The results of radiotherapy for isolated elevation of serum PSA levels following radical prostatectomy

Eleven patients were initially treated for localized prostate cancer with radical retropubic prostatectomy following negative pelvic lymph node dissection. Six or more months after surgery, these patients had elevated serum prostate specific antigen (PSA) levels. No patient had other clinical evidence of disease as determined by history, physical examination, bone scan, computed tomographic scan of the abdomen and pelvis, chest radiograph, complete blood cell count, and serum chemistry profile. These patients received prostate bed irradiation using 10-MV photons and a four-field technique. Doses ranged from 60.0 to 65.8 Gy in 1.8 to 2.0 Gy fractions. Levels of serum PSA were monitored and decreased initially in all treated patients. In two patients, levels of PSA increased after this initial decrease. In 7 of the 11 patients (64%), PSA levels decreased to ≤ 0.3 ng/mL at last measurement. Radiotherapy resulted in no severe toxicity. None of the patients had developed clinical evidence of disease at the time of this report. Isolated elevations of serum PSA after prostatectomy reflect residual disease, and radiotherapy appears to effectively decrease the PSA levels in most cases. This effect appears to be accomplished by killing locally residual or recurrent cancer in the postoperative tumor bed.