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Wanstall HC, Burkart F, Dinter H, Kellermeier M, Kuropka W, Mayet F, Vinatier T, Santina E, Chadwick AL, Merchant MJ, Henthorn NT, Köpke M, Stacey B, Jaster-Merz S, Jones RM. First in vitro measurement of VHEE relative biological effectiveness (RBE) in lung and prostate cancer cells using the ARES linac at DESY. Sci Rep 2024; 14:10957. [PMID: 38740830 DOI: 10.1038/s41598-024-60585-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
Very high energy electrons (VHEE) are a potential candidate for radiotherapy applications. This includes tumours in inhomogeneous regions such as lung and prostate cancers, due to the insensitivity of VHEE to inhomogeneities. This study explores how electrons in the VHEE range can be used to perform successful in vitro radiobiological studies. The ARES (accelerator research experiment at SINBAD) facility at DESY, Hamburg, Germany was used to deliver 154 MeV electrons to both prostate (PC3) and lung (A549) cancer cells in suspension. Dose was delivered to samples with repeatability and uniformity, quantified with Gafchromic film. Cell survival in response to VHEE was measured using the clonogenic assay to determine the biological effectiveness of VHEE in cancer cells for the first time using this method. Equivalent experiments were performed using 300 kVp X-rays, to enable VHEE irradiated cells to be compared with conventional photons. VHEE irradiated cancer cell survival was fitted to the linear quadratic (LQ) model (R2 = 0.96-0.97). The damage from VHEE and X-ray irradiated cells at doses between 1.41 and 6.33 Gy are comparable, suggesting similar relative biological effectiveness (RBE) between the two modalities. This suggests VHEE is as damaging as photon radiotherapy and therefore could be used to successfully damage cancer cells during radiotherapy. The RBE of VHEE was quantified as the relative doses required for 50% (D0.5) and 10% (D0.1) cell survival. Using these values, VHEE RBE was measured as 0.93 (D0.5) and 0.99 (D0.1) for A549 and 0.74 (D0.5) and 0.93 (D0.1) for PC3 cell lines respectively. For the first time, this study has shown that 154 MeV electrons can be used to effectively kill lung and prostate cancer cells, suggesting that VHEE would be a viable radiotherapy modality. Several studies have shown that VHEE has characteristics that would offer significant improvements over conventional photon radiotherapy for example, electrons are relatively easy to steer and can be used to deliver dose rapidly and with high efficiency. Studies have shown improved dose distribution with VHEE in treatment plans, in comparison to VMAT, indicating that VHEE can offer improved and safer treatment plans with reduced side effects. The biological response of cancer cells to VHEE has not been sufficiently studied as of yet, however this initial study provides some initial insights into cell damage. VHEE offers significant benefits over photon radiotherapy and therefore more studies are required to fully understand the biological effectiveness of VHEE.
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Affiliation(s)
- Hannah C Wanstall
- Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
- Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK.
- Daresbury Laboratory, The Cockcroft Institute, Daresbury, Warrington, WA4 4AD, UK.
| | - Florian Burkart
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Hannes Dinter
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Max Kellermeier
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Willi Kuropka
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Frank Mayet
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Thomas Vinatier
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Elham Santina
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Amy L Chadwick
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Michael J Merchant
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Nicholas T Henthorn
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Michael Köpke
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Blae Stacey
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Sonja Jaster-Merz
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
| | - Roger M Jones
- Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- Daresbury Laboratory, The Cockcroft Institute, Daresbury, Warrington, WA4 4AD, UK
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Tamizh Selvan G, Kanagaraj K, Venkatachalam P. The relative biological effectiveness of high-energy clinical 3 and 6 MV X-rays for micronucleus induction in human lymphocytes. Int J Radiat Biol 2021; 97:687-694. [PMID: 33798020 DOI: 10.1080/09553002.2021.1906972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/20/2021] [Accepted: 03/18/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE In the modern era of radiotherapy, use of conventional radiation modalities (based on γ-rays) is being replaced by high-energy linear accelerator-based X-rays. As a result of mishandling of equipment or mechanical errors, health workers can be exposed to these high-energy X-rays. Especially in the absence of personnel monitoring devices, biodosimetry with a lower energy X-ray calibration curve may not provide an acceptable dose estimate. Moreover, the relative biological effectiveness (RBE) value assigned for X-rays is the same (ONE) regardless of beam energy (V), employed in diagnosis, interventional medicine, and radiotherapy. Therefore, the purpose of the study is to examine the induced biological effects, measured through micronucleus (MN) formation, of X-rays of different energies (3 and 6 MV X-rays), and to investigate the RBE relative to 225 kVp X-rays. MATERIALS AND METHODS Peripheral blood lymphocytes (PBLs) from healthy donors (n = 6), were irradiated with 225 kVp, 3 MV, and 6 MV energy X-rays and induced biological damage was quantified as MN formation using the cytokinesis blocked MN (CBMN) assay. RESULTS The MN per cell in the X-irradiated samples for the three different X-ray energies showed a significant (p<.0001) dose-dependent increase, when compared to unexposed samples. Aberration frequencies obtained at the same dose for the three different energies showed significant (p<.05) difference for the MN per cell among the energy levels; however, the in vitro dose-response curve parameters (slope, intercept, and coefficient) did not show any significant differences. The estimated dose in the blinded sample was within the 95% confidence intervals of each of the calibration curves. However, overall, the 6 MV dose-response curve coefficients yielded the closest dose estimate to that of the true dose. The calculated RBE values at 5% induced MN for 3 and 6 MV LINAC X-rays were 2.0 ± 0.04 and 0.70 ± 0.01, respectively, and the average RBE for the complete dose-response curves were 1.13 ± 0.04 and 0.80 ± 0.02 relative to 225 kVp X-rays as standard radiation. CONCLUSION The established dose-response curves obtained for PBL exposed to different energy levels of X-rays of 225 kVp, 3 MV, and 6 MV are ready to use for biological dosimetry purposes. The calculated RBE values for the higher energies of X-rays relative to 225 kVp X-rays in this study suggest that RBE of X-rays may not be equal to one, with the true value dependent on the beam energy, the dose and dose rate, and the endpoint investigated.
