Biological Effects Of Radiation Research Articles

PROPOSAL FOR A EUROPEAN METROLOGY NETWORK ON BIOLOGICAL IONISING RADIATION EFFECTS.

Progress in the field of ionising radiation (IR) metrology achieved in the BioQuaRT project raised the question to what extent radiobiological investigations would benefit from metrological support of the applied methodologies. A panel of experts from the medical field, fundamental research and radiation protection attended a workshop at Physikalisch-Technische Bundesanstalt to consult on metrology needs related to biological radiation effects. The panel identified a number of metrological needs including the further development of experimental and computational techniques for micro- and nanodosimetry, together with the determination of related fundamental material properties and the establishment of rigorous uncertainty budgets. In addition to this, a call to develop a metrology support for assisting quality assurance of radiobiology experiments was expressed. Conclusions from the workshop were presented at several international conferences for further discussion with the scientific community and stakeholder groups that led to an initiative within the metrology community to establish a European Metrology Network on biological effects of IR.

International coordination of research: EPRI International Dose Effect Alliance

Purpose: The key to increasing our understanding of low dose effects of ionizing radiation is cooperation and communication between research organizations around the world. The purpose of this article is to describe the Electric Power Research Institute (EPRI) program for such cooperation.Materials and methods: EPRI is an independent, non-profit organization dedicated to research support for the generation, transmission, and utilization of electricity. As part of its robust program, EPRI has sought to support research into low dose ionizing radiation health effects. Starting in 2016, one piece of the radiation safety program has been the International Dose Effect Alliance (IDEA), the mission of which is to organize collaborative meetings to bring together researchers from around the world to discuss research agendas, programs, and priorities.Results: IDEA workshops were held in the fall of 2016 and 2017, and were successful in starting the dialogue toward increased collaboration within the United States, Canada, Asia, and Europe. EPRI supports global collaboration and cooperation as a key opportunity to build upon the work being undertaken throughout the world to create a unified effort to answer the questions of low dose and dose rate ionizing radiation health effects. The International Workshop on the Biological Effects of Radiation, which was held in Osaka, Japan in March 2018, provided a further opportunity to expand upon the initiative for global collaboration.Conclusions: Significant advances are being achieved through the IDEA program, and the Osaka workshop held in Japan in March 2018 has further contributed to the initiative.

DNA damage response of clinical carbon ion versus photon radiation in human glioblastoma cells

Background and purposeCarbon ion radiotherapy is a promising therapeutic option for glioblastoma patients due to its high physical dose conformity and greater biological effectiveness than photons. However, the biological effects of carbon ion radiation are still incompletely understood. Here, we systematically compared the biological effects of clinically used carbon ion radiation to photon radiation with emphasis on DNA repair. Materials and methodsTwo human glioblastoma cell lines (U87 and LN229) were irradiated with carbon ions or photons and DNA damage response was systematically analyzed, including clonogenic survival, induction and repair of DNA double-strand breaks (DSBs), cell cycle arrest and apoptosis or autophagy. γH2AX foci were analyzed by flow cytometry, conventional light microscopy and 3D superresolution microscopy. ResultsDSBs were repaired delayed and with slower kinetics after carbon ions versus photons. Carbon ions caused stronger and longer-lasting cell cycle delays, predominantly in G2 phase, and a higher rate of apoptosis. Compared to photons, the effectiveness of carbon ions was less cell cycle-dependent. Homologous recombination (HR) appeared to be more important for DSB repair after carbon ions versus photons in phosphatase and tensin homolog (PTEN)-deficient U87 cells, as opposed to PTEN-proficient LN229 cells. ConclusionCarbon ions induced more severe DSB damage than photons, which was repaired less efficiently in both cell lines. Thus, carbon ion radiotherapy may help to overcome resistance mechanisms of glioblastoma associated with DNA repair for example in combination with repair pathway-specific drugs in the context of personalized radiotherapy.

Research on design of seed irradiation device based on 252Cf fission neutron source

252Cf neutron source has been widely used in biological effects of neutron radiation, neutron activation analysis and nuclear data acquisition. A seed irradiation device based on 252Cf fission neutron source was designed in this paper to study mutation breeding induced by neutron irradiation and biological effects of radiation. Based on the Monte Carlo method, neutron absorbed dose of pea seed samples in the designed irradiation region was simulated and calculated by MCNP. Results demonstrated that the relative standard deviation of the absorbed dose of pea seed samples in the three-layer partition is controlled lower than 10%, indicating the high dose uniformity in designed irradiation region. The experiment verified that the design of shield in this device meet the irradiation protection requirements.

