Pituitary magnetic resonance imaging vs. bilateral inferior petrosal sinus sampling: comparison between non-invasive and invasive diagnostic techniques for Cushing's disease-a narrative review

Non-Invasive Biochemical Testing of ACTH-dependent Cushing's Disease: Do We Still Need Petrosal Sinus Sampling?

Differentiating between a pituitary from an ectopic source of ACTH could be a real one of the major challenges of clinical endocrinology. The Bilateral inferior petrosal sinus sampling (BIPSS) is considered the gold standard for identifying the source of ACTH; however, is not available worldwide. After the SARS-CoV-2 pandemic, algorithms that include biochemical and imaging tests have gained importance as an alternative to BIPSS. This review summarizes the drawbacks in the differential diagnosis of ACTH-dependent Cushing; the evolution of diagnostic tests, and the evidence that exists on their performance. As well as a comparison between the advantages and disadvantages of invasive and non-invasive tests.

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

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

KEY POINTS

· 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..

CITATION FORMAT

· 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.

Long-Term Outcomes and Complications from Endoscopic Versus Microscopic Transsphenoidal Surgery for Cushing's Disease: A 15-Year Single-Center Study

BACKGROUND

Endoscopic endonasal surgery is the main transsphenoidal approach for pituitary surgery in many centers; however, few studies compare the endoscopic and microscopic surgical approaches with regard to long-term follow-up. This single-center study aimed to compare the 2 techniques over 15 years.

METHODS

Medical records and magnetic resonance images from 40 patients with primary transsphenoidal surgery for Cushing's disease at Sahlgrenska University Hospital between 2003 and 2018 were reviewed. 14 patients who underwent microscopic surgery and 26 patients who underwent endoscopic surgery were included in this study.

RESULTS

In the microscopic group, 12 of 14 patients achieved endocrine remission, compared to 19 of 26 patients in the endoscopic group (n. s.). Three patients in each group developed a late recurrence. Complications were seen in 5 patients in the microscopic group and in 8 patients in the endoscopic group (n. s.). No serious complications, such as carotid artery damage, cerebrovascular fluid leakage, epistaxis, or meningitis, occurred in any group. The postoperative hospital stay was shorter in the endoscopic than in the microscopic group.

CONCLUSIONS

Endoscopic endonasal surgery for Cushing's disease showed no difference in remission, recurrence, and complication rates compared to the microscopic approach. The endoscopic group had a shorter postoperative hospital stay than the microscopic group, which in part may be due to the minimal invasiveness of the endoscopic approach.

Evolution in endoscopic endonasal approach for the management of hypothalamic–pituitary region metastasis: A single-institution experience

Introduction

Endonasal endoscopic surgery has changed the treatment perspectives for different lesions of the hypothalamic–pituitary region. The metastases of the hypothalamic–pituitary region represent 0.4% of all intracranial metastatic tumors and account for only 1.8% of surgically managed pituitary lesions. The aim of tshis study is to describe a single-center institutional experience with 13 cases of hypothalamic–pituitary metastasis focused on presurgical workup, the evolution of the surgical technique, and postsurgical management according to our protocols, showing effects on progression-free and overall survival rates for this relatively uncommon location.

Material and Methods

We retrospectively reviewed the whole series of patients that received the endoscopic endonasal approach at the Division of Neurosurgery at the University of Naples “Federico II” undergoing surgery from January 1997 to December 2021. We identified 13 cases whose pathology reports revealed a metastatic lesion. Statistical analysis was performed to determine the Kaplan–Meier survival function and assess for log-rank differences in survival based on gender, surgical treatment, and postoperative therapy (p-value < 0.02*).

Results

The pathology report disclosed lung adenocarcinoma (six cases, 46%), breast adenocarcinoma (two cases, 15.4%), clear cell renal carcinoma (one case, 7%), melanoma (one case, 7%), colorectal adenocarcinoma (one case, 7%), uterine cervix carcinoma (one case, 7%), and follicular thyroid carcinoma (one case, 7%). A standard endoscopic endonasal approach was performed in 10 patients (76.9%), while an extended endonasal procedure was performed in only three cases (23%). Biopsy was the surgical choice in five patients with infiltrative and invasive lesions and a poor performance status (38%), while in the cases where neurovascular decompression was necessary, a subtotal resection was achieved in five patients (38%) and partial resection in three patients (23%). Recovery of visual field defect was observed in six of seven patients with visual loss (85.7%), improvement of oculomotor nerve palsy occurred in four of seven patients with this defect (57.1%), while the impairment of oculomotor palsy was observed in three patients (42.9%). Visual function was stable in the other patients. The median progression-free survival and overall survival were 14 and 18 months, respectively. There were statistically significant differences in PFS and OS in patients who underwent adjuvant radiotherapy (p=0.019 is referred to OS and p=0.017 to PFS, respectively; p-value = 0.02).

