Value of PET-CT and MRI in the diagnosis of recurrence cases after radiotherapy of nasopharyngeal carcinoma

Objective:To evaluate the value of PET-CT and MRI in the diagnosis of recurrence after radiotherapy of nasopharyngeal carcinoma.Method:Twenty one cases of nasopharyngeal carcinoma patients after radiotherapy underwent PET-CT and MRI examination.The rate of sensitivity,specificity,omission diagnosis,misdiagnosis and accuracy of PET-CT and MRI in the diagnosis of recurrence after radiotherapy of nasopharyngeal carcinoma were calculated according to pathology biopsy and clinical follow-up,and compare the rate of accuracy between PET-CT and MRI.Results:The rates of sensitivity,specificity,omission diagnosis,misdiagnosis and accuracy of PET-CT in the diagnosis of recurrence after radiotherapy of nasopharyngeal carcinoma were 92.3%(12/13),100.00%(8/8),7.7%(1/13),0.00%(0/8) and 95.2%(20/21).The rate of sensitivity,specificity,omission diagnosis,misdiagnosis and accuracy of MRI were 100.00%(13/13),87.5%(7/8),0.00%(0/13),12.5%(1/8) and 95.2%(20/21).The difference of accuracy between PET-CT and MRI was not statistically significant(P﹥0.05).Conclusion:The value of PET-CT and MRI in the diagnosis of nasopharyngeal carcinoma recurrence after radiotherapy is very important.There is no significant difference between them.Both of them have their own advantages and disadvantages.They should be combined to improve the rate of accuracy in diagnosis of nasopharyngeal cancer recurrence after radiotherapy.