Outcomes after prostate brachytherapy are even better than predicted.

Area of Science:

• Urology
• Oncology
• Medical Imaging

Background:

• Benign prostate-specific antigen (PSA) bounces post-treatment can be mistaken for biochemical recurrence.
• This misdiagnosis can lead to unnecessary interventions and inaccurate outcome predictions.

Purpose of the Study:

• To evaluate the accuracy of a common PSA failure definition after prostate brachytherapy.
• To assess the prostogram's ability to differentiate benign PSA fluctuations from actual recurrence.

Main Methods:

• A multinational, multi-institutional study included 1816 men treated with prostate brachytherapy.
• Failure was defined by hormone therapy use, clinical relapse, or prostogram-defined PSA failure.
• Outcomes were compared with prostogram predictions over a median follow-up of 5.2 years.

Main Results:

• The prostogram's predictive accuracy (Harrell c statistic) varied significantly across institutions (0.493-0.696).
• A mean difference of 9.2% was observed in 5-year biochemical recurrence-free survival between actual outcomes and prostogram definitions.
• Prostogram identified significantly more failures (312) than actual clinical outcomes (157).

Conclusions:

• The prostogram definition is inadequate for distinguishing benign PSA bounces from biochemical recurrence after brachytherapy.
• It cannot reliably counsel patients on predicted outcomes.
• Clinicians should monitor PSA for 3 years, reassuring patients about common PSA rises.