Acute toxicity profile of radiotherapy in 690 children and adolescents: RiSK data

Background and purposeThe “Registry for the evaluation of side effects after radiation in childhood and adolescence” (risk) was introduced to characterize adverse effects of radiotherapy in childhood and adolescence prospectively. The aim of this analysis was to characterize the pattern of acute side effects.Materials and methodsSince 2001, patients receiving radiotherapy in one of the German pediatric therapy trials have been registered in RiSK with detailed information regarding radiation doses to organs at risk and characterization of acute toxicities.ResultsFrom 2001 to May 2009, 690 patients have been characterized for acute toxicity in primary therapy. Acute toxicity ⩾ grade 1 was observed in 506 patients. In patients irradiated in their lung and liver, patients with grade 1 or 2 acute toxicities showed higher organ volumes exposed to radiation doses <20 Gray (Gy) compared to patients without toxicities. For the salivary glands, there was a positive correlation between the acute toxicity grade and the maximum radiation dose to the organ; the lower GI tract showed a similar trend. The impact of different chemotherapy regimens on these acute side effects remains unclear. Age did not have any impact on side effects.ConclusionThis analysis gives a comprehensive overview of the acute toxicities of radiotherapy in children and adolescents. With prolongation of follow-up, detailed analyses regarding late toxicities will be possible with the characterization of dose–volume–effect relationships.