ESTRO 2023 - Abstract Book

S861

Digital Posters

ESTRO 2023

Results During the GoLive preparation a total of 26 volunteers were scanned: 12 pelvis, 2 brain, 5 abdomen, 4 thorax, 3 head and neck, providing sufficient information about expected image quality, preferred acquisitions and familiarization with the machine and workflow. Screen recording became essential for timing and troubleshooting. The Zeus phantom was used for the end-to-end test (including cine MRI) and treatment interruption training. Since the clinical GoLive, a total of eight patients have been treated on the Unity following a hypofractionated 5-session regimen for lymph nodes (6), pancreatic tumour (1) and rectum (1). The patients spent an average of 48.3 minutes (range 28.9 - 76.5) on the treatment table (fig.2). Two patients were treated with adapt-to-position (ATP) only, four with adapt-to-shape (ATS) only, and two patients with a mix of both. ATS sessions lasted on average 12.7 minutes longer than ATP. All patients tolerated the treatments well. Two fractions out of forty were not completed as planned: one required a plan completion in the same day due to a machine problem, while the other required one day of delay because of a software connectivity issue. Weekly briefing meetings resulted in the development of a patient-specific “briefing sheet” to summarize the acquisition protocol (including functional sequences), contouring strategy and plan optimization particularities, to allow smooth communication among staff.

Conclusion Healthy volunteers and the Zeus phantom played a pivotal role in the preparation to GoLive with the Unity MR-Linac, especially combinined with screen capturing and off-line analysis. Weekly briefing meetings are warranted to optimize the online adaptive workflow.

PO-1077 Clinical linear accelerator power consumption: Can we reduce financial and environmental cost?

C. Stanford-Edwards 1 , S. Herbert 1 , R. Lewis 1 , R. Chuter 2 , M. Edwards 1