Bilateral Inferior Petrosal Sinus Sampling Research Articles

Bilateral inferior petrosal sinus sampling in the differential diagnosis of ACTH-dependent Cushing's syndrome: A reappraisal.

Cushing's syndrome (CS) is a rare disorder, once exogenous causes have been excluded. However, when diagnosed, the majority of cases are adrenocorticotropic hormone (ACTH)-dependent, of which a substantial minority are due to a source outside of the pituitary, ectopic ACTH syndrome (EAS). Differentiating among pituitary-dependent CS, Cushing's disease (CD) and an ectopic source can be problematic. Because non-invasive tests in the evaluation of CS patients often lack adequate sensitivity and specificity, bilateral inferior petrosal sinus sampling (BIPSS), a minimally invasive procedure performed during the investigation of ACTH-dependent CS, can be extremely helpful. BIPSS is considered to be the gold standard for differentiating CD from the EAS. Furthermore, although such differentiation may indeed be challenging, BIPSS is itself a complex investigation, especially in recent times due to the widespread withdrawal of corticotrophin-releasing hormone and its replacement by desmopressin. We review current published data on this investigation and, in the light of this and our own experience, discuss its appropriate use in diagnostic algorithms.

Bilateral Inferior Petrosal Sinus Sampling Without Lateralization Is Less Accurate for the Diagnosis of Cushing Disease

Abstract Context During bilateral inferior petrosal sinus sampling (BIPSS), the side-to-side adrenocorticotropic hormone (ACTH) ratio, referred to as sampling lateralization, was used to predict pituitary adenoma localization. Objective To investigate the potential different diagnostic accuracy of BIPSS for differentiating Cushing disease (CD) and ectopic ACTH secretory syndrome (EAS) patients with low lateralization (inferior petrosal sinus [IPS]:IPS ≤ 1.4) and high lateralization (IPS:IPS > 1.4). Methods This single-center retrospective study (2011-2021) included (all patients had BIPSS results and confirmed pathologic diagnoses) 220 consecutive CD patients (validation set), 30 EAS patients, and 40 of the CD patients who had digital subtraction angiography (DSA) videos (discovery set). Results In the discovery set, the low-lateralization CD group (n = 11) had a higher median plasma ACTH concentration (62.2, IQR 44.7-181.0 ng/L) than the high-lateralization CD group (n = 29) (33.0, IQR 18.5-59.5, P = .013). Lower IPS to peripheral ratios were observed in the low-lateralization group during BIPSS, both before and after stimulation (P = .013 and P = .028). The sensitivity of BIPSS before stimulation in differentiating CD from EAS was lower in the low-lateralization group than the high-lateralization group (54.6% vs 93.1%, P = .003), as validated in the validation set. DSA videos revealed higher vascular area difference visible in the 2 sides of the pituitary in low lateralization (median 1.2 × 105 pixels, IQR 0.5-1.8) than the high-lateralization group (0.4 × 105 pixels, IQR 0.1-0.7, P = .008). The vascular area ratio of the 2 sides was also significantly higher in low (1.55, IQR 1.31-2.20) than high lateralization (1.19, IQR 1.07-1.35, P = .010). Conclusion Our study suggested that low lateralization in CD patients may reduce the diagnostic sensitivity of BIPSS, which might be potentially associated with peripituitary vascular anatomy.

[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].

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. 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. 230 BIPSS were performed in 228 patients (166 women, 62 men), of which 178 patients were verified as CD and 50cases 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). 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.

Subcentimeter Corticotroph Adenoma: an Evaluation of Diagnostic Elements

Cushing’s disease (CD) is an uncommon yet serious disorder, linked to increased morbidity and mortality. Diagnosis of these patients are complex, and emphasis should be placed on early detection for better management of these patients. The objective of this case report is to evaluate the diagnostic elements in the identification of a subcentimeter adrenocorticotrophic hormone (ACTH)-dependent pituitary adenoma. We report a case of a 26-year-old man who presented with extensive superficial fungal infection of the skin, unintentional weight gain, hypertension, dyslipidaemia as well as cushingoid appearance suspicious of hypercortisolism. Raised midnight plasma cortisol and 24-hour urinary cortisol levels warranted further investigation. Overnight and 48-hour low-dose dexamethasone suppression test (LDDST) were non-suppressed. Subsequent bilateral inferior petrosal sinus sampling (BIPSS) was not only efficient in differentiating pituitary from ectopic Cushing’s syndrome (CS) but was shown to be superior to magnetic resonance imaging (MRI) in lateralisation of the pituitary adenoma.

Interpetrosal sphingosine-1-phosphate ratio predicting Cushing's disease tumor laterality and remission after surgery.

Cushing's disease (CD) poses significant challenges in its treatment due to the lack of reliable biomarkers for predicting tumor localization or postoperative clinical outcomes. Sphingosine-1-phosphate (S1P) has been shown to increase cortisol biosynthesis and is regulated by adrenocorticotropic hormone (ACTH). We employed bilateral inferior petrosal sinus sampling (BIPSS), which is considered the gold standard for diagnosing pituitary sources of CD, to obtain blood samples and explore the clinical predictive value of the S1P concentration ratio in determining tumor laterality and postoperative remission. We evaluated 50 samples from 25 patients who underwent BIPSS to measure S1P levels in the inferior petrosal sinuses bilaterally. Serum S1P levels in patients with CD were significantly higher on the adenoma side of the inferior petrosal sinus than on the nonadenoma side (397.7 ± 15.4 vs. 261.9 ± 14.88; P < 0.05). The accuracy of diagnosing tumor laterality with the interpetrosal S1P and ACTH ratios and the combination of the two was 64%, 56% and 73%, respectively. The receiver operating characteristic curve analysis revealed that the combination of interpetrosal S1P and ACTH ratios, as a predictor of tumor laterality, exhibited a sensitivity of 81.82% and a specificity of 75%, with an area under the curve value of 84.09%. Moreover, we observed that a high interpetrosal S1P ratio was associated with nonremission after surgery. Correlation analyses demonstrated that the interpetrosal S1P ratio was associated with preoperative follicle-stimulating hormone (FSH), luteinizing hormone (LH), and postoperative ACTH 8 am levels (P < 0.05). Our study demonstrated a significant association between the interpetrosal S1P ratio and tumor laterality, as well as postoperative remission in CD, suggesting that the interpetrosal S1P ratio could serve as a valuable biomarker in clinical practice.

Bilateral inferior petrosal sinus sampling: validity, diagnostic accuracy in lateralization of pituitary microadenoma, and treatment in eleven patients with Cushing’s syndrome – a single-center retrospective cohort study

BackgroundThis single-center retrospective cohort study aimed to describe the findings and validity of Bilateral inferior petrosal sinus sampling (BIPSS) in the differential diagnosis of patients with ACTH-dependent Cushing’s syndrome (CS).MethodsEleven patients underwent BIPSS due to equivocal biochemical tests and imaging results. Blood samples were taken from the right inferior petrosal sinus (IPS), left IPS, and a peripheral vein before and after stimulation with desmopressin (DDAVP). ACTH and prolactin levels were measured. The diagnosis was based on the ACTH ratio between the IPS and the peripheral vein. Also, lateralization of pituitary adenoma in patients with Cushing’s disease (CD) was predicted. No significant complications were observed with BIPSS.ResultsBased on the pathology report, eight patients had CD, and three had ectopic ACTH syndrome (EAS). Unstimulated BIPSS resulted in a sensitivity of 87.5%, specificity of 100%, PPV of 100%, NPV of 75%, and accuracy of 91%. Stimulated BIPSS resulted in a sensitivity of 100%, specificity of 100%, PPV of 100%, NPV of 100%, and accuracy of 100%. However, pituitary magnetic resonance imaging (MRI) had a lower diagnostic accuracy (sensitivity:62.5%, specificity:33%, PPV:71%, NPV:25%, accuracy:54%). BIPSS accurately demonstrated pituitary adenoma lateralization in 75% of patients with CD.ConclusionsThis study suggests that BIPSS may be a reliable and low-complication technique in evaluating patients with ACTH-dependent CS who had inconclusive imaging and biochemical test results. The diagnostic accuracy is improved by DDAVP stimulation. Pituitary adenoma lateralization can be predicted with the aid of BIPSS.

SAT598 7mg-dexamethasone Suppression Test For The Differential Diagnosis Of Cushing’s Syndrome

Abstract Disclosure: D. Cuevas Ramos: None. G. Garza García: None. W. Hernández Núñez: None. F.J. Gómez Pérez: None. Introduction: Establishing the cause of Cushing’s syndrome remains challenging. Bilateral Inferior Petrosal Sinus Sampling (BIPSS) is the gold standard for distinguishing between Cushing's disease (ACHT-secreting pituitary adenoma) and an ectopic source of ACTH. However, BIPSS is an invasive test and is not widely available. Therefore, we sought to explore the diagnostic efficacy of the 7 mg dexamethasone suppression test (7mg-dexa) for establishing the diagnosis of Cushing's disease (CD). Methods: We reviewed 1375 cases with pituitary adenomas. From them, 191 cases had confirmed diagnosis of CD from 1999 to 2022. Of these, 25 patients underwent 7 mg dexamethasone suppression test together with BIPSS during their diagnosis workup. A diagnosis of CD was established in 21 patients, confirmed after neurosurgery, with a pathology report of ACTH+ secreting pituitary adenoma, and a biochemical resolution of CS. The additional 4 cases showed an adrenal source of CS. Suppression of 50% or more in the afternoon (of day 1 after 7 mg-dexa IV infusion by 7h starting at 7:00 hrs at 1 mg/hr) was considered consistent with CD. A central-to-peripheral plasma ACTH gradient of ≥2 before and after desmopressin stimulation was also considered consistent with CD during the BIPSS. We calculated kappa index to evaluate concordance between diagnostic test. Also, sensitivity (S), specificity (E), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+) and negative likelihood ratio (LR-) were calculated. Results: The mean age was 43±12.1 years, with a BMI of 30±5.6 kg/m2, 86% females. For the basal ACTH values during BIPSS, the S=76%, E=75%, PPV=94%, NPV=37%, LR+=3, LR-=0.3. For the post-stimulation BIPSS, the S=95%, E=75%, PPV=95%, NPV=75%, LR+=3, LR-=0.06. Using the 7mg-dexa, a S=91%, E=75%, PPV=95%, NPV=60%, LR+=3.6, LR-=0.12. Kappa between test was 0.6 before stimulation, and 0.7 after desmopressin stimulation showing acceptable concordance. Conclusion: The 7 mg-dexa showed similar and acceptable diagnostic performance in comparison with basal or stimulated BIPSS. Since 7mg-dexa inhibition test is less invasive and less expensive, further clinical research to evaluate its utility in CD diagnostic approach is in order. Presentation: Saturday, June 17, 2023

SAT320 Cyclic Cushing Syndrome Caused By An ACTH-Producing Pheochromocytoma

Abstract Disclosure: Y.B. Omotosho: None. M.E. Wierman: None. K. Bukhari: None. K. Pacak: None. R. McGlotten: None. L.K. Nieman: None. Background: Although pheochromocytomas (Pheo) predominantly produce catecholamines, they also rarely produce Adrenocorticotropin (ACTH) and present with Cushing syndrome (CS). Cyclic CS is an uncommon presentation of hypercortisolism. We here report a unique case of cyclic ectopic ACTH secretion from a Pheo. Clinical case: A 72-year-old female was referred to the NIH with a five-year history of intermittent episodes of unintentional weight gain, hair loss, skin thinning, striae, tremors, labile emotions, glucose intolerance, and a sense of impending doom, interspersed with anorexia, weight loss, normal glucose levels, headaches, and fatigue. The external evaluation documented ACTH-dependent CS with episodes of hypercortisolism, thought to be occult ectopic ACTH secretion. On admission, blood pressure ranged from 122/75 to 171/78 mmHg, and she had a Cushingoid habitus. The biochemical investigation showed basal ACTH 219 pg/ml (NL 5- 46 pg/ml); serum cortisol of 76.9 mcg/dl after 1mg dexamethasone (Dex) suppression test (NL &amp;lt;1.8 mcg/dl), with Dex level of 903; cortisol increased from 13.3 mcg/dl to 15.5 mcg/dl after 8mg Dex, Dex level 4680 ng/ml; plasma normetanephrine 1.8 nmol/L, (NL &amp;lt; 0.9 nmol/L); metanephrine 0.6 nmol/L (NL &amp;lt;0.5 nmol/L); norepinephrine 1493 pg/mL (NL 70-750 pg/mL); epinephrine 298 pg/mL (NL &amp;lt;111 pg/mL); chromogranin A 1314 ng/mL (NL &amp;lt;93 ng/mL). MRI pituitary was normal and bilateral inferior petrosal sinus sampling did not show a central: peripheral gradient before or after desmopressin administration. CT abdomen showed a right adrenal nodule measuring 2.3 cm x 1.8 cm, with pre-and post-contrast Hounsfield units of 30 and 106, and 54% washout. The adrenal mass showed intense activity on 68Ga-DOTATATE and 18F-DOPA PET/CT scans. The patient underwent a right adrenalectomy; the 2.7 x 2.3 x 1.5 cm mass was a Pheo with immunohistochemical staining for ACTH, chromogranin A, and synaptophysin. Post-operatively, blood pressure normalized, and medications were reduced from preoperative metoprolol, lisinopril, and doxazosin to low-dose metoprolol at discharge. Morning cortisol and ACTH levels were &amp;lt;1 mcg/dl and &amp;lt;5 pg/ml. Physiologic replacement of hydrocortisone (15 mg on awakening and 5 mg in the afternoon) was started and switched to prednisone 5mg daily for ACTH deficiency and convenience. The pituitary-adrenal axis remained suppressed at her 6-month follow-up visit. Conclusion: Cyclic CS poses a diagnostic challenge. Here, desmopressin helped to exclude Cushing's Disease. Although ACTH-producing Pheo is rare, it should be considered in the context of ACTH-dependent hypercortisolism if an adrenal mass is present. Presentation: Saturday, June 17, 2023

Dexamethasone suppression for 18F-FDG PET/CT to localize ACTH-secreting pituitary tumors

