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Purpose: To investigate the potential role of serum thyroglobulin doubling time (TgDT) in predicting 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) PET/CT results in patients affected by differentiated thyroid carcinoma (DTC) who demonstrated a combination of positive Tg but a negative [131I] whole-body scan ([131I]-WBS). Materials and methods: Inclusion criteria were (1) prior [131I] treatment for DTC, (2) negative subsequent [131I]-WBS, (3) no interfering anti-Tg antibodies, (4) three consecutive Tg measurements under the thyroid hormone replacement therapy to calculate TgDT before 2-[18F]FDG PET/CT, and (5) at least 6 months of clinical and/or imaging follow-up to ascertain the diagnosis. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to identify the optimal cutoff point for the last stimulated Tg and TgDT prior to [18F]FDG PET/CT. Results: One hundred and thirteen patients were included. Seventy-four (65%) patients had positive [18F]FDG PET/CT for DTC recurrence, while the remaining 39 (35%) negative. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of [18F]FDG PET/CT were 92%, 94%, 97%, 87%, and 93%. Patients with positive [18F]FDG PET/CT had higher Tg and TgDT than those with negative PET/CT. ROC curve analysis revealed an optimal Tg cutoff of 19 ng/mL (sensitivity 78%, specificity 85%, AUC = 0.844) and TgDT of 2.5 years (sensitivity 93%, specificity 87%, AUC = 0.911). TgDT threshold of 2.5 years predicted significantly (p = 0.023) better than Tg level PET/CT results. Conclusions: The diagnostic performance of [18F]FDG PET/CT could be significantly improved when TgDT is less than or equal to 2.5 years, as compared with using the absolute Tg level. [ABSTRACT FROM AUTHOR]

Purpose: Burkitt’s lymphoma (BL) is an aggressive lymphoma subtype with high 18F-FDG avidity at 18F-FDG-PET/CT, but no validated criteria for PET/CT in treatment evaluation or prediction of outcome in BL are available. The aim of our study was to investigate whether the metabolic baseline PET/CT parameters can predict treatment response and prognosis in BL.Materials and methods: We retrospectively enrolled 65 patients who underwent baseline 18F-FDG-PET/CT, interim and end of treatment PET/CT. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value body weight (SUVbw), the maximum standardized uptake value lean body mass (SUVlbm), the maximum standardized uptake value body surface area (SUVbsa), lesion to liver SUVmax ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), total metabolic tumor volume (tMTV) and total lesion glycolysis (TLG). Survival curves were plotted according to the Kaplan-Meier method.Results: At a median follow-up of 40 months, the median PFS and OS were 34 and 39 months. MTV and TLG were significantly higher in patients with partial response compared to complete response group at end of treatment, while no significant differences were found at interim. Other metabolic PET/CT parameters were not related to treatment response. MTV and TLG were demonstrated to be independent prognostic factors for both PFS and OS; instead SUVbw, SUVlbm, SUVbsa, L-L SUV R and L-BP SUV R were not related to outcome survival.Conclusions: Metabolic tumour features (MTV and TLG) were significantly correlated with response to treatment and long-term outcome. [ABSTRACT FROM AUTHOR]

Purpose: Cardiac transthyretin-related amyloidosis (ATTR) is a progressive and fatal cardiomyopathy. The diagnosis of this disease is frequently delayed or missed due to the limited specificity of echocardiography. An increasing amount of data in the literature demonstrate the ability of bone scintigraphy with bone-seeking radiopharmaceuticals to detect myocardial amyloid deposits, in particular in patients with ATTR. Therefore we performed a systematic review and bivariate meta-analysis of the diagnostic accuracy of bone scintigraphy in patients with suspected cardiac ATTR.Methods: A comprehensive computer literature search of studies published up to 30 November 2017 on the role of bone scintigraphy in patients with ATTR was performed using the following search algorithm: (a) “amyloid” OR “amyloidosis” AND (b) “TTR” OR “ATTR” OR “transthyretin” AND (c) “scintigraphy” OR “scan” OR “SPECT” OR “SPET” OR “bone” OR “skeletal” OR “skeleton” OR “PYP” OR “DPD” OR “HMDP” OR “MDP” OR “HDP”. Pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR−) and diagnostic odds ratio (DOR) of bone scintigraphy were calculated.Results: The meta-analysis of six selected studies on bone scintigraphy in cardiac ATTR including 529 patients provided the following results: sensitivity 92.2% (95% CI 89-95%), specificity 95.4% (95% CI 77-99%), LR+ 7.02 (95% CI 3.42-14.4), LR− 0.09 (95% CI 0.06-0.14), and DOR 81.6 (95% CI 44-153). Mild heterogeneity was found among the selected studies.Conclusion: Our evidence-based data demonstrate that bone scintigraphy using technetium-labelled radiotracers provides very high diagnostic accuracy in the non-invasive assessment of cardiac ATTR. [ABSTRACT FROM AUTHOR]

Purpose: Solitary plasmacytoma (SP) is a rare plasma-cell neoplasm, which can develop both in skeletal and/or soft tissue and frequently progresses to multiple myeloma (MM). Our aim was to study the metabolic behavior of SP and the role of 18F-FDG-PET/CT in predicting progression to MM. Materials and methods: Sixty-two patients with SP who underwent 18F-FDG-PET/CT before any treatment were included. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and compared with age, sex, site of primary disease, and tumor size. Results: Fifty-one patients had positive 18F-FDG-PET/CT (average SUVbw was 8.3 ± 4.7; SUVlbm 5.8 ± 2.6; SUVbsa 2 ± 1; MTV 45.4 ± 37; TLG 227 ± 114); the remaining 11 were not 18F-FDG-avid. Tumor size was significantly higher in patients avid lesions compared to FDG not avid; no other features are associated with FDG-avidity. Progression to MM occurred in 29 patients with an average of 18.3 months; MM was more likely to develop in patients with bone plasmacytoma and in patients with 18F-FDG avid lesion. Time to transformation in MM (TTMM) was significantly shorter in patients with osseous SP, in 18F-FDG avid lesion, for SUVlbm > 5.2 and SUVbsa > 1.7. Conclusions: 18F-FDG pathological uptake in SP occurred in most cases, being independently associated with tumor size. PET/CT seemed to be correlated to a higher risk of transformation in MM, in particular for 18F-FDG avid plasmacytoma and SBP. Among semiquantitative features, SUVlbm > 5.2 and SUVbsa > 1.7 were significantly correlated with TTMM. [ABSTRACT FROM AUTHOR]

Purpose: The role of 18F-FDG-PET/CT in evaluating gastric MALT lymphoma is still controversial. In the literature the detection rate of 18F-FDG-PET/CT in patients with gastric MALT lymphoma is variable, and the reason for this heterogeneity is not still clear. Our aim was to investigate the particular metabolic behavior of these lymphoma. Materials and methods: Sixty-nine patients (26 female, 43 male) with histologically confirmed gastric MALT lymphoma who underwent a 18F-FDG-PET/CT for initial staging from two centers were included. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio and compared with Ann Arbor stage, epidemiological (age, sex), histological (presence of gastritis, ulcer, H. pylori infection, plasmacytic differentiation, Ki-67 index), and morphological (tumor size, superficial lesions or mass-forming) characteristics. Results: Thirty-six patients (52 %) had positive PET/CT (average SUVmax was 9±6.7; lesion-to-liver SUVmax ratio 3.7±2.6, lesion-to-blood pool SUVmax ratio 4.8±3.3) at the corresponding gastric lesion; the remaining 33 were not 18F-FDG-avid. In the univariate analysis, 18F-FDG avidity was significantly associated with morphological features (mass forming p<0.001 and high maximum diameter p<0.001), Ann Arbor stage ( p=0.010), and Ki67 index ( p<0.001) and not correlated with age, sex, presence of gastritis, ulcer, Helicobacter pylori infection, and plasmacytic differentiation. In the multivariate analysis, the correlations with gross morphological appearance, Ann Arbor stage, and Ki-67 score were confirmed. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio correlated significantly only with Ki67 index ( p=0.047; p=0.012; p=0.042). Conclusions: 18F-FDG avidity was noted in 52 % of gastric MALT lymphoma and this avidity is correlated with gross morphological characteristics, tumor stage, and Ki-67 index. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio are correlated only with Ki-67 index, and only lesion-to-liver SUVmax ratio was independently associated with Ki-67 score. [ABSTRACT FROM AUTHOR]

Purpose: Our aim was to investigate the association between F-fluorodeoxyglucose (FDG) uptake and event-free survival in patients in whom a differentiated thyroid cancer (DTC) was detected by F-FDG positron emission tomography (PET)/CT. Methods: Among 884 focal F-FDG PET thyroid incidentalomas referred to our 4 Nuclear Medicine Departments, we investigated 54 patients in whom a DTC was confirmed and a clinical follow-up was available. The ratio between maximum standardized uptake value (SUV) of DTC and SUV of the liver (SUV ratio) was recorded for each scan. All patients underwent total thyroidectomy and I remnant ablation. After a median follow-up of 39 months we assessed the outcome. The association between disease persistence/progression, F-FDG uptake and other risk factors (T, N, M and histological subtype) was evaluated through univariate and multivariate analyses. Results: Of the 54 patients, 39 achieved complete remission. The remaining 15 showed persistence/progression of disease. High F-FDG uptake, i.e. SUV ratio ≥3, showed a low positive predictive value (48 %). Low F-FDG uptake (SUV ratio < 3) displayed a high negative predictive value (93 %). The median of SUV ratios in T1-T2 (2.2), in M0 (2.7) and in non-virulent subtypes (2.7) were significantly lower ( p < 0.03) than in T3-T4 (5.0), M1 (7.3) and virulent subtypes (6.0). Kaplan-Maier analysis showed a significant association between high F-FDG uptake and disease persistence/progression ( p = 0.001). When we adjusted risk estimates by using a multivariate Cox model, only T ( p = 0.05) remained independently associated with disease persistence/progression. Conclusion: An intense F-FDG uptake of the primary DTC is associated with persistence/progression of disease. However, when all other prognostic factors have been taken into account, F-FDG uptake does not add further prognostic information. [ABSTRACT FROM AUTHOR]

