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Tadepalli S, Clements DR, Saravanan S, Hornero RA, Lüdtke A, Blackmore B, Paulo JA, Gottfried-Blackmore A, Seong D, Park S, Chan L, Kopecky BJ, Liu Z, Ginhoux F, Lavine KJ, Murphy JP, Mack M, Graves EE, Idoyaga J. Rapid recruitment and IFN-I-mediated activation of monocytes dictate focal radiotherapy efficacy. Sci Immunol 2023; 8:eadd7446. [PMID: 37294749 PMCID: PMC10340791 DOI: 10.1126/sciimmunol.add7446] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 05/18/2023] [Indexed: 06/11/2023]
Abstract
The recruitment of monocytes and their differentiation into immunosuppressive cells is associated with the low efficacy of preclinical nonconformal radiotherapy (RT) for tumors. However, nonconformal RT (non-CRT) does not mimic clinical practice, and little is known about the role of monocytes after RT modes used in patients, such as conformal RT (CRT). Here, we investigated the acute immune response induced by after CRT. Contrary to non-CRT approaches, we found that CRT induces a rapid and robust recruitment of monocytes to the tumor that minimally differentiate into tumor-associated macrophages or dendritic cells but instead up-regulate major histocompatibility complex II and costimulatory molecules. We found that these large numbers of infiltrating monocytes are responsible for activating effector polyfunctional CD8+ tumor-infiltrating lymphocytes that reduce tumor burden. Mechanistically, we show that monocyte-derived type I interferon is pivotal in promoting monocyte accumulation and immunostimulatory function in a positive feedback loop. We also demonstrate that monocyte accumulation in the tumor microenvironment is hindered when RT inadvertently affects healthy tissues, as occurs in non-CRT. Our results unravel the immunostimulatory function of monocytes during clinically relevant modes of RT and demonstrate that limiting the exposure of healthy tissues to radiation has a positive therapeutic effect on the overall antitumor immune response.
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Affiliation(s)
- Sirimuvva Tadepalli
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Derek R. Clements
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Sanjana Saravanan
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Rebeca Arroyo Hornero
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Anja Lüdtke
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Beau Blackmore
- Department of Biology, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Joao A. Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Andres Gottfried-Blackmore
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Redwood City, CA 94063, USA
| | - David Seong
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
- Medical Scientist Training Program, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
| | - Soyoon Park
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Leslie Chan
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Benjamin J. Kopecky
- Center for Cardiovascular Research, Departmental of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhaoyuan Liu
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Florent Ginhoux
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Institut Gustave Roussy, INSERM U1015, Bâtiment de Médecine Moléculaire, Villejuif 94800, France
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore 138648, Republic of Singapore
| | - Kory J. Lavine
- Center for Cardiovascular Research, Departmental of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - John Patrick Murphy
- Department of Biology, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Matthias Mack
- Department of Nephrology, University Hospital Regensburg, Regensburg 93053, Germany
| | - Edward E. Graves
- Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
| | - Juliana Idoyaga
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5101, USA
- Immunology Program, Stanford University School of Medicine, Stanford, CA 94304, USA
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Kampfer S, Dobiasch S, Combs SE, Wilkens JJ. Development of a PTV margin for preclinical irradiation of orthotopic pancreatic tumors derived from a well-known recipe for humans. Z Med Phys 2023:S0939-3889(23)00042-9. [PMID: 37225604 DOI: 10.1016/j.zemedi.2023.03.005] [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: 12/19/2022] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 05/26/2023]
Abstract
In human radiotherapy a safety margin (PTV margin) is essential for successful irradiation and is usually part of clinical treatment planning. In preclinical radiotherapy research with small animals, most uncertainties and inaccuracies are present as well, but according to the literature a margin is used only scarcely. In addition, there is only little experience about the appropriate size of the margin, which should carefully be investigated and considered, since sparing of organs at risk or normal tissue is affected. Here we estimate the needed margin for preclinical irradiation by adapting a well-known human margin recipe from van Herck et al. to the dimensions and requirements of the specimen on a small animal radiation research platform (SARRP). We adjusted the factors of the described formula to the specific challenges in an orthotopic pancreatic tumor mouse model to establish an appropriate margin concept. The SARRP was used with its image-guidance irradiation possibility for arc irradiation with a field size of 10 × 10 mm2 for 5 fractions. Our goal was to irradiate the clinical target volume (CTV) of at least 90% of our mice with at least 95% of the prescribed dose. By carefully analyzing all relevant factors we gain a CTV to planning target volume (PTV) margin of 1.5 mm for our preclinical setup. The stated safety margin is strongly dependent on the exact setting of the experiment and has to be adjusted for other experimental settings. The few stated values in literature correspond well to our result. Even if using margins in the preclinical setting might be an additional challenge, we think it is crucial to use them to produce reliable results and improve the efficacy of radiotherapy.
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Affiliation(s)
- Severin Kampfer
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich (TUM), Munich, Germany; Physics Department, Technical University of Munich (TUM), Garching, Germany.
| | - Sophie Dobiasch
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich (TUM), Munich, Germany; Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, Germany.
| | - Stephanie E Combs
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich (TUM), Munich, Germany; Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, Germany; German Cancer Consortium (DKTK), Partner Site Munich, Germany.
| | - Jan J Wilkens
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich (TUM), Munich, Germany; Physics Department, Technical University of Munich (TUM), Garching, Germany; Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, Germany.
