Prospect of positron emission tomography for abdominal aortic aneurysm risk stratification

Abstract

Abdominal aortic aneurysm (AAA) disease is characterized by an asymptomatic, permanent, focal dilatation of the abdominal aorta progressing towards rupture, which confers significant mortality. Patient management and surgical decisions rely on aortic diameter measurements via abdominal ultrasound surveillance. However, AAA rupture can occur at small diameters or may never occur at large diameters, implying that anatomical size is not necessarily a sufficient indicator. Molecular imaging may help identify high-risk patients through AAA evaluation independent of aneurysm size, and there is the question of the potential role of positron emission tomography (PET) and emerging role of novel radiotracers for AAA. Therefore, this review summarizes PET studies conducted in the last 10 years and discusses the usefulness of PET radiotracers for AAA risk stratification. The most frequently reported radiotracer was [18F]fluorodeoxyglucose, indicating inflammatory activity and reflecting the biomechanical properties of AAA. Emerging radiotracers include [18F]-labeled sodium fluoride, a calcification marker, [64Cu]DOTA-ECL1i, an indicator of chemokine receptor type 2 expression, and [18F]fluorothymidine, a marker of cell proliferation. For novel radiotracers, preliminary trials in patients are warranted before their widespread clinical implementation. AAA rupture risk is challenging to evaluate; therefore, clinicians may benefit from PET-based risk assessment to guide patient management and surgical decisions.

The role and mechanism of epidermal growth factor receptor in hemodynamic induction of abdominal aortic aneurysm formation

“…However, the accuracy of predicting the risk of AAA rupture based on AAA diameter is controversial, as monitoring of vessel diameter shows that even an AAA diameter <55 mm is likely to rupture. Studies have confirmed that women with AAA have a higher risk of rupture than men, and smokers and those with untreated hypertension are also at increased risk ( 25 - 27 ). It is still a hot research topic to assess the specific rupture risk of patients with AAA by monitoring aneurysm volume, aortic size index (ratio of body surface area to aneurysm diameter), family history of AAA, diabetes mellitus, and biomarkers.…”

Risk prediction for abdominal aortic aneurysm: One size does not necessarily fit all

“…As a result, the majority of studies performed in humans have used F 18 -FDG, despite its known lack of disease-specific activity and variable efficacy results. 2 Importantly, the authors suggest some of these difficulties could be mitigated by ''repurposing'' agents that have already been evaluated in cancer patients. Notable agents undergoing preliminary clinical testing in patients with AAA that have been used to image the aforementioned biological processes in cancer include the calcification marker F 18 -NaF 18 and the inflammatory chemokine receptor Cu 64 -DOTA-ECL1i (NIH-CCR2 AAA study), 19 which have been previously evaluated in preclinical models and ex vivo human AAA tissue.…”

[18F]Fluorothymidine Uptake in the Porcine Pancreatic Elastase-Induced Model of Abdominal Aortic Aneurysm

“…However, anatomical size alone may be insufficient as an indicator of prognosis. Positron emission tomography (PET)/computed tomography (CT) is posited to be useful for patient risk stratification and represents an active field of study in the context of AAA [ 1 , 2 , 3 ].…”