Pancreas, Muscle, and Subcutaneous Fat Atrophy in Patients Undergoing Radiation for Neuroblastoma

Radiation therapy (RT) is part of standard-of-care therapy in high-risk neuroblastoma (HR-NBL) but can significantly affect nearby tissue. The objectives of this study were (1) to characterize changes in pancreas volume after RT and (2) to characterize changes in body composition, including body weight percentile, subcutaneous fat area, and total psoas muscle area (tPMA), after RT in children with abdominal HR-NBL.

This retrospective study included patients aged 0-17 years old with HR-NBL cared for at a quaternary pediatric hospital (January 2012-December 2022). Pre- to post-RT differences in outcomes were compared using paired t-test, then modeled using linear regression to adjust for covariates and additional variables.

Fifty patients (median age 3 [IQR 2], 56% male) met the inclusion criteria. Median days from end of radiation to first post-radiation imaging was 15.5 days (IQR 14). Pre- to post-RT, mean pancreatic volume decreased significantly (from 16,731 mm³ [SD 7659] to 14,288 mm³ [SD 7418], p < 0.001) and patient body weight percentile declined significantly (48.4-44.9, p = 0.016), although neither was linearly associated with radiation dose. There were non-significant decreases in subcutaneous fat area standardized to height (38.6-36.9 cm²/m², p = 0.41) and in tPMA z-scores (-1.56 to -2.09, p = 0.26).

Patients undergoing RT for abdominal HR-NBL experienced significant pancreatic volume loss. This may place them at risk for pancreatic insufficiency. Patients also had significant decreases in weight percentile with corresponding non-significant decreases in subcutaneous fat and psoas muscle area. Further research is needed to characterize the association of these findings with pancreatic function and nutritional status.