A novel "total pituitary hormone index" as an indicator of postoperative pituitary function in patients undergoing resection of pituitary adenomas

Perioperative fluctuation and overall evaluation of adenohypophyseal hormone secretion in patients with nonfunctioning pituitary adenoma

OBJECTIVE

Perioperative adenohypophyseal hormone assessment can improve therapeutic strategies and be used to evaluate the prognosis of pituitary adenomas. An individual hormone level does not entirely reflect the pituitary gland. Thus, this study aimed to analyze perioperative hormonal changes and propose a normalized method to facilitate overall assessment of the adenohypophysis.

METHODS

The authors retrospectively analyzed 89 male patients with nonfunctioning pituitary adenoma (NFPA) who underwent transsphenoidal surgery. Preoperative clinical data, imaging data, and perioperative hormone levels of the anterior pituitary gland were evaluated. Hormone values were rescaled using minimum-maximum normalization. The sum of the normalized hormone levels was defined as the total hormonal rate (THR).

RESULTS

Preoperative findings indicated correlations among different adenohypophyseal hormones. Luteinizing hormone (p = 0.62) and adrenocorticotropic hormone (p = 0.89) showed no significant changes after surgery, but growth hormone levels increased (p < 0.001). On the contrary, the levels of thyroid-stimulating hormone (p < 0.001), follicle-stimulating hormone (p = 0.02), and prolactin (p < 0.001) decreased. THR indicated a significant postoperative reduction in adenohypophyseal function (p = 0.04). Patients with postoperative hypopituitarism had significantly lower THR than those without (p = 0.003), with an area under the curve of 0.66. For NFPAs that presented with normal preoperative hormone levels, THR was a good clinical predictor of immediate postoperative hypopituitarism, with an area under the curve of 0.74.

CONCLUSIONS

The normalized synthesis index of hormones is a novel and clinically valuable method used to reflect adenohypophyseal secretion. Compared with individual hormones, these results indicated that THR can facilitate the analysis of general hormone levels despite various fluctuations in adenohypophyseal hormones. THR may also contribute to the effective prediction of short-term surgery-induced hypopituitarism.

Role of pituitary stalk and gland radiological status on endocrine function and outcome after endoscopic transsphenoidal surgery for non-functioning pituitary adenomas

PURPOSE

To investigate endocrine function changes after non-functioning pituitary adenomas (NFPA) transsphenoidal surgery and to search for predictors of hypopituitarism resolution and development.

METHODS

We included 117 patients with NFPA who underwent endoscopic transsphenoidal surgery from 2005 to 2019 by two neurosurgeons. Twenty-one patients were excluded because of previous pituitary surgery or radiotherapy. We assessed symptoms at diagnosis, tumour volume, tumour removal, hormonal status at diagnosis, hormonal outcomes at 2- and 12-month follow-up, and complications. Pituitary stalk and gland MRI status (visible or not) were included, and it theirs association to hormonal function was studied for the first time, to our knowledge.

RESULTS

Pituitary gland visualization was more frequent in those patients who showed a smaller number of axes affected at 12 months (p = 0.011). Pituitary stalk status showed no association to hormonal function. The hormonal normalization rate at 12 months was 13%. The endocrine improvement rate at 12 months was 16.7%. Worsening of hormonal function occurred in 19.8% of patients. Younger age was associated to hormonal improvement (p = 0.004). Higher preoperative tumour volume (p = 0.015) and absence of gross total resection (GTR) (p = 0.049) were associated with worsening in at least one hormonal axis after surgery.

CONCLUSIONS

Pituitary gland visibility was higher in those patients who showed better hormonal outcomes. Assessment of initial hormonal function and outcome after surgery regarding pituitary stalk status showed no significant association. Higher preoperative tumour volumes and absence of GTR were associated to postoperative endocrine function worsening, while younger age was associated to its improvement.

Machine-Learning Prediction of Postoperative Pituitary Hormonal Outcomes in Nonfunctioning Pituitary Adenomas: A Multicenter Study

OBJECTIVE

No accurate predictive models were identified for hormonal prognosis in non-functioning pituitary adenoma (NFPA). This study aimed to develop machine learning (ML) models to facilitate the prognostic assessment of pituitary hormonal outcomes after surgery.

METHODS

A total of 215 male patients with NFPA, who underwent surgery in four medical centers from 2015 to 2021, were retrospectively reviewed. The data were pooled after heterogeneity assessment, and they were randomly divided into training and testing sets (172:43). Six ML models and logistic regression models were developed using six anterior pituitary hormones.

RESULTS

Only thyroid-stimulating hormone (p < 0.001), follicle-stimulating hormone (p < 0.001), and prolactin (PRL; p < 0.001) decreased significantly following surgery, whereas growth hormone (GH) (p < 0.001) increased significantly. The postoperative GH (p = 0.07) levels were slightly higher in patients with gross total resection, but the PRL (p = 0.03) level was significantly lower than that in patients with subtotal resection. The optimal model achieved area-under-the-receiver-operating-characteristic-curve values of 0.82, 0.74, and 0.85 in predicting hormonal hypofunction, new deficiency, and hormonal recovery following surgery, respectively. According to feature importance analyses, the preoperative levels of the same type and other hormones were all important in predicting postoperative individual hormonal hypofunction.

CONCLUSION

Fluctuation in anterior pituitary hormones varies with increases and decreases because of transsphenoidal surgery. The ML models could accurately predict postoperative pituitary outcomes based on preoperative anterior pituitary hormones in NFPA.

Outcome of Transsphenoidal Surgery for Cushing Disease: A Single-Center Experience over 20 Years

BACKGROUND

This study investigated the outcome of transsphenoidal surgery (TSS) for Cushing disease (CD) and the influence of our surgical strategy on remission rates and postoperative pituitary function.

PATIENTS AND METHODS

We retrospectively reviewed data from 71 patients with CD who underwent microscope navigation TSS (MN-TSS) in Saint-Luc Hospital between 1996 and 2017. True remission was defined as normal fasting cortisol level, normal 24-hour urinary free cortisol, or continued need for hydrocortisone replacement for 1 year after surgery.

RESULTS

Overall remission rate after 1 or repeated MN-TSS was 83%. Highest remission rate was found in patients with macroadenomas (92%). Successful first MN-TSS was correlated with a high final remission rate (95%), whereas failed first MN-TSS was correlated with a low final remission rate (36%). Although day 1 cortisol levels were significantly lower in patients with long-term remission, high levels were still observed in a few patients, especially those who had had CD for many years. We found a low rate of postoperative pituitary long-term hypofunction (9.7%).

CONCLUSIONS

MN-TSS is a safe and effective procedure to treat CD, allowing remission rates of 83%. One-year remission period after first surgery is correlated with a final remission rate of 95%. Although day 1 morning cortisol value is the most significant predictor for long-term remission, some patients with CD for many years may keep high postoperative cortisol levels and be in later remission, likely because of secondary adrenal hyperplasia. Our focused approach with microscope navigation resulted in low rates of postoperative pituitary hypofunction and kept a recurrence rate comparable to that in the literature.