Various imaging modalities for the detection of salivary gland lesions: the advantages of 201Tl SPET

Accuracy of diagnosis of salivary gland tumors with the use of ultrasonography, computed tomography, and magnetic resonance imaging: a meta-analysis

OBJECTIVE

To compare ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) for clinical differential diagnosis in patients with salivary gland tumor (SGT).

STUDY DESIGN

Six databases were used to search the literature published between 1982 and 2013. Histologic diagnosis was required as standard diagnosis. Pooled estimate for sensitivity, specificity, summary receiver-operating characteristic curve (SROC) and area under curve (AUC) were calculated and compared using STATA and Meta-Disc statistical software.

RESULTS

Nineteen articles were included. Pooled sensitivity for US, CT, and MRI was 0.629 (95% confidence interval [CI] 0.52-0.73), 0.830 (95% CI 0.74-0.90), and 0.807 (95% CI 0.73-0.87), respectively; pooled specificity for US, CT, and MRI was 0.920 (95% CI 0.89-0.94), 0.851 (95% CI 0.79-0.90), and 0.886 (95% CI 0.85-0.92), respectively. The AUC under SROC for US, CT, and MRI was 0.934 ± 0.058, 0.912 ± 0.889, and 0.903 ± 0.045, respectively.

CONCLUSIONS

CT is recommended, as it is an effective imaging tool for differential diagnosis in patients with primary SGT, and MRI is suggested for differential diagnosis between benign and malignant GSTs because of its highest sensitivity and specificity.

Salivary gland tumors: A 20-year review of clinical diagnostic accuracy at a single center

Obtaining reliable pre-operative diagnosis is crucial in planning treatment for patients with salivary gland tumors. The purpose of this study was to evaluate the accuracy of pre-operative clinical diagnosis of salivary gland tumors managed at a single tertiary university hospital over a period of 20 years. A retrospective analysis of the period between 1992 and 2011 was carried out to review the cases of patients with salivary gland tumors. A total of 101 patients were enrolled and general data were described. Clinical diagnosis was compared with the final pathological diagnosis to reveal the clinical diagnostic accuracy. Of the parotid and submandibular gland tumors, 86 and 67% were benign, respectively. The clinical diagnostic accuracies for diagnosis of parotid tumors as benign or malignant were 100 and 57%, respectively. The clinical diagnostic accuracies for diagnosis of submandibular tumors as benign or malignant were 67%. Therefore, the overall clinical judgment of benign and malignant tumors in the submandibular gland is unreliable. The accuracy for a parotid tumor to be clinically interpreted as benign was 100%. While it is difficult to draw any conclusion for non-parotid gland tumors, surgical intervention should be recommended in patients with parotid tumors clinically suspected to be malignant, and all submandibular, sublingual and minor salivary gland tumors.

Differences between 99mTc-sestamibi and 99mTc-tetrofosmin uptake in thyroid and salivary glands: comparison with 99mTc-pertechnetate in 86 subjects

Tc-tetrofosmin seems to show a prolonged thyroid retention when compared with Tc-sestamibi; this may explain its poorer performance in the dual-phase parathyroid scintigraphy. In order to verify objectively whether and to what extent Tc-sestamibi and Tc-tetrofosmin uptake and retention differ in the thyroid gland, we performed a head-to-head comparison between the tracers in 86 euthyroid subjects enrolled in five centres. Data were compared with those of Tc-pertechnetate obtained from the same subjects. For comparison purposes, quantitative data from the salivary glands were also obtained. Tc-sestamibi showed a higher early thyroid uptake (2.26+/-0.52 vs. 2.01+/-0.49, respectively; P<0.002) and a lower retention (1.4+/-0.37 vs. 1.65+/-0.58, respectively; P<0.002) when compared with Tc-tetrofosmin. This finding provides an objective basis for the poorer results of Tc-tetrofosmin in dual-phase parathyroid scintigraphy. Delayed Tc-tetrofosmin salivary gland uptake was unexpectedly high and approached the Tc-pertechnetate value (2.29+/-0.56 vs. 2.46+/-0.75, respectively; P =not significant). This finding should be kept in mind in order to avoid interpretation pitfalls in thyroid and parathyroid imaging with Tc-tetrofosmin, as well as in other oncological imaging of the neck region. This study definitely establishes that Tc-tetrofosmin and Tc-sestamibi are not twin but rather sibling tracers.

Electrical impedance scanning used in addition to ultrasound for the verification of submandibular and parotid lesions: initial results

OBJECTIVES

Different dielectric properties of cancerous tissues are correlated with increased conductance potentially measurable using Electrical Impedance Scanning (EIS). Sonographically based differentiation of lesions in the salivary glands remains difficult. The clinical value of EIS used additionally to Ultrasound was investigated.

METHODS

Sonographically suspicious lesions of parotid (n = 25) and submandibular (n = 16) glands were examined using TransScan TS2000 (TransScan Medical, Israel; distributed by Siemens, Sweden). Bright focal spots representing areas of high conductance were read as positive; absence of a focal spot (ie, homogeneous gray) was read as negative. All lesions were histopathologically proved.

RESULTS

14/15 malignant (93.3%) and 13/26 benign lesions (50.0%) were correctly detected using EIS, NPV 93%, PPV 52%. All cases of squamous cell carcinoma were correctly identified. Lymph node relapse of T-cell lymphoma, lymph node relapse of malignant melanoma, malignant hemangioendothelioma and 2/3 adenocystic carcinoma (primary metastases) were correctly detected.

CONCLUSIONS

Our initial results suggest EIS to be of interest when used adjunctively to ultrasound for the identification of malignant lesions of the salivary glands. However, low specificity induced in part by current technical restrictions (bone interference, skin alterations, contact artifacts, prominence of the lesions) limit this clinical application.