Quality assurance of the EORTC radiotherapy trial 22931 for head and neck carcinomas: the dummy run

The Impact of Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) Definition on the Total Accuracy in Radiotherapy

“…By far the widest range in interobserver variations, however, was observed in the delineations of head and neck tumors, esophageal and lung carcinomas [6,27,34,36,39,40]. The size of the largest inserted GTVs was up to more than eightfold the size of the smallest volumes.…”

“…One major factor attributing to the observed interobserver variations was claimed to be the lack of exact advice for outlining the target volume [39]. However, even identical descriptions of the task to be performed did not lead to congruent volumes.…”

“…Above all, explicit instructions are necessary for the delineation of GTVs, CTVs and PTVs. Detailed advice is particularly important for multicenter studies to keep interobserver variations as low as possible [33,39]. For a consistent contouring of GTVs and CTVs, among others the assessment of edema and contrast enhancement, and the specification of the size of lymph nodes that should be judged as pathologic have to be part of instructions for target volume delineation.…”

Improving radiotherapy quality assurance in clinical trials: assessment of target volume delineation of the pre-accrual benchmark case

“…These include writing of a clear protocol [8,9], access to an outlining atlas [10], outlining of pretrial benchmark cases, review of clinical cases from each centre ("dummy runs") [3,[11][12][13][14] and workshop attendance [14,15]. Access to a protocol and an outlining atlas has been shown to improve consistency in outlining prostate [16] and rectal cancers, respectively [10,17].…”

“…These can represent the variation in volume and spatial relationship in a single metric, which may have distinct advantages. These include the Jaccard conformity index (JCI) [35], geographical miss index (GMI) [36], discordance index (DI) [11], mean distance to conformity (MDC) [37] and the k statistic [38]. For further details, the reader is referred to a review by Hanna et al [35] and a recent publication by Fotina et al [39].…”