Yttrium-90 positron emission tomography for qualitative and quantitative assessment of residual activity in delivery apparatus after radioembolization

Abstract

Assessment of residual activity is critical for quality assurance after yttrium-90 radioembolization. The resin microsphere manufacturer’s indirect method of estimating the residual activity is laborious and vulnerable to inaccuracies. Furthermore, their method cannot localize the exact site of residual activity. Yttrium-90 PET/CT for qualitative and quantitative assessment of residual activity has not been described. We show an example of yttrium-90 PET/CT of residual activity in the delivery apparatus and catheters packed inside the delivery box. Focally intense residual activity was clearly localized to the stopcock junction. Residual activity was directly quantified by setting the PET volume-of-interest isocontour threshold to 1%.