PET Tumour Segmentation in Head and Neck Cancer: Reproducibility, Reader Dependence and Concordance with CT-Defined Tumour Volume in a 154-Patient Cohort

Purpose

Volumetric PET biomarkers carry substantial prognostic value in head and neck squamous cell carcinoma (HNSCC), yet their clinical implementation is hampered by segmentation heterogeneity. A fundamental and unresolved question is which segmentation method is most suitable for routine clinical use, both for a reader experienced in PET segmentation and for a reader without PET segmentation experience, such as an ENT surgeon or a radiation oncologist. This study addressed this question by assessing the intra- and interobserver reproducibility of four PET segmentation methods in MIM Maestro Software Version 7.4.2, identifying tumour-related determinants of variability, and examining concordance between PET-derived metabolic tumour volume (MTV) and CT-based gross tumour volume (GTV).