Online quality control, hyperfractionated radiotherapy alone and reduced boost volume for standard risk medulloblastoma: long-term results of MSFOP 98.

PURPOSE: To determine event free and overall survival, and long-term cognitive sequelae of children with standard-risk medulloblastoma (SRM) treated with hyperfractionated radiotherapy, conformal reduced boost volume without chemotherapy, and online quality assurance. PATIENTS AND METHODS: Forty-eight patients (age 5 to 18 years) were included in the Medulloblastoma-Société Française d'Oncologie Pédiatrique (MSFOP 98) protocol (December 1998 to October 2001). Patients received hyperfractionated radiotherapy (HFRT; 36 Gy, 1 Gy/fraction twice per day) to the craniospinal axis followed by a boost to the tumor bed (1.5-cm margin) to a dose of 68 Gy. Records of craniospinal irradiation were reviewed before treatment started. Neuropsychologic evaluations were done according to the protocol (1, 3, 5, and 7 years after irradiation). Cognitive outcomes were followed longitudinally with full-scale intelligence quotient (FSIQ) obtained with age-adapted Wechsler scales. RESULTS: After a median follow-up of 77.7 months, 6-year overall survival (OS) and event-free survival (EFS) rates for the cohort were 78% (95% CI, 66% to 90%) and 75%, respectively (95% CI, 62% to 87%). Thanks to quality control, 14 major deviations were detected. Annual full scale IQ decline was 2 points over a 6-year period. Predicted change in FSIQ points per year was 2.15 (95% CI, -1.24 to 3.51) with an intercept (ie, predicted FSIQ) of 93.57 at baseline. CONCLUSION: HFRT protocol with conformal reduced boost and online quality control allows excellent long-term OS and EFS in the absence of chemotherapy. In addition, FSIQ drops seem to be less pronounced than previously reported with standard irradiation regimens.

Conformal radiotherapy, reduced boost volume, hyperfractionated radiotherapy, and online quality control in standard-risk medulloblastoma without chemotherapy: results of the French M-SFOP 98 protocol.

PURPOSE: Between December 1998 and October 2001, patients <19 years old were treated for standard-risk medulloblastoma according to the Medulloblastome-Société Française d'Oncologie Pédiatrique 1998 (M-SFOP 98) protocol. Patients received hyperfractionated radiotherapy (36 Gy in 36 fractions) to the craniospinal axis, a boost with conformal therapy restricted to the tumor bed (to a total dose of 68 Gy in 68 fractions), and no chemotherapy. Records of craniospinal irradiation were reviewed before treatment start. RESULTS: A total of 48 patients were considered assessable. With a median follow-up of 45.7 months, the overall survival and progression-free survival rate at 3 years was 89% and 81%, respectively. Fourteen major deviations were detected and eight were corrected. No relapses occurred in the frontal region and none occurred in the posterior fossa outside the boost volume. Nine patients were available for volume calculation without reduction of the volume irradiated. We observed a reduction in the subtentorial volume irradiated to >60 Gy, but a slight increase in the volume irradiated to 40 Gy. No decrease in intelligence was observed in the 22 children tested during the first 2 years. CONCLUSION: This hyperfractionated radiotherapy protocol with a reduced boost volume and without chemotherapy was not associated with early relapses in children. Moreover, intellectual function seemed to be preserved. These results are promising.