HG-06: RE-IRRADIATION (RE-RT) FOR CHILDREN WITH RELAPSING DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG): BETTER SURVIVAL AND BETTER TIME

Since 2009 we launched a strategy for children with centrally reviewed MRI DIPG diagnosis. Vinorelbine with nimotuzumab–an anti-EGFR monoclonal antibody-were weekly administered during the delivery of 54 Gy irradiation, 1.8 Gy/fraction daily, and for a total of 12 weeks, thereafter any other week until tumor progression or for two years duration. Since 7/2011 re-RT was offered both in case of local/disseminated progression: for local it consisted of 19.8 G/11 daysfractions; if needed, craniospinal irradiation (CSI) dose was 36 Gy/20 fractions. Of 40 patients treated, 29 had local (24) or disseminated (5) progression and 19 were given local (16) or CS (3) re-irradiation a median 8 months after first radiotherapy (2.5-19 months). Reasons for not re-irradiating the other 10 children were: progression before 7/2011(4), refusal(4), too poor PS(2); progression site were not different in the two groups. Survival after re-irradiation lasted between two weeks-14 months, median 6; a statistically different median OS between the re-irradiated/not-reirradiated children was found, being 16 and 12 months, respectively(P = 0.003). Re-irradiation induced, in 17 radiologically evaluated patients: 9 tumor volume reduction, 3 stable volumes, while 5 had progression; 14 had symptom amelioration and 13 steroid suspension. 8/9 volume reductions were obtained after same response at previous irradiation while one had stable disease after first irradiation. No adverse event occurred. Re-irradiation after progression was a concrete benefit for both OS and quality of patients life with symptom amelioration in 14/19. This option is worth to be offered also in case of disseminated progression.