NOT even the top medical minds are completely sure how it works, but radiotherapy is providing effective pain relief for patients suffering from bone cancer.

Studies have found that 80 per cent of patients who underwent the non-invasive treatment reported a significant reduction in pain.

Dr Margaret Latham, a radiation oncologist, says that most patients treated for bone cancer are stage four, when the cancer has become metastatic and spread from its original site through the bloodstream.

“Pretty much any cancer can spread to bones, apart from the non melanoma skin cancers which don’t tend to do that,” she says.

“The majority of cancers found early however don’t tend to spread.

• Comparison between a VMAT treatment plan (left) and a conventional treatment plan (right). The VMAT technique provides maximum radiation dose to the target tumour area (in this case to a metastasis in the spine), whilst allowing the radiation oncologist to spare neighbouring normal healthy organs and tissues (in this case the bowel and the kidneys).

“Cancer in the bones can cause pain, and weakness which can leads to fractures and breaks.

“The backbone, hip and pelvic bones tend to be sites where we find bone cancer, but it can affect affect any bone in the body, although many are less common.

“With cancer in the backbone, you can still have pain when your lying still in bed, which is different from say a mechanical injury, which tends to be sore when you’re moving around.”

The non-invasive radiotherapy treatment takes around 15 minutes and the number of sessions can vary depending on the patient’s medical circumstances, but generally they take place over a couple of weeks.

Bone treatment is usually palliative, making life for patients with later stage cancer as comfortable as possible.

Dr Latham says it’s not fully understood how radiation therapy reduces the pain.

“You do see pain responses before you see any changes in the bone, in terms of strengthening and improvement on a CT scan,” she says.

“There are probably things in the body that change to take away the pain.

“No one fully understands exactly how it works, but it does, and 80 per cent of people report pain relief; while if it was a placebo it would only be around 10 per cent.”

Genesis CancerCare centres in Bunbury, Joondalup, Murdoch and Wembley offer VMAT—volumetric-modulated arc therapy—a technique which reduces any potential side-effects patients may experience.