| Background&ObjectiveIn recent years,with the improvement of people’s health awareness and ultrasonic diagnostic technology,the incidence of thyroid carcinoma is increasing year by year.Thyroid carcinoma is the most common malignant tumor of the head and neck,among which papillary thyroid carcinoma(PTC)has the highest incidence,accounting for about 80%.The female has higher incidence than male.PTC behaves as an inert growth pattern and has a good prognosis.Although the incidence of distant metastasis is low,the incidence of cervical lymph node metastasis is high,about 30%-80%."Operation+131I+inhibition of thyroid stimulating hormone(TSH)" recognized as the most effective method for the treatment of PTC.However,some patients still had tumor recurrence,lymph node metastasis or distant metastasis,which affected the choice of follow-up treatment and prognosis of patients.Therefore,it is of great clinical significance to determine the qualitative diagnosis of cervical lymph nodes(CLNs)after 131I treatment after thyroid papillary carcinoma surgery.Ultrasound is currently the preferred method for cervical lymph nodes follow-up after PTC surgery,and it is superior to CT about discovering the structure changes inside the lymph nodes.Ultrasound-guided fine-needle aspiration cytology(FNAC)has a high accuracy in determining the benign and malignant of lymph nodes.As report goes that fine-needle aspiration thyroglobulin cytology(FNA-Tg)is a sensitive and specific method to detect the qualitative diagnosis of lymph nodes.Therefore,we aim to search for the better way to diagnose the cervical lymph nodes treated by 131I after PTC surgery through analyzing the ultrasonic characteristics and the single or combined diagnosis of FNAC and FNA-Tg.Methods1.MethodsPatients participate in Multi-disciplinary team(MDT)host by the nuclear medicine department of Zhujiang hospital from April 2019 to March 2020.Part Ⅰ:Inclusion criteria:①after the operation of thyroid papillary carcinoma and treatment of 131I;②highly suspected to be metastatic lymph nodes by ultrasound;③ultrasound-guided fine-needle aspiration cytology and surgical resection.Exclusion criteria:patients with coagulation and other body dysfunction.Part Ⅱ:Inclusion criteria:①after the operation of thyroid papillary carcinoma and treatment of 131I;②Sonographic diagnosis is ambiguous or negative but highly suspected to be metastatic lymph nodes by PET-CT,ECT or MRI;③ultrasoundguided fine-needle aspiration cytology and surgical resection.Exclusion criteria:patients with coagulation and other body dysfunction who cannot tolerate puncture.Part Ⅲ:Inclusion criteria:①after the operation of thyroid papillary carcinoma and treatment of 131I;②suspicious lymph node metastasis was diagnosed by ultrasound,MRI,ECT or PET-CT;③ultrasound-guided fine-needle aspiration cytology and surgical resection.Exclusion criteria:patients with coagulation and other body dysfunction who cannot tolerate puncture.2.Equipment and procedures(1)Equipment:A high-resolution ultrasound system(LOGIQ E9;GE Healthcare,Milwaukee,WI,USA)with a 6-15 MHz linear array transducer.(2)Procedures:The ultrasound examination of thyroid and cervical lymph nodes should be finished before MDT.The patient was required to lie on his/her back in order to exposing the neck completely.Using ML6-15,a linear array probe,under the condition of two-dimensional ultrasound,for scanning the thyroid area and Ⅰ-Ⅶ area of neck.When discovering suspicious lymph nodes,adjusting the probed to acquiring the conventional vertically and horizontally sections of lymph nodes and the best observation section.Measuring the length and short diameter of the lymph nodes and recording the periphery completeness,the internal echo,the hilar structure of the lymph nodes,calcification and cystic degeneration.With or without blood flow and its distribution of suspected lymph nodes were observed by CDFI.FNAC performed on lymph nodes or not should be decided after MDT.FNAC was feasible after the informed consent signed and the examination of the infectious disease and the coagulation function completed.The linear array probe,9L,used for guiding.Patient was in supine position,with the shoulder and back raised fully