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Lozko Y, Zelinskyi R, Stadnyk L, Brovchuk S, Iakovenko V, Kowalchuk RO, Romalis Y, Suchowerska N, Kovalchuk N. Impact of War on Radiotherapy in Ukraine. Int J Radiat Oncol Biol Phys 2023; 117:S78-S79. [PMID: 37784575 DOI: 10.1016/j.ijrobp.2023.06.395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) The full-scale Russian invasion of Ukraine on February 24th, 2022 brought the largest humanitarian disaster to the heart of Europe since the World War II. Ukraine has lost tens of thousands of civilian lives, with approximately a third of the population displaced. The Russian army is deliberately damaging and destroying hospitals and clinics. This study describes the impact of the full-scale Russian invasion on the radiation therapy (RT) services in Ukraine. MATERIALS/METHODS An annual survey was conducted by Grigoriev Institute for Medical Radiology, Kharkiv for the IAEA DIRAC database. The survey was sent to 41 RT centers in Ukraine requesting information on equipment, staffing, and patient volume. Due to the war conditions the data provided in the survey is limited. The information on operation of RT centers during the war collected by a Ukrainian Association of Medical Physicists representative is reported here as well. RESULTS After the initial Russian invasion of Ukraine in 2014 and occupation of Crimea and parts of Donbas, Ukraine lost access to 7 RT centers with 18 external beam radiotherapy (EBRT) machines (17% of total). Just before the full-scale invasion in 2022, there were a total of 44 Co-60 machines (57%) and 33 linear accelerators (43%) in the unoccupied territories. As a result of the full-scale invasion of Ukraine in 2022, almost all RT centers suspended operation in the first weeks of war. The most challenging period for RT in Ukraine was in March when Kyiv (where 20 EBRT machines are located) was partially surrounded by the occupiers. The situation improved after Ukrainians liberated approximately half of total occupied territory. Currently, 2 additional RT centers are under occupation; 3 RT centers sustained heavy shelling and equipment damage. The response rate to the survey was 63%. Compared to 2021 data, in 2022, the number of radiation oncologists decreased by 7.8%, medical physicists by 7.3%, and therapists by 10.0%. The workload in the RT centers close to the combat zone almost halved, while increasing by 10 - 60% in the western and central Ukraine. The total number of patients treated with EBRT decreased by 11% and brachytherapy by 21%. Age of the RT equipment in Ukraine is shown in Table 1. Despite the ongoing war, Ukrainian cancer centers installed 3 new linear accelerators, with 14 linear accelerators pending installation. CONCLUSION Radiotherapy in Ukraine sustained significant damages since the 2014 Russian invasion, which was exacerbated further by the full-scale invasion in 2022. To support the vitality and absorptive capacity of RT services in Ukraine, the democratic world can help by donating equipment, hardware, software, and participating in training of Ukrainian RT professionals as they transition to modern and high-quality RT care for Ukrainian cancer patients.
