18F-FDG PET or PET/CT role in plasmacytoma: A systematic review. / Papel de la 18F-FDG PET o PET/TC en el plasmocitoma: una revisión sistemática.

BACKGROUND: The metabolic behavior of plasmacytoma at 18F-FDG PET/CT is not yet clear. OBJECTIVE: The aim of this systematic review was to analyze published data about the role of 18F-FDG PET or PET/CT in patients affected by plasmacytoma. METHODS: Acomprehensive computer literature search of the Scopus, PubMed/MEDLINE, Embase and Cochrane Library databases was conducted including articles up to July 2019 to find relevant published papers about the performance of 18F-FDG PET and PET/CT in plasmacytoma. RESULTS: The comprehensive computer literature search revealed 371 articles. On reviewing the titles and abstracts, 363 articles were excluded because the reported data were not within the field of interest of this review. Eight articles were selected and retrieved in full-text version. From the analyses of the selected studies, the following main findings have been founded: 1) plasmacytoma generally is a 18F-FDG-avid tumor and PET/CT had good diagnostic performance with high sensitivity; 2) 18F-FDG PET/CT influenced patient management in most cases avoiding useless therapies and choosing the best therapeutic approach; 3) prognostic value of PET/CT qualitative and semiquantitative parameters is only suggested with controversial reports. CONCLUSION: Despite several limitations affect this analysis, especially related to the low number of articles and patients studied, plasmacytoma looks to be an 18F-FDG-avid tumor in most of the cases; 18F-FDG PET or PET/CT had good diagnostic performance and had a significant clinical impact in change of therapeutic approach. Moreover, a possible prognostic role of PET/CT features is described.

18F-FDG PET/CT brown fat detection: Differences between adult and pediatric population in a 12 year experience. / Detección de grasa parda en la PET/TC con 18F-FDG: diferencias entre la población adulta y pediátrica en una experiencia de 12 años.

PURPOSE: To analyze epidemiological and anthropometric features of patients with brown adipose tissue (BAT) activation detected by fluorine18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). MATERIAL AND METHODS: From 2005 to 2017, 818 18F-FDG PET/CT studies positive for BAT detection were retrospectively included, 742 examinations performed on the adult population and 76 PET/CT on the pediatric population. A Chi-squared test was performed to compare features distribution between the adult and pediatric patients. RESULTS: Adults showed a higher rate of BAT detection in females (79% vs. 61%, P<0.001) and in hyperglycaemic patients (>100mg/dL) (24% vs. 16%, P=0.02), no significant difference was found with regard to overweight patients (BMI>25kg/m2) (22% vs. 20%, P=.55). Considering females only, the adults showed a higher rate of BAT detection both in hyperglycaemic (83% vs. 42%, P<0.001) and overweight patients (80% vs. 67%, P=0.005). In both populations BAT activation happened more frequently in cold seasons; there was no significant distribution difference with regard to season of birth (P=0.2). CONCLUSIONS: Sex, glycemia and BMI play a major role in predicting BAT activation, with significant differences between adults and pediatric patients. Cold exposure is confirmed as an important predicting factor, while season of birth is not significant.

Role of 18F-FDG PET/CT in restaging and follow-up of patients with uterine sarcomas. / 18F-FDG PET/TC en reestadificación y seguimiento de pacientes con sarcomas uterinos.

PURPOSE: Uterine sarcomas are rare tumors with poor prognosis due to the high recurrence rates. The current role of 18F-FDG PET/CT in the post-therapy surveillance is not established yet. MATERIALS AND METHODS: Forty-one women with uterine sarcoma underwent 73 18F-FDG PET/CT for restaging in suspected recurrence or during follow-up in asymptomatic patients. Histopathology results and/or clinical/imaging follow-up for at least 12 months were considered the reference standard. The diagnostic accuracy and clinical impact of 18F-FDG PET/CT was calculated. RESULTS: Thirty-three 18F-FDG PET/CT were positive, while the remaining 40 studies were negative. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 18F-FDG PET/CT were 88%, 98%, 97%, 91% and 93%, respectively. Considering patients with clinical or radiological suspicion of recurrence (n=47) and those during follow-up (n=26), sensitivity, specificity, PPV, NPV and accuracy of 18F-FDG PET/CT were 89%, 100%, 100%, 86% and 94%, and 80%, 95%, 80%, 95% and 92%, respectively. 18F-FDG PET/CT had a positive clinical impact in 9/73 (12%) studies and changed the clinical management in 8/41 (20%) patients. CONCLUSIONS: 18F-FDG PET/CT seems to be an accurate method for detection and localization of local and distant recurrence in patients with uterine sarcoma with good sensitivity and specificity and significant impact on clinical decision making.

