Trans-arterial Radioembolization Dosimetry in 2022

Area of Science:

• Nuclear medicine
• Interventional radiology
• Oncology

Background:

• Trans-arterial radioembolization (TARE) uses yttrium-90 (⁹⁰Y) or holmium-166 (¹⁶⁶Ho) microspheres.
• Different microsphere types and isotopes have varying radiobiology, impacting effective tumoricidal doses.

Purpose of the Study:

• To review dosimetry and radiobiology concepts for TARE.
• To present dosimetry approaches, confounding factors, and clinical results over the past decade.
• To highlight the impact of personalized dosimetry on treatment outcomes.

Main Methods:

• Review of simulation-based and post-treatment dosimetry approaches.
• Analysis of clinical dosimetry results for hepatocellular carcinoma (HCC) and metastatic colorectal carcinoma (mCRC).
• Evaluation of tumoricidal and maximal tolerated doses for different TARE agents.

Main Results:

• Tumoricidal doses vary: 100-120 Gy (⁹⁰Y resin), 205 Gy (⁹⁰Y glass) for HCC; 39-60 Gy (⁹⁰Y resin), 139 Gy (⁹⁰Y glass), 90 Gy (¹⁶⁶Ho) for mCRC.
• Tumor dose correlates with overall survival.
• Personalized dosimetry is increasingly recommended and supported by level-one evidence for HCC.

Conclusions:

• Personalized dosimetry is crucial for optimizing TARE efficacy.
• Evidence supports personalized dosimetry as a new standard for TARE in HCC.
• This approach impacts clinical practice, trial design, and patient survival.