title: Incidence and severity of adverse events associated with re-irradiation for spine or pelvic bone metastases.
abstract: BACKGROUND
  Adverse events associated with re-irradiation for painful bone metastases have not been adequately evaluated. The purpose of this study was to clarify the incidence and severity of adverse events associated with re-irradiation for spine or pelvic bone metastases.
  
  
  METHODS
  Data for 61 consecutive patients who required re-irradiation for spine or pelvic bone metastases between April 2009 and March 2013 were retrospectively evaluated in this study. The adverse events, biologically effective dose (BED), and the responses to pain and/or symptoms caused by cord compression were evaluated.
  
  
  RESULTS
  Of the 61 patients, 52 were included in the study and their data were analyzed. The site of re-irradiation was the spine in 35 patients (67 %), and the pelvic bone in the remaining 17 patients (33 %). The median follow-up period was 170 days (range 5-1,644 days) for all eligible patients. The median interval from initial radiation therapy to re-irradiation was 161 days (range 26-2,909 days). The median cumulative BED from the initial radiation and re-irradiation was 115 Gy (range 80-155 Gy2). The acute adverse events were all below grade 2 in severity, except for two patients who showed grade 3 pain flare within a few days after the start of re-irradiation. No late adverse events were observed in this study that were grade 3 or of worse severity.
  
  
  CONCLUSIONS
  The incidence and severity of adverse events after re-irradiation for spine or pelvic bone metastases were within acceptable limits in this study.
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan. yahirano@east.ncc.go.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hirano
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakamura
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Sadamoto
authors.initials: S
authors.lastname: Zenda
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Hojo
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Motegi
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Arahira
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Toshima
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Onozawa
authors.affiliation: Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Akimoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000150:complications / Q000532:radiotherapy* / Q000556:secondary; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D010384:Pelvic Bones; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D000069475:Re-Irradiation / Q000009:adverse effects*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013131:Spine
keywords: Bone metastases; Myelitis; Re-irradiation; Spine