AUTHOR=Cao Lixiu , Zhang Libo , Xu Wengui 

TITLE=Small hyperattenuating adrenal nodules in patients with lung cancer: Differentiation of metastases from adenomas on biphasic contrast-enhanced computed tomography

JOURNAL=Frontiers in Oncology

VOLUME=Volume 13 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2023.1091102

DOI=10.3389/fonc.2023.1091102

ISSN=2234-943X

ABSTRACT=Objective
To evaluate the value of biphasic enhanced CT (CECT) in the differential diagnosis of metastasis and lipoid poor adenoma (LPA) in lung cancer patients with unilateral small hyperattenuating adrenal nodule.
Materials and Methods
This retrospective study included 241 lung cancer patients with unilateral small hyperattenuating adrenal nodule (metastases, 123; LPAs, 118). All patients underwent plain chest or abdominal CT scan and  biphasic CECT scan, including arterial and venous phase. Qualitative and quantitative clinical and radiological characteristics of the two groups were compared using univariate analysis. An original diagnostic model was developed using multivariable logistic regression, and then according to odd ratio (OR) of the risk factors of metastases, a diagnostic scoring model was developed. The areas under the receiver operating characteristic curves (AUCs) of the two diagnostic model were compared by DeLong test.
Results
Compared with LAPs, metastases were older and showed more frequently irregular in shape and cystic degeneration/necrosis (all p<0.05). Enhancement ratio on venous (ERV) and arterial(ERA) phase of LAPs were noticeably higher than that of metastases while attenuation values on unenhanced phase (CTU) of LPAs was noticeably lower than that of metastases(all p<0.05). Compared to LAPs, the proportion of male and III/ IV clinical stage and small cell lung cancer(SCLL) were significantly higher for metastases(all p<0.05). As for peak enhancement phase, LPAs showed relatively faster wash-in and earlier wash-out enhancement pattern than metastases (p <0.001). Multivariate analysis revealed age≥59.5years (OR: 2.269; p=0.04), male(OR: 3.511; p=0.002), CTU≥27.5HU (OR: 6.968; p<0.001), cystic degeneration/necrosis (OR: 3.076; p=0.031), ERV≤1.44, (OR: 4.835; p <0.001), venous phase or  equally enhanced(OR: 16.907; p <0.001 or OR: 14.036;p <0.001), and clinical stage II or III or IV(OR: 3.550; p =0.208 or OR: 17.535; p =0.002 or OR: 20.241; p =0.001) were hazard factors for diagnosis of metastases. AUCs of the original diagnostic model and the diagnostic scoring model for metastases were 0.919 and 0.914, respectively; There was no statistical significance of AUC between the two diagnostic model(p=0.644).
Conclusions
Biphasic CECT performed well diagnostic ability in differentiating metastases from LAPs. The diagnostic scoring model is easy to popularize due to simplicity and convenience.