PURPOSE: To calculate the dose in time-dependent geometry, the results of three-dimensional calculations are usually performed separately and combined. This approach becomes cumbersome when high temporal resolution is required, if the geometry is complex, or if interplay effects between different, independently moving systems are to be studied. The purpose of this project was the implementation of continuous (four-dimensional [4D]) Monte Carlo simulation to study the irradiation of tumors under respiratory motion. METHODS AND MATERIALS: In taking advantage of object-oriented programming, we implemented 4D Monte Carlo dose calculation. Local dose depositions in the patient are calculated while beam configuration and organ positions are changed continuously. Deformable image registration is used to describe the CT voxel displacement over time. RESULTS: The 4D Monte Carlo technique is applied to a lung cancer case planned for proton therapy. We show that the effect of motion on the dose distribution can be simulated effectively based on statistical motion parameterizations acting on the geometry or based on patient-specific 4D CT information. CONCLUSION: We present a novel method able to calculate dose with underlying time-dependent geometry. The technique allows 4D dose calculation in arbitrary time scales in a single simulation even for double-dynamic systems (e.g., time-dependent beam delivery under organ motion).
PURPOSE: To calculate the dose in time-dependent geometry, the results of three-dimensional calculations are usually performed separately and combined. This approach becomes cumbersome when high temporal resolution is required, if the geometry is complex, or if interplay effects between different, independently moving systems are to be studied. The purpose of this project was the implementation of continuous (four-dimensional [4D]) Monte Carlo simulation to study the irradiation of tumors under respiratory motion. METHODS AND MATERIALS: In taking advantage of object-oriented programming, we implemented 4D Monte Carlo dose calculation. Local dose depositions in the patient are calculated while beam configuration and organ positions are changed continuously. Deformable image registration is used to describe the CT voxel displacement over time. RESULTS: The 4D Monte Carlo technique is applied to a lung cancer case planned for proton therapy. We show that the effect of motion on the dose distribution can be simulated effectively based on statistical motion parameterizations acting on the geometry or based on patient-specific 4D CT information. CONCLUSION: We present a novel method able to calculate dose with underlying time-dependent geometry. The technique allows 4D dose calculation in arbitrary time scales in a single simulation even for double-dynamic systems (e.g., time-dependent beam delivery under organ motion).
Authors: Tianfang Li; Zhengrong Liang; Jayalakshmi V Singanallur; Todd J Satogata; David C Williams; Reinhard W Schulte Journal: Med Phys Date: 2006-03 Impact factor: 4.071
Authors: Ross McGurk; Joao Seco; Marco Riboldi; John Wolfgang; Paul Segars; Harald Paganetti Journal: Phys Med Biol Date: 2010-02-16 Impact factor: 3.609
Authors: Alfredo E Echeverria; Matthew McCurdy; Richard Castillo; Vincent Bernard; Natalia Velez Ramos; William Buckley; Edward Castillo; Ping Liu; Josue Martinez; Thomas Guerrero Journal: Radiother Oncol Date: 2012-11-02 Impact factor: 6.280
Authors: James E Younkin; Danairis Hernandez Morales; Jiajian Shen; Xiaoning Ding; Joshua B Stoker; Nathan Y Yu; Terence T Sio; Thomas B Daniels; Martin Bues; Mirek Fatyga; Steven E Schild; Wei Liu Journal: Med Phys Date: 2021-07-29 Impact factor: 4.506