Detection and global quantification of cardiovascular molecular calcification by fluoro18-fluoride positron emission tomography/computed tomography--a novel concept.

The aim of this study was to examine the degree and prevalence of regional (aorta) and global (cardiac) fluorine-18-sodium fluoride ((18)F-NaF) uptake by positron emission tomography (PET)-computed tomography (CT) as evidence for calcification in the atherosclerotic plaques in the aorta and the heart as a function of age. Image data from 51 patients, who had undergone whole-body (18)F-NaF-PET/CT, were evaluated retrospectively. Cardiac and arterial (aorta) radiotracer uptakes were analyzed quantitatively by measuring standard uptake values (SUV). This approach involved examining the entire heart and various aortic segments as identified by CT. By combining CT and PET data, regional and global concentrations of this molecule were calculated and correlated with age over the decades. (18)F-NaF uptake in the heart and aorta increased significantly with advancing age (P<0.01). The Pearson correlation coefficient for the mean (18)F-NaF uptake of cardiac region and 5 age groups was 0.92 (P=0.003) and for aorta and 5 age groups was 0.97 (P=0.004). In conclusion, these preliminary data indicate the feasibility of (18)F-NaF-PET/CT for measurement of regional and global calcification of the heart and major arteries. The (18)F-NaF-PET/CT may provide highly relevant information about the state of calcified plaque before structural calcification is detectable by standard CT techniques. This, therefore, may allow for earlier intervention for risk reduction in cardiovascular diseases. Further studies are needed to validate the role of this promising technique in the management of patients with suspected atherosclerosis.

Role of Pepsin and Oropharyngeal pH-Monitoring to Assess the Postoperative Outcome of Patients with Laryngopharyngeal Reflux: Results of a Pilot Trial.

BACKGROUND: The aim of this study was to evaluate the value of salivary pepsin and oropharyngeal pH-monitoring to assess the surgical outcome of patients with laryngopharyngeal reflux (LPR). MATERIALS AND METHODS: Twenty consecutive patients with LPR despite proton pump inhibitor treatment received laparoscopic antireflux surgery. Twenty-four hour esophageal pH-monitoring (multichannel intraluminal impedance monitoring [MII]-pH) and esophageal manometry (high-resolution manometry) data were documented preoperatively and at 3-month follow-up. An ears, nose and throat (ENT) examination was performed, including assessment of Belafsky Reflux Finding Score (RFS). Clinical symptoms were evaluated with the Belafsky Reflux Symptom Index (RSI) and the Gastrointestinal Quality of Life Index (GIQLI). Simultaneous to the MII-pH and collection of saliva samples, detection of oropharyngeal reflux events was performed. Treatment failure was defined as postoperative pathologic RFS or RSI score and improvement of GIQLI of <10 points, despite showing a normal DeMeester score. RESULTS: At baseline, all patients had a pathological ENT examination, RSI score, and MII-pH data. All patients showed postoperatively a normal DeMeester score (mean 6.39 ± 4.87). Five patients were defined as treatment failures with a change of pepsin concentration from median 157.0 (95% confidence interval [CI]: 0-422) to 180.7 (95% CI: 0-500). In patients defined as treatment success, median pepsin value decreased from 206.3 (95% CI: 89-278) to 76.0 (95% CI: 55-205); (P = .093). Oropharyngeal pH-monitoring data showed no significant change in both groups. CONCLUSION: Salivary pepsin could be a marker for treatment success, while oropharyngeal pH-monitoring seems to be inadequate in these terms. However, larger studies are required to reach firm conclusions.

18F-NaF-PET/CT and 99mTc-MDP Bone Scintigraphy in the Detection of Bone Metastases in Prostate Cancer.

99mTc-MDP whole-body bone scintigraphy is a highly sensitive imaging method that has been used for decades to evaluate prostate cancer bone metastasis based on its availability and low cost; however, because of accumulation of this radiotracer in degenerative, traumatic, and inflammatory lesions, it suffers from noncomparable specificity. The modality is also used to monitor response to therapy and to predict patients' prognosis. As planar imaging may not give enough information for lesion detection or anatomical localization, it can be supplemented with SPECT to increase image contrast particularly in the evaluation of small and complex skeleton. In addition, hybrid SPECT/CT can be used to assess both functional and morphologic changes leading to more accurate detection of the metastatic bone lesions in a single-section test. 18F-NaF-PET/CT offers excellent advantages in investigating bone metastases. It provides greater spatial resolution and better image quality, resulting in better sensitivity and specificity. Furthermore, 18F-NaF-PET/CT is able to evaluate response to therapy more accurately and to detect occult bone metastases in lower prostate-specific antigen levels when comparing with conventional 99mTc-labeled whole-body bone scan. Owing to smaller administered dose and shorter half-life of 18F-NaF, the total actual radiation absorbed dose is almost comparable with 99mTc-labeled conventional bone scintigraphy. Hence, we believe that conventional bone scintigraphy would be replaced by 18F-NaF-PET/CT in the assessment of metastatic bone disease where PET/CT scanners are available.

Evaluation of Prostate Cancer Bone Metastases with 18F-NaF and 18F-Fluorocholine PET/CT.

18F-fluorocholine is a specific promising agent for imaging tumor cell proliferation, particularly in prostate cancer, using PET/CT. It is a beneficial tool in the early detection of marrow-based metastases because it excludes distant metastases and evaluates the response to hormone therapy. In addition, 18F-fluorocholine has the potential to differentiate between degenerative and malignant osseous abnormalities because degenerative changes are not choline-avid; however, the agent may accumulate in recent traumatic bony lesions. On the other hand, 18F-NaF PET/CT can indicate increased bone turnover and is generally used in the assessment of primary and secondary osseous malignancies, the evaluation of response to treatment, and the clarification of abnormalities on other imaging modalities or clinical data. 18F-NaF PET/CT is a highly sensitive method in the evaluation of bone metastases from prostate cancer, but it has problematic specificity, mainly because of tracer accumulation in degenerative and inflammatory bone diseases. In summary, 18F-NaF PET/CT is a highly sensitive method, but 18F-fluorocholine PET/CT can detect early bone marrow metastases and provide greater specificity in the detection of bone metastases in patients with prostate cancer. However, the difference seems not to be significant.