title: Correlation between PET/CT parameters and KRAS expression in colorectal cancer.
abstract: OBJECTIVE
  The objective of this study was to correlate the association between mutated KRAS and wild-type colorectal cancer (CRC) by using various F-FDG PET-related parameters.
  
  
  METHODS
  One hundred twenty-one CRC patients who had undergone preoperative PET/CT were included in this study. Several PET/CT-related parameters, including SUVmax and various thresholds of metabolic tumor volume, total lesion glycolysis, and PET/CT-based tumor width, were measured. Tumor- and PET/CT-related parameters were correlated with genomic expression between KRAS mutant and wild-type groups, using a Mann-Whitney U test and logistic regression analysis.
  
  
  RESULTS
  Colorectal cancer tumors with a mutated KRAS exhibited higher SUVmax and an increased accumulation of FDG among several threshold methods. Multivariate analysis showed that SUVmax and using a 40% threshold level for maximal uptake of TW (TW40%) were the 2 predictors of KRAS mutations. The odds ratio was 1.23 for SUVmax (P = 0.02; 95% confidence interval, 1.01-1.52) and 1.15 for TW40% (P = 0.02; 95% confidence interval, 1.02-1.30). The accuracy of SUVmax for predicting mutated KRAS was higher in patients with colon or sigmoid colon cancers, whereas it was TW40% in those with rectal cancers.
  
  
  CONCLUSIONS
  SUVmax and TW40% were associated in CRC with KRAS mutations. PET/CT parameters can supplement genomic analysis to determine KRAS expression in CRC.
authors: From the *Department of Radiation Oncology, China Medical University Hospital; and †Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University, Taichung; ‡School of Medicine, Taipei Medical University, Taipei; and §Departments of Surgery and ∥Department of Nuclear Medicine and PET Center, China Medical University Hospital; ¶Department of Biomedical Imaging and Radiological Science, China Medical University; and **Cancer Center, China Medical University Hospital, Taichung, Taiwan.
authors: Shang-Wen
authors: SW
authors: Chen
authors: Hua-Che
authors: HC
authors: Chiang
authors: William Tzu-Liang
authors: WT
authors: Chen
authors: Te-Chun
authors: TC
authors: Hsieh
authors: Kuo-Yang
authors: KY
authors: Yen
authors: Shu-Fen
authors: SF
authors: Chiang
authors: Chia-Hung
authors: CH
authors: Kao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics / Q000378:metabolism; D003627:Data Interpretation, Statistical; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009154:Mutation; D049268:Positron-Emission Tomography; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras); D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins