title: Assessment of transposed ovarian movement: how much of a safety margin should be added during pelvic radiotherapy?
abstract: The purpose of this study was to analyze transposed ovarian movement. Data from 27 patients who underwent ovarian transposition after surgical treatment for uterine cancer were retrospectively analyzed. Computed tomography (CT) images including transposed ovaries were superimposed on other CT images acquired at different times, and were matched on bony structures. Differences in ovarian position between the CT images were measured. The planning organ at risk volume (PRV) margins were calculated from the formula of the 90% reference intervals (RIs) and the 95% RI, which were defined as mean ± 1.65 standard deviation (SD) and mean ± 1.96 SD, respectively. The 90% RI in the cranial, caudal, anterior, posterior, left and right directions were 1.5, 1.5, 1.4, 1.0, 1.7 and 0.9 cm, respectively. The 95% RI in the corresponding directions were 1.5, 2.0, 1.7, 1.2, 1.9 and 1.2 cm, respectively. These data suggest that bilateral ovaries need a PRV margin of ∼2 cm in all directions. The present study suggests that a transposed ovary needs the same PRV margin as a normal ovary (∼2 cm). Even after transposition, ovaries should be kept away from the radiation field to take into consideration the degree of ovarian movement.
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan itaruso@kitasato-u.ac.jp.
authors.forename: Itaru
authors.initials: I
authors.lastname: Soda
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Ishiyama
authors.affiliation: Department of Gynecology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Shigemitsu
authors.initials: S
authors.lastname: Ono
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Takenaka
authors.affiliation: Department of Gynecology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Arai
authors.affiliation: Department of Gynecology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arai
authors.affiliation: Department of Gynecology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Haruko
authors.initials: H
authors.lastname: Iwase
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Sekiguchi
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Kawakami
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Shouko
authors.initials: S
authors.lastname: Komori
authors.affiliation: Department of Gynecology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Onda
authors.affiliation: Department of Radiology and Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minamiku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D000328:Adult; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D009038:Motion; D058958:Organs at Risk / Q000528:radiation effects / Q000601:surgery; D010053:Ovary / Q000000981:diagnostic imaging* / Q000601:surgery*; D010388:Pelvis / Q000528:radiation effects; D011835:Radiation Protection / Q000379:methods*; D011859:Radiography; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014594:Uterine Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*
keywords: cervical cancer; intensity modulation radiotherapy; ovarian preservation; postoperative radiotherapy; radiation therapy; transposed ovary