HR-CT evaluation of lung parenchymal alterations in patients following breast conservation therapy

Twenty patients with early-stage breast cancer treated with breast conservation surgery and definite radiation, underwent computed tomography (added HR-CT) of the lungs before, immediately after, and at one, six, and twelve months after radiotherapy. During the follow-up period, 17 (85%) of the patients developed parenchymal alterations in the irradiated lung volume. We classified the parenchymal alterations into seven patterns: pattern 1 = septal line, 2 = nodular opacity, 3 = ground-glass opacity, 4 = consolidation, 5 = curvilinear opacity, 6 = aircyst accumulation, and 7 = irregularity of pleural surface. From one to six months after radiotherapy, 14 patients developed nodular opacities and ground glass opacities in the irradiated lung field. At 12 months after radiotherapy, fourteen patients were found to have aircyst accumulation and irregularity of the pleural surface. In this study, none of the patients presented any abnormal findings immediately after irradiation. There was no relationship between central lung distance or boost irradiation and the parenchymal alterations in the lung. On the other hand, there was a close relationship between oral anti-cancer agents and lung lesions. In conclusion, HR-CT was useful to evaluate morphologic changes in the irradiated lung.