Papillary Thyroid Cancer: Radiographic SLNB May Lead to Management Change
The use of the radioguided sentinel lymph node biopsy (rSLNB) technique may lead to management change in more than 33% of patients with papillary thyroid cancer.
The use of the radioguided sentinel lymph node biopsy (rSLNB) technique may lead to management change in more than 33% of patients with papillary thyroid cancer (PTC), a study published in JAMA Otolaryngology–Head & Neck Surgery has shown.1
Both single-photon emission computed tomography/computed tomography (SPECT/CT) and rSLNB are techniques that may improve the identification of sentinel lymph node (SLN) metastases in patients with PTC. Previous research has demonstrated that these novel techniques lead to significant changes in PTC management by reducing understaging, increasing the need for lateral lymphadenectomy, and decreasing the necessity of central lymphadenectomy.
Researchers investigated associations among the presence of lymph node metastases in patients with PTC and clinical and pathologic features identified using SPECT/CT and rSLNB by enrolling 42 patients with thyroid nodules, which were either suspicious for papillary carcinoma or determined to be malignant on cytology examination.
All participants underwent preoperative SLN mapping after an ultrasound-guided peritumoral injection of Technetium-99m-labeled nanocolloid. Fifteen minutes after injection of the radiotracer, patients underwent SPECT/CT to obtain cervical images. About 2 hours after imaging, intraoperative rSLNB was performed to remove all SLNs and non-SLNs from the same compartment.
Results showed that among the 37 evaluable patients, 62.2% had T1 cancer, 21.6% had T2 disease, and 16.2% had stage T3. Researchers identified SLNs in 92% of patients, and 46% had SLN metastases; 18% had metastases in the lateral compartment. Investigators also found that the presence of SLN metastases was significantly associated with tumor size (odd ratio, 1.06; 95% CI, 1.00-1.13; P = .02).
Among the 46% of patients with SLN metastases, all had their management changed by their physician; these patients subsequently underwent higher radioiodine ablation doses with closer clinical surveillance. The rSLNB technique was directly responsible for management change in 37.8% of patients.
1. Cabrera RN, Chone CT, Zantut-Wittmann DE, et al. The role of SPECT/CT lymphoscintigraphy and radioguided sentinel lymph node biopsy in managing papillary thyroid cancer. JAMA Otolaryngol Head Neck Surg. 2016 Jun 30. doi: 10.1001/jamaoto.2016.1227 [Epub ahead of print]