1
|
Katugampola S, Hobbs RF, Howell RW. Generalized methods for predicting biological response to mixed radiation types and calculating equieffective doses (EQDX). Med Phys 2024; 51:637-649. [PMID: 37558637 DOI: 10.1002/mp.16650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/23/2023] [Accepted: 07/10/2023] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND Predicting biological responses to mixed radiation types is of considerable importance when combining radiation therapies that use multiple radiation types and delivery regimens. These may include the use of both low- and high-linear energy transfer (LET) radiations. A number of theoretical models have been developed to address this issue. However, model predictions do not consistently match published experimental data for mixed radiation exposures. Furthermore, the models are often computationally intensive. Accordingly, there is a need for efficient analytical models that can predict responses to mixtures of low- and high-LET radiations. Additionally, a general formalism to calculate equieffective dose (EQDX) for mixed radiations is needed. PURPOSE To develop a computationally efficient analytical model that can predict responses to complex mixtures of low- and high-LET radiations as a function of either absorbed dose or EQDX. METHODS The Zaider-Rossi model (ZRM) was modified by replacing the geometric mean of the quadratic coefficients in the interaction term with the arithmetic mean. This modified ZRM model (mZRM) was then further generalized to any number of radiation types and its validity was tested against published experimental observations. Comparisons between the predictions of the ZRM and mZRM, and other models, were made using two and three radiation types. In addition, a generalized formalism for calculating EQDX for mixed radiations was developed within the context of mZRM and validated with published experimental results. RESULTS The predictions of biological responses to mixed-LET radiations calculated with the mZRM are in better agreement with experimental observations than ZRM, especially when high- and low-LET radiations are mixed. In these situations, the ZRM overestimated the surviving fraction. Furthermore, the EQDX calculated with mZRM are in better agreement with experimental observations. CONCLUSION The mZRM is a computationally efficient model that can be used to predict biological response to mixed radiations that have low- and high-LET characteristics. Importantly, interaction terms are retained in the calculation of EQDX for mixed radiation exposures within the mZRM framework. The mZRM has application in a wide range of radiation therapies, including radiopharmaceutical therapy.
Collapse
Affiliation(s)
- Sumudu Katugampola
- Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Robert F Hobbs
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Roger W Howell
- Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| |
Collapse
|
2
|
Chan CY, Chen Z, Guibbal F, Dias G, Destro G, O'Neill E, Veal M, Lau D, Mosley M, Wilson TC, Gouverneur V, Cornelissen B. [ 123I]CC1: A PARP-Targeting, Auger Electron-Emitting Radiopharmaceutical for Radionuclide Therapy of Cancer. J Nucl Med 2023; 64:1965-1971. [PMID: 37770109 PMCID: PMC10690119 DOI: 10.2967/jnumed.123.265429] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 05/24/2023] [Indexed: 10/03/2023] Open
Abstract
Poly(adenosine diphosphate ribose) polymerase (PARP) has emerged as an effective therapeutic strategy against cancer that targets the DNA damage repair enzyme. PARP-targeting compounds radiolabeled with an Auger electron-emitting radionuclide can be trapped close to damaged DNA in tumor tissue, where high ionizing potential and short range lead Auger electrons to kill cancer cells through the creation of complex DNA damage, with minimal damage to surrounding normal tissue. Here, we report on [123I]CC1, an 123I-labeled PARP inhibitor for radioligand therapy of cancer. Methods: Copper-mediated 123I iododeboronation of a boronic pinacol ester precursor afforded [123I]CC1. The level and specificity of cell uptake and the therapeutic efficacy of [123I]CC1 were determined in human breast carcinoma, pancreatic adenocarcinoma, and glioblastoma cells. Tumor uptake and tumor growth inhibition of [123I]CC1 were assessed in mice bearing human cancer xenografts (MDA-MB-231, PSN1, and U87MG). Results: In vitro and in vivo studies showed selective uptake of [123I]CC1 in all models. Significantly reduced clonogenicity, a proxy for tumor growth inhibition by ionizing radiation in vivo, was observed in vitro after treatment with as little as 10 Bq [123I]CC1. Biodistribution at 1 h after intravenous administration showed PSN1 tumor xenograft uptake of 0.9 ± 0.06 percentage injected dose per gram of tissue. Intravenous administration of a relatively low amount of [123I]CC1 (3 MBq) was able to significantly inhibit PSN1 xenograft tumor growth but was less effective in xenografts that expressed less PARP. [123I]CC1 did not cause significant toxicity to normal tissues. Conclusion: Taken together, these results show the potential of [123I]CC1 as a radioligand therapy for PARP-expressing cancers.
