a) Ankylosing Spondylitis

Ankylosing Spondylitis is an inflammatory arthropathy that is mostly hereditary in nature (90% of cases). The most important genetic factor is HLA-B27.

Between the 1930s and 1950s, a large number of patients with ankylosing spondylitis received radiotherapy to symptomatic sites or to the whole spine. Doses were often in the range of 20 Gy, delivered using orthovoltage beams. Case series report low rates of ersistant disease (10-20% at most) and most patients developed improved mobility.

Radiotherapy fell out of favour when it was realised that there was an increased risk of second malignancy with the treatment. Reviews of patients who received radiotherapy showed increased rates of mortality from leukaemia, bowel and other cancers. Bowel cancer is particularly important given the HLA-B27 molecule associated with both ankylosing spondylitis and ulcerative colitis.

Most cases are now treated with non-steroidal anti-inflammatory drugs, with more advanced therapy reserved for patients with progressive disease despite this. The most promising group of drugs are the TNF-alpha blockers, which have shown significant activity in the disease.

Radiotherapy has no role to play in the modern management of ankylosing spondylitis.