Contemporary capabilities of CT texture analysis in the diagnosis of pheochromocytoma: associations with clinical, laboratory, and pathomorphological findings

Aim. To investigate the presence of statistically significant correlations between clinical and laboratory characteristics and features of contrast-enhanced computed tomography (CT) images, as well as to assess the possibility of predicting group classification according to the PASS scale based on clinical, laboratory, and contrast-enhanced CT imaging data.

Materials and methods. A retrospective analysis was performed on preoperative four-phase contrast-enhanced CT images of 230 patients with a pathomorphologically verified diagnosis of pheochromocytoma/paraganglioma. Clinical manifestations such as the presence and duration of arterial hypertension, carbohydrate metabolism disorders, and dyslipidemia were assessed. In the first stage, comparative and correlation analyses were conducted between hormonal parameters and contrast-enhanced CT data. In the second stage, based on morphological characteristics, patients were divided into two groups: with PASS scores <4 (n=155) and PASS scores ≥4 (n=56). Logistic regression analysis was conducted to evaluate the possibility of predicting group classification based on clinical, laboratory, and contrast-enhanced CT imaging data.

Results. Pheochromocytomas/paragangliomas with isolated normetanephrine secretion type accumulate significantly more contrast agent in the arterial and venous phases of the study (p<0.001) compared to other secretion types. Correlation analysis revealed statistically significant moderate positive correlations between blood normetanephrine levels and the volume of functioning tumor tissue without necrotic areas, as well as a moderate negative correlation between blood metanephrine levels and the maximum density in the venous phase, the percentage of venous contrast enhancement, and the 90th percentile of X-ray density of the functioning tumor tissue in the venous CT phase. A statistically significant association was also found between the presence/absence of necrosis and tumor size (p<0.001), as well as between structure and tumor size (p=0.004). No statistically significant correlations were identified between laboratory parameters, imaging data, and clinical manifestations (arterial hypertension, carbohydrate metabolism disorders, dyslipidemia, and carotid artery atherosclerosis). CT image characteristics allow for prediction of group classification according to the PASS scale with an AUC of 0.647 (95% confidence interval 0.471–0.797), sensitivity of 0.923 (0.727–1.000), specificity of 0.400 (0.250–0.548), PPV of 0.333 (0.176–0.500), and NPV of 0.941 (0.800–1.000).

Conclusion. Pheochromocytomas/paragangliomas are heterogeneous pathologies with diverse clinical, hormonal, and radiological characteristics that are associated with pathomorphological findings (PASS scale).