Hypogonadism following prostate-bed radiation therapy for prostate carcinoma

BACKGROUND. The degree of testicular damage resulting from primary treatmen t of prostate carcinoma by external beam radiation therapy (EBRT) to the pr ostate bed has not been determined. If significant testicular damage has oc curred, the resulting endocrine changes may result in modified tumor behavi or, contribute to postradiation impotence, and may aggravate other signs an d symptoms of hypogonadism, potentially influencing a patient's choice of p rimary treatment for his tumor. METHOD. Three to eight years after primary treatment for localized prostate carcinoma, serologic evaluation for hypogonadism was undertaken in 33 men who had received EBRT and in 55 similar men who had received radical prosta tectomy (RP). No subjects had developed recognized tumor recurrence, and no ne had undergone hormonal treatment since primary therapy. RESULTS. Among men of similar age, prior treatment with EBRT was associated with significantly more frequent hypogonadism than prior treatment with RP . In men with EBRT, total testosterone levels averaged 27.3% less, free tes tosterone levels 31.6% less. dihydrotestosterone levels 33.4% less, luteini zing hormone (LH) levels 52.7% greater, and follicle-stimulating hormone (F SH) levels 100% greater than those values in men who had prior treatment wi th RP. Differences between postradiation and postsurgical men in LH and FSH levers were most prominent in men older than 70 years. CONCLUSIONS. Three to eight pears after primary treatment for prostate carc inoma, striking hormone differences were present between men who had receiv ed EBRT to the prostate bed and those with prior RP. These differences stro ngly suggested that prominent and permanent testicular damage was sustained during EBRT, frequently severe enough to cause hypogonadism. (C) 2001 Amer ican Cancer Society.