Analysis of Factors Associated with Radiation-induced Bronchiolitis Obliterans Organizing Pneumonia (BOOP) Syndrome after Breast-conserving Therapy

Purpose/Objective(s)To evaluate factors associated with radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome after breast-conserving therapy.Materials/MethodsThe criteria used for the diagnosis of radiation-induced BOOP syndrome were as follows: (1) radiotherapy to the breast within 12 months; (2) general and/or respiratory symptoms lasting for at least 2 weeks; (3) radiographs showing lung infiltrations outside the radiation port; and (4) no evidence of a specific cause. We retrospectively analyzed 702 women patients with breast cancer who received radiotherapy after breast-conserving surgery at 7 institutions between July 1995 and December 2006 and whose follow-up periods from radiotherapy were more than 12 months. In all patients, the whole breast was irradiated with 2 tangential photon beams. Factors associated with radiation-induced BOOP syndrome were analyzed by logistic regression. Age (<50 or ≥50 years), the side affected, asthma, diabetes, drug allergy, chemotherapy, concurrent chemotherapy, endocrine therapy, concurrent endocrine therapy, radiotherapy method, photon energy (4-6 MV or 10 MV), wedge filter, central lung distance (<3 or ≥3 cm), field length (<20 or ≥20 cm), irradiation to the supraclavicular region, boost to tumor bed, and overall radiotherapy time (<36 or ≥36 days) were evaluated as categorical data.ResultsRadiation-induced BOOP syndrome was seen in 16 patients (2.3%). Multivariate analysis revealed that age (≥50years; p = 0.04) and concurrent endocrine therapy (p = 0.03) were significantly associated with BOOP syndrome. Of the 161 patients whose age was 50 years and older and who received concurrent endocrine therapy, 10 (6.2%) developed BOOP syndrome.ConclusionsAge (≥50 years) and concurrent endocrine therapy can promote the development of radiation-induced BOOP syndrome after breast-conserving therapy. Purpose/Objective(s)To evaluate factors associated with radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome after breast-conserving therapy. To evaluate factors associated with radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome after breast-conserving therapy. Materials/MethodsThe criteria used for the diagnosis of radiation-induced BOOP syndrome were as follows: (1) radiotherapy to the breast within 12 months; (2) general and/or respiratory symptoms lasting for at least 2 weeks; (3) radiographs showing lung infiltrations outside the radiation port; and (4) no evidence of a specific cause. We retrospectively analyzed 702 women patients with breast cancer who received radiotherapy after breast-conserving surgery at 7 institutions between July 1995 and December 2006 and whose follow-up periods from radiotherapy were more than 12 months. In all patients, the whole breast was irradiated with 2 tangential photon beams. Factors associated with radiation-induced BOOP syndrome were analyzed by logistic regression. Age (<50 or ≥50 years), the side affected, asthma, diabetes, drug allergy, chemotherapy, concurrent chemotherapy, endocrine therapy, concurrent endocrine therapy, radiotherapy method, photon energy (4-6 MV or 10 MV), wedge filter, central lung distance (<3 or ≥3 cm), field length (<20 or ≥20 cm), irradiation to the supraclavicular region, boost to tumor bed, and overall radiotherapy time (<36 or ≥36 days) were evaluated as categorical data. The criteria used for the diagnosis of radiation-induced BOOP syndrome were as follows: (1) radiotherapy to the breast within 12 months; (2) general and/or respiratory symptoms lasting for at least 2 weeks; (3) radiographs showing lung infiltrations outside the radiation port; and (4) no evidence of a specific cause. We retrospectively analyzed 702 women patients with breast cancer who received radiotherapy after breast-conserving surgery at 7 institutions between July 1995 and December 2006 and whose follow-up periods from radiotherapy were more than 12 months. In all patients, the whole breast was irradiated with 2 tangential photon beams. Factors associated with radiation-induced BOOP syndrome were analyzed by logistic regression. Age (<50 or ≥50 years), the side affected, asthma, diabetes, drug allergy, chemotherapy, concurrent chemotherapy, endocrine therapy, concurrent endocrine therapy, radiotherapy method, photon energy (4-6 MV or 10 MV), wedge filter, central lung distance (<3 or ≥3 cm), field length (<20 or ≥20 cm), irradiation to the supraclavicular region, boost to tumor bed, and overall radiotherapy time (<36 or ≥36 days) were evaluated as categorical data. ResultsRadiation-induced BOOP syndrome was seen in 16 patients (2.3%). Multivariate analysis revealed that age (≥50years; p = 0.04) and concurrent endocrine therapy (p = 0.03) were significantly associated with BOOP syndrome. Of the 161 patients whose age was 50 years and older and who received concurrent endocrine therapy, 10 (6.2%) developed BOOP syndrome. Radiation-induced BOOP syndrome was seen in 16 patients (2.3%). Multivariate analysis revealed that age (≥50years; p = 0.04) and concurrent endocrine therapy (p = 0.03) were significantly associated with BOOP syndrome. Of the 161 patients whose age was 50 years and older and who received concurrent endocrine therapy, 10 (6.2%) developed BOOP syndrome. ConclusionsAge (≥50 years) and concurrent endocrine therapy can promote the development of radiation-induced BOOP syndrome after breast-conserving therapy. Age (≥50 years) and concurrent endocrine therapy can promote the development of radiation-induced BOOP syndrome after breast-conserving therapy.