Microdosimetric model of astatine-211 labeled antibodies for radioimmunotherapy

Journal Article · Sun Nov 01 04:00:00 EST 1987 · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

DOI:https://doi.org/10.1016/0360-3016(87)90176-3· OSTI ID:5779909

Humm, J L

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), Journal Name: Int. J. Radiat. Oncol., Biol. Phys.; (United States) Vol. 13:11; ISSN IOBPD
• Country of Publication: United States
• Language: English

Related Subjects

550604* -- Medicine-- Unsealed Radionuclides in Therapy-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
ALPHA DECAY RADIOISOTOPES
ANTIBODIES
ASTATINE 211
ASTATINE ISOTOPES
BETA DECAY RADIOISOTOPES
BIOLOGICAL HALF-LIFE
DISEASES
DOSIMETRY
ELECTRON CAPTURE RADIOISOTOPES
ENERGY TRANSFER
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
IMMUNOLOGY
ISOTOPES
MATHEMATICAL MODELS
MEDICINE
MICRODOSIMETRY
MONTE CARLO METHOD
NEOPLASMS
NUCLEAR MEDICINE
NUCLEI
ODD-EVEN NUCLEI
RADIOIMMUNOLOGY
RADIOIMMUNOTHERAPY
RADIOISOTOPES
RADIOLOGY
RADIOTHERAPY
THERAPY