专利蓝和放射物联合示踪检测胃癌前哨淋巴结及其临床意义

Clinical significance of sentinel lymph node detection by combining the dye-directed and radioguided methods in gastric cancer

目的探讨胃癌中前哨淋巴结(SLN)概念的适用性,评估前哨淋巴结活检预测胃癌区域淋巴结转移状态的价值及其指导胃癌淋巴结清扫范围的临床意义。方法26例胃癌患者,术前经胃镜于病灶周围黏膜下注入99mTc标记的硫胶体,术中于病灶周围浆膜下直接注入专利蓝,将γ探测仪检测放射活性高出背景组织10倍以上或(和)蓝染的淋巴结视为胃癌前哨淋巴结,行常规病理检查和细胞角蛋白免疫组化染色,分别计算前哨淋巴结诊断胃癌淋巴结转移状态的准确性、敏感性、阴性预测值和假阴性率,并根据前哨淋巴结活检结果决定胃癌的手术方式。结果胃癌前哨淋巴结的检出成功率为96%(25/26),每例检出1～6个,平均3.2个/例。胃癌前哨淋巴结仅限于N1分布的占50%(13/26),仅限于N2或N3分布的占12%(3/26)。SLN诊断胃癌周围淋巴结转移状态的准确性为96%,敏感性为94%,阴性预测值为7/8,假阴性率为6%。对前哨淋巴结的彻底病理检查使2/7胃癌病例的淋巴结病理分期得到上调。结论前哨淋巴结概念适合于胃癌;联合示踪法胃癌前哨淋巴结活检可准确预测胃癌周围淋巴结的转移状态,并可能用于指导胃癌的淋巴结清扫范围。

Objective To investigate the feasibility and accuracy of detection of sentinel lymph nodes (SLN) with combining the dye-directed and radioguided methods in gastric cancer and assess its potential role in determining the rational extent of lymphadenectomy in gastric cancer surgery. Methods^Twenty-six patients of gastric cancer diagnosed as T_1-T_3 were enrolled in this study. Endoscopic injection submucosally of ~99m Tc labeled sulfur colloid solution was performed around the primary tumor 2-4 h before operation. Immediately after laparotomy, patent blue violet was injected into subserosal layer adjacent to the tumor. SLNs were defined as blue stained nodes or (and) those containing 10 times more radioactivity than surrounding tissue with a gamma probe. Standard radical gastrectomy with lymphadenectomy (D_2 or D_3) was performed in most of the patients, however, limited surgery was performed in early gastric cancer (EGC) when a rapid frozen examination indicated negative SLNs. All resected nodes were examined postoperatively by routine HE stain and those negative SLNs were examined with further cytokeratin immunohistochemistical staining. The diagnostic accuracy, sensitivity, negative predictive value and false-negative rate of regional lymph node status on the basis of SLN status were calculated respectively. Results SLNs were dectected in 25 of 26 patients with a successful detection rate of 96%. The number of SLNs ranged from 1 to 6, with a mean value of 3.2 per case. The SLNs of gastric cancer were only found in N_1 area in 50% of the cases, and only in N_2 or N_3 in 12%. The incidence of metastasis was significantly higher in SLNs than in non-SLNs (35% vs 7%). The diagnostic accuracy, sensitivity, negative predictive value and false-negative rate were 96%, 94%, 7/8 and 6% respectively. Complete analysis of SLN upstaged 2/7 of patients of gastric cancer. Conclusions The SLN concept is validated in gastric cancer. Combined-agent SLN mapping is an accurate diagnostic procedure for detecting lymph node metastasis in patients with gastric cancer and may indicate rational extent of lymphadenectomy for gastric cancer.