Delineation of the cardiac sub-structures based on PET-CT in patients with left-sided breast cancer treated with post-operative radiotherapy / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the volume of left ventricle (LV) based on PET-CT in left-sided breast cancer patients treated with adjuvant radiotherapy. To assess the impact of dose and volume in interrelations for heart and cardiac sub-structures using dose-volume histograms. Methods From October 2008 to February 2009, 14 patients with post-operatively confirmed left-sided breast cancer were enrolled in this study. Patients were scanned using contrast enhanced CT for simulation and FDG PET-CT have been applied to display the structure of left ventricle in each patient before radiotherapy (RT). The LV has been delineated based on PET-CT. Other critical sub-structures, such as left anterior descending coronary artery (LAD) have been contoured in each patient. The six-field simple intensity modulated radiotherapy (slMRT)technique has been created in all patients. Results The mean volumes of left ventricle based on PET-CT (LV-PET) were 112. 931 cm3. The volume of LV receiving ≥50% prescription dose highly correlated with the volume of heart receiving ≥50% prescription dose (R = 0. 869, P = 0. 000). There was less correlation between the volume of LAD and the volume of heart receiving ≥ 50% prescription dose ( R = 0. 220, P =0. 440). Conclusions The left ventricle could be delineated efficiently based on imaging of PET-CT. The volume of LV receiving higher dose in RT has high correlation with the volume of heart using sIMRT technique. It may pave the way for further exploring radiation induced cardiac injury in patients with breast cancer.