Session Item

to report clinical outcomes and side effect of CT-based image-guided combined high-dose-rate intracavitary and interstitial (IC/IS)  brachytherapy

A total of 341 patients with FIGO stage IB1 to IVA were treated with chemoradiation and high-dose-rate brachytherapy between 2014 and 2022. Computed tomography (CT) and/or magnetic resonance imaging (MRI) were done at baseline and before brachytherapy to plan implantation. The main applicators were Vienna-ring, Fletcher and Venezia applicators. Patients with bulky tumor (≥4cm), parametrial extension and lower vaginal involvement were selected to IC/IS brachytherapy. Target delineation defined by the GEC-ESTRO guideline with prescribed doses of 6 to 8 Gy in 4-6 fractions.

The median follow-up time was 22 months (range 1 -85). Median clinical tumor at diagnosis was 5 cm. The FIGO stage IIB and IIIB were found 46.3% and 41.1%, respectively.Complete response rate was 66.3%. IC/IS brachytherapy and MRI before brachytherapy were used 44% and 50.7%, respectively. The Vienna ring applicator was used 47.2%. IC/IS was correlated with D90 HRCTV > 85 Gy in EQD2 (p=0.003). Median doses of D90 HR-CTV, D90 IR-CTV, D2cc bladder, D2cc rectum, D2cc sigmoid and D2cc bowel were 89, 65.1, 75.95, 67.5, 62.2 and 60.9 Gy in EQD2, respectively. Cervix and pelvic recurrent were 2.9% and 8.5%, respectively but distant metastasis was 23.5%. Late grade 3 proctitis and cystitis were 1.5% and 0.3%, respectively.

CT-based intracavitary and interstitial brachytherapy is feasible and achieved effective dose coverage which provides good local control with acceptable toxicity. However MRI-based brachytherapy is increasingly used, education and long term follow-up should be practice in the treatment of cervical cancer.