Measurement of density and calcium in human atherosclerotic plaque and implications for arterial brachytherapy.

摘要: Abstract Purpose . To measure density of arterial plaque specimens for purposes improving calculation intravascular radiation dose. Methods and Materials In the described technique, mass specimen submerged in water is compared with its air. Thirty-three harvested from cadavers subsequently histologically classified (18 coronary, 15 noncoronary) were subjected to measurement, also assayed calcium using inductively coupled plasma optical emission spectroscopy (ICPOES). A dose point kernel (DPK) computer model extended heterogeneous media used determine delivered tissues stents labeled 32 P, 103 Pd, 131 Cs, based on measured values. Results Plaque identified as noncalcified (non-class VII) had an average 1.22 ± 0.03 g/cm 3 ( n = 19). calcified (Class 1.45 0.06 13). Density portions may be even higher because are heterogeneous. was found correlated weight percentage (R 2 0.67) histologic percent area calcification 0.58). Significant variations calculated according isotope, density, thickness. The assumption "all density" overestimates tissues. For 1-mm thick (class plaque, computed (via DPK model) decreased by 29%, 34%, 15%, Cs stents, respectively, model, when taken into account. Similar decreases expected catheter-based brachytherapy systems beta or low energy Conclusions This work has importance radioactive due dependence at distances between 0.1 mm away source. important both beta- gamma-based systems.