Bone Imaging in Metastatic Castration-resistant Prostate Cancer; Where do we Stand

Background and Objectives: We are witnessing an era of increased clinical interest in metastatic castration-resistant prostate cancer, both in terms of treatment and also in terms of imaging options. This surge of interest is attributed to the recent developments in treatments for metastatic prostate cancer that are able to confer a significant survival advantage. We are therefore, anticipating an increase in the number of patients that we need to treat at this disease stage. Imaging is undoubtedly crucial in monitoring disease response to treatment and progression. Methods: We have reviewed the recent literature using the following search terms: “metastatic prostate cancer”, “castration-resistant”, “bone metastases”, “bone scan”, “abiraterone”, “enzalutamide”. Results: Bone scintigraphy has evolved recently with new and more sensitive tracers that can accurately diagnose even low volume disease progression. MRI has an established role in the diagnosis of spinal cord compression. Conclusion: Metastatic, castration-resistant prostate cancer is a discrete and different phase of prostate cancer with newer agents that have shown great promise in controlling the disease and offering a survival benefit for patients. Recommendations regarding the choice of imaging, trigger points for repeating imaging and intervals between imaging are still under development for this phase of the disease especially for patients treated with new androgen targeted agents.