Jedryka Marcin A, Klimczak Piotr, Kryszpin Marcin, Matkowski Rafal
Gynecological Oncology, Wroclaw Medical University, Wroclaw, Dolnoslaskie, Poland
Oncological Gynecology, Wroclaw Comprehensive Cancer Center, Wroclaw, Dolnoslaskie, Poland.
Int J Gynecol Cancer. 2020 Sep;30(9):1280-1284. doi: 10.1136/ijgc-2020-001458. Epub 2020 Jul 16.
Superparamagnetic techniques for sentinel lymph node (SLNs) biopsy in breast cancer is well recognized but remains novel in the literature in relation to early stage vulvar cancer. The aim of this study was to compare and validate SLN detection using a superparamagnetic iron oxide tracer and a magnetometer probe compared with the standard procedure with a radioisotope (Tc-technetium 99) and a gamma probe, in patients with vulvar cancer.
Patients were included in the study with squamous vulvar tumors less than 4 cm in diameter and without suspicious groin lymph nodes on preoperative magnetic resonance imaging. Patients must have previously qualified for SLN biopsy with a radiotracer as the standard of care. The primary endpoint was the proportion of successful SLN detection with superparamagnetic iron oxide tracer versus Tc. The secondary endpoints were average number of SLNs retrieved per patient, proportion of SLNs detected (nodal detection rate), and proportion of pathologically positive results (malignancy rate) per patient and per node comparing both SLN detection methods.
A total of 20 patients were included in the study. SLNs were found in all patients with both methods, resulting in similar average distributions (3.1/3.2 SLN per patient). The SLN detection rate per patient was 100% with both techniques. Nodal detection sensitivity was 98.5% for the superparamagnetic technique and 93.8% for the radiotracer. Percentage of metastatic lymph nodes detected was 100% with both tracers. The rate of lymph node positivity was 21.5% (14 lymph nodes with metastases) and for patients 45% (9 patients with nodal metastases). Additionally, SLN tainted brown due to superparamagnetic iron oxide nanoparticles in 19 of 20 patients.
The use of superparamagnetic iron oxide tracer in patients with vulvar cancer seems reliable and not inferior to the standard approach with radiotracer.
超顺磁性技术用于乳腺癌前哨淋巴结（SLN）活检已得到广泛认可，但在早期外阴癌方面在文献中仍属新颖。本研究的目的是比较并验证在患有外阴癌的患者中，使用超顺磁性氧化铁示踪剂和磁力计探头检测SLN与使用放射性同位素（锝-99）和γ探头的标准程序相比的情况。
纳入研究的患者为直径小于4厘米的外阴鳞状肿瘤且术前磁共振成像未发现可疑腹股沟淋巴结。患者此前必须符合以放射性示踪剂作为标准治疗方法进行SLN活检的条件。主要终点是使用超顺磁性氧化铁示踪剂与锝相比成功检测到SLN的比例。次要终点是每位患者回收的SLN平均数量、检测到的SLN比例（淋巴结检测率）以及比较两种SLN检测方法时每位患者和每个淋巴结的病理阳性结果比例（恶性率）。
共有20名患者纳入研究。两种方法在所有患者中均发现了SLN，平均分布相似（每位患者3.1/3.2个SLN）。两种技术每位患者的SLN检测率均为100%。超顺磁性技术的淋巴结检测敏感性为98.5%，放射性示踪剂为93.8%。两种示踪剂检测到的转移淋巴结百分比均为100%。淋巴结阳性率为21.5%（14个淋巴结有转移），患者为45%（9名患者有淋巴结转移）。此外，20名患者中有19名患者的SLN因超顺磁性氧化铁纳米颗粒而被染成褐色。
在外阴癌患者中使用超顺磁性氧化铁示踪剂似乎可靠且不劣于使用放射性示踪剂的标准方法。