Research Progress on the Biological Effects of Low-Dose Radiation in China.

Human are exposed to ionizing radiation from natural and artificial sources, which consequently poses a possible risk to human health. However, accumulating evidence indicates that the biological effects of low-dose radiation (LDR) are different from those of high-dose radiation (HDR). Low-dose radiation–induced hormesis has been extensively observed in different biological systems, including immunological and hematopoietic systems. Adaptive responses in response to LDR that can induce cellular resistance to genotoxic effects from subsequent exposure to HDR have also been described and researched. Bystander effects, another type of biological effect induced by LDR, have been shown to widely occur in many cell types. Furthermore, the influence of LDR-induced biological effects on certain diseases, such as cancer and diabetes, has also attracted the interest of researchers. Many studies have suggested that LDR has the potential antitumor and antidiabetic complications effects. In addition, the researches on whether LDR could induce stochastic effects were also debated. Studies on the biological effects of LDR in China started in 1970s and considerable progress has been made since. In the present article, we provide an overview of the research progress on the biological effects of LDR in China.

The medical application of terahertz technology in non-invasive detection of cells and tissues: opportunities and challenges.

Terahertz (THz = 1012 Hz) spectroscopy has shown great potential in biomedical research due to its unique features, such as the non-invasive and label-free identification of living cells and medical imaging. In this review, we summarized the advantages and progresses achieved in THz spectroscopy technology for blood cell detection, cancer cell characterization, bacterial identification and biological tissue discrimination, further introducing THz imaging systems and its progress in tissue imaging. We also highlighted the biological effects of THz radiation during its biological applications and the existing challenges and strategies to accelerate future clinical applications. The future prospects for THz spectroscopy will focus on developing rapid, label-free, and convenient biosensors for point-of-care tests and THz in vivo imaging.

Assessment of Radiation Risks During Brain CT Procedures in Moroccan Hospitals

Ct scans or Computed Tomography use X-rays to make detailed pictures of the area inside the body. CT brain examinations are used to diagnose the skull, brain, paranasal sinuses, eye sockets and other various head conditions. In the other side, if patients are exposed to greater radiation doses, it is more likely that they develop a cancer or biological effect. This study aims to measure the patient radiation dose during a brain CT procedure and to assess the radiation dose and biological effects.

Simulator of radiation biological effects in tumor in order to determinate the tumor control probability

Abstract Background Currently, tumor control probability (TCP) can be determined through experiments and observations, which enable deriving its values and construction of phenomenological and mechanistic TCP models. However, there are few experiments and observations extent; for this reason the development of virtual simulations is an interesting option for the determination of TCP. Method Probabilistic descriptions were made of three kinds of cells, and the effects of radiation interaction with each tumor cell was investigated. For a homogeneously irradiated tumor with a dose d, the “TumorRBEf” simulator determines the TCP using simulations of a fractioned treatment, based on the tumor cell ratio sensitivities (cell kill and cell sublethal damage), tumor volume, cell density, and number of fractions. Results In this study, a simulator was developed to estimate the TCP using a new methodology. The TCP was calculated from a fractioned treatment as a ratio of simulations, with 100% of killed cells and total of simulations. This technique may be useful for determining optimal treatment schedules, and as a teaching tool. Conclusions Despite that the first version of this simulator neglected tumor cellular processes, such as cell repair and cell repopulation, the current version provides hypothesis-generating results. The simulator has whole probabilistic foundations, using probabilities, such as the probability of meeting a killed cell, of killing an undamaged cell, and of killing a sublethal damage cell.

