[Machine learning methods in differential diagnosis of ACTH-dependent hypercortisolism].

AIM: To develop a noninvasive method of differential diagnosis of ACTH-dependent hypercortisolism, as well as to evaluate the effectiveness of an optimal algorithm for predicting the probability of ectopic ACTH syndrome (EAS) obtained using machine learning methods based on the analysis of clinical data. MATERIALS AND METHODS: As part of a single-center, one-stage, cohort study, a retrospective prediction of the probability of EAS among patients with ACTH-dependent hypercortisolism was carried out. Patients were randomly stratified into 2 samples: training (80%) and test (20%). Eleven machine learning algorithms were used to develop predictive models: Linear Discriminant Analysis, Logistic Regression, elastic network (GLMNET), Support Vector machine (SVM Radial), k-nearest neighbors (kNN), Naive Bayes, binary decision tree (CART), C5.0 decision tree algorithms, Bagged CART, Random Forest, Gradient Boosting (Stochastic Gradient Boosting, GBM). RESULTS: The study included 223 patients (163 women, 60 men) with ACTH-dependent hypercortisolism, of which 175 patients with Cushing's disease (CD), 48 - with EAS. As a result of preliminary data processing and selection of the most informative signs, the final variables for the classification and prediction of EAS were selected: ACTH level at 08:00 hours, potassium level (the minimum value of potassium in the active stage of the disease), 24-h urinary free cortisol, late-night serum cortisol, late-night salivary cortisol, the largest size of pituitary adenoma according to MRI of the brain. The best predictive ability in a training sample of all trained machine learning models for all three final metrics (ROC-AUC (0.867), sensitivity (90%), specificity (56.4%)) demonstrated a model of gradient boosting (Generalized Boosted Modeling, GBM). In the test sample, the AUC, sensitivity and specificity of the model in predicting EAS were 0.920; 77.8% and 97.1%, respectively. CONCLUSION: The prognostic model based on machine learning methods makes it possible to differentiate patients with EAS and CD based on basic clinical results and can be used as a primary screening of patients with ACTH-dependent hypercortisolism.

[Diagnostic value of bilateral inferior petrosal sinus sampling in various modifications and methods of radiation and radionuclide imaging in the diagnosis and differential diagnosis of ACTH-dependent endogenous hypercortisolism].

AIM: To analyze the diagnostic performance of bilateral inferior petrosal sinus sampling (BIPSS) with desmopressin as a stimulation agent and prolactin measurements to control catheter position with or without the ACTH/prolactin normalized ratio calculation in the differential diagnosis of ACTH-dependent endogenous hypercortisolism, and the diagnostics performance of ectopic ACTH-syndrome (EAS) visualization. MATERIALS AND METHODS: A single-center diagnostic study with a retrospective analysis of the data was carried out. The study included patients with ACTH-dependent endogenous hypercorticism with no visualization of pituitary adenoma on MRI or adenoma sizes less than 6 mm. All patients underwent BIPSS with and without calculation of the ACTH/prolactin normalized ratio. Visualization of an EAS included pituitary MRI (to exclude EAS), whole-body CT scan with contrast, and somatostatin receptor scintigraphy with 99mTc-Tectrotide and CT (99mTc-Tectrotide SPECT). The final verification was based on immunohistochemical confirmation of the tumor or stable remission of Cushing's disease (CD) after surgical treatment. Statistical data processing was carried out by using IBM SPSS Statistics 23. Confidence intervals were calculated using the JavaStat online calculator. RESULTS: 230 BIPSS were performed in 228 patients (166 women, 62 men), of which 178 patients were verified as CD and 50 cases were EAS of various localization. The effectiveness of catheterization of petrosal sinuses was 96.9%. The sensitivity of BIPSS without ACTH/prolactin ratio calculation (n=70) was 95.9% (95% CI 86.3-98.9), specificity was 92% (95% CI 75.0-97.8), for the BIPSS with additional determination of ACTH/prolactin-normalized ratio (n=51) - 97.3% (95% CI 86.2-99.5) and 93.8% (95% CI 71.7-98.9), respectively. The use of the MRI method for this sample of patients had a sensitivity of 60.2% (95% CI 52.6-67.5), specificity of 59.2% (95% CI 44.2-73.0), the total body CT with contrast has a sensitivity of 74% (95% CI 59.7-85.4), specificity of 100% (95% CI 97.95-100). The diagnostic accuracy for 99mTc-Tectrotide SPECT in NET visualization has a sensitivity of 73.3% (95% CI 44.9-92.2), specificity of 100% (95% CI 95.3-100). CONCLUSION: BIPSS with desmopressin stimulation and prolactin measurements to control catheter position, as well as the additional calculation of the ACTH/prolactin-normalized ratio, is an optimal method for the differential diagnosis of EAS. Patients who are identified an EAS on BIPSS may be further referred for 99mTc-Tectrotide SPECT and CT for tumor visualization.

