Conformal radiotherapy for lung cancer: different delineation of the gross tumor volume (GTV) by radiologists and radiation oncologists

A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging

“…Default visualization parameters were used for lung tumour segmentation by all physicians in accordance with recommendations by Giraud et al (Giraud et al 2002) (−600/1600 HU for lung window, +20/400 HU Figure 1. Methodology flow chart.…”

“…However, as precision improves and prescription dose increases, segmentation error and variability in target volume definition can have greater impact on treatment efficacy. Segmentation-related errors including inter-and intra-observer variability has been demonstrated with respect to lung cancer in 3D image acquisition (Giraud et al 2002, Van de Steene et al 2002. Clinical margins exist to account for internal motion of the tumour volume, setup error, geographic miss of the target volume and irradiation of healthy tissue, however, if variability and segmentation-related error exceeds the clinical margins, patient outcomes and treatment efficacy can be compromised.…”

Variation in Clinical Target Volumes for Post-prostatectomy Patients and Effect on Normal Tissue Complication Probability

“…Previous studies have described differences among multiple contours by different physicians (inter-rater variation) and by the same physician (intra-rater variation) [1][2][3][4] and whether these differences affect clinical outcomes. These studies, however, focused on treating in situ organs rather than 'areas at risk' after resection of the cancerous structure.…”

A Prospective Study to Determine Inter-observer Variability of Gross Tumor Volume with [18F] Fludeoxyglucose-PET/CT Compared to CT Alone in Stage III Non-Small Cell Lung Cancer Using Three-Dimensional Analysis

“…New radiation technologies, including Three Dimensional Conformal Radiotherapy (3DCRT) and Intensity-Modulated Radiation therapy (IMRT), rely on the assumption of accurate and reproducible anatomical target delineation. However, defining GTV purely based on anatomical imaging obtained through CT scans may result in geographical miss and significant interobserver variability [2,3].…”