Omitting or reducing radiotherapy in childhood or adolescence Hodgkin Lymphoma

Despite high cure rates, treatment of childhood Hodgkin Lymphoma (HL) is associated with late effects caused mainly by radiotherapy (RT). In the GPOH-HD95 trial of the German Society of Pediatric Oncology and Hematology that was recently published in the Journal of Clinical Oncology, RT was spared in patients achieving a stringently defined complete remission (CR) with chemotherapy and reduced in patients with a good partial remission (PR). Overall, RT-treated patients had superior PFS, but OS was almost identical within each risk-stratified treatment group irrespectively of the use of RT. In the low-risk group, RT could be safely omitted in 20% of patients. In contrast, failure rates were considered unacceptable, when RT was omitted in intermediate or high risk patients achieving a CR. However, salvage therapy was successful, equalizing overall survival between irradiated and non-irradiated patients. Although GPOH-HD95 points out to the omission of RT in selected patients achieving a CR after chemotherapy, especially those in the low-risk group, more than 80% of the patients are still irradiated. Notably, the GPOH-HD95 was not a randomized trial. In conclusion, according to the GPOH-HD95 trial, RT can be safely omitted in pediatric and adolescent patients with low-risk, early stage HL achieving a stringently defined CR after 2 cycles of OPPA or OEPA chemotherapy. RT dose could also be reduced in case of good PR by conventional imaging. However, conventional response assessment is not the optimal means to decide whether RT is needed or not. It is now increasingly recognized that RT can be omitted in many patients with HL without compromising the final outcome and it appears wise to try to stringently limit RT in those patients who really need it. This might be achieved through the use of modern functional imaging (PET/CT). Such efforts are already in progress and results regarding efficacy are awaited relatively soon.