title: Simulation analysis of optimized brachytherapy for uterine cervical cancer: Can we select the best brachytherapy modality depending on tumor size?
abstract: OBJECTIVE
  To choose the optimal brachytherapeutic modality for uterine cervical cancer, we performed simulation analysis.
  
  
  METHODS
  For each high-risk clinical target volume (HR CTV), we compared four modalities [classical conventional intracavitary brachytherapy (ConvICBT), Image-guided ICBT (IGICBT), intracavitary/interstitial brachytherapy (ICISBT), and interstitial brachytherapy (ISBT) with perineal approach] using dose-volume histograms using eight sizes of HR CTV (2 × 2 × 2 cm to 7 × 4 × 4 cm) and organs at risk model.
  
  
  RESULTS
  In ConvICBT, the doses covered 90% of the HR CTV [D90(HR CTV)] decreased from 197% prescribed dose (PD) for the HR CTV size (2 × 2 × 2 cm) to 73% PD for 5 × 4 × 4 cm, whereas the other three modalities could achieve 100% PD for all HR CTV sizes. The minimum doses received by the maximally irradiated 2-cm(3) volumes for organs at risks of IGICBT demonstrated lower values than those of ConvICBT for the HR CTV size of 4 × 3 × 3 cm or smaller. ICISBT demonstrated lower values than those of IGICBT for 4 × 3 × 3 cm or larger. ISBT demonstrated lowest values for 5 × 4 × 4 cm or larger.
  
  
  CONCLUSIONS
  HR CTV size of 4 × 3 × 3 cm seems to be a threshold volume in this simulation analysis, and IGICBT is a better choice for smaller HR CTV than the threshold volume. On larger HR CTV, ICISBT or ISBT is the better choice.
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Takatsuki, Osaka, Japan. Electronic address: rad113@poh.osaka-med.ac.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan.
authors.forename: Hideya
authors.initials: H
authors.lastname: Yamazaki
authors.affiliation: Department of Radiation Oncology, National Hospital Organization Osaka National Hospital, Osaka, Osaka, Japan.
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Kotsuma
authors.affiliation: Department of Radiology, National Hospital Organization Himeji Medical Center, Himeji, Hyogo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Takenaka
authors.affiliation: Department of Radiology, National Hospital Organization Osaka National Hospital, Osaka, Osaka, Japan.
authors.forename: Mari Mikami
authors.initials: MM
authors.lastname: Ueda
authors.affiliation: Department of Radiology, National Hospital Organization Osaka National Hospital, Osaka, Osaka, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Miyake
authors.affiliation: Department of Radiology, National Hospital Organization Osaka National Hospital, Osaka, Osaka, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tsujimoto
authors.affiliation: Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Masui
authors.affiliation: Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.affiliation: Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Iori
authors.initials: I
authors.lastname: Sumida
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Uesugi
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Taiju
authors.initials: T
authors.lastname: Shimbo
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Yoshikawa
authors.affiliation: Department of Radiation Oncology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Yoshioka
authors.affiliation: Department of Radiation Oncology, National Hospital Organization Osaka National Hospital, Osaka, Osaka, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tanaka
authors.affiliation: Department of Radiology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Narumi
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008962:Models, Theoretical; D058958:Organs at Risk; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D061089:Radiotherapy, Image-Guided / Q000379:methods; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000473:pathology* / Q000532:radiotherapy*
keywords: Brachytherapy; Dose-volume histograms; Simulation analysis; Uterine cervical cancer