PET/CT detects more distant metastases than conventional staging in patients with NPC. The largest benefit in terms of cost and patient management was observed in the subgroup with N2-3 disease and EBV DNA ≥ 4,000 copies/mL.

Objective To explore the feasibility of targeted imaging of the angiotensin II subtype 1 receptor (AT1R) in cardiac tissue, using clinical hybrid positron emission tomography/computed tomography (PET/CT). Background AT1R is an attractive imaging target due to its key role in various cardiac pathologies, including post-infarct left ventricular remodeling. Methods Using the novel AT1R ligand [11C]-KR31173, dynamic PET/CT was performed in young farm pigs under healthy conditions (n=4), and 3–4 weeks after experimental myocardial infarction (n=5). Ex vivo validation was carried out by immunohistochemistry and PCR. First-in-man application was performed in 4 healthy volunteers, at baseline and under AT1R blocking. Results In healthy pigs, myocardial KR31173 retention was detectable, regionally homogeneous, and specific for AT1R, as confirmed by blocking experiments. Metabolism in plasma was low (85±2% of intact tracer after 60min). After myocardial infarction, KR31173 retention, corrected for regional perfusion, revealed AT1R upregulation in the infarct area relative to remote myocardium, while retention was elevated in both regions when compared to myocardium of healthy controls (8.7±0.8 and 7.1±0.3 vs 5.8±0.4 %/min for infarct and remote vs healthy controls; p<0.01 each). Postmortem analysis confirmed AT1R upregulation in remote and infarct tissue. First-in-man application was safe, and showed detectable and specific myocardial KR31173 retention, at an albeit lower level than pigs (LV average retention: 1.2±0.1 vs 4.4±1.2%/min for humans vs pigs; p=0.04). Conclusion Noninvasive imaging of cardiac AT1R expression is feasible using clinical PET/CT technology. Results provide a rationale for broader clinical testing of AT1R-targeted molecular imaging.

No abstract

No abstract