Gynecologic Interstitial Brachytherapy Curriculum Using a Low-Cost Phantom With Ultrasound Workshop and a Treatment Planning Workshop is Feasible and Effective

Abstract

<h3>Purpose/Objective(s)</h3> There is no standard simulation training geared towards interstitial brachytherapy (IS BT) for gynecologic malignancies. Most residents perform few IS cases during residency. However, IS BT is an integral part of care for locally advanced gynecologic malignancies. We developed and implemented a workshop curriculum for IS BT with: 1) lecture on equipment, workflow, and guidelines, 2) hands-on ultrasound-guided IS BT workshop, and 3) treatment planning workshop. <h3>Materials/Methods</h3> The cost of each gynecologic phantom was approximately $70; phantoms were composed of an acrylic vase cube, rigid PETG tubes, modeling clay, agar, glass microspheres, a custom molded cervix/uterus structure, and a water-filled condom to mimic the bladder. A hands-on ultrasound-guided IS BT workshop was performed with residents in two small groups, where they imaged the gynecologic phantom using a transabdominal ultrasound probe. Participants alternated roles of sonographer or brachytherapist, implanting the phantom using custom stainless-steel needles machined in-house. A second workshop with hands-on treatment planning was performed in planning software using a L-Q spreadsheet with the following objectives: coverage goal of D90, meeting D2cc constraints of bladder and rectum, and minimizing V200 to qualitatively involve a small volume. All residents filled out a pre- and post-survey with subjective (4 demographics; 12 Likert-style) and objective knowledge-based (13) questions about GYN IS-BT. Paired subjective data were compared with the Wilcoxon signed ranks test. Paired objective data were compared with the McNemar's test of paired proportions. All statistical analysis was performed with a 2-sided <i>P</i>-value at the 0.05 significance level. <h3>Results</h3> Four residents had prior IS BT experience. After the workshop, residents reported significantly improved comfort with skills and knowledge regarding GYN IS BT equipment and procedure, evaluating GYN anatomy using ultrasound, and CT Simulation, contouring, and plan review (median pre-session Likert score 2 [1-3] vs post session 3 [3-4], <i>P</i> < 0.05). The overall rate of percent correct items assessing objective radiation oncology knowledge at baseline was 44%, Following completion of the curriculum, the overall percent correct items was 88% (<i>P</i> < 0.0001). All residents "Agree" (2/7) and "Strongly Agree" (5/7) the session was an effective learning experience. Qualitative feedback primarily asked for more time with treatment planning and educational content beforehand. <h3>Conclusion</h3> Residents participating in phantom training with an ultrasound curriculum and a treatment planning session is both feasible and effective. Similar strategies should be considered to enhance and standardize radiation oncology education initiatives for gynecologic IS BT training.