Effect of size of lymph node metastases on the radiation response: influence of misonidazole

Journal Article · Mon Sep 01 04:00:00 EDT 1980 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575351· OSTI ID:7057607

Courdi, A; Malaise, E P

Metastatic lymph nodes of EMT6 tumors growing in athymic nude mice were used at different sizes and their radiosensitivity was tested with the in vitro colony method. Following the administration of 1250 rad, the surviving fraction in air-breathing animals was found to be dependent on the size of these metastases, expressed either in weight or in cell yield per lymph node. The increasing radioresistance with increase in size was probably due to the presence of higher hypoxic fraction in big nodes (0.43 in nodes weighing more than 320 mg vs 0.10 in nodes less than 80 mg). The surviving fraction after irradiation in acutely hypoxic conditions (asphyxiated animals) or in fully oxygenated ones (in vitro) was not size dependent. Great variations were observed in the radiosensitivity of small metastatic nodes, whereas bigger metastases had a more homogeneous response. The effect of the radiosensitizer misonidazole at a dose of 0.3 mg/g was assessed on lymph node metastases of different sizes. In the presence of the drug, the survival level of big and small metastases differed by a factor of 2.2, as opposed to 4.3 in untreated metastases. This suggests that the radiosensitization is less pronounced in metastases containing a smaller hypoxic fraction.

• Research Organization: Institut Gustave-Roussy, Villejuif, France
• OSTI ID: 7057607
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 83:3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
560152 -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
ANOXIA
DATA
DRUGS
EXPERIMENTAL DATA
IN VITRO
INFORMATION
LYMPH NODES
LYMPHATIC SYSTEM
MAMMALS
MEDICINE
METASTASES
MICE
NUMERICAL DATA
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
RESPONSE MODIFYING FACTORS
RODENTS
SIZE
SURGERY
SURVIVAL CURVES
THYMECTOMY
VERTEBRATES
WEIGHT