| Objective To investigate the impacts of different CT-on-Rail matching models on set-up errors in hypofraction radiotherapy dealing with lung cancer. Methods Twenty-four patients were randomly selected from the First Affiliated Hospital of Anhui Medical University during Oct.2016 to Oct.2017.Each patient received CT-on-rail scan each week,and obtained images undergone online registrations with original ones in three different aspects,including grey-scale,bone and manual models.The translation deviations in X,Yand Z-axes were collected and analyzed statistically.Results The X, Y and Z axes set-up errors measured by gray-scale, bone and manual models were (0.21±0.16), (0.29±0.15), (0.37±0.22) cm respectively,(0.27±0.16), (0.35±0.25), (0.29±0.19) cm respectively, and (0.18±0.12), (0.28±0.16), (0.23±0.14)cm respectively. The results showed that the Y-axis set-up error was the largest, followed by the X-axis. The Z axis was the smallest, and the difference between three groups of data was statistically significant (P<0.05). Compared with bone model,the translation errors of grey-scale model on X,Y,Z axes were significantly reduced(P<0.05).Meanwhile,grey-scale model presented lower translation deviations on X and Z axes than manual model,which was statistically significant(P<0.05). Conclusions CT-on-rail could reduce set-up errors in lung cancer patients treated with IGIMHR,and the grey-scale model would be of top priority. |
