[Show abstract][Hide abstract] ABSTRACT: Our objective was to evaluate the association of arterial (18)F-FDG uptake and calcifications in large arteries as detected by (18)F-FDG PET/CT with the subsequent occurrence of vascular events in otherwise asymptomatic cancer patients.
Clinical follow-up information was obtained for 932 cancer patients examined with whole-body (18)F-FDG PET/CT (median follow-up time, 29 mo). Among this cohort, 279 patients had died from their oncologic disease. In 15 of 932 patients (1.6%), a vascular event, defined as ischemic stroke, myocardial infarction, or revascularization, was registered. The maximal standardized uptake value (SUV) was divided by the blood-pool SUV, yielding a target-to-background ratio (TBR) for each arterial segment. The mean TBR as well as a calcified plaque sum score per patient were calculated in the major vessels: ascending, descending, and abdominal aorta, aortic arch, as well as iliac and carotid arteries.
A significant correlation was observed between mean TBR and calcified plaque sum (P < 0.001). Although calcified plaque sum significantly correlated with all conventional risk factors for vascular events, mean TBR correlated only with age, the male sex, and hypertension. The Cox regression hazard model identified a mean TBR >or= 1.7 and a calcified plaque sum >or= 15 as independent predictors for the occurrence of a vascular event. Patients with both mean TBR and calcified plaque sum above these thresholds were identified as having the highest risk for a future vascular event. However, a mean TBR >or= 1.7 had greater prognostic value than did a calcified plaque sum >or= 15.
In a large cohort of cancer patients, increased (18)F-FDG uptake in major arteries emerged as the strongest predictor of a subsequent vascular event. Concomitant severe vascular calcifications seemed to impart a particularly high risk. Given the small event rate in the present study, larger, prospective trials of patients without cancer are required to substantiate these promising results.
Full-text · Article · Sep 2009 · Journal of Nuclear Medicine
[Show abstract][Hide abstract] ABSTRACT: To evaluate the incremental prognostic value of coronary artery calcification (CAC) scoring over single photon emission computed tomographic (SPECT) myocardial perfusion imaging in long-term prognosis and survival of patients with stable coronary artery disease (CAD).
All patients provided written informed consent to undergo CAC scoring according to a protocol that was approved by the local clinical institutional review board. Over a median follow-up time of 5.4 years, 260 patients with stable CAD were followed up for severe cardiac events (cardiac death or nonfatal myocardial infarction). CAC scanning and SPECT myocardial perfusion imaging were performed at enrollment. Patients were stratified on the basis of well-established cutoff points for CAC score, summed stress score (SSS), and summed rest score (SRS). Kaplan-Meier survival curves and the Cox proportional hazards model were used.
CAC score and SRS were identified as the only independent predictors of event-free survival. Patients with perfusion abnormalities at rest (SRS > or = 2), a CAC score greater than 400, or severe perfusion abnormalities under stress (SSS > or = 13) were identified as having significantly increased risk for subsequent severe cardiac events (P = .023, .0095, and .007, respectively). In addition, a CAC score greater than 400 offered incremental prognostic value over the scintigraphic scores alone (P = .028 with an SSS > 8; P = .008 with an SRS > or = 2).
CAC score and SRS were identified as independent predictors of severe cardiac events during long-term follow-up of patients with known CAD. CAC scores imparted superior risk stratification information as compared with SPECT myocardial perfusion imaging results alone.