[Validation of Quantitative Accuracy and Variability in ¹⁷⁷Lu Imaging Using Monte Carlo Simulation]

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiopharmaceutical Dosimetry

Background:

• Accurate quantitative SPECT imaging is essential for 177Lu dosimetry.
• Predicting side effects and optimizing doses require precise quantitative values.

Purpose of the Study:

• To verify the accuracy and variability of quantitative SPECT imaging for 177Lu.
• To evaluate different imaging conditions for optimizing 177Lu dosimetry.

Main Methods:

• Monte Carlo simulations using the SIMIND program.
• Simulated 177Lu-Dotatate SPECT data from a NEMA body phantom with intrahepatic tumors.
• Varied collimators, energy windows, and acquisition times; assessed accuracy via relative error and variability via coefficient of variation.

Main Results:

• Background quantification accuracy was within 10% relative error.
• Hot sphere quantification accuracy was highest with MEGP collimator and 208 keV ±10% energy window.
• Accuracy decreased with smaller hot sphere diameters; variability improved with longer acquisition times.

Conclusions:

• Monte Carlo simulations provide insights into SPECT imaging accuracy and variability for 177Lu.
• Identified optimal imaging parameters for enhancing quantitative accuracy in 177Lu SPECT.