Clinical and prognostic value of 18F-FDG PET/CT in recurrent endometrial carcinoma. / Valor clínico y pronóstico de la PET/TC con 18F-FDG en el cáncer de endometrio recurrente.

PURPOSE: Endometrial carcinoma (EC) is a cancer with a good overall prognosis, except in cases of recurrent or advanced EC. The aim of this study was to assess the diagnostic performance, the prognostic value and the impact on therapeutic management of 18F-FDG PET/CT in suspected recurrent EC. MATERIALS AND METHODS: We retrospectively evaluated 157 patients with histologically proven EC and restaging 18F-FDG PET/CT for suspected recurrence. The PET images were analyzed visually and semi-quantitatively by measuring SUVmax, MTV and TLG. A combination of clinical/imaging follow-up and/or histopathology was taken as reference standard. Progression-free survival (PFS) and overall survival (OS) were computed using Kaplan-Meier curves. RESULTS: Seventy-nine patients had positive 18F-FDG PET/CT showing the presence of at least one hypermetabolic lesion consistent with recurrence, while the remaining 78 were negative. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG PET/CT were 96%, 99%, 99%, 96%, 97%, respectively, and were higher compared to conventional imaging: 97%, 62%, 72%, 96%, 80%. After a mean follow-up of 39months, relapse/progression occurred in 58 patients and death in 37 with an average time of 22.1 and 27.6months, respectively. A positive 18F-FDG PET/CT and advanced FIGO stage were significantly associated with shorter PFS and OS. PET/CT results had a significant impact on therapeutic approach in 33 patients: avoiding unnecessary therapies in 28 and modifying therapy in 5. CONCLUSIONS: 18F-FDG PET/CT has a very good diagnostic performance in patients with suspected recurrent EC and has an important prognostic value in assessing PFS and OS. Moreover, PET/CT allowed for a change in treatment decision in about 20% of cases.

Different uptake of 123I-MIBG in the two main liver lobes: A persistant unsolved mistery. / Diferente captación de 123I-MIBG en los 2 lóbulos hepáticos principales: un misterio persistente sin resolver.

PURPOSE: After radiopharmaceutical injection, a heightened 123I-MIBG concentration is frequently observed in the left hepatic lobe compared to the right one, but the reason of this finding remains unknown. Our aim was to retrospectively analyze the different 123I-MIBG uptake pattern between the two hepatic lobes and correlate our results with some epidemiological/clinical features. MATERIAL AND METHODS: Ninety-four 123I-MIBG scintigraphies from 71 patients were selected. Regions of interest were drawn in the right and left lobes using transverse tomographic sections and left to right activity ratios (L/R ratio) were calculated at 6 and 24h after radiotracer administration. RESULTS: Twenty-seven examinations were positive for hypermetabolic lesions while the remaining 67 were negative. In all cases mean early and delayed L/R ratios were greater than 1.00; average early L/R ratio was 1.37 and delayed L/R ratio 1.52. The delayed L/R ratio was significantly higher than the early one. There was no difference in the L/R ratios with regard to age, gender, primary disease and result of scintigraphy. CONCLUSIONS: 123I-MIBG uptake was higher in left hepatic lobe compared to right and this ratio did not correlate with any epidemiological or clinical feature. The reason of this metabolic is not yet explained and some biomolecular hypotheses could be tested in 3D dynamic in vitro models.

