Abstract：Objective The effects of three different volume of interest (VOI) registration ranges on the accuracy of abdominal tumor
placement verification were investigated by using image verification system (IVS) developed by Suzhou Reitel. Methods The
positioning images of anthropomorphic pelvic phantom and 20 groups of IVS images with known position deviations were obtained
for registration. Three different VOI ranges were selected to obtain the positioning errors of three-dimensional translation direction
for comparative analyzed. Results The VOI of 35 cm×35 cm×35 cm was selected as the minimum positioning error. Compared
with VOI of 25 cm×25 cm ×25 cm×25 cm and 10 cm×10 cm×10 cm, the positioning errors in x, y and z directions had
significant statistical differences (P<0.05). Conclusion For pelvic tumors, VOI of image registration range 35 cm×35 cm×35 cm is
recommended to minimize the error of registration results.
