Dose-coverage rate volume histogram for lung tracking with Cyberknife based on voxels(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2024年第11期
- Page:
- 1343-1348
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dose-coverage rate volume histogram for lung tracking with Cyberknife based on voxels
- Author(s):
- ZHANG Jianping1; 2
- 1. Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou 350001, China 2. Fujian Clinical Research Center for Radiology and Radiotherapy for Digestive, Hematological and Breast Malignancies, Fuzhou 350001, China
- Keywords:
- Keywords: Cyberknife lung tracking treatment fractionation dose-coverage rate volume histogram
- PACS:
- R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2024.11.004
- Abstract:
- Abstract: Objective To calculate the inter-fractional dose-coverage rate volume histogram (CVH) of Cyberknife Xsight lung tracking based on voxels, and to investigate the correlation among tumor volume, anatomical location and CVH robustness. Methods A retrospective analysis was conducted on 55 peripheral lung cancer patients, with 26 in upper lobe, 22 in middle lobe and 7 in lower lobe, and there were 399 fractions. All patients were treated with Cyberknife (VSI) Xsight Lung tracking (2-view), with a scanning time interval of 60 s. The respiration tracking data recorded in Cyberknife motion tracking system were converted into patient coordinates. Based on the log files generated during Cyberknife treatment, the CVH of different margins were calculated with MATLAB on a voxel scale, and the correlation among anatomical location, tumor volume and CVH robustness was discussed. Results The target coverage rate (coverage of 95%, C95) greater than 95%, that is C95>95%, was taken as the evaluation criterion of whether the clinical requirements were met. Not coverage rate of all fractions met the clinical requirement when an evaluable treatment plan was delivered during treatment course. For the same margin, the value of CVH in order from the largest to the smallest was: upper lobe > middle lobe > lower lobe. The margin of 5 mm wont met the criterion of C95>95% for lung cancer in middle and lower lobes. There was a negative correlation between tumor volume and CVH robustness during treatment. The larger the tumor size, the smaller the fluctuation of CVH conversely, the smaller the tumor size, the greater the uncertainty of coverage during treatment and the poorer the robustness. For lower lobe lung tumors, the above phenomenon was more obvious. Additionally, CVH robustness improved with increasing margin. Conclusion For small volume and lower lobe lung tumors, the average coverage rate is lower than that of large volume and upper lobe lung tumor, and the margin should be comprehensively considered based on the factors such as tumor volume and location for further improving clinical efficacy.
Last Update: 2024-11-26