For this reason, the current ATA guidelines suggest that [18F]-FDG PET/CT should be performed when stimulated-Tg (s-Tg) levels are > 10 ng/ml [[3]], but other papers have proposed different Tg threshold to predict PET/CT results always with good accuracy [[4]]. Although the positivity rate of [18F]-FDG PET/CT increases as the Tg level rises, true-positive findings have also been reported in 10-20% of DTC patients with Tg levels < 10 ng/ml, suggesting a potential role of PET/CT also in cases of low-moderate positive s-Tg [[6]]. The possible concern of a time delay in performing [18F]-FDG PET/CT and subsequent detection of disease in this group of patients due to the wait of TgDT seem not so significant. [Extracted from the article]

Purpose: In clinical myocardial single photon emission computed tomography (SPECT), attenuation artefacts may cause a loss of specificity in the identification of diseased vessels that can be corrected by means of gated SPECT (GSPECT) acquisition or CT attenuation correction (AC). The purpose of this multicentre study was to assess the impact of GSPECT and AC on the diagnostic performance of myocardial scintigraphy, according to patient's sex, body mass index (BMI) and site of coronary artery disease (CAD). Methods: We studied a group of 104 patients who underwent coronary angiography within 1 month before or after the SPECT study. Patients with a BMI > 27 were considered 'overweight'. Attenuation-corrected and standard GSPECT early images were randomly interpreted by three readers blinded to the clinical data. Results: In the whole group, GSPECT and AC showed a diagnostic accuracy of 86.5% (sensitivity 82%, specificity 93%) and 77% (sensitivity 75.4%, specificity 81.4%), respectively ( p < 0.05). In women, when anterior ischaemia was matched with CAD, AC failed to show any increase in specificity (AC 63.6% vs GSPECT 63.6%) with evident loss of sensitivity (AC 72.7% vs GSPECT 90.9%). AC significantly improved SPECT specificity in the identification of right CAD in overweight men (AC 100% vs GSPECT 66.7%, p <0.05). Conclusion: AC improved specificity in the evaluation of right CAD in overweight men. In the other evaluable subgroups specificity was not significantly affected while sensitivity was frequently reduced. [ABSTRACT FROM AUTHOR]

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6–10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60–70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was the evaluation of septal wall motion, perfusion and wall thickening after CABG in two groups of consecutive patients, one with grafted left anterior coronary artery and no history of myocardial infarction, and the other with previous anteroseptal myocardial infarction and impaired septal motion before surgery The issue addressed was the ability of gated SPHCT to differentiate between true paradoxical septal motion, characterised by paradoxical wall motion, depressed ejection fraction (HF), poor viability and compromised wall thickening, and pseudo- paradoxical motion, characterised by abnormal wall motion and regional HF hut preserved perfusion and wall thickening. Methods: One hundred and thirty-two patients with previous anterior myocardial infarction, 82 patients with left anterior descending coronary disease and no history of myocardial infarction and 27 normal subjects underwent rest gated SPHCT after 99mTc- sestamibi injection, according to the standard QGS protocol Quantitative regional HF, regional perfusion, regional wall motion and regional wall thickening were determined using a 20-segment model Results: Despite the presence of similar regional wall motion impairment in patients with and patients without septal infarction, in terms of regional HF (2.5%±3% vs I .9%±4.9% p=NS) and inward septal motion (3±4.9 mm vs 2.3±6.1 mm p=NS), significant differences were observed in both perfusion (74.7%±6.2% vs 63.3%±13%, p>0.0001) and regional wall thickening (17.2%±7.4% vs 12.6%±7.2%, p>0.0001). Conclusion: Gated SPHCT with perfusion tracers can reliably differentiate pseudo-paradoxical from true paradoxical septal motion in patients with previous CABG, and it may he the method of choice for evaluating left ventricular performance in this patient population. [ABSTRACT FROM AUTHOR]

An introduction to articles discussed within the issue is presented, including heart rate response to regadenoson, and heart rate response to vasolidator stress.

The article comments on the paper "Myocardial Perfusion Reserve in Spared Myocardium: Correlation With Infract Size and Left Ventricular Ejection Fraction" by L. E. Juárez-Orozco et al. The paper found the correlation of both infract size and myocardial perfusion with ejection faction in a group of patients with previous myocardial infarct. It also identified several factors that produce endothelial dysfunction, including hypercholesterolaemia, smoking, diabetes mellitus and hypertension.

A letter to the editor is presented in response to the article "FFDG PET/CT changes therapy management in high-risk DTC after first radioiodine therapy," by S. J. Rosenbaum-Krumme and colleagues in the 2012 issue.

A letter to the editor is presented in response to the article "SPECT imaging evaluation in movement disorders: far beyond visual assessment," by K. Badiavas and colleagues in the 2010 issue.