Radiation pneumonitis after breast-conserving surgery for cancer.

Breast-conserving surgery is the most widely used technique in breast cancer treatment. Although it is responsible for the decline in surgical morbidity, its indication in association with radiotherapy can lead to other complications. Radiation pneumonitis is a rare complication (<1% of cases), and its presentation in a non-irradiated area is even rarer. We report the case of a patient with this complication and we comment on its most relevant aspects. The patient is a 60-year-old woman with no history of interest who underwent quadrantectomy for a tumour in the left breast, followed by radiotherapy. The pathology study of the specimen demonstrated an in situ carcinoma with positive hormone receptors. For this reason, prophylactic hormone therapy (exemestane) was indicated. Radiotherapy was applied with a linear accelerator, using a global dose of 50 grays (Gy) and a daily fraction of 200 cGy. The irradiated area was exclusively the left breast, with no axillary or internal mammary chain irradiation. Two months after radiotherapy, the patient came to the Emergency Department due to cough associated with dyspnoea on moderate exertion that had been progressing over the previous two weeks and had not improved with antibiotics or bronchodilators. Upon physical examination, the patient was afebrile, hemodynamically stable and had baseline oxygen saturations of 99%. On auscultation, bilateral (predominantly right) crackles were detected. Chest radiograph revealed a bilateral mid-lower interstitial pattern and bilateral hilar increase (mainly right). Blood work detected no alterations, except for elevated CA 15.3 (131 IU/mL). The study was completed with computed tomography (CT) of the lungs, which showed an area with ground glass pattern located in both hilar regions and in the lingular segment of the left lung, with fibrous tracts (Fig. 1). PET/CT was used to rule out distant disease that might have justified the elevated tumour markers, although no lung uptake images were seen (Fig. 2). The patient had a severe restrictive pattern on spirometry. Bronchoscopy with transbronchial biopsy and bronchoalveolar lavage (BAL) cytology showed fibrosis and inflammatory changes with desquamative pneumonitis, but no observed malignant lesions. The BAL cytology demonstrated elevated neutrophils (38%) and the immunophenotype showed evidence of a high CD4/CD8 ratio (8.3). Given the findings of the biopsies (no lymphangitis carcinomatosa), BAL and PET/CT, we decided to initiate treatment for radiation pneumonitis with steroids at high doses (prednisone 60 mg/day), which obtained a favourable response and improved symptoms. After 4 weeks of treatment, the patient was asymptomatic and c i r e s p . 2 0 1 5 ; 9 3 ( 8 ) : e 9 1 – e 9 3