TY - JOUR
T1 - Validation and Modification of a Prediction Model for Acute Cardiac Events in Patients With Breast Cancer Treated With Radiotherapy Based on Three-Dimensional Dose Distributions to Cardiac Substructures
AU - van den Bogaard, Veerle A. B.
AU - Ta, Bastiaan D. P.
AU - van der Schaaf, Arjen
AU - Bouma, Angelique B.
AU - Middag, Astrid M. H.
AU - Bantema-Joppe, Enja J.
AU - van Dijk, Lisanne V.
AU - van Dijk-Peters, Femke B. J.
AU - Marteijn, Laurens A. W.
AU - de Bock, Gertruida H.
AU - Burgerhof, Johannes G. M.
AU - Gietema, Jourik A.
AU - Langendijk, Johannes A.
AU - Maduro, John H.
AU - Crijns, Anne P. G.
PY - 2017/4/10
Y1 - 2017/4/10
N2 - PurposeA relationship between mean heart dose (MHD) and acute coronary event (ACE) rate was reported in a study of patients with breast cancer (BC). The main objective of our cohort study was to validate this relationship and investigate if other dose-distribution parameters are better predictors for ACEs than MHD.Patients and MethodsThe cohort consisted of 910 consecutive female patients with BC treated with radiotherapy (RT) after breast-conserving surgery. The primary end point was cumulative incidence of ACEs within 9 years of follow-up. Both MHD and various dose-distribution parameters of the cardiac substructures were collected from three-dimensional computed tomography planning data.ResultsThe median MHD was 2.37 Gy (range, 0.51 to 15.25 Gy). The median follow-up time was 7.6 years (range, 0.1 to 10.1 years), during which 30 patients experienced an ACE. The cumulative incidence of ACE increased by 16.5% per Gy (95% CI, 0.6 to 35.0; P = .042). Analysis showed that the volume of the left ventricle receiving 5 Gy (LV-V5) was the most important prognostic dose-volume parameter. The most optimal multivariable normal tissue complication probability model for ACEs consisted of LV-V5, age, and weighted ACE risk score per patient (c-statistic, 0.83; 95% CI, 0.75 to 0.91).ConclusionA significant dose-effect relationship was found for ACEs within 9 years after RT. Using MHD, the relative increase per Gy was similar to that reported in the previous study. In addition, LV-V5 seemed to be a better predictor for ACEs than MHD. This study confirms the importance of reducing exposure of the heart to radiation to avoid excess risk of ACEs after radiotherapy for BC. (C) 2017 by American Society of Clinical Oncology.
AB - PurposeA relationship between mean heart dose (MHD) and acute coronary event (ACE) rate was reported in a study of patients with breast cancer (BC). The main objective of our cohort study was to validate this relationship and investigate if other dose-distribution parameters are better predictors for ACEs than MHD.Patients and MethodsThe cohort consisted of 910 consecutive female patients with BC treated with radiotherapy (RT) after breast-conserving surgery. The primary end point was cumulative incidence of ACEs within 9 years of follow-up. Both MHD and various dose-distribution parameters of the cardiac substructures were collected from three-dimensional computed tomography planning data.ResultsThe median MHD was 2.37 Gy (range, 0.51 to 15.25 Gy). The median follow-up time was 7.6 years (range, 0.1 to 10.1 years), during which 30 patients experienced an ACE. The cumulative incidence of ACE increased by 16.5% per Gy (95% CI, 0.6 to 35.0; P = .042). Analysis showed that the volume of the left ventricle receiving 5 Gy (LV-V5) was the most important prognostic dose-volume parameter. The most optimal multivariable normal tissue complication probability model for ACEs consisted of LV-V5, age, and weighted ACE risk score per patient (c-statistic, 0.83; 95% CI, 0.75 to 0.91).ConclusionA significant dose-effect relationship was found for ACEs within 9 years after RT. Using MHD, the relative increase per Gy was similar to that reported in the previous study. In addition, LV-V5 seemed to be a better predictor for ACEs than MHD. This study confirms the importance of reducing exposure of the heart to radiation to avoid excess risk of ACEs after radiotherapy for BC. (C) 2017 by American Society of Clinical Oncology.
KW - RADIATION-THERAPY
KW - HEART-DISEASE
KW - CORONARY-ARTERY
KW - PROSPECTIVE COHORT
KW - MORTALITY
KW - RISK
KW - DIAGNOSIS
KW - VOLUME
KW - ATLAS
KW - LUNG
U2 - 10.1200/JCO.2016.69.8480
DO - 10.1200/JCO.2016.69.8480
M3 - Article
C2 - 28095159
SN - 0732-183X
VL - 35
SP - 1171
EP - 1178
JO - Journal of clinical oncology : official journal of the American Society of Clinical Oncology
JF - Journal of clinical oncology : official journal of the American Society of Clinical Oncology
IS - 11
ER -