Heterogeneous effects of fulvestrant were observed between lesions within individuals. Heterogeneous effects of fulvestrant were observed between lesions within individuals. In this patient, spinal bone metastases showed >90% reduction in FES uptake (arrows), whereas the right femoral lesion had <50% decrease (arrowhead). Physiologic tracer distribution was observed in liver, intestines, bladder, and at the injection site. Michel van Kruchten et al. Cancer Discovery 2015;5:72-81 ©2015 by American Association for Cancer Research