Anterior Myocardial Territory May Replace the Heart as Organ at Risk in Intensity-Modulated Radiotherapy for Left-Sided Breast Cancer

Intensity modulated radiation therapy with simultaneous integrated boost in early breast cancer irradiation. Report of feasibility and preliminary toxicity

“…Tan et al proposed an analysis with 23 patients, affected by left-sided breast cancer, planned with five IMRT plans per patient (with different optimization criteria for heart sparing) [30]. Mean dose to heart, as averaged over 23 patients, varied over the five groups of plansdistinguished by heart optimization criteria -from 8.8 ± 3.7 Gy to 11.1 ± 3.9 Gy.…”

“…Résultats. -Le suivi a été en médiane de 28 mois (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). La toxicité cutanée aiguë a été de grade 0 chez huit patientes (7 %), 1 chez 80 (72 %), 2 chez 24 (21 %) et 3 chez aucune.…”

Sparing Functional Anatomical Structures During Intensity-Modulated Radiotherapy: An Old Problem, A New Solution

“…The development and refinement of RT techniques and systemic drugs has reduced the incidence of radiation-related cardiac toxicities [53]. Given the anatomical and physical features relevant to RT of breast cancer and Hodgkin's lymphoma, the anterior rim of the heart will inevitably receive a higher dose of radiation than other parts of the heart and should correspondingly be considered more carefully [4,59]. Tan et al suggested that the anterior myocardial territory can replace the heart as an independent OAR [4].…”

“…Given the anatomical and physical features relevant to RT of breast cancer and Hodgkin's lymphoma, the anterior rim of the heart will inevitably receive a higher dose of radiation than other parts of the heart and should correspondingly be considered more carefully [4,59]. Tan et al suggested that the anterior myocardial territory can replace the heart as an independent OAR [4]. The anterior myocardial territory includes the anterior myocardium and coronary arteries in the anterior cardiac portion, such as the left and right main coronary arteries, left anterior descending artery, left circumflex artery and right marginal artery.…”

“…The conventional dose-volume histogram and/or normal tissue complication probability models are inadequate for predicting RT response since they do not take this functional and structural heterogeneity into account [1]. With a growing understanding of these heterogeneities within the OAR, an increasing number of functional structures have been investigated [2][3][4][5], raising the possibility of functional structure-sparing RT. However, both the definition of target volume and the OAR may affect the design and implementation of RT planning [6].…”