Conclusions

The endoscopic endonasal approach is a viable approach for the management of hypothalamic–pituitary metastases as this surgery provides an adequate opportunity to obtain tissue sample and neurovascular decompression, both being crucial for continuing the integrated adjuvant therapy protocols.

Endocrinological aspects of pituitary adenoma surgery in Europe

Hormone-secreting adenomas are treated in many neurosurgical centers within Europe. The goal of the survey is to understand variance in practice management of pituitary tumors amongst neurosurgical centers. A list of departments performing pituitary surgery was created. The survey consisted of 58 questions. This study focuses on neurosurgical care of hormone-secreting adenomas. For analysis, the departments were divided into four subgroups: academic/non-academic, high-volume/low-volume, “mainly endoscopic/mainly microscopic practice” and geographical regions. Data from 254 departments from 34 countries were obtained. Most centers surgically treat 1–5 hormone-secreting adenomas per year. In prolactinomas this is the case in 194 centers, (76.4%), in GH-secreting adenomas: 133 centers, (52.4%), ACTH-secreting adenomas: 172 centers, (69.8%). Surgery as a primary treatment of prolactinomas is considered in 64 centers (25.2%). In 47 centers (18.8%), GH-secreting microadenomas are often treated pharmacologically first. Debulking surgery for an invasive GH-secreting adenoma in which hormonal remission is not a realistic goal of the surgery and the patient has no visual deficit surgery is always or mostly indicated in 156 centers (62.9%). Routine postoperative hydrocortisone replacement therapy is administered in 147 centers (58.6%). Our survey shows that in most centers, few hormone-secreting adenomas are treated per year. In about 25% of the centers, prolactinoma surgery may be regarded as first-line treatment; in about 20% of the centers, medical treatment is the first-line treatment for GH-secreting adenomas. Pretreatment for ACTH-secreting adenomas is routinely used in 21% of centers. This survey may serve as plea for neurosurgical care centralization of hormone-secreting adenomas.

Contrast-enhanced 3D-T2-weighted SPACE sequence for MRI detection and localization of adrenocorticotropin (ACTH)-secreting pituitary microadenomas

OBJECTIVE

Cushing disease is a potentially fatal endocrine disorder caused by adrenocorticotropin (ACTH)-secreting microadenomas in the pituitary gland. Accurate detection and localization of the adenomas is the key to clinical treatment. This study analysed the value of contrast-enhanced Sampling Perfection with Application-optimized Contrasts using different flip angle Evolutions (SPACE) sequence in magnetic resonance imaging (MRI) assessment of ACTH-secreting pituitary microadenomas.

DESIGN AND PATIENTS

We carried out a retrospective study in which 45 patients with ACTH-secreting pituitary microadenomas were enrolled. Dynamic contrast-enhanced (DCE) coronal T1-SE sequence was performed. A contrast-enhanced coronal SPACE sequence was added immediately after DCE MRI finished. Two independent observers assessed the tumour existence and location, then the results were compared with surgical findings.

RESULTS

Twenty-four lesions (53.3%) were detected by the DCE T1-SE sequence alone, while 35 lesions (80.0%) were detected with the addition of contrast-enhanced SPACE sequence. The sensitivity (58.5% vs. 85.3%; p < .05) and best diagnostic accuracy (62.0% vs. 84.4%; p < .05) were significantly better for addition with SPACE sequence than DCE-SE images alone in detection of ACTH-secreting pituitary microadenomas. For lesions <5 mm, the detected numbers were 4 (16.6%) versus 10 (27.8%) by DCE T1-SE sequence and combined DCE T1-SE with SPACE sequence.

