ESTRO 2024 - Abstract Book

S5852

RTT - Education, training, advanced practice and role developments

ESTRO 2024

3132

Digital Poster

Contouring for student radiation therapists: when, why, and how?

Theresa O'Donovan, Annemarie Devine

University College Cork, Medical Imaging and Radiation Therapy, School of Medicine, Cork, Ireland

Purpose/Objective:

The delivery of safe and effective radiation therapy (RT) relies on accurate delineation of targets and organs at risk (OARs). However, this process is a potential source of interobserver variation 1 . Contouring OARs is a critical skill required of radiation therapists (RTTs) 2 . Contouring is included as a core component of a module “Treatment planning, localisation and verification” (TPLV) within the pre-registration curriculum for student RTTs. Optimal training in terms of case mix, time contouring, and appropriate assessment or timepoints of assessment of this competence have yet to be defined. The aim of the study was to design a program of learning and assessment to improve students’ knowledge and skills of contouring.

Material/Methods:

In the TPLV module students were provided with a range of educational interventions including didactic lectures, expert contouring demonstrations on a treatment planning system (Monaco), access to consensus contouring guidelines and access to two web-based platforms (eContour and Primal Pictures). Following these interventions students participated in practical workshops using a software program (ProKnow®) to learn, practice, study, and improve delineating critical anatomic structures on CT (Computed Tomography) images in the pelvis region. ProKnow® provided feedback after each iteration in terms of Dice similarity coefficients (DC) and StructSure™ scores (US Patent 8,081,813) in relation to the quantitative analysis of contouring accuracy vs. gold standards. Students submitted one set of contours (Large Bowel, Bladder, Rectum, Sigmoid and Penile Bulb) immediately following educational interventions, (T1) and again at a second timepoint (T2) four months later (at the end of a six-week block of clinical placement). Students were also invited to provide qualitative feedback on the learning experience via MS Forms.

Results:

Eight students completed the learning experience (n=8). Quantitative results (Dice similarity coefficients and StructSure™ scores) at T1 and T2 are displayed in Table 1. In relation to the Dice similarity coefficients there was an improvement in mean scores in all OARS contoured except bladder between the two timepoints (T1 and T2). The increase in mean scores reached statistical significance for large bowel (p= 0.017), rectum (p= 0.008), sigmoid (p= 0.011) and penile bulb (p= 0.007). In relation to the StructSure™ scores there was greater variation seen in large bowel, rectum, and penile bulb at T1 with larger ranges and interquartile range (IQR) in the contours submitted. However, there was an improvement in mean scores in all OARS contoured at T2. The increase in mean scores did not reach statistical significance.