The Clinical Value Of Papillary Thyroid Carcinoma Central Neck Lymph Node Dissection

Objectives: To discussion the clinical value of central neck lymph nodedissection in papillary thyroid carcinoma, especially thyroid papillarymicrocarcinoma(PTMC), to evaluate the diagnostic significance ofpreoperative ultrasonography of central neck metastasis lymph nodes, andthe clinical significance of preoperative ultrasonography in central neck lymphnode dissection.Methods: The current treatment of thyroid cancer, in view of thecontroversy, that whether routine cleaning central neck lymph node, we took acombination of preoperative ultrasound, routine intraoperative dissection andpostoperative pathologic analysis of prospective studies, the clinical value ofpreoperative assessment methods and the dissection of central area. Collectedand analyzed121cases which come from September2012to December2013and had done about the same standard from the same surgeon in ourdepartment, and that were papillary thyroid carcinoma with central lymphnode dissection, while they had ultrasound examination of the neck beforeoperating, and recorded the sonographic findings of thyroid cancer primarytumor size, location, shape, etc., and cervical lymph nodes (especially centralneck lymph nodes) in size, number, shape, boundary, echo, blood flow,calcification, cortex and medulla boundaries or cystic degeneration and otherfeatures, while recorded the patient’s gender and age. According to thecharacteristic of above ultrasound finding to make a preliminary diagnosis ofthe primary tumor and metastatic lesions. All patients in both the primarytumor resection, while the central region cervical lymph node dissectiontogether with adipose tissue, and pathological diagnosis for the primary tumorhad resected and the central area cleaning tissues. Pathology was confirmedpapillary thyroid carcinoma. Compared the pathologic diagnosis with preoperative ultrasound diagnostic. The statistical analysis of all the data wereperformed by SPSS13.0statistical program,0.05was selected as the standard.Evaluated the value of ultrasound diagnostic about central lymph nodemetastasis between thyroid papillary microcarcinoma andnon-microcarcinoma(non-PTMC) to analyze the factors influencing whichfactored ultrasound diagnosis and the factors that impacted on lymph nodemetastasis, then combined with the patient’s risk factors and the incidence ofpostoperative complications, which further guided the choice of clinicalsurgical approach.Results：In the121patients, the accuracy rate of ultrasound diagnosticthat thyroid papillary microcarcinoma (primary lesion d≤1.0cm) with cervicalcentral lymph node was74.2%(46/62), misdiagnosis rate was61.9%(13/21),the rate of misdiagnosis7.3%(3/41), sensitivity of38.1%(8/21), specificityof92.7%(38/41), positive predictive value of72.7%(8/11), negativepredictive value74.5%(38/51), the value of Kappa was0.3485; while theother59patients with thyroid papillary non-microcarcinoma (primary lesion d＞1.0cm), its accuracy rate was55.9%(33/59), misdiagnosis rate was58.3%(21/36), the rate of misdiagnosis21.7%(5/23), sensitivity was41.7%(15/36),specificity was78.3%(18/23), positive predictive value of75.0%(15/20), andnegative predictive value of46.2%(18/39), the value of Kappa was0.1757.Ultrasound diagnostic accuracy rate of the papillary thyroid carcinoma wasrelatively high, but the two groups were compared with the results ofultrasound diagnosis of central lymph node, the accuracy of the former washigher than the latter, both of their specificity were high, but the specificity ofthe former was higher than the latter, while the sensitivity of the former waslower than the latter. The size and the location of the primary tumor werestatistically significant, with the cervical lymph node metastasis rate(2＝8.941, P＜0.05, and2＝17.975, P＜0.05). Gender and age on the centrallymph node metastasis rate were no statistically significant(2＝0.354, P＞0.05, and2＝1.861, P＞0.05). In thyroid papillary microcarcinoma patientswith postoperative hypocalcaemia was15(8.1%), while thyroid papillary non-microcarcinoma was15(25.4%). Postoperative transient hoarseness inpatients with thyroid papillary microcarcinoma patients andnon-microcarcinoma patients were three cases, respectively,4.8%and5.1%,did not occur in all patients permanent hypocalcaemia and recurrent laryngealnerve injury symptoms and were returned to normal after two weeks.Conclusions: We compared the clinical data of121papillary thyroidcarcinoma cases, which were confirmed by pathological study, it resulted that:1Gender and age on the rate of central neck lymph node metastasis inpapillary thyroid carcinoma were statistically significant (2＝0.354, P＞0.05and2＝1.861, P＞0.05), while the size and the location werestatistically significant (2＝8.941, P＜0.05and2＝17.975, P＜0.05).2The ultrasonography in the diagnosis of papillary thyroid carcinoma andcentral lymph node metastasis were high accuracy rate, it could be used asa relatively safe and reliable way, and to some extent, it guided the choiceof surgical approach.3When the ultrasound diagnosis of cervical central lymph node-positivewas prompted suspiciously in the thyroid papillary microcarcinoma, in thecase of a valid reservation parathyroid and recurrent laryngeal nerve,routine cervical central lymph node dissection was necessary. However,when it prompted negative, we could recommend patients to do theprophylactic central lymph node dissection in conjunction with the patientrisk factors and requirements of patients.4Whether the ultrasound diagnosis of central lymph node was promptedsuspiciously or not in the thyroid papillary microcarcinoma and non-microcarcinoma, the central lymph nodes dissection is necessary.5Surgeon’s skilled techniques could be well separated and protected therecurrent laryngeal nerve and parathyroid glands in surgery, the probabilityof postoperative hypocalcaemia and hoarseness was low, the central lymphnodes dissection did not affect the patient’s postoperative recovery andquality of life.Our results showed that high-frequency color Doppler ultrasound of the neck could diagnose initially the thyroid cancer and cervical lymph nodemetastasis to some extent, but at present a large number of studies had shownthat the metastasis rate of central lymph node in papillary thyroid carcinomawas high. Along with the development of medical technology and skilledoperative techniques, preventive central lymph node dissection could not onlyprevent recurrence and metastasis, but also did not increase the incidence ofpostoperative complications. Prophylactic central lymph node dissection couldbe used as a routine method of surgical resection in thyroid cancer. Theultrasound diagnosis of central lymph nodes can provide more as a reliablereference for clinical, and may further guidance on thyroid cancer clinicians tochoose the method of surgery.