DIPG-64. Feasibility and early results of radiotherapy, concomitant nimotuzumab and vinorelbine and re-irradiation at progression, for newly diagnosed childhood and adolescence diffuse midline glioma (DMG)

Abstract

Abstract BACKGROUND: The purposes of this trial were evaluating the feasibility, response and PFS/OS of patients receiving upfront radiotherapy and reirradiation at progression with concomitant nimotuzumab/vinorelbine chemotherapy as the standard arm of the ongoing protocol for DIPG. METHODS: Patients aged 2-21 years with not-pretreated DMG (evidence of H3.3K27M mutation at immunohistochemistry) received vinorelbine 20 mg/m2+nimotuzumab 150 mg/m2 weekly for 12 weeks; thereafter every other week until tumor progression or for up to 2 years. Focal photons irradiation was delivered within the 3rd week after first nimotuzumab+vinorelbine administration with a total dose of 54 Gy in 1.8 Gy daily fractions. For local progression re-irradiation was proposed at 19.8 Gy; in case of dissemination craniospinal-irradiation at 36 Gy was adopted. MRI were blindly centrally reviewed at diagnosis and every 12 weeks thereafter. RESULTS: Aggregated preliminary results are available for 20 patients from 4 Italian centers: 12 males, median age 11 years (range 3-17). Median time of observation was 12.5 months; 8 had thalamic/basal ganglia disease, in 5 pons was involved (2 pontobulbar, 3 pontomesencephalic), 6 spinal, 2 cerebellar. 13 patients had only biopsy, the others partial or near-total resection.14 relapsed: 5 locally, 4 with dissemination, 5 with both; 12 died, one was lost at follow-up. Two patients received reirradiation, one of them was irradiated three times without evidence of radionecrosis, still alive at 26 months from diagnosis. Median EFS/OS were 8.3/10.2 months, respectively; EFS/OS at 1 year were 25.8/36.7%. Survival curves between spinal and cerebral locations showed no difference. Patients after partial/near-total resection vs biopsied seemed to have earlier relapses (P 0.017) with EFS at 6 months of 34.3/75.0% respectively. CONCLUSIONS: This is one of the first series of DMG homogeneously and prospectively treated; treatment was feasible. A potential role of reirradiation emerge as in DIPGs.