Utility of sentinel lymph node biopsy for thyroid cancer: a comprehensive review

Sentinel lymph node mapping: current applications and future perspectives in thyroid carcinoma

Sentinel lymph node (SLN) mapping is a standard, minimally-invasive diagnostic method in the surgical treatment of many solid tumors, as for example melanoma and breast cancer, for detecting the presence of regional nodal metastases. A negative SLN accurately indicates the absence of metastases in the other regional lymph nodes (LN), thus avoiding unnecessary lymph nodal dissection. Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma (TC) with cervical LN metastases at diagnosis in 20-90%, and nodal involvement correlates with local persistence/recurrence. The SLN in PTC is an intraoperative method for staging preoperative N0 patients and for detecting metastatic LNs "in and outside" the cervical LN central compartment; it represents an alternative method to prophylactic central neck node dissection. In this review we summarize different methods and results of the use of SLN in TC. The SLN identification techniques currently used include the selective vital-dye (VD) method, 99mTc-nanocolloid planar lymphoscintigraphy with intraoperative use of a hand-held gamma probe (LS), the combination LS + VD, and the combination LS and preoperative SPECT-CT (LS + SPECT/CT). The application of the SLN procedure in TC has been described in many studies, however, the techniques are heterogeneous, and the role of SLN in TC, with indications, results, advantages and limits, is still debated.

Quality indicators for thyroid cancer surgery: current perspective

INTRODUCTION

While the disease specific mortality of differentiated thyroid cancer has remained low with current treatments, its incidence has been steadily rising over the past several decades, and cancer related recurrence and morbidity have remained a significant problem. Quality indicators currently employed are relevant to the surgical intervention, but do not necessarily reflect oncological outcomes. Therefore, thyroid cancer specific surgical quality indicators, that offer insight into risk of cancer related morbidity and mortality are needed.

AREAS COVERED

This review aims to discuss the role of measuring quality in thyroid surgical oncology and carry out a comprehensive review of potential quality indicators for thyroid cancer operations. The three quality indicators reviewed here are the postoperative radioactive iodine update by remnant thyroid tissue, the proportion of resected lymph nodes with evidence of metastases, and the post-operative serum thyroglobulin level. Expert commentary: Together, these quality indicators may be utilized to guide improvement of the quality of surgical care for this unique patient population. A critical future step in establishing the role of quality indicators for thyroid cancer surgery is the determination of cutoff values of each indicator in an evidence-based manner.