Table 2.
Main characteristics of included studies
| Author | Country | Year | Age (avg. or median) | Male/female | Number of patients | Number of lesions | Reference standard | Type of lesions (number of lesions) | Ultrasound system | Index of elastography | Cut-off value | TP | FP | FN | TN | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Klintworth et al [8] | Germany | 2012 | 53.3 | 27/30 | 57 | 57 | Postoperative pathology | Squamous cell carcinoma (3), mucoepidermoid carcinoma (1), salivary duct carcinoma (1), basal cell carcinoma (1), carcinoma ex pleomorphic adenoma (1), metastatic malignant melanoma (1); pleomorphic adenoma (22), Warthin tumour (20), cystadenoma (2), lipoma (2), cyst (3) | Siemens Ltd., Healthcare Sector, Acuson S2000 | Garland sign | Garland sign (+) | 3 | 2 | 5 | 47 |
| 2 | Yerli et al [24]* | Turkey | 2012 | 47.4 | 15/15 | 30 | 30 | Postoperative pathology (n = 33) or clinical indications, fine-needle aspiration biopsy (n = 3) | Adenocarcinomas (2), mucoepidermoid carcinomas (2), adenoid cystic carcinomas (1), malignant lymphoma (1); Warthin tumours (10), pleomorphic adenomas (10), lymphadenopathies (3), abscesses (1) | Hitachi Medical Systems, EUB-7000 | ES (4-point) | ES3 | 4 | 8 | 2 | 16 |
| 3 | Badea et al [16] | Romania | 2013 | NA | 15/5 | 20 | 20 | postoperative pathology | Parotid carcinomas (6), metastases (2); all pleomorphic adenomas (12) | General Electric GE 7, GE 8, GE 9; Phillips, iU22; Siemens S 2000 | Tactile Elastography or ARFI | NA | 8 | 6 | 0 | 6 |
| 4 | Celebi and Mahmutoglu [17] | Turkey | 2013 | 47.19 | 36/39 | 75 | 81 | Postoperative pathology (n = 73), FNAC (n = 6), both (n = 2) | Lymphoma (9), mucoepidermoid carcinoma (6), adenoid cystic carcinoma (5), metastases (3), myoepithelial malignant tumour (1), pleomorphic adenocarcinoma (2), salivary duct carcinoma (2), acinic cell carcinoma (2) and basal cell carcinoma (2); pleomorphic adenoma (28), Warthin tumour (10), lymphadenopathy (9), cystic adenoma/infected cyst rupture (2) | Siemens Medical Solutions, Siemens S2000 | CSES (4-point) | CSES3 | 19 | 19 | 13 | 30 |
| 5 | Wierzbicka et al [19] | Poland | 2013 | 54 | 27/16 | 43 | 43 | Postoperative pathology | Adenocarcinoma (3), malignant lymphoma (2), clear cell carcinoma (1), non-differentiated cancer (1), squamous cell cancer (1), cancer from pleomorphic adenoma (1) and salivary duct cancer (1); pleomorphic adenoma (23), Warthin tumour (5), monomorphic adenoma (2), neurofibroma (1), cyst (1), basal cell adenoma (1) | Supersonic Imagine, Aixplorer | ES (5-point) | ES4 | 4 | 1 | 6 | 32 |
| 6 | Yu et al [20] | China | 2016 | 45 | NA | 51 | 51 | Postoperative pathology | Mucoepidermoid carcinomas (5), acinic cell carcinomas (3), salivary duct carcinomas (3), basal cell carcinomas (2), adenoid cystic carcinoma (1), adenocarcinoma (1), carcinoma ex pleomorphic adenoma (1); pleomorphic adenoma (16), adenolymphomas (15), basal cell adenomas (2), multiple nodular acidophil adenoma (1), myoepithelioma (1) | Siemens Medical Solutions, Acuson S2000 | SWV | 2.76 m/s | 11 | 1 | 5 | 34 |
| 7 | Altinbas et al [15] | Turkey | 2017 | 60.01 | 26/20 | 46 | 54 | Fine-needle aspiration biopsy (cytological and histological results) | Malignant melanoma (3), salivary duct carcinoma (2), squamous cell carcinoma (1), adenoid cystic carcinoma (1), low-grade adenocarcinoma (1), mucoepidermoid carcinoma (1), Merkel cell carcinoma (1); Warthin tumour (18), pleomorphic adenoma (8), reactive lymphoid hyperplasia (6), lipoma (3), granulomatous inflammation (2), basal cell adenoma (2), lymphoepithelial cyst (1), sialadenitis and abscess (1), sialadenosis (1), primary benign oncocytic neoplasm (1), Rosai-Dorfman disease (1) | GE HealthCare, Logiq S7 Expert | E-index | 3 | 7 | 15 | 3 | 29 |
| 8 | Cantisani et al [7] | Italy | 2017 | 56 | NA | 63 | 63 | Postoperative pathology and FNAC | Mucoepidermoid carcinoma (5), malignant lymphoma (3), squamous cell carcinoma (2), acinic cell carcinoma (2), salivary duct carcinoma (2) and squamous cell carcinoma metastasis (2); pleomorphic adenoma (18), Warthin tumour (17), oncocytoma (5), lymphoepithelial cyst (3), ductal cyst (2), benign vascular tumour (2). | Samsung Medison, Accuvix A30, RS 80 A | ECI | 3.5 | 15 | 5 | 1 | 42 |
| 9 | Herman et al [6]* | Czech Republic | 2017 | 60 | 66/58 | 124 | 124 | Postoperative pathology | Squamous cell carcinoma (8), low grade salivary tumour (6), high grade salivary tumour (7), lymphoma (3), melanoma (2), sarcoma (1), neuroendocrine carcinoma (1); pleomorphic adenoma (49), Warthin tumour (33), other benign lesions (14) including oncocytic adenomas, lipomas, lipomatosis, basal cell adenoma, non-sebaceous lymphadenoma, branchiogenic cyst, and chronic inflammation | SuperSonic Imagine,Aixplorer | CSV | 1025 | 18 | 17 | 10 | 79 |
| 10 | Mansour et al [18]# | Germany | 2017 | 58.6 | NA | 202 | 202 | Postoperative pathology | Primary parotid carcinomas (10), secondary parotid carcinomas (13), non-Hodgkin lymphomas (9); pleomorphic adenomas (64), Warthin tumours (73), basal cell adenomas (6), oncocytomas (3), polymorphic adenomas (2), myoepithelioma (1), sebaceous lymphadenoma (1), ductal dilatations (8), lymphoepithelial cysts (5), cystadenomas (4), chronic inflammations (3) | Siemens Healthcare, Acuson S2000 | ES (3-point) | ES2 | 22 | 126 | 10 | 44 |
Avg. average, FNAC fine needle aspiration cytology, SWV shear wave velocity, CSV coefficient of stiffness variability (maximum of stiffness/minimum of stiffness), CSES consensus sonoelastography scores, ES elastographic scoring, ECI elasticity contrast index, ARFI acoustic radiation force impulse, TP true positive, FN false negative, FP false positive, TN true negative, NA not available
*Missing data provided by corresponding author via e-mail
#Another study [25] from the same department was omitted