title: Treatment of thoracic actinomycosis: A retrospective analysis of 40 patients.
abstract: BACKGROUND
  The aim of this study was to evaluate treatment outcomes in patients with thoracic actinomycosis and identify patient characteristics associated with unfavorable responses to antibiotic therapy.
  
  
  METHODS
  A retrospective analysis was performed on 40 patients with pathologically confirmed thoracic actinomycosis.
  
  
  RESULTS
  Initial surgical treatment was performed on 17 patients to control severe symptoms such as hemoptysis or rule out lung cancer. Sixteen (94%) patients were successfully treated, including three patients who did not receive postoperative antibiotics, and one patient died of a postoperative complication. The median duration of oral antibiotic therapy after surgery was 3 months. After the diagnosis of actinomycosis, 23 patients began antibiotic therapy. The median duration of oral antibiotic therapy was 5 months. Favorable treatment outcomes were achieved in 18 of these 23 patients (78%), while five (22%) showed unfavorable responses to antibiotic therapy. Surgery was successfully performed in these five patients. The patients with unfavorable responses to antibiotic therapy had a longer duration of symptoms prior to treatment (median, 10 months) as compared to patients with favorable responses (median, 2 months; P = 0.012).
  
  
  CONCLUSIONS
  Medical treatment failure is possible in patients with thoracic actinomycosis, and close monitoring is necessary in those who begin antibiotic therapy. In addition, surgical resection may be a valid option for patients who do not respond to antibiotic therapy, with the consideration of the age and comorbid conditions.
authors.affiliation: Department of Medicine, Division of Pulmonary and Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae-Uk
authors.initials: JU
authors.lastname: Song
authors.forename: Hye Yun
authors.initials: HY
authors.lastname: Park
authors.forename: Kyeongman
authors.initials: K
authors.lastname: Jeon
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Um
authors.forename: O Jung
authors.initials: OJ
authors.lastname: Kwon
authors.forename: Won-Jung
authors.initials: WJ
authors.lastname: Koh