Testosterone production is better preserved after 16 than 20 Gray irradiation treatment against testicular carcinoma in situ cells.
OBJECTIVE
To study the effect of 16 Gy radiotherapy (RT) vs. 20 Gy RT on Leydig cell function in men treated with radiotherapy against carcinoma in situ (CIS) of the testis.


METHODS
Fifty-one men who were treated between 1985 and 2005 were included. Fourteen men had been treated with 20 Gy and 37 with 16 Gy RT. Measurements of sex hormone-binding globulin and basic and stimulated testosterone, as well as luteinizing hormone levels were performed.


RESULTS
The follow-up periods for the patients treated without additional chemotherapy were for the 20 Gy and 16 Gy group mean/median/min-max: 9.0/10.0/1.0-20.3 years and 4.0/3.1/0.4-14.1 years, respectively. During the follow-up period, men treated with 16 Gy RT had stable testosterone levels (-1.1%/year, p = 0.4), whereas men treated with 20 Gy had an annual decrease of 2.4% (p = 0.008). For the latter group, the testosterone decrease was most pronounced in the first 5 years, leveling off during the following 5 years. Additionally, more men treated with 20 Gy needed androgen substitution treatment. Our study showed an increased luteinizing hormone level for the men treated with 16 Gy, although this was not significant (p = 0.5). We anticipated a similar increase in the patients treated with 20 Gy but instead observed a decrease (-3.1%, p = 0.01).


CONCLUSIONS
RT at 16 and 20 Gy seem to affect Leydig cell function differently, with 16 Gy RT better preserving testosterone levels and thus being preferred from an endocrinological point of view.
Bang
Anne K
AK
University Department of Growth and Reproduction, Rigshospitalet, Blegdamsvej 9, Copenhagen, Denmark.
Petersen
Jørgen H
JH
Petersen
Peter M
PM
Andersson
Anna-Maria
AM
Daugaard
Gedske
G
Jørgensen
Niels
N
D000328:Adult; D002278:Carcinoma in Situ / Q000378:metabolism / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007985:Leydig Cells / Q000378:metabolism / Q000528:radiation effects*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D009919:Orchiectomy; D011446:Prospective Studies; D013736:Testicular Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000532:radiotherapy* / Q000601:surgery; D013739:Testosterone / Q000096:biosynthesis* / Q000097:blood; D013997:Time Factors
D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone