Dosimetric study of helical tomotherapy for high-risk prostate cancer under different jaw modes(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2020年第2期
- Page:
- 138-144
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Dosimetric study of helical tomotherapy for high-risk prostate cancer under different jaw modes
- Author(s):
- FANG Chunfeng1; 2; XIE Chuanbin1; XU Shouping1; DAI Xiangkun1; XU Wei1; SONG Yuanyuan2; WANG Zishen2
- 1. Department of Radiation Oncology, the First Medical Center of Chinese PLA General Hospital, Beijing 100853, China; 2. Department of Radiation Oncology, Hebei Yizhou Cancer Hospital, Zhuozhou 072750, China
- Keywords:
- Keywords: prostate cancer; high-risk stage; helical tomotherapy; jaw mode; dosimetry
- PACS:
- R737.25；R312
- DOI:
- DOI:10.3969/j.issn.1005-202X.2020.02.002
- Abstract:
- Abstract: Objective To explore the dosimetric characteristics of target areas and organs-at-risk (OAR) in high-risk prostate cancer patients treated with helical tomotherapy for local irradiation combined with pelvic lymph node irradiation under different jaw modes (static state and dynamic state). Methods Eight patients with high-risk prostate cancer scheduled for local irradiation combined with pelvic lymph node irradiation were enrolled in this study. Three groups of static plans with the jaw widths of 1.050, 2.512 and 5.050 cm (F1.050, F2.512 and F5.050) and two groups of dynamic plans with the jaw widths of 2.512 and 5.050 cm (D2.512 and D5.050) were designed for each patient. The dose distributions and dose-volume histograms of target areas and organs-at-risk, delivery time and monitor units were compared among different plans. Results Under different jaw modes, the dosimetric difference of target areas was trivial, without statistical differences (P>0.05). For the dosimetric comparison of rectum, bladder and femur head, with the same jaw width, dynamic jaw plan was almost the same as static jaw plan; however, static jaw plan was obviously superior to dynamic jaw plan with larger jaw width when the jaw width was different. Dynamic jaw technique had obvious dosimetric advantages in the dose to normal tissues. The average monitor units and average delivery time of 5 plans were increased with the order of F5.050, D5.050, F2.512, D2.512 and F1.050. Conclusion For patients with high-risk prostate cancer scheduled for local irradiation and pelvic lymph node irradiation, dynamic jaw mode has limited advantages and reduces the delivery efficiency.
Last Update: 2020-03-03