Vienna, Austria

ESTRO 2023

Session Item

RTT treatment planning, OAR and target definitions
9006
Poster (Digital)
RTT
The emerging role of radiation therapists in contouring organs at risk for rectal cancer.
Poonam Negi, India
PO-2340

Abstract

The emerging role of radiation therapists in contouring organs at risk for rectal cancer.
Authors:

Poonam Negi1, Rajesh Thigle1, Jeevanshu Jain2, Shaktivel Mani3, Shivakumar Gudi4, Rahul Krishnatry4, Reena Engineer4

1ACTREC, Tata Memorial Center, Radiation Oncology, Navi Mumbai, India; 2ACTREC, Tata Memorial Center, Medical Physics, Navi Mumbai, India; 3Tata Memorial Hospital, Radiation Oncology, Mumbai, India; 4Tata Memorial Center, Radiation Oncology, Mumbai, India

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Purpose or Objective

To compare the contours of organs at risk (OAR) by radiation therapy technologist (RTT) and radiation oncologist in training/residents (ROr) for rectal cancer patients.

Material and Methods

The RTT (PN, RT) and ROr (SM) were trained to contour OARs (bladder, bowel, left and right femur) as per the national rectal cancer guideline, UK, 2021. Both groups contoured each OAR for 28 patients independently on planning CTs of previously treated rectal cancer patients. The volume and the dimensions (length, width, depth) in the plane of the largest dimension in the 3D view on the planning system were documented for each of the OAR of by RTT and ROr respectively. The two sets were reviewed by a senior radiation oncologist (Ros; SG, RK, RE) for visual acceptability. The mean volumes and other dimensions for each OAR in the two sets were compared using analysis of variance (ANOVA) where p-value < 0.05 were considered statistically significant.

Results

All contours of OAR for RTT and ROr were found appropriate by each of the Ros independently. There was no significant difference in mean  SD volume determined by ROr versus (Vs.) RTT for bladder, small bowel, left femur and right femur [355.39 ±169.22 Vs. 356.28 ±169.29cc  (p=0.98), 953.15±346.55 vs 973.31±363.15cc (p= 0.83), 110.73 ±25.99 vs. 111.52 ±25.93cc (p=0.86) and 111.97 ±25.60 vs 112.32 ±25.58 cc (p=0.84) respectively]. Similarly, the maximum length, width and depth dimensions determined for bladder (p=0.88, 0.98 and 0.99 respectively), small bowel (p=0.97, 0.82 and 0.84 respectively), left femur (p=0.31, 0.90 and 0.94 respectively) and right femur (p=0.89, 0.84 and 0.93 respectively) were not significantly different between RTT and ROr.

Conclusion

There was a good concordance observed for the contouring of common OARs for rectal cancer among RTT and ROr after training. This can help in busy centres to help in role and responsibility distribution. With refinement and standardization of auto-contouring tools for common OARs, role of RTT may be explored for allowing routine evaluation, editing and approval of auto-contours for common OARs.