Portal de Periódicos da CAPES

QUANTEC Guidelines and Predicted Cardiac Mortality Among Breast Cancer Patients

2015; Elsevier BV; Volume: 93; Issue: 3 Linguagem: Inglês

10.1016/j.ijrobp.2015.07.637

1879-355X

James D. Murphy, J. Tinsley Oden, J. Uzan, John P. Einck, Vitali Moiseenko, G. Gagliardi,

Radiation Dose and Imaging

Cardiac morbidity and mortality represents a major concern for women with left-sided breast cancer receiving adjuvant radiation. Substantial research has quantified and studied this risk, and consensus guidelines from QUANTEC recommended keeping the volume of heart receiving 25 Gy (V25) <10% to reduce the risk of cardiac mortality <1%. The purpose of this study was to determine QUANTEC compliance, and to determine whether following QUANTEC guidelines in fact reduces the risk of predicted cardiac mortality to less than 1%. We identified 65 left-sided breast cancer patients from the University of California San Diego treated between 2010 and 2014, and 53 patients from the Karolinska Institutet in Sweden, treated in 2014. We extracted dose-volume histograms (DVHs) from each patient and assessed whether heart V25 was <10% as suggested by QUANTEC. With each DVH we used a normal tissue complication probability (NTCP) model to determine the predicted risk of cardiac-specific mortality. Linear regression was used to determine whether V25 correlated with the NTCP prediction. All patients met the V25 criteria established by QUANTEC. All patients had a predicted risk of cardiac mortality <1%, and the 85 of 118 patients had a risk of <0.1%. The patients with the highest risk of cardiac mortality had V25 that ranged between 2.4 and 4.9%, and the associated risk of cardiac mortality ranged between 0.54 and 0.90%. Patients with higher risk of cardiac mortality had higher V30, V40, and V50. There was little correlation between V25 and predicted cardiac toxicity for the whole study cohort (R2 = 0.90), or when restricting analysis to patients with ≥0.1% risk of cardiac mortality (R2 = 0.76). This study shows that keeping V25 <10% leads to a low predicted risk of cardiac mortality as noted by QUANTEC guidelines. However, V25 alone is insufficient to predict the absolute risk. Future guidelines should use NTCP-based criteria, or specify multiple dosimetric endpoints to maximally reduce the risk of toxicity.