Outpatient-based high-dose-rate interstitial brachytherapy for gynecologic malignancies

Area of Science:

• Gynecologic Oncology
• Radiation Oncology
• Medical Physics

Background:

• Gynecologic malignancies pose significant treatment challenges.
• High-dose-rate (HDR) interstitial brachytherapy (ISBT) is an established modality for gynecologic cancers.
• Evaluating outpatient-based HDR-ISBT is crucial for optimizing patient care and resource utilization.

Purpose of the Study:

• To assess the feasibility, safety, and efficacy of outpatient-based high-dose-rate (HDR) interstitial brachytherapy (ISBT) for treating gynecologic malignancies.
• To compare toxicity and local control rates with historical outcomes.

Main Methods:

• A prospective study of 50 patients with gynecologic cancers (vaginal, vulvar, urethral, cervical) treated with twice-daily outpatient HDR-ISBT (iridium-192) between December 2006 and July 2012.
• Patients received definitive, recurrent, postoperative, or palliative treatment, often combined with external beam radiation therapy and/or chemotherapy.
• Dosimetry and complication rates were analyzed, with a focus on factors influencing outcomes.

Main Results:

• Median follow-up was 13.7 months. Median interstitial dose was 18 Gy (2.25 Gy/fraction, twice daily).
• Actuarial local control at 1 year was 72%. Non-endometrioid adenocarcinomas showed worse local control than squamous cell carcinoma (20% vs. 84%, p=0.044).
• 16% of patients required emergency room visits or hospitalization; 17% experienced significant complications, with larger treatment volumes correlating with complications (p=0.039).

Conclusions:

• Outpatient-based HDR-ISBT is a feasible and safe treatment option for gynecologic malignancies.
• Toxicity and local control rates achieved in this outpatient setting are comparable to those reported in historical, inpatient-based studies.
• This approach offers a viable alternative for managing gynecologic cancers, potentially improving patient convenience and healthcare efficiency.