Dose Distribution in the Heart and Cardiac Chambers following 4-field Radiation Therapy of Breast Cancer: a Retrospective Study

Abstract

Purpose:To evaluate cardiac doses in breast cancer patients with stage II/III treated with 4-field radiotherapy based on computed tomography (CT) dose planning.Methods and Materials:Based on archived CT images, whole heart and cardiac chamber radiation doses were analyzed in 216 (111 left-sided and 105 right-sided) mastectomized or lumpectomized breast cancer patients treated at a single institution, the Norwegian Radium Hospital, between 2000–2002. Individual dose volume histograms for the whole heart and for the four cardiac chambers were obtained, and mean, median and maximum doses to these structures were calculated. The dose (Gy) delivered to the 5% of the volume of each cardiac structure (D5%), and the volume percentage of each structure receiving ≥ 25 Gy (V25Gy) were reported. Normal tissue complication probability (NTCP) calculations were used to estimate the risk for ischemic heart disease (IHD).Results:Cohort-based medians of the whole heart mean dose (Dmean) for left- and right-sided tumors were 3.2 Gy and 1.3 Gy, respectively, with similar ventricular but lower atrial values. The atrial doses did not differ according to laterality of the breast tumor. In 13 patients with left-sided cancer, 5% of the heart volume was exposed to >25 Gy. The NTCP estimates were generelly low, with a maximum of 2.8%.Conclusions:During adjuvant CT-based locoregional radiotherapy of women with breast cancer, the cardiac radiation doses are, at the group level, below recommended threshold values (D5% < 25 Gy), though individual patients with left-sided disease may exceed these limits.

Coronary calcium score in 12-year breast cancer survivors after adjuvant radiotherapy with low to moderate heart exposure – Relationship to cardiac radiation dose and cardiovascular risk factors

“…For the 106 patients in our cohort where detailed dosimetric data were available, the median value for the mean cardiac dose was 3.0 Gy (left-sided BC), and 1.5 Gy (right-sided BC), considerably lower than in other populations studied [9,14,15]. Taylor et al demonstrated a higher cardiac mortality rate with older, as compared to more recent, radiation techniques [15].…”

“…The breast/chest wall received a total dose of 50 Gy given in 25 fractions over five weeks. After breast conserving surgery, women below the age of 50 received an electron boost of 10-16 Gy to the tumour bed (6)(7)(8)(9)(10)(11)(12). After mastectomy, all stage III patients and women with stage II with positive resection margins were given a bolus covering the chest wall, the remaining patients received a bolus covering the mastectomy scar with a 3 cm margin.…”

“…After mastectomy, all stage III patients and women with stage II with positive resection margins were given a bolus covering the chest wall, the remaining patients received a bolus covering the mastectomy scar with a 3 cm margin. For 106 patients treated after year 2000, mean, median and maximum doses as well as D5% for the whole heart and each specific chamber were recorded as described [9].…”

Risk of Heart Failure With Preserved Ejection Fraction in Older Women After Contemporary Radiotherapy for Breast Cancer

“…As the cardiac chambers exposed to radiation may vary by tumor side, we also matched by tumor side. 14, 15 Controls were required to have follow-up (index interval) equivalent to or greater than the time from radiotherapy to HF diagnosis of the corresponding case.…”

État de l’art de l’irradiation des ganglions de la chaîne mammaire interne

“…Gagliardi et al, dans leur modèle prédictif de la toxicité cardiaque basé sur une population de 809 patientes traitées pour un cancer du sein, ont exprimé que lorsque le volume de coeur recevant une dose supérieure à 25 Gy (V 25Gy ) restait inférieur à 10 %, la probabilité de mortalité cardiaque 15 ans après la radiothérapie était de moins de 1 % [34,35]. Des recommandations en ont été déduites, comme par le groupe national norvégien du cancer du sein, qui a préconisé un V 25Gy cardiaque de moins de 5 %, ou le groupe danois un V 40Gy (volume recevant 40 Gy) de moins de 5 % et un V 20Gy (volume recevant 20 Gy) de moins de 10 % [36]. Ces valeurs ne sont cependant pas extrapolables à tous les centres car elles dépendent fortement de la technique standard locale d'irradiation.…”