Srinivas Chilukuri

and 16 more

Background: We report demographic profile and our initial experience of treating children and young adults with image guided pencil beam scanning proton beam therapy (PBS-PBT) at our centre. Material and methods: All patients younger than 25 years, consecutively treated with PBT based on a multi-disciplinary tumor board decision were analyzed. Patients were treated under daily on-board kilovoltage x-ray and/or cone beam CT scan guidance. The demographic profile, treatment characteristics and the acute toxicities were reported. Patient and treatment related factors and their association with acute toxicities were analyzed using univariate and multivariate analysis. Results: Forty-seven patients {27 with central nervous system(CNS) and 20 with non-CNS tumors} with a median age of 9 years were evaluated. Most common diagnoses were ependymoma, rhabdomyosarcoma and glioma. Median dose delivered was 54.8CGE(40-70.4) to a median clinical target volume of 175cc (18.7-3083cc) with 34% requiring concurrent chemotherapy(CCT). Acute grade-2 and 3 dermatitis, mucositis, and hematological toxicity was noted in 45% and 2%; 34% and 0%; 38% and 30%; respectively. Grade-2 fatigue was noted in 26%. On univariate analysis, CCT(p=0.009) and cranio-spinal irradiation(p<0.001) were associated with grade-2 or more hematological toxicity in patients with CNS tumors. Among non-CNS tumors, clinical target volume more than 150cc was associated with grade-2 or more fatigue(p=0.017). Conclusions: The demographic pattern of patients treated with PBT at this new and only centre in the region was similar to previously published literature. Image guided PBS-PBT resulted in acceptable acute toxicities both among children with CNS and non-CNS tumors.