Larry B. Levy, MS

The introduction of prostate-specific antigen (PSA) as a reliabletumor marker for prostate cancer brought significant changes in theend points used for outcome reporting after therapy. With regard to adefinition of failure after radiation, a consensus was reached in 1996that took into account the particular issues of an intact prostate aftertherapy. Over the next several years, the consensus definition issued bythe American Society for Therapeutic Radiology and Oncology(ASTRO) was used and studied. Concerns and criticisms were raised.The sensitivity and specificity of this definition vs other proposals hasbeen investigated, and differences in outcome analyzed and compared.Although the ASTRO definition came from analysis of datasets on external-beam radiation and most of the work on this topic has been withthis modality, failure definitions for brachytherapy must be exploredas well. The concept of a universal definition of failure that might beapplied to multiple modalities, including surgery, should also be investigated,at least for comparative study and research purposes.