tokens: OBJECTIVES : To assess the ability of pretreatment and post-treatment prostate specific antigen ( PSA ) measurements , clinical tumor stage , tumor grade , Gleason sum , race , age , and radiation dose to predict the recurrence of prostate cancer following external beam radiation therapy ( XRT ) since the introduction of PSA as a tumor marker at one tertiary care center .
folded_tokens: objective : to assess the ability of pretreatment and post-treatment prostate specific antigen ( psa ) measurement , clinical tumor stage , tumor grade , gleason sum , race , age , and radiation dose to predict the recurrence of prostate cancer follow external beam radiation therapy ( xrt ) since the introduction of psa as a tumor marker at one tertiary care center .