FDG PET/CT is useful for the early evaluation of response to therapy in patients affected by diskitis

Objectives Aim was to assess the possible role of FDG PET-CT for the early evaluation of the response to therapy in patients affected by infective diskitis.

Methods 12 pts(4F,8M; mean age 68yo, range 31-85) with infective diskitis were enrolled. 2had a proved tubercular infection, 3 had a pyogenic diskitis and 7 were diagnosed on the basis of MR, symptoms, inflammatory indexes and risk factors (non-diagnostic cultural exam). All the patients underwent a baseline FDG PET-CT and a second exam 2to4 wks after the therapy onset. Non responder patients at PET underwent a change in therapy and repeated the scan 2to4 wks after the new therapy onset. The PET results were compared to MR, inflammatory indexes and clinical status during the follow up (mean 6months).

Results Mean SUVmax at diagnosis was 7.3(min 4.1; max 12.3). 9 pts showed a significant reduction in SUVmax while 3 were non responder(SUVmax stable or increased). After change in therapy, all non responder patients showed a significant decrease in SUVmax, comparable with responders(Tab1). All the pts showed a persistent clinical complete response at follow-up.

Conclusions Our preliminary results indicate that FDG PET-CT is able to show an early response to therapy in patients affected by diskitis, anticipating a clinical complete response. This may help the clinician to guide the antibiotic therapy,especially in case of an empiric line and in case of negative inflammatory indexes at diagnosis

• Download figure
• Open in new tab
• Download powerpoint

SUV max before therapy and during therapy in responder and non responder patients