SPERMATOGENESIS AFTER FRACTIONATED, LOW-DOSE IRRADIATION OF THE GONADS

  • 1 January 1982
    • journal article
    • review article
    • Vol. 158  (6) , 342-355
Abstract
Fifty-eight patients (50 retrospectively, 8 prospectively) who received postoperative radiotherapy for seminoma constitute the patient population with which the tolerance dosage for spermatogenesis following low-dose fractionated radiation of the gonads was determined. Field arrangement and caudal field limit were the parameters which determined the amount of the dose to the gonads. Total doses of < 100 cGy [centigray], with daily doses of 3-5 cGy, permit a complete recovery of spermatogenesis within 14-22 mo. The occurrence of azoospermia can be expected 3-5 mo. after initiation of irradiation, lasting for 5-6 mo. Doses of > 100-150 cGy permit only partial recovery of spermatogenesis; doses of > 150 cGy can lead to permanent azoospermia. In the absence of evidence of mobile spermatozoa in the ejaculate > 2 yr after radiotherapy, no repopulation of the seminiferous tubules can be expected. After receiving ionizing radiation the stem cells of the spermatogonia have only a very limited capability for repair, regeneration and compensation; this is the reason for the very high sensitivity of spermatogenesis to low-dose fractionated radiation of the male gonads.