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Affiliation(s)
- G Tamizh Selvan
- Central Research Lab, K.S. Hegde Medical Academy, Nitte (Deemed to be University), Mangalore, India
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, India
| | - Karthik Kanagaraj
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, India
| | - Perumal Venkatachalam
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, India
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Effects of radiation quality and dose rate on radiation-induced nucleoplasmic bridges in human peripheral blood lymphocytes. Mutat Res 2021; 863-864:503321. [PMID: 33678246 DOI: 10.1016/j.mrgentox.2021.503321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/13/2021] [Accepted: 01/25/2021] [Indexed: 11/22/2022]
Abstract
Previous studies showed that the yield of cobalt-60 γ-rays-induced nucleoplasmic bridges (NPB) in human peripheral blood lymphocytes is dose dependent. However, the influence of the radiation quality and dose rates on NPB frequencies has not been investigated. The present study aimed to investigate NPB frequencies in human peripheral blood lymphocytes induced by carbon ions and explore the dose rate effect on cobalt-60 γ-rays-induced NPB. To establish dose-response curves, human peripheral blood samples were irradiated with 0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 and 8.0 Gy of carbon ions at a dose rate of 3.0 Gy/min in vitro. To explore the dose rate effect, human peripheral blood samples were irradiated with 2.0 and 5.0 Gy of cobalt-60 γ-rays at dose rates of 0.2, 0.5, 1.0, 3.0, 5.0 and 10.0 Gy/min in vitro. NPB and micronuclei (MN) in binucleated cells were analyzed with the cytokinesis-block micronucleus cytome assay. Results showed that the dose-response curve of carbon ion-induced NPB frequencies follow a linear-quadratic model (R2 = 0.934). The relative biological effectiveness (RBE) values of carbon ions to cobalt-60 γ-rays decreased with increased NPB frequencies (ranging from 2.47 to 5.86). Compared with group 1.0 Gy/min, the NPB frequencies in groups 10.0 Gy/min (2.0 Gy), 5.0 and 10.0 Gy/min (5.0 Gy) were decreased significantly (P < 0.05). Carbon ion-induced NPB in human peripheral blood lymphocytes have a good dose-response relationship. Cobalt-60 γ-rays-induced NPB frequencies are affected by the specific dose rate.
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Mendes ME, Mendonça JCGD, Hwang S, Giorgio MD, Lima FFD, Santos N. Calibration curves by 60Co with low dose rate are different in terms of dose estimation - a comparative study. Genet Mol Biol 2020; 43:e20180370. [PMID: 32105287 PMCID: PMC7231543 DOI: 10.1590/1678-4685-gmb-2018-0370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 12/17/2019] [Indexed: 01/08/2023] Open
Abstract
Biological dosimetry aims to estimate individual absorbed doses due ionizing
radiation exposure. The dicentric chromosomes are considered the most specific
biomarker for dose estimation. This study aimed to compare calibration curves
for linear low energy transfer (LET) radiation built from low dose rates and
whether they vary in terms of dose estimation. For that we did a search in the
literature of all calibration curves produced with low dose rates and we
simulated the dose estimation from pre-established dicentric’s frequencies. The
information on methodologies and cytogenetic results of each study were
analyzed. As expected dose rate influence β coefficients, especially at higher
doses. However, we have seen that some doses were not statistically different
but they should be, because there is a significant association between the
productions of dicentrics and dose rate. This comparative study reinforced the
robustness of the dicentric assay and its importance in biological dosimetry. We
also emphasized that the dose rate was an important factor in dose estimations.
Thus, intercomparison exercises should take into account the dose rates of the
participating laboratories, because the dose rates might explain why some
results of estimated doses fall outside the recommendations.
