Comparison of investigator-delineated gross tumour volumes and quality assurance in pancreatic cancer: Analysis of the on-trial cases for the SCALOP trial

Abstract

Background and purposeWe performed a retrospective central review of tumour outlines in patients undergoing radiotherapy in the SCALOP trial.Materials and methodsThe planning CT scans were reviewed retrospectively by a central review team, and the accuracy of investigators’ GTV (iGTV) and PTV (iPTV) was compared to the trials team-defined gold standard (gsGTV and gsPTV) using the Jaccard Conformity Index (JCI) and Geographical Miss Index (GMI). The prognostic value of JCI and GMI was also assessed. The RT plans were also reviewed against protocol-defined constraints.Results60 patients with diagnostic-quality planning scans were included. The median whole volume JCI for GTV was 0.64 (IQR: 0.43–0.82), and the median GMI was 0.11 (IQR: 0.05–0.22). For PTVs, the median JCI and GMI were 0.80 (IQR: 0.71–0.88) and 0.04 (IQR: 0.02–0.12) respectively. Tumour was completely missed in 1 patient, and ⩾ 50% of the tumour was missed in 3. Patients with JCI for GTV ⩾ 0.7 had 7.12 (95% CIs: 1.83–27.67, p = 0.005) higher odds of progressing by 9 months in multivariate analysis. Major deviations in RT planning were noted in 4.5% of cases.ConclusionsRadiotherapy workshops and real-time central review of contours are required in RT trials of pancreatic cancer.

Quantification of MRI visibility and artifacts at 3T of liquid fiducial marker in a pancreas tissue‐mimicking phantom

“…Delineation of PDAC based on CT images was found to result in large interobserver variations due to poor soft‐tissue contrast . The superior soft‐tissue contrast of magnetic resonance imaging (MRI) may improve the accuracy and precision of tumor detection and delineation for PDAC .…”

“…4 Delineation of PDAC based on CT images was found to result in large interobserver variations due to poor soft-tissue contrast. [5][6][7] The superior soft-tissue contrast of magnetic resonance imaging (MRI) may improve the accuracy and precision of tumor detection and delineation for PDAC. 8 Furthermore, MRI can be repeatedly used in fractionated radiation therapy for characterization of tumor and organ motion and deformation patterns.…”

Stomach Dose–Volume Predicts Acute Gastrointestinal Toxicity in Chemoradiotherapy for Locally Advanced Pancreatic Cancer

“…The details of radiotherapy delivery in the two studies, including radiotherapy trials quality assurance, have been described elsewhere [13,14,19,20]. In SCALOP the Gross Tumour Volume (GTV) was defined as tumour visualised on CT scan with lymph nodes >1 cm diameter, and Planning Target Volume (PTV) was defined as GTV plus 20 mm margin in craniocaudal direction and 15 mm margin otherwise.…”

Addition of MRI for CT-based pancreatic tumor delineation: a feasibility study

“…Furthermore, motion management has been improved with the introduction of 4D computed tomography (CT) [4] and breath holding [5]. One of the remaining major challenges in radiotherapy for pancreatic cancer patients is precise and accurate target volume definition [6][7][8][9].…”