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Affiliation(s)
- Y Lozko
- Stanford Cancer Institute Palo Alto, Palo Alto, CA
| | - R Zelinskyi
- Ukrainian Association of Medical Physicists, Ukraine
| | - L Stadnyk
- SO «Grigoriev Institute for Medical Radiology and Oncology of the National Academy of Medical Sciences of Ukraine», Kharkiv, Ukraine
| | - S Brovchuk
- Kyiv Regional Oncology Dispensary, Kyiv, Ukraine
| | - V Iakovenko
- Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - R O Kowalchuk
- University of Virginia / Riverside Radiosurgery Center, Newport News, VA
| | - Y Romalis
- St. George's University, St. George's, Saint George, Grenada
| | | | - N Kovalchuk
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
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Rogers L, Chen B, Liu K, McKenzie D, Suchowerska N, Kwan A. PD-0934 Spatial modulation enhances the effects of radiation on cancer cells. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)07213-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Suchowerska N, Kench P, Rogers L, Estaves A, Gorjiara T, McKenzie D. OC-0682: CBCT dose prior to radiotherapy causes up to 15 times more cell death than predicted. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00704-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Suchowerska N, McKenzie D. SP-061: Targeting the physics, but missing the biology. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(20)30581-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Olejnik J, Suchowerska N, Herrid M, Jackson A, Jackson M, Andronicos NM, Hinch GN, Hill JR. Sensitivity of spermatogonia to irradiation varies with age in pre-pubertal ram lambs. Anim Reprod Sci 2018; 193:58-67. [PMID: 29636209 DOI: 10.1016/j.anireprosci.2018.03.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/23/2018] [Accepted: 03/29/2018] [Indexed: 01/15/2023]
Abstract
Although germ cells from donor rams transplanted into irradiated recipient testes have produced donor derived offspring, efficiency is low. Further optimization of recipient irradiation protocols will add precision to the depletion of recipient spermatogonia prior to germ cell transplant. Three irradiation doses (9,12,15 Gy) were administered to ram lambs aged 14 weeks (Group 1) and 20 weeks (Group 2), then testicular biopsies were collected 1, 2 and 3 months after irradiation. At 1 month after irradiation of Group 1, only the largest dose (15 Gy) reduced spermatogonia numbers below 10% of non-irradiated controls, whereas in Group 2 lambs, each irradiation dose reduced spermatogonia below 10% of controls. In both Groups, fewer differentiated germ cells were present in seminiferous tubules compared to controls. At 2 months after irradiation, spermatogonia numbers in both Groups increased more than sixfold to be similar to controls, whereas fewer differentiated germ cells were present in the tubules of both Groups. At 3 months in Group 1, each irradiation dose reduced spermatogonia numbers to <30% of controls and fewer tubules contained differentiated germ cells. Lesser expression of spermatogonial genes, VASA and UCHL-1, was observed in the 15 Gy group. In Group 2, only 12 Gy treated tubules contained fewer spermatogonia. Knowledge of these subtle differences between age groups in the effect of irradiation doses on spermatogonia or differentiated germ cell numbers and the duration of recovery of spermatogonia numbers after irradiation will aid the timing of germ cell transplants into prepubertal recipient lambs.
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Affiliation(s)
- J Olejnik
- CSIRO Food Futures National Research Flagship, Australia; CSIRO Animal, Food and Health Sciences, F. D. McMaster Laboratory, Armidale, NSW, 2350 Australia; University of New England, Armidale, NSW, 2350, Australia
| | - N Suchowerska
- School of Physics, University of Sydney, NSW, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
| | - M Herrid
- CSIRO Food Futures National Research Flagship, Australia
| | - A Jackson
- CSIRO Food Futures National Research Flagship, Australia
| | - M Jackson
- Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
| | - N M Andronicos
- CSIRO Animal, Food and Health Sciences, F. D. McMaster Laboratory, Armidale, NSW, 2350 Australia; University of New England, Armidale, NSW, 2350, Australia
| | - G N Hinch
- University of New England, Armidale, NSW, 2350, Australia
| | - J R Hill
- CSIRO Food Futures National Research Flagship, Australia; University of Queensland, School of Veterinary Science, Gatton, QLD 4343, Queensland, Australia.