Background18Fluorine-Fluoro-deoxy-glucose (18F-FDG) positron emission tomography (PET) is widely used for diagnosing various malignant tumors and evaluating metabolic activities. Although the usefulness of 18F-FDG PET has been reported in several endocrine diseases, studies on pituitary disease are extremely limited. To evaluate whether dexamethasone (DEX) suppression can improve 18F-FDG PET for the localization of adrenocorticotropic hormone-secreting adenomas in the pituitary gland in Cushing’s disease (CD).MethodsWe included 22 patients with CD who underwent PET imaging before and after DEX administration. We compared the success rates of PET before and after DEX suppression, magnetic resonance imaging (MRI), and bilateral inferior petrosal sinus sampling (BIPSS). We determined the final locations of adenomas based on intraoperative multiple-staged resection and tumor tissue identification using frozen sections. Standardized uptake value (SUV) were analyzed to confirm the change of intensity of adenomas on PET.ResultsTwenty-two patients were included (age at diagnosis: 37 [13–56] years), and most were women (90.91%). Pituitary adenomas compared to normal pituitaries showed increased maximum SUV after DEX suppression but without statistical significance (1.13 versus. 1.21, z=-0.765, P = 0.444). After DEX suppression, the mean and maximum SUV of adenomas showed a positive correlation with nadir cortisol levels in high-dose DEX suppression test (Rho = 0.554, P = 0.007 and Rho = 0.503, P = 0.017, respectively). In reference sites, mean SUV of cerebellum was significantly decreased (7.65 vs. 6.40, P = 0.006*), but those of the thalamus and gray matter was increased after DEX suppression (thalamus, 8.70 vs. 11.20, P = 0.010*; gray matter, 6.25 vs. 7.95, P = 0.010*).ConclusionDEX suppression did not improve 18F-FDG PET/CT localization in patients with CD.

Enhancing Cushing's disease diagnosis: exploring the impact of desmopressin on ACTH gradient during BIPSS.

The differential diagnosis between Cushing's disease (CD) and ectopic ACTH syndrome (EAS) is complex, and bilateral inferior petrosal sinus sampling (BIPSS) is considered the gold-standard test. However, BIPSS with corticotropin-releasing hormone (CRH) stimulation is rarely available. This retrospective cohort study aimed to assess the accuracy of the inferior petrosal sinus to peripheral ACTH gradient (IPS:P) before and after desmopressin stimulation for the differential diagnosis of ACTH-dependent Cushing's syndrome (CS), applying different cutoff values. A total of 50 patients (48 with CD and 2 with EAS) who underwent BIPSS were included in this study. The sensitivity and specificity of IPS:P in BIPSS before and after desmopressin stimulation were evaluated. Various cutoff values for IPS:P were examined to determine their diagnostic accuracy. Using the traditional IPS:P cutoff, the sensitivity was 85.1% before stimulation, 89.6% after stimulation, and a combined sensitivity of 91.7%. Applying cutoff values of IPS:P >1.4 before and >2.8 after stimulation, the sensitivity was 87.2% and 89.6%, respectively, with a combined sensitivity of 91.7%. Receiver operating characteristic (ROC) curve analysis determined optimal cutoff values of 1.2 before stimulation and 1.57 after stimulation, resulting in a sensitivity of 93.6% and 93.8%, respectively, with a combined sensitivity of 97.9%. Specificity remained at 100% throughout all analyses. Among the 43 patients who responded positively to stimulation, 42 (97.7%) did so within the first three minutes, and all 43 (100%) did so within the first five minutes. None of the assessed clinical variables predicted the ACTH response to stimulation in BIPSS with statistical significance. ACTH stimulation with desmopressin during BIPSS improves the accuracy of IPS:P, making it a valuable tool for investigating ACTH-dependent Cushing's syndrome. Considering the low risk of complications, we recommend the use of desmopressin stimulation during BIPSS for the differential diagnosis of ACTH-dependent CS.

Emerging diagnostic methods and imaging modalities in cushing's syndrome.