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Affiliation(s)
- Mariana Esposito Mendes
- Universidade Federal de Pernambuco, Departamento de Genética, Recife, Pernambuco, Brazil.,Centro Regional de Ciências Nucleares do Nordeste, Recife, Pernambuco, Brazil
| | | | - Suy Hwang
- Centro Regional de Ciências Nucleares do Nordeste, Recife, Pernambuco, Brazil
| | | | | | - Neide Santos
- Universidade Federal de Pernambuco, Departamento de Genética, Recife, Pernambuco, Brazil
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Rastkhah E, Zakeri F, Ghoranneviss M, Rajabpour MR, Farshidpour MR, Mianji F, Bayat M. The cytokinesis-blocked micronucleus assay: dose-response calibration curve, background frequency in the population and dose estimation. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2016; 55:41-51. [PMID: 26507139 DOI: 10.1007/s00411-015-0624-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 10/15/2015] [Indexed: 06/05/2023]
Abstract
An in vitro study of the dose responses of human peripheral blood lymphocytes was conducted with the aim of creating calibrated dose-response curves for biodosimetry measuring up to 4 Gy (0.25-4 Gy) of gamma radiation. The cytokinesis-blocked micronucleus (CBMN) assay was employed to obtain the frequencies of micronuclei (MN) per binucleated cell in blood samples from 16 healthy donors (eight males and eight females) in two age ranges of 20-34 and 35-50 years. The data were used to construct the calibration curves for men and women in two age groups, separately. An increase in micronuclei yield with the dose in a linear-quadratic way was observed in all groups. To verify the applicability of the constructed calibration curve, MN yields were measured in peripheral blood lymphocytes of two real overexposed subjects and three irradiated samples with unknown dose, and the results were compared with dose values obtained from measuring dicentric chromosomes. The comparison of the results obtained by the two techniques indicated a good agreement between dose estimates. The average baseline frequency of MN for the 130 healthy non-exposed donors (77 men and 55 women, 20-60 years old divided into four age groups) ranged from 6 to 21 micronuclei per 1000 binucleated cells. Baseline MN frequencies were higher for women and for the older age group. The results presented in this study point out that the CBMN assay is a reliable, easier and valuable alternative method for biological dosimetry.
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Affiliation(s)
- E Rastkhah
- Islamic Azad University, Science Research Branch, Tehran, Iran
| | - F Zakeri
- Nuclear Science and Technology Research Institute, Tehran, Iran.
- Iran Nuclear Regulatory Authority, Tehran, Iran.
| | - M Ghoranneviss
- Islamic Azad University, Science Research Branch, Tehran, Iran
| | | | | | - F Mianji
- Nuclear Science and Technology Research Institute, Tehran, Iran
- Iran Nuclear Regulatory Authority, Tehran, Iran
| | - M Bayat
- Islamic Azad University, Science Research Branch, Tehran, Iran
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Acharya S, Bhat NN, Sanjeev G, Narayana Y. Evaluation of micronuclei induced by energetic electrons delivered at different dose rates per pulse. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3388-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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The cytokinesis-blocked micronucleus assay: Dose estimation and inter-individual differences in the response to γ-radiation. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2014; 760:17-22. [DOI: 10.1016/j.mrgentox.2013.09.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 08/02/2013] [Accepted: 09/28/2013] [Indexed: 11/19/2022]
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Acharya S, Bhat NN, Joseph P, Sanjeev G, Sreedevi B, Narayana Y. Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2011; 50:253-263. [PMID: 21259020 DOI: 10.1007/s00411-011-0353-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 01/07/2011] [Indexed: 05/30/2023]
Abstract
The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.
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Affiliation(s)
- Santhosh Acharya
- Department of Engineering Physics, Alva's Institute of Engineering and Technology, Moodbidri, 574225, India
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Dose rate effect of pulsed electron beam on micronucleus frequency in human peripheral blood lymphocytes. Arh Hig Rada Toksikol 2010; 61:77-83. [PMID: 20338871 DOI: 10.2478/10004-1254-61-2010-1982] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The micronucleus assay in human peripheral blood lymphocytes is a sensitive indicator of radiation damage and could serve as a biological dosimeter in evaluating suspected overexposure to ionising radiation. Micronucleus (MN) frequency as a measure of chromosomal damage has also extensively been employed to quantify the effects of radiation dose rate on biological systems. Here we studied the effects of 8 MeV pulsed electron beam emitted by Microtron electron accelerator on MN induction at dose rates between 35 Gy min-1 and 352.5 Gy min-1. These dose rates were achieved by varying the pulse repetition rate (PRR). Fricke dosimeter was employed to measure the absorbed dose at different PRR and to ensure uniform dose distribution of the electron beam. To study the dose rate effect, blood samples were irradiated to an absorbed dose of (4.7+/-0.2) Gy at different rates and cytogenetic damage was quantified using the micronucleus assay. The obtained MN frequency showed no dose rate dependence within the studied dose rate range. Our earlier dose effect study using 8 MeV electrons revealed that the response of MN was linear-quadratic. Therefore, in the event of an accident, dose estimation can be made using linear-quadratic dose response parameters, without adding dose rate as a correction factor.
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