Intraoperative frozen section for determining the extent of surgery in papillary thyroid carcinoma: comprehensive risk factor assessment

Abstract

Background: There is much debate on the optimal treatment approach of papillary thyroid carcinoma (PTC). Different guidelines base recommendations on various risk factors. While diagnosing the various risk factors is difficult due to the technical limitations, intraoperative frozen section (IFS) may be a feasible method. We aim to real-time evaluate the multiple risk factors, including lymph node metastasis (LNM), extrathyroidal extension (ETE), multifocality using IFS, and then identify a more effective surgical plan, which may help avoid the need for a second surgery and improve prognosis of patients.

Methods: We retrospectively reviewed the medical records of 364 patients from January 1, 2021 to December 31, 2021. All the patients were initially recommended to undergo a hemithyroidectomy (HT) with isthmusectomy and ipsilateral central compartment neck dissection (CCND). IFS would be executed immediately. Further total thyroidectomies (TTs) would be performed if: (I) results of IFS showed >5 LNM, or (II) there are 1≤ LNM ≤5 but with ETE and/or multifocal carcinoma. The patients were divided and investigated according to the extent of surgery.

Results: Based on the results of IFS, 72 patients underwent TT. The TT group displayed larger average tumor diameter, greater age, higher average body mass index (BMI), and elevated incidence of hypertension and hyperlipidemia compared to the HT group. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of IFS were 77.61%, 100%, 100%, and 88.46%, respectively.

Conclusions: IFS is a highly reliable procedure. Comprehensively evaluating central compartment LNM, ETE, and multifocal carcinoma through IFS helps identify a more reasonable surgical option under the current clinical consensus, which may thus help avoid the need for a second surgery.

Keywords: Papillary thyroid cancer (PTC); intraoperative frozen section (IFS); lymph node metastases (LNMs); multiple risk factors.

Figure 1

The surgical procedure outcomes. HT, hemithyroidectomy; CCND, central compartment neck dissection; LNM, lymph node metastasis; IFS, intraoperative frozen section; ETE, extrathyroidal extension; TT, total thyroidectomy.

Figure 2

The results of intraoperative frozen section and postoperative routine pathology. FR, lymph nodes retrieved during intraoperative frozen section; RR, lymph nodes retrieved during postoperative routine pathology; FM, lymph node metastases during intraoperative frozen section; RM, lymph node metastases during postoperative routine pathology; LNs, lymph nodes.