Endogenous Cushing's syndrome (CS) is a rare disease characterized by prolonged glucocorticoid excess. Timely diagnosis is critical to allow prompt treatment and limit long-term disease morbidity and risk for mortality. Traditional biochemical diagnostic modalities each have limitations and sensitivities and specificities that vary significantly with diagnostic cutoff values. Biochemical evaluation is particularly complex in patients whose hypercortisolemia fluctuates daily, often requiring repetition of tests to confirm or exclude disease, and when delineating CS from physiologic, nonneoplastic states of hypercortisolism. Lastly, traditional pituitary MRI may be negative in up to 60% of patients with adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (termed "Cushing's disease" [CD]) whereas false positive pituitary MRI findings may exist in patients with ectopic ACTH secretion. Thus, differentiating CD from ectopic ACTH secretion may necessitate dynamic testing or even invasive procedures such as bilateral inferior petrosal sinus sampling. Newer methods may relieve some of the diagnostic uncertainty in CS, providing a more definitive diagnosis prior to subjecting patients to additional imaging or invasive procedures. For example, a novel method of cortisol measurement in patients with CS is scalp hair analysis, a non-invasive method yielding cortisol and cortisone values representing long-term glucocorticoid exposure of the past months. Hair cortisol and cortisone have both shown to differentiate between CS patients and controls with a high sensitivity and specificity. Moreover, advances in imaging techniques may enhance detection of ACTH-secreting pituitary adenomas. While conventional pituitary MRI may fail to identify microadenomas in patients with CD, high-resolution 3T-MRI with 3D-spoiled gradient-echo sequence has thinner sections and superior soft-tissue contrast that can detect adenomas as small as 2 mm. Similarly, functional imaging may improve the identification of ACTH-secreting adenomas noninvasively; Gallium-68-tagged corticotropin-releasing hormone (CRH) combined with PET-CT can be used to detect CRH receptors, which are upregulated on corticotroph adenomas. This technique can delineate functionality of adenomas in patients with CD from patients with ectopic ACTH secretion and false positive pituitary lesions on MRI. Here, we review emerging methods and imaging modalities for the diagnosis of CS, discussing their diagnostic accuracy, strengths and limitations, and applicability to clinical practice.

[Exploration of clinical pathway-oriented optimal management diagnosis and treatment model for rare diseases].

This study takes Cushing's syndrome, a rare disease, as a model, and adopts the path of "Plan, Do, Check, Action" (PDCA) to explore new methods to optimize the clinical path, can improve the quality and efficiency of diagnosis and treatment of rare diseases. After sorting out the problems existing in the previous diagnosis and treatment mode, our team optimizes the path in various ways and establishes a standard operation procedure (SOP) for the new path. In the evaluation of the optimized mode, 55 patients with Cushing's syndrome were admitted to the Department of Endocrinology, Peking Union Medical College Hospital, including 19 males and 36 females, aged (41.8±14.4) years (6-68 years). The pathway group (28 cases) and the control group (27 cases) were divided according to whether they were included in the new path management at the time of admission, and the effect of path optimization was assessed in terms of time, efficacy, safety and cost. The results showed that compared with the control group, the pathway group had a shorter time of hospitalization in the Department of Endocrinology and critical tests, such as blood cortisol rhythm, low-dose dexamethasone inhibition test, and bilateral inferior petrosal sinus sampling (all P<0.05). There was no significant differences in the decrease of total cortisol after operation, the incidence of postoperative complications, and hospitalization expenses (all P>0.05). The optimized path improves the medical efficiency while ensuring medical quality, safety and no increase in cost. This study proposes PDCA path optimization for complex diseases and establishes SOP process, which provides experience in management optimization for the patient-centered and clinical path-oriented diagnosis and treatment mode of rare diseases.

Bilateral inferior petrosal sinus sampling: Procedural data from a German single-center study.

To assess radiation exposure and diagnostic performance of bilateral inferior petrosal sinus sampling for the distinction of pituitary and ectopic adrenocorticotropin-dependent Cushing's syndrome. Procedural data of bilateral inferior petrosal sinus procedures were retrospectively evaluated. The analysis included the patients' clinical and demographic data, procedural radiation exposure, and complication rates, sampling results, clinical course of the patients, and calculation of diagnostic performance data. The cases of 46 patients diagnosed with adrenocorticotropin-dependent Cushing's syndrome were evaluated. Bilateral inferior petrosal sinus sampling was successfully performed in 97.8 % of the cases. The overall median procedure-related fluoroscopy time was 7.8 min. (range 3.2-36.2 min.), and the median procedural dose area product was 11.9 Gy*cm2 (range 2.1-73.7 Gy*cm2). Radiation doses due to digital subtraction angiography series for visualization of the inferior petrosal sinus were 3.6 Gy*cm2 (range 1.0-18.1 Gy*cm2). Radiation doses due to fluoroscopy had a higher impact on the overall radiation exposure and were significantly influenced by the patients' habitus. The sensitivity, specificity, and positive and negative predictive values were 84 %, 100 %, 100 %, and 72 % before stimulation with corticotropin-releasing hormone, and 97 %, 100 %, 100 %, and 93 % after stimulation. Concordance between magnetic resonance imaging studies and bilateral inferior petrosal sinus sampling results was only found in 35.6 % of the cases. The periprocedural complication rate was 2.2 %, with one patient experiencing vasovagal syncope during catheterization. Bilateral inferior petrosal sinus sampling is a safe procedure with high technical success rates und excellent diagnostic performance. The procedure-related radiation exposure shows large variations and depends on the complexity of cannulation as well as the patients' habitus. Fluoroscopy accounted for the largest proportion of radiation exposure. Acquisition of digital subtraction angiography series for the verification of correct catheter placement appears justified. · Bilateral inferior petrosal sinus sampling with CRH stimulation provides high diagnostic performance in the distinction of pituitary and ectopic Cushing's syndrome.. · The associated radiation exposure is not negligible and is significantly influenced by the use of fluoroscopy and the patients' habitus.. · Digital subtraction angiography contributes less to the overall radiation dose and appears justified for the verification of correct catheter placement.. · Augustin A, Detomas M, Hartung V et al. Bilateral inferior petrosal sinus sampling: Procedural data from a German single-center study. Fortschr Röntgenstr 2023; 195: 1009 - 1017.

