Abstract
PURPOSE
To report outcomes of salvage re-irradiation in the multi-modality management of recurrent medulloblastoma.
METHODS
Medical records of all patients with recurrent medulloblastoma treated with curative-intent re-irradiation at a single institution were analyzed.
RESULTS
A total of 24 patients (median age of 14 years) were included. Median time to recurrence was 38 months (range 15-99 months). Of 13 patients with SHH subgroup medulloblastoma, 11 (85%) developed local recurrence while 5 of 7 (71%) group 4 patients developed focal recurrence outside the tumor bed. Neuraxial dissemination was seen in 2 patients each of SHH and group 4, while the lone patient with WNT-pathway experienced leptomeningeal dissemination. Molecular subgrouping was not known in 3 patients. Re-irradiation was focal in 58%, extended-field in 17%, and craniospinal re-irradiation in 25% patients. Median interval from primary course of irradiation was 49 months (range 24-98 months) and median cumulative biologically effective dose (BED) was 117 Gy (range 78-132 Gy). All patients received platinum-based salvage chemotherapy either before or after re-irradiation. At a median follow-up of 16.5 months, the 2-year post-re-irradiation progression-free survival and overall survival was 45% and 61% respectively. Patients with average-risk medulloblastoma at initial diagnosis fared better than high-risk disease, while site of relapse, and molecular subgrouping did not impact upon outcomes after re-irradiation. Two of 16 failures were in-field of re-irradiation indicating excellent local control. One patient developed symptomatic radiation necrosis.
CONCLUSION
Re-irradiation provides excellent local control and encouraging survival outcomes with acceptable toxicity in carefully selected patients with recurrent medulloblastoma.