Long-term biochemical outcomes using cesium-131 in prostate brachytherapy

Area of Science:

• Oncology
• Radiation Oncology
• Urology

Background:

• Low-dose-rate (LDR) brachytherapy (BT) provides equivalent biochemical outcomes to radical prostatectomy and external-beam radiotherapy for prostate cancer.
• Iodine-125 (¹²⁵I) is a common isotope but may lead to long-term urinary issues.
• Cesium-131 (¹³¹Cs) offers a higher dose rate and shorter delivery time, potentially reducing urinary morbidity.

Purpose of the Study:

• To report a high-volume institutional experience with ¹³¹Cs prostate brachytherapy.
• To present the most mature long-term outcome data for ¹³¹Cs in managing prostate cancer.
• To evaluate the efficacy and safety of ¹³¹Cs compared to other brachytherapy isotopes.

Main Methods:

• A retrospective analysis of 571 men with low-, intermediate-, and high-risk prostate cancer treated with ¹³¹Cs monobrachytherapy, dual, or trimodality therapy.
• Risk stratification based on National Comprehensive Cancer Network guidelines.
• Median follow-up of 5 years, with assessment of overall survival, freedom from biochemical failure, and prostate cancer-specific survival.

Main Results:

• Excellent 5/7-year survival rates across all risk groups (overall survival: 87.1%-96.9%; biochemical failure-free survival: 74.5%-98.5%; cancer-specific survival: 98.0%-100%).
• Statistically significant differences in outcomes were observed between risk groups (p < 0.02).
• Long-term outcomes demonstrated robust disease control and survival comparable to ¹²⁵I and Palladium-103 (¹⁰³Pd).

Conclusions:

• ¹³¹Cs is a viable and effective alternative isotope for prostate brachytherapy in organ-confined disease.
• Long-term biochemical control and survival outcomes with ¹³¹Cs are excellent and comparable to ¹²⁵I and ¹⁰³Pd.
• The findings support the continued use of ¹³¹Cs as a comparable and effective option for prostate cancer brachytherapy.