Myocardial perfusion changes in @entity1 irradiated for XXXX and correlation with coronary artery distribution.

@entity1 @entity453 @entity1007 @entity0
PURPOSE: To evaluate postradiation regional heart perfusion changes with single photon emission tomography (SPECT) myocardial perfusion imaging in 69 @entity1 treated with tangential photon beams radiation therapy (RT) for @entity0 . To correlate SPECT changes with percent irradiated left ventricle (LV) volume and risk factors for @entity453 ( @entity453 ). METHODS AND MATERIALS: Rest SPECT of the LV was acquired pre-RT and at 6-month intervals post-RT. The extent of defects (%) with a severity > 1.5 standard deviations below the mean was quantitatively analyzed for the distributions of the left anterior descending (LAD) artery, left circumflex (LCX) artery, and right coronary artery (RCA) based on computer assisted polar map reconstruction (i.e., bull's-eye-view). Changes in perfusion were correlated with percent irradiated LV receiving > 25 Gy (range 0-32%). Data on @entity1 - and treatment-related factors were collected prospectively (e.g., cardiac premorbidity, risk factors for @entity453 , chemotherapy, and hormonal treatment). RESULTS: In the LAD distribution, there were increased perfusion defects at 6 months (median 11%; interquartile range 2-23) compared with baseline (median 5%; interquartile range 1-14) (p < 0.001). There were no increases in perfusion defects in the LCX or RCA distributions. In multivariate analysis, the SPECT perfusion changes in the LAD distribution at 6 months were independently associated with percent irradiated LV (p < 0.001), hormonal therapy (p = 0.005), and pre-RT @entity1007 (p = 0.006). The SPECT defects in the LAD distribution at 12 and 18 months were not statistically different from those at 6 months. The perfusion defects in the LAD distribution were limited essentially to the regions of irradiated myocardium. CONCLUSION: Tangential photon beam RT in @entity1 with @entity0 was associated with short-term SPECT defects in the vascular distribution corresponding to the radiation portals. Factors related to the extent of perfusion defects included the percent irradiated LV, hormonal treatment, and pre-RT @entity1007 .
