Akademik Veri Yönetim Sistemi
TURK ONKOLOJI DERGISI-TURKISH JOURNAL OF ONCOLOGY, sa.2, ss.95-103, 2025 (ESCI)
OBJECTIVE The aim of this study was to evaluate the intra fractional tumor displacement by CBCT of patients with liver cancer who underwent stereotactic body radiotherapy in the presence of abdominal compression. METHODS Twenty patients with liver cancer, scheduled for stereotactic body radiotherapy, were included in the study. An abdominal compression was applied to all patients to reduce tumor motion amplitude and ensure repeatable tumor movement. To determine the extent of intra fractional tumor displacement in the presence of abdominal compression, pre-and post-treatment CBCT images for all fractions were evaluated. RESULTS The analysis of 3D-CBCT images taken before and after treatment revealed the following average tumor position errors: 1.frx: 0.60 +/- 0.64mm in the AP direction, 0.82 +/- 1.00mm in the CC direction, 0.35 +/- 0.28 mm in the ML direction, and a total displacement vector (VT) of 1.29 +/- 0.98 mm. 2.frx: 0.21 +/- 0.24 mm in the AP direction, 0.47 +/- 0.62 mm in the CC direction, 0.26 +/- 0.32 mm in the ML direction, and a VT of 0.68 +/- 0.64 mm. 3.frx: 0.15 +/- 0.30mm in the AP direction, 0.37 +/- 0.48 mm in the CC direction, 0.74 +/- 1.91 mm in the ML direction, and a VT of 1.04 +/- 1.89mm. CONCLUSION Respiratory-related liver motion can lead to the creation of a large ITV for liver tumors, and therefore this effect should be reduced by appropriate immobilization techniques. Abdominal compression is a quite effective equipment to prevent intra-fractional position errors by limiting the movement of intraabdominal organs. This study demonstrated that when the abdominal compression method is used, the intra fractional motion of liver tumors remains within the 5 mm PTV margin.