title: Interfractional Seminal Vesicle Motion Relative to the Prostate Gland for Image-guided Radiotherapy for Prostate Cancer with/without Androgen Deprivation Therapy: A Retrospective Cohort Study.
abstract: We investigated differences in seminal vesicle (SV) length and interfractional SV motion relative to the prostate gland in prostate cancer patients. We compared 32 patients who received androgen deprivation therapy (ADT) before radiotherapy with 12 patients receiving radiotherapy alone at Okayama University Hospital in August 2008-July 2011. We examined the right and left SVs' length and motion by computed tomography (CT) to determine the ADT's effects and analyzed 347 CT scans in a multiple linear regression model. The ADT patients' SV length was significantly shorter than the non-ADT patients'. The differences in right and left SV lengths between the ADT and non-ADT patients were 6.8 mm (95% CI 2.0-11.7 mm) and 7.2 mm (95% CI 3.1- 11.3 mm) respectively in an adjusted regression model. SV motion did not differ between the ADT and non- ADT patients in terms of interfractional motion of the SV tips and the SVs' center relative to the prostate gland. The ADT patients had significantly shorter SVs compared to the non-ADT patients, but no difference in SV motion was observed. SV interfractional motion should thus be compensated using the same planning margins, regardless of whether ADT is used.
authors.affiliation: Department of Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.takahiro.waki1201@gmail.com.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Waki
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Katsui
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Mitsuhashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ogata
authors.forename: Norihisa
authors.initials: N
authors.lastname: Katayama
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Takemoto
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Nasu
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kumon
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D009929:Organ Size / Q000187:drug effects; D011467:Prostate; D011471:Prostatic Neoplasms / Q000473:pathology / Q000628:therapy*; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D012044:Regression Analysis; D012189:Retrospective Studies; D012669:Seminal Vesicles / Q000187:drug effects* / Q000473:pathology*; D014057:Tomography, X-Ray Computed
chemical_list: D000726:Androgen Antagonists
keywords: androgen deprivation therapy; image-guided radiotherapy; prostate cancer; seminal vesicle length; seminal vesicle motion