A survey of radiation-induced bronchiolitis obliterans organizing pneumonia syndrome after breast-conserving therapy in Japan.
OBJECTIVE
We observed a rare and unique occurrence of radiation-induced pulmonary injury outside the tangential field for early breast cancer treatment. The findings appeared to be idiopathic and were called radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome. We surveyed major hospitals in Japan to review their findings of radiation-induced BOOP, in particular the clinical and pictorial characteristics of the entity.


METHODS
We reviewed surveys completed and returned by 20 institutions. The survey responses were based on a total of 37 cases of BOOP syndrome. We also reviewed X-ray and computed tomography scans provided by these institutions. We discussed the information derived from the questionnaire and analyzed patients' characteristics, methods used in the treatment of BOOP syndrome, and prognosis.


RESULTS
The incidence of the radiation-induced BOOP syndrome was about 1.8% (37 of 2,056). We did not find a relationship between the characteristics of patients and the occurrence of radiation-induced BOOP syndrome. The pulmonary findings were classified into four patterns on chest computed tomography scans. Progression of the pulmonary lesions observed on chest X-ray was classified into three patterns. Pneumonitis appeared within 6 months after radiotherapy was completed and disappeared within 6-12 months after its onset. At 5-year follow-up, 2 patients had died, 1 of breast cancer and the other of interstitial pneumonitis, which seemed to be idiopathic and unrelated to the radiation-induced BOOP syndrome.


CONCLUSIONS
Although the incidence of BOOP syndrome and its associated prognosis are not significant, the patients' clinical condition must be carefully followed.
Department of Radiology, Kurume University School of Medicine, Kurume, Japan. etsuogo@med.kurume-u.ac.jp
Etsuyo
E
Ogo
Ritsuko
R
Komaki
Kiminori
K
Fujimoto
Masafumi
M
Uchida
Toshi
T
Abe
Katsumasa
K
Nakamura
Michihide
M
Mitsumori
Kenji
K
Sekiguchi
Yuko
Y
Kaneyasu
Naofumi
N
Hayabuchi
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000532:radiotherapy*; D018549:Cryptogenic Organizing Pneumonia / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008168:Lung / Q000000981:diagnostic imaging / Q000528:radiation effects; D008875:Middle Aged; D011379:Prognosis; D011832:Radiation Injuries / Q000150:complications* / Q000000981:diagnostic imaging; D017564:Radiation Pneumonitis / Q000000981:diagnostic imaging / Q000209:etiology*; D014057:Tomography, X-Ray Computed