Practice patterns of palliative radiation therapy in paediatric oncology patients amongst an international paediatric research consortium

Abstract

Background/Objectives: Practice of palliative radiotherapy (RT) for paediatric oncology patients is based on extrapolations from adult palliative RT literature. We evaluated the palliative paediatric RT practice patterns to highlight the various regimens employed and to assess opportunity for future palliative RT clinical trials. Design/Methods: Five international institutions with paediatric expertise completed a 122- item survey evaluating patterns of palliative RT for patients < 25 years old from 2010-2015. Two of the five institutions have proton RT capabilities. Palliative RT was defined as treatment with the goal of symptom control or prevention of immediate life-threatening progression. Results: Of 2,358 cases of RT for paediatric patients, 385 cases (16%) were delivered for palliative intent (range 4%-28% across institutions). Anesthesia was required in 12% of cases, most commonly in patients <5 years old. Palliation was required due to metastatic disease in 58% of cases. Common histologies included neuroblastoma (32%), osteosarcoma (17%), leukaemia/lymphoma (16%), rhabdomyosarcoma (12%) Ewing sarcoma (7%), and other (16%). Common indications included pain (40%), intracranial symptoms (24%), respiratory compromise (15%), abdominal distention (7%), and cord compression (6%). Common sites and regimens (total Gy/# fractions) included non-spine bone (38%; 20Gy/4-10fx or 8Gy/1fx), spine (12%; 30Gy/10fx or 20Gy/4fx), abdomen (16%; 30.6Gy/14fx, 30Gy/10fx, 24Gy/16fx, or 20Gy/5fx), head and neck (10%; 30Gy/10fx, 20Gy/5fx, 45Gy/20fx, 25Gy/10fx,), lung/mediastinum (6%; 55.8Gy/31fx, 30Gy/4fx, 20Gy/5- 10fx), primary brain masses (18%;45Gy/25fx, 37.5Gy/15fx, 30Gy/10fx), and brain metastases (5%; targeted/radiosurgery: 35Gy/5fx; whole brain RT: 20Gy/5fx, 30Gy/10fx). Re-irradiation comprised 17% of cases. Common techniques were 3D-CRT (45%), IMRT (26%), and conventional RT (19%). SBRT and proton RT were employed in 25 and 4 cases, respectively, primarily for brain cases. Conclusion: There is significant diversity of practice patterns in paediatric palliative RT. Research characterizing treatment response and toxicity is ongoing. Together, these data will inform the design of forthcoming clinical trials to establish effective regimens and minimize treatment time and toxicity.