Preliminary study on the correlation between grading and histology of solitary pulmonary nodules and contrast enhancement and [¹⁸F]fluorodeoxyglucose standardised uptake value after evaluation by dynamic multiphase CT and PET/CT

Abstract

AimTo evaluate whether the histology and grading of solitary pulmonary nodules (SPNs) correlated with the results of dynamic multiphase multidetector CT (MDCT) and the [18F]fluorodeoxyglucose standardised uptake value (SUV) in 30 patients.MethodsChest x-rays of 270 patients with incidentally detected SPNs were retrospectively evaluated. Thirty patients with histologically proven SPNs were enrolled. On MDCT and positron emission tomography (PET)/CT images, two experts measured the density of nodules in all perfusion phases and the SUV. Net enhancement (NE) was calculated by subtracting peak pre-contrast density from peak post-contrast density. The Pearson test was used to correlate nodule NE, SUV, grading, histology and diameter.ResultsOf the 30 malignant SPNs, six were classified as G1 (median NE, 31.5 Hounsfield units (HU); median SUV, 4.8 units), 15 were classified as G2 (median NE, 49 HU; median SUV, 6 units), and nine were classified as G3 (median NE, 32 HU; median SUV, 4.5 units). A highly negative correlation was found in G3 SPNs between NE and the corresponding diameters (r=−0.834; p=0.00524). NE increased with the increase in diameter (r=0.982; p=0.284). SUV increased as the SPN diameter increased (r=0.789; p=0.421). NE and SUV were higher in G2 than G1 SPNs, and lower in G2 than G3 SPNs (r=0.97; p=0.137).ConclusionsThe significant correlation in dedifferentiated (G3) SPNs between NE and diameter (r=−0.834; p=0.00524) supports the theory that stroma and neoangiogenesis are fundamental in SPN growth. The highly negative correlation between NE and diameter demonstrates a net decrease in perfusion despite an increase in dimension. The multidisciplinary approach used herein may result in a more precise prognosis and consequently a better therapeutic outcome, particularly in patients with undifferentiated lung cancer.

Using the CT features to differentiate invasive pulmonary adenocarcinoma from pre-invasive lesion appearing as pure or mixed ground-glass nodules

“…24 Similar results have also been reported between standardized uptake value and microvessel density and histological grading. 25 Therefore, CT and positron emission tomography (PET)/CT may play an important role in evaluating the neovascularization of pulmonary nodules. However, a comparative study on the value of routine CT scan with dynamic CT or PET-CT in evaluating the neovascularization of pulmonary nodules is still lacking.…”

Diagnostic Accuracy of Contrast-Enhanced Computed Tomography and Positron Emission Tomography With 18-FDG in Identifying Malignant Solitary Pulmonary Nodules

“… 29 , 30 Interestingly, an increased glucose metabolism measured as SUV might have a prognostic value in terms of tumor progression, recurrence, and hazard of death. 30 – 32 However, Cappabianca et al 33 reported no correlation between SUV and grading of malignant SPN.…”

Dynamic contrast-enhanced MRI versus 18F-FDG PET/CT: Which is better in differentiation between malignant and benign solitary pulmonary nodules?

“…As the EES pressure increases, the contrast media passes back into the vessel rapidly. Normally, a higher K ep indicates a higher cell density and vascular permeability of malignant tissue (25). The malignant SPN tissue has a higher microvascular density due to tumor angiogenesis and results in much more permeable capillaries (17,26).…”