Pediatric Craniospinal Irradiation in a Nigerian Teaching Hospital

Abstract

Purpose/Objective(s): Craniospinal Irradiation (CSI) is standard of care in the treatment of primary CNS tumors with the propensity to seed through the cerebrospinal fluid. Survival rates of patients with these tumors have increased dramatically since the early 1960s because of the advances in treatment and reduction in treatment toxicity experienced. Low/middle-income countries, like Nigeria, continue to experience several barriers to treatment including unavailability of modern radiation treatment facilities. Improved radiation therapy techniques in pediatric CSI aim to improve accurate treatment delivery and reduce acute and long-term toxicity and sequelae. Volumetric Modulated Arc Therapy (VMAT) is a new treatment technique in Nigeria. Although pediatric CSI has been practiced in Nigeria for many years, the use of the VMAT to deliver this treatment is significantly new. We reviewed the first set of patients to undergo CSI at a one-year old cancer center in Nigeria. This series reviews the treatment technique, the progress experienced, dose statistics achieved, treatment toxicities, and current status of the treated patients. Materials/Methods: Five children with histologically diagnosed cancers requiring craniospinal irradiation whose parents consented to the study were recruited and followed through the process of their therapy. All patients had undergone prior surgical resection. Information regarding their clinical history and therapy was noted and analyzed. Doses to the lenses, eyes, optic nerves and chiasm, pituitary gland, brainstem, cochleae, thyroid gland, heart, lungs, liver, kidneys, bowel, and gonads were measured. Results: Diagnoses include intracranial germ cell tumor in 2 patients, medulloblastoma in 1 patient, Pineoblastoma in 1 patient and ependymoma in 1 patient. A dose of 36.0Gy in 1.8Gy daily fractions was prescribed to the entire neuraxis, with a subsequent boost of 18Gy in 10 daily fractions to the primary tumor bed (or posterior fossa) was delivered. Concurrent weekly vincristine was administered when indicated. Toxicity was monitored at weekly review appointments using the CTCAE version 5.0. Acute side effects included: alopecia (100%), hyperpigmentation (80%), nausea and vomiting (60%), headache (80%), leukopenia (100%), neutropenia (100%), and sore throat in 1 patient (20%). All toxicities were grade 1 or 2. No acute grade 3 toxicity occurred in this cohort. At the time of this review, all of the patients are alive and all acute side effects have since resolved completely. Conclusion: Great progress has been made in delivery of CSI in Nigeria demonstrating tolerable acute side effects using VMAT. This series suggests that developing countries, like Nigeria, can safely implement advanced technologies. Additional follow-up will be needed to determine if survival rates and chronic toxicity rates are similar to those of other countries globally.