Complications from radiotherapy for breast cancer Complicações da radioterapia no câncer de mama

MD. Resident in Radiotherapy, Oncology Center, Hospital Sírio-Libanês, São Paulo, Brazil. MD. Radiation therapy specialist and attending physician, Department of Radiation Oncology, and preceptor of radiotherapy residency, Hospital Sírio-Libanês, São Paulo, Brazil. MD, PhD. Radiation therapy specialist and attending physician, Department of Radiation Oncology, Hospital Sírio-Libanês, São Paulo, Brazil. MD. Radiation therapy specialist and coordinator, Department of Radiation Oncology, Hospital Sírio-Libanês, São Paulo, Brazil. Dear editor, A search through the medical literature discloses relatively little information with a high level of evidence regarding the complications from radiotherapy (RT) for breast cancer. In a single study published in 2001,1 an attempt was made to group all published papers on acute toxicity following breast RT, but the techniques and radiation doses in the studies analyzed by these authors had not been prescribed uniformly. Nevertheless, historically, most published papers used conventional RT and did not use any currently accepted quality control for the treatments prescribed.1 Technological advances in RT have practically eliminated radiodermatitis as a common complication in settings in which the skin does not need to be irradiated, such as treatments for prostate or lung cancer. On the other hand, breast RT still requires caution in this regard, because the skin must be deliberately irradiated. There are lymph vessels communicating between the skin and the breast parenchyma, thus making the skin a target area for treatment. Invariably, therefore, skin symptoms will be present to a certain extent during RT delivery. The incorporation of modern RT into treatments for breast cancer has enabled significant gains in this respect, and the literature shows that there has been a drastic reduction in the incidence of radiodermatitis through the use of this technology, as demonstrated in several randomized studies.2-4 During RT delivery, however, most patients with breast cancer experience acute adverse reactions that are usually not disabling enough to affect their daily activities. Acute skin reactions are most frequently observed in this setting, and itching, skin dryness and erythema with or without desquamation are the most common symptoms. When scaling occurs, it is preferentially located in natural skinfolds, such as the inframammary areas and the axillae. In 10% to 30% of cases, radiodermatitis leads to temporary interruption of treatment delivery,5 which negatively affects our understanding of radiobiology. The main factors correlated with the intensity of radiodermatitis are dose, energy, dose fractionation and technique, breast volume, use of concurrent chemotherapy, appropriateness of self-care and nutritional status of the patient.5 The Radiation Therapy Oncology Group (RTOG) scale6 grades the effects of RT on the skin using the following system: • Grade 0 No reaction • Grade 1 Weak erythema, painless epilation, dry desquamation, decreased sweating and pruritus • Grade 2 Moderate erythema, bright exudative dermatitis in plaques and moderate edema • Grade 3 Exudative dermatitis beyond the skinfolds and intense edema • Grade 4 Ulceration, hemorrhage and necrosis