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3
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Grahm Valadie O, Brown SL, Farmer K, Nagaraja TN, Cabral G, Shadaia S, Divine GW, Knight RA, Lee IY, Dolan J, Rusu S, Joiner MC, Ewing JR. Characterization of the Response of 9L and U-251N Orthotopic Brain Tumors to 3D Conformal Radiation Therapy. Radiat Res 2023; 199:217-228. [PMID: 36656561 PMCID: PMC10174721 DOI: 10.1667/rade-22-00048.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 12/21/2022] [Indexed: 01/20/2023]
Abstract
In a study employing MRI-guided stereotactic radiotherapy (SRS) in two orthotopic rodent brain tumor models, the radiation dose yielding 50% survival (the TCD50) was sought. Syngeneic 9L cells, or human U-251N cells, were implanted stereotactically in 136 Fischer 344 rats or 98 RNU athymic rats, respectively. At approximately 7 days after implantation for 9L, and 18 days for U-251N, rats were imaged with contrast-enhanced MRI (CE-MRI) and then irradiated using a Small Animal Radiation Research Platform (SARRP) operating at 220 kV and 13 mA with an effective energy of ∼70 keV and dose rate of ∼2.5 Gy per min. Radiation doses were delivered as single fractions. Cone-beam CT images were acquired before irradiation, and tumor volumes were defined using co-registered CE-MRI images. Treatment planning using MuriPlan software defined four non-coplanar arcs with an identical isocenter, subsequently accomplished by the SARRP. Thus, the treatment workflow emulated that of current clinical practice. The study endpoint was animal survival to 200 days. The TCD50 inferred from Kaplan-Meier survival estimation was approximately 25 Gy for 9L tumors and below 20 Gy, but within the 95% confidence interval in U-251N tumors. Cox proportional-hazards modeling did not suggest an effect of sex, with the caveat of wide confidence intervals. Having identified the radiation dose at which approximately half of a group of animals was cured, the biological parameters that accompany radiation response can be examined.
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Affiliation(s)
- O. Grahm Valadie
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
- Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan
| | - Stephen L. Brown
- Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan
- Department of Radiology, Michigan State University College of Human Medicine, East Lansing, Michigan
| | - Katelynn Farmer
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
| | | | - Glauber Cabral
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
| | - Sheldon Shadaia
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
| | - George W. Divine
- Department of Public Health Sciences, Henry Ford Hospital, Detroit Michigan
| | - Robert A. Knight
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
- Department of Physics, Oakland University, Rochester, Michigan
| | - Ian Y. Lee
- Department of Neurosurgery, Henry Ford Hospital, Detroit Michigan
| | - Jennifer Dolan
- Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan
| | - Sam Rusu
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
| | - Michael C. Joiner
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan
| | - James R. Ewing
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
- Department of Radiology, Michigan State University College of Human Medicine, East Lansing, Michigan
- Department of Neurosurgery, Henry Ford Hospital, Detroit Michigan
- Department of Physics, Oakland University, Rochester, Michigan
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Entezam A, Fielding A, Bradley D, Fontanarosa D. Absorbed dose calculation for a realistic CT-derived mouse phantom irradiated with a standard Cs-137 cell irradiator using a Monte Carlo method. PLoS One 2023; 18:e0280765. [PMID: 36730280 PMCID: PMC9928120 DOI: 10.1371/journal.pone.0280765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 01/07/2023] [Indexed: 02/03/2023] Open
Abstract
Computed tomography (CT) derived Monte Carlo (MC) phantoms allow dose determination within small animal models that is not feasible with in-vivo dosimetry. The aim of this study was to develop a CT-derived MC phantom generated from a mouse with a xenograft tumour that could then be used to calculate both the dose heterogeneity in the tumour volume and out of field scattered dose for pre-clinical small animal irradiation experiments. A BEAMnrc Monte-Carlo model has been built of our irradiation system that comprises a lead collimator with a 1 cm diameter aperture fitted to a Cs-137 gamma irradiator. The MC model of the irradiation system was validated by comparing the calculated dose results with dosimetric film measurement in a polymethyl methacrylate (PMMA) phantom using a 1D gamma-index analysis. Dose distributions in the MC mouse phantom were calculated and visualized on the CT-image data. Dose volume histograms (DVHs) were generated for the tumour and organs at risk (OARs). The effect of the xenographic tumour volume on the scattered out of field dose was also investigated. The defined gamma index analysis criteria were met, indicating that our MC simulation is a valid model for MC mouse phantom dose calculations. MC dose calculations showed a maximum out of field dose to the mouse of 7% of Dmax. Absorbed dose to the tumour varies in the range 60%-100% of Dmax. DVH analysis demonstrated that tumour received an inhomogeneous dose of 12 Gy-20 Gy (for 20 Gy prescribed dose) while out of field doses to all OARs were minimized (1.29 Gy-1.38 Gy). Variation of the xenographic tumour volume exhibited no significant effect on the out of field scattered dose to OARs. The CT derived MC mouse model presented here is a useful tool for tumour dose verifications as well as investigating the doses to normal tissue (in out of field) for preclinical radiobiological research.
