New method for the evaluation of the response of cultured cell lines to continuous low-dose-rate irradiation from encapsulated iridium-192 seeds with hyperthermia.
A new method was designed to investigate and evaluate the biological effectiveness of hyperthermia combined with continuous low-dose-rate irradiation (CLDRI) from encapsulated iridium-192 seed sources on glioma cells in vitro using the MTT assay. The system consists of 10 iridium seeds contained in a catheter bent into a circle, which is placed on a culture plate containing the cells. The effects of CLDRI and CLDRI combined with hyperthermia on a cultured rat glioma cell line (C-6) were studied. The number of surviving cells decreased as the total radiation dose increased. There was no significant difference in survival rates at dose rates of 0.1 Gy/hr and of 0.2 Gy/hr (p = 0.2811). An additive effect was observed in the cells treated with hyperthermia at 41 degrees C and 42 degrees C, combined with CLDRI, and synergistic effect between the two treatment modalities was observed at 43 degrees C. This new device is less expensive, easily reproducible, and can also be performed easily enough to examine a large number of samples in a short time period for sensitivity testing.
Adachi
H
H
Department of Neurological Surgery, Okayama University Medical School.
Matsumoto
K
K
Kunishio
K
K
Furuta
T
T
Ohmoto
T
T
D000818:Animals; D001918:Brachytherapy; D001932:Brain Neoplasms; D002470:Cell Survival / Q000528:radiation effects*; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005910:Glioma; D006979:Hyperthermia, Induced; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D051381:Rats; D014407:Tumor Cells, Cultured / Q000528:radiation effects*
D007496:Iridium Radioisotopes