Endocrine Abstracts

Background: 11C-Metomidate (MTO)-PET/CT has recently found utility as an alternative to adrenal vein sampling for lateralisation in primary aldosteronism. MTO binds with high affinity to 11b-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) and can be considered an adrenocortical-specific tracer. We and others have therefore hypothesised that combining MTO-PET/CT with 18F-FDG(FDG)-PET/CT would permit indeterminate adrenal lesions ...

Introduction: Primary aldosteronism (PA) is a common and potentially reversible cause of secondary hypertension, characterised by resistance to standard antihypertensive therapy and possible hypokalaemia. Lateralisation investigations, including adrenal vein sampling (AVS), are required to distinguish between unilateral or bilateral disease, with unilateral disease representing a potentially surgically curable form of PA. The majority of patients proceeding to adrenalectomy re...

Background: Prolactinomas are the commonest hormone-secreting pituitary adenomas. First-line treatment is dopamine agonist (DA) therapy. However, side-effects are increasingly recognised, leading to an increasing consideration of transsphenoidal surgery (TSS) and/or radiotherapy. Co-registration of 11C-methionine Positron Emission Tomography (Met-PET) imaging with Spoiled Gradient Recalled Acquisition MRI (SPGR MRI), referred to in combination as Met-PET/MRI, can aid accurate ...

Background: Primary aldosteronism (PA) is an important, potentially curable, cause of hypertension. Distinguishing unilateral and bilateral causes is a critical step in determining who should be considered for adrenalectomy. Adrenal vein sampling (AVS) remains the gold standard for lateralisation. However, AVS is technically challenging with limited availability. To address this, we have introduced molecular imaging using PET/CT with the radiotracer [11C]Metomidate ...

Background: In a sub-group of patients with newly diagnosed pituitary adenomas, conventional MRI will fail to confidently localise the tumour. The role of molecular imaging for these patients is increasingly being recognised, both in terms of confirming diagnosis and in guiding targeted therapy; 11C-Methionine PET co-registered with volumetric MRI (Met-PET/MRCR) can enhance decision making in this group of patients. However, in some cases distinguishing t...

Section 1: Case history: A 69 year old man with chronic obstructive pulmonary disease was admitted with acute onset shortness of breath. A CT pulmonary angiogram revealed no focal lung abnormality but identified an incidental 40 x 32 mm left-sided adrenal lesion. An unenhanced CT, undertaken to characterise the lesion, showed a homogeneous, well-circumscribed appearance with a radiodensity of 4 Hounsfield units. Prior to involvement of the Endocrinology team, a dedicated MRI w...

Objective: To determine if an extended lateral approach to trans-sphenoidal surgery (TSS), guided by 11C-Methionine PET/CT co-registered with volumetric MRI (Met-PET/MRCR), can lead to remission in patients with persistent acromegaly due to post-operative lateral/para-sellar tumour remnants.Methods: We identified eight patients with persistent acromegaly following primary intervention [TSS ± medical therapy ± radiotherapy ...

Background: Primary aldosteronism (PA) is the leading, potentially reversible, cause of secondary hypertension. For most patients in whom surgery is being considered, adrenal vein sampling (AVS) is recommended to distinguish unilateral and bilateral causes. However, AVS remains technically challenging, and a significant proportion of patients are unable to progress to surgery because AVS is unavailable or unsuccessful. We have explored whether [11C]Metomidate PET/CT...