Current Status of Radiopharmaceutical Therapy

Area of Science:

• Oncology
• Nuclear Medicine
• Medical Physics

Background:

• Radiopharmaceutical therapy (RPT) uses radionuclides to target cancer cells.
• Current RPTs include treatments for thyroid, liver, bone metastases, and neuroendocrine tumors.
• RPT administration and treatment planning are often based on fixed doses or patient metrics like body weight, similar to chemotherapy.

Purpose of the Study:

• To highlight the need for advanced quantitative imaging and dosimetry methods in RPT.
• To address the limitations of current fixed or weight-based RPT activity prescriptions.
• To emphasize the importance of patient-specific dosimetry for optimizing RPT efficacy and safety.

Main Methods:

• Discussing dosimetric accuracy needs in modern radiation oncology.
• Identifying uncertainties in current RPT dosimetry.
• Exploring best approaches for imaging and dosimetry in internal radionuclide therapy.

Main Results:

• RPT pharmacokinetics vary significantly between patients in both tumors and normal tissues.
• Fixed or weight-based activity prescriptions are suboptimal for delivering targeted cytotoxic doses and respecting organ tolerance.
• Quantitative imaging enables measurement of activity distribution in vivo for patient-specific dose calculations.

Conclusions:

• Patient-specific, imaging-based dosimetry is essential for accurate dose delivery in RPT.
• Accurate dosimetry improves treatment outcomes for individual patients and reduces uncertainties in clinical trials.
• Adoption of imaging-based dosimetry methods is particularly beneficial for early-phase RPT clinical trials.