MRI-Guided Multi-Catheter High-Dose-Rate Interstitial Brachytherapy for Uterine Cervical Cancer

Background/Objectives To evaluate the efficacy and safety of unique magnetic resonance imaging (MRI)-guided interstitial brachytherapy (ISBT) for locally advanced cervical cancer that is unsuitable for intracavitary brachytherapy (ICBT) or intracavitary/interstitial brachytherapy (ICISBT). Methods: We analyzed the clinical outcomes, including toxicity, of 68 previously untreated patients with cervical cancer treated between 2014 and 2024. Results: The median high-risk clinical target volume (HR-CTV) was 53.20 cc (range, 16.34-147.03 cc) with ISBT. With a median follow-up time of 37.5 months (7-115 months), the three-year local control, progression-free survival, and overall survival rates were 89.8%, 52.4%, and 70.9%, respectively. Multivariate analyses showed significant associations of histology with local control, overall treatment times, HR-CTV volume with overall survival rate, over all treatment times, and HR-CTV volume and M category with progression-free survival. Toxicity grade 3 occurred in 12 patients (17.6%) and consisted of four genitourinary (5.8%) and seven gastrointestinal (10.2%) toxicities. Conclusions: MRI-guided ISBT is an effective treatment strategy for obtaining a favorable local control rate for selected advanced diseases with an acceptable complication rate. Future research is warranted to elucidate who would be good candidates for MRI-guided ISBT.