Technical note: MC-GPU breast dosimetry validations with other Monte Carlo codes and phase space file implementation

Autor(es)

Massera, Rodrigo T. ^{[1, 2]} ; Thomson, Rowan M. ^[2] ; Tomal, Alessandra ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil

^[2] Carleton Univ, Dept Phys, Carleton Lab Radiotherapy Phys, Ottawa, ON - Canada

• Tipo de documento: Artigo Científico
• Fonte: Medical Physics; v. 49, n. 1 NOV 2021.
• Citações Web of Science: 0

Resumo

Purpose To validate the MC-GPU Monte Carlo (MC) code for dosimetric studies in X-ray breast imaging modalities: mammography, digital breast tomosynthesis, contrast enhanced digital mammography, and breast-CT. Moreover, to implement and validate a phase space file generation routine. Methods The MC-GPU code (v. 1.5 DBT) was modified in order to generate phase space files and to be compatible with PENELOPE v. 2018 derived cross-section database. Simulations were performed with homogeneous and anthropomorphic breast phantoms for different breast imaging techniques. The glandular dose was computed for each case and compared with results from the PENELOPE (v. 2014) + penEasy (v. 2015) and egs\_brachy (EGSnrc) MC codes. Afterward, several phase space files were generated with MC-GPU and the scored photon spectra were compared between the codes. The phase space files generated in MC-GPU were used in PENELOPE and EGSnrc to calculate the glandular dose, and compared with the original dose scored in MC-GPU. Results MC-GPU showed good agreement with the other codes when calculating the glandular dose distribution for mammography, mean glandular dose for digital breast tomosynthesis, and normalized glandular dose for breast-CT. The latter case showed average/maximum relative differences of 2.3%/27%, respectively, compared to other literature works, with the larger differences observed at low energies (around 10 keV). The recorded photon spectra entering a voxel were similar (within statistical uncertainties) between the three MC codes. Finally, the reconstructed glandular dose in a voxel from a phase space file differs by less than 0.65%, with an average of 0.18%-0.22% between the different MC codes, agreement within approximately 2 sigma statistical uncertainties. In some scenarios, the simulations performed in MC-GPU were from 20 up to 40 times faster than those performed by PENELOPE. Conclusions The results indicate that MC-GPU code is suitable for breast dosimetric studies for different X-ray breast imaging modalities, with the advantage of a high performance derived from GPUs. The phase space file implementation was validated and is compatible with the IAEA standard, allowing multiscale MC simulations with a combination of CPU and GPU codes. (AU)

• Processo FAPESP: 18/05982-0 - P&D&I em metrologia das radiações na área da saúde
• Beneficiário: Linda Viola Ehlin Caldas
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 15/21873-8 - Desenvolvimento e implementação de metodologias para otimização de técnicas de imagens em radiologia digital
• Beneficiário: Alessandra Tomal
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/15366-9 - Otimização dos parâmetros de exposição em mamografia digital: estudos experimentais e por Simulação Monte Carlo
• Beneficiário: Rodrigo Trevisan Massera
• Modalidade de apoio: Bolsas no Brasil - Mestrado