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Xu Z, Luo T, Mao J, McCleary C, Yuan E, Lin W. Monte Carlo Simulation-Guided Design of a Thorium-Based Metal-Organic Framework for Efficient Radiotherapy-Radiodynamic Therapy. Angew Chem Int Ed Engl 2022; 61:e202208685. [PMID: 36149753 PMCID: PMC9647855 DOI: 10.1002/anie.202208685] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Indexed: 11/09/2022]
Abstract
High-Z metal-based nanoscale metal-organic frameworks (nMOFs) with photosensitizing ligands can enhance radiation damage to tumors via a unique radiotherapy-radiodynamic therapy (RT-RDT) process. Here we report Monte Carlo (MC) simulation-guided design of a Th-based nMOF built from Th6 -oxo secondary building units and 5,15-di(p-benzoato)porphyrin (DBP) ligands, Th-DBP, for enhanced RT-RDT. MC simulations revealed that the Th-lattice outperformed the Hf-lattice in radiation dose enhancement owing to its higher mass attenuation coefficient. Upon X-ray or γ-ray radiation, Th-DBP enhanced energy deposition, generated more reactive oxygen species, and induced significantly higher cytotoxicity to cancer cells over the previously reported Hf-DBP nMOF. With low-dose X-ray irradiation, Th-DBP suppressed tumor growth by 88 % in a colon cancer and 97 % in a pancreatic cancer mouse model.
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Affiliation(s)
- Ziwan Xu
- Department of Chemistry, The University of Chicago, Chicago, IL 60637 (USA)
| | - Taokun Luo
- Department of Chemistry, The University of Chicago, Chicago, IL 60637 (USA)
| | - Jianming Mao
- Department of Chemistry, The University of Chicago, Chicago, IL 60637 (USA)
| | - Caroline McCleary
- Department of Chemistry, The University of Chicago, Chicago, IL 60637 (USA)
| | - Eric Yuan
- Department of Chemistry, The University of Chicago, Chicago, IL 60637 (USA)
| | - Wenbin Lin
- Department of Radiation and Cellular Oncology and Ludwig Center for Metastasis Research, The University of Chicago, Chicago, IL 60637 (USA)
- Department of Chemistry, The University of Chicago, Chicago, IL 60637 (USA)
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2
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Vuori S, Colinet P, Lehtiö JP, Lemiere A, Norrbo I, Granström M, Konu J, Ågren G, Laukkanen P, Petit L, Airaksinen AJ, van Goethem L, Le Bahers T, Lastusaari M. Reusable radiochromic hackmanite with gamma exposure memory. MATERIALS HORIZONS 2022; 9:2773-2784. [PMID: 36069965 DOI: 10.1039/d2mh00593j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Radiochromic films are used as position-sensitive dose meters in e.g. medical physics and radiation processing. The currently available films like those based on lithium-10,12-pentacosdiynoate or leucomalachite green are either toxic or non-reusable, or both. There is thus a great need for a sustainable solution for radiochromic detection. In the present work, we present a suitable candidate: hackmanite with the general formula Na8Al6Si6O24(Cl,S)2. This material is known as a natural intelligent material capable of changing color when exposed to ultraviolet radiation or X-rays. Here, we show for the first time that hackmanites are also radiochromic when exposed to alpha particles, beta particles (positrons) or gamma radiation. Combining experimental and computational data we elucidate the mechanism of gamma-induced radiochromism in hackmanites. We show that hackmanites can be used for gamma dose mapping in high dose applications as well as a memory material that has the one-of-a-kind ability to remember earlier gamma exposure. In addition to satisfying the requirements of sustainability, hackmanites are non-toxic and the films made of hackmanite are reusable thus showing great potential to replace the currently available radiochromic films.
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Affiliation(s)
- Sami Vuori
- Department of Chemistry, University of Turku, FI-20014 Turku, Finland.
