ESTRO 2024 - Abstract Book

S5571

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2024

Conclusion:

MR-Linac focal boost to intraprostatic GTV(s) with empty bladder was found to be feasible at our institution. However, 30% of the patients treated did not get their focal boost treatment on day 0 as planned due to large intrafraction motion. Further work to investigate strategies such as different bladder filling to mitigate intrafraction motion is needed.

Keywords: MRL, GTV boost, prostate cancer

2139

Digital Poster

Implementing prostate SABR in a regional setting in the absence of real-time seed-tracking

Amie Ross 1 , Anthony Karl 2 , Thomas Shakespeare 1

1 Mid North Coast Cancer Institute, Radiation Oncology, Coffs Harbour, Australia. 2 Mid North Coast Cancer Institute, Radiation Oncology Physics, Coffs Harbour, Australia

Purpose/Objective:

To design and implement a safe and efficient SABR program for the treatment of favourable intermediate and high risk prostate cancer patients in a regional setting without the use of real-time seed-tracking.

Material/Methods:

A literature review was undertaken of existing Prostate SABR treatment techniques and departmental infrastructure and machine capabilities were evaluated. Our department employs two Elekta Agility linear accelerators which are not equipped to perform real-time seed-tracking. Thus, the risks of not performing real-time seed-tracking were explored and steps were taken to mitigate the risk of tumour motion during treatment; which is typically caused by variations in bladder and bowel filling or natural prostatic motion. A treatment planning template, or class solution, was developed using Elekta’s Monaco Treatment Planning System using a single 10MV FFF beam to minimise treatment delivery time, and thus minimise the risk of intra-fraction motion. The utilisation of a class solution meant shorter planning timeframes and more consistent plans.

A regimented bladder and bowel protocol was developed and implemented to control inter and intra-fraction variation of bladder and bowel position which may impact the stability of the prostate.

A Cone Beam Computer Tomography (CBCT) protocol was developed to optimise image quality; without increasing image acquisition time, allowing faster on-treatment image review without introducing unnecessary treatment delays.