Biomaterial Database

Synergism between hyperthermia, ultrasound and gamma irradiation. 1991

P Loverock, and G ter Haar

Physics Department, Institute of Cancer Research, Sutton, Surrey, England.

Hyperthermia is now established as a successful therapy for some tumours. It has been found that, for some tumours, the combination of heat and ionizing radiation is more effective than either type of treatment on its own. Ultrasound is commonly used to produce hyperthermia. We have therefore studied the effect of combined heat, ultrasound and 60Co gamma irradiation treatments on suspension cultures of V79 Chinese hamster lung fibroblasts. Cells were exposed to 43 degrees C hyperthermia with or without simultaneous continuous wave ultrasound (2.6 MHz, 2.3 W cm-2) either before or after 60Co gamma exposure (428 c Gy). It was found that when the two types of exposure followed one immediately after the other, then the ultrasound exposure increased the amount of cell killing produced by the combination of heat and ionizing radiation, whether the heat or the ionizing radiation came first. If an interval for repair of 72 minutes was left between the heat and ionizing radiation, then this enhancement was lost. The increase in cell killing produced by the ultrasound is shown to be caused by a mechanism that is nonthermal in origin.

UI	MeSH Term	Description	Entries
D006979	Hyperthermia, Induced	Abnormally high temperature intentionally induced in living things regionally or whole body. It is most often induced by radiation (heat waves, infra-red), ultrasound, or drugs.	Fever Therapy,Hyperthermia, Local,Hyperthermia, Therapeutic,Thermotherapy,Induced Hyperthermia,Therapeutic Hyperthermia,Therapy, Fever,Local Hyperthermia
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D003037	Cobalt Radioisotopes	Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.	Radioisotopes, Cobalt
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D005720	Gamma Rays	Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.	Gamma Wave,Gamma Radiation,Nuclear X-Rays,Radiation, Gamma,X-Rays, Nuclear,Gamma Radiations,Gamma Ray,Gamma Waves,Nuclear X Rays,Nuclear X-Ray,Ray, Gamma,Wave, Gamma,Waves, Gamma,X Rays, Nuclear,X-Ray, Nuclear
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014465	Ultrasonics	A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.	Ultrasonic