lutetium-orthosilicate and Lung-Neoplasms

Our aim was to compare the maximum standardized uptake value (SUVmax) between breath-hold (BH) PET/CT and free-breathing (FB) PET/CT.. The features of phantom data were analyzed, after which a clinical study was performed. A total of 108 consecutive patients with lung cancer were examined using lutetium oxyorthosilicate (LSO)-based PET/CT. The patients were instructed to breathe freely during FB PET/CT. In BH PET/CT, the patients were instructed to hold their breath in the maximal inspiration position during the scout scan, for 10 s of the CT scan, and for as long as possible during the PET scan. BH time was recorded using a respiratory monitoring device. The %BH-index was defined as the percentage difference between SUVmax of FB PET and that of BH PET. Statistical analyses were performed using the following factors: %BH-index, age, body mass index, 18F-FDG dosage, blood glucose, BH time, lesion size, and location.. The highest %BH-index was 223.2. %BH-index in the lower lung area was significantly higher than that in the upper lung area (51.8 +/- 49.5 vs. 16.9 +/- 25.6, respectively). Lesion volume and maximum diameter in the high-%BH-index group were significantly lower than those in the low-%BH-index group, with the use of a %BH-index cutoff value of 37.l.. SUVmax of FB PET should not be taken as accurate, especially in the lower lung area and for small pulmonary lesions. BH PET/CT is expected to enable precise measurement of SUVmax and is thus recommended as part of the standard protocol for lung cancer.

Topics: Aged; Artifacts; Female; Fluorodeoxyglucose F18; Humans; Inhalation; Lung Neoplasms; Lutetium; Male; Middle Aged; Phantoms, Imaging; Positron-Emission Tomography; Radiopharmaceuticals; Silicates; Subtraction Technique; Tomography, X-Ray Computed

To determine the concordance of a prototype dual head coincidence camera (LSO-PS) and full ring PET (BGO-PET) using (18)F-fluorodeoxyglucose (FDG) in the evaluation of pulmonary nodules (PNs).. Patients referred for evaluation of < or =3 PNs (< or =3 cm diameter) were prospectively studied on the same day with both BGO-PET and LSO-PS. Imaging was performed at 60 and 120 min after injection of 370MBq FDG, respectively. Images were independently interpreted by four observers with each observer blinded to the other modality for the same patient. Lesions were scored in terms of relative intensity versus background. Non-attenuation corrected (nonAC) BGO-PET was used as the reference test.. Forty-seven patients with 54 PNs (mean diameter 1.7 cm, S.D. 0.7) were included. Twelve nodules were in the < or =1.0 cm - 27 in the 1.1-2.0 cm - and 15 in the 2.1-3.0 cm range. Interobserver agreement was similar for both FDG imaging modalities. Using a sensitive assessment strategy with LSO-PS (> or = faint intensity deemed positive), there was a 97% (38/39, 95%CI 87-100%) concordance with BGO-PET and one false positive case with LSO-PS. Conservative reading (moderate or intense intensity deemed positive) resulted in a 92% (36/39, 95%CI 80-97%) concordance with BGO-PET, without false positives. The only lesion missed by LSO-PS using both assessment strategies involved a nodule 1.5 cm diameter that demonstrated moderate increased FDG uptake on BGO-PET.. Depending on the test positivity criteria, LSO-PS demonstrates a high concordance (92-97%) with nonAC BGO-PET for the characterization of pulmonary nodules.

Topics: Aged; Algorithms; Female; Gamma Cameras; Humans; Image Processing, Computer-Assisted; Lung Neoplasms; Lutetium; Male; Positron-Emission Tomography; Prospective Studies; Silicates; Solitary Pulmonary Nodule; Statistics, Nonparametric