PMID- 24884868
OWN - NLM
STAT- MEDLINE
DCOM- 20150219
LR  - 20211021
IS  - 1748-717X (Electronic)
IS  - 1748-717X (Linking)
VI  - 9
DP  - 2014 May 21
TI  - Early results of urethral dose reduction and small safety margin in 
      intensity-modulated radiation therapy (IMRT) for localized prostate cancer using 
      a real-time tumor-tracking radiotherapy (RTRT) system.
PG  - 118
LID - 10.1186/1748-717X-9-118 [doi]
AB  - BACKGROUND: We prospectively assessed the utility of intensity-modulated 
      radiation therapy (IMRT) with urethral dose reduction and a small margin between 
      the clinical target volume (CTV) and the planning target volume (PTV) for 
      patients with localized prostate cancer. METHODS: The study population was 110 
      patients in low- (14.5%), intermediate- (41.8%), and high-risk (43.6%) 
      categories. Three gold fiducial markers were inserted into the prostate. A soft 
      guide-wire was used to identify the urethra when computed tomography (CT) scan 
      for treatment planning was performed. A dose constraint of V70 < 10% was applied 
      to the urethral region. Margins between the CTV-PTV were set at 3 mm in all 
      directions. Patients were treated with 70 Gy IMRT in 30 fractions (D95 of PTV) 
      over 7.5 weeks. The patient couch was adjusted to keep the gold markers within 
      2.0 mm from their planned positions with the use of frequent on-line 
      verification. RESULTS: The median follow-up period was 31.3 (3.2 to 82.1) months. 
      The biochemical relapse-free survival (bRFS) rates at 3 years were 100%, 93.8% 
      and 89.5% for the low-, intermediate-, and high-risk patients, respectively. The 
      incidences of acute adverse events (AEs) were 45.5% and 0.9% for grades 1 and 2, 
      respectively. The late AEs were grade 1 cystitis in 10.0% of the patients, rectal 
      bleeding in 7.3%, and urinary urgency in 6.4%. Only three patients (2.7%) 
      developed grade 2 late AEs. CONCLUSIONS: On-line image guidance with precise 
      correction of the table position during radiotherapy achieved one of the lowest 
      AEs rates with a bRFS equal to the highest in the literature.
FAU - Shimizu, Shinichi
AU  - Shimizu S
AD  - Department of Radiation Medicine, Hokkaido University Graduate School of 
      Medicine, Sapporo, Japan. sshing@med.hokudai.ac.jp.
FAU - Nishioka, Kentaro
AU  - Nishioka K
FAU - Suzuki, Ryusuke
AU  - Suzuki R
FAU - Shinohara, Nobuo
AU  - Shinohara N
FAU - Maruyama, Satoru
AU  - Maruyama S
FAU - Abe, Takashige
AU  - Abe T
FAU - Kinoshita, Rumiko
AU  - Kinoshita R
FAU - Katoh, Norio
AU  - Katoh N
FAU - Onimaru, Rikiya
AU  - Onimaru R
FAU - Shirato, Hiroki
AU  - Shirato H
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20140521
PL  - England
TA  - Radiat Oncol
JT  - Radiation oncology (London, England)
JID - 101265111
SB  - IM
MH  - Aged
MH  - Follow-Up Studies
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Neoplasm Staging
MH  - Prognosis
MH  - Prospective Studies
MH  - Prostatic Neoplasms/pathology/*radiotherapy
MH  - Radiotherapy Dosage
MH  - *Radiotherapy Planning, Computer-Assisted
MH  - *Radiotherapy, Intensity-Modulated
MH  - Tumor Burden/*radiation effects
MH  - Urethra/*radiation effects
PMC - PMC4035733
EDAT- 2014/06/03 06:00
MHDA- 2015/02/20 06:00
PMCR- 2014/05/21
CRDT- 2014/06/03 06:00
PHST- 2014/01/10 00:00 [received]
PHST- 2014/05/03 00:00 [accepted]
PHST- 2014/06/03 06:00 [entrez]
PHST- 2014/06/03 06:00 [pubmed]
PHST- 2015/02/20 06:00 [medline]
PHST- 2014/05/21 00:00 [pmc-release]
AID - 1748-717X-9-118 [pii]
AID - 10.1186/1748-717X-9-118 [doi]
PST - epublish
SO  - Radiat Oncol. 2014 May 21;9:118. doi: 10.1186/1748-717X-9-118.