Analysis of Radiation Interactions and Biological Effects for Boron Neutron Capture Therapy

The direct and indirect ionizing radiation sources for boron neutron capture therapy (BNCT)are identi?ed. The mechanisms of physical, chemical and biological radiation interactions for BNCT are systematically described and analyzed. The relationship between the effect of biological radiation and radiation dose are illustrated and analyzed for BNCT. If the DNAs in chromosomes are damaged by ion- izing radiations, the instructions that control the cell function and reproduction are also damaged. This radiation damage may be reparable, irreparable, or incorrectly repaired. The irreparable damage can result in cell death at next mitosis while incorrectly repaired damage can result in mutation. Cell death leads to variable degrees of tissue dysfunction, which can affect the whole organism’s functions. Can- cer cells cannot live without oxygen and nutrients via the blood supply. A cancer tumor can be shrunk by damaging angiogenic factors and/or capillaries via ionizing radiations to decrease blood supply into the cancer tumor. The collisions between ionizing radiations and the target nuclei and the absorption of the ultraviolet, visible light, infrared and microwaves from bremsstrahlung in the tumor can heat up and damage cancer cells and function as thermotherapy. The cancer cells are more chemically and biologically sensitive at the BNCT-induced higher temperatures since free-radical-induced chemical re- actions are more random and vigorous at higher temperatures after irradiation, and consequently the cancer cells are harder to divide or even survive due to more cell DNA damage. BNCT is demonstrated via a recent clinical trial that it is quite effective in treating recurrent nasopharyngeal cancer.

The mechanism of bystander effect induced by different irradiation in human neuroblastoma cells

Cells exposed with irradiation can induce different biological effects in non-irradiated cells due to the cell-cell interactions. Herein, we investigated the bystander effect of different types of irradiation including gamma irradiation (GR) and lithium heavy ion irradiation (LR) on the model human neuroblastoma cell line (SH-SY5Y). The gamma and lithium ion irradiation induced different bystander effects on the SH-SY5Y cell line. The bystander effect induced by gamma irradiation promoted the cell proliferation through activating the ERK and AKT signaling pathways, but it could slightly influence the cell cycle of non-irradiated SH-SY5Y cells. Whereas, the bystander effect induced by lithium heavy ion irradiation inhibited the cell proliferation, arrested the cell cycle and activated the process of pro-apoptosis. The findings of this study confirm the diversified bystander effects of various irradiation on the non-irradiated cells, therefore it highlights the importance of revised strategy for clinical radiotherapy and radioprotection to reduce the damages caused by bystander effects. Further, the in-depth mechanism research on the cell proliferation influenced by the bystander effect of radiation will also be useful to understand the biological effects of radiation.

Approaches for Surveying Cosmic Radiation Damage in Large Populations of Arabidopsis thaliana Seeds – Antarctic Balloons and Particle Beams

Abstract The Cosmic Ray Exposure Sequencing Science (CRESS) payload system was a proof of concept experiment to assess the genomic impact of space radiation on seeds. CRESS was designed as a secondary payload for the December 2016 high-altitude, long-duration south polar balloon flight carrying the Boron and Carbon Cosmic Rays in the Upper Stratosphere (BACCUS) experiment. Investigation of the biological effects of Galactic Cosmic Radiation (GCR), particularly those of ions with High-Z and Energy (HZE), was of interest due to the genomic damage this type of radiation inflicts. The biological effects of radiation above Antarctica (ANT) were studied using Arabidopsis thaliana seeds and compared to a simulation of GCR at Brookhaven National Laboratory (BNL) and to laboratory control seeds. The CRESS payload was broadly designed to 1U CubeSat specifications (10 cm × 10 cm × 10 cm, ≤1.33 kg), maintained 1 atm internal pressure, and carried an internal cargo of 580,000 seeds and twelve CR-39 Solid-State Nuclear Track Detectors (SSNTDs). Exposed BNL and ANT M0 seeds showed significantly reduced germination rates and elevated somatic mutation rates when compared to non-irradiated controls, with the BNL mutation rate also being higher than that of ANT. Genomic DNA from plants presenting distinct aberrant phenotypes was evaluated with whole-genome sequencing using PacBio SMRT technology, which revealed an array of structural genome variants in the M0 and M1 plants. This study was the first whole-genome characterization of space-irradiated seeds and demonstrated both the efficiency and efficacy of Antarctic long-duration balloons for the study of space radiation effects on eukaryote genomes.

