Responsiveness of FDG PET/CT to treatment of patients with active chronic sarcoidosis.

PURPOSE: This study aimed to compare baseline to follow-up 18F-FDG PET/CT findings after treatment for active chronic sarcoidosis and to correlate changes on 18F-FDG PET/CT with changes in clinical status. PATIENTS AND METHODS: The sample included 66 patients with chronic sarcoidosis and evidence of active inflammation on baseline F-FDG PET/CT for which they received therapy. Of these 66 patients, 30 returned for the follow-up 18F-FDG PET/CT after 12 (5) months to evaluate response to treatment. They were also asked to indicate changes in clinical status. Baseline characteristics of patients who did and did not return for the follow-up were compared to assess selection bias. RESULTS: SUVmax was significantly decreased at the follow-up compared with baseline 18F-FDG PET/CT (8.46 [3.52] vs 4.90 [0.96]; P = 0.006), primarily in the mediastinum. Inflammatory activity appeared absent in 9 patients, decreased in 12 patients, and increased in 9 patients, with the corresponding changes in SUVmax of -80%, -41%, and +54%, respectively. The changes on 18F-FDG PET/CT were in agreement with self-perceived changes in clinical symptoms (P = 0.019). The angiotensin-converting enzyme at the follow-up was not significantly different from baseline (49.80 [19.25] vs 46.35 [25.58], P = 0.522). There was no difference in baseline characteristics of patients who did and did not return for the follow-up. CONCLUSIONS: 18F-FDG PET/CT is able to detect clinically meaningful changes in magnitude and extent of inflammatory activity in patients receiving treatment for active chronic sarcoidosis. Thus, 18F-FDG PET/CT is a valuable adjunct to clinical evaluation for monitoring the response to treatment in these patients.

The utility of 18F-FDG PET/CT for diagnosis and adjustment of therapy in patients with active chronic sarcoidosis.

UNLABELLED: The purpose of this study was to assess the utility of (18)F-FDG PET/CT for detection of inflammation in granulomatous sites and management of patients with chronic sarcoidosis. The 3 specific aims were to assess differences between (18)F-FDG PET/CT and multidetector CT (MDCT) findings, to compare (18)F-FDG PET/CT results with serum levels of angiotensin-converting enzyme (ACE), and to determine whether (18)F-FDG PET/CT findings are associated with the decision to change therapy. METHODS: We studied 90 sarcoidosis patients (mean age ± SD, 47 ± 12 y; 32 men and 58 women) with persistent symptoms who were referred for (18)F-FDG PET/CT evaluation to assess the extent of inflammation. They also underwent MDCT and measurement of serum ACE level. After the follow-up (12 ± 5 mo after (18)F-FDG PET/CT), the clinical status and changes in therapy were analyzed. RESULTS: (18)F-FDG PET/CT detected inflammation in 74 patients (82%) (maximum standardized uptake value, 8.1 ± 3.9). MDCT was positive for sarcoidosis in 6 additional patients (80, 89%). The difference between the 2 methods was not significant (P = 0.238, McNemar test), and their agreement was fair (κ = 0.198). Although ACE levels were significantly higher in patients with positive than negative (18)F-FDG PET/CT results (P = 0.002, Mann-Whitney test), 38 patients (51%) with positive (18)F-FDG PET/CT results had normal ACE levels. The therapy was initiated or changed in 73 out of 90 patients (81%). Both univariate and multivariate logistic regression analyses indicated that positive (18)F-FDG PET/CT results were significantly (P < 0.001) associated with changes in therapy, with no contribution from age, sex, ACE level, CT results, or previous therapy. CONCLUSION: Our results indicate that (18)F-FDG PET/CT is a useful adjunct to other diagnostic methods for detecting active inflammatory sites in chronic sarcoidosis patients with persistent symptoms, especially those with normal ACE levels. (18)F-FDG PET/CT proved advantageous for determining the spread of active disease throughout the body and influenced the decision to adjust the therapy.

The utility of two somatostatin analog radiopharmaceuticals in assessment of radiologically indeterminate pulmonary lesions.

PURPOSE: The aim of our study was to assess diagnostic accuracy of Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC scintigraphy for evaluation of pulmonary lesions that appeared ambiguous on computed tomography (CT). MATERIAL AND METHODS: Forty-nine consecutive patients (37 men and 12 women; mean age, 60 ± 11 years) with 60 pulmonary lesions on chest radiography and CT were referred for nuclear imaging. They were prospectively allocated to undergo whole-body scintigraphy (WBS) and single photon emission computed tomography (SPECT) using either Tc-99m depreotide (26 patients, group 1) or Tc-99m-EDDA/HYNIC-TOC imaging (23 patients, group 2). Histologic findings after tissue biopsy served as a gold standard for determining diagnostic accuracy of the 2 somatostatin analogs. Visual assessment was complemented by semiquantitative analysis based on target to background ratio. RESULTS: Among the 32 pulmonary lesions scanned with Tc-99m depreotide, focal uptake was increased in 22 of 25 malignancies, whereas no uptake was found in 6 of 7 benign lesions (88% sensitivity, 85% specificity, and 88% accuracy) on both WBS and SPECT. Imaging of 28 pulmonary lesions with Tc-99m-EDDA/HYNIC-TOC had a similar diagnostic yield (sensitivity 87%, specificity 84%, and accuracy 86%). Overall, target to background ratios were higher on SPECT than WBS but not significantly different between groups 1 and 2 (SPECT 2.72 ± 0.70 vs. 2.71 ± 0.50, WBS 1.61 ± 0.32 vs. 1.62 ± 0.28, respectively). CONCLUSION: This study demonstrates that Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC have similar diagnostic value for characterizing pulmonary lesions that appear ambiguous on CT.

