甲状腺乳头状癌前哨淋巴结活检的临床意义

目的 探讨甲状腺乳头状癌颈部前哨淋巴结(SLN)活检的准确性及可行性.方法 前瞻性分析23例临床淋巴结阴性(cNO)的甲状腺乳头状癌患者,术前2～5 h在超声引导下瘤体内注入99Tcm-右旋糖酐(99Tcm-DX)74 MBq,术中在肿瘤周围注入亚甲蓝0.2～0.4 ml.采用核素法(淋巴结闪烁显像法+γ探针法)和染料法定位SLN,并行术中冰冻病理检查,与术后颈清扫标本常规病理进行对照.结果 23例甲状腺乳头状癌患者均检测出SLN,检出率达100%(23/23).其中染料法和核素法的检出率分别为87.0%和100%.23例患者中,SLN冰冻阳性12例.1例术中冰冻检测SLN未发现转移癌而术后常规病理发现转移;1例SLN冰冻及病理均未发现转移,但颈清扫标本中非SLN(Ⅵ区)有转移.有21例患者的SLN活检结果与术后颈部淋巴结常规病理结果相符,准确度为91.3%(21/23),阳性预测值为100%(12/12),阴性预测值为81.8%(9/11).结论 SLN活检对预测cNO甲状腺乳头状癌的颈部淋巴结转移和指导临床治疗有重要的意义.

Sentinel lymph node biopsy in papillary thyroid cancer

Objective To investigate the reliability and feasibility of sentinel lymph node biopsy (SLNB) of papillary thyroid carcinoma using combination of lymphoscintigraphy, the gamma probe and methylene blue staining techniques. Methods Twenty-three consecutive patients with thyroid papillary carcinoma were entered in the study between August 2007 and August 2009. All cases were without clinical evidence of cervical lymph node involvement. The 99Tcm-dextran of 74 MBq (2mCi) was injected intratumorally under ultrasound guidance about 2 h to 5 h prior to surgery. Methylene blue was injected around the tumor during surgery. Preoperative lymphoscintigraphy, intra-operative hand-held gamma probe detecting and methylene blue staining techniques were used to detect the sentinel lymph node (SLN). SLN biopsies were sent to prepare frozen sections and the results were compared with specimen of routine selective neck dissection. Results The SLNs were identified in all cases with the combination techniques. The SLN identification rates were 87.0% and 100% with methylene blue staining and lymphoscintigraphy plus probe scanning, respectively. Metastases in SLNs were revealed by frozen-section histology in 12 patients. In one case, SLNs frozen-section were negetive, but metastasis was detected in routine histology. In other case both SLN and routine histology were negative, but metastasis was detected in non-SLN (level Ⅵ ) neck dissection. The overall accuracy of the SLN biopsy was 91.3%, positive predictive value 100% and negative predictive value 81.8%. Conclusion The results seem the SLN biopsy technique is a feasible and valuable method for detecting cervical lymph node metastasis and is helpful to decide performing neck dissection in patients with cN0 papillary thyroid carcinoma.