Craniospinal irradiation in children with medulloblastoma in supine position:: Long-term results

Radiotherapy is an essential method of treatment for medulloblastoma, but the surgery is the primary treatment of choice in the disorder mentioned. In this study, a total number of 33 pediatric patients under 15 years (median age 8.7 years) were irradiated post-operatively within January 1997 and March 2005. All tumors were located infratentorially in the posterior fossa. Chemotherapy was administered in 26 patients (78 %). The patients with craniospinal irradiation were placed in supine position and fixed with a vacuum-form body immobilizer and a head mask. Irradiation was delivered using a planned dose 26-30 Gy with standard 1.3-1.8 Gy daily fractions for the craniospinal axis with photon beam (6 MV). The median overall survival for the whole group was 55.3 months. The median disease-free survival was 20.6 months, 8 patients (24 %) died. No statistical difference in survival rate between standard and high-risk patients was shown. No relationship was found between survival and age, sex or the tumor size. Endocrine deficits occurred in 30% (8 patients of the group were hypothyroid, growth retardation occurred in 7 patients). Our therapeutical results (those of overall and disease-free survival) and side-effects of the craniospinal axis irradiation technique in supine position are comparable with the treatment results and technique toxicity in prone position.