ESTRO 2022 - Abstract Book

S1643

Abstract book

ESTRO 2022

Results Translation and rotation M values were generally less than 1 mm and less than 0.6°, respectively. Statistical analysis between M values of the two populations led to comparable results, except for a significant improvement in X translational axis (p=0.006) and a significant degradation in Z rotational axes (p=0.003) in SK setup respect to BK. Both systematic and random translation errors were negligible and corrected by the Linac couch movement. The systematic and random rotational errors, which could not be corrected by standard treatment tables, resulted in less than 0.6° on the Y and Z axes for both devices. On the X axis, ∑ component was 1.38° for SK positioning and 1.44° for BK, while σ component was 0.91° and 1.05° for SK and BK, respectively. The overall number of problematic setup sessions was very low and limited to a small subset of patients. Conclusion Both positioning with straight knees and bended knees showed extremely high accuracy with no significant differences for moderated and extreme hypofractionated prostate radiotherapy. Patients experienced optimal comfort for the whole treatment duration with both devices. Notably, RTTs involved in patient positioning reported an overall perceived improvement in patient setup with straight knees and a substantial reduction in the procedure time.

PO-1852 SGRT for pre-positioning in SBRT lung treatments: accuracy and efficiency evaluation.

F. Cavallo 1 , S. Caponigro 1 , D. Di Minico 2 , G. Danaro 3 , L. Maida 3 , L. Capone 4 , L. Nicolini 4 , S.A. Allegretta 1 , F.M. Aquilanti 3 , P. Gentile 4 1 UPMC Italy, UPMC Hillman Cancer Center Villa Maria, Mirabella Eclano, Italy; 2 UPMC ITALY, UPMC Hillman Cancer Center Villa Maria, Mirabella Eclano, Italy; 3 Marrelli Hospital, Radiotherapy, Crotone, Italy; 4 UPMC Italy, UPMC Hillman Cancer Center San Pietro, Roma, Italy

Purpose or Objective