Dosimetric comparison between CT-guided free-hand intracavity/interstitial adaptive brachytherapy and conventional point-A brachytherapy in the treatment of cervical cancer
10.3760/cma.j.cn113030-20190312-00083
- VernacularTitle:CT引导徒手腔内联合插植自适应后装与传统A点后装治疗宫颈癌剂量比较
- Author:
Yanhong WANG
1
;
Weijun YE
;
Shizhao ZHAN
;
Yi OUYANG
;
Xinping CAO
Author Information
1. 福建医科大学附属第二医院放疗科，泉州 362000
- From:
Chinese Journal of Radiation Oncology
2020;29(10):882-887
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the dosimetric differences between CT-guided free-hand intracavity/interstitial brachytherapy[image-guided adaptive brachytherapy (IGABT)] and conventional point-A plan (CP) in the treatment of cervical cancer.Methods:Twenty-six cervical cancer patients who received four cycles of IGABT in Sun Yat-sen University Cancer Center were enrolled in this study. Two sets of CT images were obtained before and after applicator adjustment to aid in the design of CP and IGABT plans. The high-risk clinical target volume (HRCTV), point A, and organs at risk (bladder, rectum, and sigmoid colon) were defined on CT images. CP and IGABT plans were designed on CT images. Parameter differences between CP and IGABT plans were analyzed with paired t-test and Wilcoxon test. Results:According to the coverage index (CI) of CP, plans were divided into two groups: in group A (CI≥0.90), 20 CP and corresponding IGABT plans were included, and 84 CP and corresponding IGABT plans in group B (CI<0.90). The mean volume of HRCTV and mean tumor diameter in group A were significantly smaller than those in group B (46.7 cm 3vs. 62.1 cm 3, P<0.001 and 3.1 cm vs. 4.4 cm, P<0.001). Compared with CP, IGABT significantly improved the value of D 90% in all plans and group B, whereas lowered the bladder dose. IGABT also reduced the dose of sigmoid colon in group A. IGABT significantly improved conformal index and dose homogeneity index. Conclusions:IGABT can significantly improve the target coverage, conformal index and dose homogeneity index, protect organs at risk. Compared with CP, IGABT has advantages in the treatment of patients with bulky tumor.
