Radiation Therapy

Radiation is the use of forms of energy rays, such as x-rays and gamma rays, to kill cancer cells. While radiation therapy affects both normal and cancer cells, because cancer cells do not repair themselves as well as normal cells, they should die or shrink after treatment.

Radiation therapy is usually reserved for high-risk or advanced cases of melanoma where surgery is not possible or may be complicated. It is rarely used to treat primary melanoma, except in cases where patients are not good candidates for surgery or refuse surgical treatment.

The main role of radiation therapy is to relieve symptoms of melanoma that have metastasized to areas such as the brain or bone. Although it cannot cure advanced melanoma, it can frequently shrink tumors that cause discomfort. In the case of brain metastases, it is the primary treatment, with the goal being to relieve symptoms such as partial paralysis, headaches, and seizures.

Although still considered an “unproven treatment,” radiation may be targeted to the regional lymph node basin to prevent tumor recurrence after surgery.

Types of Radiation Therapy by Stage

Stage III Patients

Purpose: For those with multiple or large nodes, radiotherapy is used after surgery to prevent the tumors from returning. If tumors are hard to remove, radiotherapy can be used to control the disease locally.

How it Works: Radiation damages both normal cells and cancer cells, but normal cells are better able repair themselves. With adjuvant therapy, radiation is given to help prevent cancer cells from growing back in that region.

Which Patients: Stage III patients who are at high risk for tumor recurrence in and around the lymph node region because they have multiple nodes with melanoma (≥3 nodes), or large nodes (>3 cm), or lymph nodes with extracapsular extension. It is also used for Stage III patients who have tumors that are hard to remove because of their location. These include thick tumors or those on the head and neck where the surgeon is unable to get an adequate margin around the tumor.

How It’s Given: External Beam Radiation Therapy refers to radiation that is coming from an energy source outside the body and is directed to a target inside the body.

  • Patients receive treatment in a hospital or at an outpatient treatment center.
  • In most cases, a linear accelerator, a high-energy x-ray machine, directs radiation to the affected area.
  • A total dose of external beam radiation therapy is fractionated, or divided into several smaller doses (fractions), over a period of days (conventional fractionation).
  • Treatment lasts a few minutes at a time, usually for 5 days a week over the course of 2 weeks.
  • Hypofractionation, is one of the treatments that is being explored to see the effectiveness of giving higher doses of radiation in fewer treatments, and the delivery of more than one dose of radiation within the same day.

Effectiveness: Radiation therapy does improve the control of resected disease in patients with high-risk features. However, it has not been shown to reduce the risk of distant disease.

Side Effects: The side effects of radiation therapy vary by location on the body, but can include hearing loss, skin breakdown, bone exposure, ear pain, hair loss, and lymphedema.

Stage IV Patients

Purpose: May relieve symptoms by shrinking the tumors. Where there is a single tumor it is hoped that in combination with newer medical treatments, this may prolong survival.

How it Works: Radiation damages both normal cells and cancer cells, but normal cells are better able to repair themselves. Radiation is given to help shrink the tumors and with the goal of relieving symptoms.

Which Patients: Stage IV patients whose melanoma has spread to the bones, other parts of the body, or where there is a single tumor.

How It’s Given: External Beam Radiation Therapy refers to radiation that is coming from an energy source outside the body and is directed to a target inside the body.

  • Patients receive treatment in a hospital or at an outpatient treatment center.
  • In most cases, a linear accelerator, a high-energy x-ray machine, directs radiation to the affected area.
  • A total dose of external beam radiation therapy is fractionated, or divided into several smaller doses (fractions), over a period of days (conventional fractionation).
  • Treatment lasts a few minutes at a time, usually for 5 days a week over the course of 2 weeks.
  • Hypofractionation, is one of the treatments that is being explored to see the effectiveness of giving higher doses of radiation in fewer treatments and the delivery of more than one dose of radiation within the same day.

Effectiveness: Radiation therapy is used with the goal of relieving symptoms. This is called palliative therapy. The radiation therapy is not expected to cure the cancer but it may help shrink it for a period of time.

Side Effects: The side effects of radiation therapy vary by location on the body, but can include hearing loss, skin breakdown, bone exposure, ear pain, hair loss, and lymphedema.

Stage IV Patients with Brain Metastases

Purpose: To control the growth of or shrink melanoma tumors in the brain, in a precise manner in order to maximize effectiveness while minimizing side effects.

How it Works: 

  • SRS (stereotactic radiosurgery) uses several powerful beams of radiation located at different angles around the head which come together to focus precisely on the tumor.
  • Gamma Knife is one of the most advanced forms of SRS. The “knife” is formed by 201 intersecting beams of gamma radiation that deliver a concentrated dose to a precise area of the brain.
  • This noninvasive procedure is the preferred treatment for metastatic brain tumors that were previously considered inoperable or at a very high risk for standard brain surgery.

Which Patients: Stage IV patients with brain metastases.

How It’s Given:

  • Prior to the operation, imaging techniques including CT scans and MRIs are used to pinpoint tumor location.
  • One treatment session and one overnight hospitalization are all that are required. Gamma knife radiosurgery is available at many major medical centers.
  • SRS is most effective when there are only a few small metastases. Typically, patients who have too many brain metastases to be suitable for SRS may be treated with whole brain radiation (WBXRT).

Effectiveness: For certain patients, SRS followed by whole brain radiation provides useful palliation and may prolong survival.

Side Effects: SRS has less side effects than more diffuse radiation but still can cause hair loss, hearing loss, memory problems, and speech problems, depending on the location of the brain tumor.

Find a Melanoma Specialist

Related Content

Please keep me informed.

Receive comprehensive, breaking news about melanoma, research, legislation, and events.

  • This field is for validation purposes and should be left unchanged.