Comparative assessment of single-dose and fractionated boron neutron capture therapy

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Radiation Research

DOI:https://doi.org/10.2307/3578951· OSTI ID:186114

Coderre, J A; Micca, P L; Fisher, C D ^[1]

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1. Brookhaven National Laboratory, Upton, NY (United States); and others

The effects of fractionating boron neutron capture therapy (BNCT) were evaluated in the intracerebral rat 9L gliosarcoma and rat spinal cord models using the Brookhaven Medical Research Reactor (BMRR) thermal neutron beam. The amino acid analog p-boronophenylalanine (BPA) was administered prior to each exposure to the thermal neutron beam. The total physical absorbed dose to the tumor during BNCT using BPA was 91% high-linear energy transfer (LET) radiation. Two tumor doses of 5.2 Gy spaced 48 h apart (n = 14) or three tumor doses of 5.2 Gy, each separated by 48 h (n = 10), produced 50 and 60% long-term (>1 year) survivors, respectively. The outcome of neither the two nor the three fractions of radiation was statistically different from that of the corresponding single-fraction group. In the rat spinal cord, the ED{sub 50} for radiation myelopathy (as indicated by limb paralysis within 7 months) after exposure to the thermal beam alone was 13.6 {+-} 0.4 Gy. Dividing the beam-only irradiation into two or four consecutive daily fractions increased the ED{sub 50} to 14.7 {+-} 0.2 Gy and 15.5 {+-} 0.4 Gy, respectively. Thermal neutron irradiation in the presence of BPA resulted in an ED{sub 50} for myelopathy of 13.8 {+-} 0.6 Gy after a single fraction and 14.9 {+-} 0.9 Gy after two fractions. An increase in the number of fractions to four resulted in an ED{sub 50} of 14.3 {+-} 0.6 Gy. The total physical absorbed dose to the blood in the vasculature of the spinal cord during BNCT using BPA was 80% high-LET radiation. It was observed that fractionation was of minor significance in the amelioration of damage to the normal central nervous system in the rat after boron neutron capture irradiation. 30 refs., 5 figs., 3 tabs.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 186114
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 3 Vol. 144; ISSN 0033-7587; ISSN RAREAE
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL RADIATION EFFECTS
BORON
BRAIN
CENTRAL NERVOUS SYSTEM
COMPARATIVE EVALUATIONS
DOSE-RESPONSE RELATIONSHIPS
ENERGY TRANSFER
FRACTIONATED IRRADIATION
LET
NEUTRON CAPTURE THERAPY
RATS
SARCOMAS
SPINAL CORD