- University of Turku Graduate School (UTUGS), Doctoral Programme in Physical and Chemical Sciences (PCS), FI-20014 Turku, Finland
| | - Pauline Colinet
- Laboratoire de Chimie, University of Lyon, ENS de Lyon, CNRS, Université Lyon 1, UMR 5182, Lyon, France.
| | - Juha-Pekka Lehtiö
- University of Turku Graduate School (UTUGS), Doctoral Programme in Physical and Chemical Sciences (PCS), FI-20014 Turku, Finland
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
| | - Arnaud Lemiere
- Photonics Laboratory, Tampere University, FI-33720 Tampere, Finland
| | - Isabella Norrbo
- Department of Chemistry, University of Turku, FI-20014 Turku, Finland.
| | | | - Jari Konu
- Department of Chemistry, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Göran Ågren
- FOI, Swedish Defence Research Agency, SE-90182 Umeå, Sweden
| | - Pekka Laukkanen
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
| | - Laeticia Petit
- Photonics Laboratory, Tampere University, FI-33720 Tampere, Finland
| | - Anu J Airaksinen
- Department of Chemistry, Turku PET Centre, University of Turku, FI-20521 Turku, Finland
| | - Ludo van Goethem
- Mineralogical Society of Antwerp, Boterlaarbaan 225, 2100 Deurne, Belgium
| | - Tangui Le Bahers
- Laboratoire de Chimie, University of Lyon, ENS de Lyon, CNRS, Université Lyon 1, UMR 5182, Lyon, France.
| | - Mika Lastusaari
- Department of Chemistry, University of Turku, FI-20014 Turku, Finland.
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Cho Y, Mirzapour-Kouhdasht A, Yun H, Park JH, Min HJ, Lee CW. Development of Cobalt-Binding Peptide Chelate from Human Serum Albumin: Cobalt-Binding Properties and Stability. Int J Mol Sci 2022; 23:719. [PMID: 35054904 PMCID: PMC8775498 DOI: 10.3390/ijms23020719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 11/16/2022] Open
Abstract
Radioactive isotopes are used as drugs or contrast agents in the medical field after being conjugated with chelates such as DOTA, NOTA, DTPA, TETA, CyDTA, TRITA, and DPDP. The N-terminal sequence of human serum albumin (HSA) is known as a metal binding site, such as for Co2+, Cu2+, and Ni2+. For this study, we designed and synthesized wAlb12 peptide from the N-terminal region of HSA, which can bind to cobalt, to develop a peptide-based chelate. The wAlb12 with a random coil structure tightly binds to the Co(II) ion. Moreover, the binding property of wAlb12 toward Co(II) was confirmed using various spectroscopic experiments. To identify the binding site of wAlb12, the analogs were synthesized by alanine scanning mutagenesis. Among them, H3A and Ac-wAlb12 did not bind to Co(II). The analysis of the binding regions confirmed that the His3 and α-amino group of the N-terminal region are important for Co(II) binding. The wAlb12 bound to Co(II) with Kd of 75 μM determined by isothermal titration calorimetry when analyzed by a single-site binding model. For the use of wAlb12 as a chelate in humans, its cytotoxicity and stability were investigated. Trypsin stability showed that the wAlb12 - Co(II) complex was more stable than wAlb12 alone. Furthermore, the cell viability analysis showed wAlb12 and wAlb12 + Co(II) to be non-toxic to the Raw 264.7 and HEK 293T cell lines. Therefore, a hot radioactive isotope such as cobalt-57 will have the same effect as a stable isotope cobalt. Accordingly, we expect wAlb12 to be used as a peptide chelate that binds with radioactive isotopes.
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Affiliation(s)
- Yeonje Cho
- Department of Chemistry, Chonnam National University, Gwangju 61186, Korea; (Y.C.); (A.M.-K.); (H.Y.)
| | - Armin Mirzapour-Kouhdasht
- Department of Chemistry, Chonnam National University, Gwangju 61186, Korea; (Y.C.); (A.M.-K.); (H.Y.)
