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Pericardial synovial sarcoma is a rare malignancy. We report the case of a patient who was referred to our institution for a large pericardial effusion requiring pericardiocentesis. CT imaging revealed an inhomogeneous pericardial mass beside the right atrium, and then a PET/CT scan was performed. Standard images were inconclusive whether delayed images showed an FDG-avid pericardial lesion that was surgically removed with histological diagnosis of a poorly differentiated biphasic synovial sarcoma. When considering mediastinal or pericardial mass, a delayed PET/CT may improve lesion-to-background contrast by reducing blood pool activity.

F-Fluoro-ethyl-choline (F-FCH) PET/CT is widely used to study patients affected by prostate cancer. However, F-FCH may be taken-up by other neoplastic diseases, infections, and non-infective inflammatory processes. While this behavior may be an opportunity to study different diseases, on the other hand, this condition brings with it the source of error in the evaluation of the images. Here we present the case of a meningeal inflammatory pseudotumor evidenced by F-FCH.

Objective The aim of the study was to assess the value and potential pitfalls of Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) in patients with suspected pancreatic neuroendocrine neoplasms (pNEN). Methods Consecutive patients referred for Ga-DOTANOC PET/CT for suspected pNEN between May 1, 2011, and October 31, 2014, were retrospectively assessed. Scan data were compared with cytological/histological final diagnosis. Pancreatic neuroendocrine neoplasm detection rate was determined on per-patient and per-lesion basis. Maximum standardized uptake values of lesions were determined. Results Fifty-eight patients with 65 lesions were enrolled. Twelve patients had nonconfirmed diagnosis; of these, 7 were positive and 5 negative at PET/CT. Of 46 patients with confirmed diagnosis, 36 had pNEN; of these, 33 were positive, 1 negative, and 2 nonevaluable at PET/CT. Ten patients had non-NE lesions, of which 8 were positive, 1 negative, and 1 nonevaluable at PET/CT. Of 48 patients with positive PET/CT, 8 proved to have non-NE lesions, of which 6 were intrapancreatic accessory spleen. No significant maximum standardized uptake values difference was found between pNEN and non-NE lesions. Conclusions Intrapancreatic accessory spleen is an important pitfall in Ga-DOTANOC PET/CT for suspected pNEN. Cytological/histological confirmation is mandatory before any surgical procedure is undertaken.

The diagnostic work-up of locally advanced rectal cancer (LARC) has also changed thanks to recent advances in positron emission tomography-computed tomography (PET-CT) and its increasing availability. Several studies showed that FDG PET-CT accurately changed the stage with a subsequent alteration in therapy in almost one-third of patients. Moreover, FDG PET-CT capable to predict the effect of preoperative chemoradiation as well as survival.

To evaluate whether metabolic changes in the primary tumour during and after preoperative radiochemotherapy (RCT) can predict the histopathological response in patients with locally advanced rectal cancer as well as disease-free survival (DFS) and overall survival (OS).Consecutive patients with cT2-4 N0-2 rectal adenocarcinoma were included. (18)F-FDG PET/CT was performed at baseline, at the end of the second week of RCT (early PET/CT) and before surgery (late PET/CT). The PET/CT results were compared with histopathological data (ypT0 N0 vs. ypT1-4 N0-2 as well as TRG1 vs.TRG2-5) and survival.The study included 126 patients. Among 124 patients in whom TNM classification was available, 28 (22.6 %) were ypT0 N0, and among all 126 patients, 31 (24.6 %) were TRG1. The areas under the curve of the early response index (RI) for identifying non-complete pathological response (non-cPR) were 0.74 (95 % CI 0.61 - 0.87) for ypT1-4 N0-2 patients and 0.75 (95 % CI 0.62 - 0.88) for TRG2-5 patients. The optimal cut-off for differentiating patients with non-cPR and cPR was found to be a reduction of 61.2 % (83.1 % sensitivity and 65 % specificity in ypT1-4 N0-2 patients; 85.4 % sensitivity and 65.2 % specificity in TRG2-5 patients). The optimal cut-off for late RI could not be found. The qualitative analysis of images obtained after RCT demonstrated 81.5 % sensitivity and 61.3 % specificity in predicting TRG2-5. After a median follow-up of 68 months, the low number of patients with local/distant recurrence or who had died did not allow the value of PET/CT for predicting DFS and OS to be calculated.The early assessment of response to RCT by (18)F-FDG PET/CT can predict non-cPR allowing practical modification of preoperative treatment. Conversely, late RI is not sufficiently accurate for guiding the decision as to whether local excision or even observation is appropriate in an individual patient. Qualitative analysis of late PET/CT images is also not sensitive enough alone to rule out the presence of residual disease.

This study aimed to assess the value of dual-timepoint 18F-FDG PET/CT in the prediction of lymph node (LN) status in patients with invasive vulvar cancer (VC) scheduled for inguinofemoral LN dissection. Methods: From April 2013 to July 2015, all consecutive patients with VC scheduled for inguinofemoral LN dissection were prospectively enrolled. All patients underwent a preoperative whole-body 18F-FDG PET/CT scan at 1 h (standard examination) and an additional scan from T11 to the groins at 3 h (delayed examination) after 18F-FDG injection. On both scans, each groin was visually scored 0 or 1 concerning 18F-FDG LN uptake relative to background. Semiquantitative analysis included SUVmax and the corresponding retention index of SUVmax, measured on both scans. The optimal cutoff value of these parameters was defined using a receiver-operating-characteristic analysis. Histopathology was the standard of reference. Results: Thirty-three patients were included, with a total of 57 groins dissected and histologically evaluated. At histopathology, 21 of 57 (37%) groins contained metastatic LNs. Concerning visual score, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were 95.2%, 75%, 96.4%, 69%, and 82.5% on standard scanning and 95.2%, 77.8%, 96.6%, 71.4%, and 84.2% on delayed scanning, respectively. At receiver-operating-characteristic analysis, sensitivity and specificity were 95.2% and 77.8% on standard and delayed 18F-FDG PET/CT for an SUVmax cutoff of greater than 1.32 and 1.88, respectively, and 95.2% and 80% for a retention index of SUVmax cutoff of greater than 0. Conclusion: Standard 18F-FDG PET/CT is an effective preoperative imaging method for the prediction of LN status in VC, allowing the prediction of pathologically negative groins and thus the selection of patients suitable for minimally invasive surgery. Delayed 18F-FDG PET/CT did not improve the specificity and the positive predictive value in our series. Larger studies are needed for a further validation.

Positron emission tomography-computed tomography (PET-CT) with (18)F-fluorodeoxyglucose (FDG) has emerged as a rapidly evolving diagnostic tool for infectious diseases. However, the optimal imaging time in this clinical setting is not clear yet. The aim of this study is to investigate whether delayed (3 hours) FDG PET-CT could increase the diagnostic accuracy of this technique compared to standard (1 hour) imaging in the detection of septic foci involving the pocket and/or pacing leads in patients with suspected cardiovascular implantable electronic device (CIED) infection scheduled for device removal.Twenty-seven patients underwent standard and delayed imaging. PET-CT results were compared to bacteriological cultures after CIED removal. Fifteen controls free of infection underwent PET-CT imaging as part of investigation of malignancy. The diagnostic accuracy of delayed imaging was significantly higher than 1-hour scan for lead infection (70% vs 51%, P = .024). No significant difference was found between standard and delayed diagnostic accuracy for pocket or device infection. Semi-quantitative analysis showed that mean pocket and lead target-to-background ratio were significantly higher on delayed compared to standard imaging (3.7 ± 1.9 vs 1.6 ± 1.1, P = .0002; 3.0 ± 1.3 vs 0.7 ± 1.0, P = .01).Delayed FDG PET-CT imaging should be considered at least in patients with negative 1-hour scan and founded suspicion of pacing lead infection.

A 40-year-old female patient with suspected multifocal extra-adrenal paraganglioma, on the basis of biochemical, genetic, and conventional imaging data, underwent 18F-FDG, 18F-DOPA and 68Ga DOTANOC PET/CT. FDOPA- and FDG-PET/CT detected a multifocal mediastinal and cervical paraganglioma. 68Ga-DOTANOC PET/CT detected 2 additional lesions compared to the other PET/CT methods. In our case, somatostatin receptor PET/CT with 68Ga-DOTANOC correctly assessed the extent of the disease in a patient with multifocal paraganglioma.

To systematically review and meta-analyse literature data on the diagnostic performance of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) in patients with Ewing sarcoma family tumours (ESFT). PubMed/MEDLINE, Embase and Scopus databases were searched for articles that evaluated FDG-PET and PET/CT in patients with ESFT from inception to 31 May 2011. Studies that fulfilled the three following criteria were included in the systematic review: FDG-PET or PET/CT performed in patients with ESFT; articles about the diagnostic accuracy of FDG-PET and PET/CT; sample size of at least 10 patients with ESFT were included. Studies in which there were sufficient data to reassess sensitivity and specificity of FDG-PET or PET/CT in ESFT were included in the meta-analysis, excluding duplicate publications. Finally, pooled sensitivity, pooled specificity and area under the receiver operating characteristic (ROC) curve of FDG-PET or PET/CT in ESFT were calculated. We found 13 studies comprising a total of 342 patients with ESFT. The main findings of the studies included are presented. The meta-analysis of five selected studies provided these results about FDG-PET and PET/CT in ESFT: pooled sensitivity: 96% (95% confidence interval [CI] 91–99%); pooled specificity: 92% (95% CI 87–96%); area under the ROC curve: 0.97. With regard to the staging and restaging of patients with ESFT, the sensitivity, specificity and accuracy of FDG-PET and PET/CT are high; the combination of FDG-PET or PET/CT with conventional imaging is a valuable tool for the staging and restaging of ESFT and has a relevant impact on the treatment strategy plan.

We report the case of a 53-year-old man with a chronic periaortitis (CP) in whom Fluorine-18-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has been useful in assessing the disease extent at diagnosis, in evaluating the treatment response, in diagnosing the relapse, and in monitoring the disease activity during follow-up (Fig. 1). This case highlights the usefulness of FDG-PET/CT at different times in patients with CP. Fig. 1 A 53-year-old man was admitted to our hospital for a suspected chronic periaortitis (CP) based on clinical (abdominal pain), laboratory data (increased serological inflammatory markers, such as erythrocyte sedimentation rate [ESR] and C reactive protein ... CP is a rare inflammatory disorder that affects the abdominal aorta and the retroperitoneum [1–3]. Imaging procedures are essential to diagnose and monitor the disease course [1–3]. Ultrasonography may be used as first-line screening test, and is particularly useful to monitor patients with hydronephrosis and aortic aneurysms. However, CT or magnetic resonance imaging (MRI) of the abdomen are currently considered the investigations of choice to diagnose CP [1–3]. In active CP, the periaortic mass usually enhances on CT and MRI. Both these methods can be used to monitor the disease course of CP and to evaluate response to treatment. A note of caution: signs of vasculitis seen on MRI and CT may persist for some time, despite achievement of clinical remission. A further limitation of abdominal CT and MRI is that neither technique can detect vasculitis in vessels other than the abdominal aorta, which has been described in 43 % of patients with CP [1]. FDG-PET/CT has been proposed as useful tool in inflammatory diseases, such as aortitis, because metabolic changes assessed by FDG-PET usually precede morphological changes assessed by conventional imaging methods [4–8]. Our case highlights the usefulness of FDG-PET/CT at different times in patients with CP. This method may be useful in assessing disease activity and extent at diagnosis, in evaluating the treatment response, in diagnosing the relapse, and in monitoring the disease during follow-up.

We report a case of a patient with relapse of POEMS syndrome (peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasma proliferative disorder, skin changes) that occurred 6 years after an autologous peripheral blood stem cell transplantation. F-18 FDG PET/CT showed several hypermetabolic as well as nonhypermetabolic bone lesions. Based on these findings, the patient was referred for radiotherapy to the hypermetabolic bone lesions. After autologous peripheral blood stem cell transplantation, F-18 FDG PET/CT may play a pivotal role in detecting new bone lesions in patients with POEMS syndrome, which may be treated by a focalized radiotherapy and/or systemic therapy.

Differential diagnosis between Parkinson’s disease (PD) and other Parkinsonism using clinical criteria or imaging methods is often difficult. The purpose of this study is to systematically review and meta-analyze published data about the diagnostic performance of myocardial innervation imaging using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in differential diagnosis between PD and other Parkinsonism. A comprehensive computer literature search of studies published through March 2011 regarding MIBG scintigraphy in patients with PD and other Parkinsonism was performed in PubMed/MEDLINE and Embase databases. Only studies in which MIBG scintigraphy was performed for differential diagnosis between PD and other Parkinsonism were selected. Pooled sensitivity, pooled specificity and area under the ROC curve were calculated to measure the accuracy of MIBG scintigraphy in differential diagnosis between PD and other Parkinsonism. Nineteen studies comprising 1,972 patients (1,076 patients with PD, 117 patients with other Lewy body diseases and 779 patients with other diseases) were included in this meta-analysis. The pooled sensitivity of MIBG scintigraphy in detecting PD was 88% (95% CI 86–90%); the pooled specificity of MIBG scintigraphy in discriminating between PD and other Parkinsonism was 85% (95% CI 81–88%). The area under the ROC curve was 0.93. In patients with clinically suspected PD, myocardial innervation imaging demonstrated high sensitivity and specificity. MIBG scintigraphy is an accurate test in this setting. Nevertheless, possible causes of false-negative and false-positive results should be kept in mind when interpreting the scintigraphic results.