**5. Conclusions**

Results from anthropomorphic phantom studies sugges<sup>t</sup> that post-therapy SIRT PET-CT imaging is improved by quiescent period respiratory motion correction. Specifically, improved accuracy of tumour quantification and dosimetric measures are predicted.

**Author Contributions:** Conceptualization, M.D.W. and D.R.M.; methodology, M.D.W. and D.R.M.; investigation, M.D.W., J.I.G. and A.J.C.; writing—original draft preparation, M.D.W.; writing—review and editing, M.D.W., J.I.G., A.J.C. and D.R.M.; funding acquisition, D.R.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding. The APC was funded by Oxford University Hospitals NHS Foundation Trust.

**Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Acknowledgments:** The radionuclides used for this research were provided by Sirtex, and the Abdo-man phantom was loaned from the Royal Marsden NHS Foundation Trust and Institute of Cancer Research.

**Conflicts of Interest:** The authors declare no conflict of interest.