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Dublin, Ireland
| | - Hyosuk Yun
- Department of Chemistry, Chonnam National University, Gwangju 61186, Korea; (Y.C.); (A.M.-K.); (H.Y.)
| | - Jeong Hoon Park
- Accelerator Radioisotope Development Laboratory, Korea Atomic Energy Research Institute, Jeongeup-si 56212, Jeollabuk-do, Korea;
| | - Hye Jung Min
- Department of Cosmetic Science, Kwangju Women’s University, Gwangju 62396, Korea;
| | - Chul Won Lee
- Department of Chemistry, Chonnam National University, Gwangju 61186, Korea; (Y.C.); (A.M.-K.); (H.Y.)
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Hernández-Romero D, Rosete-Luna S, López-Monteon A, Chávez-Piña A, Pérez-Hernández N, Marroquín-Flores J, Cruz-Navarro A, Pesado-Gómez G, Morales-Morales D, Colorado-Peralta R. First-row transition metal compounds containing benzimidazole ligands: An overview of their anticancer and antitumor activity. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213930] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Niroomand‐Rad A, Chiu‐Tsao S, Grams MP, Lewis DF, Soares CG, Van Battum LJ, Das IJ, Trichter S, Kissick MW, Massillon‐JL G, Alvarez PE, Chan MF. Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG‐55. Med Phys 2020; 47:5986-6025. [DOI: 10.1002/mp.14497] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Indra J. Das
- Radiation Oncology Northwestern University Memorial Hospital Chicago IL USA
| | - Samuel Trichter
- New York‐Presbyterian HospitalWeill Cornell Medical Center New York NY USA
| | | | - Guerda Massillon‐JL
- Instituto de Fisica Universidad Nacional Autonoma de Mexico Mexico City Mexico
| | - Paola E. Alvarez
- Imaging and Radiation Oncology Core MD Anderson Cancer Center Houston TX USA
| | - Maria F. Chan
- Memorial Sloan Kettering Cancer Center Basking Ridge NJ USA
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Rani AR, Ayyangar K, Reddy AR, Kumar AA, Reddy PRY. Efficacy of MLC based cobalt-60 plans: A DVH comparison and analysis with 6 MV plans. Med Dosim 2020; 46:80-85. [PMID: 32988718 DOI: 10.1016/j.meddos.2020.09.002] [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: 05/08/2020] [Revised: 08/10/2020] [Accepted: 09/01/2020] [Indexed: 10/23/2022]
Abstract
The purpose of this study was to compare 3D treatment plans implemented using 6 MV Linac with a retrofitted multileaf collimator (MLC) based cobalt-60 plans. In this retrospective study, DVH analysis was used to compare homogeneity of dose within the target and the dose received by critical organs. A prototype MLC designed and developed as a retrofit to current cobalt-60 teletherapy machines with a dedicated 3D treatment planning system was used. Cases representing 5 tumor sites like head & neck, glottis, lung, gall bladder, stomach were taken for the study, which were planned using Eclipse treatment planning system and treated with 6 MV photon beams. The plans were re-planned using the retrofit cobalt-60 MLC with same beam arrangement and dose prescription in Radiation Oncology planning system (ROPS). For each case, DVH data was evaluated for both types of beam energies. Conformity index (CI) and homogeneity index (HI) for target were calculated and compared. The conformal plans created using cobalt MLC for five sites were found to be similar to those planned using 6 MV photon beams. CI values close to unity reflected dose uniformity in the target volume while HI evaluated the hotspots in the target volume. It was concluded that plans created using retrofit prototype MLC developed for cobalt-60 teletherapy machines can provide dose distributions comparable to 6 MV photon beams. The prototype MLC developed can provide a promising treatment option for existing telecobalt machines in implementing conformal therapy in developing countries.