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Affiliation(s)
- Amir Entezam
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Centre for Biomedical Technologies, Queensland University of Technology, Brisbane, QLD, Australia
- Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
- * E-mail:
| | - Andrew Fielding
- Centre for Biomedical Technologies, Queensland University of Technology, Brisbane, QLD, Australia
- School of Chemistry and Physics, Faculty of Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - David Bradley
- Centre for Applied Physics and Radiation Technologies, Sunway University, PJ, Malaysia
- Department of Physics, University of Surrey, Guildford, United Kingdom
| | - Davide Fontanarosa
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Centre for Biomedical Technologies, Queensland University of Technology, Brisbane, QLD, Australia
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Mahuvava C, Esplen NM, Poirier Y, Kry SF, Bazalova-Carter M. Dose calculations for pre-clinical radiobiology experiments conducted with single-field cabinet irradiators. Med Phys 2022; 49:1911-1923. [PMID: 35066889 DOI: 10.1002/mp.15487] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 11/10/2021] [Accepted: 12/21/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To provide percentage depth-dose (PDD) data along the central axis for dosimetry calculations in small-animal radiation biology experiments performed in cabinet irradiators. The PDDs are provided as a function of source-to-surface distance (SSD), field size and animal size. METHODS The X-ray tube designs for four biological cabinet irradiators, the RS2000, RT250, MultiRad350 and XRAD320, were simulated using the BEAMnrc Monte Carlo code to generate 160, 200, 250 and 320 kVp photon beams, respectively. The 320 kVp beam was simulated with two filtrations: a soft F1 aluminium filter and a hard F2 thoraeus filter made of aluminium, tin and copper. Beams were collimated into circular fields with diameters of 0.5 - 10 cm at SSDs of 10 - 60 cm. Monte Carlo dose calculations in 1 - 5-cm diameter homogeneous (soft tissue) small-animal phantoms as well as in heterogeneous phantoms with 3-mm diameter cylindrical lung and bone inserts (rib and cortical bone) were performed using DOSXYZnrc. The calculated depth doses in three test-cases were estimated by applying SSD, field size and animal size correction factors to a reference case (40 cm SSD, 1 cm field and 5 cm animal size) and these results were compared with the specifically simulated (i.e., expected) doses to assess the accuracy of this method. Dosimetry for two test-case scenarios of 160 and 250 kVp beams (representative of end-user beam qualities) was also performed, whereby the simulated PDDs at two different depths were compared with the results based on the interpolation from reference data. RESULTS The depth doses for three test-cases calculated at 200, 320 kVp F1 and 320 kVp F2, with half value layers (HVL) ranging from ∼0.6 mm to 3.6 mm Cu, agreed well with the expected doses, yielding dose differences of 1.2, 0.1 and 1.0%, respectively. The two end-user test-cases for 160 and 250 kVp beams with respective HVLs of ∼0.8 and 1.8 mm Cu yielded dose differences of 1.4 and 3.2% between the simulated and the interpolated PDDs. The dose increase at the bone-tissue proximal interface ranged from 1.2 to 2.5 times the dose in soft tissue for rib and 1.3 to 3.7 times for cortical bone. The dose drop-off at 1-cm depth beyond the bone ranged from 1.3 - 6.0% for rib and 3.2 - 11.7% for cortical bone. No drastic dose perturbations occurred in the presence of lung, with lung-tissue interface dose of >99% of soft tissue dose and <3% dose increase at 1-cm depth beyond lung. CONCLUSIONS The developed dose estimation method can be used to translate the measured dose at a point to dose at any depth in small-animal phantoms, making it feasible for pre-clinical calculation of dose distributions in animals irradiated with cabinet-style irradiators. The dosimetric impact of bone must be accurately quantified as dramatic dose perturbations at and beyond the bone interfaces can occur due to the relative importance of the photoelectric effect at kilovoltage energies. These results will help improve dosimetric accuracy in pre-clinical experiments. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Courage Mahuvava
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
| | - Nolan Matthew Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
| | - Yannick Poirier
- Department of Medical Physics, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Stephen F Kry
- Department of Radiation Physics, University of Texas MD Anderson, Cancer Centre, Houston, TX, 77030, USA
| | - Magdalena Bazalova-Carter
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
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Robinson SM, Esplen N, Wells D, Bazalova-Carter M. Monte Carlo simulations of EBT3 film dose deposition for percentage depth dose (PDD) curve evaluation. J Appl Clin Med Phys 2020; 21:314-324. [PMID: 33155768 PMCID: PMC7769387 DOI: 10.1002/acm2.13078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/04/2020] [Accepted: 10/05/2020] [Indexed: 02/04/2023] Open
Abstract
Purpose To use Monte Carlo (MC) calculations to evaluate the effects of Gafchromic EBT3 film orientation on percentage depth dose (PDD) curves. Methods Dose deposition in films placed in a water phantom, and oriented either parallel or perpendicular with respect to beam axis, were simulated with MC and compared to PDDs scored in a homogenous water phantom. The effects of introducing 0.01–1.00 mm air gaps on each side of the film as well as a small 1°‐3° tilt for film placed in parallel orientation were studied. PDDs scored based on two published EBT3 film compositions were compared. Three photon beam energies of 120 kVp, 220 kVp, and 6 MV and three field sizes between 1 × 1 and 5 × 5 cm2 were considered. Experimental PDDs for a 6‐MV 3 × 3 cm2 beam were acquired. Results PDD curves for films in perpendicular orientation more closely agreed to water PDDs than films placed in parallel orientation. The maximum difference between film and water PDD for films in parallel orientation was −12.9% for the 220 kVp beam. For the perpendicular film orientation, the maximum difference decreased to 5.7% for the 120 kVp beam. The inclusion of an air gap had the largest effect on the 6‐MV 1 × 1 cm2 beam, for which the dose in the buildup region was underestimated by 21.2% compared to the simulation with no air gap. A 2° film tilt decreased the difference between the parallel film and homogeneous water phantom PDDs from −5.0% to −0.5% for the 6 MV 3 × 3 cm2 beam. The “newer” EBT3 film composition resulted in larger PDD discrepancies than the previous composition. Experimental film data qualitatively agreed with MC simulations. Conclusions PDD measurements with films should either be performed with film in perpendicular orientation to the beam axis or in parallel orientation with a ~ 2º tilt and no air gaps.
