1
|
Carrasco-Hernandez J, Ramos-Méndez J, Padilla-Rodal E, Avila-Rodriguez MA. Cellular lethal damage of 64Cu incorporated in mammalian genome evaluated with Monte Carlo methods. Front Med (Lausanne) 2023; 10:1253746. [PMID: 37841004 PMCID: PMC10575761 DOI: 10.3389/fmed.2023.1253746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/13/2023] [Indexed: 10/17/2023] Open
Abstract
Purpose Targeted Radionuclide Therapy (TRT) with Auger Emitters (AE) is a technique that allows targeting specific sites on tumor cells using radionuclides. The toxicity of AE is critically dependent on its proximity to the DNA. The aim of this study is to quantify the DNA damage and radiotherapeutic potential of the promising AE radionuclide copper-64 (64Cu) incorporated into the DNA of mammalian cells using Monte Carlo track-structure simulations. Methods A mammalian cell nucleus model with a diameter of 9.3 μm available in TOPAS-nBio was used. The cellular nucleus consisted of double-helix DNA geometrical model of 2.3 nm diameter surrounded by a hydration shell with a thickness of 0.16 nm, organized in 46 chromosomes giving a total of 6.08 giga base-pairs (DNA density of 14.4 Mbp/μm3). The cellular nucleus was irradiated with monoenergetic electrons and radiation emissions from several radionuclides including 111In, 125I, 123I, and 99mTc in addition to 64Cu. For monoenergetic electrons, isotropic point sources randomly distributed within the nucleus were modeled. The radionuclides were incorporated in randomly chosen DNA base pairs at two positions near to the central axis of the double-helix DNA model at (1) 0.25 nm off the central axis and (2) at the periphery of the DNA (1.15 nm off the central axis). For all the radionuclides except for 99mTc, the complete physical decay process was explicitly simulated. For 99mTc only total electron spectrum from published data was used. The DNA Double Strand Breaks (DSB) yield per decay from direct and indirect actions were quantified. Results obtained for monoenergetic electrons and radionuclides 111In, 125I, 123I, and 99mTc were compared with measured and calculated data from the literature for verification purposes. The DSB yields per decay incorporated in DNA for 64Cu are first reported in this work. The therapeutic effect of 64Cu (activity that led 37% cell survival after two cell divisions) was determined in terms of the number of atoms incorporated into the nucleus that would lead to the same DSBs that 100 decays of 125I. Simulations were run until a 2% statistical uncertainty (1 standard deviation) was achieved. Results The behavior of DSBs as a function of the energy for monoenergetic electrons was consistent with published data, the DSBs increased with the energy until it reached a maximum value near 500 eV followed by a continuous decrement. For 64Cu, when incorporated in the genome at evaluated positions (1) and (2), the DSB were 0.171 ± 0.003 and 0.190 ± 0.003 DSB/decay, respectively. The number of initial atoms incorporated into the genome (per cell) for 64Cu that would cause a therapeutic effect was estimated as 3,107 ± 28, that corresponds to an initial activity of 47.1 ± 0.4 × 10-3 Bq. Conclusion Our results showed that TRT with 64Cu has comparable therapeutic effects in cells as that of TRT with radionuclides currently used in clinical practice.
Collapse
Affiliation(s)
- Jhonatan Carrasco-Hernandez
- Departamento de Estructura de la Materia, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - José Ramos-Méndez
- Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA, United States
| | - Elizabeth Padilla-Rodal
- Departamento de Estructura de la Materia, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Miguel A. Avila-Rodriguez
- Unidad Radiofarmacia-Ciclotrón, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| |
Collapse
|
2
|
Borbinha J, Ferreira P, Costa D, Vaz P, Di Maria S. Targeted radionuclide therapy directed to the tumor phenotypes: A dosimetric approach using MC simulations. Appl Radiat Isot 2023; 192:110569. [PMID: 36436229 DOI: 10.1016/j.apradiso.2022.110569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/07/2022] [Accepted: 11/16/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND In Targeted Radionuclide Therapy (TRT), the continuous technological effort in imaging tumor phenotypes (i.e. sub-volumes with different phenotypic characteristics) and in precise radiopharmaceutical tumor-targeting, is allowing for a better dosimetric optimization at the tumor phenotype level. The aim of this study was to evaluate the dosimetric efficiency (considering strategic absorbed dose delivery to the phenotypes) of personalized TRT directed to the tumor phenotypes. METHODS The dosimetric assessment was performed using a four-phenotype realistic tumor model implemented within the ICRP reference voxel phantom and simulations using the state-of-the-art Monte Carlo program PENELOPE. The dose assessment was performed for five radionuclides commonly used in therapy and/or diagnostic procedures: 125I, 99mTc, 177Lu, 161Tb and 67Ga. Two irradiation scenarios were considered: (i) the Whole Tumor Treatment Planning Scenario (WTTPS), i.e. the four phenotypes irradiated with the same radionuclide; (ii) the Phenotype Treatment Planning Scenario (PTPS), i.e. each phenotype irradiated by a single radionuclide. The optimal radionuclide configurations were studied considering the maximization of the absorbed dose delivered to the tumor and the minimization of dose to healthy tissues. RESULTS In WTTPS, 125I outperforms the other radionuclides in terms of the ratio of the maximum absorbed dose delivered to the tumor and the minimum absorbed dose delivered to healthy tissues. In the PTPS, the use of 161Tb in combination with the other radionuclides maximizes the absorbed dose in the tumor tissues while simultaneously minimizing dose to healthy tissue, compared to the WTTPS. In agreement with recent pre-clinical studies, our computational results confirm and indicate the beneficial additive dosimetric effects of Auger and conversion electrons of 161Tb with respect to 177Lu, when considering the same cumulated activity for both. Interestingly, in considering a realistic tumor model, the better dosimetric performances of 161Tb were confirmed also for tumor volumes ranging from 1.98 cm3 to 33.32 cm3. CONCLUSIONS Dose assessment in realistic non-homogeneous tumor models could provide more insights with respect to consider only homogenous water-spheres tumor models and should be taken into account in dosimetry-based TRT planning studies.
Collapse
Affiliation(s)
- Jorge Borbinha
- Centro de Ciências e Tecnologias Nucleares - Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7, 2695-066, Bobadela, Portugal.
| | - Paulo Ferreira
- Champalimaud Centre for the Unknown, Fundação Champalimaud, Avenida Brasília, 1400-038, Lisboa, Portugal.
| | - Durval Costa
- Champalimaud Centre for the Unknown, Fundação Champalimaud, Avenida Brasília, 1400-038, Lisboa, Portugal.
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares - Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7, 2695-066, Bobadela, Portugal.
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares - Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7, 2695-066, Bobadela, Portugal.
| |
Collapse
|
3
|
Cai Z, Al-Saden N, Georgiou CJ, Reilly RM. Cellular dosimetry of 197Hg, 197mHg and 111In: comparison of dose deposition and identification of the cell and nuclear membrane as important targets. Int J Radiat Biol 2023; 99:53-63. [PMID: 33179984 DOI: 10.1080/09553002.2020.1849850] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE To examine the reliability to model cellular S-values for the Auger electron (AE) emitters, 111In, 197Hg and 197mHg with MCNP6 and their relative dose deposition in subcellular targets. METHODS A model cell was defined as four concentric spheres consisting of the nucleus (N), cytoplasm (Cy), cell and nuclear membranes (CM, NM) in which radionuclides distributed homogeneously. The transport of AE, conversion electrons and photons were simulated by MCNP6 to calculate cellular S values (SN←CM, SN←Cy, SN←NM, SN←N, SCM←CM, SNM←NM). SN←CM, SN←Cy and SN←N were also calculated with MIRDcell. RESULTS MIRDcell and MCNP6-calculated SN←N were in excellent agreement, but a slight discrepancy on SN←Cy and SN←CM was observed. The ratios of SCM←CM or SNM←NM vs. SN←N were 9.7-51.0 or 10.5-37.4, 7.9-41.8 or 8.4-31.8 and 7.2-36.9 or 8.0-28.1 for 111In, 197Hg, 197mHg, respectively. The mean S(197Hg)/S(111In) and S(197mHg)/S(111In) were 2.5 ± 0.5 and 2.5 ± 0.6, respectively. CONCLUSIONS Cellular S-values were reliably calculated with MCNP6. 197Hg and 197mHg deposit two-fold more doses than 111In at the subcellular scale. All AE emitters deposit a higher self-dose in the CM and NM than in the N, which warrants studies on the effects of targeting the CM and NM by AE emitters.
Collapse
Affiliation(s)
- Zhongli Cai
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Canada
| | - Noor Al-Saden
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Canada
| | | | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Canada.,Department of Medical Imaging, University of Toronto, Toronto, Canada.,Princess Margaret Cancer Centre and Joint Department of Medical Imaging, University Health Network, Toronto, Canada
| |
Collapse
|
4
|
Spoormans K, Crabbé M, Struelens L, De Saint-Hubert M, Koole M. A Review on Tumor Control Probability (TCP) and Preclinical Dosimetry in Targeted Radionuclide Therapy (TRT). Pharmaceutics 2022; 14:2007. [PMID: 36297446 PMCID: PMC9608466 DOI: 10.3390/pharmaceutics14102007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 12/05/2022] Open
Abstract
Targeted radionuclide therapy (TRT) uses radiopharmaceuticals to specifically irradiate tumor cells while sparing healthy tissue. Response to this treatment highly depends on the absorbed dose. Tumor control probability (TCP) models aim to predict the tumor response based on the absorbed dose by taking into account the different characteristics of TRT. For instance, TRT employs radiation with a high linear energy transfer (LET), which results in an increased effectiveness. Furthermore, a heterogeneous radiopharmaceutical distribution could result in a heterogeneous dose distribution at a tissue, cellular as well as subcellular level, which will generally reduce the tumor response. Finally, the dose rate in TRT is protracted, relatively low, and variable over time. This allows cells to repair more DNA damage, which may reduce the effectiveness of TRT. Within this review, an overview is given on how these characteristics can be included in TCP models, while some experimental findings are also discussed. Many parameters in TCP models are preclinically determined and TCP models also play a role in the preclinical stage of radiopharmaceutical development; however, this all depends critically on the calculated absorbed dose. Accordingly, an overview of the existing preclinical dosimetry methods is given, together with their limitation and applications. It can be concluded that although the theoretical extension of TCP models from external beam radiotherapy towards TRT has been established quite well, the experimental confirmation is lacking. Thus, requiring additional comprehensive studies at the sub-cellular, cellular, and organ level, which should be provided with accurate preclinical dosimetry.
Collapse
Affiliation(s)
- Kaat Spoormans
- Research in Dosimetric Applications, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium
- Unit of Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
| | - Melissa Crabbé
- NURA Research Group, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium
| | - Lara Struelens
- Research in Dosimetric Applications, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium
| | - Marijke De Saint-Hubert
- Research in Dosimetric Applications, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium
| | - Michel Koole
- Unit of Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium
| |
Collapse
|
5
|
Salim R, Taherparvar P. Dosimetry assessment of theranostic Auger-emitting radionuclides in a micron-sized multicellular cluster model: A Monte Carlo study using Geant4-DNA simulations. Appl Radiat Isot 2022; 188:110380. [PMID: 35868198 DOI: 10.1016/j.apradiso.2022.110380] [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: 04/04/2022] [Revised: 06/28/2022] [Accepted: 07/07/2022] [Indexed: 11/02/2022]
Abstract
The present work is aimed at improving the multicellular dosimetry of several Auger radionuclides of interest for targeted cancer therapy, including 99mTc, 111In, 123I, 125I, and 201Tl. For this purpose, using the Geant4-DNA Monte Carlo code, a cluster of 13 similar spherical cells with a hexagonal packed arrangement was modeled, and the mean absorbed doses per unit cumulated activity (S-values) were calculated by considering two target←source configurations, cell←cell and nucleus←nucleus. The obtained ratios of cross-dose to self-dose S-value in terms of the distance between the source and target regions were evaluated and also compared to those estimated by the Medical Internal Radiation Dose (MIRD) method. Besides, the contribution of the Coster-Kronig, Auger and internal conversion electrons to the S-values was provided for each radionuclide. According to the results, it can be concluded that in contrast to self-absorption, the cross-absorption due to the Auger-emitters has not a significant role in the total energy deposition within a cell in the cluster.