Collapse
Affiliation(s)
- Chung Ying Chan
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Zijun Chen
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom; and
| | - Florian Guibbal
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Gemma Dias
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Gianluca Destro
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom; and
| | - Edward O'Neill
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Mathew Veal
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Doreen Lau
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Michael Mosley
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Thomas C Wilson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom; and
| | - Véronique Gouverneur
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom; and
| | - Bart Cornelissen
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom;
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
3
|
Garcia-Prada CD, Carmes L, Atis S, Parach A, Bertolet A, Jarlier M, Poty S, Garcia DS, Shin WG, Du Manoir S, Schuemann J, Tillement O, Lux F, Constanzo J, Pouget JP. Gadolinium-Based Nanoparticles Sensitize Ovarian Peritoneal Carcinomatosis to Targeted Radionuclide Therapy. J Nucl Med 2023; 64:1956-1964. [PMID: 37857502 PMCID: PMC10690115 DOI: 10.2967/jnumed.123.265418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 08/28/2023] [Indexed: 10/21/2023] Open
Abstract
Ovarian cancer (OC) is the most lethal gynecologic malignancy (5-y overall survival rate, 46%). OC is generally detected when it has already spread to the peritoneal cavity (peritoneal carcinomatosis). This study investigated whether gadolinium-based nanoparticles (Gd-NPs) increase the efficacy of targeted radionuclide therapy using [177Lu]Lu-DOTA-trastuzumab (an antibody against human epidermal growth factor receptor 2). Gd-NPs have radiosensitizing effects in conventional external-beam radiotherapy and have been tested in clinical phase II trials. Methods: First, the optimal activity of [177Lu]Lu-DOTA-trastuzumab (10, 5, or 2.5 MBq) combined or not with 10 mg of Gd-NPs (single injection) was investigated in athymic mice bearing intraperitoneal OC cell (human epidermal growth factor receptor 2-positive) tumor xenografts. Next, the therapeutic efficacy and toxicity of 5 MBq of [177Lu]Lu-DOTA-trastuzumab with Gd-NPs (3 administration regimens) were evaluated. NaCl, trastuzumab plus Gd-NPs, and [177Lu]Lu-DOTA-trastuzumab alone were used as controls. Biodistribution and dosimetry were determined, and Monte Carlo simulation of energy deposits was performed. Lastly, Gd-NPs' subcellular localization and uptake, and the cytotoxic effects of the combination, were investigated in 3 cancer cell lines to obtain insights into the involved mechanisms. Results: The optimal [177Lu]Lu-DOTA-trastuzumab activity when combined with Gd-NPs was 5 MBq. Moreover, compared with [177Lu]Lu-DOTA-trastuzumab alone, the strongest therapeutic efficacy (tumor mass reduction) was obtained with 2 injections of 5 mg of Gd-NPs/d (separated by 6 h) at 24 and 72 h after injection of 5 MBq of [177Lu]Lu-DOTA-trastuzumab. In vitro experiments showed that Gd-NPs colocalized with lysosomes and that their radiosensitizing effect was mediated by oxidative stress and inhibited by deferiprone, an iron chelator. Exposure of Gd-NPs to 177Lu increased the Auger electron yield but not the absorbed dose. Conclusion: Targeted radionuclide therapy can be combined with Gd-NPs to increase the therapeutic effect and reduce the injected activities. As Gd-NPs are already used in the clinic, this combination could be a new therapeutic approach for patients with ovarian peritoneal carcinomatosis.
