radiation pneumonitis
Medical term for inflammation of the lungs caused by radiation therapy, typically for thoracic cancers.
Radiation pneumonitis can develop after radiotherapy for breast cancer.
Compound of 放射性 (ほうしゃせい, 'radioactive') + 肺炎 (はいえん, 'pneumonia'). The term is a direct medical borrowing from English 'radiation pneumonitis'.