Background and purpose. The goal of the current study was to evaluate the commercially available atlas-based autosegmentation software for clinical use in prostate radiotherapy. The accuracy was benchmarked against interobserver variability.Material and methods. A total of 20 planning computed tomographs (CTs) and 10 cone-beam CTs (CBCTs) were selected for prostate, rectum, and bladder delineation. The images varied regarding to individual (age, body mass index) and setup parameters (contrast agent, rectal balloon, implanted markers). Automatically created contours with ABAS® and iPlan® were compared to an expert's delineation by calculating the Dice similarity coefficient (DSC) and conformity index.Results. Demo-atlases of both systems showed different results for bladder (DSC ABAS 0.86±0.17, DSCi Plan 0.51±0.30) and prostate (DSC ABAS 0.71±0.14, DSCi Plan 0.57±0.19). Rectum delineation (DSC ABAS 0.78±0.11, DSCi Plan 0.84±0.08) demonstrated differences between the systems but better correlation of the automatically drawn volumes. ABAS® was closest to the interobserver benchmark. Autosegmentation with iPlan®, ABAS® and manual segmentation took 0.5, 4 and 15-20 min, respectively. Automatic contouring on CBCT showed high dependence on image quality (DSC bladder 0.54, rectum 0.42, prostate 0.34).Conclusion. For clinical routine, efforts are still necessary to either redesign algorithms implemented in autosegmentation or to optimize image quality for CBCT to guarantee required accuracy and time savings for adaptive radiotherapy.
- Computed tomography
- Cone-beam computed tomography
- Prostate neoplasms
- Radiotherapy setup errors
ASJC Scopus subject areas
- Radiology, Nuclear Medicine and Imaging