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Affiliation(s)
- Spencer M Robinson
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Nolan Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Derek Wells
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada.,BC Cancer Vancouver Island Centre, Victoria, BC, Canada
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Feasibility study of the Fricke chemical dosimeter as an independent dosimetric system for the small animal radiation research platform (SARRP). Phys Med 2020; 71:168-175. [DOI: 10.1016/j.ejmp.2020.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/13/2022] Open
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Schlaak RA, SenthilKumar G, Boerma M, Bergom C. Advances in Preclinical Research Models of Radiation-Induced Cardiac Toxicity. Cancers (Basel) 2020; 12:E415. [PMID: 32053873 PMCID: PMC7072196 DOI: 10.3390/cancers12020415] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/08/2020] [Accepted: 02/08/2020] [Indexed: 12/12/2022] Open
Abstract
Radiation therapy (RT) is an important component of cancer therapy, with >50% of cancer patients receiving RT. As the number of cancer survivors increases, the short- and long-term side effects of cancer therapy are of growing concern. Side effects of RT for thoracic tumors, notably cardiac and pulmonary toxicities, can cause morbidity and mortality in long-term cancer survivors. An understanding of the biological pathways and mechanisms involved in normal tissue toxicity from RT will improve future cancer treatments by reducing the risk of long-term side effects. Many of these mechanistic studies are performed in animal models of radiation exposure. In this area of research, the use of small animal image-guided RT with treatment planning systems that allow more accurate dose determination has the potential to revolutionize knowledge of clinically relevant tumor and normal tissue radiobiology. However, there are still a number of challenges to overcome to optimize such radiation delivery, including dose verification and calibration, determination of doses received by adjacent normal tissues that can affect outcomes, and motion management and identifying variation in doses due to animal heterogeneity. In addition, recent studies have begun to determine how animal strain and sex affect normal tissue radiation injuries. This review article discusses the known and potential benefits and caveats of newer technologies and methods used for small animal radiation delivery, as well as how the choice of animal models, including variables such as species, strain, and age, can alter the severity of cardiac radiation toxicities and impact their clinical relevance.
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Affiliation(s)
- Rachel A. Schlaak
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
| | - Gopika SenthilKumar
- Medical Scientist Training Program, Medical College of Wisconsin; Milwaukee, WI 53226, USA;
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, The University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
| | - Carmen Bergom
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cancer Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Muñoz Arango E, Peixoto JG, de Almeida CE. Small-field dosimetry with a high-resolution 3D scanning water phantom system for the small animal radiation research platform SARRP: a geometrical and quantitative study. ACTA ACUST UNITED AC 2020; 65:015012. [DOI: 10.1088/1361-6560/ab5c47] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Breitkreutz DY, Bialek S, Vojnovic B, Kavanagh A, Johnstone CD, Rovner Z, Tsouchlos P, Kanesalingam T, Bazalova-Carter M. A 3D printed modular phantom for quality assurance of image-guided small animal irradiators: Design, imaging experiments, and Monte Carlo simulations. Med Phys 2019; 46:2015-2024. [PMID: 30947359 DOI: 10.1002/mp.13525] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/25/2019] [Accepted: 03/25/2019] [Indexed: 01/21/2023] Open
Abstract
PURPOSE The goal of this work was to develop and test a cylindrical tissue-equivalent quality assurance (QA) phantom for micro computed tomography (microCT) image-guided small animal irradiators that overcomes deficiencies of existing phantoms due to its mouse-like dimensions and composition. METHODS The 8.6-cm-long and 2.4-cm-diameter phantom was three-dimensionally (3D) printed out of Somos NeXt plastic on a stereolithography (SLA) printer. The modular phantom consisted of four sections: (a) CT number evaluation section, (b) spatial resolution with slanted edge (for the assessment of longitudinal resolution) and targeting section, (c) spatial resolution with hole pattern (for the assessment of radial direction) section, and (d) uniformity and geometry section. A Python-based graphical user interface (GUI) was developed for automated analysis of microCT images and evaluated CT number consistency, longitudinal and radial modulation transfer function (MTF), image uniformity, noise, and geometric accuracy. The phantom was placed at the imaging isocenter and scanned with the small animal radiation research platform (SARRP) in the pancake geometry (long axis of the phantom perpendicular to the axis of rotation) with a variety of imaging protocols. Tube voltage was set to 60 and 70 kV, tube current was set to 0.5 and 1.2 mA, voxel size was set to 200 and 275 μm, imaging times of 1, 2, and 4 min were used, and frame rates of 6 and 12 frames per second (fps) were used. The phantom was also scanned in the standard (long axis of the phantom parallel to the axis of rotation) orientation. The quality of microCT images was analyzed and compared to recommendations presented in our previous work that was derived from a multi-institutional study. Additionally, a targeting accuracy test with a film placed in the phantom was performed. MicroCT imaging of the phantom was also simulated in a modified version of the EGSnrc/DOSXYZnrc code. Images of the resolution section with the hole pattern were acquired experimentally as well as simulated in both the pancake and the standard imaging geometries. The radial spatial resolution of the experimental and simulated images was evaluated and compared to experimental data. RESULTS For the centered phantom images acquired in the pancake geometry, all imaging protocols passed the spatial resolution criterion in the radial direction (>1.5 lp/mm @ 0.2 MTF), the geometric accuracy