Radiotherapy to the head and neck can cause temporary side effects, such as a sore mouth or throat and difficulty swallowing. Side effects can be mild or more severe, depending on:
- the area of the head and neck treated
- the dose of radiotherapy
- the length of your treatment.
They are usually more severe if you have radiotherapy combined with chemotherapy (chemoradiation).
Side effects usually begin to develop after one to two weeks of radiotherapy. They may continue to get worse for 7–10 days after treatment ends before gradually improving. Most people find that side effects have noticeably improved 6–12 weeks after radiotherapy has ended.
Sometimes radiotherapy can cause long-lasting side effects or new side effects that develop months or even years later. These are called late or long-term effects. Two of the most common late effects are a dry mouth and an increased risk of tooth decay. Your specialist can tell you whether your treatment may cause any late effects.