Comparative in vitro microdosimetric study of murine- and human-derived cancer cells exposed to alpha particles.
Radiat Res
; 177(3): 280-7, 2012 Mar.
Article
in En
| MEDLINE
| ID: mdl-22077335
ABSTRACT
Diffusing alpha-emitter radiation therapy (DaRT) is a proposed new form of brachytherapy using α particles to treat solid tumors. The method relies on implantable ²²4Ra-loaded sources that continually release short-lived α-particle-emitting atoms that spread inside the tumor over a few millimeters. This treatment was demonstrated to have a significant effect on tumor growth in murine and human-derived models, but the degree of tumor response varied across cell lines. Tumor response was found to correlate with the degree of radionuclide spread inside the tumor. In this work we examined the radiosensitivity of individual cells to determine its relationship to tumor response. Cells were irradiated in vitro by α particles using a ²²8Th irradiator, with the mean lethal dose, D0, estimated from survival curves generated by standard methods. The results were further analyzed by microdosimetric tools to calculate z0, the specific energy resulting in a survival probability of 1/e for a single cell, which is considered to better represent the intrinsic radiosensitivity of individual cells. The results of the study demonstrate that, as a rule, tumors that respond more favorably to the DaRT treatment are also characterized by higher intrinsic cellular radiosensitivities, with D0 ranging from 0.7 Gy to 1.5 Gy for the extreme cases and z0 following the same trend.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Alpha Particles
Limits:
Animals
/
Humans
Language:
En
Journal:
Radiat Res
Year:
2012
Document type:
Article
Affiliation country:
Israel