criterion (<200 μm), and the noise criterion (<55 HU). Only the imaging protocol with 200-μm voxel size passed the criterion for spatial resolution in the longitudinal direction (>1.5 lp/mm @ 0.2 MTF). The 70-kV tube voltage dataset failed the bone CT number consistency test (<55 HU). Due to cupping artifacts, none of the imaging protocols passed the uniformity test of <55 HU. When the phantom was scanned in the standard imaging geometry, image uniformity and longitudinal MTF were satisfactory; however, the CT number consistency failed the recommended limit. A targeting accuracy of 282 and 251 μm along the x- and z-direction was observed. Monte Carlo simulations confirmed that the radial spatial resolution for images acquired in the pancake geometry was higher than the one acquired in the standard geometry. CONCLUSIONS The new 3D-printed phantom presents a useful tool for microCT image analysis as it closely mimics a mouse. In order to image mouse-sized animals with acceptable image quality, the standard protocol with a 200-μm voxel size should be chosen and cupping artifacts need to be resolved.
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Affiliation(s)
| | - Spencer Bialek
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Boris Vojnovic
- Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Anthony Kavanagh
- Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
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11
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Grover AR, Kimler BF, Duncan FE. Use of a Small Animal Radiation Research Platform (SARRP) facilitates analysis of systemic versus targeted radiation effects in the mouse ovary. J Ovarian Res 2018; 11:72. [PMID: 30165884 PMCID: PMC6116356 DOI: 10.1186/s13048-018-0442-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 08/12/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Radiation exposure is known to cause accelerated aging and damage to the ovary, but the contribution of indirect versus direct effects is not well understood. We used the Small Animal Radiation Research Platform (SARRP) (Xstrahl) to deliver radiation to precise fields equivalent to clinical practice, allowing us to investigate systemic versus targeted damage in a structure as small as the mouse ovary. The X-ray dose was kept constant at 1 Gy, but the field varied. Mice either received total body irradiation (TBI), radiation targeted to both ovaries (T2), or radiation targeted to one ovary (left) while the contralateral ovary (right) was spared (T1). Sham mice, handled similarly to the other cohorts but not exposed to radiation, served as controls. Two weeks post-exposure, ovaries were harvested and analyzed histologically to identify and count follicles within each ovary. RESULTS Radiation significantly reduced primordial follicles in the TBI and T2 cohorts compared to the Sham cohort. There were no significant differences between these two irradiated groups. These findings suggest that at 1 Gy, the extent of damage to the ovary caused by radiation is similar despite the different delivery methods. When investigating the T1 cohort, targeted ovaries showed a significant decrease in primordial and growing follicles compared to non-targeted contralateral ovaries. CONCLUSIONS These findings demonstrate that the SARRP is an effective strategy for delivering precise ionizing radiation to small organs such as mouse ovaries. Such tools will facilitate identifying the relative risks to ovarian function associated with different radiation fields as well as screening the efficacy of emerging fertoprotective agents.
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Affiliation(s)
- Allison R Grover
- Center for Reproductive Science, Northwestern University, Chicago, IL, 60611, USA
| | - Bruce F Kimler
- Department of Radiation Oncology, Kansas University Medical Center, Kansas City, KS, 66160, USA
| | - Francesca E Duncan
- Center for Reproductive Science, Northwestern University, Chicago, IL, 60611, USA. .,Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, 303 E. Superior Street, Lurie 7-117, Chicago, IL, 60611, USA.
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12
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MRI-based high-precision irradiation in an orthotopic pancreatic tumor mouse model. Strahlenther Onkol 2018; 194:944-952. [DOI: 10.1007/s00066-018-1326-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/28/2018] [Indexed: 12/15/2022]
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13
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Stewart JMP, Stapleton S, Chaudary N, Lindsay PE, Jaffray DA. Spatial frequency performance limitations of radiation dose optimization and beam positioning. Phys Med Biol 2018; 63:125006. [PMID: 29762137 DOI: 10.1088/1361-6560/aac501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The flexibility and sophistication of modern radiotherapy treatment planning and delivery methods have advanced techniques to improve the therapeutic ratio. Contemporary dose optimization and calculation algorithms facilitate radiotherapy plans which closely conform the three-dimensional dose distribution to the target, with beam shaping devices and image guided field targeting ensuring the fidelity and accuracy of treatment delivery. Ultimately, dose distribution conformity is limited by the maximum deliverable dose gradient; shallow dose gradients challenge techniques to deliver a tumoricidal radiation dose while minimizing dose to surrounding tissue. In this work, this 'dose delivery resolution' observation is rigorously formalized for a general dose delivery model based on the superposition of dose kernel primitives. It is proven that the spatial resolution of a delivered dose is bounded by the spatial frequency content of the underlying dose kernel, which in turn defines a lower bound in the minimization of a dose optimization objective function. In addition, it is shown that this optimization is penalized by a dose deposition strategy which enforces a constant relative phase (or constant spacing) between individual radiation beams. These results are further refined to provide a direct, analytic method to estimate the dose distribution arising from the minimization of such an optimization function. The efficacy of the overall framework is demonstrated on an image guided small animal microirradiator for a set of two-dimensional hypoxia guided dose prescriptions.