expose the anterior cervical area.Routine disinfection and whisking the sterile drape.Locate suspicious lymph node and choose the best path,the biopsy needle with 21G was inserted into the target lymph nodes under ultrasonic guidance and acquired lymph node tissue with the negative pressure.When catching sight of tissue in the needle,pulling out and injecting it on the glass slides fixed in 95%alcohol afterwards and deliver it to the pathology department for cytological examination after the tissue a little dry.Diluted the remained blood and tissue in biopsy needle in 3 ml 0.9%saline,and then deliver it to clinical laboratory to detect the contention of Tg.Results1.Part Ⅰ:The CLNs treated by 131I after PTC surgery of this part were highly suspected to be metastatic CLNs by ultrasound.Confirmed by histopathology,the accuracy of ultrasonic diagnosis was up to 81.82%.There was no statistically significant difference between the aspect ratio of metastatic lymph nodes(2.56±1.21)and that of non-metastatic lymph nodes(2.79±1.42)(P>0.05).It proves that the metastatic lymph nodes were still elliptic,but the former were still smaller than the latter.When discovering micro calcification or cystic degeneration inside the LNs,the probability of diagnosing to be metastatic CLNs was 80%and 71.43%,respectively.Metastatic LNs were as high as 80%in the CLNs with the disappearance of hilum structure.The metastatic lymph nodes showed peripheral or mixed blood flow signals in 70.37%.FNAC had a diagnostic accuracy of 75.76%,a positive likelihood ratio approaching 1.63,and a negative likelihood ratio of 0.37.Fisher’s test indicated that Cytopathology and histopathological differences in diagnosis were not statistically significant,P>0.05.No related factors were found for recurrent cervical lymph node metastasis after treated by 131I after PTC surgery.2.Part Ⅱ:The lymph nodes treated with 131I after PTC surgery,which were negative in ultrasound diagnosis or could not be clearly diagnosed but were suspected to be metastatic by other imaging methods,82.45%of which were confirmed to be nonmetastatic lymph nodes by histopathology.The accuracy of ultrasonic diagnosis to be negative was 90.91%,and 33.33%of the lymph nodes that could not be clearly diagnosed by ultrasound still had metastasis.The accuracy rate of FNAC diagnosis was 88.24%,the sensitivity and specificity were 66.67%and 92.86%,respectively.The positive likelihood ratio was close to 9.34,and the negative likelihood ratio was 0.36.Fisher’s test suggested that the difference between cytological pathology and histopathological diagnosis was not statistically significant,P>0.05(Kappa value was 0.60).Multiple imaging diagnosis can guide whether FNAC examination is needed for this part of lymph nodes.3.Part Ⅲ:According to ROC curve,the diagnostic threshold of FNA-Tg is 1.605ng/ml in this study,slightly higher than the 1.0ng/ml in most studies.The diagnostic accuracy is up to 86%,which can promoted the accuracy of FNAC when combined diagnosis.Moreover,the sensitivity of combined diagnosis is higher than diagnosing alone.The best diagnostic efficiency was the combination of three methods,the sensitivity and specificity were 83.33%and 95%,respectively,and the positive likelihood ratio was 16.67。Conclusion1.The metastatic CLNs treated by 131I after PTC surgery have little morphological significance,but the lymphatic hilum structure,blood flow distribution,micro calcification and cystic degeneration are still the important features.2.No related factors were found for recurrent cervical lymph node metastasis after treated by 131I after PTC surgery.3.FNAC should be further confirmed when cervical lymph nodes which could not be clearly diagnosed were still metastasized after 131I treatment after PTC surgery.4.The multiple combined imaging diagnosis can be used to guide whether FNAC examination is needed for lymph nodes with negative ultrasound diagnosis or not definite diagnosis5.The accuracy of ultrasound,FNAC and FNA-Tg combined diagnosis is 88%,which is the optimal diagnosis method in this study and can provide the reliable evidence for CLNs after treated by 131I after PTC surgery. |
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