Bronchiolitis obliterans organizing pneumonia after stereotactic ablative radiation therapy for lung cancer: A case report.

Bronchiolitis obliterans organizing pneumonia is an interstitial lung disease rarely occurring after radiotherapy probably due to an activation of autoimmune processes. Most cases have been described after postoperative radiotherapy for breast cancer. Corticosteroids represent the main treatment, prognosis is generally favorable. We described a case of bronchiolitis obliterans organizing pneumonia after stereotactic ablative radiation therapy for a recurrent lung cancer. Antibiotics and steroids were administered to solve the clinical picture. After three years, a new lesion at the right lung was found and treated with stereotactic ablative radiation therapy and concomitant long course of steroids with no recurrence of bronchiolitis obliterans organizing pneumonia. Bronchiolitis obliterans organizing pneumonia is a rare event after radiotherapy with undefined risk factors. In our case, steroids played an important role in management and, maybe, in preventing bronchiolitis obliterans organizing pneumonia recurrence after second course of stereotactic ablative radiation therapy.

[Radiation-induced bronchiolitis obliterans with organizing pneumonia]. / Complications pulmonaires de la radiothérapie après cancer du sein : penser à la BOOP.

Bronchiolitis obliterans with organizing pneumonia is an inflammatory reaction that can occur as a consequence of various pulmonary affections. Radiotherapy is not the sole and systematic cause of bronchiolitis obliterans with organizing pneumonia. Radiation-induced should not be confused with post-radiation, dose-dependent, inflammatory pulmonary fibrosis, which is non-immunological and located within the irradiation field. The role of immunity, local inflammation and individual radiosensitivity in bronchiolitis obliterans with organizing pneumonia is not well defined. Bronchiolitis obliterans with organizing pneumonia represents 1% of irradiated patients with breast cancer. It results in fever (flu-like symptoms), a rather dry cough and dyspnea. In the post-radiation context, bronchiolitis obliterans with organizing pneumonia may be diagnosed several months and up to a year after breast irradiation. The treatment consists of prolonged steroids or immunosuppressants, which do not prevent chronicity in 15% of patients and death in up to 5% of cases, the remaining 80% of patients healing without sequelae.

[Cryptogenic organizing pneumonia]. / Pneumopathie organisée cryptogénique.

INTRODUCTION: Organizing pneumonia is a particular type of inflammatory reaction of the lung which gives rise to a clinico-pathological syndrome. It is called "secondary" when a cause such as an infection, a drug toxicity, or a connective tissue disease can be identified, or "cryptogenic" when no cause is identified. The clinical picture is usually characterized by the subacute onset of fever, fatigue, cough and dyspnea, with multiple subpleural areas of consolidation on thoracic imaging. STATE OF THE ART: Organizing pneumonia is characterised by the presence of buds of endoalveolar connective tissue. These result from an injury to the alveolar epithelium, followed by the deposition of fibrin in the alveolar spaces, and the migration of fibroblasts which produce a myxoid endoalveolar matrix. A remarkable feature of organizing pneumonia is the complete disappearance of these endoalveolar buds with corticosteroid treatment, in sharp contrast with what is seen in pulmonary fibrosis. The clinical response to corticosteroids is usually prompt and excellent. Relapses are frequent but usually benign. PERSPECTIVES AND CONCLUSION: As the clinical, imaging and pathological characteristics of organizing pneumonia are now well established, many questions remain unanswered, such as the mechanisms involved in the complete reversibility of the pulmonary lesions, and the role of steroid-sparing treatments such as immunomodulatory macrolides.