Testicular Function After Radioiodine Therapy in Patients with Thyroid Cancer

Abstract

Our aim was to assess testicular function in patients treated with high-dose radioiodine. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels were determined in 52 men with thyroid carcinoma before and 6, 12, and 18 months after radioiodine therapy (3.7-5.5 GBq 131 I; mean, 4.25 GBq 131 I) (group 1) and were also determined before and 18 months after the last radioiodine therapy in 22 patients who received high cumulative activities (13-27.7 GBq; mean, 20.3 GBq 131 I) (group 2). FSH levels were increased 6 months after therapy in all patients of group 1, while a decline was observed after 12 months, with 37 of 52 (71%) subjects presenting normal values. FSH values returned to normal after 18 months in all patients. In group 2, 12 of 22 (54.5%) patients presented elevated FSH and 8 (66%) of these individuals had oligospermia. Six months after radioiodine, increased LH levels were observed in only 5 of 52 (9.6%) patients of group 1, which returned to normal after 12 months, and in 5 of 22 (22%) of group 2. All patients showed normal testosterone levels. We conclude that 131 I therapy may cause impairment of testicular function. A generally transient increase in FSH is highly common but is usually reversed within 18 months. Oligospermia was common (one third) after high cumulative 131 I activities. Becausee we did not perform a spermiogram before therapy, we cannot state that high cumulative 131 I activities cause permanent infertility. We recommend the routine use of sperm banks in the cases of men who still wish to have children and who will undergo therapy with 131 I activities of 14 GBq or more or in the case of patients with pelvic metastases. 667

Preparation with Recombinant Human Thyroid-Stimulating Hormone for Thyroid Remnant Ablation with 131I Is Associated with Lowered Radiotoxicity

“…In contrast, not all investigators have confirmed the benefit of adjuvant therapy with 131 I in this group (2), with this therapy resulting in 2 relevant problems, the need for iatrogenic hypothyroidism (11) and radioiodine toxicity (1,(3)(4)(5)(6)(7)(8)(9)(10). With respect to the latter, a low activity (1.1-1.85 GBq ) is applied to minimize the adverse effects of radioiodine.…”

“…Factors against routine postoperative ablation are the uncertainty regarding the benefit for low-risk patients (2) and the undesired effects of this procedure. Rapidly occurring (weeks) and intense (low thyroxine) hypothyroidism has been inevitable until recently for ablation with 131 I, and although well tolerated, adverse effects of radioiodine, such as damage to the salivary glands (3)(4)(5), impaired gonadal function (6)(7)(8)(9), oxidative injury (10), and even the risk of a secondary neoplasm (1), have been documented. The consequences of iatrogenic hypothyroidism (11) and adverse effects of 131 I may equal or even exceed the eventual benefits of ablation, particularly in lowrisk patients (1,2,12).…”

Radioiodine Therapy: Review of the Empiric Fixed Dose Approaches and Their Selective Applications

“…Acute 33%, persistent 42% 1 year later 38,39,48) Prevention: IV amifostine, [40][41][42][43] Recommend sperm banking 39,52) Rare, 39) transient amenorrhea 17%…”

Nódulos de tireóide e câncer diferenciado de tireóide: consenso brasileiro

“…Por outro lado, o radioiodo tem sido associado a complicações como alterações transitórias da função gonadal (85,86), menopausa precoce (87), dano permanente às glân-dulas salivares e conjuntivite recorrente (88), além do risco potencial de um novo câncer (89). Todos estes aspectos devem ser considerados na definição da terapia adjuvante com 131 I após a cirurgia.…”

“…Em adultos jovens com câncer diferenciado de tiróide tratados com 131 I, tem-se observado hipospermia transitória (180), embora usualmente não apresentem alterações permanentes ao epitélio germinativo e risco de infertilidade (181). Doses cumulativas de 131 I, entre 500 e 800 mCi, podem se acompanhar de azoospermia (85). Nestes casos, aconselha-se o armazenamento de esperma em banco apropriado.…”