ESTRO 2024 - Abstract Book

S5896

RTT - Service evaluation, quality assurance and risk management

ESTRO 2024

1211

Digital Poster

Prostate SABR radiotherapy on the MR Linac: how can we improve service efficiency?

Lisa McDaid 1 , Claire Nelder 1 , James Tallon 1 , Benedict Dobby 1 , Lee Whiteside 1 , Joe Berresford 1 , Martin Swinton 1 , Ananya Choudhury 1,2 , Cynthia L Eccles 1,2 1 The Christie NHS Foundation Trust, Radiotherapy, Manchester, United Kingdom. 2 University of Manchester, Faculty of Medicine, Biology and Health, Manchester, United Kingdom

Purpose/Objective:

To build MR Linac service capacity at our institute, a continuous quality improvement audit of treatment times for prostate radiotherapy showed duration of treatment times were unacceptably long. We report this audit findings and proposed solutions.

Material/Methods:

An audit of MRI-guided radiotherapy for all prostate cancer treatments from May 2019 to April 2023 was undertaken to determine the length of time each fraction was taking. Patients were treated with either 60 Gy in 20 fractions (#) over four weeks, or 36.25 Gy in 5# on alternative days, in a 60 minute treatment slot for each #. Treatment times (T#) for all patients were obtained from the oncology management system for all fractions. T# was defined as the time the patient entered the controlled access area for the final identification and MRI safety check for that session, until the time the treatment delivery was complete, and the patient left the room. This included patient positioning, pre fraction imaging and registration, asking patients to get off the table to adjust bladder or bowel filling (if necessary), repeat image verification, independent dose checking and treatment delivery. Reasons for all T# ≥ 60 mins were recorded. Based on the results of the audit, changes to appointment process were made. Changes were (1) ensuring clerical staff were including relevant information sheets and (2) changing the colour of information sheets relating to bowel preparation to focus attention to them to patients. T# were then re-audited.

Results:

149 patients who underwent 20 fraction (n=39) or 5 fraction (n=89) MRI guided prostate radiotherapy were included in this audit. The median time for treatment of all patients across all fractions was 51:33 min (range 32:08 min to 284:18 min). 20 fraction patients were quicker than 5 fraction with median times of 46:43 min (range 33:08 min to 284:18 min) and 54:33 min (40:28 min to 141:02 min) respectively (Figure 1). The most common reasons for treatments exceeding 60 minutes in 37 patients (28.9%) over 52 appointments were that the bladder or the rectum was too full (Figure 2). On average patients who needed to void their bladder incurred a 15–20-minute delay; those who needed to administer repeat enemas incurred a 30-minute delay. Figure 2 illustrates those patients, and frequency, whose treatments were delayed at more than one timepoint during their course of radiotherapy. 23 of these 37 patients (62.2%) had to get off the treatment couch more than once during a single fraction.