What should you know about medical imaging and radiotherapy?

Medical imaging helps the radiotherapy team locate a tumour, plan treatment around nearby tissues and review changes over time. Different scans answer different questions. Your team chooses imaging according to the body area, the treatment goal and information already available.

Before treatment, a planning scan maps the target and nearby organs. You may need to lie in the same position used for treatment, and a support or marking system may help you return to that position. The team uses the images to shape radiation delivery and protect healthy tissue as far as possible.

During follow-up, imaging may help the team assess the treated area, symptoms and other examination findings. A scan change does not always show the whole treatment response by itself, so the timing and type of scan matter. Radiotherapy may be used for conditions such as [Breast Cancer](/conditions/breast-cancer/) or [Brain Tumour](/conditions/brain-tumour/), among others.

Tell the team if you might be pregnant, have an implanted device, have difficulty lying flat or need help with movement. Ask whether you should eat, drink or take medicines as usual. Wear comfortable clothing and follow instructions about keeping still; small position changes can affect the treatment plan.

Keep a record of new skin changes, tiredness, pain, bowel changes or urinary symptoms after treatment. Do not stop prescribed medicines without advice. Your centre can explain which imaging appointments are for planning and which are for review.

Contact the treatment team promptly for worsening breathlessness, repeated vomiting, inability to drink, a new seizure, sudden weakness, severe headache or confusion. Seek emergency help for collapse, severe breathing difficulty or sudden one-sided weakness. These symptoms need assessment on their own; they do not establish that a scan finding represents cancer.

Which scan is being used for planning, and what will it show? Will I need contrast or special preparation? How will you protect nearby organs? When should I expect follow-up imaging? Which symptoms should prompt a same-day call?