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Purpose: Fluoro-deoxyglucose positron emmission tomography combined with computed tomography (FDG-PET/CT) is superior to iliac bone marrow biopsy (iBMB) for detection of bone marrow involvement (BMI) in staging of Hodgkin's lymphoma (HL). The present study aims to characterize the patterns and distribution of BMI in HL as determined by FDG-PET/CT., Methods: Reports of FDG-PET/CT studies performed for staging of HL were reviewed. BMI was defined as positive iBMB and/or foci of pathological FDG uptake in the skeleton that behaved in concordance with other sites of lymphoma in studies following chemotherapy. Number of FDG uptake foci, their specific location in the skeleton and the presence of corresponding lesions in the CT component of the study, and stage according to the Ann Arbor staging system, were recorded., Results: The study included 473 patients. iBMB was performed in 336 patients. Nine patients had positive iBMB (9/336, 3%). Seventy-three patients (73/473, 15%) had FDG-PET/CT-defined BMI. The BM was the only extranodal site of HL in 52/473 patients (11 %). Forty-five patients had three or more foci of pathological skeletal FDG uptake (45/73, 62 %). Sixty-four patients (64/73, 88%) had at least one uptake focus in the pelvis or vertebrae. In 60 patients (60/73, 82%), the number of skeletal FDG uptake foci without corresponding CT lesions was equal to or higher than the number of foci with morphological abnormalities., Conclusion: FDG-PET/CT demonstrated BMI in 15% of patients with newly diagnosed HL. Diagnosis of BMI in HL by FDG-PET/CT was more sensitive than iBMB with potential upstage in 11% of patients. The most common pattern of FDG-PET/CT BMI was multifocal (at least three foci) skeletal FDG uptake, with at least one focus in the pelvis or vertebrae and no corresponding CT lesions.

Purpose: Osteomyelitis, the most serious complication of the diabetic foot, occurs in about 20 % of patients. Early diagnosis is crucial. Appropriate treatment will avoid or decrease the likelihood of amputation. The objective of this study was to assess the value of FDG PET/CT in diabetic patients with clinically suspected osteomyelitis., Methods: Enrolled in this prospective study were 39 consecutive diabetic patients (29 men and 10 women, mean age 57 years, range 28-71 years) with 46 suspected sites of foot infection. Of these 39 patients, 38 had type 2 and 1 type 1 diabetes for 4-25 years, and 28 were receiving treatment with insulin. FDG PET/CT was interpreted for the presence, intensity (SUVmax) and localization of increased FDG foci. Final diagnosis was based on histopathology and bacteriology of surgical samples, or clinical and imaging follow-up., Results: Osteomyelitis was correctly diagnosed in 18 and excluded in 21 sites. Of 20 lesions with focal bone FDG uptake, 2 were false-positive with no further evidence of osteomyelitis. Five sites of diffuse FDG uptake involving more than one bone on CT were correctly diagnosed as diabetic osteoarthropathy. FDG PET/CT had a sensitivity, specificity and accuracy of 100 %, 92 % and 95 % in a patient-based analysis and 100 %, 93 % and 96 % in a lesion-based analysis, respectively, for the diagnosis of osteomyelitis in the diabetic foot., Conclusion: FDG PET/CT was found to have high performance indices for evaluation of the diabetic foot. The PET component identified FDG-avid foci in sites of acute infection which were precisely localized on fused PET/CT images allowing correct differentiation between osteomyelitis and soft-tissue infection.

Purpose: To evaluate whether PET/low-dose CT (ldCT) using (18)F-fluorodeoxyglucose (FDG) improves characterization of indeterminate single pulmonary nodules (SPNs) in patients at high risk of lung cancer., Methods: Retrospective analysis of 307 patients who underwent FDG-PET/CT for indeterminate SPNs identified 93 (70 men, age range 46-90 years) at high risk of lung cancer (age >40 years, minimum 10 pack-year smokers). SPNs were evaluated for the presence and intensity of FDG avidity and ldCT patterns. The performance of visual and semiquantitative FDG-PET/ldCT algorithms for characterization of SPNs was compared to that of ldCT. Incongruent FDG-PET and ldCT patterns were analyzed for significance in further patient management., Results: Malignancy was diagnosed in 38% patients. FDG avidity defined 33 SPNs as true-positive (TP) and 2 as false-negative (FN) (malignant), and 41 as true-negative (TN) and 17 as false-positive (FP) (benign). For SUVmax of 2.2 (by ROC analysis) there were 27 TP, 8 FN, 48 TN and 10 FP SPNs. LdCT defined 34 TP, 1 FN, 28 TN and 30 FP lesions. Of the FP lesions on ldCT, 60% were FDG-negative. Visual PET/ldCT analysis had a sensitivity of 94%, a specificity of 70%, an accuracy of 80%, a positive predictive value (PPV) of 66%, and a negative predictive value (NPV) of 95% as compared to 77%, 83%, 81%, 73%, 86% for semiquantitative PET/ldCT and 97%, 48%, 66%, 53%, 96% for ldCT, respectively. Both PET/ldCT algorithms had statistically significantly higher specificity and accuracy than ldCT. Semiquantitative analysis showed significantly higher PPV and lower sensitivity and NPV than found with ldCT., Conclusion: A single screening procedure encompassing FDG-PET and ldCT may improve screening for lung cancer in high-risk patients. The significantly improved specificity may potentially reduce FP ldCT results and further unnecessary invasive procedures.