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

Veerle A. B. van den Bogaard, Bastiaan D. P. Ta, Arjen van der Schaaf, Angelique B. Bouma, Astrid M. H. Middag, Enja J. Bantema-Joppe, Lisanne V. van Dijk, Femke B. J. van Dijk-Peters, Laurens A. W. Marteijn, Gertruida H. de Bock, Johannes G. M. Burgerhof, Jourik A. Gietema, Johannes A. Langendijk, John H. Maduro, Anne P. G. Crijns*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

160 Citaten (Scopus)
424 Downloads (Pure)

Samenvatting

Purpose

A 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 Methods

The 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.

Results

The 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).

Conclusion

A 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.

Originele taal-2English
Pagina's (van-tot)1171-1178
Aantal pagina's8
TijdschriftJournal of clinical oncology : official journal of the American Society of Clinical Oncology
Volume35
Nummer van het tijdschrift11
DOI's
StatusPublished - 10-apr-2017

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