Title:Final Outcome of 223Ra-therapy and the Role of 18F-fluoride-PET in Response Evaluation in Metastatic Castration-resistant Prostate Cancer–A Single Institution Experience
VOLUME: 11 ISSUE: 2
Author(s):Kalevi Kairemo, Denai R. Milton, Elba Etchebehere, Eric M. Rohren and Homer A. Macapinlac*
Affiliation:Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston
Keywords:Radium-223, sodium fluoride-18, skeletal metastases, prostate cancer, castration resistant, radionuclide therapy,
alpha emitter, response evaluation.
Abstract:Background: 223Ra was the first therapeutic alpha-emitting radionuclide registered for clinical
practice. This radionuclide is targeting actively bone-forming cells, and it is approved for treating
metastatic skeletal disease in prostate cancer. 18F-PET is used to detect skeletal metastatic disease
based on osteoblastic activity. The aim of this study was to analyze, if 18F-PET can be used assessing
the results of 223Ra therapy, and to report final median overall survival in a total of 773 therapy cycles.
Methods: A 161 men with castration-resistant prostate cancer were included in a single institution
study (Protocol#: PA14-0848) and they received a total of 773 223Ra therapy cycles.
Results: The median overall survival (95% CI) was 12.4 (9.1, 16.1) months in patient population.
Interim Na18F-PET imaging was applied in 14 patients at baseline, after 3 cycles and after 6 cycles.
TLF10 (skeletal disease burden at SUV-values >10 on Na18F -PET) were calculated in all these PET
studies, and there was no significant association between change in TLF10 after 3 cycles and TLF10
after 6 cycles (p=0.20).
Conclusion: From these results, we conclude that interim imaging does not help in assessing the final
outcome of 223Ra therapy. The survival benefit of 223Ra therapy alone is more than a year in a high-risk
group of advanced prostate cancer.
