Evaluation of delineating the target volume by radiation therapists in breast cancer patients

Abstract

Aim Breast radiotherapy accounts for a significant workload in radiotherapy departments. In 2015 it became clinical practice at the Netherlands Cancer Institute for radiation therapists (RTTs) to delineate the clinical target volume of the breast tissue (CTVbreast) and in 2017 axilla level I-II (CTVln12) according to a delineation atlas. All RTTs were trained and got individual feedback. The aim of this retrospective study was to investigate the variation between the CTVbreast with or without CTVln12 delineated by a trained group of radiation therapists and the clinical adjusted delineations by the radiation oncologist/physician assistant (RO/PA), in a large group of patients treated between January 2017 and June 2020. Materials and Methods 1012 computer tomography based delineations of CTVbreast and 146 of CTVln12 were collected from January 2017-June 2020. The RTT and RO/PA delineations were compared using the Dice coefficient and the 95th percentile Hausdorff Distance (95%HD). Statistical significance of the differences was tested using a Mann-Whitney test. Results Differences in CTVbreast delineations were small. A median Dice score of 1.00 for all years, where 83% of the patients had a Dice score > 0.99. For CTVln12 the magnitude of edits made by RO/PAs decreased over time, with the Dice increasing from a median of 0.87 in 2017 to 0.90 in 2020 (p = 0.031). The 95%HD decreased from a median of 0.93 cm in 2017 to 0.61 cm in 2020 (p = 0.051). Conclusions This retrospective study shows that trained dedicated RTTs are capable in delivering the same quality delineations as RO/PAs. The low variability supports the increasing role of RTTs in the contouring process, likely making it more time efficient.

Online adaptive MR-guided radiotherapy: Conformity of contour adaptation for prostate cancer, rectal cancer and lymph node oligometastases among radiation therapists and radiation oncologists

“…Following adequate training, RTTs achieve a good concordance with OAR contoured by ROs [6]. Furthermore, evidence is published showing that trained RTTs are capable of delineating pre-treatment targets based on standardized contouring protocols [7,8].…”

Clinical assessment of a novel machine‐learning automated contouring tool for radiotherapy planning

“…The RTT performed the contouring task in accordance with clinical practice at the institution. Previous studies have demonstrated comparable contouring accuracy between RTTs and radiation oncologists (ROs) 27,28 . Datasets were contoured in accordance with the Radiation Therapy Oncology Group (RTOG) contouring consensus 29 .…”

“…Previous studies have demonstrated comparable contouring accuracy between RTTs and radiation oncologists (ROs). 27 , 28 Datasets were contoured in accordance with the Radiation Therapy Oncology Group (RTOG) contouring consensus. 29 The time required to contour each OAR was recorded by the RTT.…”

The Radiation Therapist profession through the lens of new technology: A practice development paper based on the ESTRO Radiation Therapist Workshops

“…To achieve this, the radiation therapist will need to move beyond a task shifting role, to a more consultive role, bringing what is currently considered as advanced practice functioning to the standard practice radiation therapy team. There are many examples of advanced practice radiation therapists demonstrating a high level of autonomy and expert skill in formulating clinical decisions and appropriate patient management [30] , [31] , [32] , [33] . They provide comprehensive supportive care and toxicity management, streamline complex processes, reduce handovers and team interruptions, and improve continuity of care.…”