Percutaneous calcitriol injection therapy (PCIT) for secondary hyperparathyroidism: multicentre trial

A multicentre trial of percutaneous calcitriol injection therapy (PCIT) was designed to evaluate its clinical usefulness. During a 12-week period, measurement of intact PTH concentration, and other parameters, and ultrasonography were carried out in conjunction with PCIT in 19 haemodialysis patients with secondary hyperparathyroidism and enlarged parathyroid glands (PTGs) that were resistant to vitamin D pulse therapy. Calcijex was injected directly into the PTG three times per week on the patient's non-dialysis days: eight patients received a 2 microg/ml preparation (group A) and 12 received 1 microg/ml (group B). A strong clinical effect was observed in group A compared with group B, which suggests that the effect of calcitriol by direct injection is stronger when there is a higher concentration of calcitriol in the PTG. In group B, the cases with an initial intact PTH concentration <1000 pg/ml and a single enlarged PTG had a good response to the treatment. Concentrations of calcium and phosphate were not significantly changed in either group. All cases had decreased blood flow in the PTG after three episodes of PCIT and, although the size of the PTG was unchanged, or even a little increased, immediately after the treatment, it decreased gradually over 2-6 weeks. PCIT may be effective for comparatively slight secondary hyperparathyroidism, but further investigation is necessary because there were comparatively few cases.