[Contrast-enhanced CT for the diagnosis of extracapsular spread by head and neck cancers: a systematic review and meta analysis].

Purpose: This study aimed to assess the diagnostic efficacy of contrast-enhanced CT in the screening of extracapsular spread by head and neck cancers.

Methods: Electronic databases, including MEDLINE, EMBASE,CBM,CNKI and SciencePaper Online were searched electronically. Hand-searching was also performed.