Clinical implementation of real time motion management for prostate SBRT: A radiation therapist's perspective

Joanne Mitchell; Duncan B McLaren; Donna Burns Pollock; Joella Wright; Angus Killean; Michael Trainer; Susan Adamson; Laura McKernan; William H Nailon

doi:10.1016/j.tipsro.2024.100267

Clinical implementation of real time motion management for prostate SBRT: A radiation therapist's perspective

Tech Innov Patient Support Radiat Oncol. 2024 Aug 5:31:100267. doi: 10.1016/j.tipsro.2024.100267. eCollection 2024 Sep.

Authors

Joanne Mitchell^{1

2

3}, Duncan B McLaren^{1

2}, Donna Burns Pollock¹, Joella Wright¹, Angus Killean¹, Michael Trainer⁴, Susan Adamson¹, Laura McKernan¹, William H Nailon^{4

2

5}

Affiliations

¹ Department of Clinical Oncology, Edinburgh Cancer Centre, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK.
² Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK.
³ College of Medicine and Veterinary Medicine, the University of Edinburgh, UK.
⁴ Department of Oncology Physics, Edinburgh Cancer Centre, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK.
⁵ School of Engineering, the University of Edinburgh, the King's Buildings, Mayfield Road, Edinburgh EH9 3JL, UK.

Abstract

Background and purpose: The adoption of hypo-fractionated stereotactic body radiotherapy (SBRT) for treating prostate cancer has led to an increase in specialised techniques for monitoring prostate motion. The aim of this study was to comprehensively review a radiation therapist (RTT) led treatment process in which two such systems were utilised, and present initial findings on their use within a SBRT prostate clinical trial.

Materials and methods: 18 patients were investigated, nine were fitted with the Micropos RayPilot^TM (RP) system (Micropos Medical, Gothenburg, SE) and nine were fitted with the Micropos Raypilot Hypocath ^TM (HC) system. 36.25 Gray (Gy) was delivered in 5 fractions over 7 days with daily pre- and post-treatment cone beam computed tomography (CBCT) images acquired. Acute toxicity was reported on completion of treatment at six- and 12-weeks post-treatment, using the Radiation Therapy Oncology Group (RTOG) grading system and vertical (Vrt), longitudinal (Lng) and lateral (Lat) transmitter displacements recorded.

Results: A significant difference was found in the Lat displacement between devices (P=0.003). A more consistent bladder volume was reported in the HC group (68.03 cc to 483.7 cc RP, 196.11 cc to 313.85 cc HC). No significant difference was observed in mean dose to the bladder, rectum and bladder dose maximum between the groups. Comparison of the rectal dose maximum between the groups reported a significant result (P=0.09). Comparing displacements with toxicity endpoints identified two significant correlations: Grade 2 Genitourinary (GU) at 6 weeks, P=0.029; and no toxicity, Gastrointestinal (GI) at 12 weeks P=0.013.

Conclusion: Both the directly implanted RP device and the urinary catheter-based HC device are capable of real time motion monitoring. Here, the HC system was advantageous in the SBRT prostate workflow.

Keywords: Adaptive radiotherapy; Prostate cancer; Real-time tracking; SBRT prostate.