Radiation safety in patients with ureteral stent placement undergoing postoperative radiotherapy for cervical cancer

Abstract

This study aimed to investigate radiation safety in patients with ureteral stent implantation undergoing radiotherapy. We enrolled 15 patients with ureteral stents undergoing postoperative radiotherapy for cervical cancer at the Chongqing University Cancer Hospital from November 2016 to April 2018. Computed tomography localization, target delineation, and radiotherapy planning were performed. The treatment group was the stent group, and the control group was the stent-free group. The high radiodensity HU value of ureteral stents on computed tomography was replaced by liquid radiodensity using density-filling technology, and the stent-free group was optimized with the same parameters. The Monte Carlo method was used to calculate the γ passing rate of the planning target volume and organs at risk (OARs). The conformal index, homogeneity index, and OAR receiver were compared between the two groups. The results showed that the γ passing rate of both groups met the clinical requirements. The target conformal index results were 0.88±0.03 and 0.90±0.03 in the stent and stent-free groups, respectively (p<0.05). The homogeneity index result did not differ significantly between the two groups (p>0.05). D2%, D98%, Dmean, and OARs in the stenting group were significantly higher than those in the stent-free group, and only the small intestine and ureter showed significant differences (p<0.05). The contribution rate of ureteral stents to target sites and OAR dose were <5%. In conclusion, ureter stent implantation during radiotherapy affects the postoperative target area and OAR radiation dose in patients with cervical cancer, but the contribution rate is <5%, which has little influence on clinical treatment outcome, and radiotherapy is relatively safe.

Keywords

• cervical cancer postoperative
• ureteral stent
• density filling technology
• monte carlo