MBCL-35. SALVAGE RADIATION THERAPY FOR PROGRESSIVE AND/OR RELAPSED PEDIATRIC MEDULLOBLASTOMA

Medulloblastoma (MB) has a dismal prognosis after progression or relapse, and there is no standard of care for salvage therapy. Medical records of pediatric patients with progressive/relapsed MB were reviewed for clinical characteristics. We identified 23 patients with recurrent MB with median age at diagnosis of 3.8 years, 14 males (60%). At diagnosis, 16 patients had gross total resection, 1 near total, 5 subtotal, and 1 had biopsy alone. Fifteen patients (66%) had metastatic disease. Tumor histology was classic/nodular in 10, 4 desmoplastic, 8 anaplastic and 1 myogenic. Ten patients (43%) ages < 3 years, were treated with induction chemotherapy followed by high dose chemo and stem cell rescue. Other 13 patients were treated with chemoradiation (11 craniospinal and 2 posterior fossa radiation). Progression free survival after initial treatment was 11 months (range, 3–58 months); 8 patients (34%) had local recurrence, 10 patients (43%) had distant metastasis, 4 patients (17%) had local and distant, and one patient had CSF only recurrence. Salvage therapy was surgery followed by radiation in 12 patients (52%), radiation alone in 3 patients (13%), chemoradiation in 7 patients (30%), and chemotherapy alone in 1 patient. Thirteen patients (56%) received CSI, 6 (26%) received focal and 2 received spinal radiation only. Five year progression free survival and overall survival from the time of relapse were 25% and 45%, respectively. Multidisciplinary care is essential for patients with relapsed MB. Salvage radiation that accounts for the patient’s initial treatment volumes should be considered for these patients.