Real-life management and outcome of thyroid carcinoma-related bone metastases: results from a nationwide multicenter experience.

PURPOSE AND PATIENTS: The M.O.S.CA.TI. (Metastases of the Skeleton from CArcinoma of the ThyroId) is a multicenter, retrospective study investigating the real-life outcome and management of bone metastases (BM) in 143 patients (63 M, 80 F; median age 64 years, range 11-87) with differentiated thyroid carcinoma (DTC). RESULTS: Radio-active iodine (RAI) treatment was performed in 131 patients (91.6%), surgical approach and/or external radiotherapy in 68 patients (47.6%), and anti-resorptive bone-active drugs in 32 patients (22.4%; in 31 zoledronate and in one denosumab). At the start of treatment, 24 patients (75.0%) receiving anti-resorptive bone-active drugs had at least one clinical skeletal-related event (SRE) (p < 0.001). One or more clinical SREs (pathological fractures and/or malignant hypercalcemia and/or spinal cord compression) developed in 53 patients (37.1%). Development of SREs was significantly associated with metachronous BM (hazard ratio (HR) 2.04; p = 0.04), localization of BM to cervical spine (HR 3.89; p = 0.01), and lack of avid RAI uptake (HR 2.66; p = 0.02). Thirty-nine patients (27.3%) died in correlation with development of SREs (HR 6.97; p = 0.006) and localization of BM to the hip (HR 3.86; p = 0.02). Moreover, overall mortality was significantly decreased by RAI therapy (HR 0.10; p = 0.02), whereas no significant effects were induced by bone-active drugs (p = 0.36), external radiotherapy (p = 0.54), and surgery (p = 0.43) of BM. CONCLUSIONS: SREs are very frequent in BM from DTC and they impact patient survival. In the real life, the use of bone-active drugs is currently limited to zoledronate in patients with pre-existing SREs. In this clinical setting, RAI therapy, but not zoledronate, decreased mortality.

Impact of imaging protocol on left ventricular ejection fraction using gated-SPECT myocardial perfusion imaging.

BACKGROUND: There are limited data on the impact of the imaging protocol (single-day stress-rest, SD, vs. dual-day, DD) on the change in left ventricular (LV) ejection fraction (EF) (post-stress-rest) in relation to ischemia and on outcome. METHODS: Using propensity score matching procedure, 490 of 1121 patients with known CAD, undergoing a SD or a DD in a multicenter study, were evaluated. Stress and rest gated-SPECT myocardial perfusion imaging was used to quantify LV perfusion, EF, and volumes. Outcome was assessed at an average follow-up time of 3.2 years. RESULTS: Post-stress LVEF in SD and DD were comparable across all degrees of ischemia. The change in LVEF in patients with severe ischemia was, however, higher in the DD protocol, independent of the extent of CAD. At follow-up, 240 patients (49.0%) required coronary revascularization (CR) and 52 patients (10.6%) had hard events. The ischemic burden was independently associated with CR and hard-events; the post-stress LVEF was associated with CR but the change in EF was not predictive of either CR or hard events. CONCLUSIONS: In patients with severe ischemia, underestimation of post-stress myocardial stunning could be observed with the SD protocol. Post-stress LVEF and the extent ischemia, but not the change in EF, are predictive of CR and hard events.

Diagnostic role of (18)F-FDG-PET or PET/CT in salivary gland tumors: A systematic review.

Salivary gland tumors are rare neoplasms that have not been extensively studied with (18)F-FDG-PET- or PET/CT up to now. This review aims to evaluate the diagnostic performance of PET in this particular setting, analyzing the available literature. A comprehensive literature search in the PubMed/MEDLINE, Embase and Scopus databases was performed including articles up to November 2014, resulting in the selection of 22 articles. The studies selected suggest that: (1) PET is not useful in discriminating benign from malignant SGTs because of the overlap of uptake in both conditions; (2) PET not only is complementary to conventional imaging techniques for the staging and restaging but in some cases could also be superior to them; (3) PET may often have a highly positive impact on clinical decision making. Despite many limitations affecting the analysis, PET seems to be useful in SGTs. However, more extensive studies and cost-effectiveness analyses are desirable to determine its correct position in the diagnostic flow chart.

