Vietnam Journal of Oncology, No. 5/2015, pp. 228-230
Authors: Nguyen Van Nam, Tran Ba Bach, Nguyen Dinh Long, Doan Trung Hiep, Ha Ngoc Son, Nguyen Van Han, Nguyen Trung Hieu.
Summary:
Objective: Analyze and evaluate patient setup errors before treatment. From there, draw experiences and notes to control errors well and increase stability in daily radiotherapy patient setup.
Subject: 2D-kV imaging data from 3D-CRT, VMAT plans of 30 cancer patients in 3 different areas: head-neck, chest-abdomen, and pelvis who were assigned to receive radiotherapy at the radiotherapy center at Vinmec International General Hospital from January 2015 to the end of August 2015.
Method: All patients were scanned with pre-radiation image guidance using the OBI system. 2D-kV images were analyzed directly on the OBI software and compared with the DRR images from the plan. From there, the setup errors in the 3 dimensions X, Y, and Z were evaluated.
Conclusion: A total of 488 2D-kV images were taken in all 3 radiation areas before daily treatment. For head and neck radiation, the setup error was approximately (2.0±0.9mm) on the X-axis, (2.0±1.0mm) on the Y-axis, and (1.15±0.9mm) on the Z-axis. For chest and abdomen radiation, the setup error was approximately (3.0±1.15mm) on the X-axis, (3.5±3.7mm) on the Y-axis, and (3.5±1.0mm) on the Z-axis. Setup error for the pelvic region in the X-axis (2.5±1.0mm), in the Y-axis (3.0±1.7mm), and in the Z-axis (2.5±2.5mm).
Conclusion: Image-guided radiotherapy using the OBI system helps reduce patient setup errors and increase the accuracy of dose distribution to the tumor. Thereby bringing good treatment results and minimizing side effects on healthy organs.
