title: Time sensitivity factor of single pulmonary nodule: a new cancer characteristic metabolic parameter by (18) F-FDG PET.
abstract: OBJECTIVE
  To calculate the time sensitivity factor (S) for discriminating the solitary pulmonary nodule (SPN) by FDG PET at different time points.
  
  
  METHODS
  The multiple time-point FDG PET images from 41 patients for evaluating SPN seen on chest X-ray or CT were prospectively analyzed to calculate and evaluate S against the gold standard of tissue histology (n = 38) or long term clinicoradiographic follow-up (n = 3). The maximal standardized uptake values (SUV) at the 3 hourly time points were measured. The S was calculated using S = d{ln⁡(SUV)}/d{ln⁡(t)} at 3 different time intervals. ROC analysis of the S parameters was performed to evaluate the optimal cut-off value and their accuracy in classifying the SPN.
  
  
  RESULTS
  The SUV in malignant SPN was higher than the corresponding value in benign lesions at all 3 hourly time points (P < 0.003). The S parameters using 3 different time intervals all significantly separated the two groups (P < 0.0005) with an optimal cut-off point near the theoretical value of zero with a high sensitivity of 100% and specificity of 86%. CONCLUSION. The S can be calculated for SPNs using multiple time-point FDG PET, providing a tumor characteristic metabolic parameter with high discrimination power using a simple positive value representing malignancy.
authors: Department of Chest Surgery, Changhua Christian Hospital, Changhua, Taiwan.
authors: Ching-Yuan
authors: CY
authors: Cheng
authors: Department of Radiology, Changhua Christian Hospital, Changhua, Taiwan.
authors: Kwo-Whei
authors: KW
authors: Lee
authors: Departments of Nuclear Medicine and Anesthesiology, Chi-Mei General Hospital, Tainan, Taiwan.
authors: Chiang-Hsuan
authors: CH
authors: Lee
authors: Department of Radiology, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors: Yeu-Sheng
authors: YS
authors: Tyan
authors: Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan.
authors: Cheng-Yi
authors: CY
authors: Cheng
authors: Departments of Nuclear Medicine and Anesthesiology, Chi-Mei General Hospital, Tainan, Taiwan.
authors: Jhi-Joung
authors: JJ
authors: Wang
authors: Department of Nuclear Medicine, Changhua Christian Hospital, 135 Nan-Hsiao Street, Changhua 50006, Taiwan.
authors: Chao-Wei
authors: CW
authors: Yang
authors: Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan ; Department of Nuclear Medicine, Changhua Christian Hospital, 135 Nan-Hsiao Street, Changhua 50006, Taiwan.
authors: Wen-Sheng
authors: WS
authors: Huang
authors: Department of Nuclear Medicine, Oakland University William Beaumont Hospital, 3601 W. Thirteen Mile Road, Royal Oak, MI 48073-6769, USA.
authors: Ching-Yee
authors: CY
authors: Oliver Wong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012372:ROC Curve; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000378:metabolism*; D013997:Time Factors
chemical_list: D019788:Fluorodeoxyglucose F18