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Suchowerska N, Peng V, Rogers L, Claridge- Mackonis E, McKenzie D. PO-0911: Can the therapeutic benefits of microbeam radiation therapy be achieved using a clinical linac? Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31348-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Suchowerska N, Toohey J, Carroll S, Rogers L, Lyons G, Beith J, Dos Santos Esteves A, McKenzie D. PO-0918: Radiotherapy and Her2 targeting agents: synergism and antagonism in clonogenic and confluence assays. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31355-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Kirkby C, Koger B, Suchowerska N, McKenzie D. SU-G-TeP3-13: The Role of Nanoscale Energy Deposition in the Development of Gold Nanoparticle-Enhanced Radiotherapy. Med Phys 2016. [DOI: 10.1118/1.4957093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Liu P, Reggiori G, Lobefalo F, Mancosu P, Tomatis S, McKenzie D, Suchowerska N. EP-1496: Small field correction factors for the IBA Razor. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32746-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Mackonis EC, Hammond L, Suchowerska N. EP-1927: Practical dosimetry solutions to enhance cell biology studies. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)33178-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Reggiori G, Mancosu P, Stravato A, Lobefalo F, Paganini L, Zucconi F, Palumbo V, Suchowerska N, Tomatis S, Scorsetti M. EP-1517: Characterization of a new stereotactic diode under flattening filter free beams down to small fields. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32767-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Reggiori G, Mancosu P, Suchowerska N, Lobefalo F, Stravato A, Tomatis S, Scorsetti M. Characterization of a new stereotactic diode under flattening filter free beams down to small fields. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.01.195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Ralston A, Tyler M, Liu P, McKenzie D, Suchowerska N. OC-0152: Are correction factors needed for microDiamond detectors in small fields? Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40150-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tyler M, Liu P, Lee C, McKenzie D, Suchowerska N. PO-0819: The effect of the flattening filter on detector response in small radiation fields. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40811-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rogers L, Suchowerska N, Ralston A, Napper A, McKenzie D. EP-1472: Do 4DCT and CBCT imaging doses need to be included in the planning of radiotherapy treatments? Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)41464-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hug B, Ebert M, Warrener K, Suchowerska N, Liu P, Ralston A, McKenzie D, Woodward R. PD-0035: Characterisation of a scintillation detector for stereotactic field in-air output ratios. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)30140-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Suchowerska N, Tyler M, Liu P, Chan K, Ralston A, McKenzie D, Downes S. PO-0794: Detector choice for small-field Stereotactic Radiosurgery (SRS) beam characterisation. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)30912-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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Rogers L, Suchowerska N, Ralston A, McKenzie D. EP-1627: Effect of 4DCT and CBCT Imaging doses on cell survival in subsequent radiotherapy. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)31745-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cranmer-Sargison G, Liu PZY, Weston S, Suchowerska N, Thwaites DI. Small field dosimetric characterization of a new 160-leaf MLC. Phys Med Biol 2013; 58:7343-54. [DOI: 10.1088/0031-9155/58/20/7343] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Liu PZY, Suchowerska N, McKenzie DR. Twisted pair of optic fibers for background removal in radiation fields. Appl Opt 2013; 52:5500-5507. [PMID: 23913071 DOI: 10.1364/ao.52.005500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 07/02/2013] [Indexed: 06/02/2023]
Abstract
In many situations in which an optic fiber carries a signal through a radiation field, an unwanted background signal is produced consisting of fluorescent and/or Cerenkov light. This presents a major problem in the measurement of the light signal, for example, in scintillation dosimetry of medical therapeutic beams. In this paper, we demonstrate a new method of measuring and removing the background signal through the use of a twisted pair of optic fibers. The twisted pair consists of a fiber carrying the scintillation signal that is twisted with a second optic fiber to form a double helix. The two twisted fibers will experience the same radiation environment provided the periodicity of the twist is correlated to the dose rate gradient. An expression for the required twist periodicity is presented. A scintillation dosimeter with a twisted pair optic fiber was tested in a megavoltage beam and found to accurately measure its beam characteristics. The twisted pair approach is not restricted to medical applications and can be used in many situations in which optical signals are carried through radiation fields.
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Affiliation(s)
- P Z Y Liu
- School of Physics, University of Sydney, New South Wales, Australia.
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Abstract
Whenever a fibre optic is used to convey a light signal through a radiation field, it is likely that an unwanted background signal will arise from Cerenkov or fluorescent light which will contaminate the signal. In luminescence dosimetry of high energy beams, when a fibre optic is used to convey the signal from the radiation field to the detector, Cerenkov light is the dominant contributor to the background signal and must be corrected for. In this work, a novel method is demonstrated to separate the signal from the unwanted background. A remotely operated shutter is used to block the signal, allowing the residual background in the fibre optic to be quantified. This background is subtracted from the total measurement acquired in a subsequent irradiation, enabling the luminescence signal to be extracted. Two types of shutter mechanism are considered: an electro-mechanical device to intercept the light path and an LCD device to block the light by cross-polarization. Both shutters were characterized and incorporated into a fibre optic dosimetry system used to measure the radiation dose produced by external beam radiation linear accelerators. The dosimeter using each of the shutters in turn was exposed to a 6 MV photon beam to determine their performance, including the measurement of field size dependent output factors. The mechanical shutter determined the output factors to within 0.29% of those measured with an ionization chamber, whereas the LCD shutter gave results that deviated by up to 2.4%. The switching precision of both shutters was good with standard deviations of less than 0.25% and both were able to completely block the light signal when closed. The use of shutters could therefore be applied to any fibre optic based system to quantify and remove a reproducible background arising from any source including ambient, fluorescent and Cerenkov light.
