. The Monte Carlo simulation software is a valuable tool in radiation therapy, in particular to achieve the needed accuracy in the dose evaluation for the treatment plans optimisation. The current ...challenge in this field is the time reduction to open the way to many clinical applications for which the computational time is an issue. In this manuscript we present an innovative GPU-accelerated Monte Carlo software for dose valuation in electron and photon based radiotherapy, developed as an update of the FRED (Fast paRticle thErapy Dose evaluator) software.
. The code transports particles through a 3D voxel grid, while scoring their energy deposition along their trajectory. The models of electromagnetic interactions in the energy region between 1 MeV-1 GeV available in literature have been implemented to efficiently run on GPUs, allowing to combine a fast tracking while keeping high accuracy in dose assessment. The FRED software has been bench-marked against state-of-art full MC (FLUKA, GEANT4) in the realm of two different radiotherapy applications: Intra-Operative Radio Therapy and Very High Electron Energy radiotherapy applications.
. The single pencil beam dose-depth profiles in water as well as the dose map computed on non-homogeneous phantom agree with full-MCs at 2% level, observing a gain in processing time from 200 to 5000.
. Such performance allows for computing a plan with electron beams in few minutes with an accuracy of ∼%, demonstrating the FRED potential to be adopted for fast plan re-calculation in photon or electron radiotherapy applications.
Partial breast irradiation for the treatment of early-stage breast cancer patients can be performed by means of Intra Operative electron Radiation Therapy (IOeRT). One of the main limitations of this ...technique is the absence of a treatment planning system (TPS) that could greatly help in ensuring a proper coverage of the target volume during irradiation. An IOeRT TPS has been developed using a fast Monte Carlo (MC) and an ultrasound imaging system to provide the best irradiation strategy (electron beam energy, applicator position and bevel angle) and to facilitate the optimisation of dose prescription and delivery to the target volume while maximising the organs at risk sparing. The study has been performed in silico, exploiting MC simulations of a breast cancer treatment. Ultrasound-based input has been used to compute the absorbed dose maps in different irradiation strategies and a quantitative comparison between the different options was carried out using Dose Volume Histograms.
The system was capable of exploring different beam energies and applicator positions in few minutes, identifying the best strategy with an overall computation time that was found to be completely compatible with clinical implementation. The systematic uncertainty related to tissue deformation during treatment delivery with respect to imaging acquisition was taken into account.
The potential and feasibility of a GPU based full MC TPS implementation of IOeRT breast cancer treatments has been demonstrated in-silico. This long awaited tool will greatly improve the treatment safety and efficacy, overcoming the limits identified within the clinical trials carried out so far.
•A fast GPU based MC has been developed for IOeRT breast treatment planning.•The input is an ultrasound image with defined PTV and OARs.•Different applicator positions, dimensions and angles and beam energies are tested.•Plan is optimised using absorbed dose maps and related DVHs.•Results in the context of conventional and FLASH irradiations are discussed.
The treatment of deep-seated tumours with electrons of very high energies (VHEE, 70–150 MeV) has already been explored in the past, suggesting that a dosimetric coverage comparable with ...state-of-the-art proton (PT) or photon radiotherapy (RT) could be achieved with a large (
>
10) number of fields and high electron energy. The technical and economical challenges posed by the deployment of such beams in treatment centres, together with the expected small therapeutic gain, prevented the development of such technique. This scenario could radically change in the light of recent developments that occurred in the compact, high-gradient, electron acceleration technology and, additionally, of the experimental evidence of the sparing of organs at risk achieved in ultra-high dose rate irradiation, also referred to as FLASH. Electrons with the energy required to treat intracranial lesions could be provided, at dose rates compatible with what is needed to trigger the FLASH effect, by accelerators that are a few metres long, and the organ sparing could be exploited to significantly simplify the irradiation geometry, decreasing the number of fields needed to treat a patient. In this paper, the case of two patients affected by a chordoma and a meningioma, respectively, treated with protons in Trento (IT) is presented. The proton plans have been compared with VHEE plans and X-ray intensity-modulated radiotherapy (IMRT) plans. The VHEE plans were first evaluated in terms of physical dose distribution and then assuming that the FLASH regimen can be achieved. VHEE beams demonstrated their potential in obtaining plans that have comparable tumour coverage and organs at risk sparing when benchmarked against current state-of-the-art IMRT and PT. These results were obtained with a number of explored fields that was in the range between 3 and 7, consistent with what is routinely performed in IMRT and PT conventional irradiations. The FLASH regimen, in all cases, showed its potential in reducing damage to the organs placed nearby the target volume, allowing, particularly in the chordoma case where the irradiation geometry is more challenging, a better tumour coverage with respect to the conventional treatments.
Purpose: Intraoperative electron radiotherapy (IOeRT) is considered the first clinical translation of FLASH with electrons. A crucial aspect is represented by the precise dose monitoring and ...measurement; to this aim, we propose a method fully based on Monte Carlo (MC) simulation that uses as input the beam current measurement and the beam optics simulation. To validate this approach, we chose the NOVAC11 (produced by Sordina IORT Technologies SpA) accelerator, which provides a well-studied model. Methods: We used FLUKA and FRED MC software to simulate in detail the geometry of the NOVAC11 and the coupled applicator usually adopted in clinical practice to deliver the dose in the surgical bed. The simulation results of the longitudinal and off-axis profiles and dose per pulse obtained in a water phantom with different applicators are compared to the experimental data. Results: A very good agreement not only for the relative dosimetry in both the longitudinal and off-axis profiles, with a gamma index pass rate of 100% with 3%/3 mm acceptance criteria, but also for the absolute dosimetry was obtained. Conclusion: The results completely validate the MC description of the system and provide a reliable evaluation of the dose per pulse and output factor with an accuracy of the order of few % for different sets of applicator diameters and lengths.
In recent years, there has been a stronger emphasis on the need for cultural literacy, which has allowed educators to step up and teach aspects of diversity education. These types of courses allow ...students from any background to gain a better understanding of self, as well as learn how to communicate, ask questions, and seek understanding from individuals in other cultural contexts. Focused specifically on equipping students with skills necessary to communicate across cultures, this study examined the learning and application experiences of self-identified white students after they completed an intercultural communication course. Using interviews to understand the students' experiences, the researchers derived four major themes: the need for a safe classroom environment, a better understanding of identity and self, value and need for the course in undergraduate curricula, and room to grow. This study explores these experiences to help educators within the field of agriculture and natural resources better navigate the development of their diversity education courses to be salient and productive with their students.
The Biggest Eye Opener Suarez, C. E.; Shellhouse, J. A.; Muscato, A. F.
NACTA journal,
11/2019, Volume:
64, Issue:
1
Journal Article
Peer reviewed
In recent years, there has been a stronger emphasis on the need for cultural literacy, which has allowed educators to step up and teach aspects of diversity education. These types of courses allow ...students from any background to gain a better understanding of self, as well as learn how to communicate, ask questions, and seek understanding from individuals in other cultural contexts. Focused specifically on equipping students with skills necessary to communicate across cultures, this study examined the learning and application experiences of self-identified white students after they completed an intercultural communication course. Using interviews to understand the students' experiences, the researchers derived four major themes: the need for a safe classroom environment, a better understanding of identity and self, value and need for the course in undergraduate curricula, and room to grow. This study explores these experiences to help educators within the field of agriculture and natural resources better navigate the development of their diversity education courses to be salient and productive with their students.
