Radiation therapy in the treatment of bone cancer
How is radiotherapy used to treat bone cancer?
Radiation therapy, also known as radiotherapy, employs high doses of radiation to kill cancer cells or shrink tumors. Low doses of radiation are used in X-rays to capture images of teeth and broken bones and in the diagnosis of bone cancer
Radiotherapy kills cancer cells and slows its growth by damaging their DNA. Destroyed DNA causes cells to die, and they are removed by the body. It takes days or weeks of treatment before DNA is damaged enough for cancer cells to die which continue to die after treatment has ceased.
Reasons why radiotherapy is used
1. It is used before surgery to try and shrink the tumor. It helps the surgeon remove the cancer completely. This means limb-sparing surgery is possible instead of an amputation.
2.It is used during surgery so it reaches the tumor straight without passing through the skin and other adjacent tissue.
3. It is used after surgery to reduce the risk of a recurrence of cancer. If surgery could not remove the tumor completely, radiotherapy helps to shrink it.
Kinds if radiotherapy
1. Intensity modulated Radiation therapy (IMRT)
This is a type of technique used in external beam radiotherapy (EBRT). Most commonly used, it uses sophisticated inverse computer programs to calculate varying doses of radiations that need to strike directly at the tumor from different angles. This allows safe administering of high doses increasing the chance for cure.
2. Proton therapy
This delivers less exposure to organs near the tumor. Proton treatment is popular for children for the same reason and is less riskier to robust and growing tissues.
3. Stereotactic radiosurgery
This is a sophisticated technique that involves highly specialized methods. It delivers very high doses of radiation directly to the tumors minimizing effects on surrounding tissues and consequently minimizing side effects. Usually performed in regions near the spine and the brain.
It is a form of internal radiation that delivers directly to the tumor itself. A common type is intraoperative radiotherapy in which a large single dose of radiation is delivered to the tumor during the surgery directly. Other types involve temporary or permanent radioactive seeds treating the insides of tumors.
Extracorporeal radiation is used as part of limb-salvage surgery and it involves dislodging the bone with the cancer and treating it with radiation and relodging it. Healing wound problems, loss of joint movement, change in limb length and fractures are potential side-effects.
Support for patients
Patients need to be educated and enough information and reassurance need to be given to prepare them before surgery. Parent-child communication needs to be supported by health professionals and RT nurses. Communication between parent and child is associated with emotional health when a parent has cancer or vice-versa.