[Radiation pneumonitis in the treatment of early-stage breast cancer].

Despite of improvement of radiotherapy techniques and increasing usage of conformal radiation therapy which provides decrease of dose for normal tissues and organs, cases of radiation-induced injuries are still registrated. The aim of this study is to determine frequency and severity of lung toxicity in 513 breast cancer patients with Tis-2N0-2M0 disease after breast conserving surgery and chemotherapy depending from radiation therapy technique and irradiation volume. It is quite clear that in breast cancer patients frequency of lung toxicity after breast conserving surgery and RT increases from 20-24% when irradiating only breast to 37-41% when irradiating breast and regional lymph nodes. In our analysis the frequency of lung toxicity was quite similar for 2D conventional therapy (27,4%) and for 3D conformal therapy (28,7%). The risk of developing radiation pneumonitis increases dramatically with extension of V20 for ipsilateral lung more than 30%, mean lung dose more than 18 Gy, in patients with initial small volume of the lung (less than 110 cm3).