Collapse
Affiliation(s)
- R Salim
- Department of Physics, Faculty of Science, University of Guilan, Rasht, Iran
| | - P Taherparvar
- Department of Physics, Faculty of Science, University of Guilan, Rasht, Iran.
| |
Collapse
|
6
|
Bzowski P, Borys D, Gorczewski K, Chmura A, Daszewska K, Gorczewska I, Kastelik-Hryniewiecka A, Szydło M, d’Amico A, Sokół M. Efficiency of 124I radioisotope production from natural and enriched tellurium dioxide using 124Te(p,xn) 124I reaction. EJNMMI Phys 2022; 9:41. [PMID: 35666325 PMCID: PMC9170869 DOI: 10.1186/s40658-022-00471-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 05/19/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND 124I Iodine (T[Formula: see text] = 4.18 d) is the only long-life positron emitter radioisotope of iodine that may be used for both imaging and therapy as well as for 131I dosimetry. Its physical characteristics permits taking advantages of the higher Positron Emission Tomography (PET) image quality, whereas the availability of new molecules to be targeted with 124I makes it a novel innovative radiotracer probe for a specific molecular targeting. RESULTS In this study Monte Carlo and SRIM/TRIM modelling was applied to predict the nuclear parameters of the 124I production process in a small medical cyclotron IBA 18/9 Cyclone. The simulation production yields for 124I and the polluting radioisotopes were calculated for the natural and enriched 124TeO2 + Al2O3 solid targets irradiated with 14.8 MeV protons. The proton beam was degraded energetically from 18 MeV with 0.2 mm Havar foil. The 124Te(p,xn)124I reactions were taken into account in the simulations. The optimal thickness of the target material was calculated using the SRIM/TRIM and Geant4 codes. The results of the simulations were compared with the experimental data obtained for the natural TeO2 +Al2O3 target. The dry distillation technique of the 124-iodine was applied. CONCLUSIONS The experimental efficiency for the natural Te target was better than 41% with an average thick target (>0.8 mm) yield of 1.32 MBq/μAh. Joining the Monte Carlo and experimental approaches makes it possible to optimize the methodology for the 124I production from the expensive Te enriched targets.
Collapse
Affiliation(s)
- Paweł Bzowski
- Department of Nuclear Medicine and Endocrine Oncology, PET Diagnostics Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
- Department of Systems Biology and Engineering, Silesian University of Technology, Akademicka 16, 44-100 Gliwice, Poland
- Biotechnology Center, Silesian University of Technology, Krzywoustego 8, 44-100 Gliwice, Poland
| | - Damian Borys
- Department of Nuclear Medicine and Endocrine Oncology, PET Diagnostics Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
- Department of Systems Biology and Engineering, Silesian University of Technology, Akademicka 16, 44-100 Gliwice, Poland
- Biotechnology Center, Silesian University of Technology, Krzywoustego 8, 44-100 Gliwice, Poland
| | - Kamil Gorczewski
- Department of Nuclear Medicine and Endocrine Oncology, PET Diagnostics Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| | - Agnieszka Chmura
- Radiopharmacy and Preclinical PET Imaging Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| | - Kinga Daszewska
- Radiopharmacy and Preclinical PET Imaging Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| | - Izabela Gorczewska
- Department of Nuclear Medicine and Endocrine Oncology, PET Diagnostics Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| | - Anna Kastelik-Hryniewiecka
- Radiopharmacy and Preclinical PET Imaging Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| | - Marcin Szydło
- Radiopharmacy and Preclinical PET Imaging Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| | - Andrea d’Amico
- Department of Nuclear Medicine and Endocrine Oncology, PET Diagnostics Unit, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| | - Maria Sokół
- Department of Medical Physics, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
| |
Collapse
|
7
|
Salim R, Taherparvar P. A Monte Carlo study on the effects of a static uniform magnetic field on micro-scale dosimetry of Auger-emitters using Geant4-DNA. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
8
|
Bastami H, Chiniforoush TA, Heidari S, Sadeghi M. Dose evaluation of auger electrons emitted from the 119Sb in cancer treatment. Appl Radiat Isot 2022; 185:110250. [DOI: 10.1016/j.apradiso.2022.110250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/10/2022] [Accepted: 04/18/2022] [Indexed: 11/16/2022]
|
9
|
The Effect of Hypoxia on Relative Biological Effectiveness and Oxygen Enhancement Ratio for Cells Irradiated with Grenz Rays. Cancers (Basel) 2022; 14:cancers14051262. [PMID: 35267573 PMCID: PMC8909589 DOI: 10.3390/cancers14051262] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/11/2022] [Accepted: 02/25/2022] [Indexed: 12/31/2022] Open
Abstract
Grenz-ray therapy (GT) is commonly used for dermatological radiotherapy and has a higher linear energy transfer, relative biological effectiveness (RBE) and oxygen enhancement ratio (OER). GT is a treatment option for lentigo maligna and lentigo maligna melanoma. This study aims to calculate the RBE for DNA double-strand break (DSB) induction and cell survival under hypoxic conditions for GT. The yield of DSBs induced by GT is calculated at the aerobic and hypoxic conditions, using a Monte Carlo damage simulation (MCDS) software. The RBE value for cell survival is calculated using the repair–misrepair–fixation (RMF) model. The RBE values for cell survival for cells irradiated by 15 kV, 10 kV and 10 kVp and titanium K-shell X-rays (4.55 kV) relative to 60Co γ-rays are 1.0–1.6 at the aerobic conditions and moderate hypoxia (2% O2), respectively, but increase to 1.2, 1.4 and 1.9 and 2.1 in conditions of severe hypoxia (0.1% O2). The OER values for DSB induction relative to 60Co γ-rays are about constant and ~2.4 for GT, but the OER for cell survival is 2.8–2.0 as photon energy decreases from 15 kV to 4.55 kV. The results indicate that GT results in more DSB induction and allows effective tumor control for superficial and hypoxic tumors.
Collapse
|
10
|
Principles and Applications of Auger-Electron Radionuclide Therapy. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00040-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
11
|
Olson AP, Ma L, Feng Y, Najafi Khosroshahi F, Kelley SP, Aluicio-Sarduy E, Barnhart TE, Hennkens HM, Ellison PA, Jurisson SS, Engle JW. A Third Generation Potentially Bifunctional Trithiol Chelate, Its nat,1XXSb(III) Complex, and Selective Chelation of Radioantimony ( 119Sb) from Its Sn Target. Inorg Chem 2021; 60:15223-15232. [PMID: 34606252 DOI: 10.1021/acs.inorgchem.1c01690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The therapeutic potential of the Meitner-Auger- and conversion-electron emitting radionuclide 119Sb remains unexplored because of the difficulty of incorporating it into biologically targeted compounds. To address this challenge, we report the development of 119Sb production from electroplated tin cyclotron targets and its complexation by a novel trithiol chelate. The chelation reaction occurs in harsh solvent conditions even in the presence of large quantities of tin, which are necessary for production on small, low energy (16 MeV) cyclotrons. The 119Sb-trithiol complex has high stability and can be purified by HPLC. The third generation trithiol chelate and the analogous stable natSb-trithiol compound were synthesized and characterized, including by single-crystal X-ray diffraction analyses.
Collapse
Affiliation(s)
- Aeli P Olson
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Li Ma
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Yutian Feng
- Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | | | - Steven P Kelley
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Heather M Hennkens
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States.,University of Missouri Research Reactor (MURR), Columbia, Missouri 65203, United States
| | - Paul A Ellison
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Silvia S Jurisson
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, United States.,Department of Radiology, University of Wisconsin, Madison, Wisconsin 53705, United States
| |
Collapse
|
12
|
Bavelaar BM, Song L, Jackson MR, Able S, Tietz O, Skaripa-Koukelli I, Waghorn PA, Gill MR, Carlisle RC, Tarsounas M, Vallis KA. Oligonucleotide-Functionalized Gold Nanoparticles for Synchronous Telomerase Inhibition, Radiosensitization, and Delivery of Theranostic Radionuclides. Mol Pharm 2021; 18:3820-3831. [PMID: 34449222 PMCID: PMC8493550 DOI: 10.1021/acs.molpharmaceut.1c00442] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/07/2021] [Accepted: 08/11/2021] [Indexed: 12/13/2022]
Abstract
Telomerase represents an attractive target in oncology as it is expressed in cancer but not in normal tissues. The oligonucleotide inhibitors of telomerase represent a promising anticancer strategy, although poor cellular uptake can restrict their efficacy. In this study, gold nanoparticles (AuNPs) were used to enhance oligonucleotide uptake. "match" oligonucleotides complementary to the telomerase RNA template subunit (hTR) and "scramble" (control) oligonucleotides were conjugated to diethylenetriamine pentaacetate (DTPA) for 111In-labeling. AuNPs (15.5 nm) were decorated with a monofunctional layer of oligonucleotides (ON-AuNP) or a multifunctional layer of oligonucleotides, PEG(polethylene glycol)800-SH (to reduce AuNP aggregation) and the cell-penetrating peptide Tat (ON-AuNP-Tat). Match-AuNP enhanced the cellular uptake of radiolabeled oligonucleotides while retaining the ability to inhibit telomerase activity. The addition of Tat to AuNPs increased nuclear localization. 111In-Match-AuNP-Tat induced DNA double-strand breaks and caused a dose-dependent reduction in clonogenic survival of telomerase-positive cells but not telomerase-negative cells. hTR inhibition has been reported to sensitize cancer cells to ionizing radiation, and 111In-Match-AuNP-Tat therefore holds promise as a vector for delivery of radionuclides into cancer cells while simultaneously sensitizing them to the effects of the emitted radiation.
Collapse
Affiliation(s)
- Bas M. Bavelaar
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Lei Song
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Mark R. Jackson
- Institute
of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, University Avenue, Glasgow G12 8QQ, U.K.
| | - Sarah Able
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Ole Tietz
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Irini Skaripa-Koukelli
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Philip A. Waghorn
- Charles
River Laboratories, Elphinstone Research Centre, Elphinstone, Tranent EH33 2NE, U.K.
| | - Martin R. Gill
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Robert C. Carlisle
- Institute
of Biomedical Engineering, Department of Engineering Science, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, U.K.
| | - Madalena Tarsounas
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| | - Katherine A. Vallis
- Oxford
Institute for Radiation Oncology, University
of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K.
| |
Collapse
|
13
|
Moreira HM, Guerra Liberal FD, McMahon SJ, Prise KM. Characterization of a custom-made 241Am alpha-source for radiobiological studies. Appl Radiat Isot 2021; 177:109931. [PMID: 34488046 DOI: 10.1016/j.apradiso.2021.109931] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/15/2021] [Accepted: 08/29/2021] [Indexed: 01/04/2023]
Abstract
A compact in-house alpha particle source has been developed and fully characterized. The irradiation source is a large area, 25 cm2, 5.4 MeV average energy 241Am source, above which a Mylar dish containing a monolayer of target cells can be placed at defined positions. The source uniformity, flux, particle energy and dose rate were determined experimentally. The dose rate to the nucleus at the closest position was 1.57 Gy/min. Furthermore, a 3D printed collimator was tested and found to improve the uniformity of the energy spectra of particles reaching the target. For validation, prostate PC-3 cells were irradiated in our experimental setup with absorbed doses up to 2 Gy and for reference compared with cells irradiated with conventional X-rays with doses up to 8 Gy. The Relative Biological Effectiveness for alpha particles at 10% survival was 3.66± 0.40 agreeing with previously published data. Data presented here show the feasibility of utilising a low-cost alpha-irradiation source for accurate in vitro assays to better understand the radiobiological effects of high LET alpha particles.
Collapse
Affiliation(s)
- Hugo Mr Moreira
- The Patrick G Johnston Centre for Cancer Research, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7AE, United Kingdom
| | - Francisco Dc Guerra Liberal
- The Patrick G Johnston Centre for Cancer Research, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7AE, United Kingdom.
| | - Stephen J McMahon
- The Patrick G Johnston Centre for Cancer Research, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7AE, United Kingdom
| | - Kevin M Prise
- The Patrick G Johnston Centre for Cancer Research, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7AE, United Kingdom
| |
Collapse
|
14
|
Verger E, Cheng J, de Santis V, Iafrate M, Jackson JA, Imberti C, Fruhwirth GO, Blower PJ, Ma MT, Burnham DR, Terry SYA. Validation of the plasmid study to relate DNA damaging effects of radionuclides to those from external beam radiotherapy. Nucl Med Biol 2021; 100-101:36-43. [PMID: 34153932 PMCID: PMC7611685 DOI: 10.1016/j.nucmedbio.2021.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/31/2021] [Accepted: 06/10/2021] [Indexed: 12/29/2022]
Abstract
INTRODUCTION The biological consequences of absorbed radiation doses are ill-defined for radiopharmaceuticals, unlike for external beam radiotherapy (EBRT). A reliable assay that assesses the biological consequences of any radionuclide is much needed. Here, we evaluated the cell-free plasmid DNA assay to determine the relative biological effects of radionuclides such as Auger electron-emitting [67Ga]GaCl3 or [111In]InCl3 compared to EBRT. METHODS Supercoiled pBR322 plasmid DNA (1.25 or 5 ng/μL) was incubated with 0.5 or 1 MBq [67Ga]GaCl3 or [111In]InCl3 for up to 73 h or was exposed to EBRT (137Cs; 5 Gy/min; 0-40 Gy). The induction of relaxed and linear plasmid DNA, representing single and double strand breaks, respectively, was assessed by gel electrophoresis. Chelated forms of 67Ga were also investigated using DOTA and THP. Topological conversion rates for supercoiled-to-relaxed (ksrx) or relaxed-to-linear (krlx) DNA were obtained by fitting a kinetic model. RESULTS DNA damage increased both with EBRT dose and incubation time for [67Ga]GaCl3 and [111In]InCl3. Damage caused by [67Ga]GaCl3 decreased when chelated. [67Ga]GaCl3 proved more damaging than [111In]InCl3; 1.25 ng/μL DNA incubated with 0.5 MBq [67Ga]GaCl3 for 2 h led to a 70% decrease of intact plasmid DNA as opposed to only a 19% decrease for [111In]InCl3. For both EBRT and radionuclides, conversion rates were slower for 5 ng/μL than 1.25 ng/μL plasmid DNA. DNA damage caused by 1 Gy EBRT was the equivalent to damage caused by 0.5 MBq unchelated [67Ga]GaCl3 and [111In]InCl3 after 2.05 ± 0.36 and 9.3 ± 0.77 h of incubation, respectively. CONCLUSIONS This work has highlighted the power of the plasmid DNA assay for a rapid determination of the relative biological effects of radionuclides compared to external beam radiotherapy. It is envisaged this approach will enable the systematic assessment of imaging and therapeutic radionuclides, including Auger electron-emitters, to further inform radiopharmaceutical design and application.
Collapse
Affiliation(s)
- Elise Verger
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Jordan Cheng
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Vittorio de Santis
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Madeleine Iafrate
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Jessica A Jackson
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Cinzia Imberti
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Gilbert O Fruhwirth
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom; Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, Guy's Hospital Campus, London SE1 1UL, United Kingdom
| | - Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Michelle T Ma
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Daniel R Burnham
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Samantha Y A Terry
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
| |
Collapse
|
15
|
Osytek KM, Blower PJ, Costa IM, Smith GE, Abbate V, Terry SYA. In vitro proof of concept studies of radiotoxicity from Auger electron-emitter thallium-201. EJNMMI Res 2021; 11:63. [PMID: 34224019 PMCID: PMC8257813 DOI: 10.1186/s13550-021-00802-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/03/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Auger electron-emitting radionuclides have potential in targeted treatment of small tumors. Thallium-201 (201Tl), a gamma-emitting radionuclide used in myocardial perfusion scintigraphy, decays by electron capture, releasing around 37 Auger and Coster-Kronig electrons per decay. However, its therapeutic and toxic effects in cancer cells remain largely unexplored. Here, we assess 201Tl in vitro kinetics, radiotoxicity and potential for targeted molecular radionuclide therapy, and aim to test the hypothesis that 201Tl is radiotoxic only when internalized. METHODS Breast cancer MDA-MB-231 and prostate cancer DU145 cells were incubated with 200-8000 kBq/mL [201Tl]TlCl. Potassium concentration varied between 0 and 25 mM to modulate cellular uptake of 201Tl. Cell uptake and efflux rates of 201Tl were measured by gamma counting. Clonogenic assays were used to assess cell survival after 90 min incubation with 201Tl. Nuclear DNA damage was measured with γH2AX fluorescence imaging. Controls included untreated cells and cells treated with decayed [201Tl]TlCl. RESULTS 201Tl uptake in both cell lines reached equilibrium within 90 min and washed out exponentially (t1/2 15 min) after the radioactive medium was exchanged for fresh medium. Cellular uptake of 201Tl in DU145 cells ranged between 1.6 (25 mM potassium) and 25.9% (0 mM potassium). Colony formation by both cell lines decreased significantly as 201Tl activity in cells increased, whereas 201Tl excluded from cells by use of high potassium buffer caused no significant toxicity. Non-radioactive TlCl at comparable concentrations caused no toxicity. An estimated average 201Tl intracellular activity of 0.29 Bq/cell (DU145 cells) and 0.18 Bq/cell (MDA-MB-231 cells) during 90 min exposure time caused 90% reduction in clonogenicity. 201Tl at these levels caused on average 3.5-4.6 times more DNA damage per nucleus than control treatments. CONCLUSIONS 201Tl reduces clonogenic survival and increases nuclear DNA damage only when internalized. These findings justify further development and evaluation of 201Tl therapeutic radiopharmaceuticals.
Collapse
Affiliation(s)
- Katarzyna M Osytek
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Philip J Blower
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Ines M Costa
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Gareth E Smith
- Theragnostics Limited, 2 Arlington Square, Bracknell, RG12 1WA, UK
| | - Vincenzo Abbate
- Department of Analytical, Environmental and Forensic Sciences, King's College London, London, UK.
| | - Samantha Y A Terry
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
| |
Collapse
|
16
|
Rigby A, Blower JE, Blower PJ, Terry SYA, Abbate V. Targeted Auger electron-emitter therapy: Radiochemical approaches for thallium-201 radiopharmaceuticals. Nucl Med Biol 2021; 98-99:1-7. [PMID: 33906122 PMCID: PMC7610824 DOI: 10.1016/j.nucmedbio.2021.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/25/2021] [Accepted: 03/30/2021] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Thallium-201 is a radionuclide that has previously been used clinically for myocardial perfusion scintigraphy. Although in this role it has now been largely replaced by technetium-99 m radiopharmaceuticals, thallium-201 remains attractive in the context of molecular radionuclide therapy for cancer micrometastases or single circulating tumour cells. This is due to its Auger electron (AE) emissions, which are amongst the highest in total energy and number per decay for AE-emitters. Currently, chemical platforms to achieve this potential through developing thallium-201-labelled targeted radiopharmaceuticals are not available. Here, we describe convenient methods to oxidise [201Tl]Tl(I) to chelatable [201Tl]Tl(III) and identify challenges in stable chelation of thallium to support future synthesis of effective [201Tl]-labelled radiopharmaceuticals. METHODS A plasmid pBR322 assay was carried out to determine the DNA damaging properties of [201Tl]Tl(III). A range of oxidising agents (ozone, oxygen, hydrogen peroxide, chloramine-T, iodogen, iodobeads, trichloroisocyanuric acid) and conditions (acidity, temperature) were assessed using thin layer chromatography. Chelators EDTA, DTPA and DOTA were investigated for their [201Tl]Tl(III) radiolabelling efficacy and complex stability. RESULTS Isolated plasmid studies demonstrated that [201Tl]Tl(III) can induce single and double-stranded DNA breaks. Iodo-beads, iodogen and trichloroisocyanuric acid enabled more than 95% conversion from [201Tl]Tl(I) to [201Tl]Tl(III) under conditions compatible with future biomolecule radiolabelling (mild pH, room temperature and post-oxidation removal of oxidising agent). Although chelation of [201Tl]Tl(III) was possible with EDTA, DTPA and DOTA, only radiolabeled DOTA showed good stability in serum. CONCLUSIONS Decay of [201Tl]Tl(III) in proximity to DNA causes DNA damage. Iodobeads provide a simple, mild method to convert thallium-201 from a 1+ to 3+ oxidation state and [201Tl]Tl(III) can be chelated by DOTA with moderate stability. Of the well-established chelators evaluated, DOTA is most promising for future molecular radionuclide therapy using thallium-201; nevertheless, a new generation of chelating agents offering resistance to reduction and dissociation of [201Tl]Tl(III) complexes is required.
Collapse
Affiliation(s)
- Alex Rigby
- King's College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Julia E Blower
- King's College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Philip J Blower
- King's College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Samantha Y A Terry
- King's College London, School of Biomedical Engineering and Imaging Sciences, 4th Floor Lambeth Wing, St Thomas' Hospital, London SE1 7EH, United Kingdom.
| | - Vincenzo Abbate
- King's College London, School of Population Health and Environmental Sciences, Analytical, Environmental and Forensic Sciences, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, United Kingdom.
| |
Collapse
|
17
|
Costa IM, Cheng J, Osytek KM, Imberti C, Terry SYA. Methods and techniques for in vitro subcellular localization of radiopharmaceuticals and radionuclides. Nucl Med Biol 2021; 98-99:18-29. [PMID: 33964707 PMCID: PMC7610823 DOI: 10.1016/j.nucmedbio.2021.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/18/2021] [Accepted: 03/30/2021] [Indexed: 12/28/2022]
Abstract
In oncology, the holy grail of radiotherapy is specific radiation dose deposition in tumours with minimal healthy tissue toxicity. If used appropriately, injectable, systemic radionuclide therapies could meet these criteria, even for treatment of micrometastases and single circulating tumour cells. The clinical use of α and β- particle-emitting molecular radionuclide therapies is rising, however clinical translation of Auger electron-emitting radionuclides is hampered by uncertainty around their exact subcellular localisation, which in turn affects the accuracy of dosimetry. This review aims to discuss and compare the advantages and disadvantages of various subcellular localisation methods available to localise radiopharmaceuticals and radionuclides for in vitro investigations.
Collapse
Affiliation(s)
- Ines M Costa
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom
| | - Jordan Cheng
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom
| | - Katarzyna M Osytek
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom
| | - Cinzia Imberti
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Samantha Y A Terry
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, United Kingdom.
| |
Collapse
|
18
|
Palmer TL, Tkacz-Stachowska K, Skartlien R, Omar N, Hassfjell S, Mjøs A, Bergvoll J, Brevik EM, Hjelstuen O. Microdosimetry modeling with auger emitters in generalized cell geometry. Phys Med Biol 2021; 66. [PMID: 34081028 DOI: 10.1088/1361-6560/ac01f5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 05/17/2021] [Indexed: 11/11/2022]
Abstract
A microdosimetry model was developed for the prediction of cell viability for irregular non-spherical cells that were irradiated by low energy, short range auger electrons. Measured cell survival rates for LNCaP prostate cancer were compared to the computational results for the radioisotopes177Lu and161Tb (conjugated to PSMA). The cell geometries used for the computations were derived directly from the cell culture images. A general computational approach was developed to handle arbitrary cell geometries, based on distance probability distribution functions (PDFs) derived from basic image processing. The radiation calculations were done per coarse grained PDF bin to reduce computation time, rather than on a pixel/voxel basis. The radiation dose point kernels over the full electron spectrum were derived using Monte Carlo simulations for energies below 50 eV to account for the propagation of auger electrons over length scales at and below a cellular radius. The relative importance of short range auger electrons were evaluated between the two nuclide types. The microdosimetry results were consistent with the cell viability measurements, and it was found that161Tb was more efficient than177Lu primarily due to the short range auger electrons. We foresee that imaging based microdosimetry can be used to evaluate the relative therapeutic effect between various nuclide candidates.
Collapse
Affiliation(s)
- Teresa L Palmer
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| | | | - Roar Skartlien
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| | - Nasrin Omar
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| | - Sindre Hassfjell
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| | - Andreas Mjøs
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| | - Johannes Bergvoll
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| | - Ellen M Brevik
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| | - Olaug Hjelstuen
- Institute for Energy Technology (IFE), PO Box 40, NO-2027 Kjeller, Norway
| |
Collapse
|
19
|
Pirovano G, Wilson TC, Reiner T. Auger: The future of precision medicine. Nucl Med Biol 2021; 96-97:50-53. [PMID: 33831745 PMCID: PMC8164972 DOI: 10.1016/j.nucmedbio.2021.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022]
Abstract
First reported by Lise Meitner in 1922 and independently by Pierre Auger in 1923, the Auger effect has been explored as a potential source for targeted radiotherapy. The Auger effect is based on the emission of a low energy electron (typically <25 keV) from an atom post electron capture (EC), internal conversion (IC), or incident X-rays excitation. This phenomenon can cause the emission of a primary electron and multiple electron tracks typically in the nearest proximity of the emission site (2-500 nm). The short range of the emitted Auger cascade results in medium/high levels of linear energy transfer (4-26 keV/μm) exerted on the surrounding tissue. This property makes Auger emitters the ideal candidates for delivering high levels of targeted radiation to a specific target with dimensions comparable to, for example, the DNA. By using a targeting vector such as a small molecule, peptide or antibody, one has the potential of delivering high levels of radiation to tumor specific biomarkers while circumventing off-site toxicity in healthy cells; a challenge which is harder to overcome when using other, longer range sources of radiation such as beta and alpha emitting radionuclides. Several reviews on Auger emitters have been published over the years with two recent examples. For these reviews and others, we support their analysis and therefore to avoid simple repetition, this commentary will seek to address additional aspects and viewpoints. Specifically, we will focus on those most promising preclinical and clinical studies using small molecules, peptides, antibodies and how these studies may serve as a template for future studies.
