Comparison of 99mtechnetium-pertechnetate and 123iodide SPECT with FDG-PET in patients suspicious for breast cancer.

PURPOSE: Breast carcinomas express the Na(+)/I() symporter and may-albeit not a routine procedure-be imaged with (123)iodide ((123)I) and (99m)technetium-pertechnetate ((99m)TcO(4)(-)) scintigraphy. The aim of our prospective study was the comparison of (99m)TcO(4)(-)--and (123)I-single-photon emission computed tomography (SPECT) with (18)F-2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) in patients suspicious for breast cancer. METHODS: Twenty-nine (29) untreated patients suspected of having breast carcinoma were prospectively examined with thorax SPECT with (99m)TcO(4)(-) (n=19) or (123)I (n=10), respectively, and FDG-PET (n=29) prior to biopsy. Tumor-to-background ratios (TBRs) were calculated for SPECT findings. Mean and maximum standardized uptake values (SUVs) were calculated for PET findings. Findings were compared in an intra-individual lesion-to-lesion analysis. RESULTS: In 28 of 29 patients, malignancy was verified with histopathology. In imaging the primary tumor, sensitivities of (99m)TcO(4)(-)-SPECT, (123)I-SPECT, and FDG-PET were 63%, 67%, and 89%, respectively. TBR maximum was 2.6+/-1.1 in (99m)TcO(4)()-SPECT and 2.3+/-0.6 in (123)I-SPECT. In FDG-PET, mean tumor SUV was 4.1+/-4 and maximum tumor SUV was 5.4+/-5.1. In contrast to FDG-PET, (99m)TcO(4)()-SPECT was ineffective in imaging nodal and distant metastases in the thorax, and (123)I-SPECT failed in imaging lymph node infiltrations. Distant metastases were not present in patients of the (123)I group, and the value of (123)I-SPECT was not evaluated. CONCLUSIONS: In contrast to FDG-PET, (99m)TcO(4)(-) and (123)I-SPECT are ineffective in imaging breast carcinoma in clinical practice.

Cholesterol diet and effect of long-term withdrawal on plaque development and composition in the thoracic aorta of New Zealand White rabbits.

AIMS: Experimental study on plaque progression, regression and composition in atherosclerotic thoracic aorta of hypercholesterolemic rabbits after long-term withdrawal of cholesterol-enriched diet (CED). METHODS: Rabbits were fed 2% cholesterol for 6 weeks followed by withdrawal periods for 15, 23, 34, 68, or 78 weeks. Cholesterol, triglyceride, and phospholipids levels in blood and cholesterol concentrations in aorta were quantified. Plaque size and cellularity, phenotype of macrophages and smooth muscle cells were (immuno)histomorphometrically analyzed in segments of the thoracic aorta. RESULTS: After 6 weeks of CED, blood cholesterol levels were about 80-fold higher, whereas atherosclerosis and cholesterol content in the thoracic aorta were only minimally increased. However, the latter significantly increased within 15 weeks after cholesterol withdrawal, while serum cholesterol level was still 10-fold increased. Thereafter plaque area and cholesterol content remained almost unchanged until the end of the study despite a long-term normalization of serum cholesterol level after withdrawal of CED. Directly after 6 weeks of CED the densities of macrophages and apoptotic cells within plaques were highest, decreasing after cholesterol withdrawal, whereas, vice versa the density of smooth muscle cells (SMCs) significantly increased. CONCLUSION: We suggest that atherosclerotic plaques respond to long-term withdrawal of CED by decrease in number and phenotype of macrophages and increase of SMCs without regression of the lesion size. The cellular changes are suggested to considerably contribute to higher plaque stability.