Associations between patient-reported neurocognition, mood, and fatigue and radiation dose in oropharyngeal cancer survivors.

Abstract

Radiotherapy is standard of care for oropharyngeal cancer (OPC) but it has been associated with neurocognitive issues, fatigue, and mood disturbances. Voxel-based analysis (VBA) was used to correlate dose and late radiotherapy effects on a fine-grained, voxel-level, without pre-defined regions. A multicentre cross-sectional study, including patients from two tertiary radiotherapy centres: Leeds Cancer Centre (Centre A) and The Christie NHS Foundation Trust, Manchester (Centre B). Patient-reported outcomes for cognitive complaints (Medical Outcomes Study Cognitive Functioning Scale), fatigue (Multidimensional Fatigue Inventory), and mood (Profile of Mood States short form) were administered at least 2 years after treatment. VBA using cross-centre validated software, and three publically available reference CTs, was performed on: single centre only subgroups, and one combined cohort. Regions of significance were clinically reviewed and investigated using dose-volume histogram (DVH) analysis. 273 patients treated for OPC (Centre A: 118, Centre B: 155) were included, with significant inter-centre differences observed in age, T-stage, N-stage, and dose/fractionation. Dose to the identified cerebellar region differed between centres, with median equivalent dose in 2 Gy fractions (α/β = 3 Gy) of 6.8 Gy for Centre A and 10.2 Gy for Centre B. Correlations of dose with mood disturbance and fatigue within regions of the right-posterior cerebellum were identified for centre B only. There are potential positive associations between right-posterior cerebellum dose with late mood disturbance and fatigue, including potential dose-effect thresholds and cerebella sensitivity to dose per fraction. Further research is needed to clarify these findings, and to establish causality.