Helical tomotherapy for patients presented with implant breast reconstruction in case of adjuvant breast cancer radiotherapy: A single center experience

Do We Need to Delineate the Humeral Head in Breast Cancer Patients?

Humeral heads can be unintentionally exposed during breast radiotherapy, particularly when regional lymph nodes are targeted. Moreover, rotational intensity-modulated radiation therapy techniques, such as helical tomotherapy (HT), increase the low-dose bath, the consequences of which are subject to debate. The aim of this study was to analyze late adverse events involving humeral heads occurring after adjuvant locoregional breast radiotherapy with HT. This single-center retrospective study included 159 breast cancer patients locoregionally irradiated, including the regional lymph nodes, in an adjuvant setting with HT at Institut Curie (Paris, France), between January 2010 and 2016. After a median delay of 48 months, six patients (3.8%) developed localized bone pain, three (1.9%) developed a shoulder functional limitation and one (0.6%) developed a traumatic humeral head fracture. The average mean and maximum doses to humeral heads were 9.18 Gy and 24.41 Gy, respectively, and were not statistically associated with humeral head adverse events. Adverse events were statistically more frequent after mastectomy than after breast-conserving surgery. Berg's level 1 and 2/3 irradiation, and right-sided radiotherapy were associated with an increased maximum dose. In summary, clinical adverse events were rare, and radiation exposure to humeral heads was low. No correlation was found between dosimetric parameters and late toxicity.

Cardiotoxicity in breast cancer patients treated with radiation therapy: From evidences to controversies

Radiation therapy has a prime importance for breast cancer management. However, first-generation techniques delivered significant radiation dose to the heart, which substantially increased cardiac mortality. Breast radiation therapy has fortunately evolved, and state-of-the-art radiation therapy techniques currently efficiently spare the heart without altering local control or overall survival. However, at the present time, potential cardiotoxicity risk is still a matter of concern and controversies exist concerning how to precisely evaluate cardiac radiation exposure, how to predict radiation-induced cardiac adverse events and which dosimetric constraints are clinically relevant. Based on current literature, this paper aims to review the present understanding of cardiotoxicity associated with breast cancer irradiation and to discuss controversies and perspectives about cardiac sparing improvement.