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Monte Carlo simulation study to explore optimum conditions for Astatine-211 SPECT
Akihiko Takahashi1, Ryosuke Kajiya2, Shingo Baba3
1Division of Medical Quantum Science, Department of Health Sciences, Kyushu University, Maidashi 3-1-1, Higashi-Ku, Fukuoka, Japan. takahashi.akihiko.186@m.kyushu-u.ac.jp.
Radiological Physics and Technology
|January 31, 2023
Summary
Astatine-211 (At-211) SPECT imaging is feasible for targeted therapy evaluation. Low-energy collimators and scatter correction optimize image quality for detecting lesions larger than 20 mm.
Area of Science:
- Nuclear Medicine
- Medical Imaging
- Radiopharmaceutical Therapy
Background:
- Astatine-211 (At-211) is a promising radionuclide for targeted radioisotope therapy.
- Direct in vivo imaging is crucial for evaluating At-211 distribution and treatment efficacy.
Purpose of the Study:
- To investigate optimal conditions for single-photon emission computed tomography (SPECT) imaging of At-211.
- To assess the feasibility of At-211 SPECT using Monte Carlo simulations and phantom studies.
Main Methods:
- Simulated SPECT imaging of At-211 using a homemade Monte Carlo code (MCEP-SPECT).
- Evaluated four collimator types (medium- and low-energy) with varying sensitivity and resolution.
- Utilized ordered subset expectation maximization (OSEM) reconstruction with attenuation and scatter correction.
Main Results:
- Low-energy, high-sensitivity collimators provided the best detectability (CNR up to 43).
- Low-energy, high-resolution collimators offered superior quantitation (CRC up to 102%).
- Scatter correction significantly improved image quality, nearly doubling CRC values.
Conclusions:
- Low-energy collimators are suitable for At-211 SPECT imaging.
- Scatter correction is highly effective in enhancing image quality for At-211.
- At-211 SPECT is feasible for imaging lesions exceeding 20 mm in diameter.
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