# Investigating the use of comprehensive motion monitoring for intrafraction 3D drift assessment of hypofractionated prostate cancer patients on a 1.5T magnetic resonance imaging radiotherapy system

## TL;DR

This study explores a motion monitoring system for tracking prostate movement during MRI-guided radiotherapy, finding that further improvements are needed before clinical use.

## Contribution

The novel contribution is the evaluation of a comprehensive motion monitoring system for 3D drift assessment in prostate cancer radiotherapy.

## Key findings

- CMM-derived prostate motion was compared to a 3D reference, showing discrepancies in tracking.
- SI motion tracking quality was low, with mismatches exceeding 2 mm between anatomical planes.
- Further improvements in motion tracking accuracy are needed before clinical implementation.

## Abstract

This work investigates the use of a multi-2D cine magnetic resonance imaging-based comprehensive motion monitoring (CMM) system for the assessment of prostate intrafraction 3D drifts. The data of six healthy volunteers were analyzed and the values of a clinically-relevant registration quality factor metric exported by CMM were presented. Additionally, the CMM-derived prostate motion was compared to a 3D-based reference and the 2D-3D tracking agreement was reported. Due to the low quality of SI motion tracking (often >2 mm tracking mismatch between anatomical planes) we conclude that further improvements are desirable prior to clinical introduction of CMM for prostate drift corrections.