Collapse
Affiliation(s)
- Giacomo Pirovano
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Thomas C Wilson
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Thomas Reiner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Department of Radiology, Weill Cornell Medical College, New York, NY 10065, USA; Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York City, NY 10065, USA.
| |
Collapse
|
20
|
Guerra Liberal F, McMahon SJ, Prise KM. TOPAS a tool to evaluate the impact of cell geometry and radionuclide on alpha particle therapy. Biomed Phys Eng Express 2021; 7. [PMID: 33770769 DOI: 10.1088/2057-1976/abf29f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/26/2021] [Indexed: 11/11/2022]
Abstract
Due to the increasing clinical application of alpha particles, accurate assessment of their dosimetry at the cellular scale should be strongly advocated. Although observations of the impact of cell and nuclear geometry have been previously reported, this effect has not been fully quantified. Additionally, alpha particle dosimetry presents several challenges and most conventional methodologies have poor resolution and are limited to average parameters across populations of cells. Meaningful dosimetry studies with alpha particles require detailed information on the geometry of the target at a subcellular scale. METHODS The impact of cellular geometry was evaluated for 3 different scenarios, a spherical cell with a concentric nucleus, a spherical cell with an eccentric nucleus and a model of a cell attached to a flask, consisting of a hemispherical oblate ellipsoid, all exposed to 1,700 211At radionuclide decays. We also evaluated the cross-fire effect of alpha particles as function of distance to a source cell. Finally, a nanodosimetric analysis of absorbed dose to the nucleus of a cell exposed to 1 Gy of different alpha emitting radionuclides was performed. RESULTS Simulated data shows the dosimetry of self-absorbed-dose strongly depends on activity localization in the source cell, but that activity localization within the source cell did not significantly affect the cross-fire absorbed dose even when cells are in direct contact with each other. Additionally, nanodosimetric analysis failed to show any significant differences in the energy deposition profile between different alpha particle emitters. CONCLUSIONS The collected data allows a better understanding of the dosimetry of alpha particles emitters at the sub-cellular scale. Dosimetric variations between different cellular configurations can generate complications and confounding factors for the translation of dosimetric outcomes into clinical settings, but effects of different radionuclides are generally similar.
Collapse
Affiliation(s)
- Francisco Guerra Liberal
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, 97 Lisburn Rd, Belfast BT9 7AE, Belfast, BT9 7AE, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Stephen J McMahon
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, BT9 7AE, Belfast, BT9 7AE, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Kevin M Prise
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7AE, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| |
Collapse
|
21
|
Seniwal B, Bernal MA, Fonseca TC. Microdosimetric calculations for radionuclides emitting β and α particles and Auger electrons. Appl Radiat Isot 2020; 166:109302. [DOI: 10.1016/j.apradiso.2020.109302] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 06/02/2020] [Accepted: 06/17/2020] [Indexed: 11/17/2022]
|
22
|
Tang W, Tang B, Li X, Wang Y, Li Z, Gao Y, Gao H, Yan C, Sun L. Cellular S-value evaluation based on real human cell models using the GATE MC package. Appl Radiat Isot 2020; 168:109509. [PMID: 33214023 DOI: 10.1016/j.apradiso.2020.109509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 10/28/2020] [Accepted: 11/06/2020] [Indexed: 11/25/2022]
Abstract
Exploring the spatial distribution of the energy loss of ionising radiation at the subcellular level is indispensable for evaluating the radiobiological effects of targeted radionuclide therapy accurately. Believing that S-values are important for obtaining the target dose, the Committee on Medical Internal Radiation Dose (MIRD) proposed a method to obtain the cellular dosimetric parameter. However, most available data on cellular S-values were calculated based on simple geometric models, such as ellipsoids or spheres, which do not accurately reflect biological reality. To investigate the influence of the cellular model on S-values, calculations were performed for two kinds of polygon-surface phantom models of realistic, individual human cells, the lung epithelial cell model (the B2B Phantom model) and the hepatocyte model (the Liver Phantom model), using the Monte Carlo (MC) software package GATE. To analyse the influence of cell geometry on the final S-value, the differences in the S-values between the realistic cell models and simple geometric sphere and ellipsoid models with similar volumes were calculated and compared for six different combinations of source and target regions. The irradiation conditions were 0.01-1.10 MeV monoenergetic electron sources and the Auger electronic therapy nuclides Ga-67, Tc-99m, In-111, I-125 and Tl-201, which are commonly used in nuclear medicine. The S-values calculated in this study are different from the results of the simple geometry models proposed by previous researchers. Two more precise polygon-surface phantom models of realistic, individual human cells were used, which provided more accurate information about the cell dose and will be very useful for the diagnostic application of radiotherapy in the future.
Collapse
Affiliation(s)
- Wei Tang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Bo Tang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China; Department of Radiation Protection Safety, Shandong Center for Disease Control and Prevention, Jinan, 250014, China
| | - Xiang Li
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Yidi Wang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Zhanpeng Li
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Yunan Gao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Han Gao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Congchong Yan
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Liang Sun
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China.
| |
Collapse
|
23
|
Mahdi SM, Babak SB. Dosimetry study on Auger electron-emitting nuclear medicine radioisotopes in micrometer and nanometer scales using Geant4-DNA simulation. Int J Radiat Biol 2020; 96:1452-1465. [DOI: 10.1080/09553002.2020.1820608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
24
|
Chegeni N, Kouhkan E, Hussain A, Hassanvand M. The effect of the nucleus random location on the cellular S-values - Based on Geant4-DNA. Appl Radiat Isot 2020; 168:109427. [PMID: 33097380 DOI: 10.1016/j.apradiso.2020.109427] [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: 10/18/2019] [Revised: 07/23/2020] [Accepted: 09/14/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION The nucleus is the most crucial target in cell micro-dosimetry. At cell division time, cells do not have concentric geometry synchronously. This issue will be more essential for the low-energy electron emitters. This study investigates the variety of mean absorbed dose (S-value) in the non-concentric cell-nucleus model and random nucleus location within the cell. METHODS The S-values were calculated by Geant4-DNA for the cell and nucleus with different radius (with the RC/RN ratio = 1.2, 2, 3) and the cell geometry contains nuclei with varying positions inside the cell. Two important components, cytoplasm to the nucleus (N←Cy) and the cell surface to the nucleus (N←Cs) are considered in this work for mono energetic electrons (10-100 keV). To eliminate the effect of the nucleus position (during cell division) on the S-value, the nucleus location in each run was randomly selected inside the cell to represent the cell in a floating state. RESULTS As the nucleus becomes closer to the cell membrane the differences are more noticeable especially for electrons with energy less than 20 keV as for RN/RC = 1.2, 2, and 3 about 18, 70, and 200%, respectively. CONCLUSION Due to the variable position of the nucleus in cell division, using a random place defined in Geant4, the calculations are getting closer to the reality while there is not such possibility for analytical method used by MIRD.
Collapse
Affiliation(s)
- N Chegeni
- Departments of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - E Kouhkan
- Departments of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - A Hussain
- MCCPM, Medical Physics Department, 675 McDermott Ave, Winnipeg, MB, R3E 0V9, Cancer Care Manitoba, MB, Canada.
| | - M Hassanvand
- Department of Physics, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
| |
Collapse
|
25
|
Gill MR, Walker MG, Able S, Tietz O, Lakshminarayanan A, Anderson R, Chalk R, El-Sagheer AH, Brown T, Thomas JA, Vallis KA. An 111In-labelled bis-ruthenium(ii) dipyridophenazine theranostic complex: mismatch DNA binding and selective radiotoxicity towards MMR-deficient cancer cells. Chem Sci 2020; 11:8936-8944. [PMID: 33815738 PMCID: PMC7989384 DOI: 10.1039/d0sc02825h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/04/2020] [Indexed: 12/23/2022] Open
Abstract
Theranostic radionuclides that emit Auger electrons (AE) can generate highly localised DNA damage and the accompanying gamma ray emission can be used for single-photon emission computed tomography (SPECT) imaging. Mismatched DNA base pairs (mismatches) are DNA lesions that are abundant in cells deficient in MMR (mismatch mediated repair) proteins. This form of genetic instability is prevalent in the MMR-deficient subset of colorectal cancers and is a potential target for AE radiotherapeutics. Herein we report the synthesis of a mismatch DNA binding bis-ruthenium(ii) dipyridophenazine (dppz) complex that can be radiolabelled with the Auger electron emitting radionuclide indium-111 (111In). Greater stabilisation accompanied by enhanced MLCT (metal to ligand charge-transfer) luminescence of both the bis-Ru(dppz) chelator and non-radioactive indium-loaded complex was observed in the presence of a TT mismatch-containing duplex compared to matched DNA. The radioactive construct [111In]In-bisRu(dppz) ([111In][In-2]4+) targets cell nuclei and is radiotoxic towards MMR-deficient human colorectal cancer cells showing substantially less detrimental effects in a paired cell line with restored MMR function. Additional cell line studies revealed that [111In][In-2]4+ is preferentially radiotoxic towards MMR-deficient colorectal cancer cells accompanied by increased DNA damage due to 111In decay. The biodistribution of [111In][In-2]4+ in live mice was demonstrated using SPECT. These results illustrate how a Ru(ii) polypyridyl complex can incorporate mismatch DNA binding and radiometal chelation in a single molecule, generating a DNA-targeting AE radiopharmaceutical that displays selective radiotoxicity towards MMR-deficient cancer cells and is compatible with whole organism SPECT imaging.
Collapse
Affiliation(s)
- Martin R Gill
- Oxford Institute for Radiation Oncology , Department of Oncology , University of Oxford , Oxford , UK .
- Department of Chemistry , Swansea University , Swansea , Wales , UK .
| | - Michael G Walker
- Department of Chemistry , University of Sheffield , Sheffield , UK
| | - Sarah Able
- Oxford Institute for Radiation Oncology , Department of Oncology , University of Oxford , Oxford , UK .
| | - Ole Tietz
- Oxford Institute for Radiation Oncology , Department of Oncology , University of Oxford , Oxford , UK .
| | - Abirami Lakshminarayanan
- Oxford Institute for Radiation Oncology , Department of Oncology , University of Oxford , Oxford , UK .
- Chemistry Research Laboratory , Department of Chemistry , University of Oxford , Oxford OX1 3TA , UK
| | - Rachel Anderson
- Oxford Institute for Radiation Oncology , Department of Oncology , University of Oxford , Oxford , UK .
| | - Rod Chalk
- Structural Genomics Consortium , University of Oxford , Oxford , UK
| | - Afaf H El-Sagheer
- Chemistry Research Laboratory , Department of Chemistry , University of Oxford , Oxford OX1 3TA , UK
- Chemistry Branch , Department of Science and Mathematics , Faculty of Petroleum and Mining Engineering , Suez University , Suez 43721 , Egypt
| | - Tom Brown
- Chemistry Research Laboratory , Department of Chemistry , University of Oxford , Oxford OX1 3TA , UK
| | - Jim A Thomas
- Department of Chemistry , University of Sheffield , Sheffield , UK
| | - Katherine A Vallis
- Oxford Institute for Radiation Oncology , Department of Oncology , University of Oxford , Oxford , UK .
| |
Collapse
|
26
|
Belchior A, Di Maria S, Fernandes C, Vaz P, Paulo A, Raposinho P. Radiobiological and dosimetric assessment of DNA-intercalated 99mTc-complexes bearing acridine orange derivatives. EJNMMI Res 2020; 10:79. [PMID: 32661612 PMCID: PMC7359215 DOI: 10.1186/s13550-020-00663-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 06/25/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Recently, a new family of 99mTc(I)-tricarbonyl complexes bearing an acridine orange (AO) DNA targeting unit and different linkers between the Auger emitter (99mTc) and the AO moiety was evaluated for Auger therapy. Among them, 99mTc-C3 places the corresponding radionuclide at a shortest distance to DNA and produces important double strand breaks (DSB) yields in plasmid DNA providing the first evidence that 99mTc can efficiently induce DNA damage when well positioned to the double helix. Here in, we have extended the studies to human prostate cancer PC3 cells using the 99mTc-C3 and 99mTc-C5 complexes, aiming to assess how the distance to DNA influences the radiation-induced biological effects in this tumoral cell line, namely, in which concerns early and late damage effects. RESULTS Our results highlight the limited biological effectiveness of Auger electrons, as short path length radiation, with increasing distances to DNA. The evaluation of the radiation-induced biological effects was complemented with a comparative microdosimetric study based on intracellular dose values. The comparative study, between MIRD and Monte Carlo (MC) methods used to assess the cellular doses, revealed that efforts should be made in order to standardize the bioeffects modeling for DNA-incorporated Auger electron emitters. CONCLUSIONS 99mTc might not be the ideal radionuclide for Auger therapy but can be useful to validate the design of new classes of Auger-electron emitting radioconjugates. In this context, our results highlight the crucial importance of the distance of Auger electron emitters to the target DNA and encourage the development of strategies for the fine tuning of the distance to DNA for other medical radionuclides (e.g., 111In or 161Tb) in order to enhance their radiotherapeutic effects within the Auger therapy of cancer.
