目的探讨PET-CT以不同淋巴结短径和SUVmax为标准在结直肠癌术前N分期的准确性差异以及临床价值。方法回顾性分析2010年8月~2013年5月在第二军医大学附属长海医院行结直肠癌根治术且在术前1周内行18F-FDG PET-CT检查的结直肠癌患者80例,分别以淋巴结短径≥3、5、8、10mm,淋巴结SUVmax≥1.0、1.5、2.0、2.5为标准对结直肠癌进行术前N分期,以手术病理为诊断金标准。结果 80例结直肠癌患者,术后病理结果显示56例患者有淋巴结转移,以淋巴结短径≥3、5、8、10mm诊断结直肠癌术前N分期的准确性分别为68.8%、66.3%、51.3%、43.8%,Kappa值分别为0.528、0.473、0.274、0.171;以淋巴结SUVmax≥1.0、1.5、2.0、2.5诊断结直肠癌术前N分期的准确性分别为62.5%、63.8%、52.5%、53.8%,Kappa值分别为0.435、0.459、0.297、0.317。经卡方检验,淋巴结短径≥3mm与5mm比较差异无统计学意义(P=0.774),淋巴结短径≥3mm与8mm以及10mm比较差异有统计学意义(P=0.008,P=0.007);淋巴结SUVmax≥1.5与1.0以及2.5比较差异无统计学意义(P=1.0,P=0.096),淋巴结SUVmax≥1.5与2.0比较差异有统计学意义(P=0.022);淋巴结短径≥5mm与SUVmax≥1.5比较差异无统计学意义(P=0.727)。结论以淋巴结短径≥5mm,SUVmax≥1.5为标准诊断结直肠癌术前N分期的准确性相对较高且可操作性较好,Kappa检验与手术病理结果有较好的一致性,18F-FDG PET-CT在结直肠癌术前N分期方面的价值和诊断标准有待于进一步前瞻性研究。 Objective To investigate the accuracy and clinical value of PET-CT in the preoperative N stage of colorectal cancer with different lymph node short diameter and SUVmax as the standard. Methods A retrospective analysis of 80 patients with colorectal cancer who underwent radical mastectomy at Changhai Hospital affiliated to Second Military Medical University from August 2010 to May 2013 and who underwent 18F-FDG PET-CT within 1 week before surgery was performed. To lymph node short diameter ≥ 3, 5, 8, 10mm, lymph node SUVmax ≥ 1.0,1.5,2.0,2.5 as the standard for preoperative N staging of colorectal cancer, surgical pathology as the gold standard. Results The pathological results of 80 patients with colorectal cancer showed that 56 patients had lymph node metastasis. The accuracy of preoperative N staging of colorectal cancer with lymph node short diameter of 3, 5, 8 and 10 mm was 68.8% and 66.3% , 51.3%, 43.8% and Kappa values ​​were 0.528,0.473,0.274,0.171 respectively. The accuracy of preoperative N staging of colorectal cancer with lymph node SUVmax≥1.0,1.5,2.0,2.5 was 62.5%, 63.8%, 52.5 %, 53.8%, Kappa values ​​were 0.435,0.459,0.297,0.317. The chi-square test showed that lymph node short diameter≥3mm and 5mm had no significant difference (P = 0.774), lymph node short diameter≥3mm and 8mm and 10mm had statistical significance (P = 0.008, P = 0.007) There was no significant difference between SUVmax≥1.5 and 1.0 and 2.5 (P = 1.0, P = 0.096), there was significant difference between SUVmax≥1.5 and 2.0 (P = 0.022); lymph node short diameter≥5mm and SUVmax≥1.5 The difference was not statistically significant (P = 0.727). Conclusions The accuracy of preoperative N staging of colorectal cancer is relatively high and the operability is good with the short diameter of lymph nodes ≥5mm and SUVmax≥1.5. The Kappa test has good consistency with the surgical pathology results. The 18F-FDG The value and diagnostic criteria of PET-CT in the preoperative N staging of colorectal cancer need to be further prospectively studied.