Collapse
Affiliation(s)
- Clara Diaz Garcia-Prada
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Léna Carmes
- Institut Lumière Matière, Université Claude Bernard Lyon 1, Villeurbanne, France
- NH TherAguix S.A., Meylan, France
| | - Salima Atis
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Ali Parach
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Alejandro Bertolet
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Marta Jarlier
- Biometrics Unit, Montpellier Cancer Institute, University of Montpellier, Montpellier, France; and
| | - Sophie Poty
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Daniel Suarez Garcia
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Wook-Geun Shin
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Stanislas Du Manoir
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Olivier Tillement
- Institut Lumière Matière, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - François Lux
- Institut Lumière Matière, Université Claude Bernard Lyon 1, Villeurbanne, France
- Institut Universitaire de France, Paris, France
| | - Julie Constanzo
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France;
| | - Jean-Pierre Pouget
- Institut de Recherche en Cancérologie de Montpellier, Inserm U1194, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France;
| |
Collapse
|
4
|
Larouze A, Alcocer-Ávila M, Morgat C, Champion C, Hindié E. Membrane and Nuclear Absorbed Doses from 177Lu and 161Tb in Tumor Clusters: Effect of Cellular Heterogeneity and Potential Benefit of Dual Targeting-A Monte Carlo Study. J Nucl Med 2023; 64:1619-1624. [PMID: 37321819 DOI: 10.2967/jnumed.123.265509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 05/11/2023] [Indexed: 06/17/2023] Open
Abstract
Early use of targeted radionuclide therapy to eradicate tumor cell clusters and micrometastases might offer cure. However, there is a need to select appropriate radionuclides and assess the potential impact of heterogeneous targeting. Methods: The Monte Carlo code CELLDOSE was used to assess membrane and nuclear absorbed doses from 177Lu and 161Tb (β--emitter with additional conversion and Auger electrons) in a cluster of 19 cells (14-μm diameter, 10-μm nucleus). The radionuclide distributions considered were cell surface, intracytoplasmic, or intranuclear, with 1,436 MeV released per labeled cell. To model heterogeneous targeting, 4 of the 19 cells were unlabeled, their position being stochastically determined. We simulated situations of single targeting, as well as dual targeting, with the 2 radiopharmaceuticals aiming at different targets. Results: 161Tb delivered 2- to 6-fold higher absorbed doses to cell membranes and 2- to 3-fold higher nuclear doses than 177Lu. When all 19 cells were targeted, membrane and nuclear absorbed doses were dependent mainly on radionuclide location. With cell surface location, membrane absorbed doses were substantially higher than nuclear absorbed doses, both with 177Lu (38-41 vs. 4.7-7.2 Gy) and with 161Tb (237-244 vs. 9.8-15.1 Gy). However, when 4 cells were not targeted by the cell surface radiopharmaceutical, the membranes of these cells received on average only 9.6% of the 177Lu absorbed dose and 2.9% of the 161Tb dose, compared with a cluster with uniform cell targeting, whereas the impact on nuclear absorbed doses was moderate. With an intranuclear radionuclide location, the nuclei of unlabeled cells received only 17% of the 177Lu absorbed dose and 10.8% of the 161Tb dose, compared with situations with uniform targeting. With an intracytoplasmic location, nuclear and membrane absorbed doses to unlabeled cells were one half to one quarter those obtained with uniform targeting, both for 177Lu and for 161Tb. Dual targeting was beneficial in minimizing absorbed dose heterogeneities. Conclusion: To eradicate tumor cell clusters, 161Tb may be a better candidate than 177Lu. Heterogeneous cell targeting can lead to substantial heterogeneities in absorbed doses. Dual targeting was helpful in reducing dose heterogeneity and should be explored in preclinical and clinical studies.
Collapse
Affiliation(s)
- Alexandre Larouze
- Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, Talence, France
| | - Mario Alcocer-Ávila
- Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, Talence, France
| | - Clément Morgat
- Service de Médecine Nucléaire, CHU de Bordeaux, Université de Bordeaux, UMR CNRS 5287, INCIA, Talence, France; and
| | - Christophe Champion
- Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, Talence, France;
| | - Elif Hindié
- Service de Médecine Nucléaire, CHU de Bordeaux, Université de Bordeaux, UMR CNRS 5287, INCIA, Talence, France; and
- Institut Universitaire de France, Paris, France
| |
Collapse
|
5
|
Rumiantcev M, Li WB, Lindner S, Liubchenko G, Resch S, Bartenstein P, Ziegler SI, Böning G, Delker A. Estimation of relative biological effectiveness of 225Ac compared to 177Lu during [ 225Ac]Ac-PSMA and [ 177Lu]Lu-PSMA radiopharmaceutical therapy using TOPAS/TOPAS-nBio/MEDRAS. EJNMMI Phys 2023; 10:53. [PMID: 37695374 PMCID: PMC10495309 DOI: 10.1186/s40658-023-00567-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 08/07/2023] [Indexed: 09/12/2023] Open
Abstract
AIM Over recent years, [225Ac]Ac-PSMA and [177Lu]Lu-PSMA radiopharmaceutical therapy have evolved as a promising treatment option for advanced prostate cancer. Especially for alpha particle emitter treatments, there is still a need for improving dosimetry, which requires accurate values of relative biological effectiveness (RBE). To achieve that, consideration of DNA damages in the cell nucleus and knowledge of the energy deposition in the location of the DNA at the nanometer scale are required. Monte Carlo particle track structure simulations provide access to interactions at this level. The aim of this study was to estimate the RBE of 225Ac compared to 177Lu. The initial damage distribution after radionuclide decay and the residual damage after DNA repair were considered. METHODS This study employed the TOol for PArtcile Simulation (TOPAS) based on the Geant4 simulation toolkit. Simulation of the nuclear DNA and damage scoring were performed using the TOPAS-nBio extension of TOPAS. DNA repair was modeled utilizing the Python-based program MEDRAS (Mechanistic DNA Repair and Survival). Five different cell geometries of equal volume and two radionuclide internalization assumptions as well as two cell arrangement scenarios were investigated. The radionuclide activity (number of source points) was adopted based on SPECT images of patients undergoing the above-mentioned therapies. RESULTS Based on the simulated dose-effect curves, the RBE of 225Ac compared to 177Lu was determined in a wide range of absorbed doses to the nucleus. In the case of spherical geometry, 3D cell arrangement and full radionuclide internalization, the RBE based on the initial damage had a constant value of approximately 2.14. Accounting for damage repair resulted in RBE values ranging between 9.38 and 1.46 for 225Ac absorbed doses to the nucleus between 0 and 50 Gy, respectively. CONCLUSION In this work, the consideration of DNA repair of the damage from [225Ac]Ac-PSMA and [177Lu]Lu-PSMA revealed a dose dependency of the RBE. Hence, this work suggested that DNA repair is an important aspect to understand response to different radiation qualities.
Collapse
Affiliation(s)
- Mikhail Rumiantcev
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany.
| | - Wei Bo Li
- Federal Office for Radiation Protection, Medical and Occupational Radiation Protection, Oberschleißheim, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Grigory Liubchenko
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Sandra Resch
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Sibylle I Ziegler
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Guido Böning
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Astrid Delker
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| |
Collapse
|
6
|
Chung SK, Vargas DB, Chandler CS, Katugampola S, Veach DR, McDevitt MR, Seo SH, Vaughn BA, Rinne SS, Punzalan B, Patel M, Xu H, Guo HF, Zanzonico PB, Monette S, Yang G, Ouerfelli O, Nash GM, Cercek A, Fung EK, Howell RW, Larson SM, Cheal SM, Cheung NKV. Efficacy of HER2-Targeted Intraperitoneal 225Ac α-Pretargeted Radioimmunotherapy for Small-Volume Ovarian Peritoneal Carcinomatosis. J Nucl Med 2023; 64:1439-1445. [PMID: 37348919 PMCID: PMC10478816 DOI: 10.2967/jnumed.122.265095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 04/14/2023] [Indexed: 06/24/2023] Open
Abstract
Epithelial ovarian cancer (EOC) is often asymptomatic and presents clinically in an advanced stage as widespread peritoneal microscopic disease that is generally considered to be surgically incurable. Targeted α-therapy with the α-particle-emitting radionuclide 225Ac (half-life, 9.92 d) is a high-linear-energy-transfer treatment approach effective for small-volume disease and even single cells. Here, we report the use of human epidermal growth factor receptor 2 (HER2) 225Ac-pretargeted radioimmunotherapy (PRIT) to treat a mouse model of human EOC SKOV3 xenografts growing as peritoneal carcinomatosis (PC). Methods: On day 0, 105 SKOV3 cells transduced with a luciferase reporter gene were implanted intraperitoneally in nude mice, and tumor engraftment was verified by bioluminescent imaging (BLI). On day 15, treatment was started using 1 or 2 cycles of 3-step anti-HER2 225Ac-PRIT (37 kBq/cycle as 225Ac-Proteus DOTA), separated by a 1-wk interval. Efficacy and toxicity were monitored for up to 154 d. Results: Untreated PC-tumor-bearing nude mice showed a median survival of 112 d. We used 2 independent measures of response to evaluate the efficacy of 225Ac-PRIT. First, a greater proportion of the treated mice (9/10 1-cycle and 8/10 2-cycle; total, 17/20; 85%) survived long-term compared with controls (9/27, 33%), and significantly prolonged survival was documented (log-rank [Mantel-Cox] P = 0.0042). Second, using BLI, a significant difference in the integrated BLI signal area to 98 d was noted between controls and treated groups (P = 0.0354). Of a total of 8 mice from the 2-cycle treatment group (74 kBq total) that were evaluated by necropsy, kidney radiotoxicity was mild and did not manifest itself clinically (normal serum blood urea nitrogen and creatinine). Dosimetry estimates (relative biological effectiveness-weighted dose, where relative biological effectiveness = 5) per 37 kBq administered for tumors and kidneys were 56.9 and 16.1 Gy, respectively. One-cycle and 2-cycle treatments were equally effective. With immunohistology, mild tubular changes attributable to α-toxicity were observed in both therapeutic groups. Conclusion: Treatment of EOC PC-tumor-bearing mice with anti-HER2 225Ac-PRIT resulted in histologic cures and prolonged survival with minimal toxicity. Targeted α-therapy using the anti-HER2 225Ac-PRIT system is a potential treatment for otherwise incurable EOC.
Collapse
Affiliation(s)
- Sebastian K Chung
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | | | | | - Sumudu Katugampola
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Darren R Veach
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Michael R McDevitt
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Shin H Seo
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Brett A Vaughn
- Department of Radiology, Weill Cornell Medicine, New York, New York
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sara S Rinne
- Department of Radiology, Weill Cornell Medicine, New York, New York
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Blesida Punzalan
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Mitesh Patel
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Hong Xu
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Hong-Fen Guo
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Pat B Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sébastien Monette
- Laboratory of Comparative Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and Rockefeller University, New York, New York; and
| | - Guangbin Yang
- Organic Synthesis Core Facility, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ouathek Ouerfelli
- Organic Synthesis Core Facility, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Garrett M Nash
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Andrea Cercek
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Edward K Fung
- Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Roger W Howell
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Steven M Larson
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Weill Cornell Medicine, New York, New York
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sarah M Cheal
- Department of Radiology, Weill Cornell Medicine, New York, New York;
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
| |
Collapse
|
7
|
Bolcaen J, Gizawy MA, Terry SYA, Paulo A, Cornelissen B, Korde A, Engle J, Radchenko V, Howell RW. Marshalling the Potential of Auger Electron Radiopharmaceutical Therapy. J Nucl Med 2023; 64:1344-1351. [PMID: 37591544 PMCID: PMC10478825 DOI: 10.2967/jnumed.122.265039] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 07/05/2023] [Indexed: 08/19/2023] Open
Abstract
Auger electron (AE) radiopharmaceutical therapy (RPT) may have the same therapeutic efficacy as α-particles for oncologic small disease, with lower risks of normal-tissue toxicity. The seeds of using AE emitters for RPT were planted several decades ago. Much knowledge has been gathered about the potency of the biologic effects caused by the intense shower of these low-energy AEs. Given their short range, AEs deposit much of their energy in the immediate vicinity of their site of decay. However, the promise of AE RPT has not yet been realized, with few agents evaluated in clinical trials and none becoming part of routine treatment so far. Instigated by the 2022 "Technical Meeting on Auger Electron Emitters for Radiopharmaceutical Developments" at the International Atomic Energy Agency, this review presents the current status of AE RPT based on the discussions by experts in the field. A scoring system was applied to illustrate hurdles in the development of AE RPT, and we present a selected list of well-studied and emerging AE-emitting radionuclides. Based on the number of AEs and other emissions, physical half-life, radionuclide production, radiochemical approaches, dosimetry, and vector availability, recommendations are put forward to enhance and impact future efforts in AE RPT research.
