Correlation between ¹⁸F- FDG PET/CT with KRAS mutation in colorectal cancer

Objectives To correlate between KRAS mutation with 18F-FDG uptake in colorectal cancer (CRC).

Methods One hundred and eleven patients underwent 18F-FDG PET/CT before chemotherapy. SUVmax, SUVmean, total lesion glycolysis (TLG), and metabolic tumor volume (MTV) of the primary lesion was analyzed. PET/CT parameters were correlated with KRAS mutation and other clinical factors.

Results Eighteen patients were stage 3, and 93 patients were stage 4. KRAS mutation was positive in 49 patients. TNM stage, age, gender, T-stage, metastasis did not predict KRAS mutation. Of the PET/CT factors, higher SUVmax ((13.6±5.0 vs 11.6±4.4, p=0.025) and SUVmean (5.2±1.1 vs 4.8±1.0, p=0.046) were predictive of KRAS mutation. There was no significant correlation between MTV (54.0±40.2 vs 51.9±57.7,p=0.827) or TLG (290.6±229.8 vs 273.5±371.3, p=0.778) in KRAS mutation prediction. Using a ROC cut-off of 4.5, SUVmean had sensitivity of 73.2%, specificity of 54.3% and accuracy of 61.3% in predicting KRAS mutation.

Conclusions Our findings suggest that higher SUVmean and SUVmax were predictive for KRAS mutation in CRC.

Research Support None