Comparison of investigator-delineated gross XXXX volumes and quality assurance in @entity788 : Analysis of the pretrial benchmark case for the SCALOP trial.

@entity5 @entity788 @entity343 @entity138
BACKGROUND AND PURPOSE: To evaluate the variation in investigator-delineated volumes and assess plans from the radiotherapy trial quality assurance (RTTQA) program of SCALOP, a phase II trial in locally advanced @entity788 . MATERIALS AND METHODS: Participating investigators (n=25) outlined a pre-trial benchmark case as per @entity138 protocol, and the accuracy of investigators' GTV (iGTV) and @entity343 (iPTV) was evaluated, against the trials team-defined gold standard GTV (gsGTV) and @entity343 (gsPTV), using both qualitative and geometric analyses. The median Jaccard Conformity Index (JCI) and Geographical Miss Index (GMI) were calculated. Participating @entity138 centers also submitted a radiotherapy plan for this benchmark case, which was centrally reviewed against protocol-defined constraints. RESULTS: Twenty-five investigator-defined contours were evaluated. The median JCI and GMI of iGTVs were 0.57 (IQR: 0.51-0.65) and 0.26 (IQR: 0.15-0.40). For iPTVs, these were 0.75 (IQR: 0.71-0.79) and 0.14 (IQR: 0.11-0.22) respectively. Qualitative analysis showed largest variation at the @entity5 edges and failure to recognize a peri-pancreatic lymph node. There were no major protocol deviations in @entity138 planning, but three minor @entity343 coverage deviations were identified. . CONCLUSIONS: SCALOP demonstrated considerable variation in iGTV delineation. RTTQA workshops and real-time central review of delineations are needed in future trials.
