Preoperative Prediction for the Location of Parotid Gland Tumors by Using Anatomical Landmarks

Korean Journal of Head & Neck Oncology 2006;22(1):29-32.
Published online May 30, 2006.

Chi Young Lim;Kook Jin Kim;Sung Ju Lim;Jan dee Lee;Kee Hyun Nam;Hang Seok Chang;Woong Youn Chung;Hong Shik Choi;Cheong Soo Park

수술 전 이하선 종괴의 위치파악에 이용하는 해부학적 경계표의 유용도

임치영;김국진;임성주;이잔디;남기현;장항석;정웅윤;최홍식;박정수

Abstract

Background: The location of parotid gland tumors can influence the duration and the difficulty of the operation. If the information about tumor location was available preoperatively, it would allow accurate operative planning and counseling of patients in terms of the length of the operation and the potential morbidity.
Methods
This study was based on a retrospective review of 100 patients with parotid gland tumors underwent parotidectomy from January 2000 to October 2005 at Yong-Dong Severance Hospital. Based on computed tomographic(CT) scan findings, 4 landmarks such as facial nerve(FN) line, Utrecht(U) line, Conn's are(CA), and retromandibular vein (RV) were drawn on the scans in same plane. The location of tumors were determined by the landmarks and confirmed by the operative findings. The accuracy of each landmarks was evaluated. To find out the accuracies according to tumor size, the tumors were divided into 2 groups; less than 2 cm and larger than 2 cm in diameter.
Results
U line was the most accurate(94%), sensitive(89.3%) and specific(97.7%) in predicting tumor location of the parotid gland. However, in small tumors less than 2cm, FN line (p=0.022) and RV criteria (p=0.028) were more reliable in accuracy.
Conclusion
CA, FN line, U line, and RV are all useful landmarks in preoperative prediction for the location of parotid gland tumors. However, U line was the most accurate, but we must consider that proper landmark should be used in prediction according to the size of tumor because the accuracy of landmark may change.

Key Words: Parotid gland tumor, Tumor localization, Landmark