ID #707 Exploratory Mapping of Cranial RT Dosimetry to Social–Cognitive Phenotypes in Childhood Brain Tumor Survivors

Abstract

Childhood brain tumor (BT) survivors treated with cranial radiation therapy (RT) frequently experience neurocognitive late effects, yet dose-sensitive neuroanatomical substrates of social–cognitive vulnerability remain uncharacterized. This exploratory study mapped region-specific RT dosimetry to social cognition, white matter integration, and executive/behavioral functioning.

The RT sample included 14 participants (mAge=14.33, SD = 3.47;57.1% male) recruited from Alberta Children’s Hospital’s Long-Term Survivor Clinic. Neuropsychological assessment included the Wechsler Intelligence Scale for Children–Fifth Edition (WISC-V) indices of Working Memory and Processing Speed and the Test for the Evaluation of Emotions and Socialisation (TEEMS). Parent-reports measuring adaptive, executive and socioemotional functioning were also included. Planned diffusion tensor imaging will further characterize dose-sensitive white matter by quantifying diffusion anisotropy. Exploratory associations (Kendall’s τ and Spearman’s ρ) and dose-threshold contrasts (<30Gy vs ≥ 30Gy) were used.

Higher right hippocampal and infratentorial mean doses related to poorer auditory working memory (τ and ρ, ps<.05;τ p< .05;ρ p<.01). Higher left amygdala and bilateral temporal-lobe doses related to poorer simple auditory digit registration (τ/ρ,ps< .05). For social cognition, slower social labeling performance related to left hippocampal and left temporal-lobe dose (τ/ρ, ps≤ .05), bilateral amygdala dose (τ ps< .05;ρ ps< .01), and sella mean dose (p<.05). Emotion recognition also associated with sella dose (ρ p<.05). Higher total dose correlated with poorer cognitive flexibility and attentional control (ps≤.01), and broader social and functional vulnerabilities (ps<.05) via parent-report.

Dose-threshold contrasts (<30 vs ≥ 30Gy) indicated clinically meaningful impairments to rapid emotion labeling among groups that received more radiation for left temporal, amygdalae, hypothalamus, sella, and supratentorial regions while preserved performance was observed in < 30 Gy groups.

Findings implicate hippocampal, temporal, amygdalae, infratentorial, sellar, and supratentorial dose exposure in auditory working-memory and rapid social-judgment with broader executive/adaptive sequelae. These patterns may inform region-sparing RT planning. Dose-sensitive white matter pathways may emerge via diffusion analysis.