How dual-energy CT can help treat patients with pure ground-glass nodules

Dual-energy CT (DECT) shows potential as an effective tool for treating patients with pure ground-glass nodules (pGGNs), according to a new study in the American Journal of Roentgenology.

Lead author Yang Yang, of the Affiliated Zhongshan Hospital of Dalian University in China, and colleagues found that enhanced dual-source DECT can help radiologists differentiate invasive pulmonary adenocarcinomas (IPAs) from preinvasive lesions when patients present with pGGNs. The team studied enhanced dual-source DECT data from 39 patients with a total of 53 pGGNs who underwent surgical lung re-section from January 2017 to August 2018. The pGGNs were also analyzed using unenhanced images.

Overall, the authors noted “significant differences” between IPAs and preinvasive lesions in two key areas: lesion size and unenhanced CT attenuation value.

“For lobulation, spiculation, air bronchogram, bubble lucency and pleura retraction, no significant differences were observed between the two groups,” Yang and colleagues wrote.

The team ultimately concluded that a lesion’s normalized iodine concentration (NIC) played a key role in differentiating the patients’ pGGN. If the modified NIC value was more than 0.29, it is “a very specific discriminator of IPAs from preinvasive lesions.”

“It is important to distinguish IPAs from preinvasive lesions for proper management,” the authors wrote. “However, few accurate and reliable markers can achieve this goal. Fortunately, our results showed that the modified NIC is a significant factor in differentiating IPAs appearing as pGGNs from preinvasive lesions.”

This is a key finding, Yang et al. concluded, “because it may provide guidance to the clinical decision making for those lesions on CT.”