Radiation Therapy:

High-dose radiation therapy, which shrinks the tumors, has been used for more than 50 years for treating Hodgkin's disease. High-dose radiation is generally reserved for adults. Radiation treatments are highly toxic for children and appear to add little benefit. In such young age groups radiation is mostly used if there are large areas of disease in the chest; otherwise, chemotherapy with possibly low-dose radiation is the best option with excellent survival rates.

Radiation Treatment Approaches

The two main types of radiation therapy are extended field radiation and involved field radiation.

Extended field radiation targets the diseased lymph nodes and surrounding healthy lymph nodes. Extended-field radiation is rarely given in combination with chemotherapy. Specific subtypes of extended field radiation are used depending on the location of the disease:

• If HD is above the diaphragm, “extended field radiation” is delivered to the neck, chest, and under arms (called the mantle field). Radiation is sometimes expanded to include lymph nodes in the upper abdomen.
• If cancer is below the diaphragm, an "inverted Y" field is sometimes used, in which radiation is directed at lymph nodes in the upper abdomen, spleen, and pelvis.
• Inverted Y-field radiation therapy combined with mantle-field radiation is called total nodal radiation.

Involved field radiation targets only lymph node regions that are known to have cancer, not the adjacent, uninvolved lymph node regions. Involved-field radiation is usually given after several rounds of chemotherapy.

In general, recent research suggests that extended-field radiation adds little survival advantage and carries a greater risk of serious side effects. Involved-field radiation is now becoming the preferred method. Some researchers recommend that involved-field radiation therapy plus chemotherapy should become the standard treatment for patients with early-stage Hodgkin� ' s disease who have a good prognosis. More research is needed before standard practice guidelines can be implemented.

Complications of Radiation

Infections. Infections may be a particular problem with radiation combined with chemotherapy. All patients should be vaccinated against the bacteria that often cause pneumonia and meningitis, and against the influenza virus.

Infertility. Radiation therapy to the pelvic area can adversely affect later fertility in women and men. Such negative effects may be worse in women; sperm usually recover within 5 years.

Heart Disease and Stroke. Radiation is associated with a future risk of heart disease, which includes atherosclerosis (hardening of the arteries) and diseases of the heart valves. Lower doses pose less risk. Recent research suggests that adults who survived childhood Hodgkin� ' s disease have a four times higher risk of having a stroke than healthy patients.

Fatigue. Fatigue is significant and chronic in many survivors. It is more highly associated with intensive chemotherapy, but it also may be a late response to radiation treatment.

Secondary Cancers. Second cancers (such as breast, stomach, lung, melanoma) may develop later in areas within or at the edge of the radiation area. Thyroid, respiratory tract, and digestive tract secondary cancers may affect patients who were treated as children. Lung cancer in survivors is highly associated with smoking after treatment, and no survivor should smoke. The risk for breast cancer increases significantly in women who receive chest radiation. The risk can persist for 25 years or more after radiotherapy, and lifetime monitoring (including frequent mammograms) is essential.

Thyroid Disorders. Hypothyroidism (underactive thyroid) occurs in a number of patients treated with radiation treatments. There is also a 5% chance for hyperthyroidism (overactive thyroid).

Impaired Growth in Children. Children and adolescents are at special risk for impaired bone growth.