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Affiliation(s)
- James M P Stewart
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada. Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
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14
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Adamson J, Mein S, Meng B, Gunasingha R, Yoon SW, Miles D, Walder H, Fathi Z, Beyer W, Spector N, Gieger TL, Nolan MW, Oldham M. Utilizing a diagnostic kV imaging system for x-ray psoralen activated cancer therapy (X-PACT). Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa6e58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Hamdi M, Mimi M, Bentourkia M. Impact of X-ray energy on absorbed dose assessed with Monte Carlo simulations in a mouse tumor and in nearest organs irradiated with kilovoltage X-ray beams. Cancer Radiother 2017; 21:190-198. [DOI: 10.1016/j.canrad.2017.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/24/2016] [Accepted: 01/09/2017] [Indexed: 02/07/2023]
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16
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Welch D, Turner L, Speiser M, Randers-Pehrson G, Brenner DJ. Scattered Dose Calculations and Measurements in a Life-Like Mouse Phantom. Radiat Res 2017; 187:433-442. [PMID: 28140787 DOI: 10.1667/rr004cc.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Anatomically accurate phantoms are useful tools for radiation dosimetry studies. In this work, we demonstrate the construction of a new generation of life-like mouse phantoms in which the methods have been generalized to be applicable to the fabrication of any small animal. The mouse phantoms, with built-in density inhomogeneity, exhibit different scattering behavior dependent on where the radiation is delivered. Computer models of the mouse phantoms and a small animal irradiation platform were devised in Monte Carlo N-Particle code (MCNP). A baseline test replicating the irradiation system in a computational model shows minimal differences from experimental results from 50 Gy down to 0.1 Gy. We observe excellent agreement between scattered dose measurements and simulation results from X-ray irradiations focused at either the lung or the abdomen within our phantoms. This study demonstrates the utility of our mouse phantoms as measurement tools with the goal of using our phantoms to verify complex computational models.
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Affiliation(s)
- David Welch
- a Center for Radiological Research, Columbia University, New York, New York
| | - Leah Turner
- a Center for Radiological Research, Columbia University, New York, New York
| | - Michael Speiser
- b Englewood Hospital and Medical Center, Englewood, New Jersey
| | | | - David J Brenner
- a Center for Radiological Research, Columbia University, New York, New York
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17
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Brodin NP, Velcich A, Guha C, Tomé WA. A Model for Precise and Uniform Pelvic- and Limb-Sparing Abdominal Irradiation to Study the Radiation-Induced Gastrointestinal Syndrome in Mice Using Small Animal Irradiation Systems. Dose Response 2017; 15:1559325816685798. [PMID: 28203121 PMCID: PMC5298432 DOI: 10.1177/1559325816685798] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background and Purpose: Currently, no readily available mitigators exist for acute abdominal radiation injury. Here, we present an animal model for precise and homogenous limb-sparing abdominal irradiation (LSAIR) to study the radiation-induced gastrointestinal syndrome (RIGS). Materials and Methods: The LSAIR technique was developed using the small animal radiation research platform (SARRP) with image guidance capabilities. We delivered LSAIR at doses between 14 and 18 Gy on 8- to 10-week-old male C57BL/6 mice. Histological analysis was performed to confirm that the observed mortality was due to acute abdominal radiation injury. Results: A steep dose–response relationship was found for survival, with no deaths seen at doses below 16 Gy and 100% mortality at above 17 Gy. All deaths occurred between 6 and 10 days after irradiation, consistent with the onset of RIGS. This was further confirmed by histological analysis showing clear differences in the number of regenerative intestinal crypts between animals receiving sublethal (14 Gy) and 100% lethal (18 Gy) radiation. Conclusion: The developed LSAIR technique provides uniform dose delivery with a clear dose response, consistent with acute abdominal radiation injury on histological examination. This model can provide a useful tool for researchers investigating the development of mitigators for accidental or clinical high-dose abdominal irradiation.