Bilateral inferior petrosal sinus sampling with human CRH stimulation in ACTH-dependent Cushing's syndrome: results from a retrospective multicenter study.

Bilateral inferior petrosal sinus sampling (BIPSS) is regarded as gold standard to differentiate between Cushing´s disease (CD) and ectopic Cushing's syndrome (ECS). However, published data e.g. on the diagnostic value of additional prolactin analysis is controversial. Thus, we evaluated the diagnostic performance of BIPSS with and without prolactin in a multicenter study. Retrospective study in 5 European reference centers. Patients with overt adrenocorticotropin (ACTH)-dependent Cushing's syndrome at the time of BIPSS with human corticotropin-releasing hormone stimulation were eligible. Cut-offs for the inferior petrosal sinus (IPS) to peripheral (P) ACTH ratio and the normalized ACTH:prolactin IPS:P ratio were calculated via receiver operator characteristics analyses (reference: CD). 156 patients with BIPSS were identified. Of these, 120 patients (92 (77%) females; 106 (88%) CD, 14 (12%) ECS) had either histopathologically confirmed tumors or biochemical remission and/or adrenal insufficiency after surgery; only this subgroup was analyzed by ROC analysis. The optimal cut-offs for the ACTH IPS:P ratio were ≥1.9 at baseline (sensitivity 82.1% (95%CI 73.2-88.6), specificity 85.7% (95%CI 56.2-97.5), AUC 0.86) and ≥2.1 at 5 minutes post-CRH (sensitivity 91.3% (95%CI 83.6-95.7), specificity 92.9%(95%CI 64.1-99.6), AUC 0.96). A subgroup underwent additional prolactin analysis. An optimal cut-off of ≥1.4 was calculated for the normalized ACTH:prolactin IPS:P ratio (sensitivity 96.0% (95%CI 77.7-99.9), specificity 100% (95%CI 56.1-100), AUC 0.99). Our study confirms the high accuracy of BIPSS in the differential diagnosis of ACTH-dependent Cushing's syndrome and suggests that the simultaneous measurement of prolactin might further improve the diagnostic performance of this test.

Bilateral Inferior Petrosal Sinus Sampling and Utility of Maximum Stimulated Petrosal Sinus ACTH to Baseline ACTH ratio in Adrenocorticotropin-dependent Cushing's Syndrome

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Should We Use Prolactin Adjustment in Bilateral Inferior Petrosal Sinus Sampling to Diagnose Cushing Disease? A Joint Meta-Analysis of Head-to-Head Diagnostic Tests Accuracy Studies

ObjectivePrevious studies have shown inconsistent results regarding the usefulness of prolactin adjustment in bilateral inferior petrosal sinus sampling (BIPSS) in the differential diagnosis of adrenocorticotropic hormone (ACTH)-dependent Cushing syndrome (CS). This meta-analysis compared the diagnostic accuracy of prolactin adjustment versus no adjustment in BIPSS. MethodsThis study searched the PubMed, Embase, Web of Science, Cochrane library, and WanFang databases for published data as of March 2022 on the use of prolactin adjustment in BIPSS to differentially diagnose ACTH-dependent CS. A Bayesian joint bivariate model was used in the head-to-head comparison of the diagnostic accuracy. ResultsThis meta-analysis included a total of 10 studies with 300 patients. The combined sensitivity and specificity for BIPSS without prolactin adjustment were 94.47% (95% CI, 88.67%-98.44%) and 91.14% (95% CI, 57.17%-99.80%), respectively. The combined sensitivity and specificity after prolactin adjustment were 99.97% (95% CI, 99.03%-100.00%) and 80.69% (95% CI, 50.27%-97.82%), respectively. After the prolactin adjustment, the sensitivity of BIPSS to diagnose Cushing disease was improved with a statistically significant difference (difference in sensitivity, 5.39%; 95% CI, 1.37%-11.26%), whereas the decrease in specificity was without a statistically significant difference (difference in specificity, −9.20%; 95% CI, −42.02% to 26.61%). ConclusionThis meta-analysis indicated that prolactin adjustment in BIPSS might help to recognize Cushing disease among patient with ACTH-dependent CS. However, prolactin adjustment may not help identify ectopic ACTH syndrome in BIPSS.