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Affiliation(s)
- Akula Roopa Rani
- Department of Physics, Osmania University, Hyderabad, India; Department of Radiation Oncology, MNJ Institute of Oncology & Regional Cancer Center, Hyderabad, India; Department of Radiation Oncology, International Cancer Centre, MGMMT, Bhimavaram, India.
| | - Komanduri Ayyangar
- Department of Radiation Oncology, International Cancer Centre, MGMMT, Bhimavaram, India
| | - A R Reddy
- Department of Radiation Oncology, International Cancer Centre, MGMMT, Bhimavaram, India
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Yantasee W, Fryxell GE, Pattamakomsan K, Sangvanich T, Wiacek RJ, Busche B, Addleman RS, Timchalk C, Ngamcherdtrakul W, Siriwon N. Selective capture of radionuclides (U, Pu, Th, Am and Co) using functional nanoporous sorbents. JOURNAL OF HAZARDOUS MATERIALS 2019; 366:677-683. [PMID: 30580142 PMCID: PMC6927554 DOI: 10.1016/j.jhazmat.2018.12.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/29/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
This work evaluated sorbent materials created from nanoporous silica self-assembled with monolayer (SAMMS) of hydroxypyridinone derivatives (1,2-HOPO, 3,2-HOPO, 3,4-HOPO), acetamide phosphonate (Ac-Phos), glycine derivatives (IDAA, DE4A, ED3A), and thiol (SH) for capturing of actinides and transition metal cobalt. In filtered seawater doped with competing metals (Cr, Mn, Fe, Co, Cu, Zn, Se, Mo) at levels encountered in environmental or physiological samples, 3,4-HOPO-SAMMS was best at capturing uranium (U(VI)) from pH 2-8, Ac-Phos and 1,2-HOPO-SAMMS sorbents were best at pH < 2. 3,4-HOPO-SAMMS effectively captured thorium (Th(IV)) and plutonium (239Pu(IV)) from pH 2-8, and americium (241Am(III)) from pH 5-8. Capturing cobalt (Co(II)) from filtered river water doped with competing metals (Cu, As, Ag, Cd, Hg, Tl, and Pb) was most effective from pH 5-8 with binding affinity ranged from IDAA > DE4A > ED3A > Ac-Phos > SH on SAMMS. Iminodiacetic acid (IDAA)-SAMMS was also outstanding at capturing Co(II) in ground and seawater. Within 5 min, over 99% of U(VI) and Co(II) in seawater was captured by 3,4-HOPO-SAMMS and IDAA-SAMMS, respectively. These nanoporous materials outperformed the commercially available cation sorbents in binding affinity and adsorption rate. They have great potential for water treatment and recovery of actinides and cobalt from complex matrices.
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Affiliation(s)
- Wassana Yantasee
- Department of Biomedical Engineering, Oregon Health and Science University (OHSU) School of Medicine, Portland, OR, USA.
| | - Glen E Fryxell
- Pacific Northwest National Laboratory (PNNL), Richland, WA, USA
| | | | - Thanapon Sangvanich
- Department of Biomedical Engineering, Oregon Health and Science University (OHSU) School of Medicine, Portland, OR, USA
| | - Robert J Wiacek
- Pacific Northwest National Laboratory (PNNL), Richland, WA, USA
| | - Brad Busche
- Pacific Northwest National Laboratory (PNNL), Richland, WA, USA
| | | | | | - Worapol Ngamcherdtrakul
- Department of Biomedical Engineering, Oregon Health and Science University (OHSU) School of Medicine, Portland, OR, USA
| | - Natnaree Siriwon
- Department of Biomedical Engineering, Oregon Health and Science University (OHSU) School of Medicine, Portland, OR, USA
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8
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Oeck S, Szymonowicz K, Wiel G, Krysztofiak A, Lambert J, Koska B, Iliakis G, Timmermann B, Jendrossek V. Relating Linear Energy Transfer to the Formation and Resolution of DNA Repair Foci After Irradiation with Equal Doses of X-ray Photons, Plateau, or Bragg-Peak Protons. Int J Mol Sci 2018; 19:ijms19123779. [PMID: 30486506 PMCID: PMC6320817 DOI: 10.3390/ijms19123779] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 11/24/2018] [Accepted: 11/26/2018] [Indexed: 12/27/2022] Open
Abstract
Proton beam therapy is increasingly applied for the treatment of human cancer, as it promises to reduce normal tissue damage. However, little is known about the relationship between linear energy transfer (LET), the type of DNA damage, and cellular repair mechanisms, particularly for cells irradiated with protons. We irradiated cultured cells delivering equal doses of X-ray photons, Bragg-peak protons, or plateau protons and used this set-up to quantitate initial DNA damage (mainly DNA double strand breaks (DSBs)), and to analyze kinetics of repair by detecting γH2A.X or 53BP1 using immunofluorescence. The results obtained validate the reliability of our set-up in delivering equal radiation doses under all conditions employed. Although the initial numbers of γH2A.X and 53BP1 foci scored were similar under the different irradiation conditions, it was notable that the maximum foci level was reached at 60 min after irradiation with Bragg-peak protons, as compared to 30 min for plateau protons and photons. Interestingly, Bragg-peak protons induced larger and irregularly shaped γH2A.X and 53BP1 foci. Additionally, the resolution of these foci was delayed. These results suggest that Bragg-peak protons induce DNA damage of increased complexity which is difficult to process by the cellular repair apparatus.
