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OBJECTIVE: To determine the accuracy of visual analysis and the retention index (RI) with dual-time point 18F-FDG PET/CT for the characterization of indeterminate pulmonary nodules (IPN) with low FDG uptake. MATERIALS AND METHODS: A retrospective analysis was performed on 43 patients (28 men, 64 ± 11 years old, range 36-83 years) referred for IPN characterization with 18F-FDG-PET/CT and maximum standard uptake value ≤ 2.5 at 60 minutes post-injection (SUVmax1). Nodules were analyzed by size, visual score for FDG uptake on standard (OSEM 2,8) and high definition (HD) reconstructions, SUVmax1, SUVmax at 180 minutes post-injection (SUVmax2), and RI was calculated. The definitive diagnosis was based on histopathological confirmation (n = 28) or ≥ 2 years of follow-up. RESULTS: Twenty-four (56%) nodules were malignant. RI ≥ 10% on standard reconstruction detected 18 nodules that would have been considered negative using the standard SUVmax ≥ 2.5 criterion for malignancy. RI ≥ 10% had a sensitivity, specificity, PPV, NPV and accuracy of 75, 73.7, 78.3, 70, and 74.4%, respectively, while for FDG uptake > liver on HD these were 79.1, 63.2, 73.1, 70.6, and 72.1%, respectively. SUVmax1 ≥ 2, SUVmax2 > 2.5 and FDG uptake > liver on standard reconstruction had a PPV of 100%. FDG uptake > mediastinum on HD had a NPV of 100%. CONCLUSIONS: RI ≥ 10% was the most accurate criterion for malignancy, followed by FDG uptake > liver on HD reconstruction. On standard reconstruction, SUVmax1 ≥2 was highly predictive of malignancy, as well as SUVmax2 > 2.5 and FDG uptake > liver. FDG uptake < mediastinum on HD was highly predictive of benign nodules.
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OBJECTIVE: Lung cancer (LC) is the leading cause of death from cancer worldwide. More than 27,000 LCs are diagnosed annually in Spain, and most are unresectable. Early detection and treatment reduce LC mortality. This study describes surgical outcomes in a longstanding LC screening cohort in Spain. METHODS: We conducted a retrospective study of surgical outcomes in a LC screening (LCS) program using low dose computed tomography (LDCT) since the year 2000. A descriptive analysis of clinical and radiological parameters, presence or absence of a preoperative diagnosis, pathological staging, morbidity, mortality, and survival was performed. RESULTS: Ninety-seven (2.5%) LC were diagnosed in 3825 screened. Twenty individuals with LC had no surgery due to advanced stage or small cell histology. Eighty-seven surgical procedures were carried out for suspected or biopsy proven LC, detected by LDCT. Most operated patients were male (57[85%]) aged 64±9.1 years. Nine patients underwent a second operation for a metachronous primary lung cancer. Mean tumor size was 15.2±7.6mm. Eight nodules were benign (9.2%). Lobectomy was performed in 56 cases (83.6%). Adenocarcinoma (n=39; 58.2%) was the most frequent histological type followed by squamous cell carcinoma (n=17; 25.4%). Fifty-nine (88%) tumors were in Stage I. Thirteen patients (15.4%) had 16 complications. The estimated survival rates at 5 and 10 years for stage I were 93% (95% CI: 79%-98%) and 83% (95% CI: 65%-92%), respectively. CONCLUSION: Lung cancer screening was associated with excellent surgical outcomes with 5 and 10-year survival rates exceeding 90 and 80%, respectively.