Prediction of Long-term Post-operative Testosterone Replacement Requirement Based on the Pre-operative Tumor Volume and Testosterone Level in Pituitary Macroadenoma

Cheng-Chi Lee,Chung-Ming Chen,Chi-Cheng Chuang,Ping-Ching Pai,Shih-Tseng Lee,Kuo-Chen Wei,Cheng-Hong Toh

doi:10.1038/srep16194

Abstract

Non-functioning pituitary macroadenomas (NFPAs) are the most prevalent pituitary macroadenomas. One common symptom of NFPA is hypogonadism, which may require long-term hormone replacement. This study was designed to clarify the association between the pre-operative tumor volume, pre-operative testosterone level, intraoperative resection status and the need of long-term post-operative testosterone replacement. Between 2004 and 2012, 45 male patients with NFPAs were enrolled in this prospective study. All patients underwent transsphenoidal surgery. Hypogonadism was defined as total serum testosterone levels of <2.4 ng/mL. The tumor volume was calculated based on the pre- and post-operative magnetic resonance images. We prescribed testosterone to patients with defined hypogonadism or clinical symptoms of hypogonadism. Hormone replacement for longer than 1 year was considered as long-term therapy. The need for long-term post-operative testosterone replacement was significantly associated with larger pre-operative tumor volume (p = 0.0067), and lower pre-operative testosterone level (p = 0.0101). There was no significant difference between the gross total tumor resection and subtotal resection groups (p = 0.1059). The pre-operative tumor volume and testosterone level impact post-operative hypogonadism. By measuring the tumor volume and the testosterone level and by performing adequate tumor resection, surgeons will be able to predict post-operative hypogonadism and the need for long-term hormone replacement.

Highlights

Dekkers et al have reported that, in patients presenting with hypopituitarism, growth hormone (GH) deficiency and gonadal deficiency are observed in approximately 85% and 75% of all patients, respectively; alternatively, corticotroph and thyrotroph deficiencies are observed less frequently[1,2,3,4,5,6,7,8]
Permanent impairment of pituitary endocrine function has been reported to be caused by tumors, apoplexy, or surgical manipulations, surgery remains the treatment of choice for Non-functioning pituitary macroadenomas (NFPAs)
Between 2004 and 2012, 45 male patients with NFPAs underwent a total of 52 operations; 7 patients underwent a second operation because of residual tumor progression

Summary

Introduction

Dekkers et al have reported that, in patients presenting with hypopituitarism, growth hormone (GH) deficiency and gonadal deficiency are observed in approximately 85% and 75% of all patients, respectively; alternatively, corticotroph (approximately 38%) and thyrotroph (approximately 32%) deficiencies are observed less frequently[1,2,3,4,5,6,7,8]. Permanent impairment of pituitary endocrine function has been reported to be caused by tumors, apoplexy, or surgical manipulations, surgery remains the treatment of choice for NFPAs. relieving the pressure on the normal pituitary may promote post-operative recovery from hypopituitarism. Whether the pre-operative tumor volume or intraoperative resection ratio significantly impacts post-operative hormone deficiency and whether long-term supplementation is needed warrant further investigation. To clarify the impact of the tumor volume and resection ratio on hypogonadism, we sought to quantify this correlation by calculating the most accurate pre- and post-operative NFPA volume by using a more accurate method. The aim of this study was to assess the relationship between the pre-operative tumor volume, the resection/residual ratio, and hypogonadism and, if possible, to predict the necessity of long-term hormone replacement

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Discussion

Conclusion