What are the different types of radiation therapy?
Radiation therapy uses rays of high energy to destroy the cancer cells. For most patients with Hodgkin lymphoma (HL), radiation therapy is a part of lymphoma Hodgkin treatment. This is especially useful when HL is in only one part of the body.
Radiation is given after chemotherapy for classic Hodgkin lymphoma particularly when the mass of the tumor is large or bulky. Chemotherapy or radiation alone will not necessarily cure the lymphoma, but combination of all therapies can work together. Radiation therapy can also be used on its own to treat some forms of nodular Hodgkin lymphoma (NHLPL) prevalent in the lymphoma.
How is radiation therapy given?
Carefully focussed radiation beams are delivered from a machine to treat HL. It is called beam radiation from outside. The radiation team takes necessary measurements to determine the angles for targeting the radiation beams and the dose required before treatments begin. This planning session is called simulation and it includes imaging tests like CT or PET scans. Casts, body molds, and head rests can be made to keep you in the position during the course of treatment. Other parts of the body may be protected by blocks or shields. You may be told to keep your breath held for a short time. The objective is to focus the radiation on cancer in order to limit the effect on healthy tissues.
For many weeks, radiation therapies are most commonly given 5 days a week. The procedure is painless but it might also be important to sedate for lymphoma in children to make sure they don’t move during the procedure. Modern imaging tests can very accurately identify HL sites, which helps doctors target the radiation only to the lymphoma while sparing nearby normal tissues. This can help to limit side effects.
Other radiation treatment modalities include:
- Involved site radiation therapy (ISRT)
- Involved field radiation therapy (IFRT)
- Extended field radiation
- Total body irradiation
Side effects of radiation therapy include:
- Skin changes in areas getting radiation, ranging from redness to blistering and peeling
- Dry mouth
Radiation therapy can also have long-lasting effects including:
- An increased risk of another cancer in the body portion that has been exposed to radiation
- Damage to the thyroid gland that is capable of influencing thyroid hormone production. It can cause tiredness and weight gain
- Increased risk of heart failure and radiation to chest lung problems
- An increased risk of stroke years later, following neck radiation
- Slow growth in children’s bones
Doctors carefully measure the exact dose of radiation required to minimize the risk of side effects, and aim the radiation beams as precisely as they can.