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A single-institution review of long-term outcomes and factors affecting local control (LC) following radiotherapy for non-metastatic medulloblastoma.From 1963 to 2008, 50 children (median age, 7.3 years; range 1.2-18.5) with stage M0 medulloblastoma were treated with radiotherapy; half underwent a gross total resection (no visible residual tumor) or near-total resection (1.5 cm(3) of gross disease remaining after resection). Median craniospinal dose was 28.8 Gy (range 21.8-38.4 Gy). Median total dose to the posterior fossa was 54.3 Gy (range 42.4-64.8 Gy). Eighteen patients (36%) received chemotherapy as part of multimodality management, including 11 who received concurrent chemotherapy.Median follow-up was 15.7 years (range 0.3-44.4 years) for all patients and 26.6 years (range 7.3-44.4 years) for living patients. The 10-year overall survival, cancer-specific survival, and progression-free survival rates were 65%, 65%, and 69%. The 10-year LC rate was 84% and did not significantly change across eras. Four percent of patients experienced local progression five years after treatment. On univariate analysis, chemotherapy and overall duration of radiotherapy ≤ 45 days were associated with improved LC. Patients receiving chemotherapy had a 10-year 100% LC rate versus 76% in patients not receiving chemotherapy (p = 0.0454). When overall radiotherapy treatment lasted ≤ 45 days, patients experienced a superior 95% 10-year LC rate (vs. 73% in patients treated45 days; p = 0.0419). Three patients (6%) died from treatment complications, including radionecrosis/cerebellar degeneration, severe cerebral edema leading to herniation, and secondary malignancy.While we cannot draw definitive conclusions given the retrospective nature of our study, our long-term data suggest that reductions in craniospinal dose and boost target volume to reduce toxicity have not compromised disease control in the modern era. Our data also support analyses that implicate duration of radiotherapy, rather than interval between surgery and radiotherapy, as a factor in LC. Chemotherapy in multimodality management of medulloblastoma may have an underappreciated role in improving LC rates.

The purpose of this study is to review late toxicity following craniospinal radiation for early-stage medulloblastoma.Between 1963 and 2008, 53 children with stage M0 (n = 50) or M1 (n = 3) medulloblastoma were treated at our institution. The median age at diagnosis was 7.1 years (range 1.2-18.5). The median craniospinal irradiation (CSI) dose was 28.8 Gy (range 21.8-38.4). The median total dose, including boost, was 54 Gy (range 42.4-64.8 Gy). Since 1963, the CSI dose has been incrementally lowered and the high-risk boost volume reduced. Twenty-one patients (40%) received chemotherapy in their initial management, including 12 who received concurrent chemotherapy. Late sequelae were evaluated by analyzing medical records and conducting phone interviews with surviving patients and/or care-takers. Complications were graded using the NCI Common Terminology Criteria for Adverse Events, version 4.0.The median follow-up for all patients was 15.4 years (range 0.4-44.4) and for living patients it was 24 years (range 5.6-44.4). The overall survival, cause-specific survival, and progression-free survival rates at 10 years were 67%, 67%, and 71%, respectively. Sixteen patients (41% of patients who survived five years or more) developed grade 3 + toxicity; 15 of these 16 patients received a CSI dose23.4 Gy. The most common grade 3 + toxicities for long-term survivors are hearing impairment requiring intervention (20.5%) and cognitive impairment (18%) prohibiting independent living. Four patients developed secondary (non-skin) malignancies, including three meningiomas, one rhabdomyosarcoma, and one glioblastoma multiforme. Three patients (5.6%) died from treatment complications, including radionecrosis, severe cerebral edema, and fatal secondary malignancy.Ongoing institutional and cooperative group efforts to minimize radiation exposure are justified given the high rate of serious toxicity observed in our long-term survivors. Follow-up through long-term multidisciplinary clinics is important and warranted for all patients exposed to radiotherapy in childhood.