Principles
Radiation therapy is used to kill cancer cells; however, normal cells are also damaged in the process. Currently, therapeutic doses of radiation can be targeted to tumors with great accuracy using linear accelerators (see radiation oncology); however, the normal liver tissue is very sensitive to external beam radiotherapy. Fortunately, malignancies (including primary and metastatic liver cancers) are often hypervascular; tumor blood supplies are often increased compared to those of normal tissue. Furthermore, the liver has a dual blood supply, receiving blood from both the hepatic artery and the portal vein. Hepatic malignancies derive most of their blood supply from the hepatic artery; whereas the normal liver derives most of its blood supply from the portal vein. Therefore, delivery of radioembolic particles through the branch of the hepatic artery supplying a tumor will preferentially lead to deposition of the particles in the tumor, while sparing normal liver from harmful side effects.
Read more about this topic: Selective Internal Radiation Therapy
Famous quotes containing the word principles:
“Only conservatives believe that subversion is still being carried on in the arts and that society is being shaken by it.... Advanced art today is no longer a cause—it contains no moral imperative. There is no virtue in clinging to principles and standards, no vice in selling or in selling out.”
—Harold Rosenberg (1906–1978)
“Government ... thought [it] could transform the country through massive national programs, but often the programs did not work. Too often they only made things worse. In our rush to accomplish great deeds quickly, we trampled on sound principles of restraint and endangered the rights of individuals.”
—Gerald R. Ford (b. 1913)
“Magic is akin to science in that it always has a definite aim intimately associated with human instincts, needs, and pursuits. The magic art is directed towards the attainment of practical aims. Like other arts and crafts, it is also governed by a theory, by a system of principles which dictate the manner in which the act has to be performed in order to be effective.”
—Bronislaw Malinowski (1984–1942)