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Affiliation(s)
- N Patrik Brodin
- Department of Radiation Oncology, Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA
| | - Anna Velcich
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA
| | - Chandan Guha
- Department of Radiation Oncology, Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA
| | - Wolfgang A Tomé
- Department of Radiation Oncology, Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, USA
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18
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Reinhart AM, Fast MF, Ziegenhein P, Nill S, Oelfke U. A kernel-based dose calculation algorithm for kV photon beams with explicit handling of energy and material dependencies. Br J Radiol 2016; 90:20160426. [PMID: 27785933 PMCID: PMC5605017 DOI: 10.1259/bjr.20160426] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Objective: Mimicking state-of-the-art patient radiotherapy with high-precision irradiators for small animals is expected to advance the understanding of dose–effect relationships and radiobiology in general. We work on the implementation of intensity-modulated radiotherapy-like irradiation schemes for small animals. As a first step, we present a fast analytical dose calculation algorithm for keV photon beams. Methods: We follow a superposition–convolution approach adapted to kV X-rays, based on previous work for microbeam therapy. We assume local energy deposition at the photon interaction point due to the short electron ranges in tissue. This allows us to separate the dose calculation into locally absorbed primary dose and the scatter contribution, calculated in a point kernel approach. We validate our dose model against Geant4 Monte Carlo (MC) simulations and compare the results to Muriplan (XStrahl Ltd, Camberley, UK). Results: For field sizes of (1 mm)2 to (1 cm)2 in water, the depth dose curves show a mean disagreement of 1.7% to MC simulations, with the largest deviations in the entrance region (4%) and at large depths (5% at 7 cm). Larger discrepancies are observed at water-to-bone boundaries, in bone and at the beam edges in slab phantoms and a mouse brain. Calculation times are in the order of 5 s for a single beam. Conclusion: The algorithm shows good agreement with MC simulations in an initial validation. It has the potential to become an alternative to full MC dose calculation. Advances in knowledge: The presented algorithm demonstrates the potential of kernel-based dose calculation for kV photon beams. It will be valuable in intensity-modulated radiotherapy and inverse treatment planning for high precision small-animal radiotherapy.
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Affiliation(s)
- Anna Merle Reinhart
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - Martin F Fast
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - Peter Ziegenhein
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - Simeon Nill
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - Uwe Oelfke
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
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19
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Ford E, Deye J. Current Instrumentation and Technologies in Modern Radiobiology Research—Opportunities and Challenges. Semin Radiat Oncol 2016; 26:349-55. [DOI: 10.1016/j.semradonc.2016.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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20
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Brodin NP, Chen Y, Yaparpalvi R, Guha C, Tomé WA. Dosimetry Formalism and Implementation of a Homogenous Irradiation Protocol to Improve the Accuracy of Small Animal Whole-Body Irradiation Using a 137Cs Irradiator. HEALTH PHYSICS 2016; 110:S26-S38. [PMID: 26710162 PMCID: PMC4693616 DOI: 10.1097/hp.0000000000000462] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Shielded Cs irradiators are routinely used in pre-clinical radiation research to perform in vitro or in vivo investigations. Without appropriate dosimetry and irradiation protocols in place, there can be large uncertainty in the delivered dose of radiation between irradiated subjects that could lead to inaccurate and possibly misleading results. Here, a dosimetric evaluation of the JL Shepard Mark I-68A Cs irradiator and an irradiation technique for whole-body irradiation of small animals that allows one to limit the between subject variation in delivered dose to ±3% are provided. Mathematical simulation techniques and Gafchromic EBT film were used to describe the region within the irradiation cavity with homogeneous dose distribution (100% ± 5%), the dosimetric impact of varying source-to-subject distance, and the variation in attenuation thickness due to turntable rotation. Furthermore, an irradiation protocol and dosimetry formalism that allows calculation of irradiation time for whole-body irradiation of small animals is proposed that is designed to ensure a more consistent dose delivery between irradiated subjects. To compare this protocol with the conventional irradiation protocol suggested by the vendor, high-resolution film dosimetry measurements evaluating the dose difference between irradiation subjects and the dose distribution throughout subjects was performed using phantoms resembling small animals. Based on these results, there can be considerable variation in the delivered dose of > ± 5% using the conventional irradiation protocol for whole-body irradiation doses below 5 Gy. Using the proposed irradiation protocol this variability can be reduced to within ±3% and the dosimetry formalism allows for more accurate calculation of the irradiation time in relation to the intended prescription dose.
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Affiliation(s)
- N. Patrik Brodin
- Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yong Chen
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Ravindra Yaparpalvi
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Chandan Guha
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY 10461, USA
- Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Wolfgang A. Tomé
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY 10461, USA
- Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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21
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Brodin NP, Guha C, Tomé WA. Proposal for a Simple and Efficient Monthly Quality Management Program Assessing the Consistency of Robotic Image-Guided Small Animal Radiation Systems. HEALTH PHYSICS 2015; 109:S190-S199. [PMID: 26425981 PMCID: PMC4602164 DOI: 10.1097/hp.0000000000000323] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Modern pre-clinical radiation therapy (RT) research requires high precision and accurate dosimetry to facilitate the translation of research findings into clinical practice. Several systems are available that provide precise delivery and on-board imaging capabilities, highlighting the need for a quality management program (QMP) to ensure consistent and accurate radiation dose delivery. An ongoing, simple, and efficient QMP for image-guided robotic small animal irradiators used in pre-clinical RT research is described. Protocols were developed and implemented to assess the dose output constancy (based on the AAPM TG-61 protocol), cone-beam computed tomography (CBCT) image quality and object representation accuracy (using a custom-designed imaging phantom), CBCT-guided target localization accuracy and consistency of the CBCT-based dose calculation. To facilitate an efficient read-out and limit the user dependence of the QMP data analysis, a semi-automatic image analysis and data representation program was developed using the technical computing software MATLAB. The results of the first 6-mo experience using the suggested QMP for a Small Animal Radiation Research Platform (SARRP) are presented, with data collected on a bi-monthly basis. The dosimetric output constancy was established to be within ±1 %, the consistency of the image resolution was within ±0.2 mm, the accuracy of CBCT-guided target localization was within ±0.5 mm, and dose calculation consistency was within ±2 s (±3%) per treatment beam. Based on these results, this simple quality assurance program allows for the detection of inconsistencies in dosimetric or imaging parameters that are beyond the acceptable variability for a reliable and accurate pre-clinical RT system, on a monthly or bi-monthly basis.