Collapse
Affiliation(s)
- Ana Belchior
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal.
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - Célia Fernandes
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - António Paulo
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal
| | - Paula Raposinho
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066, Bobadela LRS, Portugal.
| |
Collapse
|
27
|
Cellular S values in spindle-shaped cells: a dosimetry study on more realistic cell geometries using Geant4-DNA Monte Carlo simulation toolkit. Ann Nucl Med 2020; 34:742-756. [PMID: 32632563 DOI: 10.1007/s12149-020-01498-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 07/01/2020] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Cellular dosimetry plays a crucial role in radiobiology and evaluation of the relative merits of radiopharmaceuticals used for targeted radionuclide therapy. The present study aims to investigate the effects of various cell geometries on dosimetric characteristics of several Auger emitters distributed in different subcellular compartments using Monte Carlo simulation. METHODS The Geant4-DNA extension of the Geant4 Monte Carlo simulation toolkit was employed to calculate the mean absorbed dose per unit cumulated activity (S value) for different subcellular distributions of several Auger electron-emitting theranostic radionuclides including 99mTc, 111In, 123I, 125I, and 201Tl. The simulations were carried out in various single-cell models of liquid water including spherical, ellipsoidal, spherical spindle, and ellipsoidal spindle cell models. The latter two models which are generalized from the first two models were inspired by the morphologies of spindle-shaped (fusiform) cells, and were developed to provide more realistic modeling of this common geometry observed in many healthy and cancerous cells. RESULTS Evaluation of the S values calculated for the examined cell models reveals that the differences are small (less than 9%) for the cell ← cell, cell ← cell surface, and nucleus ← nucleus source-target combinations. However, moderate discrepancies are seen (up to 28%) when the nucleus is considered as the target, as well as the radioactivity is either internalized into the cytoplasm or bound to the cell membrane. CONCLUSIONS The findings of the present work suggest that the assumption of spherical cell geometry may provide reasonably accurate estimates of the cellular/nuclear dose for the considered Auger emitters, even for spindle-shaped cells. Of course, this approximation should be used with caution for the nucleus ← cytoplasm and nucleus ← cell surface configurations, since the S-value sensitivity to the cell geometry is somewhat significant in these cases.
Collapse
|
28
|
Bordes J, Incerti S, Mora-Ramirez E, Tranel J, Rossi C, Bezombes C, Bordenave J, Bardiès M, Brown R, Bordage MC. Monte Carlo dosimetry of a realistic multicellular model of follicular lymphoma in a context of radioimmunotherapy. Med Phys 2020; 47:5222-5234. [PMID: 32623743 DOI: 10.1002/mp.14370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 04/20/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Small-scale dosimetry studies generally consider an artificial environment where the tumors are spherical and the radionuclides are homogeneously biodistributed. However, tumor shapes are irregular and radiopharmaceutical biodistributions are heterogeneous, impacting the energy deposition in targeted radionuclide therapy. To bring realism, we developed a dosimetric methodology based on a three-dimensional in vitro model of follicular lymphoma incubated with rituximab, an anti-CD20 monoclonal antibody used in the treatment of non-Hodgkin lymphomas, which might be combined with a radionuclide. The effects of the realistic geometry and biodistribution on the absorbed dose were highlighted by comparison with literature data. Additionally, to illustrate the possibilities of this methodology, the effect of different radionuclides on the absorbed dose distribution delivered to the in vitro tumor were compared. METHODS The starting point was a model named multicellular aggregates of lymphoma cells (MALC). Three MALCs of different dimensions and their rituximab biodistribution were considered. Geometry, antibody location and concentration were extracted from selective plane illumination microscopy. Assuming antibody radiolabeling with Auger electron (125 I and 111 In) and β- particle emitters (177 Lu, 131 I and 90 Y), we simulated energy deposition in MALCs using two Monte Carlo codes: Geant4-DNA with "CPA100" physics models for Auger electron emitters and Geant4 with "Livermore" physics models for β- particle emitters. RESULTS MALCs had ellipsoid-like shapes with major radii, r, of ~0.25, ~0.5 and ~1.3 mm. Rituximab was concentrated in the periphery of the MALCs. The absorbed doses delivered by 177 Lu, 131 I and 90 Y in MALCs were compared with literature data for spheres with two types of homogeneous biodistributions (on the surface or throughout the volume). Compared to the MALCs, the mean absorbed doses delivered in spheres with surface biodistributions were between 18% and 38% lower, while with volume biodistribution they were between 15% and 29% higher. Regarding the radionuclides comparison, the relationship between MALC dimensions, rituximab biodistribution and energy released per decay impacted the absorbed doses. Despite releasing less energy, 125 I delivered a greater absorbed dose per decay than 111 In in the r ~ 0.25 mm MALC (6.78·10-2 vs 6.26·10-2 µGy·Bq-1 ·s-1 ). Similarly, the absorbed doses per decay in the r ~ 0.5 mm MALC for 177 Lu (2.41·10-2 µGy·Bq-1 ·s-1 ) and 131 I (2.46·10-2 µGy·Bq-1 ·s-1 ) are higher than for 90 Y (1.98·10-2 µGy·Bq-1 ·s-1 ). Furthermore, radionuclides releasing more energy per decay delivered absorbed dose more uniformly through the MALCs. Finally, when considering the radiopharmaceutical effective half-life, due to the biological half-life of rituximab being best matched by the physical half-life of 177 Lu and 131 I compared to 90 Y, the first two radionuclides delivered higher absorbed doses. CONCLUSION In the simulated configurations, β- emitters delivered higher and more uniform absorbed dose than Auger electron emitters. When considering radiopharmaceutical half-lives, 177 Lu and 131 I delivered absorbed doses higher than 90 Y. In view of real irradiation of MALCs, such a work may be useful to select suited radionuclides and to help explain the biological effects.
Collapse
Affiliation(s)
- Julien Bordes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Sébastien Incerti
- Université de Bordeaux, CENBG, UMR 5797, Gradignan, F-33170, France.,CNRS, IN2P3, CENBG, UMR 5797, Gradignan, F-33170, France
| | - Erick Mora-Ramirez
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Escuela de Física, CICANUM, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Jonathan Tranel
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Cédric Rossi
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,CHU Dijon, Hématologie Clinique, Hôpital François Mitterand, Dijon, 21000, France
| | - Christine Bezombes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Julie Bordenave
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Manuel Bardiès
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Richard Brown
- Institute of Nuclear Medicine, University College London, 235 Euston Road, London, NW1 2BU, UK
| | - Marie-Claude Bordage
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| |
Collapse
|
29
|
Dosimetric assessment in different tumour phenotypes with auger electron emitting radionuclides: 99mTc, 125I, 161Tb, and 177Lu. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
30
|
O'Neill E, Kersemans V, Allen PD, Terry SYA, Torres JB, Mosley M, Smart S, Lee BQ, Falzone N, Vallis KA, Konijnenberg MW, de Jong M, Nonnekens J, Cornelissen B. Imaging DNA Damage Repair In Vivo After 177Lu-DOTATATE Therapy. J Nucl Med 2020; 61:743-750. [PMID: 31757844 PMCID: PMC7198382 DOI: 10.2967/jnumed.119.232934] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/07/2019] [Indexed: 02/07/2023] Open
Abstract
Molecular radiotherapy using 177Lu-DOTATATE is a most effective treatment for somatostatin receptor-expressing neuroendocrine tumors. Despite its frequent and successful use in the clinic, little or no radiobiologic considerations are made at the time of treatment planning or delivery. On positive uptake on octreotide-based PET/SPECT imaging, treatment is usually administered as a standard dose and number of cycles without adjustment for peptide uptake, dosimetry, or radiobiologic and DNA damage effects in the tumor. Here, we visualized and quantified the extent of DNA damage response after 177Lu-DOTATATE therapy using SPECT imaging with 111In-anti-γH2AX-TAT. This work was a proof-of-principle study of this in vivo noninvasive biodosimeter with β-emitting therapeutic radiopharmaceuticals. Methods: Six cell lines were exposed to external-beam radiotherapy (EBRT) or 177Lu-DOTATATE, after which the number of γH2AX foci and the clonogenic survival were measured. Mice bearing CA20948 somatostatin receptor-positive tumor xenografts were treated with 177Lu-DOTATATE or sham-treated and coinjected with 111In-anti-γH2AX-TAT, 111In-IgG-TAT control, or vehicle. Results: Clonogenic survival after external-beam radiotherapy was cell-line-specific, indicating varying levels of intrinsic radiosensitivity. Regarding in vitro cell lines treated with 177Lu-DOTATATE, clonogenic survival decreased and γH2AX foci increased for cells expressing high levels of somatostatin receptor subtype 2. Ex vivo measurements revealed a partial correlation between 177Lu-DOTATATE uptake and γH2AX focus induction between different regions of CA20948 xenograft tumors, suggesting that different parts of the tumor may react differentially to 177Lu-DOTATATE irradiation. Conclusion:111In-anti-γH2AX-TAT allows monitoring of DNA damage after 177Lu-DOTATATE therapy and reveals heterogeneous damage responses.
Collapse
Affiliation(s)
- Edward O'Neill
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Veerle Kersemans
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - P Danny Allen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Samantha Y A Terry
- Department of Imaging Chemistry and Biology, King's College London, London, United Kingdom
| | - Julia Baguña Torres
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Michael Mosley
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Sean Smart
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Boon Quan Lee
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Nadia Falzone
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Katherine A Vallis
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Mark W Konijnenberg
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Marion de Jong
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Julie Nonnekens
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
- Department of Molecular Genetics, Erasmus MC, Rotterdam, The Netherlands; and
- Oncode Institute, Erasmus MC, Rotterdam, The Netherlands
| | - Bart Cornelissen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
31
|
Tamborino G, De Saint-Hubert M, Struelens L, Seoane DC, Ruigrok EAM, Aerts A, van Cappellen WA, de Jong M, Konijnenberg MW, Nonnekens J. Cellular dosimetry of [ 177Lu]Lu-DOTA-[Tyr 3]octreotate radionuclide therapy: the impact of modeling assumptions on the correlation with in vitro cytotoxicity. EJNMMI Phys 2020; 7:8. [PMID: 32040783 PMCID: PMC7010903 DOI: 10.1186/s40658-020-0276-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/27/2020] [Indexed: 12/23/2022] Open
Abstract
Background Survival and linear-quadratic model fitting parameters implemented in treatment planning for targeted radionuclide therapy depend on accurate cellular dosimetry. Therefore, we have built a refined cellular dosimetry model for [177Lu]Lu-DOTA-[Tyr3]octreotate (177Lu-DOTATATE) in vitro experiments, accounting for specific cell morphologies and sub-cellular radioactivity distributions. Methods Time activity curves were measured and modeled for medium, membrane-bound, and internalized activity fractions over 6 days. Clonogenic survival assays were performed at various added activities (0.1–2.5 MBq/ml). 3D microscopy images (stained for cytoplasm, nucleus, and Golgi) were used as reference for developing polygonal meshes (PM) in 3DsMax to accurately render the cellular and organelle geometry. Absorbed doses to the nucleus per decay (S values) were calculated for 3 cellular morphologies: spheres (MIRDcell), truncated cone-shaped constructive solid geometry (CSG within MCNP6.1), and realistic PM models, using Geant4-10.03. The geometrical set-up of the clonogenic survival assays was modeled, including dynamic changes in proliferation, proximity variations, and cell death. The absorbed dose to the nucleus by the radioactive source cell (self-dose) and surrounding source cells (cross-dose) was calculated applying the MIRD formalism. Finally, the correlation between absorbed dose and survival fraction was fitted using a linear dose-response curve (high α/β or fast sub-lethal damage repair half-life) for different assumptions, related to cellular shape and localization of the internalized fraction of activity. Results The cross-dose, depending on cell proximity and colony formation, is a minor (15%) contributor to the total absorbed dose. Cellular volume (inverse exponential trend), shape modeling (up to 65%), and internalized source localization (up to + 149% comparing cytoplasm to Golgi) significantly influence the self-dose to nucleus. The absorbed dose delivered to the nucleus during a clonogenic survival assay is 3-fold higher with MIRDcell compared to the polygonal mesh structures. Our cellular dosimetry model indicates that 177Lu-DOTATATE treatment might be more effective than suggested by average spherical cell dosimetry, predicting a lower absorbed dose for the same cellular survival. Dose-rate effects and heterogeneous dose delivery might account for differences in dose-response compared to x-ray irradiation. Conclusion Our results demonstrate that modeling of cellular and organelle geometry is crucial to perform accurate in vitro dosimetry.
