核素法定位临床检查无淋巴结转移喉癌及下咽癌前哨淋巴结的研究

目的 分析核素法中放射性活性淋巴结的转移特点,探讨临床检查未发现转移淋巴结(clinically NO,cNO)喉癌及下咽癌前哨淋巴结(sentinel lymph node,SLN)的定位方法.方法 对45例具有高隐匿性转移的cNO喉癌和下咽癌患者,在局麻下距肿瘤边缘约1～2 mm处分3、4个等距离点注射99m锝-硫化胶体(99mTc-labeled sulfur colloid 99mTc-SC),2 h后行核素扫描探测颈部高核素浓集的淋巴结.10～12 h后开始手术,术中用手提式γ探测仪探测腮腺咬肌区的放射活性值作为本底背景值.翻开颈阔肌皮瓣探测术野,将放射活性计数值高于本底背景值的所有淋巴结定义为SLN.切取SIN并行常规、连续切片病理检查和免疫组化法检查微小转移灶.所有患者SLN切除后即行择区性颈淋巴清扫术,并按肿瘤不同部位和T分级行原发灶切除术.结果 有4例未能检出SLN;其余41例共51侧颈部检出SLN,13例共15侧颈部SLN中发现肿瘤转移,1例假阴性.以颈清扫标本病理诊断结果为金标准,定位活检成功率为92.7%,灵敏度为93.7%,假阴性率为6.3%,准确度为98.0%.在SLN有转移的15侧颈部中,有11侧(73.3%)转移发生在放射性计数值最高的SLN,转移阳性的淋巴结均在每侧放射活性计数值最高的前3枚淋巴结中.结论 核素法定位喉癌下咽癌SLN有临床应用前景,取放射性计数值最高的前3枚SLN能较准确地判断颈淋巴结有无转移.

Localization of sentinel lymph node with radionuelide in clinincally NO laryngeal and hypopharyngeal cancers

Objective To analyze the characteristic of the radioactive lymph node with metastatic disease and to explore the method of the localization of sentinel lymph node(SLN) with radionuclide in NO clinincally laryngeal and hypopharyngeal cancer. Methods Fourty-five patients with T1-T4 and clinically NO laryngeal and hypopharyngeal cancer were recruited. For each patient a peritumoral submucosal injection of 99mTc-labeled sulfur colloid (99mTc-SC) was performed and lymph node mapping was performed by lymphoscintigraphy two hours afterward. The SLN was localized by a handheld gamma probe intraoperatively 10- 12 hours after the injection. All hot lymph nodes accumulating activity were harvested and initially termed sentinel nodes. Selective neck dissections were performed for all patients. The specimen of SLN was sent to the pathologist for the following analysis: formal paraffin embedded section, consecutive section and immunohistochemistry assay. The results was compared to the remaining lymphadenectomy specimen. Resection of the primary tumour depended on the location and the T classification. Results SLNs were identified in 41 of 45 patients with 51 necks, SLNs had occult metastases in 13 cases, 15 necks with SLN-positive of these 13 cases, there was one false negative case, they were found in non-SLNs of neck specimens. Each neck side was considered a single case. SLN identification rate was 92.7%, sensitivity was 93.7%, false-negativeratc was 6.3%, and accuracy was 98.0%. In 11 (73.3%) of these SLN-positive necks, the SLN with the highest counts contained tumor; harvesting the first-three nodes with the highest radioactive counts, which could all patients with occult metastatic disease. Conclusions Excision of the first-three SLNs with the highest radioactive counts can accurately judge the presence or absence of the cervical lymph nodes metastases in patients with the clinically NO laryngeal and hypopharyngeal cancer.