Clinical outcome of combined intracavitary / interstitial brachytherapy using a hybrid applicator in locally advanced cervical cancer.

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the clinical outcome in locally advanced cervical cancer (LACC) after image-guided adaptive brachytherapy (IGABT) with combined intracavitary and interstitial (IC/IS) techniques using the hybrid Venezia applicator (Elekta AB, Sweden). METHODS: LACC patients (UICC Stage IIB - IVB) treated with radiochemotherapy followed by IGABT with the hybrid IC/IS Venezia applicator at a single institution were retrospectively analyzed. Treatment comprised EBRT of the pelvis with 45 Gy and concomitant weekly cisplatin chemotherapy (40 mg/m2) followed by MRI-based IGABT. Dosimetry, oncological outcome and toxicity were investigated. RESULTS: Forty-six patients underwent a total of 184 fractions of IGABT between 2017 and 2020. Median follow-up was 24 months. Combined IC/IS techniques were used in 40 patients (87%). The median HRCTV volume was 31.2 cm3 and the median HRCTV D90% was 92.3 Gy (EQD210). The median D2cm3 was 74.8 Gy for bladder, 57.9 Gy for rectum, 60.0 Gy for sigmoid and 52.2 Gy for bowel (EQD23). The 3-yr actuarial rates were 97.6% for local control, 97.6% for pelvic control, 59.9% for distant metastasis-free survival and 81.6% for overall survival. The crude rate for G2 and G3 late toxicity was 21.7% and 4.3%. CONCLUSIONS: IGABT with the hybrid Venezia applicator and a pronounced use of a combined IC/IS technique achieved high target doses, while maintaining low doses to organs at risk, leading to excellent local control and overall survival rates with acceptable toxicity.