Thyroid dosimetric comparison of different techniques for supraclavicular radiotherapy of breast cancer and their effects on survival time and lymphocyte subsets(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第2期
- Page:
- 143-147
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Thyroid dosimetric comparison of different techniques for supraclavicular radiotherapy of breast cancer and their effects on survival time and lymphocyte subsets
- Author(s):
-
ZHOU Zhanming1; XU Tao1; SHU Qi2
- 1. Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China 2. Department of Oncology, Chongqing Peoples Hospital, Chongqing 400013, China
- Keywords:
- Keywords: breast cancer supraclavicular region intensity-modulated radiotherapy three-dimensional conformal radiotherapy thyroid lymphocyte subset
- PACS:
- R737.9；R815
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.02.003
- Abstract:
- Abstract: Objective To compare the thyroid dosimetric characteristics of different supraclavicular radiotherapy techniques for breast cancer, and to compare their effects on survival time and lymphocyte subsets. Methods According to the radiotherapy plan after radical mastectomy, 71 patients with breast cancer were divided into intensity-modulated radiotherapy (IMRT) group (n=37) and three-dimensional conformal radiotherapy (3D-CRT) group (n=34). The dose of planning target volume (PTV), thyroid dose, changes of lymphocyte subsets before and after radiotherapy, 5-year disease-free survival rate and overall survival rate were compared between two groups. Moreover, the thyroid-sparing effect of two radiotherapy technologies and their effects on the prognosis of patients were also compared. Results Compared with those in 3D-CRT group, the Dmean and CI of PTV in IMRT group were higher, while the Dmax and HI of PTV were lower, with statistical differences (P<0.05). Some dosimetric parameters (V20, V30, V40, Dmin and Dmean) of the thyroid in IMRT group were higher than those in 3D-CRT group, with statistical differences (P<0.05). After radiotherapy, the total number of lymphocytes and the percentage of B lymphocytes in the two groups were decreased, while CD3+ and CD4+ were increased. The total number of lymphocytes, the percentage of B lymphocytes, CD3+ and CD4+ in 3D-CRT group were higher than those in IMRT group on 1 day after radiotherapy, and the differences were statistically significant (P<0.05). Three cases were lost in IMRT group and 1 case in 3D-CRT group. The other patients were followed-up for more than 5 years. The differences between IMRT group and 3D-CRT group in 5-year disease-free survival rate ［47.06% (16/34) vs 51.52% (17/33)］ and overall survival rate ［73.53% (25/34) vs 78.79% (26/33)］ were trivial, without statistical difference (P>0.05). Conclusion IMRT has better target dose uniformity, but leads to higher thyroid dose and more obvious changes of lymphocyte subsets after radiotherapy. There is no significant difference between IMRT and 3D-CRT in the long-term survival of breast cancer patients.
Last Update: 2021-02-02