A Prostate Fossa Contouring Instructional Module: Implementation and Evaluation

Abstract

Purpose/Objective Radiation oncology trainees frequently learn to contour through clinical experience and lectures. A hands-on contouring module was developed to teach delineation of the postoperative prostate clinical target volume (CTV) and improve contouring accuracy. Methods Medical students independently contoured a prostate fossa CTV before and after receiving educational materials and live instruction detailing the RTOG approach to contouring this CTV. Metrics for volume overlap and surface distance (Dice similarity coefficient, Hausdorff distance (HD), and mean distance) determined discordance between student and consensus contours. An evaluation assessed perception of session efficacy (1 = “not at all” to 5 = “extremely”; reported as median[interquartile range]). Non-parametric statistical tests were used. Results Twenty-four students at two institutions completed the module, and 21 completed the evaluation (88% response). The content was rated as “quite” important (4[3.5–5]). The module improved comfort contouring a prostate fossa (pre 1[1–2] vs. post 4[3–4], p<.01), ability to find references (pre 2[1–3] vs. post 4[3.5–4], p<0.01), knowledge of CT prostate/pelvis anatomy (pre 2[1.5–3] vs. post 3[3–4], p<.01), and ability to use contouring software tools (pre 2[2–3.5] vs. post 3[3–4], p=.01). After intervention, mean DSC increased (0.29 to 0.68, p<0.01) and HD and mean distance both decreased, respectively (42.8 to 30.0, p<.01; 11.5 to 1.9, p<.01). Conclusions A hands-on module to teach CTV delineation to medical students was developed and implemented. Student and expert contours exhibited near “excellent agreement” (as defined in the literature) after intervention. Additional modules to teach target delineation to all educational levels can be developed using this model.

Clinical relevance of metal artefact reduction in computed tomography (iMAR) in the pelvic and head and neck region: Multi‐institutional contouring study of gross tumour volumes and organs at risk on clinical cases

“…It provides values between 0 and 1, where 0 represents no intersection and 1 reflects clear overlap of structures A and B. In the literature, a DSC > 0.7 is commonly reported to indicate an excellent match . The DSC parameter not only considers absolute volumes but also local positions of two (A and B) compared volumes.…”

“…In the literature, a DSC > 0.7 is commonly reported to indicate an excellent match. 24 The DSC parameter not only considers absolute volumes but also local positions of two (A and B) compared volumes. Single absolute volumes of two structures are independent of the location.…”

Comparison of Computed Tomography– and Magnetic Resonance Imaging–based Clinical Target Volume Contours at Brachytherapy for Cervical Cancer

“…The CT HR-CTV and MRI HR-CTV were then superimposed on one another, and the Dice coefficient of similarity (DC) was calculated using the formula $DCfalse(A,Bfalse)=\frac{2|A\cap B|}{\left|A\right|+\left|B\right|}$, where A represents the CT HR-CTV contour, B represents the MRI HR-CTV contour, and ∩ represents the overlap of the two contours. DC has been used in previous contouring studies to quantify the extent of overlap of two volumes (13, 17, 18); DC=1 represents perfect overlap, while DC=0 represents no overlap.…”

Prospective International Pilot Study Evaluating the Efficacy of a Self-Guided Contouring Teaching Module With Integrated Feedback for Transitioning From 2D to 3D Treatment Planning

“…National and international cooperative groups and organizations have developed contouring atlases and seminars to help improve accuracy and standardize contouring. 1,2,12,13 Contouring atlases are useful but do not provide their users active feedback. Some contouring training programs provide contouring feedback to users, 14,15 and others do not.…”

“…3 In addition, contouring feedback may be given at the end of the training module without additional examination to assess for improvement after feedback. 13 It is a well-known concept in education that feedback is critical to more effective learning. 16,17 Training sessions that included feedback have shown good success.…”