Inhibin B and anti-Müllerian hormone as markers of gonadal function after treatment for medulloblastoma or posterior fossa ependymoma during childhood.

ABSTRACT

OBJECTIVE: To evaluate the roles of hypothalamic-pituitary and spinal irradiations and chemotherapy in gonadal deficiency after treatment for medulloblastoma or posterior fossa ependymoma by measuring levels of plasma inhibin B and antimüllerian hormone (AMH). STUDY DESIGN: A total of 34 boys and 22 girls were classified as having normal levels of plasma follicle-stimulating hormone (FSH; <9 IU/L), or abnormal levels of FSH (>9 IU/L) and luteinizing hormone (LH; <5 or >5 IUL). RESULTS: Two boys had partial gonadotropin deficiency, combined with testicular deficiency in one boy. Six boys had increased levels of FSH, indicating tubular deficiency, combined with Leydig cell deficiency in 5 boys. The 7 boys with inhibin B levels <100 ng/mL included the one with combined deficiencies and the 6 with testicular deficiency. Puberty did not progress in 7 girls; 3 had gonadotropin deficiency, combined with ovarian deficiency in one, and 4 had increased FSH levels, indicating ovarian deficiency. Inhibin B and AMH levels were low in the girl with combined deficiencies, in the 4 girls with ovarian deficiency, and in 4 girls with normal clinical-biological ovarian function, including 2 who underwent ovarian transposition before irradiation. CONCLUSION: The plasma concentrations of inhibin B and AMH are useful means of detecting primary gonad deficiency in patients with no increase in their plasma gonadotropin levels because of radiation-induced gonadotropin deficiency.