Evaluating Gamma-H2AX Expression as a Biomarker of DNA Damage after X-ray in Angiography Patients

Coronary heart disease (CHD) is one of the most common diseases. Coronary angiography (CAG) is an important apparatus used to diagnose and treat this disease. Since angiography is performed through exposure to ionizing radiation, it can cause harmful effects induced by double-stranded breaks in DNA which is potentially life-threatening damage. The aim of the present study is to investigate phosphorylation of Histone H2AX in the location of double-stranded breaks in peripheral blood lymphocytes as an indication of biological effects of radiation on angiography. This method is based on the phosphorylation measurement of Histone (gamma-H2AX or γ-H2AX) levels on serine 139 after the formation of DNA double-strand break. 5 cc of blood samples from 24 patients undergoing angiography were taken pre- and post-radiation. Blood lymphocytes were extracted, fixed and stained with specific γ-H2AX antibodies. Finally, the percentage of phosphorylation of Histone H2AX as an indicator of double-strand break was measured by a cytometry technique. An increase was observed in all patients' percentage of phosphorylated Histone H2AX (double-stranded breaks DNA) after radiation (20.15 ± 14.18) compared to pre-exposure time (1.52 ± 0.34). Also, the mean of DNA double-strand break is shown in a linear correlation with DAP. Although induction of DNA double-strand breaks was associated with the radiation dose in patients, the effect of individual factors such as radio-sensitivity and regenerative capacity should not be ignored. In the future, if we are able to measure DNA damage response in every angiography patient, we will use it as a biomarker for the patient dose; this will promote public health. Using flow cytometers readings done automatically is possible to detect γ-H2AX in the number of blood cells, therefore, the use of this technique could play a significant role in monitoring patients.

CLINICAL AND DOSIMETRIC INFORMATION TO SUPPORT LONG-TERM COHORT STUDY OF CHERNOBYL CLEAN-UP WORKERS IN RUSSIA.

The article describes the activities of the Russian National Radiation-Epidemiological Registry (NRER) as the unified federal information system for research and management of individual medical and dosimetry data of people exposed to radiation as a result of the Chernobyl accident and other radiological events. The NRER was created for long-term registration of lifetime changes in the health status of the registered people. We present medical and dosimetry data management process, which is carried out in compliance with approved protocols. The scope and content of the information to be collected from external resources are defined in the documents approved by the Russian Ministry of Health. As of 2017 reporting year, the NRER contains medical and dosimetry information on 205 044 clean-up workers of the Chernobyl accident (liquidators), collected during the follow-up period from 1986 to 2016. Using special software for management of data from long-term studies of the Russian cohort of Chernobyl liquidators NRER ensures high quality of radiation-epidemiological information. The results of research activities of the NRER make great contribution to understanding biological and health effects of low-level radiation, molecular mechanisms of the effects, development of actions to early diagnostic of radiation-related diseases to respond to the needs of the affected population while minimizing unnecessary anxiety, improvement of targeting treatments delivery to exposed people at high risk, development of measures to reduce health risks from medical radiological procedures. During the post-Chernobyl period, new methods for estimating radiation doses were developed, some of them can be used for express estimation of radiation dose in the event of radiological emergency.

Medical Interns’ and Residents’ Awareness of Radiation Protection in Pediatric Diagnostic Imaging

Background: The exposure of patients and radiation workers to ionizing radiation is evaluated in most cases on the basis of risk versus benefit. Any unnecessary exposure of the entire community is an unacceptable risk. Objectives: The purpose of this paper was to assess medical interns and residents’ awareness of radiation protection in pediatric diagnostic imaging. Methods: This descriptive cross-sectional study was conducted on 270 medical interns and residents. Data collection was done using a questionnaire prepared according to a literature review, with confirmed validity and reliability. After collecting and scoring the questionnaires, the data were extracted and analyzed by descriptive statistics, independent t-test, and Pearson’s correlation coefficient. Results: The participants’ awareness of pediatric diagnostic imaging was 75.55% and awareness of the principles of biological effects of radiation was 62%. There was a significant difference between the awareness of residents (59.16%) and that of interns (52.22%) (P = 0.01). The results for the two groups also showed that there was a significant difference between the level of knowledge about the dose received during imaging in both male and female groups (P = 0.04). Conclusions: Based on the results, in order to reduce children’s exposure to radiation, it is recommended to enhance the awareness and knowledge of general and specialized medical students at universities and hospitals through retraining courses.

