Defining recurrence after radiation for prostate cancer

Purpose: We reviewed prostate specific antigen (PSA) definitions of recurrence after external beam radiation for prostatic cancer and related them to the definitions used for other treatment modalities. Materials and Methods: The literature on defining recurrence after external beam radiation, brachytherapy and prostatectomy for prostate cancer was reviewed through a MEDLINE search to ensure completeness and the inclusion of all pertinent information. Results: Although the definition, which is the current standard for estimating recurrence after external beam radiation, has proved to be a reasonable measure, alternative options that are more sensitive and specific have now been defined. Similar statistical testing and comparison must also be done for other treatment modalities since the choice of failure definitions has not been evaluated nearly as thoroughly for these therapies. As much as possible, outcome reporting should be done according to the same method to ensure fairness when comparisons are made. However, inherent differences between treatment modalities and their effect on PSA production must also be considered. Conclusions: With the latest available information from patients with long-term followup PSA definitions of tumor recurrence after external beam radiation for prostatic cancer must again be reviewed in a consensus conference format. The application of a universal PSA definition of tumor recurrence across multiple treatment modalities should also be explored.