Title: Specific absorbed fractions of energy from internal photon sources in brain tumor and cerebrospinal fluid

Abstract

Transferrin, radiolabeled with In-111, can be coinjected into glioblastoma multiforme lesions, and subsequent scintigraphic imaging can demonstrate the biokinetics of the cytotoxic transferrin. The administration of [sup 111]In transferrin into a brain tumor results in distribution of radioactivity in the brain, brain tumor, and the cerebrospinal fluid (CSF). Information about absorbed radiation doses to these regions, as well as other nearby tissues and organs, is important for evaluating radiation-related risks from this procedure. The radiation dose is usually estimated for a mathematical representation of the human body. We have included source/target regions for the eye, lens of the eye, spinal column, spinal CSF, cranial CSF, and a 100-g tumor within the brain of an adult male phantom developed by Cristy and Eckerman. The spinal column, spinal CSF, and the eyes have not been routinely included in photon transport simulations. Specific absorbed fractions (SAFs) as a function of photon energy were calculated using the ALGAMP computer code, which utilizes Monte Carlo techniques for simulating photon transport. The ALGAMP code was run three times, with the source activity distributed uniformly within the tumor, cranial CSF, and the spinal CSF volumes. These SAFs, which were generated for 12 discrete photon energies ranging frommore » 0.01 to 4.0 MeV, were used with decay scheme data to calculate [ital S]-values needed for estimating absorbed doses. [ital S]-values for [sup 111]In are given for three source regions (brain tumor, cranial CSF, and spinal CSF) and all standard target regions/organs, the eye and lens, as well as to tissues within these source regions. [ital S]-values for the skeletal regions containing active marrow are estimated. These results are useful in evaluating the radiation doses from intracranial administration of [sup 111]In transferrin.« less

Authors:

Evans, J F ^[1]; Stubbs, J B ^[2]

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+ Show Author Affiliations

1. Nuclear Engineering Program, Ohio State University, Columbus (Ohio (United States))
2. Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831-0117 (United States)

Publication Date:

Wed Mar 01 00:00:00 EST 1995

OSTI Identifier:

6481097

DOE Contract Number:  

AC05-76OR00033

Resource Type:

Journal Article

Journal Name:

Medical Physics; (United States)

Additional Journal Information:

Journal Volume: 22:3; Journal ID: ISSN 0094-2405

Country of Publication:

United States

Language:

English

Subject:

61 RADIATION PROTECTION AND DOSIMETRY; 63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 62 RADIOLOGY AND NUCLEAR MEDICINE; BRAIN; NEOPLASMS; CEREBROSPINAL FLUID; INTERNAL IRRADIATION; A CODES; INDIUM; PHANTOMS; SPATIAL DOSE DISTRIBUTIONS; TRANSFERRIN; BIOLOGICAL MATERIALS; BODY; BODY FLUIDS; CENTRAL NERVOUS SYSTEM; COMPUTER CODES; DISEASES; ELEMENTS; GLOBULINS; GLOBULINS-BETA; IRRADIATION; MATERIALS; METALLOPROTEINS; METALS; MOCKUP; NERVOUS SYSTEM; ORGANIC COMPOUNDS; ORGANS; PROTEINS; RADIATION DOSE DISTRIBUTIONS; STRUCTURAL MODELS; 560101* - Biomedical Sciences, Applied Studies- Radiation Effects- Dosimetry & Monitoring- (1992-); 560151 - Radiation Effects on Animals- Man; 550604 - Medicine- Unsealed Radionuclides in Therapy- (1980-)