Applicability of the appropriate use criteria for SPECT myocardial perfusion imaging in Italy: preliminary results.

PURPOSE: Clinical applicability of the appropriate use criteria for SPECT myocardial perfusion imaging has not yet been evaluated in Italy. We investigated the applicability of the Appropriate Use Criteria (AUC) in Italy. METHODS: The indications for testing were prospectively recorded in three different nuclear cardiology laboratories: a general hospital, an academic hospital, and a tertiary centre. Indications were categorized as appropriate, uncertain or inappropriate according to the 2009 AUC; the specialty of the ordering physician was also noted. SPECT results were classified as: normal, probably normal, uncertain, probably abnormal, abnormal. The presence and severity of ischaemia were also noted. RESULTS: Over a 9-month period, 2,134 patients (age 67 ± 10 years, 68 % men) were evaluated (62 % exercise stress test). On average, there were 700 (84 %) appropriate, 73 (7 %) inappropriate and 93 (9 %) uncertain tests. The rates for the appropriateness of indications were comparable in men and women (84 % and 83 %, not significant). As expected, the rate of nonnormal studies was higher (58 %) for appropriate than for inappropriate (33 %) indications. Appropriateness was lower in the tertiary centre (74 %), and uncertain (16 %) and inappropriate (10 %) indications were more common; this was related to the higher rate of outpatients scheduled by nonhospital cardiologists (37 %). The most common indications associated with inappropriate testing were: chest pain, low likelihood of coronary artery disease, interpretable ECG and able to exercise (29 %), and asymptomatic <2 years after percutaneous coronary intervention (24 %). CONCLUSION: In this preliminary evaluation of the AUC in Italy, the majority of studies were classified as appropriate, but a consistent proportion of scheduled SPECT studies, particularly by nonhospital cardiologists, were still categorized as uncertain or inappropriate. Educational approaches should be implemented to reduce the rate of less appropriate examinations. However, a substantial proportion (33 %) of inappropriate studies were classified as nonnormal, with 26 % of these patients having ischaemia.

Nature versus nurture in frontotemporal lobar degeneration: the interaction of genetic background and education on brain damage.

BACKGROUND: Frontotemporal lobar degeneration (FTLD) is a progressive neurodegenerative disorder with a strong genetic background. It has been reported that modifiable factors, i.e. education (E), might act as proxies for reserve capacity. OBJECTIVE: To evaluate the impact of genetic background (positive family history, FH) on reserve mechanisms, by measuring regional cerebral blood flow (rCBF) correlates in FTLD patients. METHODS: 145 FTLD patients were recruited and underwent clinical, neuropsychological, behavioral assessment, and SPECT study. The main effect of E and FH on rCBF was evaluated. To test the potential interaction between the E and rCBF in FTLD patients with or without positive FH, a difference of slope analysis in the two groups was calculated. All the analyses were controlled for disease severity (Clinical Dementia Rating Scale, FTD-CDR). RESULTS: A main effect of education (E+ < E-) in frontal regions was reported, and high genetic loading (FH+ < FH-) was associated with a greater bilateral temporoparietal hypoperfusion. Evaluating the relationship between E and rCBF, a greater hypoperfusion of cingulate region in FH+ as compared to FH- was observed. DISCUSSION: Reserve mechanisms are available also in presence of an unfavorable genetic status. However, these compensatory mechanisms are modulated by the interaction with genetic factors.

¹³¹I treatment of toxic nodular goiter under combined thyrostatic-thyromimetic medication is at low risk of late hypothyroidism.