[Survival predictors in patients with ectopic acth syndrome].

AIM: To determine significant factors affecting the survival of patients with ectopic ACTH syndrome (EAS). MATERIALS AND METHODS: A multi-center, observational study with a retrospective analysis of patients with EAS. The end point of the study was the fatal outcome of patients from various causes. In order to identify predictors of survival or mortality, univariate and multifactorial Cox regression analyses were carried out. ROC-analysis was used to determine the prognostic threshold values of individual predictors. The survival analysis was carried out using the Kaplan-Mayer method. Statistical data processing was carried out by using IBM SPSS Statistics 23. RESULTS: The age of patients at the time of diagnosis ranged from 12 to 76 years (Me 40 years [28;54]). The age of the studied population was 55 years [38; 64] for women and 42 years [32; 54] for men. The median period of observation was 50 months [13;91], with a maximum follow-up of 382 months. 92 patients (60,9%) had bronchopulmonary NET, 17 (11,3%) - thymic carcinoid, 8 - pancreatic NET, 5 -pheochromocytoma, 1- cecum NET, 1- appendix carcinoid tumor, 1 - medullary thyroid cancer and 26 (17,2%) patients had an occult NET. The primary tumor was removed in 101 patients (66,9%). Bilateral adrenalectomy was performed in 42 (27,8%) cases. Metastases were revealed in 23,2% (n=35) of patients. Relapse of the disease was observed in 24,4%, long-term remission was preserved in 64 patients (74,4%). Death occurred in 42 patients (28%). The average age of survivors was 47,0±15,2 versus 53,5±15,6 years for the deceased (p=0,022). The average survival time from diagnosis for the deceased was 32 months, Me 16,5 months [7;54]. Multivariate analysis revealed that the following factors have a direct impact on survival: age of diagnosis ≥51 years (OR 4,493; 95% CI 2,056-9,818, p<0,001), bronchopulmonary neuroendocrine tumor (NET) (OR 0,281; 95% CI 0,119-0,665, p=0,004), the presence of distant metastases (OR 2,489; 95% CI 1,141-5,427, p=0,022), late-night salivary cortisol (LNSC) ≥122,2 nmol/L (OR 2,493; 95% CI 1,014-6,128, p=0,047). CONCLUSION: The prognosis of patients with EAS is influenced by the age of diagnosis, NET localization, distant metastases and level of LNSC. The most common cause of ectopic ACTH syndrome was bronchopulmonary NET which was associated with the best survival rate.

[Endocrine late-effects and bone mineral density after combined treatment of malignant brain tumors in childhood and adolescence].

BACKGROUND: The implementation of standardized protocols for combined treatment of cancer into clinical practice inevitably leads to a long-term consequence. AIMS: To study the prevalence of endocrine disorders, to assess the prevalence and degree of decline of bone mineral density (BMD) in individuals who have undergone combined treatment of malignant brain tumors in childhood and adolescence. MATERIALS AND METHODS: A retrospective study was conducted with 59 young adults (31 men; 28 women) who have undergone surgical treatment of malignant brain tumour followed by radiation treatment (craniospinal radiation in combination with or without polychemotherapy). Group I consisted of 37 patients, who were treated between the ages of 3 and 16 years. Group II included 22 patients who received treatment between the ages of 16 and 38 years. RESULTS: GH deficiency according to the results of the insulin hypoglycemia test was diagnosed in 48 patients (81%), 22 -patients had secondary adrenal insufficiency (37%). The majority of those examined (33 patients (56%)) did not achieve the target growth. Only 5 people from I group was treated with recombinant GH. Correlation analysis demonstrates that age of treatment is the main factor affecting final growth (r=0,619, p<0,001). Many cases of hypothyroidism (n=39 (66%)) and hypogonadism (19 women; 17 men) were detected. According to the DXA, a decrease of BMD ≤-2.0 SD (Z-score) in L1-L4 was found in 35 of 59 patients (59%). The BMD in the I group was significantly lower than in patients treated at an older age (p<0.001). A moderate correlation was discovered between BMD in L1-L4 at the time of examination and the level of estradiol in women (r=0.596, p<0.05) and testosterone in men (r=0.472, p<0.05). Direct correlation between BMD and age of diagnosis was revealed (r=0.781, p<0.01). CONCLUSIONS: The results show that patients need to be monitored annually and for life after the combined treatment of malignant brain tumors in order to detect the long-term effects of the treatment. The high incidence of osteopenic conditions determines the relevance and need for early diagnosis to prevent further bone loss, reduced bone strength and the risk of fractures.