Collapse
Affiliation(s)
- Julie Bolcaen
- SSC Laboratory, Radiation Biophysics, NRF iThemba LABS, Cape Town, South Africa
| | - Mohamed A Gizawy
- Egyptian Second Research Reactor Complex, Egyptian Atomic Energy Authority, Cairo, Egypt
| | - Samantha Y A Terry
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - António Paulo
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Campus Tecnológico e Nuclear, Bobadela, Portugal
| | - Bart Cornelissen
- Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Aruna Korde
- Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Application, International Atomic Energy Agency, Vienna, Austria
| | - Jonathan Engle
- University of Wisconsin Cyclotron Research Group, Departments of Medical Physics and Radiology, Madison, Wisconsin
| | - Valery Radchenko
- TRIUMF, Life Sciences Division, Vancouver, British Columbia, Canada;
- University of British Columbia, Chemistry Department, Vancouver, British Columbia, Canada; and
| | - Roger W Howell
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, Newark, New Jersey
| |
Collapse
|
8
|
Koniar H, Miller C, Rahmim A, Schaffer P, Uribe C. A GATE simulation study for dosimetry in cancer cell and micrometastasis from the 225Ac decay chain. EJNMMI Phys 2023; 10:46. [PMID: 37525027 PMCID: PMC10390455 DOI: 10.1186/s40658-023-00564-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 07/24/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND Radiopharmaceutical therapy (RPT) with alpha-emitting radionuclides has shown great promise in treating metastatic cancers. The successive emission of four alpha particles in the 225Ac decay chain leads to highly targeted and effective cancer cell death. Quantifying cellular dosimetry for 225Ac RPT is essential for predicting cell survival and therapeutic success. However, the leading assumption that all 225Ac progeny remain localized at their target sites likely overestimates the absorbed dose to cancer cells. To address limitations in existing semi-analytic approaches, this work evaluates S-values for 225Ac's progeny radionuclides with GATE Monte Carlo simulations. METHODS The cellular geometries considered were an individual cell (10 µm diameter with a nucleus of 8 µm diameter) and a cluster of cells (micrometastasis) with radionuclides localized in four subcellular regions: cell membrane, cytoplasm, nucleus, or whole cell. The absorbed dose to the cell nucleus was scored, and self- and cross-dose S-values were derived. We also evaluated the total absorbed dose with various degrees of radiopharmaceutical internalization and retention of the progeny radionuclides 221Fr (t1/2 = 4.80 m) and 213Bi (t1/2 = 45.6 m). RESULTS For the cumulative 225Ac decay chain, our self- and cross-dose nuclear S-values were both in good agreement with S-values published by MIRDcell, with per cent differences ranging from - 2.7 to - 8.7% for the various radionuclide source locations. Source location had greater effects on self-dose S-values than the intercellular cross-dose S-values. Cumulative 225Ac decay chain self-dose S-values increased from 0.167 to 0.364 GyBq-1 s-1 with radionuclide internalization from the cell surface into the cell. When progeny migration from the target site was modelled, the cumulative self-dose S-values to the cell nucleus decreased by up to 71% and 21% for 221Fr and 213Bi retention, respectively. CONCLUSIONS Our GATE Monte Carlo simulations resulted in cellular S-values in agreement with existing MIRD S-values for the alpha-emitting radionuclides in the 225Ac decay chain. To obtain accurate absorbed dose estimates in 225Ac studies, accurate understanding of daughter migration is critical for optimized injected activities. Future work will investigate other novel preclinical alpha-emitting radionuclides to evaluate therapeutic potency and explore realistic cellular geometries corresponding to targeted cancer cell lines.
Collapse
Affiliation(s)
- Helena Koniar
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.
| | - Cassandra Miller
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
| | - Arman Rahmim
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Carlos Uribe
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Functional Imaging, BC Cancer, Vancouver, BC, Canada
| |
Collapse
|
9
|
Kesner AL, Carter LM, Ramos JCO, Lafontaine D, Olguin EA, Brown JL, President B, Jokisch DW, Fisher DR, Bolch WE. MIRD Pamphlet No. 28, Part 1: MIRDcalc-A Software Tool for Medical Internal Radiation Dosimetry. J Nucl Med 2023; 64:1117-1124. [PMID: 37268428 PMCID: PMC10315701 DOI: 10.2967/jnumed.122.264225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 03/21/2023] [Indexed: 06/04/2023] Open
Abstract
Medical internal radiation dosimetry constitutes a fundamental aspect of diagnosis, treatment, optimization, and safety in nuclear medicine. The MIRD committee of the Society of Nuclear Medicine and Medical Imaging developed a new computational tool to support organ-level and suborgan tissue dosimetry (MIRDcalc, version 1). Based on a standard Excel spreadsheet platform, MIRDcalc provides enhanced capabilities to facilitate radiopharmaceutical internal dosimetry. This new computational tool implements the well-established MIRD schema for internal dosimetry. The spreadsheet incorporates a significantly enhanced database comprising details for 333 radionuclides, 12 phantom reference models (International Commission on Radiological Protection), 81 source regions, and 48 target regions, along with the ability to interpolate between models for patient-specific dosimetry. The software also includes sphere models of various composition for tumor dosimetry. MIRDcalc offers several noteworthy features for organ-level dosimetry, including modeling of blood source regions and dynamic source regions defined by user input, integration of tumor tissues, error propagation, quality control checks, batch processing, and report-preparation capabilities. MIRDcalc implements an immediate, easy-to-use single-screen interface. The MIRDcalc software is available for free download (www.mirdsoft.org) and has been approved by the Society of Nuclear Medicine and Molecular Imaging.
