Development of Eclipse Scripting API for Automatic Delineation of Femoral Head

Contouring of organs at risk is an important but time consuming part of radiotherapy treatment planning. This procedure is usually performed by manual contouring and it may take several hours to delineate all structures of interest by radiation oncologists. This work presents an algorithm for automatic delineation of the femoral bone used as tool within Eclipse^® software to save time of radiation oncologists. The Eclipse’s script was successfully characterized in pelvic CT Scan DICOM files of prostate patients (n = 11) from two different hospitals, AC Camargo Cancer Center and Sao Paulo Hospital. The automatic delineation was compared with manual and approved delineation through blind test evaluated by a panel of seniors radiation oncologists (n = 9) from both hospitals and the overlapping evaluation was assessed using Dice similarity coefficient. Clinical experts considered that no corrections were needed in 77.8% and 67.8% of manual and automatic delineation respectively. A similarity of 0.94 ± 0.07 was achieved between manual and automatic delineation for the lesser trochanter, 0.91 ± 0.07 for femoral neck, and 0.86 ± 0.08 for femoral head. The results showed that the automated delineation was reproducible in all patient and its performance was similar to manual delineation. In conclusion, the script is capable to relieve the physician of time-consuming tasks and shows the great potential to be employed for automatic segmentation of organs at risks in pelvic or others anatomical body regions.