[Clinical and laboratory characteristics and results of treatment of patients with ACTH-producing neuroendocrine tumors of various localization].

AIM: To study the clinical, biochemical characteristics, treatment results and follow-up of patients with ectopic ACTH syndrome EAS (ACTH adrenocorticotropic hormone ). MATERIALS AND METHODS: A retrospective, observational, single-center study of 130 patients with EAS. Demographic information of patients, medical history, results of laboratory and instrumental investigations at the pre- and postoperative stages and follow-up of EAS were analyzed. RESULTS: The mean age at the diagnosis ranged from 12 to 74 years (Me 40 years [28; 54]). The duration of the disease from the onset of symptoms to the verification of the diagnosis varied from 2 to 168 months (Me 17.5 months [7; 46]). Eighty-one (62,3%) patients had bronchopulmonary NET, 9 thymic carcinoid, 7 pancreatic NET, 5 pheochromocytoma, 1 cecum NET, 1 appendix carcinoid tumor, 1 medullary thyroid cancer and 25 (19.2%) had an occult source of ACTH. The median follow-up period of patients was 27 months [9.75; 61.0] with a maximum follow-up of 372 months. Currently, primary tumor was removed in 82 (63.1%) patients, bilateral adrenalectomy was performed in 23 (18%) patients, in 16 of them there was an occult source of ACTH-producing NET and in 7 patients in order to control hypercortisolism after non-successful surgical treatment. Regional and distant metastases were revealed in 25 (19.2%) patients. At the time of the last observation 59 (72%) patients were exhibited a full recovery, 12 (14.6%) had relapse of the disease and 26 (20%) died from multiple organ failure (n=18), pulmonary embolism (n=4), surgical complications (n=2), disseminated intravascular coagulation syndrome (n=1) or COVID-19 (n=1). CONCLUSION: In our cohort of patients bronchopulmonary NET are the most frequent cause of EAS (62.3%). Surgical treatment leads to remission of hypercortisolism in 72% cases; the proportion of relapse (14.6%) and fatal outcome (20%) remains frequent in EAS.

[Primary hyperparathyroidism and vitamin D deficiency].

Primary hyperparathyroidism (PHPT) is the third most common endocrine disease after diabetes mellitus and thyroid pathology. Recent epidemiological and experimental data have shown that long-term maintenance of low vitamin D levels in the blood can lead to the development of hyperplastic processes in the cells of the parathyroid glands, followed by autonomous production of parathyroid hormone. In PHPT vitamin D insufficiency or deficiency according to various sources occurs with a frequency of 5377% of cases. The literature review indicates more severe disease in patients with concomitant vitamin D deficiency. The expediency of preoperative assessment of vitamin D levels in all patients with PHPT in order to minimize the risk of hypocalcemia after parathyroidectomy is discussed. This article presents the relationship between vitamin D deficiency and PHPT, as well as possible methods for correcting vitamin D deficiency in PHPT. Molecular and cellular mechanisms of the occurrence of pathological processes in the parathyroid glands under conditions of low vitamin D levels are presented.

[Differential diagnosis of normocalcemic hyperparathyroidism and idiopathic hypercalciuria on the example of clinical case].

Idiopathic hypercalciuria is a heterogeneous generalized disorder caused by various defects in calcium transport and increased urinary calcium excretion. The main etiopathogenetic factors are violations of vitamin D metabolism, changes in the sensitivity of calcitriol receptors and violations of the processes of calcium reabsorption in the proximal tubules and in the ascending knee of the Henle loop. This article presents a clinical observation of patient with idiopathic hypercalciuria, initially high levels of parathyroid hormone (PTH) in the absence of hyperparathyroidism. Therapy with thiazide diuretics allowed to achieve normalization of daily urinary calcium excretion and reducing PTH. Despite the low prevalence of idiopathic hypercalciuria, differential diagnosis of this metabolic disorder should be carried out with mandatory consideration of clinical and laboratory data, as well as with diseases that may cause increased PTH production.