CONCLUSIONS

A combination of contrast-enhanced SPACE with DCE T1-SE sequence could improve the detection of ACTH-secreting pituitary microadenomas. Contrast-enhanced SPACE sequence could be a supplementary sequence for imaging of ACTH-secreting pituitary adenomas when T1-SE sequence provides negative or equivocal findings.

The role of bilateral inferior petrosal sinus sampling in determining the preoperative localization of ACTH-secreting pituitary microadenomas in Cushing's disease: Experience of a tertiary center

INTRODUCTION

Bilateral inferior petrosal sinus sampling (BIPSS) is an important procedure in the diagnostic work-up of Cushing's syndrome (CS). In this study, we investigated the diagnostic performance of BIPSS in detecting the source of adrenocorticotropic hormone (ACTH) secretion in Cushing's disease (CD) without radiological evidence.

METHODS

Thirty-five consecutive patients who underwent BIPSS due to ACTH-dependent CS between 2010 and 2019 in our clinic and subsequently underwent transsphenoidal surgery were included. The indication for BIPSS was biochemically proven ACTH-dependent CS but normal or ≤6 mm pituitary lesion in pituitary magnetic resonance imaging (MRI). Corticotropin releasing hormone (CRH) stimulation was applied to all patients during the BIPSS procedure. BIPSS data, MRI results, pathological findings, and follow-up results were analyzed. The diagnostic performance of BIPSS was calculated.

RESULTS

A total of 35 patients, 6 (17%) males and 29 (83%) females, were included in the study. Pituitary MRI was normal in 12 (34.3%) and revealed lesions ≤ 6 mm in 23 (65.7%) patients. BIPSS lateralized the right side in 13 (37.1%) and left side in 18 (51.4%) patients, while no lateralization was observed in the remaining 4 (11.5%) patients. BIPSS showed lateralization in the same direction with pituitary adenoma in 21 (60%) patients before CRH injection and in 29 (83%) patients after CRH injection (p = 0.034). The sensitivity of the BIPSS procedure was 88%. Accurate localization of the pituitary lesion was more frequent when based on BIPSS results than on MRI (83% vs. 51%, P = 0.005).

CONCLUSION

BIPSS appears to be a valuable and safe diagnostic tool in patients who are diagnosed with CD biochemically but do not have clear radiological evidence of ACTH-producing lesion.

New types of localization methods for adrenocorticotropic hormone-dependent Cushing's syndrome

The management of endogenous Cushing's syndrome (CS) typically involves two key steps: (i) confirmation of autonomous hypercortisolism and (ii) localization of the cause to guide treatment. Adrenocorticotropic hormone (ACTH)-dependent CS is most commonly due to a pituitary corticotrope tumor which may be so small as to evade detection on conventional magnetic resonance imaging (MRI). Although biochemical testing (e.g., corticotropin stimulation; dexamethasone suppression) can provide an indication of the likely origin of ACTH excess, bilateral inferior petrosal sinus catheterization offers greater accuracy to distinguish pituitary-driven CS [Cushing's Disease (CD)] from the ectopic ACTH syndrome [EAS, e.g., due to a bronchial or pancreatic neuroendocrine tumor (NET)]. In patients with CD, 40-50% may not have a pituitary adenoma (PA) readily visualized on standard clinical MRI. In these subjects, alternative MR sequences (e.g., dynamic, volumetric, fluid attenuation inversion recovery) and higher magnetic field strength (7T > 3T > 1.5T) may aid tumor localization but carry a risk of identifying coincidental (non-causative) pituitary lesions. Molecular imaging is therefore increasingly being deployed to detect small ACTH-secreting PA, with hybrid imaging [e.g., positron emission tomography (PET) combined with MRI] allowing precise anatomical localization of sites of radiotracer (e.g., ¹¹C-methionine) uptake. Similarly, small ACTH-secreting NETs, missed on initial cross-sectional imaging, may be detected using PET tracers targeting abnormal glucose metabolism (e.g., ¹⁸F-fluorodeoxyglucose), somatostatin receptor (SSTR) expression (e.g., ⁶⁸Ga-DOTATATE), amine precursor (e.g., ¹⁸F-DOPA) or amino acid (e.g., ¹¹C-methionine) uptake. Therefore, modern management of ACTH-dependent CS should ideally be undertaken in specialist centers which have an array of cross-sectional and functional imaging techniques at their disposal.