Cobalt therapy

As cobalt gun ( cobalt bomb) a therapeutic device for irradiation of cancerous tumors is known in the medicine.

It is a container made of lead or tungsten, in which many small holes or tubes are arranged in a space - like a fan, so that the intersection point ( focus) of their axes located outside the container. The holes are filled with small specimens from the radioactive cobalt isotope 60Co, but it can also be the cesium isotope 137Cs or its chemical compounds are used. At the smaller end of the spatial fan of the container with a movable closure is provided which releases the gamma radiation in the direction of the holes after its opening.

In the treatment apparatus and the patient is positioned so that the focus of the radiation impinges the tumor. However, his cells are destroyed by the added focus on the radiation dose. The fan- like arrangement for exposing the tumor to a higher radiation dose than the tissue between the tumor and the device. Nevertheless, it must be reckoned with this therapy always with the possibility of damage to the surrounding organs. Therefore, they should only be used when other options fail. It is then but a very effective therapy; if used improperly, however, it is often come to significant injuries - local radiation burns due to incorrect positioning or prolonged use.

The first device of this type was used in 1951 by the Canadian doctor Harold Johns at Victoria Hospital in Saskatoon / Saskatchewan. The pear-shaped form of this device, which arises from the fan-like arrangement of the holes, has helped him to the designation bomb. The radioactive content of these devices is very large ( around 1000 Curie = 37,000 GBq ), which is why the proper disposal of utmost importance. In the past there have been incidents to accidents, such as in 1987 when Goiânia accident and in 2000 to the nuclear accident in Samut Prakan. Therefore, the more expensive linear accelerators are used now increased.