Efficacy and dosimetric analysis of (125)I seeds implantation for pelvic recurrent cervical cancer after radiotherapy under CT guidance

Abstract

Objective: To evaluate the relationship of dosimetry parameters and efficacy of (125)I seeds implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy(EBRT) under CT guidance. Methods: A retrospective analysis was made on 30 PRCC patients after EBRT in Peking University Third Hospital with (125)I seeds implantation under CT guidance. Postoperative plans were made to evaluate the dosimetric parameters. Kaplan-Meier method was used to calculate local progression free survival (LPFS) rate and overall survival (OS) rate, and Log-rank test and Cox regression were used for univariate and multivariate analysis. Results: The 1-year and 2-year LPFS rate was 39.4% and 22.5%, respectively. The 1-year and 2-year OS rate was 57.3% and 27.4%, respectively. On postoperative plan, D(90) was (132±47) Gy, D(100) was (51±24) Gy, V(100) was 88%±10%, V(150)was 69%±15%, V(200) was 51%±18%.LPFS time would be longer while D(90) ≥105 Gy or D(100) ≥ 55 Gy or V(100) ≥ 91% (all P<0.05). D(100) was significantly related to LPFS (P<0.05). But these dosimetry parameters got no effect on OS. Conclusions: LPFS time of (125)I seeds implantation for PRCC after EBRT under CT guidance would be longer when D(90)≥105 Gy or D(100)≥ 55 Gy, or V(100)≥ 91%. D(100) is an independent factor related to LPFS.