Application of autosegmentation software in esophageal cancer / 中华放射医学与防护杂志

ABSTRACT

Objective To evaluate the geometric and dosimetric accuracy of autosegmentation software for contouring the organ-at-risk ( OAR) of esophageal cancer, and discuss its clinical feasibility. Methods A total of 10 patients were enrolled, and single and multi-template were adopted respectively to auto-delineate corresponding OARs on target CT images based on image registration. The geometric consistency including volume difference (&Delta;V) , dice similarity ( DSC) and position difference (&Delta;x, &Delta;y,&Delta;z) between the two autosegmentation method and manual were compared using Wilcoxon signed-rank test. And the correlation between DSC and OAR volume was analyzed. In addition, to evaluate the clinical feasibility of autosegmentation, the dose distributions of all OARs were compared using Friedman test. Results The average DSC of all OARs obtained by single and multi-template were 0.82 ± 0.17 and 0.92 ± 0.54, respectively, with statistically significant difference (Z= -2.803- -2.497, P<0.05). A positive correlation between DSC of the autosegmentation and OAR volume was found by spearman analysis, and the single-template was not good enough for the spinal cord with smaller volume. The positional deviations of multi-template group were less than 0.5 cm in three directions, which were better than single-template group. The main dosimetric indexes of single-template and multiple-template were similar to manual coutours. V20 of whole lung were 23.2％, 22.4％ and 22.1％, Dmeanof whole lung were (11.3 ±4.0), (11.1 ±4.5) and (11.0 ±4.3) Gy, Dmaxof spinal cord were (40.3 ±4.8), (38.2 ±6.7) and (39.4 ± 5.3) Gy, respectively, and V30 of heart were 16.0％, 15.8％ and 15.5％, respectively. There was no statistical difference between the three methods (P>0.05), and all of the dosimetric indexes were in line with the requirements of clinical dose limits. Conclusions The autosegmentation software can achieve satisfactory precision for the OARs of the esophageal cancer patients, and the multi-template method is better than the single-template, which is more suitable for clinical application.