Session Item

There are two available motion management treatment techniques in our institute for liver SBRT radiotherapy treatment. We would like to compare the differences between these two techniques in clinical use.

A total of 20 patients were included in this study retrospectively. 7 patients were treated using SG-DIBH technique (Vision RT, UK) and 13 patients were treated using abdominal compression (AC) technique (Qfix, US). SG-DIBH patients were positioned using AlignRT. AlignRT dual-surface technique was applied for patient’s breath hold position. CBCT were taken under DIBH status. On the other hand, AC patients used the skin markings for positioning and the indexed compression bridge and plate to reduce the diaphragm motion to restrict the breathing magnitude. CBCT was taken before each treatment fraction as well. All CBCT data were recorded. t-test was used for data analysis. It was considered statistically significant if p<0.05.

The average and standard deviations of setup errors were (0.24±0.21)cm, (0.53±0.45)cm, (0.16±0.15)cm, (0.63±0.73)°, (0.87±1.07)°, (0.77±0.92)° and (0.30±0.21)cm (0.45±0.44)cm, (0.25±0.18)cm, (0.39±0.55)°, (0.41±0.43)°, (0.56±0.42)° in vertical, longitudinal, lateral, rotation, pitch and roll directions for SG-DIBH and AC groups respectively. Both techniques presented similar results. However, SG-DIBH is superior in lateral direction while AC treatment technique is better in pitch direction.

Both techniques are good to be used for liver tumor SBRT patient motion management. There are much lesser artifacts in SG-DIBH CBCT images which producing a better image quality. Diaphragm and liver contours can be seen clearer for precise matching.