Image-guided adaptive interventional radiotherapy (modern brachytherapy) boost for vaginal recurrences

Area of Science:

• Oncology
• Radiation Oncology
• Gynecologic Oncology

Background:

• Vaginal recurrences pose a significant challenge in gynecologic cancer treatment.
• Evaluating outcomes of radiotherapy with or without chemotherapy followed by image-guided interventional radiotherapy (IG-IRT) is crucial.

Purpose of the Study:

• To assess the clinical outcomes of patients with vaginal recurrences treated with external beam radiotherapy (EBRT) plus chemotherapy, followed by IG-IRT.
• To determine the efficacy and safety of IG-IRT as a boost for vaginal cuff recurrences.

Main Methods:

• Retrospective analysis of 32 patients with vaginal recurrences treated with EBRT ± chemotherapy and endovaginal high dose rate IG-IRT.
• EBRT dose: 45 Gy; IG-IRT boost: 28 Gy in 4 fractions, achieving 85-95 Gy EQD2 (HR-CTV) and 60 Gy EQD2 (IR-CTV).
• Primary endpoint: local control. Secondary endpoints: survival rates and toxicity.

Main Results:

• Excellent 2-year local control (100%), metastasis-free survival (77.8%), overall survival (93%), and cancer-specific survival (93%).
• Chemotherapy, particularly cisplatin-based, significantly reduced metastasis risk (p=0.0038; 5% with cisplatin).
• Age > 59 years was linked to increased mortality (p=0.026), confirmed as an independent predictor (p<0.05).
• Low toxicity: 2 patients with acute GI/skin toxicity, 1 with late vaginal stenosis.

Conclusions:

• Image-guided interventional radiotherapy (IG-IRT) boost after EBRT is effective and safe for vaginal cuff recurrences.
• This treatment provides excellent local control and a favorable toxicity profile.
• Chemotherapy and patient age are important prognostic factors.