Seminario de Física Médica
Title: 4D tool to estimate the dose to the peripheral blood during radiation therapy
Author: Abdelkhalek Hammi, PhD
Affiliation: TU Dortmund
Purpose: To develop a computational model to calculate the accumulated dose to circulating blood for a variety of radiation treatment modalities.
Materials and Methods: To describe the 4D propagation of blood particles through organs and radiation fields, a whole- body blood flow model has been developed, based on volumetric and regional hemodynamics references. A blood flow optimizer has been developed that can produce patient specific calibration to adapt the averaged references to patient specific blood transition probability. The temporal distribution of blood across the entire body is simulated using a mixed model of queuing approach and limited discrete-time Markov process.
For head-and-neck patients, an automated gray-scale boundary-based corner detector has been developed that can extracts the large-scale architecture of cerebral arteries from MRA data. To investigate the impact of treatment modalities, three different radiation techniques were implemented: proton pencil beam scanning (PBS) and proton passive scattering (PS) as well as photon therapy.
Results: Protons-based treatment reduced the mean dose to the circulating blood by 52% compared to photon therapy. The fraction of blood volume receiving any dose V 0Gy after a single radiation fraction increases from 2.2% for PBS to 5.7% and 19.1% for PS and photon therapy, respectively. These values were found to depend on the applied dose rate for photon therapy but less for PBS.
Conclusion: This framework estimates patient-specific dose to circulating blood based on patient optimized regional blood flow rates and more realistic vasculature network and enables us to study the impact of different treatment techniques, dose rates and fractionations.
Online link: https://conectaha.csic.es/b/fer-gny-a0x-omp. The room access code will be sent per e-mail.
Ana Ros y Fernando Hueso