Comparison of positron emission tomography/CT and bremsstrahlung imaging following Y-90 radiation synovectomy

J Med Imaging Radiat Oncol. 2013 Oct;57(5):567-71. doi: 10.1111/1754-9485.12049. Epub 2013 Mar 26.

Abstract

Introduction: The aim of this study is to compare the results of positron emission tomography (PET)/CT with bremsstrahlung imaging following Y-90 radiation synovectomy.

Methods: All patients referred to our institution for Y-90 radiation synovectomy between July 2011 and February 2012 underwent both PET/CT and bremsstrahlung planar (± single photon emission computed tomography (SPECT) or SPECT/CT) imaging at 4 or 24 h following administration of Y-90 silicate colloid. PET image acquisition was performed for between 15 and 20 min. In patients who underwent SPECT, side-by-side comparison with PET was performed and image quality/resolution scored using a five-point scale. The distribution pattern of Y-90 on PET and bremsstrahlung imaging was compared with the intra- or extra-articular location of Y-90 activity on fused PET/CT.

Results: Thirteen joints (11 knees and two ankles) were imaged with both PET/CT and planar bremsstrahlung imaging with 12 joints also imaged with bremsstrahlung SPECT. Of the 12 joints imaged with SPECT, PET image quality/resolution was superior in 11 and inferior in one. PET demonstrated a concordant distribution pattern compared with bremsstrahlung imaging in all scans, with the pattern classified as diffuse in 12 and predominantly focal in one. In all 12 diffuse scans, PET/CT confirmed the Y-90 activity to be located intra-articularly. In the one predominantly focal scan, the fused PET/CT images localised the Y-90 activity to mostly lie in the extra-articular space of the knee.

Conclusion: PET/CT can provide superior image quality compared with bremsstrahlung imaging and may enable reliable detection of extra-articular Y-90 activity when there are focal patterns on planar bremsstrahlung imaging.

Keywords: PET; PET/CT; bremsstrahlung; yttrium radiation synovectomy.

Publication types

  • Comparative Study
  • Controlled Clinical Trial

MeSH terms

  • Female
  • Humans
  • Male
  • Multimodal Imaging / methods*
  • Positron-Emission Tomography / methods*
  • Radiopharmaceuticals / therapeutic use
  • Radiotherapy, Image-Guided / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Synovitis / diagnosis*
  • Synovitis / radiotherapy*
  • Tomography, X-Ray Computed / methods*
  • Treatment Outcome
  • Yttrium Radioisotopes / therapeutic use*

Substances

  • Radiopharmaceuticals
  • Yttrium Radioisotopes