Relative biological effectiveness of alpha-particle emitters in vivo at low doses

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Radiation Research; (United States)

DOI:https://doi.org/10.2307/3578710· OSTI ID:6551410

Howell, R W; Azure, M T; Narra, V R; Rao, D V ^[1]

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1. Univ. of Medicine and Dentistry of New Jersey, Newark, NJ (United States)

The therapeutic potential of radionuclides that emit [alpha] particles, as well as their associated health hazards, have attracted considerable attention. The [sup 224]Ra daughters [sup 212]Pb and [sup 212]Bi, by virtue of their radiation properties which involve emission of [alpha] and [beta] particles in their decay to stable [sup 208]Pb, have been proposed as candidates for radioimmunotherapy. Using mouse testes as the experimental model and testicular spermhead survival as the biological end point, the present work examines the radiotoxicity of [sup 212]Pb and its daughters. When [sup 212]Pb, in equilibrium with its daughters [sup 212]Bi, [sup 212]Po and [sup 208]Tl, was administered directly into the testis, the dose required to achieve 37% survival (D[sub 37]) was 0.143 [+-] 0.014 Gy and the corresponding RBE of the mixed radiation field was 4.7 when compared to the D[sub 37] for acute external 120 kVp X rays. This datum, in conjunction with our earlier results for [sup 210]Po, was used to obtain an RBE-LET relationship for [alpha] particles emitted by tissue-incorporated radionuclides: RBE[sub [alpha]] = 4.8 - 6.1 x 10[sup [minus]2] LET + 1.0 x 10[sup [minus]3] LET[sup 2]. Similarly, the dependence of RBE on [alpha]-particle energy E[sub [alpha]] was given by RBE[sub [alpha]] = 22 E[sub [alpha]][sup [minus]0.73]. These relationships, based on in vivo experimental data, may be valuable in predicting biological effects of [alpha]-particle emitters. 46 refs., 6 figs.

• OSTI ID: 6551410
• Journal Information: Radiation Research; (United States), Journal Name: Radiation Research; (United States) Vol. 137:3; ISSN 0033-7587; ISSN RAREAE
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
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& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ALPHA PARTICLES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
CALCULATION METHODS
CHARGED PARTICLES
DOSE-RESPONSE RELATIONSHIPS
ENERGY TRANSFER
EVEN-EVEN NUCLEI
GONADS
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
IMMUNOTHERAPY
IRRADIATION
ISOTOPES
LEAD 212
LEAD ISOTOPES
LET
LOW DOSE IRRADIATION
MALE GENITALS
MAMMALS
MEDICINE
MICE
NUCLEAR MEDICINE
NUCLEI
ORGANS
RADIATION EFFECTS
RADIOIMMUNOTHERAPY
RADIOISOTOPES
RADIOLOGY
RADIOTHERAPY
RBE
RODENTS
TESTES
THERAPEUTIC USES
THERAPY
USES
VERTEBRATES