Treatment‐related calvarial lesions in pediatric brain tumor survivors

Abstract

Background: Despite improved survival, many pediatric brain tumor survivors receiving radiation therapy (RT) experience late effects. Procedure:To study calvarial lesions in this population, we retrospectively reviewed records of patients undergoing neurosurgical evaluation for calvarial bone lesions detected in posttreatment follow-up imaging at St. Jude Children's Research Hospital. Primary tumor diagnosis, treatment, imaging, surgical intervention, and histopathology from patients with radiographic evidence of lesions followed for ≥2 years post-RT were studied.Results: For 17 patients with 18 index lesions, median time to lesion manifestation was 2.34 years.Medulloblastoma patients developed lesions at a shorter interval from RT than ependymoma patients (P = .05). Twelve of 14 lesions requiring surgery were benign fibro-osseous or sclerotic.Two malignant lesions distinct from the primary tumor had genetic predisposition to malignancy. Conclusion:Most calvarial lesions arising post-RT are benign and fibro-osseous. Serial imaging is recommended, and high index of suspicion for malignant lesions is warranted for patients genetically predisposed to cancer. K E Y W O R D Scalvarial lesion, pediatric brain tumor, radiation therapy workup for primary CNS tumors. Records from patients with radiographic evidence of new calvarial lesions referred to the neurosurgical service for lesion evaluation were studied for primary CNS tumor diagnosis, treatment, and nuclear imaging. Date and nature of surgical intervention for calvarial lesions, follow-up imaging, and histopathology reports were collected. Diagnosis date of calvarial lesions was when they were first clearly defined in the radiology report. Children with lesions were periodically imaged, primarily by brain magnetic resonance imaging (MRI) every 2-3 months or as required by the treating physician. This study was approved by institutional review boards of St.Jude and Le Bonheur Children's Hospital.