Measurement of lung tumor volumes using three-dimensional computer planning software

Reproducibility of “Intelligent” Contouring of Gross Tumor Volume in Non–Small-Cell Lung Cancer on PET/CT Images Using a Standardized Visual Method

“…The reasons for avoiding purely automated contouring were described in a recent article (22). Our contouring methodology has gradually been refined after the earlier experience with coregistered PET and CT images (23,24) and experience with contouring using CT alone (20). When our CT contouring method was adapted for use with PET/ CT, it became the responsibility of a dual-trained PET physician/diagnostic radiologist to determine which structures were malignant before contouring.…”

“…An indication of the power and precision of this study to detect differences between observers in GTV assessments was obtained by reviewing data from the study of Bowden et al (20) on interobserver variation in GTV assessments using CT scans. Those data were used in the design of the current study.…”

“…In a previous study of CT-based GTV contouring in NSCLC, we reported that interobserver variation was dramatically reduced by strict contouring guidelines (20). We have developed a rigorous visual PET/CT contouring protocol, based on that experience, that defines standardized settings for window level at the treatment planning workstation, provides all available clinical and imaging information to the person doing the contouring, and uses both PET and CT information in the contouring process.…”

Designing Targets for Elective Nodal Irradiation in Lung Cancer Radiotherapy: A Planning Study

“…On the contrary, it may call for precision in following the recommendation details and a warning to users that strictly following the guidelines may lead to treatment of an elective area that is larger than the traditional area, potentially increasing the lung dose (V20 in this study). It was proved that detailed recommendations may reduce variations in treatment delineation (12). However, we acknowledge that there are no universal recommendations for delineation of targets and that the principle of LNS-CTV delineations must sometimes be adapted to meet local needs.…”

Executive summary of AAPM Report Task Group 113: Guidance for the physics aspects of clinical trials

“…Important technical sources of variation in segmentation include variable window and level settings, the use and sensitivity of auto‐segmentation algorithms to input parameters, and inappropriate margin expansion algorithms. For example, inappropriate window and level parameters can lead to significant bias and errors in volume definition with one study identifying factors leading to variations up to 42% by clinician which were reduced by using a standard protocol 13. Improvements in the consistency of contours are seen when pretreatment reviews of contoured structures are performed by protocol principal investigators.…”