Response of a transplantable tumor to fractionated irradiation. III. Fast neutrons plus the radiosensitizer Ro-07-0582

Journal Article · Sun May 01 04:00:00 EDT 1977 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3574599· OSTI ID:7110119

Denekamp, J ^[1]; Morris, C; Field, S B

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1. Mount Vernon Hospital, Middlesex, Eng.

The response of a transplantable mammary carcinoma in CBA mice has been assessed using delay in tumor growth after irradiation. Dose-response curves have been obtained for tumors treated with single doses or with two or five fractions of cyclotron neutrons, given in the presence or absence of the hypoxic cell radiosensitizer Ro-07-0582. The results are compared with previously published X-ray data. A greater delay in tumor growth was observed for all treatments if the radiosensitizing drug was present. A radiation dose reduction factor (DRF) could be measured from the pairs of dose-response curves. The factor was 1.2 to 1.4 for single doses and 1.1 to 1.3 for two and five fractions when 0.67 mg/g of the drug was used before each irradiation. The effect of a smaller drug dose (0.15 mg/g) was tested with a single dose of neutrons and a smaller effect was observed (DRF = 1.1). These results, together with those of papers I and II, show that all three methods of overcoming the resistance of hypoxic cells (fractionation, radiosensitizers, fast neutrons) are effective, but less than optimal if used individually. Any combination of the three increases the therapeutic effectiveness. The most effective treatment tested, with this tumor, was five fractions of neutrons plus the radiosensitizer Ro-07-0582.

• OSTI ID: 7110119
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 70:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
ANOXIA
BARYONS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
DISEASES
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELEMENTARY PARTICLES
FAST NEUTRONS
FERMIONS
FRACTIONATED IRRADIATION
GLANDS
GROWTH
HADRONS
IRRADIATION
MAMMALS
MAMMARY GLANDS
MICE
NEOPLASMS
NEUTRONS
NUCLEONS
ORGANS
RADIATION EFFECTS
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
RESPONSE MODIFYING FACTORS
RODENTS
TRANSPLANTS
VERTEBRATES