Practice Patterns of Palliative Radiation Therapy in Pediatric Oncology Patients Amongst an International Pediatric Research Consortium

Abstract

Little evidence guides the delivery of palliative radiation therapy (RT) for pediatric oncology patients, with practice based on extrapolations from adult palliative RT literature. We evaluated the practice patterns of pediatric palliative RT through an international pediatric consortium to highlight the various regimens employed and to assess opportunity for future palliative RT clinical trials across the consortium. Five international institutions with dedicated pediatric expertise completed a 122-item survey evaluating patterns of palliative RT for patients < 25 years old from 2010-2015. Two of the 5 institutions have proton RT capabilities. Palliative RT was defined as treatment with the goal of symptom control or prevention of immediate life-threatening progression. Of 2,358 cases of RT for pediatric 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%), leukemia/lymphoma (16%), rhabdomyosarcoma (12%) Ewing sarcoma (7%), and other histologies (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%; 20 Gy/4-10 fx or 8Gy/1fx), spine (12%; 30 Gy/10 fx or 20 Gy/4 fx), abdomen (16%; 30.6 Gy/14 fx, 30Gy/10 fx, 24 Gy/16 fx, or 20 Gy/5 fx), head and neck (10%; 30 Gy/10 fx, 20 Gy/5 fx, 45 Gy/20 fx, 25 Gy/10 fx,), lung/mediastinum (6%; 55.8 Gy/31 fx, 30 Gy/4 fx, 20 Gy/5-10 fx), primary brain masses (18%;45 Gy/25 fx, 37.5 Gy/15 fx, 30 Gy/10 fx), and brain metastases (5%; targeted/radiosurgery: 35 Gy/5 fx; whole brain RT: 20 Gy/5 fx, 30 Gy/10 fx). Re-irradiation comprised 17% of cases, often in progressive primary brain tumors. 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. Physician-reported barriers to palliative RT included concern for toxicity, referring provider’s willingness to consider RT, or lack of other providers’ knowledge of indications. Cost and insurance authorization were either never or rarely a barrier. Palliative RT is commonly used in pediatric oncology patients. However, there is significant diversity of practice patterns with no clear standard approach. Research to characterize response and toxicity to treatment is ongoing. Together, these data will inform the design of forthcoming clinical trials to establish effective regimens that minimize treatment time and toxicity.