Effects of setup error on the dosimetry of stereotactic body radiotherapy for liver cancer(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2020年第11期
- Page:
- 1360-1366
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of setup error on the dosimetry of stereotactic body radiotherapy for liver cancer
- Author(s):
- LU Shipei1; CHEN Yuxi1; 2; PAN Yinlin1; 2; 3; HUANG Sijuan1; YANG Xin1
- 1. Cancer Center of Sun Yat-sen University/State Key Laboratory of Oncology in South China/Collaborative Innovation Center for Cancer Medicine/Guangdong Provincial Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou 510060, China 2. Xinhua College of Sun Yat-sen University, Guangzhou 510520, China 3. Cancer Center of Guangzhou Medical University, Guangzhou 510095, China
- Keywords:
- Keywords: liver cancer image-guided radiotherapy stereotactic body radiotherapy setup error dosimetry
- PACS:
- R735.7；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2020.11.004
- Abstract:
- Abstract: Objective Under the guidance of cone-beam CT (CBCT) images, the setup error of stereotactic body radiotherapy (SBRT) for liver cancer was measured, and the effect of setup error on the PTV and organ-at-risk (OAR) dose in the target area was discussed. Methods 13 liver cancer patients who received SBRT was reviewed retrospectively. CBCT image was taken before each daily radiotherapy and then the gray-scale registration was done with the planning CT images. Based on the coach shifting parameters from the tumor target area and OAR position,the dose distribution in the planning system was calculated, and the effects of coach shifting parameters on a series of dosimetric parameters such as PTV, OAR dose, uniformity index (HI), and conformity index (CI) was analyzed. Results After correction, the setup errors in X, Y and Z directions are (0.47±2.00), (1.54±4.16) and (0.10±2.77) mm respectively, and the setup error is larger in Y direction. Compared with the minimum displacement, the maximum displacement has a significant effect on the target area, HI and CIF. As for OARs, compared with the original plan, the dose distribution of the maximum displacement in the left kidney and small intestine is statistically significant in the Dmean and Dmax, and the dose distribution of the minimum displacement in the right kidney is statistically significant in the Dmean. Conclusion The effect of setup error ≤3 mm on the dose of target area is smaller than that >5 mm, but the effect still has a significant impact on the minimum dose and coverage rate. In order to achieve accurate radiotherapy, the setup error should be minimized as much as possible.
Last Update: 2020-12-02