Radiation
therapy as a treatment for prostate cancer is becoming more widely used. Up to
one-third of all patients with prostate cancer are now treated with radiation
therapy, rather than radical
pro state surgery. Many types of radiation therapy are now available,
and the best method is not yet determined. What also remains unclear is how low
the PSA
tests after radiation therapy should go to constit ute a treatment success.
In a new study by Frank Critz, from the Dekalb
Medical Center of Atlanta, Georgia, the PSA values were followed in 536 men with
prostate cancer were treated with radioactive iodine implants followed by
conventional external x-ray radiation. In the men who achieved a lowest PSA
level below 0.5 had a 95% 5-year survival and a 84% 10-year survival, compared
to only 29% 5-year survival in men whose PSA remained above 0.5. He concluded
that for radiation therapy to be successful the P SA level must become below
0.5, meaning that all malignant
prostate tissue in the body is removed. This study
confirms the value of PSA tests following radiation therapy for prostate cancer,
but suggests it must be monitored closely.
