CT-guided ¹²⁵I interstitial brachytherapy for pelvic recurrent cervical carcinoma after radiotherapy

This retrospective study aimed to evaluate the feasibility, safety, and clinical efficacy of computed tomography (CT)-guided ¹²⁵I seed interstitial brachytherapy for pelvic recurrent cervical cancer in patients with a history of pelvic radiotherapy.

From March 2011 to December 2015, 35 pelvic recurrent lesions (33 patients) were reirradiated using this type of salvage therapy. The medical history, dose-volume histogram parameters, complications, local control, overall survival (OS), and affected factors were analyzed.

All patients were followed-up until expiration, and the median duration of follow-up was 16 months. The 1-, 3-, 6-, 12-, and 18-month local control rates were 84.5%, 74.2%, 60.0%, 55.5%, and 33.3%, respectively. The symptoms significantly improved after implantation. The median local tumor progression-free survival (LTPFS) and OS times were 7 months (range, 1-19 months) and 12 months (range, 2-42 months), respectively. The 1- and 2-year OS rates were 65.5% and 43.6%, respectively. In univariate analysis, a good performance status, a tumor diameter <4 cm, an interval time from last radiotherapy to seed implantation longer than 6 months and D90 (dose delivered to 90% of the target volume) ≥130 Gy were prognostic factors for LTPFS. Cox proportional hazards regression analysis revealed that tumor size and D90 were independent factors affecting LTPFS (P=0.033, hazard ratio [HR] =3.357, 95% CI =1.105, 10.212; P=0.035, HR =2.766, 95% CI =1.072, 10.212). Good performance status was identified as an independent factor affecting OS (P=0.001, HR =0.086, 95% CI =0.019, 0.387). Two patients showed grade 3-4 toxicity - 1 patient had rectovaginal fistula and 1 patient had incomplete intestinal obstruction - and 3 cases showed seed migration in our analysis. No grade 5 events occurred.

Reirradiation with CT-guided ¹²⁵I seed interstitial brachytherapy is a safe, effective, and minimally invasive method to treat patients with recurrent cervical cancer after radiotherapy.