ESTRO 2024 - Abstract Book

S5497

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2024

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[2] D. W. Litzenberg et al., “Influence of intrafraction motion on margins for prostate radiotherapy,” Int. J. Radiat. Oncol. Biol. Phys., vol. 65, no. 2, pp. 548–553, Jun. 2006, doi: 10.1016/j.ijrobp.2005.12.033.

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[5] L. A. Dawson, K. Mah, E. Franssen, and G. Morton, “Target position variability throughout prostate radiotherapy,” Int. J. Radiat. Oncol. Biol. Phys., vol. 42, no. 5, pp. 1155–1161, Dec. 1998, doi: 10.1016/s0360-3016(98)00265-x.

809

Digital Poster

Comparison of SGRT and arch-ruler positioning method in thoracic radiotherapy patients

Wenwen Wu, Lunjie Lu, Yike Xu, Hui Wang, Ning Wen, Hua Shao, Zongchun Zhang, Xianyu Huang

Qingdao Central Medical Group, Radiation Oncology, Qingdao, China

Purpose/Objective:

Arch-ruler localization has been implemented in our institution as a standard positioning method over the past decade. It provides good accuracy, however, it requires manual handling of the measuring tool with many steps involved before and during positioning workflow. Hence, we would like to initiate our investigation into the feasibility of the use of SGRT, in particular, thoracic radiotherapy patients.

Material/Methods:

30 thoracic radiotherapy patients were positioned using arch-ruler (Method A) and SGRT (Method B) on alternate days. All patients were scanned on a fiducial wire embedded baseplate. The indexing of the arch-ruler and body markings were all marked and recorded accordingly. Arch-ruler absolute treatment position (isocenter) was calculated using an internal software. When Method A was in used, patient was aligned to the arch-ruler CT indexed position and two red lasers. These two red lasers should go in line with two black dots on the patient’s body. Couch was then shifted to the calculated arch-ruler absolute treatment position. During SGRT positioning, on the other hand, the patient was shifted near to the isocenter according to the isocenter indicated on SGRT (AlignRT, UK) reference