Objective：To study CT diagnosis and different ia diagnosis of nasoph aryngeal recurrence after radiation therapy.Methods:All the cases have been observed through axial and coronary scanning before

during and after radiation therapy continually for four years.Results：Within two w eeks after the start of the first course radiation treatment on nasopharyngeal c ancer

edema of different levels appeared on tumor-affected parts through CT- scanning.With the development and completion of radiation treatment

edema in local parts disappeared and the affected range of tumor reduced gradually; meanwhil e

fibrosis in local parts em erged and increased.After six-month therapy

edema in local parts decreased by the rate of 92% and tumor by the rate of 88%.Conclusion:Recurre nce of nasopha ryngeal cancer after radiation therapy refers to that the complete disappearance of nasopharyngeal lumps after the treatment

through a period of time (over six months)

on nasopharyngeal parts seemed normal on CT-manifestation

soft tissue lumps reappeared in accordance with changes in the deep structure of nose and throat

even accompanied with damage to lase of skull. Hence

nasopharyngeal cancer sufferers must be watched through CT-observation on regular interval within more th an six months after treatment

so as to be differentiated with edema and fib rosis after therapy.