**5. Conclusions**

In this patient cohort that presented for restaging, we found that a high MTV and TLG of the primary tumor and whole-body TLG were prognostic for overall survival. These findings may assist clinicians in evaluating and recognizing patients with a poorer prognosis in a similar population group.

**Author Contributions:** Conceptualization: K.N.H., K.M.G.M., M.V. and M.M.S.; data curation: K.N.H., K.M.G.M., Z.M.-Z., M.V. and M.M.S.; methodology, K.N.H., K.M.G.M., M.V., Z.M.-Z. and M.M.S.; software: K.N.H., K.M.G.M. and M.M.S.; formal analysis: K.N.H., K.M.G.M., Z.M.-Z., M.V. and M.M.S.; validation: K.N.H., K.M.G.M., Z.M.-Z. and M.M.S.; investigation: K.N.H., K.M.G.M., Z.M.-Z., M.V. and M.M.S.; writing—original draft preparation: K.N.H., K.M.G.M., Z.M.-Z., M.V. and M.M.S.; writing—review and editing: K.N.H., K.M.G.M., Z.M.-Z. and M.M.S.; supervision: K.M.G.M., M.V. and M.M.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and approved by the Research Ethics Committee, University of Pretoria (protocol code 875/2020 on 21 January 2021).

**Informed Consent Statement:** Patient consent was waived due to the retrospective nature of the study, as granted by the Research Ethics Committee.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data is not publicly available due to patient confidentiality.

**Acknowledgments:** The authors wish to acknowledge Susan Botha (Medical Oncology) and Frans Mothapo (Nuclear Medicine) for the many hours spent accessing clinical records for data collection.

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