewed. Median age at presentation of CNS relapse was 15 years (range, 1-34 years). High-risk features at initial presentation were as follows: 16 alveolar patients, 13 Stage IV, and 13 with primary tumor in parameningeal locations.

RESULTS: CNS relapse occurred at a median 12 months (range, 1-23 months) from diagnosis and most common presenting symptoms were headache (n = 9), nausea/vomiting (n = 8), visual difficulty (n = 5), and none (n = 5). Leptomeningeal metastases were detected in 21 patients while only 2 developed parenchymal metastases without leptomeningeal involvement. Fifteen patients received CNS-directed radiation therapy (RT), including craniospinal irradiation to a median 36 Gy (range, 18-36 Gy) and/or whole brain radiotherapy to a median 30 Gy (range, 6-41.4 Gy). Three patients received concurrent chemotherapy. Follow-up magnetic resonance imaging was conducted in 13 patients after RT initiation with 8 demonstrating improvement, 2 with stable disease, and 3 with progression. Twelve patients were tested for reactivity to I-131-labeled monoclonal antibody 8H9, and three tested positive and received at least one intra-Ommaya dose; all three lived >12 months post-CNS relapse. Twenty‐two patients died of CNS disease and one of treatment complications, with metastatic disease at other sites. Median survival post-CNS relapse was 5 months (range, 0.1-49 months).

CONCLUSIONS: The prognosis for patients with RMS developing CNS relapse remains poor. Treatment including CNS-directed RT should be considered and investigation into preventative therapies is warranted.