Comparison of three-dimensional-printed template-guided and traditional implantation of125I seeds for gynecological tumors
Authors: Kang Weiming , Zhang Hongtao , Liang Yansong , Chen Enli , Zhao Jinxin , Gao Zhen , Wang Juan 
Published: July 2021

Objective:
The objective of the study was to compare the dose parameter and clinical efficacy of three-dimensional-printed template (3D-PT)-guided and traditional 125I seed implantation in treatment of gynecological tumors.

Materials and Methods:
A total of 28 patients with gynecological tumors treated with radioactive seed implantation in Hebei General Hospital from January 2016 to December 2018 were retrospectively analyzed. Twelve patients (template group) were guided by 3D-PT and the remaining 16 patients (traditional group) were guided by computed tomography (CT) with traditional technique. Preoperative treatment plan (preplan) was completed through a treatment planning system. In the template group, 3D-PT was printed according to preplan and seeds were implanted under the guidance of 3D-PT and CT. In the traditional group, seeds were implanted under the guidance of single CT directly according to the preplan. Postoperative verification plan (post-plan) was completed. Dose–volume histogram (DVH) was calculated and D80, D90, V90, V100, and V150 were obtained according to DVH. Then, deviation of the dosimetric parameters D80, D90, V90, V100, and V150 between the preplan and postplan were compared within the two groups. The difference and percentage of difference of the above dosimetric parameters between the preplan and postplan within the two groups were calculated using the formula Xd= Xpost-plan–Xpre-plan, and Xd% = (Xpost-plan–Xpre-plan)/Xpre-plan× 100%. Doses were calculated to determine whether the differences there were statistically significant. Efficacy evaluation was completed according to RECISIT 1.1. Local control rate and effective rate of 2-months postplan were compared between the two groups. Survival analysis was completed by the Kaplan–Meier method. The patients were followed up for 12 months, and their survival rate was calculated and compared.

Results:
There was no significant difference between the two groups for all the parameters, except for D80 of the preplan and postplan in the traditional group (P = 0.000). All the differences and percentage of difference were calculated and it was found that the Xd difference of D80 (P = 0.035), D90 (P = 0.023), V90 (P = 0.047), V100 (P = 0.032), and V150 (P = 0.031), as well as the Xd% difference of D80 (P = 0.032), D90 (P = 0.034), V90 (P = 0.042), V100 (P = 0.036), and V150 (P = 0.044) of the two groups was statistically significant, thus indicating that the dosimetric parameter fluctuation in the template group was more stable. The result of the curative effect after 2 months were as follows: the local control rate and effective rate of the template group were 100% (12/12) and 83.3% (10/12), while those of the traditional group were 100% (16/16) and 81.2% (13/16). There was no statistically significant difference in the curative effect between the two groups. After 6–27 months (median = 12 months) of follow-up, the median survival time of the template group and traditional group were 17 (10–23) and 16 (11–20) months, respectively, and the 1-year overall survival rate was 63% and 79% (P = 0.111), respectively, with no statistically significant difference observed.

Conclusion:
3D-PT-guided 125I seed implantation is safe and effective in the treatment of gynecological tumors.