Magnetic resonance imaging of anal cancer: tumor characteristics and early prediction of treatment outcome.

PURPOSE: To analyze tumor characteristics derived from pelvic magnetic resonance imaging (MRI) of patients with squamous cell carcinoma of the anus (SCCA) before and during chemoradiotherapy (CRT), and to compare the changes in these characteristics between scans of responders vs. nonresponders to CRT. METHODS: We included 52 patients with a pelvic 3T MRI scan prior to CRT (baseline scan); 39 of these patients received an additional scan during week 2 of CRT (second scan). Volume, diameter, extramural tumor depth (EMTD), and external anal sphincter infiltration (EASI) of the tumor were assessed. Mean, kurtosis, skewness, standard deviation (SD), and entropy values were extracted from apparent diffusion coefficient (ADC) histograms. The main outcome was locoregional treatment failure. Correlations were evaluated with Wilcoxon's signed rank-sum test and Pearson's correlation coefficient, quantile regression, univariate logistic regression, and area under the ROC curve (AUC) analyses. RESULTS: In isolated analyses of the baseline and second MRI scans, none of the characteristics were associated with outcome. Comparison between the scans showed significant changes in several characteristics: volume, diameter, EMTD, and ADC skewness decreased in the second scan, although the mean ADC increased. Small decreases in volume and diameter were associated with treatment failure, and these variables had the highest AUC values (0.73 and 0.76, respectively) among the analyzed characteristics. CONCLUSION: Changes in tumor volume and diameter in an early scan during CRT could represent easily assessable imaging-based biomarkers to eliminate the need for analysis of more complex MRI characteristics.

Cardiac accumulation of bone marrow mononuclear progenitor cells after intracoronary or intravenous injection in pigs subjected to acute myocardial infarction with subsequent reperfusion.

OBJECTIVE: The purpose of the present study was to compare the efficacy of intracoronary and intravenous injection of autologous progenitor cells for homing to the acutely infarcted but reperfused myocardium in pigs. METHODS: Myocardial infarction was induced in 11 anesthetized pigs by 60-min balloon inflation in the mid LAD. After balloon deflation, reperfusion was verified and autologous CD31(+) progenitor cells, or bone marrow mononuclear cells, labeled with PKH67, were injected either intracoronarily (n=6) or intravenously (n=3). By autopsy, 4-5 days after induction of infarction, tissue from the heart and other organs was obtained for fluorescence microscopy. RESULTS: In the heart, PKH(+) cells were detected throughout the reperfused infarcted myocardium, and the number of PKH(+) cells was significantly higher after intracoronary than after intravenous injection (3.2+/-0.55 vs. 0.33+/-0.17 cells/high-power field/10(6) cells injected, P=.01). Few PKH(+) cells were detected in the spleen, lung, mesenteric lymph node, and bone marrow. In an additional animal with a coil placed in the mid LAD, progenitor cells were not detected in the infarcted myocardium or in the normal myocardium. CONCLUSION: Autologous mononuclear and CD31(+) cells from bone marrow accumulated in the infarcted myocardium when injected intracoronarily or intravenously after established reperfusion, and the accumulation of cells was significantly greater after intracoronary injection than after intravenous injection. Accumulation of PKH(+) cells did not appear in the normal myocardium or in the nonreperfused infarcted myocardium. PKH(+) cells were detected in spleen, lung, and bone marrow but to a lesser degree than in the infarcted myocardium.