Analysis of CT features and quantitative texture analysis in patients with thymic tumors: correlation with grading...

To evaluate potential relationship between qualitative CT features, quantitative texture analysis (QTA), histology, WHO staging, Masaoka classification and myasthenic syndrome in patients with thymic tumors.

Sixteen patients affected by histologically proven thymic tumors were retrospectively included in the study population. Clinical information, with special regard to myasthenic syndrome and serological positivity of anti-AchR antibodies, were recorded. Qualitative CT evaluation included the following parameters: (a) location; (b) tumor edges; (c) necrosis; (d) pleural effusion; (e) metastases; (f) chest wall infiltration; (g) tumor margins. QTA included evaluation of "Mean" (M), "Standard Deviation" (SD), "Kurtosis" (K), "Skewness" (S), "Entropy" (E), "Shape from Texture" (TX_sigma) and "average of positive pixels" (MPP). Pearson-Rho test was used to evaluate the relationship of continuous non-dichotomic parameters, whereas Mann-Whitney test was used for dichotomic parameters.

Histological evaluation demonstrated thymoma in 12 cases and thymic carcinoma in 4 cases. Tumor necrosis was significantly correlated with QTA Mean (p = 0.0253), MPP (p = 0.0417), S (p = 0.0488) and K (p = 0.0178). WHO staging was correlated with Mean (p = 0.0193), SD (p = 0.0191) and MPP (p = 0.0195). Masaoka classification was correlated with Mean (p = 0.0322), MPP (p = 0.0315), skewness (p = 0.0433) and Kurtosis (p = 0.0083). Myasthenic syndrome was significantly associated with Mean (p = 0.0211) and MPP (p = 0.0261), whereas tumor size was correlated with Mean (p = 0.0241), entropy (p = 0.0177), MPP (p = 0.0468), skewness (p = 0.009) and Kurtosis (p = 0.006).

Our study demonstrates significant relationship between radiomics parameters, histology, grading and clinical manifestations of thymic tumors.