Cobalt is a radiation source that constantly emits radiation. Shielding within a cobalt machine allows sale use of' this type of radiation for medical purposes. Early linear accelerators were built to mimic the cobalt machine's energy range. This compares to a 4 MV linear accelerator producing a beam that has a D-max of 1 cm. The linear accelerator produces more skin sparing and thus so-called radiation dermatitis is less commonly associated with this type of machine.
Treatment planning is crucial in producing the best results of therapy.
Of course, now there are many different energy linear accelerators. These have a much deeper D-max. That is an exceptionally powerful beam. For those with pelvic malignancies like prostate cancer or gynecologic malignancies such as cervix cancer and endometrial cancer, it is commonly utilized. For lung cancer treatment, it deposits the radiation deep within the lung, minimizing the effect on skin and superficial tissues.