Renaissance of 224 Ra for the treatment of ankylosing spondylitis: clinical experiences

Radium (224Ra) is commercially available again for the treatment of ankylosing spondylitis. Twenty patients suffering from ankylosing spondylitis were treated with weekly intravenous (i.v.) injections of 1 MBq 224Ra for 10 weeks. Therapeutic effect was measured by C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and full blood count, as well as a completion of the Bath ankylosing spondylitis functional index (BASFI) questionnaire. Follow-up was done after three and six months. At the end of the treatment course pain and movement restrictions had improved subjectively in 12 out of 20 patients. These patients were also able to discontinue or reduce their analgesic or anti-inflammatory medications. Subjective improvement was well correlated with a reduction of CRP by 45% and BASFI by 73%. At the six-month follow-up, ten patients reported a lasting improvement, whereas two had suffered a relapse. A late therapeutic response after three months was seen in a single patient only. Patients who did not respond to radium had lower initial levels of acute-phase reactants and peripheral joint involvement. Only mild side-effects, e.g. temporary worsening of pain, were observed. Leukocytes and platelets reversibly decreased by 25%, respectively. It is concluded that 224Ra is an effective and safe treatment for ankylosing spondylitis.

18F-FDG for the staging of patients with differentiated thyroid cancer: comparison of a dual-head coincidence gamma camera with dedicated PET

Coincidence imaging with a dual-head gamma camera may offer a cost-effective alternative to dedicated PET. The aim of this study was to compare the diagnostic accuracy of coincidence imaging and PET in patients with differentiated thyroid cancer. Thirty-one patients were studied after thyroidectomy and radioiodine ablation. They were injected with a single dose of 300 MBq 18F-FDG. Scanning was performed on a dedicated PET system after 1 hr, and on a coincidence gamma camera after 4 hrs. Based on a lesion-by-lesion comparison, coincidence imaging and PET concurred in 69% of 118 lesions. Based on lesion size, concurrence was 96% in lesions larger than 1.5 cm, and 62% in those between 1 and 1.5 cm. Lesions smaller than 1 cm could not be identified with coincidence imaging. Identical staging was obtained with coincidence imaging and PET in 26/31 patients (84%). In four patients FDG accumulating lesions were shown by both the coincidence camera and the dedicated scanner, but not detectable with any other imaging means and were confirmed histologically on surgery. Although a coincidence camera is technically inferior to a dedicated PET scanner, it may provide clinically useful results in situations were a lesion of sufficient size and FDG uptake is to be expected, e.g. when evaluating a known lesion for malignancy.