Methodology for radionuclides quantification through "in vitro" bioassay

Area of Science:

• Nuclear Medicine
• Radiopharmacology
• Radiation Protection

Background:

• Radionuclide therapy utilizes isotopes like Iodine-131, Samarium-153, Yttrium-90, and Lutetium-177 in Brazil.
• Bioassay analysis of excreted radionuclides is crucial for individualized treatment planning in nuclear medicine.

Purpose of the Study:

• To detail the methodology and quality assurance of bioassay analysis for excreted radionuclides at the Bioassay Laboratory (LBIOVT).
• To highlight the importance of accurate radionuclide quantification for patient safety and effective therapy.

Main Methods:

• Utilizing gamma and beta spectroscopy calibrated with National Laboratory of Radiation Metrology (LMNRI/IRD) reference sources.
• Adhering to ISO-ABNT-17025 standards for operational procedures and participating in intercomparisons.
• Collecting, handling, storing, and transporting patient excreta samples according to national radiation protection regulations.

Main Results:

• The LBIOVT is equipped for precise radionuclide activity measurement in patient samples.
• Accreditation and intercomparison participation ensure reliable results for radionuclide specific activity (Bq/L).
• Careful manipulation of excreta volumes prevents quantification errors and supports biological half-life estimation.

Conclusions:

• The LBIOVT's robust bioassay procedures provide reliable radionuclide quantification.
• Accreditation and quality control measures enhance confidence in patient monitoring and minimize uncertainties.
• Accurate bioassay is essential for optimizing radionuclide therapy and ensuring patient safety.