A PSA of < 0.1 ng/ml is a good number. However, you don’t know if that < 0.1 ng/mL might be a 0.01 ng/mL or a 0.001 ng/mL because the test equipment they’re using isn’t sensitive enough to test that low. (The cancer center that I go to tests down to 0.008.)

Following any treatment, you’d really want to know how low it really is. You should ask your doctor about this.