Sentinel lymph node biopsy using carbon nanoparticles for Chinese patients with papillary thyroid microcarcinoma

Aims: To compare the efficacies of methylene blue (MB) and carbon nanoparticles (CNs) as tracers for sentinel lymph node biopsy (SLNB), and assess the value of SLNB in predicting the cervical LN status of patients with thyroid microcarcinoma. Methods: This retrospective analysis comprised 200 thyroid microcarcinoma patients who underwent intraoperative SLNB. Among them, 100 patients were injected with MB dye. The other 100 patients received a CN suspension injection. Routine pathological examination was performed in all resected specimens. Results: SLNs detected in the experimental and control groups were 126 and 102, respectively, of which the metastatic LNs confirmed by histopathology were 77 and 48, respectively. The staining rate of cervical level VI LNs in the experimental group was significantly higher than that in the control group (P < 0.001). For the CN method, the sensitivity, specificity, accuracy rate, and false negative rate were 93.3%, 100%, 97%, and 5.2%, respectively, whereas the corresponding figures for the MB method were 80.6%, 100%, 93%, and 9.9%, respectively. The positive rate of cancer metastases for SLNs in the experimental group was 61.1%, which is significantly higher than that in the control group (47.1%; P = 0.034). Conclusions: In contrast to the MB method, CNs can maintain the durability of SLN imaging and accurately forecast the LN status of patients with thyroid microcarcinoma; in addition, the CN method was found to be feasible and repeatable. The CN method better aids the screening and selection of patients who are most likely to benefit from cervical LN dissection. (C) 2012 Elsevier Ltd. All rights reserved.