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Affiliation(s)
- J J Lee
- School of Physics, The University of Sydney, NSW 2006, Australia.
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Liu P, Cranmer-Sargison G, Ralston A, Gajewski R, Simpson E, Weston S, Thwaites D, McKenzie D, Suchowerska N. OC-0065: Small field dosimetry in flattening filter free (FFF) beams: comparison of diode, film and scintillation dosimeters. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)32371-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Warrener K, Liu P, Ralston A, McKenzie D, Suchowerska N. PD-0231: Small field in-air output factors: miniphantom design and selection of dosimeter type. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)32537-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Liu PZY, Suchowerska N, Lambert J, Abolfathi P, McKenzie DR. Reply to the comment on: ‘Plastic scintillation dosimetry: comparison of three solutions for the Cerenkov challenge’. Phys Med Biol 2012. [DOI: 10.1088/0031-9155/57/11/3667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bewes JM, Suchowerska N, Cartwright L, Ebert MA, McKenzie DR. Optimization of temporal dose modulation: Comparison of theory and experiment. Med Phys 2012; 39:3181-8. [DOI: 10.1118/1.4712223] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Liu P, Suchowerska N, Naseri P, McKenzie D. PD-0035 ARRAY DOSIMETRY CUSTOMIZED FOR STEREOTACTIC RADIOSURGERY: SQUARE AIR CORE LIGHT GUIDE TECHNOLOGY. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)70374-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Liu PZY, Suchowerska N, Lambert J, Abolfathi P, McKenzie DR. Plastic scintillation dosimetry: comparison of three solutions for the Cerenkov challenge. Phys Med Biol 2011; 56:5805-21. [DOI: 10.1088/0031-9155/56/18/003] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Potter MDE, Suchowerska N, Rizvi S, McKenzie DR. Hidden stressors in the clonogenic assay used in radiobiology experiments. Australas Phys Eng Sci Med 2011; 34:345-50. [PMID: 21691851 DOI: 10.1007/s13246-011-0082-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 06/06/2011] [Indexed: 10/18/2022]
Abstract
While clonogenic assays are extensively used in radiobiology, there is no widely accepted procedure for choosing the composition of the cell culture media. Cell line suppliers recommend a specific culture medium for each cell line, however a researcher will frequently customize this aspect of the protocol by supplementing the recommended support medium with additives. For example, many researchers add antibiotics, in order to avoid contamination of cells and the consequent loss of data, with little discussion of the influence of the antibiotics on the clonogenic survival of the cells. It is assumed that the effect of any variables in the growth medium on cell survival is taken into consideration by comparing the survival fraction relative to that of controls grown under the same conditions. In the search for better cancer treatment, the effect of various stressors on clonogenic cell survival is under investigation. This study seeks to identify and test potential stressors commonly introduced into the cell culture medium, which may confound the response to radiation.