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Affiliation(s)
- Sebastian Oeck
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Virchowstrasse 173, 45122 Essen, Germany.
- Department of Therapeutic Radiology, Yale University School of Medicine, 15 York Street, New Haven, CT 06520, USA.
| | - Klaudia Szymonowicz
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Virchowstrasse 173, 45122 Essen, Germany.
| | - Gesa Wiel
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Virchowstrasse 173, 45122 Essen, Germany.
| | - Adam Krysztofiak
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Virchowstrasse 173, 45122 Essen, Germany.
| | - Jamil Lambert
- West German Proton Therapy Centre Essen, University Hospital Essen, Am Muehlenbach 1, 45147 Essen, Germany.
| | - Benjamin Koska
- West German Proton Therapy Centre Essen, University Hospital Essen, Am Muehlenbach 1, 45147 Essen, Germany.
| | - George Iliakis
- Institute of Medical Radiation Biology; University of Duisburg-Essen; Medical School; Hufelandstr. 55, 45122 Essen, Germany.
| | - Beate Timmermann
- West German Proton Therapy Centre Essen, University Hospital Essen, Am Muehlenbach 1, 45147 Essen, Germany.
| | - Verena Jendrossek
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Medical School, Virchowstrasse 173, 45122 Essen, Germany.
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Abstract
The radioisotope cobalt-60 (Co-60) is important for commercial, medical, and agricultural applications. Its widespread use has meant that Co-60 can be found in less secured facilities, leading to the fear that unauthorized persons could obtain and use it to produce a "dirty bomb". This potential security concern has led to government calls for phasing-out Co-60 and other radiation sources, despite ongoing safety and security regulations for handling, transport and use of radioactive sealed sources. This paper explores potential implications of phasing out radioisotopic technologies, including unintended safety and cost consequences for healthcare and food in the US and globally. The use of Co-60 for healthcare and agricultural applications is well-documented. Co-60 is used to sterilize single-use medical devices, tissue allografts, and a range of consumer products. Co-60 is used in Gamma Knife treatment of brain tumors in over 70,000 patients annually. Co-60 is also used to preserve food and kill insects and pathogens that cause food-borne illness. Co-60 is effective, reliable, and predictable. Limitations of alternative sterilization technologies include complex equipment, toxicities, incompatibilities with plastic, and physical hazards. Alternative ionizing radiation sources for wide-reaching applications, including e-beam and x-ray radiation, have advantages and drawbacks related to commercial scale capacity, penetrability, complexity and reliability. Identifying acceptable alternatives would require time, costs and lengthy regulatory review. FDA testing requirements and other hurdles would delay replacement of existing technologies and slow medical innovation, even delaying access to life-saving therapies. A phase-out would raise manufacturing costs, and reduce supply-chain efficiencies, potentially increasing consumer prices, and reducing supply. These consequences are poorly understood and merit additional research. Given Co-60's importance across medical and non-medical fields, restrictions on Co-60 warrant careful consideration and evaluation before adoption.
