The treatment of solid tumors by alpha emitters released from (224)Ra-loaded sources-internal dosimetry analysis.
Phys Med Biol
; 55(4): 1203-18, 2010 Feb 21.
Article
en En
| MEDLINE
| ID: mdl-20124656
ABSTRACT
Diffusing alpha-emitters radiation therapy (DART) is a proposed new form of brachytherapy, allowing the treatment of solid tumors by alpha particles. DART utilizes implantable sources carrying small activities of radium-224, which continually release into the tumor radon-220, polonium-216 and lead-212 atoms, while radium-224 itself remains fixed to the source. The released atoms disperse inside the tumor by diffusive and convective processes, creating, through their alpha emissions, a high-dose region measuring several mm in diameter about each source. The efficacy of DART has been demonstrated in preclinical studies on mice-borne squamous cell carcinoma and lung tumors and the method is now being developed toward clinical trials. This work studies DART safety with respect to the dose delivered to distant organs as a result of lead-212 leakage from the tumor through the blood, relying on a biokinetic calculation coupled to internal dose assessments. It is found that the dose-limiting organs are the kidneys and red bone marrow. Assuming a typical source spacing of approximately 5 mm and a typical radium-224 activity density of 0.4-0.8 MBq g(-1) of tumor tissue, it is predicted that tumors weighing up to several hundred grams may be treated without reaching the tolerance dose in any organ.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Radioisótopos
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Braquiterapia
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Radio (Elemento)
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Partículas alfa
Tipo de estudio:
Prognostic_studies
Límite:
Animals
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Female
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Humans
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Male
Idioma:
En
Revista:
Phys Med Biol
Año:
2010
Tipo del documento:
Article
País de afiliación:
Israel