Abstract Background Diffuse intrinsic pontine glioma (DIPG) is a typically fatal brainstem tumor, with progression commonly occurring within several months after standard radiotherapy. Palliative re-irradiation (reRT) has shown symptomatic benefit in retrospective series; however, prospective data using hypofractionated regimens are limited. This study prospectively evaluated the tolerability of hypofractionated reRT in patients with progressive DIPG. Methods This study was performed at University of Cincinnati/Cincinnati Children’s Hospital Medical Center and enrolled progressive DIPG patients who previously received definitive radiotherapy (≥54 Gy) at least 6 months prior to enrollment. 15 Gy in 3 fractions of hypofractionated reRT was given twice weekly using intensity-modulated radiation therapy. The primary endpoint was tolerability, defined as completion of therapy without serious adverse events (SAEs) attributable to reRT. Results Five patients were enrolled (median age:4.8 years; range 3.2-10 years) and completed reRT without dose reductions or treatment discontinuation. ReRT was given at a mean of 12.3 months (median 12.9 mo., range 9.4-14.7 mo.) from diagnosis and a mean of 9.5 months from the end of initial radiation (median 10.1 mo., 7.6-10.3 mo.). Treatment was generally well tolerated with grade 1-2 adverse events most commonly neurologic, gastrointestinal, and ophthalmologic in nature (Table 1). Four grade ≥3 toxicities occurred, including gait disturbance/ ataxia, aphonia, and agitation. No grade 4–5 treatment-related toxicities were observed. All deaths (n = 5)were attributable to disease progression. No unexpected radiation-related AEs were seen. Mean overall survival from diagnosis was 17.4 months (median 16.1 mo., range 14.2-22.5 mo.) with mean survival from reRT of 4.9 months (median 5 mo., range 1.7-7.8 mo.) Conclusions Hypofractionated re-irradiation of 15 Gy in three fractions was feasible and reasonably well tolerated in this small cohort of patients with progressive DIPG. Further analysis of imaging characteristics and longer-term symptom control is pending.
Smiley et al. (Tue,) studied this question.