Presurgical staging of non-small cell lung cancer: positron emission tomography, integrated positron emission tomography/CT, and software image fusion.

PURPOSES: To compare the diagnostic accuracy of positron emission tomography (PET) and integrated PET/CT and to evaluate the performance of software fusion for staging of non-small cell lung cancer (NSCLC). METHODS: Thirty-six patients (17 men and 19 women) with NSCLC underwent staging with integrated PET/CT followed by mediastinal lymph node dissection and tumor resection. Twenty-five of the 36 patients (69%) underwent separate CT studies for software fusion of images. Two blinded reviewers analyzed in consensus all PET images, and an experienced radiologist was added to assess integrated and software-fused PET/CT images. Histopathologic findings served as "gold standard" for determining the diagnostic accuracy of all modalities. RESULTS: Reviewers examining PET and integrated PET/CT classified T stage accurately in 67% (20 of 30 patients) and 97% (29 of 30 patients), respectively (p < 0.05). Overall, interpretations based on PET staged 57% (17 of 30 patients) correctly, over-staged 6 patients (20%), and under-staged 7 patients (23%). Interpretations based on integrated PET/CT correctly staged 83% (25 of 30 patients), over-staged 3 patients (10%), and under-staged 2 patients (7%). The overall staging accuracy of integrated PET/CT was significantly higher than that of PET (p < 0.05). Automatic software fusion of separately obtained PET and CT studies was successful in 68% of the patients but failed in 32%. In successful software fusion cases, the results of software fusion with regards to T stage and N stage were not different from integrated PET/CT. CONCLUSIONS: Integrated PET/CT compared with PET alone was associated with 26% points-greater overall diagnostic accuracy (p = 0.01). The software fusion method failed to provide acceptable co-registration in > 30% of the patients.

Performance of 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography and integrated PET/CT in restaged breast cancer patients.

PURPOSE: This study was conducted to compare the clinical stage derived from 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) positron emission tomography (PET) to that of integrated PET/computed tomography (CT) in restaged breast cancer patients. PROCEDURES: Fifty-eight female patients (age range 29-80 years, mean age +/-SD, 53.3 +/- 11.7 years) underwent PET/CT restaging for breast cancer. Two experienced nuclear medicine physicians interpreted PET images. A radiologist was added for reading PET/CT studies. A patient-based analysis was performed. Histopathological findings, correlative imaging studies, changes in number, size, and hypermetabolic activity of suspicious lesions and/or patient outcome served as standard of reference for determining the diagnostic accuracy of both modalities. RESULTS: PET staged 79.3% (46/58) of the patients correctly, overstaged seven (12.1%), and understaged five patients (8.6%). Integrated PET/CT staged 89.7% (52/58) of the patients correctly, overstaged four (6.9%), and understaged two patients (3.4%). The staging accuracy of PET/CT was not significantly better than that of PET alone (p = 0.059). Lesions exhibiting mild hypermetabolic activity, benign inflammatory lesions, and physiological variants largely explained incorrect PET findings. CONCLUSION: Integrated PET/CT only marginally improves the restaging accuracy over PET alone (p = 0.059) in breast cancer patients.

Pancreatic and peripancreatic diseases mimicking primary pancreatic neoplasia.

A variety of anatomic variants and pathologic conditions in and around the pancreas may simulate primary pancreatic neoplasia at routine abdominal cross-sectional imaging. An ambiguous lesion whose appearance suggests a pancreatic origin requires a broad differential diagnosis that can subsequently be narrowed on the basis of both clinical history and features at optimal computed tomography (CT) and magnetic resonance (MR) imaging. Pancreas-specific multidetector CT and MR imaging techniques with thin collimation, multiplanar and multiphasic scans, and newly introduced curved planar reformation may help avoid potential diagnostic pitfalls. These techniques can help identify and characterize a mass in multiple viewing planes, thereby helping distinguish a true pancreatic neoplasm from peripancreatic adenopathy or from a tumor of the adjacent duodenum or small bowel. They can also help determine the cause of a tumor. It is important that the radiologist be familiar with the wide spectrum of anatomic variants and disease entities that can mimic primary pancreatic neoplasia in order to initiate the appropriate lesion-specific work-up and treatment and avoid unnecessary tests or procedures, including surgery.

Comparison between 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography and positron emission tomography/computed tomography hardware fusion for staging of patients with lymphoma.

PURPOSE: 2-Deoxy-2-[18F]fluoro-D-Glucose positron emission tomography (FDG-PET) stages patients with Hodgkin's disease (HD) and Non-Hodgkin's lymphoma (NHL) with higher accuracy than computed tomography (CT). We sought to determine whether integrated (hardware) fused PET/CT imaging results in further improvements in staging accuracy. PROCEDURES: Seventy-three patients (age 51 +/- 17 years, 37 female, 36 male) with HD (n = 20) or NHL (n = 53) undergoing staging were studied with an integrated PET/CT system. Image findings were verified by clinical follow up, additional imaging and when available, histology. RESULTS: Thirty-four of 73 patients (46.5%) had evidence of disease and 39 were disease free as confirmed by clinical evaluation and follow-up for 41 +/- 22 weeks (n = 73), including biopsy (n = 26), and other imaging modalities (n = 52) when available. A discordant image interpretation between PET and PET/CT occurred in seven patients (10%). PET/CT correctly upstaged two and downstaged five patients. Overall staging was accurate in 93% with PET/CT and 84% with PET (P = 0.03). CONCLUSION: Lymphoma is staged with higher accuracy using PET/CT than PET alone.