The emerging role of radiation therapists in the contouring of organs at risk in radiotherapy: analysis of inter-observer variability with radiation oncologists for the chest and upper abdomen

Abstract

Aims: To compare the contouring of organs at risk (OAR) between a clinical specialist radiation therapist (CSRT) and radiation oncologists (ROs) with different levels of expertise (senior-SRO, junior-JRO, fellow-FRO). Methods: On ten planning computed tomography (CT) image sets of patients undergoing breast radiotherapy (RT), the observers independently contoured the contralateral breast, heart, left anterior descending artery (LAD), oesophagus, kidney, liver, spinal cord, stomach and trachea. The CSRT was instructed by the JRO e SRO. The inter-observer variability of contoured volumes was measured using the Dice similarity coefficient (DSC) (threshold of ≥ 0.7 for good concordance) and the centre of mass distance (CMD). The analysis of variance (ANOVA) was performed and a p-value < 0.01 was considered statistically significant. Results: Good overlaps (DSC > 0.7) were obtained for all OARs, except for LAD (DSC = 0.34 ± 0.17, mean ± standard deviation) and oesophagus (DSC = 0.66 ± 0.06, mean ± SD). The mean CMD < 1 cm was achieved for all the OARs, but spinal cord (CMD = 1.22 cm). By pairing the observers, mean DSC > 0.7 and mean CMD < 1 cm were achieved in all cases. The best overlaps were seen for the pairs JRO-CSRT(DSC = 0.82; CMD = 0.49 cm) and SRO-JRO (DSC = 0.80; CMD = 0.51 cm). Conclusions: Overall, good concordance was found for all the observers. Despite the short training in contouring, CSRT obtained good concordance with his tutor (JRO). Great variability was seen in contouring the LAD, due to its difficult visualization and identification of CT scans without contrast.

Large scale crowdsourced radiotherapy segmentations across a variety of cancer anatomic sites

“…For specific equations for metric calculations please see corresponding Surface Distances Python package documentation 39 . Resultant values are broadly consistent with previous work in breast 40 , sarcoma 41 , H&N 35 , 42 , 43 , GYN 44 , and GI 44 – 46 IOV studies.…”

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

“…In the pretreatment phase organ-at-risk (OAR) delineations are often performed by RTTs [5]. 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].…”

Implementation of web-based open-source radiotherapy delineation software (WORDS) in organs at risk contouring training for newly qualified radiotherapists: quantitative comparison with conventional one-to-one coaching approach

“…Therefore, OARs contouring is considered prerequisites for achieving the optimal curative effect for patients. The emerging role of radiotherapists in dosimetric aspect has led to the need of newly qualified radiotherapists to be equipped with OARs contouring skills [21]. To the best of authors' knowledge, the present study is the first to provide quantitative results to evaluate the effectiveness of WORDS in training OARs contouring skills of newly qualified radiotherapists compared to those trained by conventional one-to-one coaching approach.…”

“…Previous randomized trials have also shown that WORDS is effective alternative to traditional didactic lectures aiming at teaching contouring skills in medical students and residents [16][17][18][19]. Due to the role expansion of radiotherapists in dosimetric aspect [20,21], the effectiveness of WORDS in training newly qualified radiotherapists' OARs contouring skills should also be studied.…”