A very uncommon, late side effect of radiotherapy to the pelvic area is damage to the bones in the pelvic area. Fine, hair-line cracks may occur, known as pelvic insufficiency fractures. If this happens, it can cause pain and may make it difficult to walk and move around. The changes in the bone may cause a dull, constant ache, which you may worry is due to your cancer having spread to the bone. If you have dull aching in the bone that lasts for more than a few weeks, your doctors will need to do tests (a bone scan or MRI scan or possibly a biopsy of the affected area) to find out the cause. If the bone is weakened enough it may break (fracture) but this is very rare. The strength of your bones can be checked using a bone density scan.

It is important to be aware of the signs of bone problems so you can let your doctor know if they occur. Radiotherapy damage to the bones is uncommon, so it is likely that if you have any symptoms they will have another cause. The section on pelvic pain discusses other causes of bone pain.

Dealing with bone damage

If bone damage occurs it is usually permanent and you will be given treatment to relieve any symptoms. If you have pain, this can usually be controlled with painkillers. Drugs known as bisphosphonates can strengthen the bone and a diet rich in calcium can help pelvic insufficiency fractures to heal. You may also need to see a physiotherapist or occupational therapist if the damaged bone makes it difficult for you to move around and carry out daily activities.