Usefulness of gated SPECT myocardial imaging in evaluation of patients with inferior myocardial infarction.

OBJECTIVE: Gated single photon emission computed tomography (gated SPECT) myocardial imaging gives useful information about the extent and severity of perfusion abnormalities (PA) and global left ventricular (LV) function in patients with coronary artery disease. The aim of this study was to evaluate by gated SPECT myocardial imaging differences in perfusion scores and LV function between stress and rest in patients with mild left ventricular dysfunction and/or normal function and previous inferior myocardial infarction (IMI) and to detect myocardial stunning. MATERIALS AND METHODS: The study included 77 patients (age 53 ± 8.21) with mild left ventricular dysfunction and previous IMI divided into two groups. Group 1 consisted of 34 patients with IMI and additional ischemia on perfusion scan and group 2 with 43 patients with previous IMI without ischemia on perfusion scan. All patients underwent a 2-day stress-rest gated SPECT myocardial imaging protocol with 99m technetium-methoxyisobutylisonitrile ((99m)Tc-MIBI). RESULTS: There was a more significant post-stress to rest decrease in ejection fraction (EFps) in patients with IMI and additional ischemia (group 1) than in patients with IMI (group 2) (-1.5 ± 2.5 vs. 1.5 ± 2.3, p < 0.001). In group 1, there was a significant increase in post-stress end-systolic volume (ESVps) in comparison to ESVr (70.4 ± 29.8 vs. 66.2 ± 26.2 ml, p = 0.044). However, the decrease in EF post-stress to rest did not reach the level of significance (51.7 ± 10.8 vs. 53.2 ± 10.2%, p = 0.147). The extent and severity of perfusion abnormalities were higher on stress (SSS) than on rest images (SRS) (13.9 ± 8.6 vs. 8.3 ± 7.8, p < 0.001). There was no difference in global LV parameters or perfusion abnormalities in patients in group 2 between stress and rest except for a significant increase in the post-stress EF to rest value (57.9 ± 11.9 vs. 56.2 ± 10.5%, p = 0.018). Severe decrease of post-stress EF to rest was found in 12 (16%) patients indicating stunning. CONCLUSION: In patients with mild left ventricular dysfunction and IMI with additional ischemia there is evidence of a decrease in the post-stress EF with an increase in the post-stress ESV. In addition, a significant association between the decrease of post-stress EF with the extent and severity of perfusion abnormalities was detected. Gated SPECT myocardial imaging has an important role in the evaluation of perfusion and LV function in patients with IMI especially in patients with additional ischemia.

Metabolic syndrome impacts the right ventricle: true or false?

BACKGROUND: The impact of metabolic syndrome (MS) on the right ventricle (RV) is not clarified. The aim of this study was to evaluate the influence of MS and its components on RV structure and function. METHODS: The study included 265 subjects with MS and 118 controls adjusted by age. MS was defined by the presence of ≥3 ATP-NCEP III criteria. All subjects underwent laboratory blood tests, complete two-dimensional, pulse, and tissue Doppler echocardiography. We determined the ratio of early and late diastolic tricuspid flow velocities (E/A)(t), and the ratio of early diastolic transtricuspid and septal tricuspid annuli flow velocity (E/e')(t). RV Tei index represents the sum of tricuspid isovolumic relaxation time (IVRT) and tricuspid isovolumic contraction time (IVCT) divided by RV ejection time (ET) [(IVRT + IVCT)/ET]. RESULTS: Multiple regression analysis showed that systolic blood pressure (ß = 0.104, P = 0.021), waist circumference (ß = 0.093, P = 0.033), glucose level (ß = 0.087, P = 0.045), left ventricular mass (LVmass) index (ß = 0.218, P < 0.001) and relative LV wall thickness (ß = 0.144, P = 0.034) were independently associated with the RV hypertrophy. Multivariate analysis showed that waist circumference (ß = 0.152, P = 0.013), glucose level (ß = 0.119, P = 0.039), LVmass index (ß = 0.267, P < 0.001), the relative LV wall thickness (ß = 0.184, P = 0.005), RV wall thickness (ß = 0.175, P = 0.008), and (E/e')m (ß = 0.143, P = 0.025) were independently associated with (E/e')(t). Similar results were obtained for RV Tei index. CONCLUSIONS: MS has an important role in damage of RV structure and function. Among MS criteria systolic blood pressure, waist circumference and glucose level were independently associated with RV structure and function.

Preliminary experience with 18f-fluoro-deoxy-glucose positron emission tomography/computed tomography in pediatric oncology patients.

The aim of this study was to present preliminary experience with FDG PET/CT in pediatric oncology patients in National PET Center, Clinical Center of Serbia and to asses its impact on management of malignancies in children. 33 FDG PET/CT scans were performed on 30 pediatric patients. PET/CT imaging was performed for staging the disease, assessing therapy efficacy and diagnosing recurrent or metastatic disease. FDG PET/CT changed the stage of the disease in 60.6% (20/33) of the cases. 14 patients were down-staged after PET/CT, mostly patients with Hodgkin's disease, were in 7/10 cases PET/CT showed no activity in residual masses. Six scans led to upstage of the disease. In three cases PET/CT did not change the stage of disease, but has showed new distant metastases. In conclusion, FDG PET/CT showed important role in managing pediatric patients with different malignancies and was useful complementary diagnostic tool to conventional imaging methods.