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Affiliation(s)
- M D E Potter
- Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
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Warrener K, Ralslon A, Liu P, McKenzie D, Suchowerska N. 373 oral COMPARISON OF DIODE, DIAMOND AND SCINTILLATION DETECTORS FOR THE MEASUREMENT OF SMALL FIELD OUTPUT FACTORS. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)70495-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Suchowerska N, Rizvi S, Taychasiraprapakul A, Atyeo J, Ebert M, McKenzie D. 1510 poster FACTORS AFFECTING THE TIME COURSE OF BYSTANDER EXPRESSION. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)71632-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Liu P, Suchowerska N, Abolfathi P, Wilkins R, McKenzie D. 107 oral SCINTILLATION DOSIMETRY IN EXTERNAL BEAM RADIATION THERAPY: REVIEW AND COMPARATIVE ANALYSIS OF THREE APPROACHES. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)70230-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Herrid M, Davey R, Stockwell S, Olejnik J, Schmoelzl S, Suchowerska N, Jackson M, Holland M, Hill JR. A shorter interval between irradiation of recipient testis and germ cell transplantation is detrimental to recovery of fertility in rams. ACTA ACUST UNITED AC 2010; 34:501-12. [PMID: 21447118 DOI: 10.1111/j.1365-2605.2010.01113.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The objective of the current study was to identify an optimal time period for donor cell transplantation after irradiation in sheep. The testes of recipient rams were treated with a single dose of 15 Gray (Gy) irradiation followed by germ cell transplantation either 3 or 6 weeks later. Transplantation of donor cells at 6 weeks after irradiation resulted in production of donor sperm by all five recipient rams compared with 4 of 11 rams transplanted at 3 weeks. Rams transplanted 3 weeks post-irradiation appeared to show reduced libido and fertility. Two rams produced sperm with low motility (< 20%) and two other rams were azoospermic. More than 1 year after cell transfer, there were heavy infiltrates of CD45-positive cells and more fibrous tissue in 9 of 14 recipient testes (seven rams) that received cells 3 weeks after irradiation. Taken together, these results suggest that the interval between irradiation of recipients and germ cell transplantation affects the success rate of the procedure, with a 6-week interval preferable. The elevated inflammatory/immune reaction may be responsible, at least in part, for the reduced fertility and low libido observed in the rams that received cells 3 weeks post-irradiation.
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Affiliation(s)
- M Herrid
- CSIRO Food Futures National Research Flagship, Sydney, NSW, Australia.
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Cartwright LE, Suchowerska N, Yin Y, Lambert J, Haque M, McKenzie DR. Dose mapping of the rectal wall during brachytherapy with an array of scintillation dosimeters. Med Phys 2010; 37:2247-55. [DOI: 10.1118/1.3397446] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Miller J, Fuller M, Vinod S, Suchowerska N, Holloway L. The significance of the choice of radiobiological (NTCP) models in treatment plan objective functions. Australas Phys Eng Sci Med 2009; 32:81-7. [PMID: 19623858 DOI: 10.1007/bf03178632] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A Clinician's discrimination between radiation therapy treatment plans is traditionally a subjective process, based on experience and existing protocols. A more objective and quantitative approach to distinguish between treatment plans is to use radiobiological or dosimetric objective functions, based on radiobiological or dosimetric models. The efficacy of models is not well understood, nor is the correlation of the rank of plans resulting from the use of models compared to the traditional subjective approach. One such radiobiological model is the Normal Tissue Complication Probability (NTCP). Dosimetric models or indicators are more accepted in clinical practice. In this study, three radiobiological models, Lyman NTCP, critical volume NTCP and relative seriality NTCP, and three dosimetric models, Mean Lung Dose (MLD) and the Lung volumes irradiated at 10Gy (V10) and 20Gy (V20), were used to rank a series of treatment plans using, harm to normal (Lung) tissue as the objective criterion. None of the models considered in this study showed consistent correlation with the Radiation Oncologists plan ranking. If radiobiological or dosimetric models are to be used in objective functions for lung treatments, based on this study it is recommended that the Lyman NTCP model be used because it will provide most consistency with traditional clinician ranking.
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Affiliation(s)
- J Miller
- Department of Radiation Oncology, Liverpool and Macarthur Cancer, Therapy Centres, Australia.
