The radiation therapy is applied on around 50% of the cancer patients. As we know, before implementing a radiation treatment planning system in the clinic, the dose-calculation measurement must be validated using rigo...The radiation therapy is applied on around 50% of the cancer patients. As we know, before implementing a radiation treatment planning system in the clinic, the dose-calculation measurement must be validated using rigorous, clinically relevant criteria [1]. Percent Depth Doses (PDD), Dose Profile (DP), Open Collimator Factor (OCF) etc., are measured for all numbers of square fields for Treatment Planning System XiO, version 4.7, for 6 and 15 MV photons energies and for 15°, 30°, 45°, 60° wedge, which were employed to obtain the profiles in any depth. The measurements were conducted also for different energies of electron beam and TPS calculation algorithms.展开更多
The study is aimed to investigate the effect of the trace element concentrations in healthy and cancerous prostate tissues on dose distributions in radiotherapy. In this work, the trace element compounds completely so...The study is aimed to investigate the effect of the trace element concentrations in healthy and cancerous prostate tissues on dose distributions in radiotherapy. In this work, the trace element compounds completely soluble in the water were used and their concentrations given in the literature were mixed homogeneously with pure water. This is the first time study in literature as far as we know. The percent depth dose (PDD) measurements were performed using Elekta Synergy Platform Linac device for 6 and 18 MV photon energies. We also obtained the PDDs results by choosing higher trace element concentrations than given in literature in cancerous prostate tissue to see the effect on radiotherapy. The experimental measurements were compared with the results obtained from the GATE simulation code. The TPR<sub>20/10</sub> was calculated for 10 × 10 cm<sup>2</sup> field size at 6/18 MV energies photons and compared with simulation results. The differences between simulation and measurement for 6 MV and 18 MV photons are 1.75% and 1.82% respectively. The experimental results and simulations were presented an uncertainty lower than 3%. Simulated dose values are in good agreement with less than 2% differences with the experimental results. We see that the trace element concentrations of healthy and cancerous tissues did not affect the dose distribution at high-energy photons. This is expected and well known result. We believe that this <em>in vitro</em> study is important for proving the reliability of the dose given in radiotherapy treatment once again.展开更多
In this paper,the beam quality and percent depth dose curves for different field sizes of CyberKnife? system were investigated by Monte Carlo simulations using the PENELOPE code,which has been used to simulate 6 MV ph...In this paper,the beam quality and percent depth dose curves for different field sizes of CyberKnife? system were investigated by Monte Carlo simulations using the PENELOPE code,which has been used to simulate 6 MV photon beam.In water phantom,the absolute doses were calculated for Φ10–60 mm collimators,and percent depth dose curves were evaluated for Φ30–60 mm collimators.The agreement of dose distributions of the calculation with measurement was within 3.0%.The mean energy of photon spectrum was 1.46 MeV,and the beam quality index was 0.632,which was slightly smaller than that of measurement.展开更多
In this paper,we have addressed the problem of the radiation transport with the Monte Carlo N-particle(MCNP) code.This is a general-purpose Monte Carlo tool designed to transport neutron,photon and electron in three d...In this paper,we have addressed the problem of the radiation transport with the Monte Carlo N-particle(MCNP) code.This is a general-purpose Monte Carlo tool designed to transport neutron,photon and electron in three dimensional geometries.To examine the performance of MCNP5 code in the field of external radiotherapy,we performed the modeling of an Electron Density phantom(EDP) irradiated by photons from 60Co source.The model was used to calculate the Percent Depth Dose(PDD) at different depths in an EDP.One field size for PDD has been examined.A 60Co photons source placed at 80 cm source to surface distance(SSD).The results of calculations were compared to TPS data obtained at National Institute of Oncology of Rabat.展开更多
文摘The radiation therapy is applied on around 50% of the cancer patients. As we know, before implementing a radiation treatment planning system in the clinic, the dose-calculation measurement must be validated using rigorous, clinically relevant criteria [1]. Percent Depth Doses (PDD), Dose Profile (DP), Open Collimator Factor (OCF) etc., are measured for all numbers of square fields for Treatment Planning System XiO, version 4.7, for 6 and 15 MV photons energies and for 15°, 30°, 45°, 60° wedge, which were employed to obtain the profiles in any depth. The measurements were conducted also for different energies of electron beam and TPS calculation algorithms.
文摘The study is aimed to investigate the effect of the trace element concentrations in healthy and cancerous prostate tissues on dose distributions in radiotherapy. In this work, the trace element compounds completely soluble in the water were used and their concentrations given in the literature were mixed homogeneously with pure water. This is the first time study in literature as far as we know. The percent depth dose (PDD) measurements were performed using Elekta Synergy Platform Linac device for 6 and 18 MV photon energies. We also obtained the PDDs results by choosing higher trace element concentrations than given in literature in cancerous prostate tissue to see the effect on radiotherapy. The experimental measurements were compared with the results obtained from the GATE simulation code. The TPR<sub>20/10</sub> was calculated for 10 × 10 cm<sup>2</sup> field size at 6/18 MV energies photons and compared with simulation results. The differences between simulation and measurement for 6 MV and 18 MV photons are 1.75% and 1.82% respectively. The experimental results and simulations were presented an uncertainty lower than 3%. Simulated dose values are in good agreement with less than 2% differences with the experimental results. We see that the trace element concentrations of healthy and cancerous tissues did not affect the dose distribution at high-energy photons. This is expected and well known result. We believe that this <em>in vitro</em> study is important for proving the reliability of the dose given in radiotherapy treatment once again.
基金Supported by Shanghai Science and Technology Committee (08JC1410200)Shanghai Leading Academic Disciplines (S30109)
文摘In this paper,the beam quality and percent depth dose curves for different field sizes of CyberKnife? system were investigated by Monte Carlo simulations using the PENELOPE code,which has been used to simulate 6 MV photon beam.In water phantom,the absolute doses were calculated for Φ10–60 mm collimators,and percent depth dose curves were evaluated for Φ30–60 mm collimators.The agreement of dose distributions of the calculation with measurement was within 3.0%.The mean energy of photon spectrum was 1.46 MeV,and the beam quality index was 0.632,which was slightly smaller than that of measurement.
基金Laboratory of Radiation and Nuclear Systems (LRSN)
文摘In this paper,we have addressed the problem of the radiation transport with the Monte Carlo N-particle(MCNP) code.This is a general-purpose Monte Carlo tool designed to transport neutron,photon and electron in three dimensional geometries.To examine the performance of MCNP5 code in the field of external radiotherapy,we performed the modeling of an Electron Density phantom(EDP) irradiated by photons from 60Co source.The model was used to calculate the Percent Depth Dose(PDD) at different depths in an EDP.One field size for PDD has been examined.A 60Co photons source placed at 80 cm source to surface distance(SSD).The results of calculations were compared to TPS data obtained at National Institute of Oncology of Rabat.
