18F-FDG PET/CT 显像在直肠癌术前分期中的价值及与临床病理特征关系的研究

目的 探讨18F-氟脱氧葡萄糖（FDG）PET/CT显像在直肠癌术前肿瘤、结节、转移（TNM）分期中的价值及原发灶最大标准化摄取值（SUV_max）与临床及病理特征的相关性。 方法 回顾性分析2013年1月至2018年12月在福建省肿瘤医院术前行18F-FDG PET/CT检查且经术后病理证实为直肠癌的117例患者（男性66例、女性51例，年龄29~83岁，中位年龄57岁）的相关资料，评估18F-FDG PET/CT对直肠癌原发灶浸润深度、淋巴结转移、远处转移及临床分期的准确率。一致性检验采用Kappa检验。基于性别、年龄、病灶长径、病理类型、分化程度、淋巴血管侵犯（LVI）、周围神经侵犯（PNI）、TNM分期、临床分期进行分组，采用独立样本t检验和单因素方差分析比较组间原发灶SUV_max的差异；采用Pearson或Spearson相关分析法分析原发灶SUV_max与临床及病理特征之间的相关性。 结果 18F-FDG PET/CT对直肠癌原发灶浸润深度、淋巴结转移、远处转移、临床分期的诊断准确率分别为76.1%、81.2%、95.7%、76.9%，与病理结果的一致性为κ=0.601、0.535、0.867、0.667（均P<0.01）。不同病灶长径（t=4.982，P<0.01）、LVI（t=?2.581，P=0.011）、PNI（t=?2.873，P=0.005、N分期（t=2.792，P=0.006）、临床分期（F=3.072，P=0.031）的原发灶SUV_max的组间差异均有统计学意义；不同性别（t=0.688，P=0.493）、年龄（t=1.523，P=0.130）、病理类型（t=0.886，P=0.377）、分化程度（t=0.045，P=0.964）、T分期（F=2.323，P=0.103）、M分期（t=?1.502，P=0.136）的原发灶SUV_max的组间差异均无统计学意义。原发灶SUV_max与病灶长径、LVI、PNI、N分期、临床分期呈正相关（r=0.230~0.308，均P<0.05）。 结论 18F-FDG PET/CT对于直肠癌原发灶、淋巴结转移及远处转移均有较高的诊断准确率，是直肠癌分期的有效方法。原发灶SUV_max可部分反映肿瘤的增殖及侵袭能力。

Preoperative staging of rectal cancer with 18F-FDG PET/CT and its relationship with clinicopathological features

Objective To investigate the clinical value of 18F-fluorodeoxyglucose (FDG) PET/CT imaging in preoperative tumor, node, metastasis (TNM) staging of rectal cancer and the correlation between the maximum standardized uptake value (SUV_max) of primary lesions and clinicopathological features. Methods To evaluate the accuracy of 18F-FDG PET/CT in assessing invasion depth, lymph node metastasis, metastasis, and clinical staging before operation, a retrospective analysis was performed on data collected from 117 rectal cancer patients, including 66 males and 51 females (aged 29–83 years old, median age 57 years), who underwent 18F-FDG PET/CT examination before operation in Fujian Cancer Hospital from January 2013 to December 2018. Kappa test was used for consistency test. The patients were grouped according to gender, age, length of primary lesion, pathological type, differentiated degree, lymphovascular invasion (LVI), perineural invasion (PNI), TNM staging, and clinical staging. Independent sample t-test and one-way ANOVA were used to analyze the difference in SUV_max between groups. Pearson or Spearman correlation was used to analyze the relationship between the SUV_max of primary lesions and clinicopathological features. Results The diagnostic accuracies of 18F-FDG PET/CT on rectal cancer invasion depth, lymph node metastasis, metastasis, and clinical staging were 76.1%, 81.2%, 95.7%, and 76.9%. The consistency with pathological results was as follows (κ=0.601, 0.535, 0.867, 0.667, all P<0.01). Statistically significant differences were observed in the SUV_max of different groups of length of primary lesion (t=4.982, P<0.01), LVI (t=?2.581, P=0.011), PNI (t=?2.873, P=0.005), N staging (t=2.792, P=0.006), and clinical staging (F=3.072, P=0.031), but no statistically significant differences were observed in the SUV_max of different groups of gender (t=0.688, P=0.493), age (t=1.523, P=0.130), pathological type (t=0.886, P=0.377), differentiated degree (t=0.045, P=0.964), T staging (F=2.323, P=0.103), and M staging (t=?1.502, P=0.136). The SUV_max of the primary lesion was positively correlated with the length of the primary lesion, LVI, PNI, N staging, and clinical staging (r=0.230–0.308, all P<0.05). Conclusions 18F-FDG PET/CT has high accuracy in diagnosing rectal cancer primary lesions, lymph nodes, and metastasis and is an effective method for staging rectal cancer. The SUV_max of primary lesions can partially reflect the invasion and proliferation ability of rectal cancer.