J Korean Soc Radiol.  2021 Mar;82(2):406-416. 10.3348/jksr.2020.0065.

Association between Texture Analysis Parameters and Molecular Biologic KRAS Mutation in Non-Mucinous Rectal Cancer

• Jo SJ
• Kim SH
• Park SJ
• Lee Y
• Son JH

• KMID: 2514734
• DOI: http://doi.org/10.3348/jksr.2020.0065

Abstract

Purpose
To evaluate the association between magnetic resonance imaging (MRI)-based texture parameters and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation in patients with non-mucinous rectal cancer.
Materials and Methods
Seventy-nine patients who had pathologically confirmed rectal nonmucinous adenocarcinoma with or without KRAS-mutation and had undergone rectal MRI were divided into a training (n = 46) and validation dataset (n = 33). A texture analysis was performed on the axial T2-weighted images. The association was statistically analyzed using the Mann-Whitney U test. To extract an optimal cut-off value for the prediction of KRAS mutation, a receiver operating characteristic curve analysis was performed. The cut-off value was verified using the validation dataset.
Results
In the training dataset, skewness in the mutant group (n = 22) was significantly higher than in the wild-type group (n = 24) (0.221 ± 0.283; -0.006 ± 0.178, respectively, p = 0.003). The area under the curve of the skewness was 0.757 (95% confidence interval, 0.606 to 0.872) with a maximum accuracy of 71%, a sensitivity of 64%, and a specificity of 78%. None of the other texture parameters were associated with KRAS mutation (p > 0.05). When a cut-off value of 0.078 was applied to the validation dataset, this had an accuracy of 76%, a sensitivity of 86%, and a specificity of 68%.
Conclusion
Skewness was associated with KRAS mutation in patients with non-mucinous rectal cancer.

Keyword

Magnetic Resonance Imaging; Rectum; Neoplasm; Computer; Software; Oncogene