ESTRO 2024 - Abstract Book

S5931

RTT - Service evaluation, quality assurance and risk management

ESTRO 2024

Stefano Leva 1 , Jonathan Alberton 1 , Paula Sargenti 1 , Stefano Moretto 1 , Davide Giovanni Bosetti 1 , Gianfranco Angelo Pesce 1 , Letizia Deantonio 1 , Rossella Cavicchiolo 1 , Lisa Milan 2 , Stefano Presilla 2 , Thomas Zilli 1,3,4 1 EOC-IOSI, Radiation Oncology Clinic, Bellinzona, Switzerland. 2 EOC-IIMSI, Medical Physics Division, Bellinzona, Switzerland. 3 Università della Svizzera Italiana (USI), Facoltà di Scienze Biomediche, Lugano, Switzerland. 4 University of Geneva, Faculty of Medicine, Genève, Switzerland

Purpose/Objective:

Since December 2021, our Institute is equipped with a dedicated MRI (Philips Ambition X) unit for simulation of radiation therapy (RT) treatments. The commercial Magnetic Resonance for Calculating ATtenuation (MRCAT®) software is utilized for synthetic CT reconstruction in the pelvic region, primarily for the treatment of prostate, rectal, and gynecological cancers. Considering the relatively long time acquisition of the different MRI sequences (20 minutes), rectum and bladder preparation is crucial for obtaining images suitable for planning and treatment purposes. A well-established collaborative workflow has been implemented, involving a dedicated nurse responsible for administering the rectal enema and ensuring a 500 mL bladder fill one hour before the simulation, and a radiation therapist (RTT) who utilizes a bladder scan to verify the accurate bladder volume. This process ensures the proper execution of the MRI-only simulation procedure. Since the introduction of this workflow, it has been decided to allocate a 2-hour time slot. Aim of the present study is to analyze the real overall duration of the whole procedure in order to optimize our internal simulation workflow.

Material/Methods:

The total duration of an MRI-only simulation process were retrospectively analyzed for 50 patients undergoing pelvic radiotherapy at our institution during 2023.

The time slots considered were as follow: 1) end of bladder filling preparation calculated in collaboration with the nurse; 2) time of bladder scan; 3) end of T2-weighted MRI sequence acquisition to verify the proper preparation; 4) patient discharge and any setbacks.

Results:

The median age of the 50 analyzed patients was 68 years (range min-max 35- 86), with a male/female ratio of 8. The median preparation time was 27 minutes (range 22-37), while the median time between the end of preparation and the end of bladder scan was 49 minutes (range 36-65).The median time between the bladder scan and the first T2 weighted sequence was 11 minutes (range 10-29) and until the patient discharge was 24 minutes (range 15-33). Some observed delays were mostly related to difficulties in the bladder and rectum preparation. Overall, 16% of the patients (n=8) had to wait more time between the different steps for an incomplete bladder filling or issues related to the rectal volume, with an additional waiting time of 21 minutes (range 8-35). Moreover, 6/50 patients had to return another time due to inadequate preparation (12%). The overall median timing for the whole procedure was 111 minutes, ranging from 91 to 121 minutes.

Conclusion: