Monte Carlo MCNP-4B–Based Absorbed Dose Distribution Estimates for Patient-Specific Dosimetry

Journal of Nuclear Medicine

Adimir dos Santos¹  Hélio Yoriyaz¹  Michael G. Stabin¹ 

[1] Instituto de Pesquisas Energéticas e Nucleares, Cidade Universitária, São Paulo; and Universidade Federal de Pernambuco, Recife, Brazil Instituto de Pesquisas Energéticas e Nucleares, Cidade Universitária, São Paulo; and Universidade Federal de Pernambuco, Recife, Brazil Instituto de Pesquisas Energéticas e Nucleares, Cidade Universitária, São Paulo; and Universidade Federal de Pernambuco, Recife, Brazil

关键词: radioimmunotherapy;    patient-specific dosimetry;    Monte Carlo simulation;    electrons and photons;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

This study was intended to verify the capability of the Monte Carlo MCNP-4B code to evaluate spatial dose distribution based on information gathered from CT or SPECT. Methods: A new three-dimensional (3D) dose calculation approach for internal emitter use in radioimmunotherapy (RIT) was developed using the Monte Carlo MCNP-4B code as the photon and electron transport engine. It was shown that the MCNP-4B computer code can be used with voxel-based anatomic and physiologic data to provide 3D dose distributions. Results: This study showed that the MCNP-4B code can be used to develop a treatment planning system that will provide such information in a time manner, if dose reporting is suitably optimized. If each organ is divided into small regions where the average energy deposition is calculated with a typical volume of 0.4 cm3, regional dose distributions can be provided with reasonable central processing unit times (on the order of 12–24 h on a 200-MHz personal computer or modest workstation). Further efforts to provide semiautomated region identification (segmentation) and improvement of marrow dose calculations are needed to supply a complete system for RIT. It is envisioned that all such efforts will continue to develop and that internal dose calculations may soon be brought to a similar level of accuracy, detail, and robustness as is commonly expected in external dose treatment planning. Conclusion: For this study we developed a code with a user-friendly interface that works on several nuclear medicine imaging platforms and provides timely patient-specific dose information to the physician and medical physicist. Future therapy with internal emitters should use a 3D dose calculation approach, which represents a significant advance over dose information provided by the standard geometric phantoms used for more than 20 y (which permit reporting of only average organ doses for certain standardized individuals)

【 授权许可】

Unknown