Neurological complications of rotavirus infection in children: A systematic review and meta-analysis.

AIM: To systematically review the clinical features and outcomes of paediatric patients developing neurological complications associated with a rotavirus infection. METHODS: A systematic literature review and meta-analysis was performed, including articles published from 1984 to 2020. Neurological complications were classified into four groups: encephalitis, cerebellitis, encephalo-cerebellitis and benign convulsions with mild gastroenteritis (CwG). RESULTS: Out of 68 reports that fulfilled the research criteria, 99 cases of CwG, 39 cases of encephalitis, 18 cases of encephalo-cerebellitis and five cases of cerebellitis were collected. Ninety-five patients were from Asia. Median age was 22 (IQR 14-29) months, and the children who developed CwG were significantly younger (19, IQR 12-24 months, p < 0.0001) than the others. Status epilepticus was observed in 23% and 5% of the encephalitis and CwG groups respectively. The most frequently described neuroimaging finding were lesions of the splenium of corpus callosum. Four deaths were reported in the encephalitis group, whereas no fatal events were described in the other groups. Among the surviving children, the encephalo-cerebellitis group showed the most severe long-term outcome. All cases of CwG recovered completely. CONCLUSION: Older age at diagnosis and the development of encephalo-cerebellitis are associated with a higher risk of long-term complications.

A systematic review of contemporary phase I trials in patients with lymphoma.

We performed a systematic review of phase I trials specifically designed for lymphoma patients. PubMed and Cochrane Library databases were searched using (lymphoma*) AND (phase 1) and publication date 2015-2020 to identify phase I dose-finding trials including a majority of lymphoma patients. Eighty-two trials (n = 3289 lymphoma patients) were included: 46 (55%) enrolled only lymphoma patients, 34 (41%) included also other hematologic malignancies, 2 (2%) solid tumors. Forty-six trials (56%) evaluated a combination (in 25 addition of experimental drug to standard therapy). Seven trials (9%) enrolled untreated patients. Among trials reporting activity in lymphoma patients, 74% (n = 57) reported an overall response rate ≥ 30%. All trials reported grade ≥ 3 adverse events; however, rates were not comparable across trials. Thirty-one treatment-related deaths in lymphoma patients were reported (overall treatment-related grade 5 adverse events rate 0.94%). Phase I trials designed for lymphoma patients were generally safe and the majority reported overall response rate ≥ 30%.

A systematic review of phase II trials exploring anti-PD-1/PD-L1 combinations in patients with solid tumors.

BACKGROUND: A high number of combinations of PD-1/PD-L1 inhibitors with other anti-cancer therapies are in clinical development. The usefulness of phase II trials in evaluating their efficacy and safety is unclear. MATERIALS AND METHODS: We performed a systematic search on PubMed and Cochrane Library for phase II trials of PD-1/PD-L1 inhibitors in combination with other anti-cancer therapies (systemic therapy and/or radiotherapy) published between January 1st 2018 and December 31st 2020. Study design, primary endpoint and main outcomes were registered for each paper. RESULTS: 119 articles reporting on 65 regimens were included in our analysis. Backbone agents were more frequently PD-1 inhibitors (pembrolizumab = 47, nivolumab = 41, camrelizumab = 3) followed by anti-PD-L1 (durvalumab = 19, atezolizumab = 6, avelumab = 3). Therapeutic partners were other immunotherapeutic agents (n = 46), targeted therapies (n = 40), chemotherapy (n = 22) or radiotherapy (n = 11). The majority of articles reported on single-arm trials (n = 87, 73%) and response rate was the most frequent primary endpoint (n = 69, 58%). Objective responses, registered in 109 (92%) articles, ranged between 0% and 91%. The incidence of grade 3 or higher treatment-related adverse events, clearly reported in 97 (82%) articles, spanned from 0 to 100%. Five combinations received regulatory approval by Food and Drug Administration or European Medicine Agency for 9 different indications, based on the results of a phase II trial (n = 3) or on a confirmatory phase III trial (n = 6). CONCLUSIONS: The landscape of phase II trials evaluating PD-1/PD-L1 inhibitors with other anticancer therapies is heterogeneous. Combinations of two immunotherapeutic agents have been the most investigated. Only a minority of indications (8%) granted regulatory approval.

Diagnostic value of [18F]FDG-PET/CT for treatment monitoring in large vessel vasculitis: a systematic review and meta-analysis.

PURPOSE: Monitoring disease activity in patients with large vessel vasculitis (LVV) can be challenging. [18F]FDG-PET/CT is increasingly used to evaluate treatment response in LVV. In this systematic review and meta-analysis, we aimed to summarize the current evidence on the value of [18F]FDG-PET/CT for treatment monitoring in LVV. METHODS: PubMed/MEDLINE and the Cochrane library database were searched from inception through October 21, 2020. Studies containing patients with LVV (i.e. giant cell arteritis, Takayasu arteritis and isolated aortitis) that received treatment and underwent [18F]FDG-PET/CT were included. Screening, full-text review and data extraction were performed by 2 investigators. The risk of bias was examined with the QUADAS-2 tool. Meta-analysis of proportions and diagnostic test accuracy was performed by a random-effects model and bivariate model, respectively. RESULTS: Twenty-one studies were included in the systematic review, of which 8 studies were eligible for meta-analysis. Arterial [18F]FDG uptake decreased upon clinical remission in longitudinal studies. High heterogeneity (I2 statistic 94%) precluded meta-analysis of the proportion of patients in which the scan normalized during clinical remission. Meta-analysis of cross-sectional studies indicated that [18F]FDG-PET/CT may detect relapsing/refractory disease with a sensitivity of 77% (95%CI 57-90%) and specificity of 71% (95%CI 47-87%). Substantial heterogeneity was observed among the cross-sectional studies. Both variation in clinical aspects and imaging procedures contributed to the heterogeneity. CONCLUSION: Treatment of LVV leads to reduction of arterial [18F]FDG uptake during clinical remission. [18F]FDG-PET/CT has moderate diagnostic accuracy for detecting active LVV. [18F]FDG-PET/CT may aid treatment monitoring in LVV, but its findings should be interpreted in the context of the clinical suspicion of disease activity. This study underlines the relevance of published procedural recommendations for the use of [18F]FDG-PET/CT in LVV.

Diagnostic value of [18F]FDG-PET/CT in polymyalgia rheumatica: a systematic review and meta-analysis.

PURPOSE: Polymyalgia rheumatica (PMR) can be difficult to diagnose. Whole-body [18F]FDG-PET/CT allows for a comprehensive evaluation of all relevant articular and extra-articular structures affected by PMR. We aimed to summarize current evidence on the diagnostic value of [18F]FDG-PET/CT for a diagnosis of PMR. METHODS: PubMed/MEDLINE and the Cochrane Library database were searched from inception through May 31, 2020. Studies containing patients with PMR who underwent [18F]FDG-PET/CT were included. Screening and full-text review were performed by 3 investigators and data extraction by 2 investigators. Risk of bias was examined with the QUADAS-2 tool. Diagnostic test meta-analysis was performed with a bivariate model. RESULTS: Twenty studies were included in the systematic review, of which 9 studies (n = 636 patients) were eligible for meta-analysis. [18F]FDG positivity at the following sites was associated with a diagnosis of PMR: interspinous bursae (positive likelihood ratio (LR+) 4.00; 95% CI 1.84-8.71), hips (LR+ 2.91; 95% CI 2.09-4.05), ischial tuberosities (LR+ 2.86; 95% CI 1.91-4.28), shoulders (LR+ 2.57; 95% CI 1.24-5.32) and sternoclavicular joints (LR+ 2.31; 95% CI 1.33-4.02). Negative likelihood ratios (LR-) for these sites, as well as the greater trochanters, were all less than 0.50. Composite [18F]FDG-PET/CT scores, as reported in 3 studies, provided a pooled LR+ of 3.91 (95% CI 2.42-6.32) and LR- of 0.19 (95% CI 0.10-0.36). Moderate to high heterogeneity was observed across the studies, mainly due to differences in patient selection, scanning procedures and/or interpretation criteria. CONCLUSION: Significant [18F]FDG uptake at a combination of anatomic sites is informative for a diagnosis of PMR. [18F]FDG-PET/CT might be an important diagnostic tool in patients with suspected PMR. This study also highlights the need for adherence to published procedural recommendations and standardized interpretation criteria for the use of [18F]FDG-PET/CT in PMR.

The value of 18F-FDG PET/CT for the diagnosis of device-related infections in patients with a left ventricular assist device: a systematic review and meta-analysis.

BACKGROUND: Left ventricular assist devices (LVADs) are increasingly used for the treatment of advanced heart failure. LVADs improve quality of life and decrease mortality, but the driveline carries substantial risk for major infections. These device-related LVAD and driveline infections are difficult to diagnose with conventional imaging. We reviewed and analysed the current literature on the additive value of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) imaging for the diagnosis of LVAD-related infections." MATERIALS/METHODS: We performed a systematic literature review using several databases from their inception until the 31st of December, 2019. Studies investigating the diagnostic performance of FDG-PET/CT in patients with suspected LVAD infection were retrieved. After a bias risk assessment using QUADAS-2, a study-aggregate meta-analysis was performed on a per examination-based analysis. RESULTS: A total of 10 studies were included in the systematic review, eight of which were also eligible for study-aggregate meta-analysis. For the meta-analysis, a total of 256 FDG-PET/CT scans, examining pump/pocket and/or driveline infection, were acquired in 230 patients. Pooled sensitivity of FDG-PET/CT was 0.95 (95% confidence interval (CI) 0.89-0.97) and pooled specificity was 0.91 (95% CI 0.54-0.99) for the diagnosis of device-related infection. For pump/pocket infection, sensitivity and specificity of FDG-PET/CT were 0.97 (95%CI 0.69-1.00) and 0.93 (95%CI 0.64-0.99), respectively. For driveline infection, sensitivity and specificity were 0.96 (95%CI 0.88-0.99) and 0.99 (95%CI 0.13-1.00) respectively. Significant heterogeneity existed across studies for specificity, mostly caused by differences in scan procedures. Predefined criteria for suspicion of LVAD and/or driveline infection were lacking in all included studies. CONCLUSIONS: FDG-PET/CT is a valuable tool for assessment of device-related infection in LVAD patients, with high sensitivity and high, albeit variable, specificity. Standardization of FDG-PET/CT procedures and criteria for suspected device-related LVAD infections are needed for consistent reporting of FDG-PET/CT scans.

FNA indication according to ACR-TIRADS, EU-TIRADS and K-TIRADS in thyroid incidentalomas at 18F-FDG PET/CT.

OBJECTIVE: Focal thyroid incidentaloma (TI) occurs in a 2% of 18F-FDG PET/CT and about one-third of TIs is cancer. Due to the lack of evidence on the optimal management of TI, current guidelines suggest performing fine-needle aspiration cytology (FNA). The study aim was to evaluate the reliability of ACR-TIRADS, EU-TIRADS, and K-TIRADS in indicating FNA in TIs. DESIGN: We retrospectively reviewed 18F-FDG PET/CT TIs recorded during the period 2016-2019. Enrolled were TIs with histologic outcome and autonomous nodules. Cases with uncertain matching between 18F-FDG PET/CT, US/scintiscan and histology were excluded. RESULTS: Eighty TIs at 18F-FDG PET/CT (median size 17 mm, median SUVmax 7.85) were included; a 26.2% was cancer. The percentage of nodules classified as high risk according to ACR-TIRADS, EU-TIRADS, and K-TIRADS was 20%, 30%, and 29.8%, respectively. The cancer prevalence in high-risk class was 56.2%, 66.7%, and 65.2% in ACR-TIRADS, EU-TIRADS, and K-TIRADS, respectively. ACR-TIRADS had the lowest number of cases with FNA indication (48%) and the K-TIRADS, the highest one (75%). Evaluating the reliability of the three systems in indicating FNA, we found a 100% sensitivity and NPV for EU-TIRADS and K-TIRADS; while all the three systems showed poor specificity and PPV. CONCLUSION: All TIRADSs were reliable to stratify the risk of cancer in focal TI. Comparing their reliability in indicating FNA, we found a good performance of EU-TIRADS and K-TIRADS. Considering the high cancer percentage expected in this setting of patients, those TIRADS with higher propensity to indicate FNA should be preferred.

18F-FDG-PET/CT Imaging in Advanced Glottic Cancer: A Tool for Clinical Decision in Comparison with Conventional Imaging.

This study assessed the role of 18F-FDG PET-CT (PET/CT) to detect the cartilage and paraglottic infiltration in advanced glottic cancer comparing the results with those of conventional imaging (CI) (contrast-enhanced computed tomography and/or magnetic resonance). In addition, we assessed the prognostic value of quantitative parameters, measured on baseline PET/CT, in terms of event-free survival (EFS) and overall survival (OS). We retrospectively analyzed 27 patients with glottic squamous cell carcinoma stage III and IVA, treated in our institute between 2010 and 2016, comparing PET/CT, performed for staging and radiotherapy planning, and CI findings. Cohen's K was used to compare concordance between PET/CT and CI. Imaging findings were correlated with endoscopic evaluation and histological reports (gold standard (GS)). All lesions shown by CI were also detected by PET/CT imaging, and in 5 cases, a better definition of local infiltration was achieved with PET/CT than CI (5 CT). Sensitivity, specificity, and accuracy of PET/CT and CT were 95%, 86%, and 93% and 70%, 86%, and 74% for, respectively. MRI showed sensitivity and specificity of 100%. One false-negative (FN) cases and 1 false-positive (FP) case were observed with PET/CT with no difference compared to MRI (10 cases). Six FN cases and 1 FP case were observed with CT. Cohen's K was 0.60 (PET vs. CI) and 0.80 (PET vs. GS). Patients were followed-up for at least 24 months to calculate EFS and OS. 13 local recurrence and 7 deaths were recorded. Among quantitative PET parameters, baseline MTV was the most powerful predictor of outcome. Our data suggest a reliable sensitivity and accuracy of PET/CT in the evaluation of local extension, proving a useful method for initial local staging in addition to the well-established role in lymph-node and distant sites assessment. Furthermore, pretreatment MTV provides better prognostic information than other PET/CT parameters.

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

Objetivo: Los sarcomas uterinos son tumores raros con mal pronóstico debido a las altas tasas de recurrencia. El papel actual de la 18F-FDG PET/TC en la vigilancia posterior a la terapia aún no está establecido. Material y metodos: Cuarenta y una mujeres con sarcoma uterino se sometieron a 73 estudios 18F-FDG PET/TC para la reestadificación en la presunta recurrencia o durante el seguimiento en pacientes asintomáticos. Los resultados histopatológicos y/o el seguimiento clínico/de imágenes durante al menos 12 meses se consideraron el estándar de referencia. Se calculó la precisión diagnóstica y el impacto clínico de la 18F-FDG PET/TC. Resultados: treinta y tres estudios 18F-FDG PET/TC fueron positivos, mientras que los 40 estudios restantes fueron negativos. La sensibilidad general, la especificidad, el valor predictivo positivo (VP+), el valor predictivo negativo (VP-) y la precisión de la 18F-FDG PET/TC fueron del 88%, 98%, 97%, 91% y 93%. Considerando pacientes con sospecha clínica o radiológica de recidiva (n=47) y durante el seguimiento (n=26) la sensibilidad y especificidad, VP+, VP− y precisión de 18F-FDG PET/TC fueron del 89%, 100%, 100%, 86% y 94%, y 80%, 95%, 80%, 95% y 92% respectivamente. La 18F-FDG PET/TC tuvo un impacto clínico positivo en 9/73 (12%) estudios y cambió el manejo clínico en 8/41 (20%) pacientes. Conclusion: La 18F-FDG PET/TC es un método preciso para la detección y localización de recidivas a distancia en pacientes con sarcoma uterino con buena sensibilidad y especificidad e impacto significativo en la toma de decisiones clínicas

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

Additional value of integrated 18F-choline PET/4D contrast-enhanced CT in the localization of hyperfunctioning parathyroid glands and correlation with molecular profile.

PURPOSE: The localization of hyperfunctioning parathyroid gland(s) (HPTG) in patients with primary hyperparathyroidism (PHPT) with negative or inconclusive first-line imaging is a significant challenge. This study aimed to evaluate the role of integrated 18F-choline PET/4D contrast-enhanced computed tomography (4DCeCT) in these patients, compare its detection rate and sensitivity with those of 18F-choline PET/CT and (4DCeCT), and analyse the association between choline metabolism and morphological, biochemical and molecular parameters of HPTG. METHODS: We prospectively enrolled 44 PHPT patients with negative or inconclusive first-line imaging. 18F-Choline PET/CT and 4DCeCT were performed at the same time, and integrated 18F-choline PET/4DCeCT images were obtained after coregistration. Experienced physicians examined the images. The SUVratio and degree of contrast enhancement were recorded for each positive finding. Histopathology, laboratory and multidisciplinary follow-up were used as the standard of reference. Both the detection rates and sensitivities of the three imaging modalities were calculated retrospectively. Immunohistochemistry was performed to evaluate the molecular profile of HPTGs. RESULTS: 18F-Choline PET/4DCeCT was positive in 32 of 44 patients with PHPT (detection rate 72.7%), and 31 of 31 surgically treated patients (sensitivity 100%). These results were significantly (p < 0.05) better than those of 18F-choline PET/CT (56.8% and 80%, respectively) and those of 4DCeCT (54.5 and 74%, respectively). A significant correlation between SUV and calcium level was found. In a multivariate analysis, only calcium level was significantly associated with 18F-choline PET/4DCeCT findings. SUVratio and Ki67 expression were significantly correlated. CONCLUSION: Integrated 18F-choline PET/4DCeCT should be considered as an effective tool to detect PHPT in patients with negative or inconclusive first-line imaging. Choline metabolism is correlated with both calcium level and Ki67 expression in HPTG.

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.

18F-FDG PET/CT for invasive fungal infection in immunocompromised patients.

BACKGROUND: Opportunistic invasive fungal infections (IFIs) comprise a heterogeneous spectrum of pathogens, whose early diagnosis remains challenging. Candida spp. and Aspergillus spp, the most frequent pathogens in immunocompromised patients, frequently affect lungs, liver, bone and skin. AIM: To evaluate the impact of 18F-FDG PET/CT in the management of immunocompromised patients with IFI. DESIGN: A single-center retrospective study included 51 immunocompromised patients with IFI diagnosis undergoing 83 18F-FDG PET/CTs. METHODS: Twenty-nine 18F-FDG PET/CTs were performed for primary work-up in 29 treatment-naïve patients. Fifty-four PET/CTs were performed during follow-up to confirm IFI suspicion in 22 patients who had anti-fungal drug therapy before PET/CT. When available, histological and/or microbiological criteria were used to assess IFI diagnosis. RESULTS: Aspergillus spp. and Candida spp. were the most frequent microorganisms responsible for IFI in our population. 18F-FDG PET/CT sensitivity, specificity, positive and negative predictive values, and global accuracy were 93%, 81%, 95%, 72% and 90%, respectively. 18F-FDG PET/CT influenced the diagnostic work-up at primary staging in 16/29 patients (55%) by assessing the extent of infection and targeting the diagnostic procedure. 18F-FDG PET/CT results during treatment induced anti-fungal drugs dosage increase and/or new drugs addition in 8/54 cases (15%) and contributed to the reduction of anti-fungal drugs dosage or treatment withdraws in 17 cases (31%). CONCLUSIONS: We recommend the utilization of 18F-FDG PET/CT to improve the primary staging work-up of immunocompromised patients with IFI and to assess treatment effectiveness or disease relapse. Both 18F-FDG PET/CT and conventional imaging should be integrated into a well-defined imaging diagnostic algorithm considering the clinical context and both strengths and limitations of each diagnostic modality.

Metástasis infrecuente de mesotelioma pleural detectada mediante 18F-FDG PET/TC de cuerpo entero / Uncommon distant metastasis of pleural mesothelioma detected by whole-body 18F-FDG PET/CT

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Caso inusual de tumor de origen desconocido detectado con 18F-FDG PET/TC: carcinoma de células claras de la glándula tiroides metastásico / Unusual case of tumor of unknown origin found by 18F-FDG PET/CT: Metastatic clear cell carcinoma of the thyroid gland

No disponible

Multimodal imaging in an unusual case of radionecrosis of the pubic symphysis / Imágenes multimodales en un caso inusual de radionecrosis de la sínfisis púbica

No disponible

Pulmonary talcosis caused by methadone misuse and mimicking primary lung cancer. FDG-PET/CT findings / Talcosis pulmonar por uso inadecuado de metadona que imita cáncer de pulmón. Hallazgos en FDG-PET/TC

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Thyroid nodules with indeterminate cytology: prospective comparison between 18F-FDG-PET/CT, multiparametric neck ultrasonography, 99mTc-MIBI scintigraphy and histology.

PURPOSE: To evaluate the role of (18)F-flurodeoxiglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) in predicting malignancy of thyroid nodules with indeterminate cytology. PATIENTS AND METHODS: We analysed 87 patients who have been scheduled to undergo surgery for thyroid nodule with indeterminate cytology. All patients underwent (18)F-FDG-PET/CT, multiparametric neck ultrasonography (MPUS), and (99m)Tc-methoxyisobutylisonitrile scintigraphy ((99m)Tc-MIBI-scan). Histopathology was the standard of reference. We compared the sensitivity (SE), specificity (SP), accuracy (AC), positive (PPV) and negative predictive (NPV) values of (18)F-FDG-PET/CT with those of (99m)Tc-MIBI-scan and MPUS in detecting cancer. Univariate and multivariate analyses evaluated the association between each diagnostic tool and histopathology. RESULTS: On histopathology, 69 out of 87 nodules were found to be benign and 18 to be malignant. The SE, SP, AC, PPV and NPV of (18)F-FDG-PET/CT were 94, 58, 66, 37 and 98% respectively. The SE, AC and NPV of (18)F-FDG-PET/CT were significantly higher than those of MPUS and (99m)Tc-MIBI-scan. The association of both positive (18)F-FDG-PET/CT and MPUS (FDG+/MPUS+) showed significantly lower SE (61% vs 94%) and NPV (88% vs 98%) than (18)F-FDG-PET/CT alone, but significantly higher SP (77% vs 58%). On univariate analysis, (18)F-FDG-PET/CT and the combination of FDG+/MPUS+ and of FDG+/MIBI- were all significantly associated with histopathology. On multivariate analysis, only FDG+/MIBI- was significantly associated with histopathology. CONCLUSION: The AC of (18)F-FDG-PET /CT in detecting thyroid malignancy is higher than that of (99m)Tc-MIBI-scan and MPUS. A negative (18)F-FDG-PET/CT correctly predicts benign findings on histopathology. The association of FDG+/MPS+ is significantly more specific than (18)F-FDG-PET/CT alone in identifying differentiated thyroid cancer. A positive (18)F-FDG-PET/CT is significantly associated with malignancy when qualitative (99m)Tc-MIBI-scan is rated as negative.