title: A Japanese prospective multi-institutional feasibility study on accelerated partial breast irradiation using interstitial brachytherapy: treatment planning and quality assurance.
abstract: BACKGROUND
  In Japan, breast-conserving surgery with closed cavity has generally been performed for breast cancer patients, and accelerated partial breast irradiation (APBI) is considered difficult because Asian females generally have smaller breast sizes than Western females. Therefore, common identification of target and treatment plan method in APBI is required. A prospective multicenter study was conducted in Japan to determine institutional compliance with APBI using high-dose-rate interstitial brachytherapy (ISBT) designed for Japanese female patients.
  
  
  METHODS
  For this study, 46 patients were recruited at eight institutions from January 2009 to December 2011. The reproducibility of the ISBT-APBI plan was evaluated using three criteria: (1) minimum clinical target volume dose with a clip dose ≥ 6 Gy/fraction, (2) irradiated volume constraint of 40-150 cm(3), and (3) uniformity of dose distribution, expressed as the dose non-uniformity ratio (DNR, V150/V100) < 0.35. The ISBT-APBI plan for each patient was considered reproducible when all three criteria were met. When the number of non-reproducible patients was ≤ 4 at study completion, APBI at this institution was considered statistically reproducible.
  
  
  RESULTS
  Half of the patients (52 %) had a small bra size (A/B cup). The mean values of the dose-constrained parameters were as follows: Vref, 117 cm(3) (range, 40-282), DNR, 0.30 (range, 0.22-0.51), and clip dose, 784 cGy (range, 469-3146). A total of 43/46 treatment plans were judged to be compliant and ISBT-APBI was concluded to be reproducible.
  
  
  CONCLUSIONS
  This study showed that multi-institutional ISBT-APBI treatment plan was reproducible for small breast patient with closed cavity.
authors.affiliation: Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suitashi, Osaka, 565-0871, Japan. y.otani@radonc.med.osaka-u.ac.jp.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Otani
authors.affiliation: Department of Radiation Oncology, Nippon Medical School, Tamanagayama Hospital, Tama, Tokyo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nose
authors.affiliation: Department of Radiation Oncology, Kyoundo Hospital, Sasaki-Foundation, Chiyodaku, Tokyo, Japan.
authors.forename: Takushi
authors.initials: T
authors.lastname: Dokiya
authors.affiliation: Department of Breast Oncology, Saitama Medical University, International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Saeki
authors.affiliation: Department of Radiation Oncology, Saitama Medical University, International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kumazaki
authors.affiliation: Department of Surgery, Aidu Chuo Hospital, Aiduwakamatsu, Fukushima, Japan.
authors.forename: Shuuji
authors.initials: S
authors.lastname: Asahi
authors.affiliation: Head of research institute for radiotherapy Southern TOHOKU Research Institute for Neuroscience Southern TOHOKU General Hospital, Koriyama, Fukushima, Japan.
authors.forename: Iwao
authors.initials: I
authors.lastname: Tsukiyama
authors.affiliation: Department of Radiation Oncology, National Hospital Organization Disaster Medical Center, Tachikawa, Tokyo, Japan.
authors.forename: Ichirou
authors.initials: I
authors.lastname: Fukuda
authors.affiliation: Department of Radiology and Radiotherapy, The Jikei University, Daisan Hospital, Komae, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sekine
authors.affiliation: Department of Radiation Oncology, Saitama Medical University, International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Shikama
authors.affiliation: Department of Breast Oncology, Saitama Medical University, International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Radiation Oncology, National Hospital Organization Osaka National Hospital, Osaka, Japan.
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Kotsuma
authors.affiliation: Department of Surgery, Breast Oncology, National Hospital Organization Osaka National Hospital, Osaka, Japan.
authors.forename: Norikazu
authors.initials: N
authors.lastname: Masuda
authors.affiliation: Department of Radiation Oncology, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Eisaku
authors.initials: E
authors.lastname: Yoden
authors.affiliation: Department of General Surgery, Kawasaki Medical School, Kurashiki, Okayama, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Nakashima
authors.affiliation: Department of Radiology, National Hospital Organization Kyushu Medical Center, Fukuoka, Fukuoka, Japan.
authors.forename: Taisei
authors.initials: T
authors.lastname: Matsumura
authors.affiliation: Department of Breast Surgery, National Hospital Organization Kyushu Medical Center, Fukuoka, Fukuoka, Japan.
authors.forename: Shino
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Department of Radiation Oncology, Kyoto City Hospital, Kyoto, Kyoto, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Tachiiri
authors.affiliation: Department of Breast Oncology, Kyoto City Hospital, Kyoto, Kyoto, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Moriguchi
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 Radiation Oncology, Cancer Institute Hospital, the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Oguchi
mesh_terms: D024221:Antineoplastic Protocols / Q000592:standards; D001918:Brachytherapy / Q000379:methods*; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000601:surgery; D002173:Cancer Care Facilities / Q000592:standards*; D003131:Combined Modality Therapy; D005240:Feasibility Studies; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D007564:Japan; D008327:Mammography / Q000379:methods; D015412:Mastectomy, Segmental; D009929:Organ Size; D011446:Prospective Studies; D011785:Quality Assurance, Health Care; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D012016:Reference Values; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed; D018084:Ultrasonography, Interventional