Assessing therapeutic response to Radium-223

Area of Science:

• Oncology
• Radiopharmaceutical Therapy
• Biomarker Discovery

Background:

• Radium-223 (223Ra) is an alpha-emitting radiopharmaceutical improving overall survival (OS) and reducing skeletal-related events (SREs) in metastatic castration-resistant prostate cancer (mCRPC).
• Assessing 223Ra therapeutic response is challenging due to its unique mechanism affecting bone remodeling and the tumor microenvironment.
• Conventional serum tumor biomarkers (e.g., PSA, ALP) are insufficient for comprehensive response evaluation.

Purpose of the Study:

• To review and integrate current and emerging strategies for evaluating 223Ra treatment response in mCRPC.
• To highlight the necessity of a multimodal approach combining various assessment tools beyond traditional biomarkers.

Main Methods:

• Review of classic serum biomarkers (PSA, ALP) for prognostic and monitoring roles.
• Examination of emerging liquid biopsy tools: circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), bone metabolism markers, and exosomes.
• Exploration of imaging biomarkers: 18F-fluoride PET/CT, whole-body diffusion-weighted MRI, PSMA PET/CT, and RECIST criteria.
• Inclusion of innovative technologies: radiomics and artificial intelligence (AI) for data integration and outcome prediction.

Main Results:

• Classic biomarkers offer prognostic and monitoring insights but are limited in comprehensively assessing 223Ra response.
• Liquid biopsy tools show potential in reflecting metabolic changes induced by 223Ra therapy.
• Imaging biomarkers are central to response assessment, with ongoing advancements and limitations.
• Radiomics and AI can integrate diverse data (clinical, molecular, imaging) to enhance outcome prediction and personalize care.

Conclusions:

• A multimodal strategy integrating biological markers (serum, liquid biopsy) and advanced imaging is crucial for accurate 223Ra response evaluation.
• Innovative analytical methods like radiomics and AI can significantly improve outcome prediction and treatment personalization.
• Enhanced response assessment through a multimodal approach is expected to lead to improved clinical outcomes for mCRPC patients treated with 223Ra.