Treatment of secondary hyperparathyroidism with low dose intermittent calcitriol in hemodialysis patients. Imaging and cost analysis.

Calcitriol therapy is effective in the treatment of secondary hyperparathyroidism both during intravenous and oral administration, but there are doubts about the length of therapy and the duration of results. There are conflicting reports about results in size and activity of enlarged glands studied by ultrasound and double-tracer-subtraction-scintigraphy (DTSS). In 12 patients, 1 microgram of calcitriol was administered three times a week, intravenously and orally in alternate modes, for 46 weeks (therapy period) and orally for 46 weeks (follow-up period). During therapy, parathyroid hormone levels decreased in all patients, and in eight decreased by about 50% and were maintained at low levels during follow-up in five patients. Nine enlarged glands were detected by ultrasonography at the start of the study, and four hotspots were detected by DTSS; ultrasonography and DTSS were repeated at the end of the therapy and at the end of the follow-up: ultrasonography did not yield any significant variation in size, while one hot spot disappeared on DTSS. Basing their judgment on the lower cost of oral rather than intravenous administration, and on the good results of oral therapy, the authors stress the advisability of taking into account clinical and financial considerations before choosing the route of administration.

Usefulness of 99mTc-MIBI stress myocardial SPECT bull's-eye quantification in coronary artery disease.

99mTc-methoxy-isobutyl isonitrile (MIBI) myocardial SPECT quantification performed using a Bull's-eye polar map, was evaluated and compared with visual analysis in 120 patients with proven or suspected CAD. The study series comprised 106 men and 14 women, age 37-75 years (mean 51 +/- 6), 68 of whom had had a prior myocardial infarction. Coronary angiography was taken as the gold standard: one-vessel disease was present in 24 patients, two-vessel disease in 39, and three-vessel disease in 44, whereas no significant stenosis was documented in 13 cases. Forty age-matched subjects (26 men, 14 women), with less than a 5% chance of having CAD, were enrolled to establish the normal database for males and females. ROC analysis was used to calculate the optimal thresholds for the definition of the disease extension in each vascular territory of the Bull's-eye polar map: 10% for LAD, 8% for LCX, and 20% for RCA territory. The sensitivity/specificity ratio of the scintigraphy was: 75/82% with the visual and 78/74% with the quantitative analysis for LAD; 60/90% with visual and 72/64% with visual and 70/62% with quantitative analysis for RCA territory. The sensitivity/specificity ratios for the CAD diagnosis were similar with the visual and the Bull's-eye analysis in 92/61% and 93/61% respectively. Bull's-eye analysis agreed with visual analysis in 296/360 vessels. Two and three-vessel disease were most frequently observed using the Bull's-eye approach.(ABSTRACT TRUNCATED AT 250 WORDS)