Early disc degeneration in radiotherapy-treated childhood brain tumor survivors

Abstract

Background: Childhood brain tumor (BT) survivors have an increased risk of treatment-related late effects, which can reduce health-related quality of life and increase morbidity. With an increasing population of childhood BT survivors, the understanding of the long-term consequences of BT treatment is highlighted. This study aimed to investigate lumbar disc degeneration in magnetic resonance imaging (MRI) in adult survivors of radiotherapy-treated childhood BT compared to age and sex-matched population controls. Methods: In this cross-sectional comparative study, 127 survivors were identified from hospital registries. After a mean follow-up of 20.7 years (range 5–33.1), 67 (mean age 28.4, range 16.2–43.5) survivors were investigated with MRI and compared to 75 sex-matched population-based controls. Evaluated MRI phenotypes included Pfirrmann grading, high-intensity zone-lesions (HIZ), intervertebral disc protrusions, and extrusions. Groups were also compared for known risk factors of intervertebral disc degeneration. Results: Childhood BT survivors had higher Pfirrmann grades than controls at all lumbar levels (all p<0.001). Lumbar disc protrusions at L4-5 (p=0.02) and extrusions at L3-4 (p=0.04), L4-5 (p=0.004), and L5-S1 (p=0.01) were significantly more common in the BT group compared to the control group. BP correlated with a higher degree of IVD degeneration at Th12-L1 (p=0.01), L1-2 (p=0.01), and L3-4 (p=0.03). Survivors with a younger age at diagnosis had significantly lower Pfirrmann grades (p<0.01). Conclusions: Signs of early aging related to tumor treatment can be seen in the intervertebral discs of survivors. Disc degeneration was more severe in children treated in adolescence.