Gamma radiation therapeutic

Until the mid-1950s, when improvements in the generation of penefiating X-rays made them the therapy of choice, cobalt-60 was widely used to treat cancer. This radioisotope emits beta and gamma radiation and has a half-life of 5.3 years. When used therapeutically... 

In general, the adverse effects of radium are believed to be the consequence of the radiation emitted from the element itself and its daughter products. Because there is already a considerable amount of information on the effects of radiation on humans and animals derived from studies on the effects of the atomic bomb and of therapeutic x-ray and gamma-ray treatments of malignancies, the experimental animal studies with radium have made no attempt to duplicate this information. They have instead concentrated on radium s most sensitive endpoint, cancer. For example, it can be predicted that the beta and gamma rays emitted by a radium source will produce local radiation burns and tissue damage when the source is placed on human or animal skin, hence there have been no valid reasons to conduct such studies with radium. 

Deterministic irradiation is applied in nuclear medicine for therapeutic purposes (chapter 19). For tumour treatment, large doses are delivered to selected tissues. Gamma rays emitted by °Co (up to 2 lO " Bq) or Cs (up to 2 lO Bq) are preferred for irradiation of deeply located organs. The doses transmitted to malignant tumours vary between about 10 and 100 Sv, and the individual responses of patients to certain radiation doses may vary appreciably. 

Some radionuclides are emitting a combined spectrum of radiation. One type of the radiation spectrum (alpha or beta) is used for its therapeutic properties the other type of the radiation spectrum (gamma) might be used for localisation of the tracer and the targeted tissue or for dosimetry. These radiopharmaceuticals are called theranostics. 

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