Application of conformity index in the evaluation of radiotherapy for cervical carcinoma(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2019年第3期
- Page:
- 265-270
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Application of conformity index in the evaluation of radiotherapy for cervical carcinoma
- Author(s):
- YANG Yugang1; QI Hongzhi1; XU Lin1; HAO Jie1; SHANG Ge1; ZHANG Ruili2
- 1. Cancer Center, the First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, China; 2. Postdoctoral Workstation, Changji Branch Hospital of the First Affiliated Hospital of Xinjiang Medical University, Changji 831100, China
- Keywords:
- ; Keywords: cervical cancer; conformity index; image fusion
- PACS:
- R812；R737.3
- DOI:
- DOI:10.3969/j.issn.1005-202X.2019.03.004
- Abstract:
- Abstract: Objective To evaluate the radiotherapy plan for cervical cancer with the use of conformity index (CI) of target areas. Methods A total of 10 patients with cervical cancer in the First Affiliated Hospital of Xinjiang Medical University were enrolled in this study. All patients were scanned by CT once a week before treatment. With the use of treatment planning system, the scanned images were fused with the image of the first radiotherapy plan. On the fused image, the target areas and organs-at-risk were segmented. Finally, the first radiotherapy plan was transplanted to the scanned image for further evaluating the dosimetric parameters of target areas and organs-at-risk. Results For each patient, several treatment plans, namely 7- and 5-field intensity-modulated radiotherapy and 4-field conformal radiotherapy plans, were designed in the whole course of radiotherapy for cervical cancer and then compared with the first plan. A strong positive correlation was found between the CI of target areas in treatment plans and the CI of the first plan (P<0.05), and a week correlation was found in homogeneity index. The changes in the V50 and V40 of the bladder and rectum were positively correlated with the target volume, with great changes, but the changes of the femoral head were relatively small. The maximum doses of the small intestine were different. However, because of the peristalsis of small intestine, the maximum dose points of the small intestine were different in all those plans, which resulted in an inaccurate evaluation. Conclusion There was no statistical difference in CI when the volume of bladder and rectum changed greatly. Therefore, CI can be used as a standard for evaluating the whole course of radiotherapy for cervical cancer.
Last Update: 2019-03-25