Accuracy of Preoperative Imaging in Detecting Nodal Extracapsular Spread in Oral Cavity Squamous Cell Carcinoma

Fellows’ Journal Club

Editor’s Comment

A group of 111 consecutive patients with untreated oral cavity squamous cell carcinoma and available preoperative imaging and subsequent lymph node dissection was studied. Twenty nine subjects had radiographically determined extracapsular spread. Imaging sensitivity and specificity for extracapsular spread were 68% and 88%, respectively. Necrosis, irregular borders, and gross invasion were independently correlated with pathologically proved extracapsular spread.

Abstract

A, A right level IIA lymph node (arrow) in a patient with OCSCC. This rounded low-attenuation node has irregular borders and fat stranding. Imaging prospectively diagnosed ECS, which was confirmed with pathologic examination (true-positive result). B, A right level IIA lymph node (arrow) in a patient with OCSCC. This small 1-cm lymph node shows subtle fat stranding. Imaging prospectively diagnosed ECS, which was confirmed with pathologic examination (true-positive result). C, A right level IIA lymph node (arrows) in a patient with OCSCC. This large necrotic node demonstrates invasion of the adjacent sternocleidomastoid muscle. Imaging prospectively diagnosed ECS, which was confirmed with pathologic examination (true-positive result).
A, A right level IIA lymph node (arrow) in a patient with OCSCC. This rounded low-attenuation node has irregular borders and fat stranding. Imaging prospectively diagnosed ECS, which was confirmed with pathologic examination (true-positive result). B, A right level IIA lymph node (arrow) in a patient with OCSCC. This small 1-cm lymph node shows subtle fat stranding. Imaging prospectively diagnosed ECS, which was confirmed with pathologic examination (true-positive result). C, A right level IIA lymph node (arrows) in a patient with OCSCC. This large necrotic node demonstrates invasion of the adjacent sternocleidomastoid muscle. Imaging prospectively diagnosed ECS, which was confirmed with pathologic examination (true-positive result).

Background and Purpose

The increasing impact of diagnosing extracapsular spread by using imaging, especially in patients with oropharyngeal squamous cell carcinoma, highlights the need to rigorously evaluate the diagnostic accuracy of imaging. Previous analysis suggested 62.5%–80.9% sensitivity and 60%–72.7% specificity. Our goals were to evaluate the accuracy of imaging in diagnosing extracapsular spread in a cohort of patients with oral cavity squamous cell carcinoma (pathologic confirmation of extracapsular spread routinely available), as a proxy for oropharyngeal squamous cell carcinoma, and to independently assess the reliability of imaging features (radiographic lymph node necrosis, irregular borders/stranding, gross invasion, and/or node size) in predicting pathologically proven extracapsular spread.

Materials and Methods

One hundred eleven consecutive patients with untreated oral cavity squamous cell carcinoma and available preoperative imaging and subsequent lymph node dissection were studied. Two neuroradiologists blinded to pathologically proven extracapsular spread status and previous radiology reports independently reviewed all images to evaluate the largest suspicious lymph node along the expected drainage pathway. Radiologic results were correlated with pathologic results from the neck dissections.

Results

Of 111 patients, 29 had radiographically determined extracapsular spread. Pathologic examination revealed that 28 of 111 (25%) had pathologically proven extracapsular spread. Imaging sensitivity and specificity for extracapsular spread were 68% and 88%, respectively. Radiographs were positive for lymph node necrosis in 84% of the patients in the pathology-proven extracapsular spread group and negative in only 7% of those in the pathologically proven extracapsular spread–negative group. On logistic regression analysis, necrosis (P = .001), irregular borders (P = .055), and gross invasion (P = .068) were independently correlated with pathologically proven extracapsular spread.

Conclusions

Although the specificity of cross-sectional imaging for extracapsular spread was high, the sensitivity was low. Combined logistic regression analysis found that the presence of necrosis was the best radiologic predictor of pathologically proven extracapsular spread, and irregular borders and gross invasion were nearly independently significant.

Read this article: http://bit.ly/OralCavitySCC

Accuracy of Preoperative Imaging in Detecting Nodal Extracapsular Spread in Oral Cavity Squamous Cell Carcinoma
jross
Jeffrey Ross • Mayo Clinic, Phoenix

Dr. Jeffrey S. Ross is a Professor of Radiology at the Mayo Clinic College of Medicine, and practices neuroradiology at the Mayo Clinic in Phoenix, Arizona. His publications include over 100 peer-reviewed articles, nearly 60 non-refereed articles, 33 book chapters, and 10 books. He was an AJNR Senior Editor from 2006-2015, is a member of the editorial board for 3 other journals, and a manuscript reviewer for 10 journals. He became Editor-in-Chief of the AJNR in July 2015. He received the Gold Medal Award from the ASSR in 2013.