Collapse
Affiliation(s)
- Giulia Tamborino
- Research in Dosimetric Application, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium.,Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | | | - Lara Struelens
- Research in Dosimetric Application, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
| | - Dayana C Seoane
- Research in Dosimetric Application, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
| | - Eline A M Ruigrok
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands.,Department of Experimental Urology, Erasmus MC, Rotterdam, The Netherlands
| | - An Aerts
- Radiobiology Unit, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
| | | | - Marion de Jong
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Mark W Konijnenberg
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Julie Nonnekens
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands. .,Department of Molecular Genetics, Erasmus MC, Rotterdam, The Netherlands. .,Oncode Institute, Erasmus MC, Rotterdam, The Netherlands.
| |
Collapse
|
32
|
Delivery systems exploiting natural cell transport processes of macromolecules for intracellular targeting of Auger electron emitters. Nucl Med Biol 2019; 80-81:45-56. [PMID: 31810828 DOI: 10.1016/j.nucmedbio.2019.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/24/2019] [Accepted: 11/25/2019] [Indexed: 12/17/2022]
Abstract
The presence of Auger electrons (AE) among the decay products of a number of radionuclides makes these radionuclides an attractive means for treating cancer because these short-range electrons can cause significant damage in the immediate vicinity of the decomposition site. Moreover, the extreme locality of the effect provides a potential for selective eradication of cancer cells with minimal damage to adjacent normal cells provided that the delivery of the AE emitter to the most vulnerable parts of the cell can be achieved. Few cellular compartments have been regarded as the desired target site for AE emitters, with the cell nucleus generally recognized as the preferred site for AE decay due to the extreme sensitivity of nuclear DNA to direct damage by radiation of high linear energy transfer. Thus, the advantages of AE emitters for cancer therapy are most likely to be realized by their selective delivery into the nucleus of the malignant cells. To achieve this goal, delivery systems must combine a challenging complex of properties that not only provide cancer cell preferential recognition but also cell entry followed by transport into the cell nucleus. A promising strategy for achieving this is the recruitment of natural cell transport processes of macromolecules, involved in each of the aforementioned steps. To date, a number of constructs exploiting intracellular transport systems have been proposed for AE emitter delivery to the nucleus of a targeted cell. An example of such a multifunctional vehicle that provides smart step-by-step delivery is the so-called modular nanotransporter, which accomplishes selective recognition, binding, internalization, and endosomal escape followed by nuclear import of the delivered radionuclide. The current review will focus on delivery systems utilizing various intracellular transport pathways and their combinations in order to provide efficient targeting of AE to the cancer cell nucleus.
Collapse
|
33
|
Jacquemin M, Broggio D, Franck D, Desbrée A. Development of a dosimetric model for in vitro labelled cells with β + emitters in PET tracking studies. ACTA ACUST UNITED AC 2019; 64:155015. [DOI: 10.1088/1361-6560/ab2cbe] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
34
|
Salim R, Taherparvar P. Monte Carlo single-cell dosimetry using Geant4-DNA: the effects of cell nucleus displacement and rotation on cellular S values. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2019; 58:353-371. [PMID: 30927051 DOI: 10.1007/s00411-019-00788-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Investigation of biological effects of low-dose ionizing radiation at the (sub-) cellular level, which is referred to as microdosimetry, remains a major challenge of today's radiobiology research. Monte Carlo simulation of radiation tracks can provide a detailed description of the physical processes involved in dimensions as small as the critical substructures of the cell. Hereby, in the present study, microdosimetric calculations of cellular S values for mono-energetic electrons and six Auger-emitting radionuclides were performed in single-cell models of liquid water using Geant4-DNA. The effects of displacement and rotation of the nucleus within the cell on the cellular S values were studied in spherical and ellipsoidal geometries. It was found that for the examined electron energies and radionuclides, in the case of nucleus cross-absorption where the radioactivity is either localized in the cytoplasm of the cell or distributed on the cell surface, rotation of the nucleus within the cell affects cellular S values less than displacement of the nucleus. Especially, the considerable differences observed in S(nucleus ← cell surface) values between an eccentric and a concentric cell-nucleus configuration in spherical and ellipsoidal geometries (up to 63% and up to 44%, respectively) suggests that the approximation of concentricity should be used with caution, at least for localized irradiation of the cell membrane by an Auger-emitter in targeted radionuclide cancer therapy. The obtained results, which are based on a more realistic modeling of the cell than was done before, provide more accurate information about nuclear dose. This can be useful for theranostic applications.
Collapse
Affiliation(s)
- Ramak Salim
- Department of Physics, Faculty of Science, University of Guilan, Namjoo Avenue, P.O. Box 41335-19141, Rasht, 4193833697, Iran
| | - Payvand Taherparvar
- Department of Physics, Faculty of Science, University of Guilan, Namjoo Avenue, P.O. Box 41335-19141, Rasht, 4193833697, Iran.
| |
Collapse
|
35
|
Falzone N, Gregory R, Aldridge M, Terry SY, Flux G. Clinical trials in molecular radiotherapy-Tribulations and Triumphs Report of the NCRI CTRad meeting held at the Lift Islington, 8 June 2018. Br J Radiol 2019; 92:20190117. [PMID: 30982344 DOI: 10.1259/bjr.20190117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It has been almost a decade since the commentary Molecular radiotherapy - the radionuclide raffle? by Gaze and Flux (2010) . The overarching feeling then was that no individual or organisation has taken up the challenge, nationally or internationally, of championing molecular targeted radionuclide therapy in all its aspects. Here, we report on the recent NCRI-CTRad (Clinical Trials in Molecular Radiotherapy-Tribulations and Triumphs) meeting, held in London on the 8 June 2018. The meeting was organized by the NCRI-CTRad to review the challenges and opportunities for clinical trials in molecular radiotherapy, particularly focussing on investigator-led trials that incorporate imaging and dosimetry, and to discuss how the community can move forward. This meeting was organised in conjunction with the British Nuclear Medicine Society and reflects the progress of Nuclear Medicine in the UK.
Collapse
Affiliation(s)
- Nadia Falzone
- 1 CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, UK
| | - Rebecca Gregory
- 2 Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK
| | - Matthew Aldridge
- 3 University College London Hospitals NHS Foundation Trust, London, UK
| | - Samantha Ya Terry
- 4 Department of Imaging Chemistry and Biology, School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK
| | - Glenn Flux
- 2 Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK
| |
Collapse
|
36
|
Cova TFGG, Bento DJ, Nunes SCC. Computational Approaches in Theranostics: Mining and Predicting Cancer Data. Pharmaceutics 2019; 11:E119. [PMID: 30871264 PMCID: PMC6471740 DOI: 10.3390/pharmaceutics11030119] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/26/2019] [Accepted: 03/07/2019] [Indexed: 02/02/2023] Open
Abstract
The ability to understand the complexity of cancer-related data has been prompted by the applications of (1) computer and data sciences, including data mining, predictive analytics, machine learning, and artificial intelligence, and (2) advances in imaging technology and probe development. Computational modelling and simulation are systematic and cost-effective tools able to identify important temporal/spatial patterns (and relationships), characterize distinct molecular features of cancer states, and address other relevant aspects, including tumor detection and heterogeneity, progression and metastasis, and drug resistance. These approaches have provided invaluable insights for improving the experimental design of therapeutic delivery systems and for increasing the translational value of the results obtained from early and preclinical studies. The big question is: Could cancer theranostics be determined and controlled in silico? This review describes the recent progress in the development of computational models and methods used to facilitate research on the molecular basis of cancer and on the respective diagnosis and optimized treatment, with particular emphasis on the design and optimization of theranostic systems. The current role of computational approaches is providing innovative, incremental, and complementary data-driven solutions for the prediction, simplification, and characterization of cancer and intrinsic mechanisms, and to promote new data-intensive, accurate diagnostics and therapeutics.
Collapse
Affiliation(s)
- Tânia F G G Cova
- Coimbra Chemistry Centre, Department of Chemistry, Faculty of Sciences and Technology, University of Coimbra, 3004-535 Coimbra, Portugal.
| | - Daniel J Bento
- Coimbra Chemistry Centre, Department of Chemistry, Faculty of Sciences and Technology, University of Coimbra, 3004-535 Coimbra, Portugal.
| | - Sandra C C Nunes
- Coimbra Chemistry Centre, Department of Chemistry, Faculty of Sciences and Technology, University of Coimbra, 3004-535 Coimbra, Portugal.
| |
Collapse
|
37
|
Micro-dosimetry calculation of Auger-electron-emitting radionuclides mostly used in nuclear medicine using GEANT4-DNA. Appl Radiat Isot 2018; 141:73-79. [DOI: 10.1016/j.apradiso.2018.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 08/20/2018] [Accepted: 08/21/2018] [Indexed: 11/20/2022]
|
38
|
Bavelaar BM, Lee BQ, Gill MR, Falzone N, Vallis KA. Subcellular Targeting of Theranostic Radionuclides. Front Pharmacol 2018; 9:996. [PMID: 30233374 PMCID: PMC6131480 DOI: 10.3389/fphar.2018.00996] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022] Open
Abstract
The last decade has seen rapid growth in the use of theranostic radionuclides for the treatment and imaging of a wide range of cancers. Radionuclide therapy and imaging rely on a radiolabeled vector to specifically target cancer cells. Radionuclides that emit β particles have thus far dominated the field of targeted radionuclide therapy (TRT), mainly because the longer range (μm-mm track length) of these particles offsets the heterogeneous expression of the molecular target. Shorter range (nm-μm track length) α- and Auger electron (AE)-emitting radionuclides on the other hand provide high ionization densities at the site of decay which could overcome much of the toxicity associated with β-emitters. Given that there is a growing body of evidence that other sensitive sites besides the DNA, such as the cell membrane and mitochondria, could be critical targets in TRT, improved techniques in detecting the subcellular distribution of these radionuclides are necessary, especially since many β-emitting radionuclides also emit AE. The successful development of TRT agents capable of homing to targets with subcellular precision demands the parallel development of quantitative assays for evaluation of spatial distribution of radionuclides in the nm-μm range. In this review, the status of research directed at subcellular targeting of radionuclide theranostics and the methods for imaging and quantification of radionuclide localization at the nanoscale are described.
Collapse
Affiliation(s)
| | | | | | | | - Katherine A. Vallis
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
39
|
Falzone N, Lee BQ, Able S, Malcolm J, Terry S, Alayed Y, Vallis KA. Targeting Micrometastases: The Effect of Heterogeneous Radionuclide Distribution on Tumor Control Probability. J Nucl Med 2018; 60:jnumed.117.207308. [PMID: 29959216 PMCID: PMC6330061 DOI: 10.2967/jnumed.117.207308] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/07/2018] [Indexed: 12/12/2022] Open
Abstract
The spatial distribution of radiopharmaceuticals that emit short-range high linear-energy-transfer electrons greatly affects the absorbed dose and their biological effectiveness. The purpose of this study was to investigate the effect of heterogeneous radionuclide distribution on tumor control probability (TCP) in a micrometastases model. Methods: Cancer cell lines; MDA-MB-468, SQ20B and 231-H2N were grown as spheroids to represent micrometastases. The intracellular distribution of a representative radiopeptide (111In-labelled epidermal growth factor, EGF) and radioimmunotherapeutic (111In-labelled Trastuzumab) was determined in cell internalization experiments. The intratumoral distribution was evaluated by microautoradiography of spheroids. γH2AX staining was performed on spheroid sections to correlate DNA damage with radionuclide distribution. Experimental surviving fractions (SFexp ) were obtained using clonogenic assays. A random closed-packed algorithm, which models the random packing behavior of cells and reflects variation in the radii of cells and nuclei, was used to simulate 3-D spheroids. Calculated survival fractions (SFcal ) were generated using an iterative modelling method based on Monte Carlo determined absorbed dose with the PENELOPE code and were compared to (SFexp ). Radiobiological parameters deduced from experimental results and MC simulations were used to predict the TCP for a 3-D spheroid model. Results: Calculated SFs were in good agreement with experimental data, particularly when an increased value for relative biological effectiveness (RBE) was applied to self-dose deposited by sources located in the nucleus and when radiobiological parameters were adjusted to account for dose protraction. Only in MDA-MB-468 spheroids treated with 111In-EGF was a TCP>0.5 achieved, indicating that for this cell type the radiopeptide would be curative when targeting micrometastases. This is attributed to the relative radiosensitivity of MDA-MB-468 cells, high nuclear uptake of the radiopeptide and uniform distribution of radioactivity throughout the spheroid. Conclusion: It is imperative to include biological endpoints when evaluating the distribution of radionuclides in models emulating micrometastatic disease. The spatial distribution of radioactivity is a clear determinant of biological effect and TCP as demonstrated in this study.
