Incremental value of integrated FDG-PET/CT in evaluating indeterminate solitary pulmonary nodule for malignancy

Mol Imaging Biol. 2010 Apr;12(2):204-9. doi: 10.1007/s11307-009-0241-0. Epub 2009 Jun 20.


Objectives: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Demography
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Lung Neoplasms / diagnostic imaging*
  • Male
  • Middle Aged
  • Positron-Emission Tomography*
  • Reproducibility of Results
  • Solitary Pulmonary Nodule / diagnostic imaging*
  • Tomography, X-Ray Computed*


  • Fluorodeoxyglucose F18