Spectrum of neuroimaging findings post-proton beam therapy in a large pediatric cohort.

PURPOSE: Proton beam therapy (PBT) is now well established for the treatment of certain pediatric brain tumors. The intrinsic properties of PBT are known to reduce long-term negative effects of photon radiotherapy (PRT). To better understand the intracranial effects of PBT, we analyzed the longitudinal imaging changes in a cohort of children with brain tumors treated by PBT with clinical and radiotherapy dose correlations. MATERIALS AND METHODS: Retrospective imaging review of 46 patients from our hospital with brain tumors treated by PBT. The imaging findings were correlated with clinical and dose parameters. RESULTS: Imaging changes were assessed by reviewing serial magnetic resonance imaging (MRI) scans following PBT over a follow-up period ranging from 1 month to 7 years. Imaging changes were observed in 23 patients undergoing PBT and categorized as pseudoprogression (10 patients, 43%), white matter changes (6 patients, 23%), parenchymal atrophy (6 patients, 23%), and cerebral large vessel arteriopathy (5 patients, 25%). Three patients had more than one type of imaging change. Clinical symptoms attributable to PBT were observed in 13 (28%) patients. CONCLUSION: In accordance with published literature, we found evidence of varied intracranial imaging changes in pediatric brain tumor patients treated with PBT. There was a higher incidence (10%) of large vessel cerebral arteriopathy in our cohort than previously described in the literature. Twenty-eight percent of patients had clinical sequelae as a result of these changes, particularly in the large vessel arteriopathy subgroup, arguing the need for angiographic and perfusion surveillance to pre-empt any morbidities and offer potential neuro-protection.

Superior mesenteric artery syndrome (Wilkie's syndrome) complicating recovery from posterior fossa surgery in a child--a rare phenomenon.

INTRODUCTION: Superior mesenteric artery or Wilkie's syndrome is defined as compression of the third part of duodenum by superior mesenteric artery. It has not been previously reported in children after neurosurgical procedures. CLINICAL HISTORY: We present the case of a child who had persistent vomiting after surgery for posterior fossa astrocytoma complicated by low pressure hydrocephalus. CONCLUSION: Despite eventual hydrocephalus control, vomiting persisted, and she was diagnosed with superior mesenteric artery syndrome, this being confirmed radiologically and settled with appropriate nutritional management.