Microdosimetric model of astatine-211 labeled antibodies for radioimmunotherapy
Astatine-211 is an alpha-emitter with a short half-life (7.2 hr). This paper discusses the potential of /sup 211/At targeted by antibodies for tumor therapy and the possible advantage of /sup 211/At over beta- and gamma-emitting radionuclides such as /sup 131/I currently employed in the field of radioimmunotherapy. Since the longest range alpha-particle from /sup 211/At is only 67 microns and the rate of energy loss is high (track averaged linear energy transfer LT approximately 120 keV/micron), a disintegration of /sup 211/At produces a large and extremely localized deposition of energy. A Monte-Carlo model has been developed for studying the stochastic fluctuation of alpha-particle hits and energy deposition in cell nuclei in an attempt to determine the efficacy of /sup 211/At-labeled antibodies for tumor cell inactivation. Calculations have been performed for 2 extreme conditions: (a) the case of /sup 211/At retained in the capillary, and (b) for a homogeneous distribution of /sup 211/At-labeled antibody in the tumor. The results of these two calculations represent the boundary conditions between which any real solution must lie. Finally, developments to the model to include antibody transport across the capillary membrane and through the tumor tissue are discussed.
- Research Organization:
- MRC Radiobiology Unit, Chilton, Didcot, England
- OSTI ID:
- 5779909
- Journal Information:
- Int. J. Radiat. Oncol., Biol. Phys.; (United States), Vol. 13:11
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NEOPLASMS
RADIOIMMUNOTHERAPY
MICRODOSIMETRY
ANTIBODIES
ASTATINE 211
BIOLOGICAL HALF-LIFE
ENERGY TRANSFER
MATHEMATICAL MODELS
MONTE CARLO METHOD
ALPHA DECAY RADIOISOTOPES
ASTATINE ISOTOPES
BETA DECAY RADIOISOTOPES
DISEASES
DOSIMETRY
ELECTRON CAPTURE RADIOISOTOPES
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
IMMUNOLOGY
ISOTOPES
MEDICINE
NUCLEAR MEDICINE
NUCLEI
ODD-EVEN NUCLEI
RADIOIMMUNOLOGY
RADIOISOTOPES
RADIOLOGY
RADIOTHERAPY
THERAPY
550604* - Medicine- Unsealed Radionuclides in Therapy- (1980-)