Reirradiation treatment of diffuse brain stem tumors in children

Objective: To evaluate the possibility and effectiveness of the reirradiation treatment of diffuse brain stem tumors in children. Material and methods: For 2004-2011 repeated radiation treatment was performed in 20 children with diffuse brain stem tumors. All the children had previously received radiation therapy with irradiation of the tumor in a total dose of 50-55 Gy. The reason for conducting the re-treatment was the resumed tumor growth, proven by clinical and radiological data. The interval between the end of the initial treatment and the beginning of reirradiation ranged from 5 to 32 months, the median interval was 12 months. Reradiation therapy was combined with adjuvant chemotherapy: temozolomide in 10 patients and bevazisumab in three. Total dose of re-irradiation was less than 30 Gy in 10 patients, 31-45 Gy in 9 and 50 Gy in 1. Results: In the process of treatment the condition of the 5 patients, who had radiological signs of the destruction of the tumor, worsened, and therapy was discontinued. Their median survival was 3.5 months. In all others, who had no MRI signs of the tumor destruction, a positive subjective effects were noted in the form of full or partial regression of neurological disorders. In this group 93% survived 6 months from the beginning of the second course, 53% survived one year, 40% - 1.5 years, 20% - 2 years. One patient survived over five-year period, he has lived for 13 years. In one case, 5 months after the re-irradiation at a dose of 50 Gy, symmetric foci of necrosis in the cerebellar hemispheres were identified, combined with persistent tumor growth. Conclusion: Repeated radiation therapy for the regrowth of diffuse brain stem tumors without signs of destruction can improve quality of life and increase survival in most cases.