title: Pulmonary metastases after low-dose-rate brachytherapy for localized prostate cancer.
abstract: OBJECTIVE
  To analyze unusual events and focus discussion on pulmonary metastasis in particular after low-dose-rate brachytherapy (LDR-BT) for prostate cancer (PCa).
  
  
  METHODS
  A total of 616 consecutive patients who had undergone LDR-BT for clinically localized PCa at Jikei University Hospital between October 2003 and April 2010 were enrolled in this study. Follow-up information was summarized, and patterns of biochemical recurrence and clinical outcome were investigated.
  
  
  RESULTS
  Disease risk was stratified as low-risk in 231 patients, intermediate-risk in 365, and high-risk in 20, respectively. Of these patients, 269 (43.7%) had received hormonal therapy (HT) in combination with LDR-BT, and 80 (13.0%) had received external beam radiotherapy (EBRT). Average dosimetric parameter values with and without EBRT were 95.3% and 94.2% for V100, 132.8 Gy and 164.2 Gy for D90, and 180.6 Gy2 and 173.7 Gy2 for the biologically effective dose. Biochemical recurrence was noted in 14 patients (6.1%) in the low-risk group, 25 patients (6.8%) in the intermediate-risk group, and 6 patients (30.0%) in the high-risk group, respectively. In these cases of biochemical recurrence, 9 (64.3%), 13 (52.0%), and 4 patients (66.7%) in each respective risk group showed signs of clinical recurrence. Five patients (19.2%) with clinical recurrence developed pulmonary metastases, of which 4 were isolated lesions. All tumors responded favorably to subsequent HT.
  
  
  CONCLUSIONS
  LDR-BT for biologically aggressive PCa may be linked to possible pulmonary metastasis owing to tumor dissemination during seed implantation. This information is important in planning adequate treatment for these patients.
authors.affiliation: Department of Urology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Kido
authors.affiliation: Department of Urology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kuruma
authors.affiliation: Department of Urology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sasaki
authors.affiliation: Department of Urology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Miki
authors.affiliation: Department of Radiation Oncology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Aoki
authors.affiliation: Department of Urology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Pathology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahash
authors.affiliation: Department of Radiation Oncology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kanehira
authors.affiliation: Department of Urology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Egawa
keywords: Brachytherapy; Neoplasm metastasis; Prostate neoplasms