ESTRO 2022 - Abstract Book

S1443

Abstract book

ESTRO 2022

Conclusion We proposed to use simulated CBCT images to train a CNN segmentation model avoiding the need to gather complex and time-consuming reference delineations on CBCT images. As a perspective, robustness of the method against datasets from different institutions and from different CBCT devices will be assessed.

PO-1647 Commissioning and clinical beam characterization of the proton therapy compact-gantry system

S. Ruangchan 1,2 , I. Israngkul Na Ayuthaya 1,2 , M. Keawsamur 1,2 , S. Oonsiri 1,2 , S. Suriyapee 3,2 , T. Sanghangthum 3,2

1 King Chulalongkorn Memorial Hospital, Department of Radiology, Bangkok, Thailand; 2 Her Royal Highness Princess Maha Chakri Sirindhorn Proton Center, Department of Radiology, Bangkok, Thailand; 3 Chulalongkorn University, Department of Radiology, Bangkok, Thailand Purpose or Objective This work reports on the commissioning and clinical beam characterization of proton pencil beam scanning system, ProBeam Compact (Varian Medical System, Palo Alto, CA) at the first proton compact gantry in Thailand. Materials and Methods ProBeam Compact proton therapy system is a single room combined with the 360-degree gantry system and robotic couch, using the cyclotron accelerated proton beam for the pencil beam scanning technique. The proton system commissioning and clinical beam characterization of (1) radiation safety and interlock verification, (2) gantry and patient table mechanical testing, (3) CBCT and kV image acquisition, 4) proton beam characterization and data commissioning for Eclipse proton algorithms (Eclipse proton V.15.6, Varian Medical System) and (5) dosimetric validation and end to end test in the clinical condition were performed and discussed. Results Radiation safety was monitored and reported within the tolerance limit for all areas. The safety access control feature and emergency stop were well operated. The gantry and patient table mechanical tests showed a good performance within the acceptance criteria. The CBCT and kV image acquisitions were well functionally and suitable for the image-guided therapy procedure. For proton beam characterization, the results were in good agreement with the published work and theoretical calculation. Proton integral depth dose, in-air spot profile (figure 1),and the absolute dose calibration, together with the calibration curve of CT-HU and relative stopping power (figure 2) were successfully obtained and modeled into the Eclipse