The best treatment method for cancer depends on several factors, of which the most important are the site of cancer, type  of cancer, spread of the disease when diagnosed, general health of the patient etc. Some cancers are best removed by operation and are cured by this method. For some other types the best treatment is radiation: given externally,  [Teletherapy] which is administered with Cobalt or Linear accelerator units or by inserting radioactive needles [radium,caesium. Cobalt etc.] into the body [Brachy therapy] or by combining both external and brachy therapy methods. Certain cancers are treated by drugs [chemotherapy] only. Very often some cancers need all the three methods of treatment. The treating doctor choses the best method considering several of the above factors. In some cases surgery will remove a portion of the tumour, then treatment is continued by radiation. Radiation is given also to shrink the tumour so that a removal of the tumour by surgery can be done later.