Effects of dwell time deviation constraint parameters on three-dimensional afterloading plan(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2018年第8期
- Page:
- 900-904
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of dwell time deviation constraint parameters on three-dimensional afterloading plan
- Author(s):
- JI Tianlong; ZHAO Jing; LI Quan; LI Guang
- Department of Radiation Oncology, the First Hospital of China Medical University, Shenyang 110001, China
- Keywords:
- ; cervical cancer; brachytherapy; simulated annealing; dwell time deviation constraint parameters; three-dimensional afterloading
- PACS:
- R737.3
- DOI:
- DOI:10.3969/j.issn.1005-202X.2018.08.007
- Abstract:
- Objective To study the effects of dwell time deviation constraint (DTDC) parameters on three-dimensional (3D) afterloading plan. Methods Fifteen patients with gynecologic tumors who were treated in the First Hospital of China Medical University were enrolled in this study. The source device was a single intrauterine tube of Fletcher applicator, all 3 tubes of Fletcher applicator and vaginal applicator. Each patient was scanned by CT before treatment, and the target areas and organs-at-risk were delineated by doctors. DTDC parameters were modified in the step of 0.1. A total of 11 plans were developed from DTDC=0 to DTDC=1, and the plans were normalized to DTDC=0 plan to obtain the corresponding values. The V150, V200 of CTV, D2cc of bladder and rectum, total dwell time, planned modulation indexes were compared, and the effects of DTDC parameter modification on 3D afterloading plan were analyzed. Results When using vaginal applicator, a single intrauterine tube of Fletcher applicator, all 3 tubes of Fletcher applicator, with the increase of DTDC, the V150 and V200 of CTV were increased to 105% and 109%, 102% and 104%, 115% and 120%, respectively; and the D2cc in rectum and bladder were increased/decreased to 101% and 102%, 99% and 99% , 115% and 101%, respectively. The total dwell time of DTDC=1 plan using vaginal applicator, a single intrauterine tube of Fletcher applicator and 3 tubes of Fletcher applicator reached 96%, 97% and 104% of that in DTDC=0 plan, respectively. Conclusion To provide a more reasonable treatment plans for patients, the optimal DTDC parameters should be selected based on different source devices used in 3D afterloading plan for cervical cancer.
Last Update: 2018-07-26