NCCN Guidelines for Patients
Part 6: A step-by-step treatment guide
Principles of radiation therapy
Radiation therapy is the use of high-energy rays to destroy cancer cells.
In selected patients, adjuvant radiation therapy may be used to treat the
primary melanoma tumor after wide excision based on certain factors.
These factors include desmoplastic melanoma removed with narrow
surgical margins, recurrent melanoma, or extensive neurotropism.
Neurotropism is when the melanoma cells are able to invade nerves.
Adjuvant radiation therapy may be used for regional melanoma if it’s
likely that the cancer will return in the area where nearby (regional)
lymph nodes were removed. This area is called the nodal basin. Adjuvant
radiation may be considered for the following situations:
• Visible nodal extracapsular extension (tumor in the lymph node has
grown beyond the edge of the node);
• Cancer in ≥4 lymph nodes;
• Lymph node contains ≥3 cm of tumor;
• Following surgery for lymph node recurrence.
Adjuvant radiation is more frequently recommended in the neck than
in other nodal basins. In the neck, adjuvant radiation therapy may be
considered if cancer is found in ≥2 enlarged lymph nodes and/or a lymph
node contains ≥2 cm of tumor.
Radiation may be used as palliative treatment for lymph node, satellite,
or in-transit metastases that can’t be treated with surgery. Palliative
radiation therapy may also be used to treat the symptoms caused by
A wide range of radiation doses and schedules are effective.
Treatment given after the
main (primary) treatment
A melanoma tumor with
dense connective tissue
cells throughout the body
Treatment for symptoms of
around the edge of a tumor
removed during surgery
treatment that removes
the whole tumor and some
surrounding normal tissue