Comparison of the preoperative diagnostic accuracy of BIPSS versus MRI for Cushing disease: a single-centre experience

BackgroundCushing disease (CD) arises due to a pituitary corticotroph adenoma, which is the most common cause of Cushing syndrome (CS). Bilateral inferior petrosal sinus sampling (BIPSS) is a safe method for differentiating CD from ectopic adrenocorticotropic hormone (ACTH)-dependent CS. Enhanced high-resolution magnetic resonance imaging (MRI) can localize tiny pituitary lesions. The aim of this study was to compare the preoperative diagnostic accuracy of BIPSS versus MRI for CD in CS patients. We performed a retrospective study of patients who underwent BIPSS and MRI between 2017 and 2021. Low- and high-dose dexamethasone suppression tests were performed. Blood samples were collected simultaneously from the right and left catheter and femoral vein before and after desmopressin stimulation. MRI images were obtained, and endoscopic endonasal transsphenoidal surgery (EETS) was performed in confirmed CD patients. Dominant sides of ACTH secretion during BIPSS and MRI were compared with surgical findings.ResultsTwenty-nine patients underwent BIPSS and MRI. CD was diagnosed in 28 patients, 27 of whom received EETS. Localizations of microadenomas by MRI and BIPSS agreed with the EETS findings in 96% and 93% of the cases, respectively. BIPSS and EETS were successfully performed on all patients.ConclusionBIPSS was the most accurate method (gold standard) for establishing a preoperative diagnosis of pituitary-dependent CD and was more sensitive than MRI in diagnosing microadenoma. High-resolution MRI with enhancement had an advantage over BIPSS in microadenoma lateralization diagnostics. The combined use of MRI and BIPSS could improve the preoperative diagnosis accuracy in ACTH-dependent CS patients.

Ectopic sphenoidal ACTH-secreting adenoma revealed by 11C Methionine PET scan: case report

BackgroundEctopic ACTH pituitary adenomas (EAPA), located outside the sella turcica and deriving from cellular remnants of Rathke’s pouch are a very rare cause of Cushing’s syndrome (CS). The diagnosis is often difficult and delayed, even after comprehensive work-up. To our knowledge, we report for the first time an ectopic corticotroph tumor of the posterior wall of the sphenoid sinus, leading to false positive results of bilateral inferior petrosal sinus sampling (BIPPS) and which was finally localized by a co-registered11 C Methionine PET/MR imaging.Case presentationA 48-year-old woman was referred for a high clinical suspicion of ACTH-dependent CS. Biological testing comprising low dose dexamethasone suppression and CRH stimulation tests were indicative of pituitary Cushing’s disease, but comprehensive pituitary MRI did not reveal any pituitary adenoma. BIPSS confirmed however a central origin of ACTH secretion (central-to-peripheral ACTH ratio > 100) and revealed a significant right-to-left gradient (6.2), leading to a first right-sided exploratory hypophysectomy, that did not cure the patient. BIPSS images were reviewed and revealed preferential drainage of the left pituitary to the right petrosal sinus, leading us to a left sided exploratory hypophysectomy, which was again unsuccessful. A11 C Methionine PET/MRI was performed and revealed a hypermetabolic lesion adjacent to the posterior wall of the sphenoidal sinus. After surgical resection, this polypoid mass was identified as an ectopic ATCH-secreting pituitary adenoma expressing ACTH and T-Pit and complete remission of hypercortisolism was observed.ConclusionsIn conclusion, we report a case of ACTH-dependent Cushing’s syndrome, caused by an ectopic corticotroph adenoma located in the sphenoidal sinus, which perfectly mimicked the biological features of a classical pituitary ACTH adenoma on a comprehensive hormonal evaluation including BIPPS, and the features of a benign naso-sinusal polyp at MRI. We report for the first time a key role of11 C Methionine PET co-registered to high resolution MRI for localizing ectopic adenomas, efficiently guiding surgical removal and leading to complete remission of hypercortisolism.

PMON152 In Patients with Cushing's Disease and a Visible Tumor on MRI, IPSS does not Add to the Accuracy of Predicting Tumor Lateralization