Collapse
Affiliation(s)
- Adam L Kesner
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York;
| | - Lukas M Carter
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Juan C Ocampo Ramos
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Daniel Lafontaine
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Edmond A Olguin
- Beth Israel Deaconess Medical Center, Department of Radiology, Harvard Medical School, Boston, Massachusetts
| | - Justin L Brown
- J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Bonnie President
- J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Derek W Jokisch
- Department of Physics and Engineering, Francis Marion University, Florence, South Carolina
- Center for Radiation Protection Knowledge, Oak Ridge National Laboratory, Oak Ridge, Tennessee; and
| | - Darrell R Fisher
- University of Washington and Versant Medical Physics and Radiation Safety, Richland, Washington
| | - Wesley E Bolch
- J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| |
Collapse
|
10
|
Fung EK, Zanzonico PB. Monitoring the biodistribution of radiolabeled therapeutics in mice. Methods Cell Biol 2023; 180:93-111. [PMID: 37890935 DOI: 10.1016/bs.mcb.2023.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2023]
Abstract
Radiopharmaceutical therapy is a rapidly growing field for the treatment of cancer due to its high specificity and ability to target individual affected cells. A key component of the pre-clinical development of a new therapeutic radiopharmaceutical is the determination of its time-dependent distribution in tumors, normal tissues, and the whole body in mouse tumor models. Here, we provide an overview of the available instrumentation for the novice in radiation measurement. We also detail the methodology for assessing distribution and kinetics of a radiopharmaceutical and calculating radiation absorbed dose in mice using a gamma counter or a PET or SPECT camera.
Collapse
Affiliation(s)
- Edward K Fung
- Department of Radiology, Weill Cornell Medicine, New York, NY, United States.
| | - Pat B Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Medical Center, New York, NY, United States
| |
Collapse
|
11
|
Lin W, Aluicio-Sarduy E, Houson HA, Barnhart TE, Tekin V, Jeffery JJ, Weichmann AM, Barrett KE, Lapi SE, Engle JW. Theranostic cobalt-55/58m for neurotensin receptor-mediated radiotherapy in vivo: A pilot study with dosimetry. Nucl Med Biol 2023; 118-119:108329. [PMID: 36805869 PMCID: PMC10121947 DOI: 10.1016/j.nucmedbio.2023.108329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 02/17/2023]
Abstract
Neurotensin receptor 1 (NTSR1) can stimulate tumor proliferation through neurotensin (NTS) activation and are overexpressed by a variety of cancers. The high binding affinity of NTS/NTSR1 makes radiolabeled NTS derivatives interesting for cancer diagnosis and staging. Internalization of NTS/NTSR1 also suggests therapeutic application with high LET alpha particles and low energy electrons. We investigated the therapeutic efficacy of [58mCo]Co-NOTA-NT-20.3 in vivo using murine models xenografted with NTSR1-positive HT29 human colorectal adenocarcinoma cells, and utilized [55Co]Co-NOTA-NT-20.3 for dosimetry. METHODS Targeting properties and cytotoxicity of [55/58mCo]Co-NOTA-NT-20.3 were assessed with HT29 cells. Female nude mice were xenografted with HT29 tumors and administered [55Co or 58mCo]Co-NOTA-NT-20.3 to evaluate pharmacokinetics or for therapy, respectively. Dosimetry calculations followed the Medical Internal Radiation Dose (MIRD) formalism and human absorbed dose rate per unit activity were obtained from OpenDose. The pilot therapy study consisted of two groups (each N = 3) receiving 110 ± 15 MBq and 26 ± 6 MBq [58mCo]Co-NOTA-NT-20.3 one week after tumor inoculation, and control (N = 3). Tumor sizes and masses were measured twice a week after therapy. Complete blood count and kidney histology were also performed to assess toxicity. RESULTS HPLC measured radiochemical purity of [55,58mCo]Co-NOTA-NT-20.3 > 99 %. Labeled compounds retained NTS targeting properties. [58mCo]Co-NOTA-NT-20.3 exhibited cytotoxicity for HT29 cells and was >15× more potent than [58mCo]CoCl2. Xenografted tumors responded modestly to administered doses, but mice showed no signs of radiotoxicity. Absorbed dose to tumor and kidney with 110 MBq [58mCo]Co-NOTA-NT-20.3 were 0.6 Gy and 0.8 Gy, respectively, and other organs received less than half of the absorbed dose to tumor. Off-target radiation dose from cobalt-58g was small but reduces the therapeutic window. CONCLUSION The enhanced in vitro cytotoxicity and high tumor-to-background led us to investigate the therapeutic efficacy of [58mCo]Co-NOTA-NT-20.3 in vivo. Although we were unable to induce tumor response commensurate with [177Lu]Lu-NT127 (NLys-Lys-Pro-Tyr-Tle-Leu) studies involving similar time-integrated activity, the absence of observed toxicity may constitute an opportunity for targeting vectors with improved uptake and/or retention to avoid the aftereffects of other high-LET radioactive emissions. Future studies with higher uptake, activity and/or multiple dosing regimens are warranted. The theranostic approach employed in this work was crucial for dosimetry analysis.
Collapse
Affiliation(s)
- Wilson Lin
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States.
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States
| | - Hailey A Houson
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, United States
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States
| | - Volkan Tekin
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, United States
| | - Justin J Jeffery
- University of Wisconsin Carbone Cancer Center, Madison, WI 53705, United States
| | - Ashley M Weichmann
- University of Wisconsin Carbone Cancer Center, Madison, WI 53705, United States
| | - Kendall E Barrett
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States
| | - Suzanne E Lapi
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, United States
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin, 1111 Highland Ave., Madison, WI 53705, United States; Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53792, United States
| |
Collapse
|
12
|
Katugampola S, Wang J, Prasad A, Sofou S, Howell RW. Predicting response of micrometastases with MIRDcell V3: proof of principle with 225Ac-DOTA encapsulating liposomes that produce different activity distributions in tumor spheroids. Eur J Nucl Med Mol Imaging 2022; 49:3989-3999. [PMID: 35802160 PMCID: PMC9529908 DOI: 10.1007/s00259-022-05878-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 06/14/2022] [Indexed: 11/04/2022]
Abstract
PURPOSE The spatial distribution of radiopharmaceuticals within multicellular clusters is known to have a significant effect on their biological response. Most therapeutic radiopharmaceuticals distribute nonuniformly in tissues which makes predicting responses of micrometastases challenging. The work presented here analyzes published temporally dependent nonuniform activity distributions within tumor spheroids treated with actinium-225-DOTA encapsulating liposomes (225Ac-liposomes) and uses these data in MIRDcell V3.11 to calculate absorbed dose distributions and predict biological response. The predicted responses are compared with experimental responses. METHODS Four types of liposomes were prepared having membranes with different combinations of release (R) and adhesion (A) properties. The combinations were R-A-, R-A+, R+A-, and R+A+. These afford different penetrating properties into tissue. The liposomes were loaded with either carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) or 225Ac. MDA-MB-231 spheroids were treated with the CFDA-SE-liposomes, harvested at different times, and the time-integrated CFDA-SE concentration at each radial position within the spheroid was determined. This was translated into mean 225Ac decays/cell versus radial position, uploaded to MIRDcell, and the surviving fraction of cells in spherical multicellular clusters was simulated. The MIRDcell-predicted surviving fractions were compared with experimental fractional-outgrowths of the spheroids following treatment with 225Ac-liposomes. RESULTS The biological responses of the multicellular clusters treated with 225Ac-liposomes with physicochemical properties R+A+, R-A+, and R-A- were predicted by MIRDcell with statistically significant accuracy. The prediction for R+A- was not predicted accurately. CONCLUSION In most instances, MIRDcell predicts responses of spheroids treated with 225Ac-liposomes that result in different tissue-penetrating profiles of the delivered radionuclides.
Collapse
Affiliation(s)
- Sumudu Katugampola
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ, 07103, USA
| | - Jianchao Wang
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ, 07103, USA
| | - Aprameya Prasad
- Department of Chemical and Biomolecular Engineering, Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Stavroula Sofou
- Department of Chemical and Biomolecular Engineering, Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Roger W Howell
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ, 07103, USA.
| |
Collapse
|
13
|
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:pharmaceutics14102007. [PMID: 36297446 PMCID: PMC9608466 DOI: 10.3390/pharmaceutics14102007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [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
- Correspondence:
| | - 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
|