Korean J Otorhinolaryngol-Head Neck Surg.  2019 Mar;62(3):176-181. 10.3342/kjorl-hns.2018.00577.

Prediction of Location of the Parotid Tumors that Cross Over Anatomical Criteria for Facial Nerve on Computed Tomography

• Jang GH
• Kim DS
• Jung YD
• Seo YT
• Kim BM
• Kil BK
• Lee DW
• Kim HK
• Kim JK

• KMID: 2442061
• DOI: http://doi.org/10.3342/kjorl-hns.2018.00577

Abstract

BACKGROUND AND OBJECTIVES
To find more accurate way to determine the location of parotid tumors that cross anatomical criteria for the facial nerve (FN).
SUBJECTS AND METHOD
Two hundred patients were included in the study and retrospectively studied. Five anatomical criteria were used to predict the location of parotid tumors on computed tomography (CT). Deep portion of tumors was measured and then, cut-off value was obtained after receiver operator curve analysis. The location of tumor was predicted by using the cut-off value and by the conventional way, in which the side where most of the tumor is located is determined as the tumor site.
RESULTS
The parotid tumors were located in superficial lobes in 148 cases, and in deep lobes in 52 cases by operative record. The tumors that cross the anatomical criteria were defined as "˜crossing tumor.' The cut-off values for prediction of "˜crossing tumor' location on CT were 6.7 mm for anatomical line, 6.4 mm for FN line, 11.2 mm for retromandibular vein, 4.9 mm for Utrecht line and 3.8 mm for Conn's arc. The accuracy of 5 anatomical criteria for "˜crossing tumor' was between 55.9% and 81.6% when the cut-off value was used, whereas the accuracy was between 25.7% and 68.9% when conventional way was used.
CONCLUSION
In cases of "˜crossing tumor,' the cut-off value obtained by measurement of deep portion of tumor can be applied to improve the diagnostic performance for the prediction of tumor location.

Keyword

Facial nerve; Parotid gland; Parotid neoplasm

MeSH Terms

Facial Nerve*
Humans
Methods
Parotid Gland
Parotid Neoplasms
Retrospective Studies
Veins