Proton radiation-induced cancer progression

There are considerable health risks related to ionizing and proton radiation exposure. While there is a long history of health risks associated with ionizing (photon) radiation exposure, there is a limited understanding of the long-term health risks associated with proton radiation exposure. Since proton radiation is becoming more common in cancer therapy, the long-term biological effects of proton radiation remain less well characterized in terms of radiotherapy and well as for astronauts during deep space explorations. In this study, we compared the long-term side effects of proton radiation to equivalent doses of X-rays in the initiation and progression of premalignant lesions in a lung cancer susceptible mouse model (K-rasLA1). We show proton irradiation causes more complex DNA damage that is not completely repaired resulting in increased oxidative stress in the lungs both acutely and persistently. We further observed K-rasLA1 mice irradiated with protons had an increased number and size of initiated and premalignant lesions and adenomas that were often infiltrated with inflammatory cells. Proton irradiated mice had a lower median survival and increased carcinoma incidence as compared to unirradiated controls and X-rays exposed mice. Our conclusion is that exposure to proton irradiation enhances the progression of premalignant lesions to invasive carcinomas through persistent DNA damage, chronic oxidative stress, and immunosuppression.

Cyclooxygenase‑2‑mediated upregulation of heme oxygenase 1 mitigates the toxicity of deuterium‑tritium fusion radiation.

Utilizing the energy released from the nuclear fusion of deuterium with tritium (D-T) may be an important method of supplying energy in the future. The ionizing radiation emitted from nuclear fusion is a potential health risk to humans, including scientists who are currently performing nuclear fusion experiments and the employees of fusion nuclear plants, in the future. However, there have been few reports on the biological effects of fusion radiation. In the present study, using the High Intensity D-T Fusion Neutron Generator, the DNA damage and its regulation in normal human fibroblasts exposed to fusion radiation were investigated. Heme oxygenase 1 (HO-1), which is reported to induce anti-inflammatory activity, was upregulated in the irradiated cells. Pretreatment with the HO-1 inhibitor, protoporphyrin IX zinc (II), exacerbated double strand break formation following exposure to fusion radiation. The expression of cyclooxygenase-2 (COX-2) contributed to the upregulation of HO-1, as demonstrated by the result that its inhibitor, NS-398, inhibited the induction of HO-1 in irradiated cells. It was further clarified that the ataxia telangiectasia mutated DNA damage response was activated and it stimulated the phosphorylation of p38 mitogen-activated protein kinase, which was responsible for the upregulation of COX-2 and HO-1. These results provide novel information on fusion radiation-induced biological effects and potential targets for decreasing the associated health risks.

2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging-Best Practices for Safety and Effectiveness, Part 1: Radiation Physics and Radiation Biology: A Report of the American College of Cardiology Task Force on Expert Consensus Decision Pathways Developed in Collaboration With Mended Hearts.

The stimulus to create this document was the recognition that ionizing radiation-guided cardiovascular procedures are being performed with increasing frequency, leading to greater patient radiation exposure and, potentially, to greater exposure for clinical personnel. Although the clinical benefit of these procedures is substantial, there is concern about the implications of medical radiation exposure. The American College of Cardiology leadership concluded that it is important to provide practitioners with an educational resource that assembles and interprets the current radiation knowledge base relevant to cardiovascular procedures. By applying this knowledge base, cardiovascular practitioners will be able to select procedures optimally, and minimize radiation exposure to patients and to clinical personnel. Optimal Use of Ionizing Radiation in Cardiovascular Imaging: Best Practices for Safety and Effectiveness is a comprehensive overview of ionizing radiation use in cardiovascular procedures and is published online. To provide the most value to our members, we divided the print version of this document into 2 focused parts. Part I: Radiation Physics and Radiation Biology addresses the issue of medical radiation exposure, the basics of radiation physics and dosimetry, and the basics of radiation biology and radiation-induced adverse effects. Part II: Radiological Equipment Operation, Dose-Sparing Methodologies, Patient and Medical Personnel Protection covers the basics of operation and radiation delivery for the 3 cardiovascular imaging modalities (x-ray fluoroscopy, x-ray computed tomography, and nuclear scintigraphy) and will be published in the next issue of the Journal.

Organ at risk dose comparison between gynaecological cancers of the endometrium and cervix using a combined external beam and brachytherapy boost treatment

