Value of sentinel lymph node biopsy in papillary thyroid cancer: initial results of a prospective trial.
The objectives of the study were to evaluate the performance of sentinel lymph node biopsy (SLNB) in detecting occult metastases in papillary thyroid carcinoma (PTC) and to correlate their presence to tumor and patient characteristics. Twenty-three clinically node-negative PTC patients (21 females, mean age 48.4 years) were prospectively enrolled. Patients were submitted to sentinel lymph node (SLN) lymphoscintigraphy prior to total thyroidectomy. Ultrasound-guided peritumoral injections of (99m)Tc-phytate (7.4 MBq) were performed. Cervical single-photon emission computed tomography and computed tomography (SPECT/CT) images were acquired 15 min after radiotracer injection and 2 h prior to surgery. Intra-operatively, SLNs were located with a gamma probe and removed along with non-SLNs located in the same neck compartment. Papillary thyroid carcinoma, SLNs and non-SLNs were submitted to histopathology analysis. Sentinel lymph nodes were located in levels: II in 34.7 % of patients; III in 26 %; IV in 30.4 %; V in 4.3 %; VI in 82.6 % and VII in 4.3 %. Metastases in the SLN were noted in seven patients (30.4 %), in non-SLN in three patients (13.1 %), and in the lateral compartments in 20 % of patients. There were significant associations between lymph node (LN) metastases and the presence of angio-lymphatic invasion (p = 0.04), extra-thyroid extension (p = 0.03) and tumor size (p = 0.003). No correlations were noted among LN metastases and patient age, gender, stimulated thyroglobulin levels, positive surgical margins, aggressive histology and multifocal lesions. Sentinel lymph node biopsy can detect occult metastases in PTC. The risk of a metastatic SLN was associated with extra-thyroid extension, larger tumors and angio-lymphatic invasion. This may help guide future neck dissection, patient surveillance and radioiodine therapy doses.
Division of Nuclear Medicine, Department of Radiology, Campinas State University (UNICAMP), Av. Zeferino Vaz, S/N Cx, Postal 6142, CEP 13081-970, Campinas, Brazil. raquelcabrera@yahoo.com.br.
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Cabrera
Department of Otorhinolaryngology, Campinas State University (UNICAMP), Campinas, Brazil.
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Chone
Division of Endocrinology, Campinas State University (UNICAMP), Campinas, Brazil.
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Zantut-Wittmann
Department of Pathology, Campinas State University (UNICAMP), Campinas, Brazil.
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Matos
Department of Radiology, Campinas State University (UNICAMP), Campinas, Brazil.
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Ferreira
Department of Otorhinolaryngology, Campinas State University (UNICAMP), Campinas, Brazil.
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Pereira
Division of Nuclear Medicine, Department of Radiology, Campinas State University (UNICAMP), Av. Zeferino Vaz, S/N Cx, Postal 6142, CEP 13081-970, Campinas, Brazil.
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Ferrari
Division of Nuclear Medicine, Department of Radiology, Campinas State University (UNICAMP), Av. Zeferino Vaz, S/N Cx, Postal 6142, CEP 13081-970, Campinas, Brazil.
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Santos
Department of Otorhinolaryngology, Campinas State University (UNICAMP), Campinas, Brazil.
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Crespo
Division of Nuclear Medicine, Department of Radiology, Campinas State University (UNICAMP), Av. Zeferino Vaz, S/N Cx, Postal 6142, CEP 13081-970, Campinas, Brazil.
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Etchebehere
D002277:Carcinoma / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D061305:Lymphoscintigraphy; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging; D011446:Prospective Studies; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D013965:Thyroidectomy; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed