We compared the results of early follow-up of F-18 FDG PET/CT and MRI performed within one month after radiation therapy for cervix cancer patients. We conducted a retrospective review of the clinical data of cervix cancer patients whose PET/CT and pelvic MRI performed at staging and within one month from the end of RTx. SUVmax on PET/CT and size on MRI of the primary tumor were analyzed. We compared %change of SUVmax and size between staging and follow-up. A total of 27 patients were enrolled. At staging, larger tumor showed high SUVmax. At follow-up, no significant correlation was observed between size and SUVmax. In 77.8% of patients, changes in SUVmax were well correlated with changes in size. No correlation was observed between % change and value at staging in both SUVmax and size. Except for six patients who showed significant FDG uptake without evidence of a mass on MRI, % changes of size and SUVmax were well correlated. Metabolic change can be accessible on early follow-up PET/CT at±1 month from the end of the RTx of cervix cancer. However, careful interpretation of PET/CT is needed due to possible radiation-induced hypermetabolism even without a definite mass on MRI.

• Ari Chong(Department of Nuclear Medicine, Chosun University Hospital)
• Jung-Min Ha(Department of Nuclear Medicine, Chosun University Hospital)
• Ho-Chun Song(Department of Nuclear Medicine, Chonam University Hospital)
• Min-Young Jung(Department of Radiology, Chonam University Hospital)
• Young Cheol Kim(Department of Nuclear Medicine, Chosun University Hospital) Corresponding author