G. Pop

Management of large-vessel vasculitis with FDG-PET: a systematic literature review and meta-analysis.

AbstractWe aimed to clarify the role of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the management of large-vessel vasculitis (LVV), focusing on 3 issues which are as follows: describe and determine the different FDG-PET criteria for the diagnosis of vascular inflammation, the performance of FDG-PET for the diagnosis of large-vessel inflammation in giant cell arteritis (GCA) patients, and the performance of FDG-PET to evaluate the disease inflammatory activity in Takayasu arteritis (TA) patients.MEDLINE, Cochrane Library, and EMBASE database were searched for articles that evaluated the value of FDG-PET in LVV, from January 2000 to December 2013. Inclusion criteria were American College of Rheumatology criteria for GCA or TA, definition PET positivity threshold, and >4 cases included. Sensitivity (Se) and specificity (Sp) of FDG-PET for the diagnosis of large-vessel inflammation were calculated from each included individual study, and then pooled for meta-analysis with a random-effects model.Twenty-one studies (413 patients, 299 controls) were included in the systematic review. FDG-PET showed FDG vascular uptake in 70% (288/413) of patients and 7% (22/299) of controls. Only vascular uptake equal to or higher than the liver uptake was significantly different between GCA/TA patients and controls (P < 0.001). The meta-analysis of GCA patients (4 studies, 57 patients) shows that FDG-PET has high Se and Sp for the diagnosis of large-vessel inflammation in GCA patients in comparison to controls, with a pooled Se at 90% (95% confidence interval [CI], 79%–93%) and a pooled Sp at 98% (95% CI, 94%–99%). The meta-analysis of TA patients (7 studies, 191 patients) shows that FDG-PET has a pooled Se at 87% (95% CI, 78%–93%) and Sp at 73% (95% CI, 63%–81%) for the assessment of disease activity in TA, with up to 84% Sp, with studies using National Institutes of Health criteria as the disease activity assessment scale.FDG-PET showed good performances in the diagnosis of large-vessel inflammation, with higher accuracy in GCA patients than in TA patients. Although a vascular uptake equal to or higher than the liver uptake appears to be a good criterion for the diagnosis of vascular inflammation, further studies are needed to define the threshold of significance as well as the clinical significance of the vascular uptake.

Comparison of FDG-PET/CT and MR with diffusion-weighted imaging for assessing peritoneal carcinomatosis from gastrointestinal malignancy

ObjectivesTo assess the accuracy of FDG-PET/CT and MR with diffusion-weighted imaging (MR-DWI) for diagnosing peritoneal carcinomatosis (PC) from gastrointestinal malignancies.MethodsThirty consecutive patients referred for staging of gastrointestinal malignancy underwent FDG-PET/CT and MR-DWI in this retrospective study. Extent of PC was characterised by dividing the peritoneal cavity into three sites in each patient: right and left supramesocolic areas and inframesocolic level (total 90 sites). Presence of PC was confirmed either by surgery (18/30) or by follow-up (12/30).ResultsPC was confirmed in 19 patients (19/30). At a total of 90 sites, 27 showed proven PC. On a patient-based analysis, sensitivity, specificity, PPV, NPV and accuracy were respectively 84%, 73%, 84%, 73% and 80% for PET/CT and 84%, 82%, 89%, 75% and 83% for MR-DWI. On a site-based analysis, overall sensitivity and specificity of PET/CT (63%, 90%) and MR-DWI (74%, 97%) were not statistically different (P = 0.27). In the supramesocolic area, MR-DWI detected more sites involved than PET/CT (7/9 vs. 4/9). The sensitivities of PET and MR were lower for subcentimetre tumour implants (42%, 50%). Interobserver agreement was very good for PET/CT and good for MR-DWI.ConclusionsFDG-PET/CT and MR-DWI showed similar high accuracy in diagnosing PC. Both techniques underestimated the real extent of PC because of decreased sensitivity for subcentimetre lesions.Key Points• FDG-PET/CT and MR-DWI showed similar high accuracy for diagnosing peritoneal carcinomatosis.• In the supramesocolic area, MR-DWI could be more sensitive than PET/CT.• Both techniques showed lower sensitivity for subcentimetre lesions.• Interobserver agreement was very good for PET/CT and good for MR-DWI.

FDG-PET/CT in patients with ANCA-associated vasculitis: case-series and literature review.

OBJECTIVES We aimed to assess the clinical value of FDG-PET/CT in patients with ANCA-associated vasculitis. MATERIALS AND METHODS We retrospectively included 16 patients with ANCA-associated vasculitis who underwent 21 FDG-PET/CT between 2009 and 2013, in 2 university hospitals from the Paris suburb area. All FDG-PET/CTs were retrospectively analyzed and compared to clinical, biological and conventional imaging data at baseline and during the follow-up. RESULTS ANCA-associated vasculitis was granulomatosis with polyangiitis (GPA, n=10), microscopic polyangiitis (MPA, n=4), and eosinophilic GPA (EGPA, n=2). PET was performed at initial presentation in 14 cases and during the follow-up in 7 cases. At baseline, PET was positive in 100% of GPA patients (8/8) and in 50% (3/6) of patients with other ANCA-vasculitis (p=0.05). FDG uptake tended to be higher in patients with GPA in comparison to patients with MPA/EGPA (median SUVmax: 5 versus 2.5; p=0.08). Sinonasal, lung, cardio-vascular and kidney involvements were all accurately identified by PET, except in one MPA patient with glomerulonephritis. As expected, skin, joint, eye and peripheral nervous system impairments were not detected by PET. No occult site was detected by PET, except in 2 salivary gland FDG uptake without clinical abnormalities. Patients with GPA exhibited a higher number of positive sites on PET (2 [1.75-2.25] versus 0.5 [0-1], p=0.006) than patients with MPA/EGPA. In pooled data including our study and the literature data of GPA patients (n=31), SUVmax was associated with Birmingham Vasculitis Activity Score (BVAS) (r=0.49; p=0.03). CONCLUSION FDG-PET/CT accurately identifies organ localizations in GPA, other than in nervous system, eye and skin, but do not bring additional benefit to the usual organ screening. The value of FDG-PET/CT in other ANCA-associated vasculitis need to be further addressed.

Tracheobronchial FDG uptake in primary amyloidosis detected by PET/CT.

Tracheobronchial amyloidosis is a rare manifestation of the disease and has never been described with FDG PET/CT. In this study, we report a case of a 70-year-old man with increasing dyspnea, a right pleural effusion, a tracheobronchial circumferential wall thickening, and a mediastinal fat infiltration on CT scan. FDG PET/CT revealed intense tracheobronchial uptake associated with mediastinal and intra-abdominal fat uptake. Bronchoscopy and mediastinoscopy with biopsies confirmed the diagnosis of primary amyloidosis and excluded malignancy. FDG PET/CT could be useful for the evaluation of tracheobronchial amyloidosis metabolic activity and follow-up.

18F-fluorodeoxyglucose positron emission tomography/computer tomography as an objective tool for assessing disease activity in Sjögren's syndrome.

OBJECTIVE This study aims to determine the value of FDG-PET/CT to assess disease activity in patients with Sjögrens syndrome (SS). METHODS Thirty-two patients with SS who underwent PET/CT were retrospectively analyzed. PET/CT activity score was measured using a 6-point scale including the 6 following items (0/1: absence or presence of an item): lymphadenopathy on CT, high-resolution CT (HRCT) evidence of interstitial lung disease (ILD), parotid glands SUVmax >3, submandibular glands SUVmax >3, lymph node uptake, ILD uptake. Combined PET/CT score was correlated to ESSDAI (EULAR Sjögrens Syndrome Disease Activity Index) score and other parameters of SS activity. RESULTS Pathological FDG uptake was observed in 75% of patients (24/32): lymph-nodes (n=19, 60%), salivary glands (n=17, 53%), lungs (n=9, 28%), and thyroid (n=2). Median ESSDAI and PET/CT activity scores were 9.5 [5-12] and 2 [0-3], respectively. PET/CT activity score correlated with ESSDAI (r=0.49, p=0.005), unlike SUVmax. Patients with a high ESSDAI score had a higher PET/CT activity score than patients with a low ESSDAI score (3 vs 1, p=0.004). PET was also correlated with gammaglobulin levels (r=0.43, p=0.02), but not with the presence of cryoglobulinemia, activated complement or beta-2 microglobulin levels. The FDG uptake in patients with lymphoma (n=4) was higher than in patients without lymphoma (SUVmax=5.4 vs. 3.2, p=0.05). CONCLUSION We described a new PET/CT activity score, which correlates to ESSDAI and could help to assess disease activity in SS patients. PET can also help in the diagnosis of lymphoma, even if inflammatory lymph nodes can be frequently observed in SS patients.

Visualization of amyloid arthropathy in light-chain systemic amyloidosis on F-18 FDG PET/CT scan.

We report a case of 63-year-old man with symmetrical joint swelling of the interphalangeal and metacarpal joints, associated with isolated hypogammaglobulinemia. Accessory glands biopsy revealed the presence of amyloidal deposits. PET/CT showed increased F-18 FDG activity in thickened soft tissues corresponding to amyloid arthropathy. Like multiple myeloma, PET/CT could be an interesting imaging in light-chain amyloidosis.

Diagnosis of synchronous isolated splenic metastasis from lung adenocarcinoma: complementary role of FDG PET/CT and diffusion-weighted MRI.

Isolated splenic metastasis is extremely rare. In this study, we report a case of a 52-year-old man referred for Pancoast Tobias Syndrome by which FDG PET/CT detected an isolated splenic metastasis. Diffusion-weighted MRI confirmed the isolated splenic lesion. A low apparent diffusion coefficient was consistent with a tumor lesion. CT-guided biopsy of both the lesions and histopathologic findings confirmed a lung adenocarcinoma with an isolated splenic metastasis. This case reveals a very rare occurrence of isolated splenic metastases in the context of lung cancer and illustrates the role of multimodality functional imaging for the early detection of uncommon metastasis.

FDG-PET in the assessment of metabolic response in patients with NSCLC treated with nivolumab: Preliminary results.

e20554Background: Immunotherapy becomes a standard treatment in non-small-cell lung carcinoma (NSCLC), locally advanced or metastatic, after prior chemotherapy. Because of systemic involvement and heterogeneity of the tumoral disease, methods of assessment are complex and the role of PET-FDG is not well established. The objective of the present study is to describe the results of FDG-PET in the evaluation of patients with NSCLC treated with checkpoint inhibitor (OPDIVO®, Nivolumab) in our academic center. Methods: A retrospective analysis of FDG-PET’s data was performed in 16 patients (performance status: 1), with NSCLC (13 adenocarcinoma, 2 squamous cell carcinoma and 1 large cell neuroendocrine carcinoma) and progression after at least one line of treatment, and treated with Nivolumab. All patients had an FDG-PET before and at 2 months (M2) of treatment. Patients showing progression at M2 had a third PET at M3 to confirm disease progression. Disease responses were assessed according to PERCIST criteria....