Gurleyik Emin, Dogan Sami
Department of Surgery, Faculty of Medicine, Duzce University, Duzce, Turkey.
J Clin Med Res. 2014 Oct;6(5):369-73. doi: 10.14740/jocmr1873w. Epub 2014 Jul 28.
Complete excision is important for proper surgical treatment of thyroid disorders. Functional thyroid tissue can be identified based on the level of serum thyroglobulin (Tg), which is produced only by the thyroid follicular cells, and nuclear scan.
Serum thyroid stimulating hormone (TSH), free thyroxin (FT4), basal (unstimulated) Tg and anti-Tg antibody (anti-Tg ab) were measured at the sixth postoperative month in 100 patients with benign thyroid disorders treated by total thyroidectomy. Thyroid nuclear scan was obtained to identify functional remnant of the thyroid gland. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the Tg levels in assessing thyroid remnant were calculated.
Positive scan showed thyroid remnant in 23 patients, among whom 16 were Tg positive (true positive) and seven were Tg negative (< 0.5 ng/mL) (false negative). In these patients, the nuclear scan revealed pyramidal lobe remnants. In 77 patients with negative scan, the Tg levels were also negative (true negative), and the PPV, NPV, sensitivity, specificity and accuracy of the Tg levels were 100%, 92%, 70%, 100% and 93%, respectively.
The positive basal Tg (> 0.5 ng/mL) level accurately indicated the functional thyroid remnant after total thyroidectomy. The negative Tg (< 0.5 ng/mL) level supported complete excision of the thyroid gland. The surgical completeness of total thyroidectomy was accurately evaluated based on the serum Tg levels. Therefore, serum Tg levels should be measured in postoperative follow-up to determine the completeness of total thyroidectomy.
完整切除对于甲状腺疾病的恰当手术治疗很重要。功能性甲状腺组织可根据仅由甲状腺滤泡细胞产生的血清甲状腺球蛋白（Tg）水平及核素扫描来识别。
对100例行甲状腺全切除术治疗的良性甲状腺疾病患者在术后第6个月测定血清促甲状腺激素（TSH）、游离甲状腺素（FT4）、基础（未刺激）Tg及抗Tg抗体（抗Tg ab）。进行甲状腺核素扫描以识别甲状腺的功能性残余组织。计算Tg水平在评估甲状腺残余组织方面的敏感性、特异性、准确性、阳性预测值（PPV）和阴性预测值（NPV）。
扫描阳性显示23例患者存在甲状腺残余组织，其中16例Tg阳性（真阳性），7例Tg阴性（<0.5 ng/mL）（假阴性）。在这些患者中，核素扫描显示为锥状叶残余组织。在77例扫描阴性的患者中，Tg水平也为阴性（真阴性），Tg水平的PPV、NPV、敏感性、特异性和准确性分别为100%、92%、70%、100%和93%。
基础Tg（>0.5 ng/mL）阳性水平准确表明甲状腺全切除术后的功能性甲状腺残余组织。Tg阴性（<0.5 ng/mL）水平支持甲状腺的完整切除。根据血清Tg水平可准确评估甲状腺全切除术的手术完整性。因此，术后随访应测定血清Tg水平以确定甲状腺全切除术的完整性。
