| 1. |
- Abou, Diane S., et al.
(författare)
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Improved 223Ra Therapy with Combination Epithelial Sodium Channel Blockade
- 2021
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 62:12, s. 1751-1758
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Tidskriftsartikel (refereegranskat)abstract
- [223Ra]RaCl2 is the first approved a-particle-emitting therapy and is indicated for treatment of bonemetastatic castration-resistant prostate cancer. Approximately half the dose is absorbed into the gastrointestinal tract within minutes of administration, limiting disease-site uptake and contributing to toxicity. Here,we investigated the role of enteric ion channels and their modulation for improved therapeutic efficacy and reduced side effects. Methods: Using primary human duodenal organoids (enteroids) asin vitromodelsof the functionalgastrointestinal epithelium, we found that amiloride (epithelial sodium ion channel blocker) and NS-1619 (K+ channel activator) presented significant effects in 223Ramembranal transport.Radioactivedrugdistributionwas evaluated for lead combinations in vivo and in osteosarcoma and prostate cancermodels.Results:Amiloride shifted 223Ra uptake in vivo fromthe gut and nearly doubled the uptake at sites of bone remodeling. Bone tumor growth inhibition with the combination as measured by bioluminescent imaging and radiographywas significantly greater than that with single agents alone, and the combination resulted in noweight loss.Conclusion: This combination of approved agentsmay readily be implemented as a clinical approach to improve the outcomes of bonemetastatic cancer patients with the benefit of ameliorated tolerability. COPYRIGHT
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| 2. |
- Benabdallah, Nadia, et al.
(författare)
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Beyond Average : a-Particle Distribution and Dose Heterogeneity in Bone Metastatic Prostate Cancer
- 2024
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 65:2, s. 245-251
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Tidskriftsartikel (refereegranskat)abstract
- a-particle emitters are emerging as a potent modality for disseminated cancer therapy because of their high linear energy transfer and localized absorbed dose profile. Despite great interest and pharmaceutical development, there is scant information on the distribution of these agents at the scale of the a-particle pathlength. We sought to determine the distribution of clinically approved [223Ra]RaCl2 in bone metastatic castration-resistant prostate cancer at this resolution, for the first time to our knowledge, to inform activity distribution and dose at the near-cell scale. Methods: Biopsy specimens and blood were collected from 7 patients 24 h after administration. 223Ra activity in each sample was recorded, and the microstructure of biopsy specimens was analyzed by micro-CT. Quantitative autoradiography and histopathology were segmented and registered with an automated procedure. Activity distributions by tissue compartment and dosimetry calculations based on the MIRD formalism were performed. Results: We revealed the activity distribution differences across and within patient samples at the macro- and microscopic scales. Microdistribution analysis confirmed localized high-activity regions in a background of low-activity tissue. We evaluated heterogeneous a-particle emission distribution concentrated at bone–tissue interfaces and calculated spatially nonuniform absorbed-dose profiles. Conclusion: Primary patient data of radiopharmaceutical therapy distribution at the small scale revealed that 223Ra uptake is nonuniform. Dose estimates present both opportunities and challenges to enhance patient outcomes and are a first step toward personalized treatment approaches and improved understanding of a-particle radiopharmaceutical therapies.
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| 3. |
- Vogelzang, Nicholas J., et al.
(författare)
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Hematologic Safety of Radium-223 Dichloride : Baseline Prognostic Factors Associated With Myelosuppression in the ALSYMPCA Trial
- 2017
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Ingår i: Clinical Genitourinary Cancer. - : CIG MEDIA GROUP, LP. - 1558-7673 .- 1938-0682. ; 15:1, s. 42-52
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Tidskriftsartikel (refereegranskat)abstract
- Radium-223 was minimally myelosuppressive. Multivariate analyses of data from ALSYMPCA patients identified baseline factors that may increase hematologic toxicity risk with radium-223. Extent of disease and degree of prostate-specific antigen elevation were predictive of grade 2-4 anemia; prior docetaxel, and decreased hemoglobin and platelets were predictive of grade 2-4 thrombocytopenia. Patients with these factors should be closely monitored during radium-223 therapy. Background: Myelosuppression is common in patients with progressive castration-resistant prostate cancer and bone metastases. Radium-223 prolongs overall survival in these patients but may cause myelosuppression; understanding risk factors will improve clinical decision making. We describe hematologic safety of radium-223 in ALSYMPCA and post hoc analyses identifying patients at increased risk for hematologic toxicity. Patients and Methods: Hematologic parameters and adverse events were analyzed. Multivariate analyses assessing baseline risk factors for hematologic toxicities were performed separately for radium-223 and placebo patients. Results: Nine hundred one patients received radium-223 (n = 600) or placebo (n = 301); 65% of radium-223 and 48% of placebo patients had the full 6 cycles. Grade 3/4 thrombocytopenia was more common in radium-223 versus placebo patients (6% vs. 2%). Logistic regression analyses identified significant baseline predictors for grade 2-4 hematologic toxicities related to radium-223 treatment: extent of disease (6-20 vs. < 6 bone metastases; odds ratio [OR] = 2.76; P = .022) and elevated prostate-specific antigen (OR = 1.65; P = .006) for anemia; prior docetaxel (OR = 2.16; P = .035), decreased hemoglobin (OR = 1.35; P = .008), and decreased platelets (OR = 1.44; P = .030) for thrombocytopenia. Neutropenia events were too few in placebo patients for a comparative analysis. There were no significant associations between hematologic toxicities and number of radium-223 injections received (4-6 vs. 1-3). Conclusion: Radium-223 has a favorable safety profile with a low myelosuppression incidence. Understanding baseline factors associated with myelosuppression may assist clinicians in avoiding severe myelosuppression events with radium-223.
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