ESTRO 2024 - Abstract Book

S5926

RTT - Service evaluation, quality assurance and risk management

ESTRO 2024

2410

Poster Discussion

Online adaptive radiotherapy for anal cancer - time mapping and potentials for workflow optimization

Lisette J. Sandt, Katrine Smedegaard Storm, Patrik Sibolt, Lina M. Åström, Eva Serup-Hansen, Gitte Persson

Copenhagen University Hospital – Herlev and Gentofte, Department of oncology, Copenhagen, Denmark

Purpose/Objective:

Chemoradiotherapy is the primary treatment option for patients with anal cancer (AC). A high tumor control rate is, however, typically followed by significant treatment-related toxicity due to irradiation of surrounding normal tissue. The filling and emptying of the bladder and rectum cause large anatomical variations in the pelvis region, which is accounted for by the addition of substantial treatment margins. The use of cone beam CT-guided online adaptive radiotherapy (oART) allows for corrections of daily anatomical changes and enables treatment margin reduction thus minimizing the dose to organs at risk (OAR). This makes oART an attractive treatment option for patients with AC. The oART process can, however, be time-consuming and as the pelvic anatomical changes can fluctuate by the minute, the time perspective plays an important role.

The aim of this study was to identify factors in the oART workflow that affect time consumption in oART-process and the potential for workflow optimization.

Material/Methods:

The first 35 patients from the prospective phase II trial ROAR-A (Re-optimization based Online Adaptive Radiotherapy of Anal cancer), treated with cone beam CT-guided oART were included in the study. Data regarding the time consumption of each step in the adaptive workflow (Figure 1) were included for analysis. In December 2022, the procedure for Influencer review was optimized to create a faster adaptive workflow. The time consumption of Influencer review before and after the optimization was included in this analysis. Furthermore, the time consumption of Target review and Plan review and QA was analyzed separately for patients with and without pathological lymph nodes were selected for analysis.

Results: