Role of 2-Fluoro-2-Deoxyglucose PET/Computed Tomography in Carcinoma of Unknown Primary.

FDG-PET/CT is a potentially useful imaging modality in the setting of Carcinoma of Unknown Primary (CUP) from various aspects. The central question is detection of site of primary, where most studies have documented the pooled sensitivity and specificity of FDG PET/CT in the range of 80%-85% and a tumor detection rate (after the failure of conventional imaging procedures) between 30%-37%. The heterogeneity in the (i) population studied and (ii) criteria used for labelling patient as of unknown primary, have been the prime reason for widely varying result amongst various studies. Initiating appropriate treatment strategies owing to simultaneous whole body disease staging can be regarded an added utility PET/CT, even in the case of failure of primary tumor detection. FDG-PET/CT changed the patient management in around 35% of patients (studies reporting heterogeneous results ranging from 18.2% to 60%). The futuristic approach will be to monitor molecular targeted and cystostatic therapies with FDG-PET/CT which obviously has advantages than anatomical imaging alone.

SPECT in asymptomatic diabetics with and without microalbuminuria.

OBJECTIVE: To identify coronary artery disease (CAD) in asymptomatic diabetics with the help of myocardial perfusion single photon emission computed tomography (MPS), a non-invasive imaging modality and its correlation in diabetics with or without microalbuminuria. METHODS: This study included 99 patients in the age group of 30 to 80 years who were asymptomatic but possessed one or more risk factors for CAD. These patients were divided into two groups, diabetics with and without microalbuminuria (Micral). Thirty eight patients were Micral positive and 61 were Micral negative. Ischemia was detected by MPS and compared with coronary angiographic findings in both the groups. RESULTS: Amongst the 99 diabetic patients, MPS was positive in 39 patients. Out of 39 MPS positive patients, 31(79.5%) were micral positive and 8 (20.5%) were micral negative. Out of 38 micral positive patients, 31 patients were positive on MPS and 27 had significant angiographic (CAG) findings. Those with micral positive and MPS positive had multivessel CAD by CAG. It was seen that MPS status was 91.4% sensitive, 74.1% specific and had 82.1% positive predictive values (PPV) and 87.0% negative predictive value (NPV) for detection of significant CAD. CONCLUSION: Microalbuminuria is an inexpensive screening tool and a powerful independent predictor for major cardiovascular events in patients with type 2 diabetes mellitus. MPS is a sensitive, non invasive diagnostic test for identification of CAD in asymptomatic diabetic patients.

Hot tongue on FDG PET scan in a patient of Hodgkin's lymphoma undergoing antipsychotic treatment.

Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography (F-18 FDG PET-CT) is the modality of choice for the diagnosis, staging, and restaging of many malignancies. The importance of eliminating false positives cannot be underestimated because they can dramatically alter the clinical course. We present a case of benign uptake in the tongue secondary to tardive dyskinesia in a 53-year-old woman referred for therapy response evaluation of Hodgkin's lymphoma who was concurrently receiving oral antipsychotic therapy. This case emphasizes the importance of detailed clinical history and examination when concluding definite diagnosis.