coronary artery calcium score assessment in breast cancer patients after three-dimensional conformal radiotherapy: is calcium score an appropriate screening study?

Background: adjuvant radiation therapy (rt) improves the prognosis of breast cancer (bc); nevertheless, causes post-rt complications. oneof themostlife-threatening complications of rt inbcpatients is atherosclerotic coronary artery disease (cad).compared with old two-dimensional rt (2d-rt), newer three-dimensional conformal radiotherapy (3d-crt) protects normal tissues including the heart from irradiation. early detection of plaques using coronary artery calcium score (cacs) could improve the post-rt bc survivors’ outcomes. objectives: this study assessed cacs in bc patients who underwent 3d-crt to find whether there is any significant difference between their cacs and those of non-bc patients. patients and methods: cacs of fifty bc patients with different intervals from rt - case - and fifty women with no history of bc or rt - control - using 64-slice ecg-gated ct scan were assessed as agatston score (as). the risk factors of cad, the framingham’s 10-year risk score, and the age-matched cacs percentiles were evaluated. results: no as difference between the case and control was found. no correlation between as and rt-to-follow-up time interval, laterality of bc, framingham’s 10-year risk score or traditional cad risk factors were detected. increase in cacs related to the senile atherosclerotic process was shown (p < 0.001). conclusion: no significant difference in cacs was found in bc patients treated by 3d-crt in comparison with those of non-bc individuals or bc patients who treated by 2d-rt. this finding may be the result of either the non-calcified nature of radiationinduced cad plaques or reduced cardiac radiation in 3d-crt, leading to myocardial microvascular disease rather than senile calcified atherosclerotic plaques. cacs may not be an appropriate screening test to detect early cad in these patients.