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Suchowerska N, Bewes J, McKenzie D, Ebert M. EXPERIMENTAL CONFIRMATION OF THE INFLUENCE OF TEMPORAL INTRA-FRACTIONAL PATTERN OF DOSE DELIVERY ON THE RADIOBIOLOGICAL OUTCOME. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)73238-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Cartwright L, Nagory M, McKenzie D, Suchowerska N. A BRACHYTHERAPY IN VIVO SCINTILLATION DOSIMETER FOR QUALITY ASSURANCE: THEORETICAL AND EXPERIMENTAL EVALUATION OF ANGULAR DEPENDENCE. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)72794-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Yin Y, Lambert J, Yang S, McKenzie DR, Jackson M, Suchowerska N. A self-checking fiber optic dosimeter for monitoring common errors in brachytherapy applications. Med Phys 2009; 36:2985-91. [DOI: 10.1118/1.3132406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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38
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Cartwright LE, Lambert J, McKenzie DR, Suchowerska N. The angular dependence and effective point of measurement of a cylindrical scintillation dosimeter with and without a radio-opaque marker for brachytherapy. Phys Med Biol 2009; 54:2217-27. [DOI: 10.1088/0031-9155/54/7/024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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39
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Claridge Mackonis E, Suchowerska N, McKenzie DR, Ebert M, Jackson M, Morrell S, Bewes J. Reply to ‘Comments on “Cellular response to modulated radiation fields”’. Phys Med Biol 2009. [DOI: 10.1088/0031-9155/54/5/l03] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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40
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Bewes JM, Suchowerska N, McKenzie DR. Automated cell colony counting and analysis using the circular Hough image transform algorithm (CHiTA). Phys Med Biol 2008; 53:5991-6008. [PMID: 18836215 DOI: 10.1088/0031-9155/53/21/007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We present an automated cell colony counting method that is flexible, robust and capable of providing more in-depth clonogenic analysis than existing manual and automated approaches. The full form of the Hough transform without approximation has been implemented, for the first time. Improvements in computing speed have facilitated this approach. Colony identification was achieved by pre-processing the raw images of the colonies in situ in the flask, including images of the flask edges, by erosion, dilation and Gaussian smoothing processes. Colony edges were then identified by intensity gradient field discrimination. Our technique eliminates the need for specialized hardware for image capture and enables the use of a standard desktop scanner for distortion-free image acquisition. Additional parameters evaluated included regional colony counts, average colony area, nearest neighbour distances and radial distribution. This spatial and qualitative information extends the utility of the clonogenic assay, allowing analysis of spatially-variant cytotoxic effects. To test the automated system, two flask types and three cell lines with different morphology, cell size and plating density were examined. A novel Monte Carlo method of simulating cell colony images, as well as manual counting, were used to quantify algorithm accuracy. The method was able to identify colonies with unusual morphology, to successfully resolve merged colonies and to correctly count colonies adjacent to flask edges.
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Affiliation(s)
- J M Bewes
- School of Physics, University of Sydney, Sydney, NSW, Australia.
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41
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McKenzie D, Suchowerska N, Lambert J, Law S. Cerenkov-free Scintillation Dosimeter for use in External Beam Radiotherapy. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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42
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Suchowerska N, Ebert M, McKenzie D, Jackson M, Milross C. The Radiobiology of Modulated Radiotherapy: Experimental Evidence and Models for Tumour Response. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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43
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Bewes JM, Suchowerska N, Jackson M, Zhang M, McKenzie DR. The radiobiological effect of intra-fraction dose-rate modulation in intensity modulated radiation therapy (IMRT). Phys Med Biol 2008; 53:3567-78. [DOI: 10.1088/0031-9155/53/13/012] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lambert J, Yin Y, McKenzie DR, Law S, Suchowerska N. Cerenkov-free scintillation dosimetry in external beam radiotherapy with an air core light guide. Phys Med Biol 2008; 53:3071-80. [DOI: 10.1088/0031-9155/53/11/021] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Yin Y, Lambert J, McKenzie DR, Suchowerska N. Real-time monitoring and diagnosis of scintillation dosimeters using an ultraviolet light emitting diode. Phys Med Biol 2008; 53:2303-12. [DOI: 10.1088/0031-9155/53/9/007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Herrid M, Jackson M, Suchowerska N, Stockwell S, Hutton K, Davey R, Olejnik J, Hope S, Hill JR. 251. Production of donor-derived live lambs following testis germ cell transplantation. Reprod Fertil Dev 