Realization and clinical application of image pasting for cone-beam computed tomography / 中华放射肿瘤学杂志

ABSTRACT

Objective To enlarge the scan width of cone-beam computed tomograpby(CBCT) and offer the integrity of structures( including tumor targets and organs at risk) on CBCT images by pasting the CBCT images together without gap or data lost. Methods Patients received CBCT scan twice at different longitude position. The two CBCT image series were then imported to TPS and fused with the planning CT. The same layer of two CBCT series was found by analyzing the two fusion results and recording their sequence numbers. The CBCT image series and the sequence numbers were sent to" CBCT Pasting", a special software we developed for this investigation. Then the software merged the CBCT series into the same reference flame. To validate the feasibility of CBCT Pasting,we observed its geometric characteristics by patients and phantoms. Results On the images of phantom, the difference was 0.26% (28.34 cm3) of the total body volume,and 1.87% (12.82cm3) and 1.47%(10.07cm3) of the two lungs between CT and CBCT images. On the images of patients, the difference was 1.97% (64.53cm3) ,2.30%(33.32cm3) and 1.75%(31.21cm3) for the total-lung,the left lung and the right lung. Conclusions The CBCT scan and pasting can enlarge the scan width without image data lost. This technique can provide a chance to observe the whole target and OAR and help physicists to evaluate the treatment plan.