ATTEMPTED PROTECTION OF SPERMATOGENESIS FROM IRRADIATION IN PATIENTS WITH SEMINOMA BY D-TRYPTOPHAN-6 LUTEINIZING-HORMONE-RELEASING HORMONE

Possible protective effects of D-Tryptophan-6 luteinizing hormone rele asing hormone (D-Trp-6-LH-RH) against irradiation-induced testicular d amage were investigated for the first time in patients with seminoma. After unilateral orchiectomy 12 men were allocated to receive the long -acting gonadotropin releasing hormone (GnRH) agonist D-Trp-6-LH-RH pr ior to and for the duration of radiotherapy. Eight patients with the s ame disease served as a control group. In contrast to several trials t o protect spermatogenesis from chemotherapy by GnRH agonists, we first suppressed the pituitary-testicular axis before starting the treatmen t. As a new schedule this adjuvant GnRH agonist treatment was combined with cyproterone acetate for the first 20 days to diminish the amount and the duration of the initial stimulation of gonadotropins and test osterone. Irradiation started after suppression of the pituitary-gonad al axis. In all patients luteinizing hormone and testosterone were com pletely suppressed throughout the treatment compared to the controls, whereas the initial suppression of follicle-stimulating hormone was no t completely maintained until radiotherapy was completed. At the follo w-up at 18 months after completion of therapy, all patients reached th eir initial concentration of gonadotropins, testosterone, and motile s permatozoa independently of D-Trp-6-LH-RH treatment. With the dose and schedule investigated, the GnRH agonist showed no protective effects against testicular damage caused by radiotherapy.