TY - GEN
T1 - Accelerated dose calculation engine for interstitial brachytherapy
AU - Chibani, Omar
AU - Moftah, Belal
AU - Ma, C. M.Charlie
PY - 2009
Y1 - 2009
N2 - Purpose: To present a new accelerated Monte Carlo code (MCPI: Monte Carlo for Prostate Implant) intended for use as a dose calculation engine for planning clinical prostate implants. MCPI simulates physically a set of radioactive seeds with arbitrary positions and orientations, merged in a 3D CT-based heterogeneous phantom representing the prostate and surrounding tissue. Material and Methods: MCPI uses a phase space data source-model to account for seed self-absorption and seed anisotropy. A "hybrid geometry" model (full 3D seed geometry merged in a 3D mesh of voxels) is developed for rigorous treatment of the interseed attenuation effect. MCPI is based upon the GEPTS general-purpose Monte Carlo code. Compton scattering, coherent scattering, and photoelectric effect (with emission of fluorescence X-rays) are modeled in detail, using the XCOM/EPDL97/NIST95 cross-section data. MCPI is benchmarked against the MCNP5 code for the case of an idealized prostate implant, consisting of 83 103Pd (or 125I) seeds. Results: MCNP5 and MCPI are in excellent agreement. The average difference between the dose distributions from the two codes is less than 0.5% for both seed models. For a 2×2×2-mm3 voxel mesh, MCPI calculates the 103Pd and 125I prostate dose distributions with 2% average statistical uncertainty in 23 seconds using a single Intel Core2 processor. More than 30 minutes calculation time is required for MCNP5 to achieve the same statistical precision. MCPI is about 90 and 700 times faster than MCNP5 for 2 and 1-mm3 voxels, respectively. MCPI is used to quantify the effect of calcification on prostate DVH: 5% calcified volume decreases D100 by 58%. Conclusion: The use of multiprocessor parallel calculation can further increase the speed of MCPI and makes quasi-instantaneous dose calculations for prostate implant planning a reality. MCPI can be easily extended to handle other interstitial brachytherapy modalities (e.g. wire sources).
AB - Purpose: To present a new accelerated Monte Carlo code (MCPI: Monte Carlo for Prostate Implant) intended for use as a dose calculation engine for planning clinical prostate implants. MCPI simulates physically a set of radioactive seeds with arbitrary positions and orientations, merged in a 3D CT-based heterogeneous phantom representing the prostate and surrounding tissue. Material and Methods: MCPI uses a phase space data source-model to account for seed self-absorption and seed anisotropy. A "hybrid geometry" model (full 3D seed geometry merged in a 3D mesh of voxels) is developed for rigorous treatment of the interseed attenuation effect. MCPI is based upon the GEPTS general-purpose Monte Carlo code. Compton scattering, coherent scattering, and photoelectric effect (with emission of fluorescence X-rays) are modeled in detail, using the XCOM/EPDL97/NIST95 cross-section data. MCPI is benchmarked against the MCNP5 code for the case of an idealized prostate implant, consisting of 83 103Pd (or 125I) seeds. Results: MCNP5 and MCPI are in excellent agreement. The average difference between the dose distributions from the two codes is less than 0.5% for both seed models. For a 2×2×2-mm3 voxel mesh, MCPI calculates the 103Pd and 125I prostate dose distributions with 2% average statistical uncertainty in 23 seconds using a single Intel Core2 processor. More than 30 minutes calculation time is required for MCNP5 to achieve the same statistical precision. MCPI is about 90 and 700 times faster than MCNP5 for 2 and 1-mm3 voxels, respectively. MCPI is used to quantify the effect of calcification on prostate DVH: 5% calcified volume decreases D100 by 58%. Conclusion: The use of multiprocessor parallel calculation can further increase the speed of MCPI and makes quasi-instantaneous dose calculations for prostate implant planning a reality. MCPI can be easily extended to handle other interstitial brachytherapy modalities (e.g. wire sources).
UR - http://www.scopus.com/inward/record.url?scp=77950441689&partnerID=8YFLogxK
U2 - 10.1007/978-3-642-03474-9_299
DO - 10.1007/978-3-642-03474-9_299
M3 - Conference contribution
AN - SCOPUS:77950441689
SN - 9783642034725
T3 - IFMBE Proceedings
SP - 1063
EP - 1066
BT - World Congress on Medical Physics and Biomedical Engineering
PB - Springer Verlag
T2 - World Congress on Medical Physics and Biomedical Engineering: Radiation Oncology
Y2 - 7 September 2009 through 12 September 2009
ER -