AIM: Treatment of toxic nodular goiter with ¹³¹I is a first-line therapy for hyperthyroidism. To avoid a thyrotoxic storm, ¹³¹I is usually administered after pretreatment with antithyroid drugs, with thyroid-stimulating hormone (TSH) increase and functional recruitment of inhibited normal tissue. Therefore, both autonomous nodule(s) and normal tissue are irradiated. This may be a reason for late hypothyroidism occurring in 15-25% of patients. This study aimed at assessing different pretreatment modalities with combined methymazole and triiodothyronine, achieving euthyroidism with suppressed TSH. METHODS: After diagnosis of autonomously functioning toxic nodule, patients were subjected to thyrostatic medication. Two months later, TSH was checked; if >0.5 mU/L triiodothyronine treatment was associated. After 2 more months, if the TSH level was suppressed, patients received ¹³¹I-therapy. A total of 149 patients were consecutively enrolled, 41 of whom with uninodular and 108 with multinodular goiter. They were evaluated at diagnosis, pretreatment, 3 and 6 months after therapy and at late follow-up (6.8+/-4.2 years; range: 1-22 years). RESULTS: Administered activity was calculated according to ¹³¹I uptake and gland weight. Methymazole was discontinued 6 days before treatment and T3 was maintained until administration of ¹³¹I-therapy. Euthyroidism was achieved in 88% of patients. At late follow-up, subclinical hypothyroidism was observed in 10 patients (6.7%) and overt hypothyroidism in 5 patients (3.3%). No pathological consequences or side effects of ¹³¹I-therapy were found during the 6.8+/-4.2 year follow-up period. CONCLUSION: Treatment of toxic nodular goiter with ¹³¹I-therapy, under combined thyrostatic-thyromimetic treatment is a simple, safe, well-tolerated, and effective procedure.

Revisiting brain reserve hypothesis in frontotemporal dementia: evidence from a brain perfusion study.

BACKGROUND: Literature data on Alzheimer's disease suggest that years of schooling and occupational level are associated with a reserve mechanism. No data on patients with behavioral variant frontotemporal dementia (bvFTD) are available yet. OBJECTIVE: To evaluate the impact of education, occupation, and midlife leisure activities on brain reserve in bvFTD. METHODS: Fifty-four bvFTD patients entered the study and underwent neuropsychological and behavioral assessment, including the FTD-modified Clinical Dementia Rating for FTD (FTD-modified CDR), and SPECT imaging. We tested for the linear correlation of educational and occupational level, and midlife leisure activities with regional cerebral blood flow (rCBF), controlling for demographic variables (age and gender) and for cognitive performance (FTD-modified CDR) (statistical parametric mapping). RESULTS: A significant relationship between higher educational and occupational attainments and lower rCBF in medial frontal cortex and dorsolateral frontal cortex, bilaterally, was found (p < 0.005). When midlife leisure activities were considered, no correlation was found. The correlation between a reserve index, accounting for both educational and occupational level, and rCBF showed the same pattern of hypoperfusion. CONCLUSIONS: This study suggests that education and occupation act as proxies for reserve capacity in bvFTD. These lifestyle attainments may counteract the onset of this genetic-based disease in at-risk individuals.

Combined 99mTc-ECD SPECT and neuropsychological studies in MCI for the assessment of conversion to AD.

Identifying pre-clinical Alzheimer's disease (AD) in subjects with mild cognitive impairment (MCI) is a major issue in clinical diagnosis. Establishing a combination of predictive markers from different fields of research might help in increasing the diagnostic accuracy. Aim of this study was to evaluate the potential role of 99mTc-ECD single photon emission computed tomography (SPECT) and memory scores in predicting conversion to AD in MCI subjects. Thirty-one MCI subjects underwent a clinical and neuropsychological examination, and a regional cerebral blood flow (rCBF) SPECT scan at baseline. Subjects had been followed periodically through 2 years in order to monitor the progression of cognitive symptoms. Canonical variate analysis of principal components was able to separate all subjects who converted to AD from those who remained stable, the former being characterized by a specific hypometabolic pattern, involving the parietal and temporal lobes, precuneus, and posterior cingulate cortex. Canonical correlation analysis of combined baseline memory deficits and rCBF SPECT images identified pre-clinical AD with a sensitivity and specificity of 77.8%. The pattern of hypoperfusion 99mTc-ECD SPECT and the severity of memory deficits predict the risk of progression to probable AD dementia in MCI subjects.