2008. [DOI: 10.1071/srb08abs251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Testes germ cell transplantation in livestock has the potential for amplification of transgenic genotypes and for use as an alternative to artificial insemination. This study investigated a workable protocol for testis germ cell transplantation in sheep between animals of the same breed and different breeds. Testes of two groups of recipients at the stage of pre-pubertal (transition from gonocytes to spermatogonia, n = 2) or peri-pubertal (spermatogenesis initiated, n = 2) were treated with a single dose of 9 grey (Gy) or 15 Gy with a 6MV photon beam irradiation, respectively. In the first experiment, using pre-pubertal irradiated animals, testis germ cell transplantation between the same breed was performed at 16 weeks post irradiation. The left testes of recipient rams were injected with donor cells labelled with fluorescent dye PHK26, while the right testes were given unlabelled cells. The left testes of recipients were removed by castration after 2 weeks following transplantation to evaluate the location of the transferred cells, while the right testes were kept in place for long-term assessment of sperm output. In cryosections of the left testes, PKH26 positive cells were found both on the basement membrane as single cells or in the interstitial area. In the second experiment, animals irradiated at the peri-pubertal stage, received donor cells at 5 weeks post irradiation and animals were kept intact for semen production. For a period of two years after transplantation, semen samples were collected routinely from two groups of rams and analysed using microsatellite markers. Two recipients (50%) demonstrated the presence of donor DNA in their ejaculates. In order to investigate the fertility of the donor-origin sperm in recipient ejaculates, 99 ewes were artificially inseminated with semen from two positive rams. Four lambs (8%) have been identified as being sired by donor-derived sperm produced in the recipient ram that received a Merino to Merino transplantation, while no donor-derived offspring was obtained from the recipient with Border Leicester to Merino transplantation. This study represents the first report of the production of live progeny following testis germ cell transplantation in sheep.
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Best S, Ralston A, McKenzie D, Suchowerska N. Effect of scatter material on diode detector performance forin vivodosimetry. Phys Med Biol 2007; 53:89-97. [DOI: 10.1088/0031-9155/53/1/006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Cell survival following exposure to spatially modulated beams, as created by intensity-modulated radiotherapy (IMRT), is investigated. In vitro experiments were performed using malignant melanoma cells (MM576) exposed to a therapeutic megavoltage photon beam. We compared cell survival in modulated fields with cell survival in uniform control fields. Three different spatial modulations of the field were used: a control 'uniform' field in which all cells in a flask were uniformly exposed; a 'quarter' field in which 25% of cells at one end of the flask were exposed and a 'striped' field in which 25% of cells were exposed in three parallel stripes. The cell survival in both the shielded and unshielded regions of the modulated fields, as determined by a clonogenic assay, were compared to the cell survival in the uniform field. We have distinguished three ways in which cell survival is influenced by the fate of neighbouring cells. The first of these (type I effect) is the previously reported classical Bystander effect, where cell survival is reduced when communicating with irradiated cells. We find two new types of Bystander effect. The type II effect is an observed increase in cell survival when nearby cells receive a lethal dose. The type III effect is an increase in the survival of cells receiving a high dose of radiation, when nearby cells receive a low dose. These observations of the Bystander effects emphasize the need for improved radiobiological models, which include communicated effects and account for the effects of modulated dose distribution.
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Affiliation(s)
- E Claridge Mackonis
- Department of Radiation Oncology, Royal Prince Alfred Hospital, Sydney, Camperdown 2050, NSW, Australia
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Claridge E, Suchowerska N, Zhang M, Ebert M, McKenzie D, Jackson M. WE-D-M100J-08: Cellular Response to Modulated Radiation Fields. Med Phys 2007. [DOI: 10.1118/1.2761569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Abstract
Cerenkov radiation is generated as an unwanted background when optical fibers carrying signals pass through radiation fields. The angular dependence of the intensity of ? Cerenkov radiation transmitted in silica-core fibers was measured using 6 and 12 MeV electron beams from a Varian Clinic accelerator. These confirmed theoretical predictions that the angular variation of ? Cerenkov radiation transmitted along optical fibers depends only on the refractive index difference Dn between the core and the cladding, and that the peak intensity is proportional to the cube of the fiber core radius.
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Affiliation(s)
- S H Law
- Optical Fibre Technology Centre and School of Physics, University of Sydney, New South Wales, Australia.
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