Involved-field radiation therapy (IFRT) is a term used for delivering radiation to only those areas of the body involved by lymphoma.
For example, if lymphoma affects the left side of the neck, IFRT will deliver radiation to the entire left side of the neck. If lymphoma affects two areas like the neck and the armpits, radiation will be delivered to these two sites only.
This term is used in comparison with extended field radiation therapy, which delivers radiation to larger areas of the body, including regions not immediately involved by lymphoma.
Most of the radiation treatment in Hodgkin and Non-Hodgkin lymphoma is now IRFT. Here are some situations where IFRT is used:
- Hodgkin lymphoma treatment – after 4 to 8 cycles of chemotherapy in stage I and II disease.
- Aggressive non-Hodgkin lymphoma treatment – after chemotherapy in stage I and II disease
- Follicular lymphoma treatment– as the only treatment in stage I disease.
- In any type of lymphoma when there is a residual mass after chemotherapy, or a small area of relapse after a period of remission with chemotherapy.
Most treatments with involved field radiation are completed in 4 to 5 weeks. The duration of treatment depends on the dose delivered. As IFRT is commonly given after chemotherapy, the dose is often based on how much disease remains after chemotherapy.