# Monitoring lung tumour volume on daily cone beam CT; is it achievable in a real-world setting?

## TL;DR

This study shows that lung tumor volume can be efficiently monitored using cone beam CT scans in real-world radiotherapy settings.

## Contribution

A semi-automated workflow for lung tumor delineation on CBCT is shown to be feasible and efficient in a clinical setting.

## Key findings

- 66% of patient scans were suitable for lung tumor delineation on 3DCBCT.
- Adjusting auto-contours on CBCT took a median of 83 seconds.
- Excellent agreement was found between Radiation Therapist and Radiation Oncologist volumes.

## Abstract

•66 % of patient scans were suitable for lung tumour delineation on 3DCBCT.•Adjustment of auto-contours on CBCT was efficient taking median of 83 (range 0–460) seconds.•Internal audit of generated volumes showed excellent agreement between RO and RTT.

66 % of patient scans were suitable for lung tumour delineation on 3DCBCT.

Adjustment of auto-contours on CBCT was efficient taking median of 83 (range 0–460) seconds.

Internal audit of generated volumes showed excellent agreement between RO and RTT.

Delineating the gross tumour volume (GTV) in non-small cell lung cancer (NSCLC) can be challenging due to anatomical complexities and imaging artefacts. This study evaluates a semi-automated workflow using commercial software for target volume (TV) delineation on cone-beam CT (CBCT) in patients undergoing radical radiotherapy. Seventy-six patients with 553 scans (n = 76 planning CT, n = 477 CBCT) were included. Auto-contours were adjusted by a senior Radiation Therapist and reviewed for accuracy. The majority (59.1 %) required only minor revisions, with median adjustment time of CBCT auto-contours of 83 (range 0–460) seconds. The findings support the feasibility of this approach, offering a pragmatic solution for adaptive radiotherapy workflows in NSCLC.