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Heunis M, Lombe DC, McCaul M. Retrospective analysis of radiotherapy outcomes in breast cancer radiotherapy at a single institution. SOUTHERN AFRICAN JOURNAL OF GYNAECOLOGICAL ONCOLOGY 2018. [DOI: 10.1080/20742835.2018.1429521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Affiliation(s)
- M Heunis
- Radiation Oncology, Tygerberg Hospital/Stellenbosch University, Parow, South Africa
| | - DC Lombe
- Radiation Oncology, Tygerberg Hospital/Stellenbosch University, Parow, South Africa
| | - M McCaul
- Biostatistics Unit, Division of Epidemiology and Biostatistics, Department of Global Health, Stellenbosch University, Stellenbosch, South Africa
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Sri Krishna G, Akula R. DVH Analysis of Cobalt-60 treatment plans incorporating a recently developed MLC. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2016. [DOI: 10.14319/ijcto.43.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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12
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Walters BRB. Increasing efficiency of BEAMnrc-simulated Co-60 beams using directional source biasing. Med Phys 2016; 42:5817-27. [PMID: 26429256 DOI: 10.1118/1.4930060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE This study describes the implementation of a directional source biasing (DSB) scheme for efficiently simulating Cobalt-60 treatment heads using the BEAMnrc Monte Carlo code. Previous simulation of Co-60 beams with BEAMnrc was impractical because of the time required to track photons not directed into the treatment field and to simulate secondary charged particles. METHODS In DSB, efficiency is increased by splitting each photon emitted by the Co-60 source a user-defined number of times. Only those split primary photons directed into a user-defined splitting field (encompassing the treatment field) are sampled, yielding many low-weight photons directed into the field. Efficiency can be further increased by taking advantage of radial symmetry at the top of the treatment head to reduce the number of split primary photons tracked in this portion. There is also an option to generate contaminant electrons in DSB. RESULTS The DSB scheme in BEAMnrc increases the photon fluence calculation efficiency in a 10 × 10 cm(2) Co-60 beam by a factor of 1800 with a concurrent increase in contaminant electron fluence calculation efficiency by a factor of 1200. Implementation of DSB in beampp, a C++ code for accelerator simulations based on EGSnrc and the C++ class library, egspp, increases photon fluence efficiency by a factor of 2800 and contaminant electron fluence efficiency by a factor of 1600. Optimum splitting numbers are in the range of 20,000-40,000. For dose calculations in a water phantom (0.5 × 0.5 × 0.5 cm(3) voxels) this translates into a factor of ∼400 increase in dose calculation efficiency (all doses > 0.5 × Dmax). An example calculation of the ratio of dose to water to dose to chamber (the basis of the beam quality correction factor) to within 0.2% in a realistic chamber using a full simulation of a Co-60 treatment head as a source indicates the practicality of Co-60 simulations with DSB. CONCLUSIONS The efficiency improvement resulting from DSB makes Monte Carlo commissioning of Co-60 beams and calculation of beam quality correction factors feasible.
