This study evaluated survival outcomes and chronic side effects in adult medulloblastoma patients treated with craniospinal irradiation (CSI).

We performed a retrospective analysis of 30 adult medulloblastoma patients treated with postoperative craniospinal radiotherapy (RT; 30–36 Gy) combined with a posterior fossa/tumor bed boost (54 Gy). Kaplan–Meier methods were used to analyze local control (LC) and survival. Long-term quality of life was assessed using the 12-Item Short Form Health Survey (SF-12) questionnaire and the telephone cognitive evaluation (T-Cog) test.

With a median follow-up of 87 months, 10 patients (33.3%) died, 6 due to craniospinal fluid (CSF) recurrence and 4 from distant metastases. The 5‑year local control (LC) and overall survival (OS) rates were 85% and 71%, respectively. Alopecia (64.7%), cognitive decline (41.1%), and ototoxicity (41.1%) were common long-term toxicities, with 5 of 7 ototoxicity cases linked to cisplatin. Secondary tumors occurred in 2 patients. Cognitive impairment was indicated by a mean T‑Cog score of 24, while SF-12 physical and mental health scores were 47.8 and 44.4, both below the cutoff of 50.

Craniospinal RT is a safe and effective treatment for adult patients with medulloblastoma. Future treatment strategies should aim to deintensify therapy by limiting radiation to the local tumor bed in selected low-risk patients and by identifying favorable molecular subgroups for observation after surgery. Advanced techniques and targeted therapies can further reduce toxicity while maintaining strong oncologic outcomes and enhancing quality of life.