[Value of the endoscopic diagnosis on the lesions of the skull base in postradiotherapeutic patients with nasopharyngeal carcinoma].

To evaluate the diagnostic value of the endoscopic biopsy operation to the lesions of the skull base in the patients with nasopharyngealcarcinoma after radiotherapy. From February 2006 to February 2010, 84 patients with nasopharyngeal carcinoma suffered from the lesions of the skull base after radiotherapy were included in this study. The relationship between the pathologic results of endoscopic biopsies from the skull base and the imaging results by Magnetic Resonance Imaging(MRI) was compared and discussed. The relationship between the pathologic results and more than 2-years' follow-up was also investigated. There were 71 cases with clivus, 5 cases with pterygopalatine fossa and infratemporal fossa, 4 cases with parapharyngeal space, and 4 cases with cavernous sinus. The pathologic results of endoscopic biopsies indicated that 35 cases with recurrence including 30 case with poorly differentiated squamous cell carcinomas, 5 cases with cancer nests, 49 cases with non-tumor. Chi-square test showed that there was close relationship between MRI and pathologic results (<0.05). In the patients followed up over 2 years, the pathologic results showed 28 cases with recurrence, 48 cases with non-tumor. MRI showed 36 cases with recurrence, 40 cases with non-tumor. But during follow-up, 30 cases were proved to be recurrent and 46 cases had non-tumor. However, Chi-square test showed that there was no statistically significance between the pathological results and follow-up(=0.62). The sensitivity, specificity and diagnostic accuracy of the endoscopic diagnosis were 90.0%, 97.8% and 95.0%. Chi-square test also showed that there was no statistically significance between MRI and follow-up (=0.24). The sensitivity, specificity and diagnostic accuracy of MRI were 80.0%, 73.9% and 76.0%. The endoscopic method is a specific, sensitive, safe, effective and minimally invasive in diagnosis of lesions of the skull base in postradiotherapeutic patients with nasopharyngeal carcinoma.