THE USE OF PROSTATE-SPECIFIC ANTIGEN (PSA) FOR THE MONITORING OF RADIATION-THERAPY IN PROSTATE-CANCER

Background: The classic methods for surveilling the efficacy of radiot herapy in prostate cancer are not accurate enough. The objective of th is analysis was to determine whether prostate-specific antigen could p erform this task. Materials and methods: From 1/95 to 10/95, 16 patien ts were treated at our clinic. 7 of these underwent primary irradiatio n 4 treatment for local recurrence and 5 had adjuvant radiotherapy. Ra diotherapy was carried out with a total dose of 60 Gy in 30 fractions, IO fractions per week, to the prostate bed plus 2 cm safety margin. R esults: PSA levels usually start to decline between the 3rd and the 4t h week of radiotherapy with a half-life of 2.5 months. Five patients h ad equal or rising PSA levels, including all three patients with recur rent tumor. Discussion: In most cases, PSA declined continuously from the 3rd week of therapy. Our median half-life was similar to other rep orted results. Persisting or rising PSA levels are an indicator for lo cal or distant recurrence; all our patients who developed a recurrence showed a corresponding PSA increase.