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

• Published in: Journal of medical imaging and radiation oncology Vol. 57; no. 5; pp. 567 - 571
• Main Authors: Barber, Thomas W., Yap, Kenneth S. K., Cherk, Martin H., Powell, Anne, Kalff, Victor
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01.10.2013; Wiley Subscription Services, Inc
• Subjects: bremsstrahlung; Female; Humans; Male; Multimodal Imaging - methods; PET; PET/CT; 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 radiation synovectomy; Yttrium Radioisotopes - therapeutic use; bremsstrahlung; yttrium radiation synovectomy; PET; PET/CT
• ISSN: 1754-9477; 1754-9485
• DOI: 10.1111/1754-9485.12049

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.