Abstract Introduction There is controversy surrounding the value of bilateral inferior petrosal sinus sampling (BIPSS) for tumor lateralization in Cushing's disease (CD). We compare lateralization results between BIPSS and pituitary imaging against gold-standard surgical localization. Methods A retrospective chart review was conducted in patients with pathology-confirmed CD, visible tumor on MRI (with and without contrast), and who underwent BIPSS at our institution between 2003-2020. An inferior petrosal sinus to peripheral (IPS/P) prolactin ratio &amp;gt;1.8 was used to confirm appropriate IPS sampling. An inter-sinus ACTH gradient ratio greater than 1.4, adjusted for prolactin where available, was used to determine lateralization. In each case, the neurosurgeon performed a full pituitary gland exploration to avoid missing any tumors despite visible tumor on MRI. Descriptive statistics were used. Results Of 32 patients with CD, visible tumor on MRI, and BIPSS testing, 27 (84%) patients had technically successful bilateral IPSS catheterization and are the subjects of this study. All 27 of these patients had IPS/P ACTH ratio greater than 2 at baseline or 3 after CRH stimulation, consistent with CD, and all 27 lateralized. The median age at diagnosis was 42 years (range 21-69 years) and 85% were female (N=23). The median tumor size on MRI was 5 mm (range 3-8 mm). In 22/27 (81%) patients, the result of the IPSS lateralization was concordant with MRI findings. When MRI and BIPSS lateralization agreed, 21/22 (95%) were confirmed by surgical pathology. Of the 5 cases where MRI and BIPSS disagreed on laterality, the operative report was consistent with MRI lateralization in 3/5 cases, and bilateral disease in the remaining 2 cases. There were no cases where BIPSS lateralization was correct when MRI lateralization was incorrect. Overall, MRI correctly lateralized 26/27 cases (96%), whereas BIPSS correctly lateralized 23/27 (85%). In the subset of 13 patients with tumors measuring &amp;lt;6mm on MRI, MRI imaging lateralization was correct in all 13 (100%) cases and BIPSS lateralization was correct in 11/13 (85%). Adverse events associated with BIPSS were noted in 4 patients (15%) ranging from hematoma to headache. Among the 5 patients who did not have successful BIPSS cannulization, one experienced the adverse effect of transient severe headache. There were no serious complications. The surgeons performed bilateral sellar exploration in all cases regardless of BIPSS or MRI lateralization results. Conclusion When a tumor is visible on MRI, regardless of its size (≥ 3mm), BIPSS does not add to the accuracy of determining tumor lateralization. BIPSS may best be reserved for situations where the diagnosis of CD is in question. Further studies are required to determine the value of BIPSS in lateralizing the source of CD in patients without visible tumor. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

ODP340 NOVEL THERAPY OSILODROSTAT AS AN OPTION FOR RECURRENT CUSHING'S DISEASE

Abstract Introduction Cushing's Disease (CD) denotes a pathologic endogenous hypercortisolism secondary to excessive adrenocorticotropic hormone (ACTH) production. Cushing Disease is a rare condition with an estimated incidence of approximately 1.2-1.4 new cases / 1. 000. 000 per year. Although surgical intervention is the gold standard in the management of CD, many patients may present persistence or recurrence of disease despite surgical intervention, resulting in significant deterioration of their quality of life (QoL). For those in whom pituitary surgery is not an option or has not been curative, medical therapies have been developed. One of these newer treatments is the drug Osilodrostat, an inhibitor of the enzyme 11-beta-hydroxylase, responsible for the final step of cortisol biosynthesis in the adrenal glands. Case Discussion Case of a 21 year-old female patient with history of Cushing's Disease status post-transsphenoidal surgery (TSS) in 2017, obesity and oligomenorrhea who presented to our clinics showing signs and symptoms of hypercortisolism despite previously documented post-surgical remission in 2017. Patient reported recent development of acne, weight gain, round face, elevated blood pressure and mood changes. At the moment of evaluation, her most recent MRI showed post-surgical changes without a discrete lesion. Work-up was compatible with recurrence of Cushing's with an ACTH at 75pg/mL (nl, 10-60pg/mL), urinary free cortisol (UFC) at 1,122mcg/24h (nl, 4-50mcg/24h) and serum morning cortisol at 24. 0mcg/dL (nl, 5-20mcg/dL). In view of a negative MRI for a pituitary lesion, a Bilateral Inferior Petrosal Sinus Sampling (BIPSS) was performed. The BIPSS procedure revealed a pituitary source with a right pituitary lateralization suggestive of a right ACTH-producing tumor. The patient was consulted to Neurosurgery Service, but while waiting for repeat surgery, control of hypercortisolism was needed. The patient was started on Osilodrostat 2mg twice a day and was able to achieve normalization of UFC to 4mcg/24h, serum morning cortisol 5mcg/dL and late-night salivary cortisol (LNSC) of 30ng/dl (&amp;lt;90ng/dL) with significant improvement in her QoL, depression and clinical manifestations. The patient tolerated therapy well. Conclusion Cushing's Disease is a complex condition with potential serious complications if untreated. Even though TSS is the first line therapy, approximately 25% of patients show persistence of disease, and a similar proportion may experience recurrence. When surgery fails, medical treatment such as Osilodrostat, can temporarily suppress excessive cortisol production and ameliorate its clinical manifestations improving patients’ QoL while more definitive therapy is established. Presentation: No date and time listed