open access
Does intensity-modulated radiation therapy (IMRT) alter prostate size? Magnetic resonance imaging evaluation of patients undergoing IMRT alone
open access
Abstract
Aim
To assess the changes in prostate size in patients with prostate cancer undergoing intensity-modulated radiation therapy (IMRT).
Background
The effect of size change produced by IMRT is not well known.
Materials and methods
We enrolled 72 patients who received IMRT alone without androgen-deprivation therapy and underwent magnetic resonance imaging (MRI) examination before and after IMRT. The diameter of the entire prostate in the anterior–posterior (P-AP) and left–right (P-LR) directions was measured. The transitional zone diameter in the anterior–posterior (T-AP) and left–right (T-LR) directions was also measured.
Results
The average relative P-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.94, 0.90, 0.89, 0.89, and 0.90, respectively; the average relative P-LR values were 0.93, 0.92, 0.91, 0.91, and 0.90, respectively. The average P-AP and P-LR decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. The average relative T-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.93, 0.88, 0.91, 0.87, and 0.89, respectively; the average relative T-LR values were 0.96, 0.90, 0.91, 0.87, and 0.88, respectively. The average T-AP and T-LR also decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. At 12 months after IMRT, the average relative T-AP was significantly lower in patients with recurrence than in those without recurrence.
Conclusions
The average prostate diameter decreased by approximately 10% during the 12 months after IMRT; thereafter remained unchanged.
Abstract
Aim
To assess the changes in prostate size in patients with prostate cancer undergoing intensity-modulated radiation therapy (IMRT).
Background
The effect of size change produced by IMRT is not well known.
Materials and methods
We enrolled 72 patients who received IMRT alone without androgen-deprivation therapy and underwent magnetic resonance imaging (MRI) examination before and after IMRT. The diameter of the entire prostate in the anterior–posterior (P-AP) and left–right (P-LR) directions was measured. The transitional zone diameter in the anterior–posterior (T-AP) and left–right (T-LR) directions was also measured.
Results
The average relative P-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.94, 0.90, 0.89, 0.89, and 0.90, respectively; the average relative P-LR values were 0.93, 0.92, 0.91, 0.91, and 0.90, respectively. The average P-AP and P-LR decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. The average relative T-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.93, 0.88, 0.91, 0.87, and 0.89, respectively; the average relative T-LR values were 0.96, 0.90, 0.91, 0.87, and 0.88, respectively. The average T-AP and T-LR also decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. At 12 months after IMRT, the average relative T-AP was significantly lower in patients with recurrence than in those without recurrence.
Conclusions
The average prostate diameter decreased by approximately 10% during the 12 months after IMRT; thereafter remained unchanged.
Keywords
Prostate cancer; Intensity-modulated radiation therapy; External beam radiation therapy; Magnetic resonance imaging
About this articleTitle
Does intensity-modulated radiation therapy (IMRT) alter prostate size? Magnetic resonance imaging evaluation of patients undergoing IMRT alone
Journal
Reports of Practical Oncology and Radiotherapy
Issue
Pages
477-481
Published online
2017-11-01
DOI
10.1016/j.rpor.2017.08.009
Bibliographic record
Rep Pract Oncol Radiother 2017;22(6):477-481.
Keywords
Prostate cancer
Intensity-modulated radiation therapy
External beam radiation therapy
Magnetic resonance imaging
Authors
Hidekazu Tanaka
Takahiro Yamaguchi
Kae Hachiya
Masahide Hayashi
Shinichi Ogawa
Hironori Nishibori
Shingo Kamei
Satoshi Ishihara
Masayuki Matsuo