Gynaecological cancers (GCs) treated using external beam radiotherapy (EBRT) followed by a boost of brachytherapy (BT) reduces the overall treatment dose and gives a better treatment of the tumour compared to using EBRT or BT alone. However, with this combined treatment, there is growing concern for the increased dose to the Organs at Risk (OAR) as it increases the possibility of late toxicity effects and potentially reduces the patient’s quality of life (QoL). Using statistical analysis, the differences in dose delivered to the OAR for two GCs (endometrial and cervical) was investigated as well as other dose influencing factors (i.e. applicator insertion angle and size). This project involved 19 cervical patients: EBRT = 50.4 Gy, 28 fractions followed by BT = 21 Gy, 3 fractions; and 17 endometrial patients: EBRT = 45/46 Gy, 28 fractions and BT = 18 Gy 3 fractions. All patients had been treated with 3D-Conformal EBRT using 15 MV photon beams and BT with a Ir-192 GammaMed Plus system. Statistically significant differences (p-value < 0.05) between the OAR doses for the two GC treatments identified that cervical patients receive a higher dose to the bladder, sigmoid and small intestines, with a reduction in rectum dose due to the use of a rectum retractor in BT treatments. Total Reference Air KERMA (TRAK), a potential predictive factor for the biological effect of radiation on tissues, also showed that cervical treatments exhibited much higher TRAK values than when compared with endometrial treatments (p-value < 0.0001). Gynaecological cancers (GCs) treated using external beam radiotherapy (EBRT) followed by a boost of brachytherapy (BT) reduces the overall treatment dose and gives a better treatment of the tumour compared to using EBRT or BT alone. However, with this combined treatment, there is growing concern for the increased dose to the Organs at Risk (OAR) as it increases the possibility of late toxicity effects and potentially reduces the patient’s quality of life (QoL). Using statistical analysis, the differences in dose delivered to the OAR for two GCs (endometrial and cervical) was investigated as well as other dose influencing factors (i.e. applicator insertion angle and size). This project involved 19 cervical patients: EBRT = 50.4 Gy, 28 fractions followed by BT = 21 Gy, 3 fractions; and 17 endometrial patients: EBRT = 45/46 Gy, 28 fractions and BT = 18 Gy 3 fractions. All patients had been treated with 3D-Conformal EBRT using 15 MV photon beams and BT with a Ir-192 GammaMed Plus system. Statistically significant differences (p-value < 0.05) between the OAR doses for the two GC treatments identified that cervical patients receive a higher dose to the bladder, sigmoid and small intestines, with a reduction in rectum dose due to the use of a rectum retractor in BT treatments. Total Reference Air KERMA (TRAK), a potential predictive factor for the biological effect of radiation on tissues, also showed that cervical treatments exhibited much higher TRAK values than when compared with endometrial treatments (p-value < 0.0001).

Genotoxic Effects in Human Fibroblasts Exposed to Microwave Radiation.

In the last decades, technological development has led to an increasing use of devices and systems based on microwave radiation. The increased employment of these devices has elicited questions about the potential long-term health consequences associated with microwave radiation exposure. From this perspective, biological effects of microwave radiation have been the focus of many studies, but the reported scientific data are unclear and contradictory. The aim of this study is to evaluate the potential genotoxic and cellular effects associated with in vitro exposure of human fetal and adult fibroblasts to microwave radiation at the frequency of 25 GHz. For this purpose, several genetic and biological end points were evaluated. Results obtained from comet assay, phosphorylation of H2AX histone, and antikinetochore antibody (CREST)-negative micronuclei frequency excluded direct DNA damage to human fetal and adult fibroblasts exposed to microwaves. No induction of apoptosis or changes in prosurvival signalling proteins were detected. Moreover, CREST analysis showed for both the cell lines an increase in the total number of micronuclei and centromere positive micronuclei in exposed samples, indicating aneuploidy induction due to chromosome loss.

Characteristics Analysis of High Energy External Radiotherapy Beams in Water

High energy external radiotherapy beam is being used widely for cancer treatment. Biological effect of radiation is concerned with the evaluation of energy absorbed in the tissue. The study of photon and electron beam characteristics is necessary before calibration machine. The aim of this study was to analysis characteristics of depth dose of different energy beams in water to enhance the quality of the radiotherapy treatment planning. Beam is attenuated by the medium and the transmitted beam with less intensity causes lesser absorbed dose as the depth increases. Relative attenuation on certain points on the beam axis and certain percentage of doses on different depths for 4-15 MV photon beams and 4-18 MeV electron beams have been investigated. Depth dose characteristics of the beams do not show identical attributes as interaction of the beams with matters is mainly governed by beam quality. Attenuation and penetration parameters show variation with dosimetric parameters like field size due to scattering and source to surface distance due to inverse square law but the major parameter in interaction is energy. Detailed analysis of the beam characteristics helps to select appropriate beam for radiotherapy treatment when variety of beam energies available and hence to increase accuracy in radiotherapy treatment.&#x0D;