Clinical impact of hypothalamic-pituitary disorders after conformal radiation therapy for pediatric low-grade glioma or ependymoma.

BACKGROUND: To determine the impact of hypothalamic-pituitary (HP) disorders on health outcomes in children and adolescents who received conformal radiation therapy (RT) for central nervous system tumors. PROCEDURE: Cohort study including 355 patients (age ≤25 years at diagnosis) treated with high-dose (50.4-59.4 Gy) RT using photons for low-grade glioma or ependymoma. Patients (median age, 6.4 years at RT) received systematic endocrine follow-up (median duration, 10.1 years; range, 0.1-19.6). Associations between HP disorders and adverse health outcomes were determined by multivariable analysis. RESULTS: Prevalence was 37.2% for growth hormone deficiency (GHD), 17.7% for gonadotropin deficiency (LH/FSHD), 14.9% for thyroid-stimulating hormone deficiency (TSHD), 10.3% for adrenocorticotropic hormone deficiency (ACTHD), and 12.6% for central precocious puberty (CPP). Hypothalamus mean dose ≥ 36 Gy was associated with higher odds of any deficiency. GHD was associated with short stature (OR 2.77; 95% CI 1.34-5.70), low bone mineral density (OR 3.47; 95% CI 1.16-10.40), and TSHD with dyslipidemia (OR 5.54; 95% CI 1.66-18.52). Patients with ACTHD and CPP had lower intelligence quotient scores, and memory scores were impaired in patients with GHD (P = 0.02). Treatment of GHD was not associated with increased risk for tumor recurrence, secondary tumors, or mortality. CONCLUSIONS: HP disorders occur frequently in patients receiving high-dose RT and are related to physical and neurocognitive well-being. Future studies are needed to assess whether further optimization of endocrine management yields better health outcomes.

Association between hippocampal dose and memory in survivors of childhood or adolescent low-grade glioma: a 10-year neurocognitive longitudinal study.

BACKGROUND: Hippocampal avoidance has been suggested as a strategy to reduce short-term memory decline in adults receiving whole-brain radiation therapy (RT). The purpose of this study was to determine whether the hippocampal dose in children and adolescents undergoing RT for low-grade glioma was associated with memory, as measured by verbal recall. METHODS: Eighty patients aged at least 6 years but less than 21 years with low-grade glioma were treated with RT to 54 Gy on a phase II protocol. Patients underwent age-appropriate cognitive testing at baseline, 6 months posttreatment, yearly through 5 years posttreatment, year 7 or 8, and year 10 posttreatment. Random coefficient models were used to estimate the longitudinal trends in cognitive assessment scores. RESULTS: Median neurocognitive follow-up was 9.8 years. There was a significant decline in short-delay recall (slope = -0.01 standard deviation [SD]/year, P < 0.001), total recall (slope = -0.09 SD/y, P = 0.005), and long-delay recall (slope = -0.01 SD/y, P = 0.002). On multivariate regression, after accounting for hydrocephalus, decline in short-delay recall was associated with the volume of right (slope = -0.001 SD/y, P = 0.019) or left hippocampus (slope = -0.001 SD/y, P = 0.025) receiving 40 Gy (V40 Gy). On univariate regression, decline in total recall was only associated with right hippocampal dosimetry (V40 Gy slope = -0.002, P = 0.025). In children <12 years, on univariate regression, decline in long-delay recall was only associated with right (V40 Gy slope = -0.002, P = 0.013) and left (V40 Gy slope = -0.002, P = 0.014) hippocampal dosimetry. CONCLUSION: In this 10-year longitudinal study, greater hippocampal dose was associated with a greater decline in delayed recall. Such findings might be informative for radiation therapy planning, warranting prospective evaluation.

Investigating the Role of Hypothalamic Tumor Involvement in Sleep and Cognitive Outcomes Among Children Treated for Craniopharyngioma.

OBJECTIVE: Despite excellent survival prognosis, children treated for craniopharyngioma experience significant morbidity. We examined the role of hypothalamic involvement (HI) in excessive daytime sleepiness (EDS) and attention regulation in children enrolled on a Phase II trial of limited surgery and proton therapy. METHODS: Participants completed a sleep evaluation (N = 62) and a continuous performance test (CPT) during functional magnetic resonance imaging (fMRI; n = 29) prior to proton therapy. RESULTS: EDS was identified in 76% of the patients and was significantly related to increased HI extent (p = .04). There was no relationship between CPT performance during fMRI and HI or EDS. Visual examination of group composite fMRI images revealed greater spatial extent of activation in frontal cortical regions in patients with EDS, consistent with a compensatory activation hypothesis. CONCLUSION: Routine screening for sleep problems during therapy is indicated for children with craniopharyngioma, to optimize the timing of interventions and reduce long-term morbidity.