The Scalop Trial Plan Assessment Form (Paf) As A Tool For Radiation Therapy Trials Quality Assurance (Rttqa)

SCALOP, a randomized Phase II multicenter trial, compared gemcitabine-chemoradiation (CRT) and capecitabine-CRT following induction chemotherapy in locally advanced pancreatic cancer (LAPC); 74 patients were randomized to a CRT arm. A prospective RTTQA program to ensure protocol compliance and high quality RT delivery involved: (1) RT trial protocol including radiologist outlined example images; (2) Centrally reviewed benchmark case for outlining and planning; (3) Real time, on-trial assessment of RT planning compliance for every patient using a trial specific PAF, to allow all planning data to be compared against protocol standards. The aims of this study were to evaluate the feasibility and usefulness of this PAF tool. Investigators returned benchmark cases and completed PAF along with structure and dose files in DICOM format. Central review utilized VODCA software (Visualisation and Organisation of Data for Cancer Analysis), able to open cases from various Treatment Planning Systems. Feedback to Investigators on GTV delineation, correct completion of PAF and protocol compliance was via a template report. Dose to organs at risk (OARs) and PTV reported on the PAF were compared with values in VODCA to determine correct completion of the PAF and also protocol adherence. For on-trial RTTQA, centers faxed the PAF to the WCTU office after RT planning but prior to initiation of RT. The RT plan was collected for future analysis but was not reviewed in real time. Benchmark case GTV outlining variation has been previously reported. In all cases OARs and PTV dose constraints were met (90% of PTV receiving 100% of the dose in all cases). The accuracy of PAF completion compared to VODCA values was very high with only 4 errors (>5% difference) from 6 constraints in 21 cases (0.03%); 2 cases the % dose not actual dose (Gy) was entered for spinal cord PRV and 2 other cases the dose to the kidney varied by more than 5% (7.7%, 6.8%, respectively). 4 centers named the ipsilateral kidney incorrectly. On-trial PAF review indicated that the OAR dose-constraints were met in all cases. Pre-defined minor variations were: volume of PTV receiving >95% of prescription dose was <99% in 6 cases (lowest value 95.3%) and ICRU max >107% (1 case: 107.9%). Comparison of PAF and VODCA values for on-trial patients is ongoing. Review of outlining, planning and completion of the PAF for the benchmark case facilitated real-time review for on-trial RTQA in this first multi-center trial of CRT in LAPC in the UK. PAF is an effective simple tool to evaluate RT compliance and contributed to observed and reassuring levels of protocol compliance.