Collapse
Affiliation(s)
- Nadia Falzone
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, United Kingdom; and
| | - Boon Quan Lee
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, United Kingdom; and
| | - Sarah Able
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, United Kingdom; and
| | - Javian Malcolm
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, United Kingdom; and
| | - Samantha Terry
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, United Kingdom; and
- Imaging Chemistry and Biology, King’s College London, London, United Kingdom
| | - Yasir Alayed
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, United Kingdom; and
| | - Katherine A. Vallis
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford University, Oxford, United Kingdom; and
| |
Collapse
|
40
|
Lee D, Li M, Bednarz B, Schultz MK. Modeling Cell and Tumor-Metastasis Dosimetry with the Particle and Heavy Ion Transport Code System (PHITS) Software for Targeted Alpha-Particle Radionuclide Therapy. Radiat Res 2018; 190:236-247. [PMID: 29944461 DOI: 10.1667/rr15081.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The use of targeted radionuclide therapy for cancer is on the rise. While beta-particle-emitting radionuclides have been extensively explored for targeted radionuclide therapy, alpha-particle-emitting radionuclides are emerging as effective alternatives. In this context, fundamental understanding of the interactions and dosimetry of these emitted particles with cells in the tumor microenvironment is critical to ascertaining the potential of alpha-particle-emitting radionuclides. One important parameter that can be used to assess these metrics is the S-value. In this study, we characterized several alpha-particle-emitting radionuclides (and their associated radionuclide progeny) regarding S-values in the cellular and tumor-metastasis environments. The Particle and Heavy Ion Transport code System (PHITS) was used to obtain S-values via Monte Carlo simulation for cell and tumor metastasis resulting from interactions with the alpha-particle-emitting radionuclides, lead-212 (212Pb), actinium-225 (225Ac) and bismuth-213 (213Bi); these values were compared to the beta-particle-emitting radionuclides yttrium-90 (90Y) and lutetium-177 (177Lu) and an Auger-electron-emitting radionuclide indium-111 (111In). The effect of cellular internalization on S-value was explored at increasing degree of internalization for each radionuclide. This aspect of S-value determination was further explored in a cell line-specific fashion for six different cancer cell lines based on the cell dimensions obtained by confocal microscopy. S-values from PHITS were in good agreement with MIRDcell S-values (cellular S-values) and the values found by Hindié et al. (tumor S-values). In the cellular model, 212Pb and 213Bi decay series produced S-values that were 50- to 120-fold higher than 177Lu, while 225Ac decay series analysis suggested S-values that were 240- to 520-fold higher than 177Lu. S-values arising with 100% cellular internalization were two- to sixfold higher for the nucleus when compared to 0% internalization. The tumor dosimetry model defines the relative merit of radionuclides and suggests alpha particles may be effective for large tumors as well as small tumor metastases. These results from PHITS modeling substantiate emerging evidence that alpha-particle-emitting radionuclides may be an effective alternative to beta-particle-emitting radionuclides for targeted radionuclide therapy due to preferred dose-deposition profiles in the cellular and tumor metastasis context. These results further suggest that internalization of alpha-particle-emitting radionuclides via radiolabeled ligands may increase the relative biological effectiveness of radiotherapeutics.
Collapse
Affiliation(s)
- Dongyoul Lee
- a Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, Iowa
| | - Mengshi Li
- a Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, Iowa
| | - Bryan Bednarz
- b Department of Medical Physics, University of Wisconsin, Madison, Wisconsin
| | - Michael K Schultz
- a Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, Iowa.,c Stead Family Department of Pediatrics, Carver College of Medicine, The University of Iowa, Iowa City, Iowa.,d Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa.,e Department of Radiation Oncology (Free Radical and Radiation Biology Program), Carver College of Medicine, The University of Iowa, Iowa City, Iowa.,f Department of Chemistry, The University of Iowa, Iowa City, Iowa.,g Viewpoint Molecular Targeting, LLC, Coralville, Iowa
| |
Collapse
|
41
|
Incerti S, Kyriakou I, Bernal MA, Bordage MC, Francis Z, Guatelli S, Ivanchenko V, Karamitros M, Lampe N, Lee SB, Meylan S, Min CH, Shin WG, Nieminen P, Sakata D, Tang N, Villagrasa C, Tran HN, Brown JMC. Geant4-DNA example applications for track structure simulations in liquid water: A report from the Geant4-DNA Project. Med Phys 2018; 45. [PMID: 29901835 DOI: 10.1002/mp.13048] [Citation(s) in RCA: 204] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/03/2018] [Accepted: 06/04/2018] [Indexed: 01/11/2023] Open
Abstract
This Special Report presents a description of Geant4-DNA user applications dedicated to the simulation of track structures (TS) in liquid water and associated physical quantities (e.g., range, stopping power, mean free path…). These example applications are included in the Geant4 Monte Carlo toolkit and are available in open access. Each application is described and comparisons to recent international recommendations are shown (e.g., ICRU, MIRD), when available. The influence of physics models available in Geant4-DNA for the simulation of electron interactions in liquid water is discussed. Thanks to these applications, the authors show that the most recent sets of physics models available in Geant4-DNA (the so-called "option4" and "option 6" sets) enable more accurate simulation of stopping powers, dose point kernels, and W-values in liquid water, than the default set of models ("option 2") initially provided in Geant4-DNA. They also serve as reference applications for Geant4-DNA users interested in TS simulations.
Collapse
Affiliation(s)
- S Incerti
- University of Bordeaux, CENBG, UMR 5797, F-33170, Gradignan, France
- CNRS, IN2P3, CENBG, UMR 5797, F-33170, Gradignan, France
| | - I Kyriakou
- Medical Physics Laboratory, University of Ioannina Medical School, 45110, Ioannina, Greece
| | - M A Bernal
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - M C Bordage
- Université Toulouse III-Paul Sabatier, UMR1037 CRCT, Toulouse, France
- Inserm, UMR1037 CRCT, Toulouse, France
| | - Z Francis
- Department of Physics, Faculty of Sciences, Université Saint Joseph, Beirut, Lebanon
| | - S Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
- Illawarra Health & Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - V Ivanchenko
- Geant4 Associates International Ltd., Hebden Bridge, UK
- Tomsk State University, Tomsk, Russia
| | - M Karamitros
- Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA
| | - N Lampe
- Vicinity Centres, Data Science & Insights, Office Tower One, 1341 Dandenong Rd, Chadstone, Victoria, 3148, Australia
| | - S B Lee
- Proton Therapy Center, National Cancer Center, 323, Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do, Korea
| | - S Meylan
- SymAlgo Technologies, 75 rue Léon Frot, 75011, Paris, France
| | - C H Min
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Korea
| | - W G Shin
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Korea
| | | | - D Sakata
- University of Bordeaux, CENBG, UMR 5797, F-33170, Gradignan, France
- CNRS, IN2P3, CENBG, UMR 5797, F-33170, Gradignan, France
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - N Tang
- IRSN, Institut de Radioprotection et de Sureté Nucléaire, 92262, Fontenay-aux-Roses, France
| | - C Villagrasa
- IRSN, Institut de Radioprotection et de Sureté Nucléaire, 92262, Fontenay-aux-Roses, France
| | - H N Tran
- Division of Nuclear Physics, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - J M C Brown
- Department of Radiation Science and Technology, Delft University of Technology, Delft, The Netherlands
| |
Collapse
|
42
|
Di Maria S, Belchior A, Romanets Y, Paulo A, Vaz P. Monte Carlo dose distribution calculation at nuclear level for Auger-emitting radionuclide energies. Appl Radiat Isot 2018; 135:72-77. [DOI: 10.1016/j.apradiso.2018.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 11/26/2017] [Accepted: 01/12/2018] [Indexed: 02/02/2023]
|
43
|
Miran T, Vogg ATJ, Drude N, Mottaghy FM, Morgenroth A. Modulation of glutathione promotes apoptosis in triple-negative breast cancer cells. FASEB J 2018; 32:2803-2813. [PMID: 29301945 DOI: 10.1096/fj.201701157r] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Triple-negative breast cancer has an extremely high rate of relapse. This is particularly due to the existence and survival of cancer stem cells (CSCs) characterized by increased amounts of glutathione (GSH). In this study, we evaluated the potential of pharmacological GSH depletion to sensitize CSCs to ionizing radiotherapy with an I-125-labeled nucleoside analog, 5-iodo-4'-thio-2'-deoxyuridine (ITdU). CSCs were isolated using CD24-- and CD44+-specific microbeads. GSH and reactive oxygen species (ROS) were evaluated by fluorescence-activated cell sorting. GSH synthesis was inhibited with buthionine sulfoximine (BSO). Apoptotic cells were identified with propidium iodide and double-strand DNA breaks were detected by γ-H2AX staining. For therapy study, BSO treated and untreated mice xenografted with breast CSCs received weekly I-125-ITdU. Therapy efficiency was monitored by fluorodeoxyglucose-18-µ-positron emission tomography. We showed that GSH modulation sensitizes CD24- and CD44+ breast cancer cells to endogenous nanoradiotherapy. BSO synergistically affects ROS generation induced by I-125-ITdU. In an in vivo study, we demonstrated a complete tumor regression as a consequence of preconditioning with a GSH-synthesis inhibitor prior to treatment with I-125-ITdU. GSH modulation in combination with an oxidative stress-generating treatment such as endogenous radiotherapy using an Auger emitter offers an extraordinary opportunity for selective and efficient eradication of drug-resistant CSCs.-Miran, T., Vogg, A. T. J., Drude, N., Mottaghy, F. M., Morgenroth, A. Modulation of glutathione promotes apoptosis in triple-negative breast cancer cells.
Collapse
Affiliation(s)
- Tara Miran
- Department of Nuclear Medicine, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Andreas T J Vogg
- Department of Nuclear Medicine, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Natascha Drude
- Department of Nuclear Medicine, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Felix M Mottaghy
- Department of Nuclear Medicine, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany.,Department of Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Agnieszka Morgenroth
- Department of Nuclear Medicine, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| |
Collapse
|
44
|
Di Maria S, Belchior A, Pereira E, Quental L, Oliveira M, Mendes F, Lavrado J, Paulo A, Vaz P. Dosimetry assessment of DNA damage by Auger-emitting radionuclides: Experimental and Monte Carlo studies. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.01.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
45
|
Raghavan R, Howell RW, Zalutsky MR. A model for optimizing delivery of targeted radionuclide therapies into resection cavity margins for the treatment of primary brain cancers. Biomed Phys Eng Express 2017; 3:035005. [PMID: 29081990 PMCID: PMC5658137 DOI: 10.1088/2057-1976/aa6db9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Radionuclides conjugated to molecules that bind specifically to cancer cells are of great interest as a means to increase the specificity of radiotherapy. Currently, the methods to disseminate these targeted radiotherapeutics have been either systemic delivery or by bolus injection into the tumor or tumor resection cavity. Herein we model a potentially more efficient method of delivery, namely pressure-driven fluid flow, called convection-enhanced delivery (CED), where a device infuses the molecules in solution (or suspension) directly into the tissue of interest. In particular, we focus on the setting of primary brain cancer after debulking surgery, where the tissue margins surrounding the surgical resection cavity are infiltrated with tumor cells and the most frequent sites of tumor recurrence. We develop the combination of fluid flow, chemical kinetics, and radiation dose models needed to examine such protocols. We focus on Auger electron-emitting radionuclides (e.g. 67Ga, 77Br, 111In, 125I, 123I, 193mPt, 195mPt) whose short range makes them ideal for targeted therapy in this setting of small foci of tumor spread within normal tissue. By solving these model equations, we confirm that a CED protocol is promising in allowing sufficient absorbed dose to destroy cancer cells with minimal absorbed dose to normal cells at clinically feasible activity levels. We also show that Auger emitters are ideal for this purpose while the longer range alpha particle emitters fail to meet criteria for effective therapy (as neither would energetic beta particle emitters). The model is used with simplified assumptions on the geometry and homogeneity of brain tissue to allow semi-analytic solutions to be displayed, and with the purpose of a first examination of this new delivery protocol proposed for radionuclide therapy. However, we emphasize that it is immediately extensible to personalized therapy treatment planning as we have previously shown for conventional CED, at the price of requiring a fully numerical computerized approach.
Collapse
Affiliation(s)
- Raghu Raghavan
- Therataxis, LLC, JHU Eastern Complex, Suite B305, 1101 E. 33rd St., Baltimore MD 21218, United States of America
| | - Roger W Howell
- Division of Radiation Research, Department of Radiology, New Jersey Medical School Cancer Center. Rutgers, The State Univeristy of New Jersey, 205 S. Orange Ave, Newark, NJ 07103, United States of America
| | - Michael R Zalutsky
- Department of Radiology, Duke University Medical Center, 311 Research Drive, Durham, NC27710, United States of America
| |
Collapse
|
46
|
Falzone N, Lee BQ, Fernández-Varea JM, Kartsonaki C, Stuchbery AE, Kibédi T, Vallis KA. Absorbed dose evaluation of Auger electron-emitting radionuclides: impact of input decay spectra on dose point kernels and S-values. Phys Med Biol 2017; 62:2239-2253. [PMID: 28102829 DOI: 10.1088/1361-6560/aa5aa4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The aim of this study was to investigate the impact of decay data provided by the newly developed stochastic atomic relaxation model BrIccEmis on dose point kernels (DPKs - radial dose distribution around a unit point source) and S-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE) emitting radionuclides, namely 67Ga, 80mBr, 89Zr, 90Nb, 99mTc, 111In, 117mSn, 119Sb, 123I, 124I, 125I, 135La, 195mPt and 201Tl. Radiation spectra were based on the nuclear decay data from the medical internal radiation dose (MIRD) RADTABS program and the BrIccEmis code, assuming both an isolated-atom and condensed-phase approach. DPKs were simulated with the PENELOPE Monte Carlo (MC) code using event-by-event electron and photon transport. S-values for concentric spherical cells of various sizes were derived from these DPKs using appropriate geometric reduction factors. The number of Auger and Coster-Kronig (CK) electrons and x-ray photons released per nuclear decay (yield) from MIRD-RADTABS were consistently higher than those calculated using BrIccEmis. DPKs for the electron spectra from BrIccEmis were considerably different from MIRD-RADTABS in the first few hundred nanometres from a point source where most of the Auger electrons are stopped. S-values were, however, not significantly impacted as the differences in DPKs in the sub-micrometre dimension were quickly diminished in larger dimensions. Overestimation in the total AE energy output by MIRD-RADTABS leads to higher predicted energy deposition by AE emitting radionuclides, especially in the immediate vicinity of the decaying radionuclides. This should be taken into account when MIRD-RADTABS data are used to simulate biological damage at nanoscale dimensions.
Collapse
Affiliation(s)
- Nadia Falzone
- Department of Oncology, CR-UK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom. Department of Biomedical Science, Tshwane University of Technology, Pretoria, South Africa
| | | | | | | | | | | | | |
Collapse
|
47
|
Pereira E, do Quental L, Palma E, Oliveira MC, Mendes F, Raposinho P, Correia I, Lavrado J, Di Maria S, Belchior A, Vaz P, Santos I, Paulo A. Evaluation of Acridine Orange Derivatives as DNA-Targeted Radiopharmaceuticals for Auger Therapy: Influence of the Radionuclide and Distance to DNA. Sci Rep 2017; 7:42544. [PMID: 28211920 PMCID: PMC5304164 DOI: 10.1038/srep42544] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/09/2017] [Indexed: 01/01/2023] Open
Abstract
A new family of 99mTc(I)- tricarbonyl complexes and 125I-heteroaromatic compounds bearing an acridine orange (AO) DNA targeting unit was evaluated for Auger therapy. Characterization of the DNA interaction, performed with the non-radioactive Re and 127I congeners, confirmed that all compounds act as DNA intercalators. Both classes of compounds induce double strand breaks (DSB) in plasmid DNA but the extent of DNA damage is strongly dependent on the linker between the Auger emitter (99mTc or 125I) and the AO moiety. The in vitro evaluation was complemented with molecular docking studies and Monte Carlo simulations of the energy deposited at the nanometric scale, which corroborated the experimental data. Two of the tested compounds, 125I-C5 and 99mTc-C3, place the corresponding radionuclide at similar distances to DNA and produce comparable DSB yields in plasmid and cellular DNA. These results provide the first evidence that 99mTc can induce DNA damage with similar efficiency to that of 125I, when both are positioned at comparable distances to the double helix. Furthermore, the high nuclear retention of 99mTc-C3 in tumoral cells suggests that 99mTc-labelled AO derivatives are more promising for the design of Auger-emitting radiopharmaceuticals than the 125I-labelled congeners.
Collapse
Affiliation(s)
- Edgar Pereira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Letícia do Quental
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Elisa Palma
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal.,Centro Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal
| | - Maria Cristina Oliveira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Filipa Mendes
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Paula Raposinho
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Isabel Correia
- Centro Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal
| | - João Lavrado
- iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Ana Belchior
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - Isabel Santos
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - António Paulo
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| |
Collapse
|
48
|
Evans-Axelsson S, Timmermand OV, Bjartell A, Strand SE, Elgqvist J. Radioimmunotherapy for Prostate Cancer--Current Status and Future Possibilities. Semin Nucl Med 2016; 46:165-79. [PMID: 26897720 DOI: 10.1053/j.semnuclmed.2015.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Prostate cancer (PCa) is one of the most common cancers in men and is the second leading cause of cancer-related deaths in the USA. In the United States, it is the second most frequently diagnosed cancer after skin cancer, and in Europe it is number one. According to the American Cancer Society, approximately 221,000 men in the United States would be diagnosed with PCa during 2015, and approximately 28,000 would die of the disease. According to the International Agency for Research on Cancer, approximately 345,000 men were diagnosed with PCa in Europe during 2012, and despite more emphasis placed on early detection through routine screening, 72,000 men died of the disease. Hence, the need for improved therapy modalities is of utmost importance. And targeted therapies based on radiolabeled specific antibodies or peptides are a very interesting and promising alternative to increase the therapeutic efficacy and overall chance of survival of these patients. There are currently several preclinical and some clinical studies that have been conducted, or are ongoing, to investigate the therapeutic efficacy and toxicity of radioimmunotherapy (RIT) against PCa. One thing that is lacking in a lot of these published studies is the dosimetry data, which are needed to compare results between the studies and the study locations. Given the complicated tumor microenvironment and overall complexity of RIT to PCa, old and new targets and targeting strategies like combination RIT and pretargeting RIT are being improved and assessed along with various therapeutic radionuclides candidates. Given alone or in combination with other therapies, these new and improved strategies and RIT tools further enhance the clinical response to RIT drugs in PCa, making RIT for PCa an increasingly practical clinical tool.
Collapse
Affiliation(s)
- Susan Evans-Axelsson
- Department of Translational Medicine, Division of Urological Cancers, Skåne University Hospital, Malmö, Lund University, Lund, Sweden
| | | | - Anders Bjartell
- Department of Translational Medicine, Division of Urological Cancers, Skåne University Hospital, Malmö, Lund University, Lund, Sweden; Department of Urology, Skåne University Hospital, Malmö, Sweden
| | - Sven-Erik Strand
- Department of Clinical Sciences, Lund, Division of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Jörgen Elgqvist
- Department of Clinical Sciences, Lund, Division of Medical Radiation Physics, Lund University, Lund, Sweden.
| |
Collapse
|
49
|
Cai Z, Kwon YL, Reilly RM. Monte Carlo N-Particle (MCNP) Modeling of the Cellular Dosimetry of 64Cu: Comparison with MIRDcell S Values and Implications for Studies of Its Cytotoxic Effects. J Nucl Med 2016; 58:339-345. [PMID: 27660146 DOI: 10.2967/jnumed.116.175695] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 09/01/2016] [Indexed: 12/18/2022] Open
Abstract
64Cu emits positrons as well as β- particles and Auger and internal conversion electrons useful for radiotherapy. Our objective was to model the cellular dosimetry of 64Cu under different geometries commonly used to study the cytotoxic effects of 64Cu. METHODS Monte Carlo N-Particle (MCNP) was used to simulate the transport of all particles emitted by 64Cu from the cell surface (CS), cytoplasm (Cy), or nucleus (N) of a single cell; monolayer in a well (radius = 0.32-1.74 cm); or a sphere (radius = 50-6,000 μm) of cells to calculate S values. The radius of the cell and N ranged from 5 to 12 μm and 2 to 11 μm, respectively. S values were obtained by MIRDcell for comparison. MCF7/HER2-18 cells were exposed in vitro to 64Cu-labeled trastuzumab. The subcellular distribution of 64Cu was measured by cell fractionation. The surviving fraction was determined in a clonogenic assay. RESULTS The relative differences of MCNP versus MIRDcell self-dose S values (Sself) for 64Cu ranged from -0.2% to 3.6% for N to N (SN←N), 2.3% to 8.6% for Cy to N (SN←Cy), and -12.0% to 7.3% for CS to N (SN←CS). The relative differences of MCNP versus MIRDcell cross-dose S values were 25.8%-30.6% for a monolayer and 30%-34% for a sphere, respectively. The ratios of SN←N versus SN←Cy and SN←Cy versus SN←CS decreased with increasing ratio of the N of the cell versus radius of the cell and the size of the monolayer or sphere. The surviving fraction of MCF7 /: HER2-18 cells treated with 64Cu-labeled trastuzumab (0.016-0.368 MBq/μg, 67 nM) for 18 h versus the absorbed dose followed a linear survival curve with α = 0.51 ± 0.05 Gy-1 and R2 = 0.8838. This is significantly different from the linear quadratic survival curve of MCF7 /: HER2-18 cells exposed to γ-rays. CONCLUSION MCNP- and MIRDcell-calculated S values agreed well. 64Cu in the N increases the dose to the N in isolated single cells but has less effect in a cell monolayer or small cluster of cells simulating a micrometastasis, and little effect in a sphere analogous to a tumor xenograft compared with 64Cu in the Cy or on the CS. The dose deposited by 64Cu is less effective for cell killing than γ-rays.
Collapse
Affiliation(s)
- Zhongli Cai
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Yongkyu Luke Kwon
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario, Canada .,Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.,Toronto General Research Institute, Toronto, Ontario, Canada; and.,Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| |
Collapse
|
50
|
Lee BQ, Nikjoo H, Ekman J, Jönsson P, Stuchbery AE, Kibédi T. A stochastic cascade model for Auger-electron emitting radionuclides. Int J Radiat Biol 2016; 92:641-653. [PMID: 27010453 DOI: 10.3109/09553002.2016.1153810] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
To benchmark a Monte Carlo model of the Auger cascade that has been developed at the Australian National University (ANU) against the literature data. The model is applicable to any Auger-electron emitting radionuclide with nuclear structure data in the format of the Evaluated Nuclear Structure Data File (ENSDF). Schönfeld's algorithms and the BrIcc code were incorporated to obtain initial vacancy distributions due to electron capture (EC) and internal conversion (IC), respectively. Atomic transition probabilities were adopted from the Evaluated Atomic Data Library (EADL) for elements with atomic number, Z = 1-100. Atomic transition energies were evaluated using a relativistic Dirac-Fock method. An energy-restriction protocol was implemented to eliminate energetically forbidden transitions from the simulations. Calculated initial vacancy distributions and average energy spectra of 123I, 124I, and 125I were compared with the literature data. In addition, simulated kinetic energy spectra and frequency distributions of the number of emitted electrons and photons of the three iodine radionuclides are presented. Some examples of radiation spectra of individual decays are also given. Good agreement with the published data was achieved except for the outer-shell Auger and Coster-Kronig transitions. Nevertheless, the model needs to be compared with experimental data in a future study.
Collapse
Affiliation(s)
- Boon Q Lee
- a Department of Nuclear Physics , Research School of Physics and Engineering, The Australian National University , Canberra , Australia
| | - Hooshang Nikjoo
- b Department of Oncology-Pathology , Karolinska Institutet , Stockholm , Sweden
| | - Jörgen Ekman
- c Materials Science and Applied Mathematics , Malmö University , Malmö , Sweden
| | - Per Jönsson
- c Materials Science and Applied Mathematics , Malmö University , Malmö , Sweden
| | - Andrew E Stuchbery
- a Department of Nuclear Physics , Research School of Physics and Engineering, The Australian National University , Canberra , Australia
| | - Tibor Kibédi
- a Department of Nuclear Physics , Research School of Physics and Engineering, The Australian National University , Canberra , Australia
| |
Collapse
|