RT Journal Article SR Electronic T1 90Y PET for Qualitative and Quantitative Assessment of Residual Activity in Delivery Apparatus After Radioembolization JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 178 OP 179 DO 10.2967/jnmt.120.258251 VO 49 IS 2 A1 Yung Hsiang Kao A1 Alicia Corlett A1 Katrina Jorna A1 Alexander Rhodes A1 Dinesh Sivaratnam YR 2021 UL http://tech.snmjournals.org/content/49/2/178.abstract AB Assessment of residual activity is critical for quality assurance after 90Y radioembolization. The resin microsphere manufacturer’s indirect method of estimating the residual activity is laborious and vulnerable to inaccuracies. Furthermore, the method cannot localize the exact site of residual activity. 90Y PET/CT for qualitative and quantitative assessment of residual activity has not, to our knowledge, been described. We show an example of 90Y 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%.