title: Nationwide multi-institutional retrospective analysis of high-dose-rate brachytherapy combined with external beam radiotherapy for localized prostate cancer: An Asian Prostate HDR-BT Consortium.
abstract: To report outcomes and risk factors of high-dose-rate (HDR) brachytherapy combined with external beam radiotherapy with or without androgen deprivation therapy (ADT) in prostate cancer patients.
  
  
  
  This multi-institutional retrospective analysis comprised 3424 patients with localized prostate cancer at 16 Asian hospitals. One-thirds (27.7%) of patients received only neoadjuvant ADT, whereas almost half (49.5%) of patients received both neoadjuvant and adjuvant ADT. Mean duration of neoadjuvant and adjuvant ADT were 8.6 months and 27.9 months, respectively. Biochemical failure was defined by Phoenix ASTRO consensus. Biochemical control rate, clinical disease-free survival (cDFS), cause-specific survival, and overall survival (OS) were calculated.
  
  
  
  Median followup was 66 months. Ten-year biochemical control, cDFS, cause-specific survival, and OS rate were 81.4%, 81.0%, 97.2%, and 85.6%, respectively. Receiving both neoadjuvant and adjuvant ADT was detected as a favorable factor for biochemical control, cDFS, and OS, but pelvic irradiation was detected as an adverse factor for cause-specific survival, and OS. Ten-year cumulative rates of late Grade ≥2 genitourinary and gastrointestinal toxicities were 26.8% and 4.1%, respectively; receiving both neoadjuvant and adjuvant ADT was detected as a favorable factor for preventing both toxicities.
  
  
  
  HDR combined with external beam radiotherapy was an effective and safe treatment for localized prostate cancer. Combination of long-term ADT was suggested to be necessary, even for HDR brachytherapy, and was useful in suppressing late toxicities. Meanwhile, pelvic irradiation was suggested to have an adverse effect on OS of our study population.
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, Kanagawa, Japan. Electronic address: hishiyam@kitasato-u.ac.jp.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Ishiyama
authors.affiliation: Department of Radiology, Kawasaki Medical School, Okayama, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Kamitani
authors.affiliation: Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma, Japan.
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Kawamura
authors.affiliation: Department of Radiation Oncology, Saitama Medical University International Medical Center, Saitama, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Kato
authors.affiliation: Department of Radiology, The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Aoki
authors.affiliation: Department of Diagnostic Radiology and Radiation Oncology, Kochi Medical School, Kochi, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kariya
authors.affiliation: Departments of Radiology, National Hospital Organization, National Kyushu Medical Center, Fukuoka, Japan.
authors.forename: Taisei
authors.initials: T
authors.lastname: Matsumura
authors.affiliation: Department of Radiology and Radiation Oncology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Kaidu
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Osaka, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Radiation Oncology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Yaichiro
authors.initials: Y
authors.lastname: Hashimoto
authors.affiliation: Department of Radiation Oncology, Wakayama Medical University, Wakayama, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Noda
authors.affiliation: Department of Radiation Oncology, National University Cancer Institute, Singapore.
authors.forename: Keith H C
authors.initials: KHC
authors.lastname: Lim
authors.affiliation: Department of Radiation Oncology, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Kawase
authors.affiliation: Department of Radiation Oncology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Inaba
authors.affiliation: Department of Radiotherapy, Graduate School of Medical Science, Kanazawa University, Ishikawa, Japan.
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Kumano
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Osaka, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Yoshikawa
authors.affiliation: Department of Radiation Oncology, Osaka University School of Medicine, Osaka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.affiliation: Department of Radiation Oncology, Hamamatsu University School of Medicine, Shizuoka, Japan.
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Radiology, Kawasaki Medical School, Okayama, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Hiratsuka
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Itami
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D001918:Brachytherapy / Q000009:adverse effects; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D005767:Gastrointestinal Diseases / Q000209:etiology; D006801:Humans; D007564:Japan; D008297:Male; D052801:Male Urogenital Diseases / Q000209:etiology; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000628:therapy*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen
keywords: Androgen deprivation therapy; Brachytherapy; High dose rate; Prostate cancer; Whole pelvic irradiation