ESTRO 2024 - Abstract Book

S2833

Interdisciplinary - Health economics & health services research

ESTRO 2024

Radiation Oncology, Wuhan, China. 8 First Hospital, Peking University, Department of Radiation Oncology, Beijing, China

Purpose/Objective:

Since the introduction of Spot-scanning Proton Arc therapy in 2016, this new treatment modality has drawn significant interest in the radiation oncology community.[1] Besides the potential clinical benefits through better dosimetric plan quality and superior LET modulation capability [2], SPArc therapy shows the possible improvement in simplifying the clinical workflow and reducing the overall patient’s daily treatment time per fraction [3]. However, most reports are based on a single- room proton therapy center’s experience. Currently, there are no quantitative investigations to explore such benefits across all proton solutions.

Material/Methods:

A new treatment workflow simulation tool was developed based on three main aspects: (1) Machine and clinical workflow-related factors, including the gantry rotation time and delays, loading field delay (file transfer from Oncology Information System to proton therapy system), and treatment field preparation time4. (2) Patient setup time, including Imaging acquisition, alignment (10.3mins) and anesthesia procedure (est. 20 mins on top of the routine setup time). (3) treatment irradiation time, including number of treatment fields and average irradiation time per field (average 2.4mins per IMPT field and 4mins per SPArc field) [3,5]. Other factors include room switching time (30s) and patient walk in/out time (3min per patient) are also considered. The simulator is validated based on the two institutions' clinical logfile (single-room and two-room systems). Total predicted number of patient treatments is estimated based on the simulator and compared to the clinical logfile. The efficiency of the usage of the accelerator in a 2-room system is compared based on the simulator and accelerator logfile (beam time/total clinical operation time) based on the patient population fixed treated on that clinical day. Once the simulator is validated, it is used to estimate the daily treatment throughput (total number of patients treated per day) and patient waiting time (The time that patient finishes IGRT procedure and waiting for the proton beam) on the treatment couch, based on the different patient population mix (a) 80% patient without anesthesia and 20% anesthesia pediatric patients; (b) 100% patient without anesthesia assuming a 15-hour clinical operation day. The validation results showed a good agreement in the daily treatment throughput between the clinical logfile and the simulator’s prediction using random clinical operation day. More specifically, the simulator predicts 33.44 patient treatments per day in 8.3 clinical hours for a two-room system compared to 35 patients treated (95% patients without anesthesia and 5% with anesthesia) on that day and 23% of the duty cycle of the accelerator compared to 26% recorded on the accelerator logfile. For the single-room system, it predicted 22.9 treatments per day in 11 clinical hours compared to 21 patients treated on that clinical day (80% of patients w/o anesthesia and 20% of pediatric patients with anesthesia). Regarding the maximum daily treatment throughput (15-hour clinical operation) prediction, SPArc therapy can increase 25% (8 more treatment fractions), 33% (20 more treatment fractions), 47% (37 more treatment fractions), 62%(56 more treatment fractions), and 77%(72 more treatment fractions) in scenario (a): 80% w/o anesthesia and 20% w anesthesia) (Figure 1) and 32% (12 more treatment fractions), 43% (29 more treatment fractions), 63% (54 more treatment fractions), 78%(74 more treatment fractions), and 86%(82 more treatment fractions) (in scenario (b): 100% w/o anesthesia) for single-room, two-room, three room, four-room, and five-room proton therapy center, respectively. The study also found that SPArc therapy is able Results: