TESTICULAR DAMAGE AFTER RADIOACTIVE IODINE (I‐131) THERAPY FOR THYROID CANCER

Abstract

Testicular damage was evaluated in 12 men by determination of sperm counts, serum FSH, lutropin and testosterone up to 3.5 yr after treatment with radioactive iodine (131I) therapy for thyroid cancer. Dose-dependent spermatogenic damage with elevation of serum FSH was evident. Full recovery in one and partial recovery in another patient was documented during 2.5 yr of follow-up. Serial study in 2 patients documented a small but significant effect of 50 mCi131I on serum FSH levels and clinically important effects appear to be restricted to men having multiple doses totalling over 100 mCi.