MATERIAL AND METHODS: A retrospective study of all children with DIPG treated with RT3 or RT4 at a single institution was performed. Medical records were reviewed, and composite dosimetry across all delivered courses of RT was reconstructed. All patients received conventionally fractionated photon RT at 1.8-2 Gy per day, with RT3 or RT4 dose prescriptions ranging 18-21.6 Gy in 10-12 fractions to the brainstem.
RESULTS: Five patients were identified; four received three courses of RT while one received four to the brainstem. Median survival from the last course of radiation to death was 4 months; median survival from the first course of RT was 26 months. The median cumulative brainstem D0.03cc for all courses of radiation was 104 Gy (interquartile range: 102-112 Gy). The median time from RT2 to RT3 was 8 months, with partial neurologic recovery (80%) or stable symptoms (20%) after RT3. Radiological appearance of tumor or brainstem necrosis was reported in two patients after RT3 (40%).
CONCLUSIONS: A third course of RT may be carefully considered as a treatment option for selected children with recurrent DIPG to provide palliation of neurologic symptoms.