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Affiliation(s)
- N. Patrik Brodin
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY 10461, USA
- Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Chandan Guha
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY 10461, USA
- Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Wolfgang A. Tomé
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY 10461, USA
- Institute for Onco-Physics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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22
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Ali R, Apte S, Vilalta M, Subbarayan M, Miao Z, Chin FT, Graves EE. 18F-EF5 PET Is Predictive of Response to Fractionated Radiotherapy in Preclinical Tumor Models. PLoS One 2015; 10:e0139425. [PMID: 26431331 PMCID: PMC4592127 DOI: 10.1371/journal.pone.0139425] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 09/14/2015] [Indexed: 12/27/2022] Open
Abstract
We evaluated the relationship between pre-treatment positron emission tomography (PET) using the hypoxic tracer 18F-[2-(2-nitro-1-H-imidazol-1-yl)-N-(2,2,3,3,3- pentafluoropropyl) acetamide] (18F-EF5) and the response of preclinical tumor models to a range of fractionated radiotherapies. Subcutaneous HT29, A549 and RKO tumors grown in nude mice were imaged using 18F-EF5 positron emission tomography (PET) in order to characterize the extent and heterogeneity of hypoxia in these systems. Based on these results, 80 A549 tumors were subsequently grown and imaged using 18F-EF5 PET, and then treated with one, two, or four fraction radiation treatments to a total dose of 10–40 Gy. Response was monitored by serial caliper measurements of tumor volume. Longitudinal post-treatment 18F-EF5 PET imaging was performed on a subset of tumors. Terminal histologic analysis was performed to validate 18F-EF5 PET measures of hypoxia. EF5-positive tumors responded more poorly to low dose single fraction irradiation relative to EF5-negative tumors, however both groups responded similarly to larger single fraction doses. Irradiated tumors exhibited reduced 18F-EF5 uptake one month after treatment compared to control tumors. These findings indicate that pre- treatment 18F-EF5 PET can predict the response of tumors to single fraction radiation treatment. However, increasing the number of fractions delivered abrogates the difference in response between tumors with high and low EF5 uptake pre-treatment, in agreement with traditional radiobiology.
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Affiliation(s)
- Rehan Ali
- Department of Radiation Oncology, Stanford University, Stanford, CA, United States of America
| | - Sandeep Apte
- Department of Radiation Oncology, Stanford University, Stanford, CA, United States of America
| | - Marta Vilalta
- Department of Radiation Oncology, Stanford University, Stanford, CA, United States of America
| | - Murugesan Subbarayan
- Department of Radiology, Stanford University, Stanford, CA, United States of America
| | - Zheng Miao
- Department of Radiology, Stanford University, Stanford, CA, United States of America
| | - Frederick T. Chin
- Department of Radiology, Stanford University, Stanford, CA, United States of America
| | - Edward E. Graves
- Department of Radiation Oncology, Stanford University, Stanford, CA, United States of America
- * E-mail:
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Balvert M, van Hoof SJ, Granton PV, Trani D, den Hertog D, Hoffmann AL, Verhaegen F. A framework for inverse planning of beam-on times for 3D small animal radiotherapy using interactive multi-objective optimisation. Phys Med Biol 2015; 60:5681-98. [DOI: 10.1088/0031-9155/60/14/5681] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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24
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Brodin NP, Tang J, Skalina K, Quinn TJ, Basu I, Guha C, Tomé WA. Semi-automatic cone beam CT segmentation of in vivo pre-clinical subcutaneous tumours provides an efficient non-invasive alternative for tumour volume measurements. Br J Radiol 2015; 88:20140776. [PMID: 25823502 DOI: 10.1259/bjr.20140776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the feasibility and accuracy of using cone beam CT (CBCT) scans obtained in radiation studies using the small-animal radiation research platform to perform semi-automatic tumour segmentation of pre-clinical tumour volumes. METHODS Volume measurements were evaluated for different anatomical tumour sites, the flank, thigh and dorsum of the hind foot, for a variety of tumour cell lines. The estimated tumour volumes from CBCT and manual calliper measurements using different volume equations were compared with the "gold standard", measured by weighing the tumours following euthanasia and tumour resection. The correlation between tumour volumes estimated with the different methods, compared with the gold standard, was estimated by the Spearman's rank correlation coefficient, root-mean-square deviation and the coefficient of determination. RESULTS The semi-automatic CBCT volume segmentation performed favourably compared with manual calliper measures for flank tumours ≤2 cm(3) and thigh tumours ≤1 cm(3). For tumours >2 cm(3) or foot tumours, the CBCT method was not able to accurately segment the tumour volumes and manual calliper measures were superior. CONCLUSION We demonstrated that tumour volumes of flank and thigh tumours, obtained as a part of radiation studies using image-guided small-animal irradiators, can be estimated more efficiently and accurately using semi-automatic segmentation from CBCT scans. ADVANCES IN KNOWLEDGE This is the first study evaluating tumour volume assessment of pre-clinical subcutaneous tumours in different anatomical sites using on-board CBCT imaging. We also compared the accuracy of the CBCT method to manual calliper measures, using various volume calculation equations.
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Affiliation(s)
- N P Brodin
- 1 Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY, USA
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