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Affiliation(s)
- B R B Walters
- Ionizing Radiation Standards, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
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13
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A treatment planning comparison between modulated tri-cobalt-60 teletherapy and linear accelerator-based stereotactic body radiotherapy for central early-stage non-small cell lung cancer. Med Dosim 2016; 41:87-91. [PMID: 26755076 DOI: 10.1016/j.meddos.2015.09.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 07/25/2015] [Accepted: 09/11/2015] [Indexed: 01/09/2023]
Abstract
We evaluated the feasibility of planning stereotactic body radiotherapy (SBRT) for large central early-stage non-small cell lung cancer with a tri-cobalt-60 (tri-(60)Co) system equipped with real-time magnetic resonance imaging (MRI) guidance, as compared to linear accelerator (LINAC)-based SBRT. In all, 20 patients with large central early-stage non-small cell lung cancer who were treated between 2010 and 2015 with LINAC-based SBRT were replanned using a tri-(60)Co system for a prescription dose of 50Gy in 4 fractions. Doses to organs at risk were evaluated based on established MD Anderson constraints for central lung SBRT. R100 values were calculated as the total tissue volume receiving 100% of the dose (V100) divided by the planning target volume and compared to assess dose conformity. Dosimetric comparisons between LINAC-based and tri-(60)Co SBRT plans were performed using Student׳s t-test and Wilcoxon Ranks test. Blinded reviews by radiation oncologists were performed to assess the suitability of both plans for clinical delivery. The mean planning target volume was 48.3cc (range: 12.1 to 139.4cc). Of the tri-(60)Co SBRT plans, a mean 97.4% of dosimetric parameters per patient met MD Anderson dose constraints, whereas a mean 98.8% of dosimetric parameters per patient were met with LINAC-based SBRT planning (p = 0.056). R100 values were similar between both plans (1.20 vs 1.21, p = 0.79). Upon blinded review by 4 radiation oncologists, an average of 90% of the tri-(60)Co SBRT plans were considered acceptable for clinical delivery compared with 100% of the corresponding LINAC-based SBRT plans (p = 0.17). SBRT planning using the tri-(60)Co system with built-in MRI is feasible and achieves clinically acceptable plans for most central lung patients, with similar target dose conformity and organ at risk dosimetry. The added benefit of real-time MRI-guided therapy may further optimize tumor targeting while improving normal tissue sparing, which warrants further investigation in a prospective feasibility clinical trial.
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Sullivan R, Badwe RA, Rath GK, Pramesh CS, Shanta V, Digumarti R, D'Cruz A, Sharma SC, Viswanath L, Shet A, Vijayakumar M, Lewison G, Chandy M, Kulkarni P, Bardia MR, Kumar S, Sarin R, Sebastian P, Dhillon PK, Rajaraman P, Trimble EL, Aggarwal A, Vijaykumar DK, Purushotham AD. Cancer research in India: national priorities, global results. Lancet Oncol 2014; 15:e213-22. [DOI: 10.1016/s1470-2045(14)70109-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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15
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Marsh MB, Peters C, Rawluk N, Schreiner LJ. Investigation of photon shielding property changes in curing high density concrete. HEALTH PHYSICS 2013; 105:318-325. [PMID: 23982607 DOI: 10.1097/hp.0b013e31829651d3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
High density concrete is usually used for radiation shielding around radiotherapy treatment rooms. Because the concrete is specified differently at the design, construction, and verification stages, the relationship between the intended performance and the actual performance of the shielding material might not be entirely clear. In this study, cylindrical samples of high density shielding concrete were taken as each section of a new radiotherapy bunker was poured. The shielding performance of each sample [measured by beam attenuation and tenth-value layers (TVL)] was evaluated for 15 MV and 6 MV x-ray beams and for the 1.25 MeV monoenergetic gamma beam from a Co source. Transmission curves to 3 TVL were mapped for a representative sample. The samples were also imaged and analyzed using Co Cone Beam Computed Tomography (CoCBCT). Results indicate no significant change in the TVL of high density concrete samples as they cure. The minor fluctuations in shielding properties observed are explained by the heterogeneous structure of the samples as indicated in the CoCBCT images.
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Affiliation(s)
- Matthew B Marsh
- Department of Physics, Queen's University, Kingston, Ontario, Canada
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Dhanesar S, Darko J, Joshi CP, Kerr A, John Schreiner L. Cobalt-60 tomotherapy: Clinical treatment planning and phantom dose delivery studies. Med Phys 2013; 40:081710. [DOI: 10.1118/1.4812417] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Sahani G, Dutt Sharma S, Dash Sharma PK, Sharma DN, Hussain SA. Monte Carlo simulation based study of a proposed multileaf collimator for a telecobalt machine. Med Phys 2013; 40:021705. [DOI: 10.1118/1.4773308] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Dhanesar S, Darko J, Schreiner LJ. Aperture superposition dose model versus pencil beam superposition dose model for a finite size Cobalt-60 source for tomotherapy deliveries. Med Phys 2011; 39:206-13. [DOI: 10.1118/1.3665706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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