Internal target volume defined by contrast-enhanced 4D-CT scan in unresectable pancreatic tumour: Evaluation and reproducibility

We compared customized ITVs obtained with CE-4D-CT imaging (ITV 4D) with a population-based (ITV PBC) in 29 patients (PTs) and evaluated the intra-observer ITV delineation reproducibility in 5 PTs with unresectable pancreatic ductal adenocarcinoma (PDA). The ITV PBC was quite different from the ITV 4D, with under/over estimation of volume. Intra-observer volume delineation variability on CE-4D-CT and on a single-phase CE-CT were similar (27.6% vs 24.9%).