Incremental value of integrated FDG-PET/CT in evaluating indeterminate solitary pulmonary nodule for malignancy.
OBJECTIVE
The objective of this study was to evaluate the increased diagnostic benefit of integrated positron emission tomography/computed tomography (PET/CT) interpretation in evaluating solitary pulmonary nodules for malignancy.


METHODS
One hundred seventeen patients (67 men and 50 women; mean age +/- SD, 61.7 +/- 13.6 years, range, 31-86 years) with indeterminate solitary pulmonary nodules and no previous history of malignancy were analyzed. PET/CT was performed with an integrated PET/CT scanner (Siemens Biograph BGO duo) 1 h after an intravenous injection of 370 MBq (10 mCi) (18)F-fluorodeoxyglucose. Patients fasted for 6 h before imaging. PET was interpreted alone or combined with CT and was graded according to a five-point scale. A malignant diagnosis was based on histological findings or a clinical and radiological follow-up after at least 24 months. The diagnostic performances of PET alone and integrated PET/CT interpretation were evaluated using discriminant analysis.


RESULTS
PET alone correctly classified 85% of nodules and integrated PET/CT interpretation increased the correct classification to 89%, with similar sensitivity and specificity of 88% and 89%, respectively. False-positive PET results mainly resulted from granulomatous disorders. Four (50%) of the eight cases deemed indeterminate on PET alone were resolved with combined PET/CT interpretation.


CONCLUSIONS
Although the benefit attributable to the CT component was limited when integrated PET/CT was used, PET and CT acted synergistically to significantly increase the diagnostic veracity for PET-indeterminate nodules.
Chang
Chih-Yung
CY
Department of Nuclear Medicine, Tri-Service General Hospital, National Defense Medical Center, 325 Section 2 Cheng-Kung Road, Taipei, Taiwan.
Tzao
Ching
C
Lee
Shih-Chun
SC
Cheng
Cheng-Yi
CY
Liu
Chang-Hsien
CH
Huang
Wen-Sheng
WS
Ku
Chih-Hung
CH
Lee
Jong-Kang
JK
Oliver Wong
Ching-Yee
CY
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003710:Demography; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D015203:Reproducibility of Results; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
D019788:Fluorodeoxyglucose F18