We use the GEANT4 Monte Carlo code to calculate the radiation dose equivalent due to Galactic Cosmic Rays (GCRs) during an out-of-magnetosphere space flight. We provide a detailed analysis of the radiation dose composition, distinguishing between the contribution of primary GCR particles and different species of secondary particles. We show that for realistic shielding thicknesses, the radiation dose equivalent is mostly due to GCR protons and alpha particles. The Blood-Forming Organs (BFO) dose equivalent is the same in the shielding spheres with the radius of 50 and 100 cm, although the dose composition differs. We show that indirectly scattered secondary particles make up to 60% to the net radiation dose. Up to 90% of the secondary neutron dose equivalent is associated with indirectly scattered particles.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.lssr.2019.09.001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Evaluation of a Deep Learning Denoising Algorithm for Dose Reduction in Whole-Body Photon-Counting CT Imaging: A Cadaveric Study.
Acad Radiol
January 2025
Department of Radiology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tuebingen, Germany (R.D., J.M.B., B.S., J.M., S.G., P.K., S.W., J.H., K.N., S.A., A.B.).
Rationale And Objectives: Photon Counting CT (PCCT) offers advanced imaging capabilities with potential for substantial radiation dose reduction; however, achieving this without compromising image quality remains a challenge due to increased noise at lower doses. This study aims to evaluate the effectiveness of a deep learning (DL)-based denoising algorithm in maintaining diagnostic image quality in whole-body PCCT imaging at reduced radiation levels, using real intraindividual cadaveric scans.
Materials And Methods: Twenty-four cadaveric human bodies underwent whole-body CT scans on a PCCT scanner (NAEOTOM Alpha, Siemens Healthineers) at four different dose levels (100%, 50%, 25%, and 10% mAs).
Enhancing precision in lacrimal sac tumor management through integration of multimodal imaging and intensity modulated proton therapy.
Med Dosim
January 2025
Department of Radiation Oncology, Peking University First Hospital, Beijing, China. Electronic address:
This study presents a patient with a PET-CT detected residual lacrimal sac tumor who was treated with intensity modulated proton therapy (IMPT) and concurrent chemotherapy. The patient a 49-year-old male diagnosed with squamous cell carcinoma of the left lacrimal sac had under-went endoscopic surgery. Postoperative PET-CT implied tumor residual in the left lacrimal sac.
View Article and Find Full Text PDFInverse dose protraction effects of high-LET radiation: evidence and significance.
Mutat Res Rev Mutat Res
January 2025
Radiation Epidemiology Branch, National Cancer Institute, MD 20892-9778, USA; Faculty of Health, Science and Technology, Oxford Brookes University, Headington Campus, OX3 0BP, UK.
Biological effects of ionizing radiation vary with radiation quality, which is often expressed as the amount of energy deposited per unit length, i.e., linear energy transfer (LET).
View Article and Find Full Text PDFNew imaging techniques and trends in radiology.
Diagn Interv Radiol
January 2025
Erzincan Binali Yıldırım University Faculty of Medicine, Department of Radiology, Erzincan, Türkiye.
Radiography is a field of medicine inherently intertwined with technology. The dependency on technology is very high for obtaining images in ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). Although the reduction in radiation dose is not applicable in US and MRI, advancements in technology have made it possible in CT, with ongoing studies aimed at further optimization.
View Article and Find Full Text PDFNormal tissue complication probability model for severe radiation-induced lymphopenia in patients with pancreatic cancer treated with concurrent chemoradiotherapy.
Phys Imaging Radiat Oncol
January 2025
Department of Radiation Oncology, Hokkaido University Faculty of Medicine and Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan.
Background And Purpose: Radiation-induced lymphopenia (RIL) may be associated with a worse prognosis in pancreatic cancer. This study aimed to develop a normal tissue complication probability (NTCP) model to predict severe RIL in patients with pancreatic cancer undergoing concurrent chemoradiotherapy (CCRT).
Materials And Methods: We reviewed pancreatic cancer patients treated at our facility for model training and internal validation.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!