Endocrine Abstracts

Background: Hypopituitarism after cranial radiotherapy for non-pituitary tumors is well recognized. However structured endocrine assessments are not incorporated into routine clinical practice

Aim of the study: To evaluate pituitary function in adult patients irradiated for non-pituitary tumors at our center

Patients and Methods: Cross-sectional evaluation of pituitary function of all available patients treated with irradiation at our center for non-pituitary cerebral or nasopharyngeal tumors and hematological malignancies

Results: 497 patients were identified from the archives of Radiotherapy and Endocrinology. Of these, 60 patients(12%) had been subjected to endocrine testing. 392 were excluded for evaluation. 231 were diseased, 102 had progressive disease, 26 did not meet inclusion criteria, 13 were unavailable and 20 declined evaluation. A total of 105 patients were eligible for this study. 63 treated for cerebral tumors, 15 for nasopharyngeal tumors, 25 for hematological malignancies, and two for cerebral metastasis. Median age at radiotherapy was 29(2–74) years and median radiation dose 54 (6–74) Gy. Median follow-up was 11.5 years (0.5–38). Endocrine evaluation included morning hormonesampling and ITT (n=63), metyrapone(n=4), CRH (n=26), ACTH (n=15), or GHRH/Arginine (n=19). Any hypopituitarism was present in 51/105(48.6%) of cases. The prevalence of GHD was 29%. ACTH-deficiency in 25%, TSH-deficiency in 16% and LH/FSH-deficiency in 20%. Hyperprolactinemia was present in 25%. A higher irradiation dose (>25 Gy) was associated with a significantly higher prevalence of hypopituitarism. The mean period of onset of pituitary insufficiency was 4.5 years (0.5–35) for GH deficiency, 3 (1–16)years for TSH deficiency, HPA-axis after 6 years (0–24) and FSH/LH insufficiency after 7 years (0–16). Hyperprolactinemia occurred after approximately 2.5 years (0–21) years.

Conclusion: After long-term follow-up, hypopituitarism is highly prevalent in adult patients after cranial radiotherapy for non-pituitary tumors, but only 12% of patients at our center was subjected to endocrine testing. Periodical endocrine evaluation should be incorporated in the follow-up of all patients treated by cranial radiotherapy.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.