Prognostic role of PET/CT volumetric parameters in paediatric Hodgkin lymphoma: A systematic review and expert recommendations from the International SEARCH for CAYAHL Group

In adults with classic Hodgkin lymphoma (cHL), metabolic tumour volume (MTV) is valuable for risk stratification. This systematic review explored the role of volumetric parameters in children, adolescents and young adults (CAYA) with cHL. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. Five databases were searched on 16 October 2024. Eligible studies were peer-reviewed manuscripts, written in English, published since database inception that included patients ≤21 years of age with a diagnosis of cHL treated with chemotherapy ± radiotherapy with a baseline ¹⁸F-Fluorodeoxyglucose (F-FDG) PET/CT scan for MTV quantification. The search strategy identified 3669 studies, of which 35 were eligible for inclusion. Fifteen studies (43%) evaluated a cohort exclusively ≤21 years of age. All eight studies that explored the association of baseline PET parameters with known risk factors identified a significant correlation. Nine of 12 papers (75%) demonstrated a statistically significant correlation with disease response to therapy on PET/CT. Fifteen of 20 papers (75%) demonstrated an independent statistically significant correlation with clinical outcomes. In the CAYAHL population, volumetric PET parameters are valuable for risk stratification despite heterogeneity in results. Future harmonization of the segmentation approach will facilitate incorporation of MTV into clinical practice.