Feasibility of FDG-PET/CT for the initial diagnosis of papillary thyroid cancer.

To assess the role of [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) as a preoperative diagnostic tool in papillary thyroid carcinoma (PTC). From 2011 to 2014, 197 patients with PTC (246 tumor foci in all) underwent FDG-PET. Among these patients, 46 underwent neck dissection for lateral neck metastasis. According to the FDG avidity of the tumor foci or lateral neck metastasis, factors associated with the prognostic value were evaluated by univariate and multivariate logistic regression analyses. Among the 197 patients, 7 (3.6 %) were incidentally found to have non-thyroid origin malignancy. Additionally, 63.0 % (155/246) of PTC foci showed FDG uptake on PET/CT. Univariate analysis showed that the tumor size, the presence of extrathyroidal extension, BRAF mutation, and Hashimoto thyroiditis were associated with FDG avidity. However, except for pathological extrathyroidal extension, the other factors showed statistically significant correlations with FDG avidity (p < 0.001, p = 0.008, and p = 0.009, respectively). FDG uptake in lateral neck node metastasis showed high specificity and negative predictive value (NPV). In four cases of nonspecific findings on ultrasonography (USG)/CT, FDG avidity was helpful to diagnose the presence of lateral neck metastasis. The maximum standardized uptake value (SUVmax) of PET/CT was correlated with the maximum diameter of the involved lateral node. FDG avidity did not show any significance in the recurrence-free survival of both the thyroid tumor and lateral neck metastasis. The FDG avidity of PTC did not show prognostic predictive meaning. However, in the case of lateral neck metastasis, FDG avidity showed high sensitivity and NPV, and could provide better information in cases of nonspecific findings on USG and CT.

Surgeon-performed ultrasound-guided fine-needle aspiration cytology of head and neck mass lesions: sampling adequacy and diagnostic accuracy.

BACKGROUND: Studies of surgeon-performed ultrasound-guided fine-needle aspiration cytology (US-FNAC) have been limited largely to thyroid nodules. This study evaluated the sampling adequacy and diagnostic accuracy of surgeon-performed US-FNAC for a large range of head and neck mass lesions, including lesions of the thyroid, salivary glands, and lymph nodes. METHODS: The study included 617 cases of US-FNAC performed by a single surgeon between 2009 and 2013. Their medical histories and ultrasound (US) findings were retrospectively reviewed. Sample adequacy was analyzed according to the surgeon's experience, anatomic tumor location, and US tumor characteristics. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of FNAC were calculated after correlation with the surgical histopathologic results. RESULTS: The overall adequacy rate for surgeon-performed US-FNAC was 91.9 % (567/617). Inadequate specimens were obtained from 9.7 % (29/282) of the thyroid glands, 6.1 % of the salivary glands (6/98), and 6.3 % (15/237) of the lymph nodes. The effect of the surgeon's experience plateaued (inadequate sampling rate, 6-8 %) after 100 US-FNAC procedures. Inadequate sampling was associated with tumor characteristics such as cystic change and rim calcification. Overall, US-FNAC showed a sensitivity of 88.2 %, a specificity of 98.2 %, a PPV of 98.5 %, an NPV of 85.7 %, and a diagnostic accuracy of 91.6 %. CONCLUSION: With proper training and experience managing at least 100 US-FNAC cases, surgeons can ensure a low inadequate sampling rate and good diagnostic accuracy for a range of head and neck mass lesions.

A rapid method for simultaneous screening of multi-gene mutations associated with hearing loss in the Korean population.

Hearing loss (HL) is a congenital disease with a high prevalence, and patients with hearing loss need early diagnosis for treatment and prevention. The GJB2, MT-RNR1, and SLC26A4 genes have been reported as common causative genes of hearing loss in the Korean population and some mutations of these genes are the most common mutations associated with hearing loss. Accordingly, we developed a method for the simultaneous detection of seven mutations (c.235delC of GJB2, c.439A>G, c.919-2A>G, c.1149+3A>G, c.1229C>T, c.2168A>G of SLC26A4, and m.1555A>G of the MT-RNR1 gene) using multiplex SNaPshot minisequencing to enable rapid diagnosis of hereditary hearing loss. This method was confirmed in patients with hearing loss and used for genetic diagnosis of controls with normal hearing and neonates. We found that 4.06% of individuals with normal hearing and 4.32% of neonates were heterozygous carriers. In addition, we detected that an individual is heterozygous for two different mutations of GJB2 and SLC26A4 gene, respectively and one normal hearing showing the heteroplasmy of m.1555A>G. These genotypes corresponded to those determined by direct sequencing. Overall, we successfully developed a robust and cost-effective diagnosis method that detects common causative mutations of hearing loss in the Korean population. This method will be possible to detect up to 40% causative mutations associated with prelingual HL in the Korean population and serve as a useful genetic technique for diagnosis of hearing loss for patients, carriers, neonates, and fetuses.