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.
Clin Nucl Med. 2014 Aug;39(8):685-9. doi: 10.1097/RLU.0000000000000481.
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.
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.
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.
SUVmax and TW40% were associated in CRC with KRAS mutations. PET/CT parameters can supplement genomic analysis to determine KRAS expression in CRC.
本研究旨在通过使用各种 F-FDG PET 相关参数来关联突变型 KRAS 和野生型结直肠癌（CRC）之间的关系。
本研究纳入了 121 例接受术前 PET/CT 的 CRC 患者。测量了几种 PET/CT 相关参数，包括 SUVmax 和代谢肿瘤体积、总肿瘤糖酵解、基于 PET/CT 的肿瘤宽度的各种阈值。使用 Mann-Whitney U 检验和逻辑回归分析，将肿瘤和 PET/CT 相关参数与 KRAS 突变和野生型组之间的基因表达进行相关性分析。
KRAS 突变的结直肠肿瘤表现出更高的 SUVmax 和 FDG 摄取增加，在几种阈值方法中。多变量分析显示，SUVmax 和使用 40%的最大摄取阈值 TW（TW40%）是 KRAS 突变的 2 个预测因子。SUVmax 的优势比为 1.23（P = 0.02；95%置信区间，1.01-1.52），TW40%为 1.15（P = 0.02；95%置信区间，1.02-1.30）。SUVmax 预测 KRAS 突变的准确性在结肠癌或乙状结肠癌患者中较高，而在直肠癌患者中则为 TW40%。
SUVmax 和 TW40% 与 CRC 中 KRAS 突变有关。PET/CT 参数可以补充基因组分析，以确定 CRC 中的 KRAS 表达。
