title: Relationship between prostate volume changes and treatment duration of neoadjuvant androgen deprivation during intensity-modulated radiation therapy for Japanese patients with prostate cancer.
abstract: The application of neoadjuvant androgen deprivation (NAD) in prostate cancer leads to a reduction in prostate volume, and the trends in volume reduction differ according to the treatment duration of NAD. A reduction in volume during external beam radiation therapy may lead to the exposure of normal tissues to an unexpected dose. In fact, prostate volume reductions have primarily been reported in European and American institutions. Although the prostate volume of Japanese patients is known to be small, the trends in prostate volume change during radiation therapy remain unclear. In the present study, we aimed to evaluate the changes in prostate volume of Japanese patients during intensity-modulated radiation therapy (IMRT) with NAD. Nineteen Japanese patients with prostate cancer underwent IMRT with NAD. Kilovoltage computed tomography (CT) images were obtained for treatment planning and verification of the treatment position for each treatment fraction. The patients were divided into 3 groups based on the duration of NAD, as follows: NAD < 3 months (short NAD: S-NAD), 3 months ≤ NAD < 6 months (middle NAD: M-NAD), and NAD ≥ 6 months (long NAD: L-NAD). The prostate volume reductions at the 36th treatment fraction, relative to the planning CT, were 7.8%, 2.0%, and 1.7% for the S-NAD, M-NAD, and L-NAD groups, respectively. Prostate volume shrunk greater in the S-NAD group than in the M-NAD and L-NAD groups; this finding was consistent with those of previous studies. The prostate volume changes in Japanese patients were smaller compared to those in European and American patients.
authors: Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan; Radiological Technology, Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan.
authors: Masashi
authors: M
authors: Tomida
authors: Radiological Technology, Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan.
authors: Kuniyasu
authors: K
authors: Okudaira
authors: Department of Therapeutic Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Takeshi
authors: T
authors: Kamomae
authors: Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Hiroshi
authors: H
authors: Oguchi
authors: Radiological Technology, Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan.
authors: Yoshikazu
authors: Y
authors: Miyake
authors: Radiological Technology, Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan.
authors: Kazuo
authors: K
authors: Yoneda
authors: Department of Therapeutic Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Yoshiyuki
authors: Y
authors: Itoh
mesh_terms: D000726:Androgen Antagonists; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy; D017430:Prostate-Specific Antigen; D011471:Prostatic Neoplasms; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies
chemical_list: D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen
keywords: IGRT; IMRT; Japanese patients; neoadjuvant androgen deprivation; prostate cancer