Tuesday, January 23, 2007

Low uptake on PET & malignancy

Benign and malignant pulmonary lesions usually are differentiated by 18F-FDG PET with a semiquantitative 18F-FDG standardized uptake value (SUV) of 2.5. However, the frequency of malignancies with an SUV of less than 2.5 is significant, and pulmonary nodules with low 18F-FDG uptake often present diagnostic challenges. These results suggested that for solid pulmonary lesions with low 18F-FDG uptake, semiquantitative approaches do not improve the accuracy of 18F-FDG PET over that obtained with visual analysis. Pulmonary lesions with visually absent uptake indicate that the probability of malignancies is very low. In contrast, the probability of malignancy in any visually evident lesion is about 60%.
Reference-Accuracy of PET for Diagnosis of Solid Pulmonary Lesions with 18F-FDG Uptake Below the Standardized Uptake Value of 2.5
Journal of Nuclear Medicine Vol. 47 No. 3 426-431

2 comments:

Anonymous said...

In contrast, the probability of malignancy in any visually evident lesion is about 60%

I practice in a locale with coccidiomycosis. There are great numbers of benign lung nodules with mild to moderate FDG accumulation. In fact, I have such a lung nodule myself. Our positive predictive value is nothing like 60%. Maybe 30 or 40% would be more like it.

Anonymous said...

I had a pet scan that stated mild uptake, but yet lesion has a SUV of 4.9. Even with an SUV of 4.9 can this be inflamation or scar tissue?

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