PMID- 22270169
OWN - NLM
STAT- MEDLINE
DCOM- 20120816
LR  - 20191210
IS  - 1879-355X (Electronic)
IS  - 0360-3016 (Linking)
VI  - 83
IP  - 4
DP  - 2012 Jul 15
TI  - Postoperative radiotherapy in prostate cancer: the case of the missing target.
PG  - 1160-8
LID - 10.1016/j.ijrobp.2011.09.039 [doi]
AB  - PURPOSE: Postoperative radiotherapy (XRT) increases survival in high-risk 
      prostate cancer patients. Approximately 50% of patients on long-term follow-up 
      relapse despite adjuvant XRT and the predominant site of failure remains local. 
      Four consensus guidelines define postoperative clinical target volume (CTV) in 
      prostate cancer. We explore the possibility that inadequate CTV coverage is an 
      important cause of local failure. This study evaluates the utility of 
      preoperative magnetic resonance imaging (MRI) in defining prostate bed CTV. 
      METHODS AND MATERIALS: Twenty prostate cancer patients treated with postoperative 
      XRT who also had preoperative staging MRI were included. The four guidelines were 
      applied and the CTVs were expanded to create planning target volumes (PTVs). 
      Preoperative MRIs were fused with postoperative planning CT scans. MRI-based 
      prostate and gross visible tumors were contoured. Three-dimensional (3D) 
      conformal four- and six-field XRT plans were developed and dose-volume histograms 
      analyzed. Subtraction analysis was conducted to assess the adequacy of 
      prostate/gross tumor coverage. RESULTS: Gross tumor was visible in 18 cases. In 
      all 20 cases, the consensus CTVs did not fully cover the MRI-defined prostate. On 
      average, 35% of the prostate volume and 32% of the gross tumor volume were missed 
      using six-field 3D treatment plans. The entire MRI-defined gross tumor volume was 
      completely covered in only two cases (six-field plans). The expanded PTVs did not 
      cover the entire prostate bed in 50% of cases. Prostate base and mid-zones were 
      the predominant site of inadequate coverage. CONCLUSIONS: Current postoperative 
      CTV guidelines do not adequately cover the prostate bed and/or gross tumor based 
      on preoperative MRI imaging. Additionally, expanded PTVs do not fully cover the 
      prostate bed in 50% of cases. Inadequate CTV definition is likely a major 
      contributing factor for the high risk of relapse despite adjuvant XRT. 
      Preoperative imaging may lead to more accurate CTV definition, which should 
      result in further improvements in survival for patients with high-risk prostate 
      cancer.
CI  - Copyright (c) 2012 Elsevier Inc. All rights reserved.
FAU - Croke, Jennifer
AU  - Croke J
AD  - Division of Radiation Oncology, The Ottawa Hospital Cancer Centre, The University 
      of Ottawa, Ottawa, Ontario, Canada.
FAU - Malone, Shawn
AU  - Malone S
FAU - Roustan Delatour, Nicolas
AU  - Roustan Delatour N
FAU - Belanger, Eric
AU  - Belanger E
FAU - Avruch, Leonard
AU  - Avruch L
FAU - Morash, Christopher
AU  - Morash C
FAU - Kayser, Cathleen
AU  - Kayser C
FAU - Underhill, Kathryn
AU  - Underhill K
FAU - Spaans, Johanna
AU  - Spaans J
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120121
PL  - United States
TA  - Int J Radiat Oncol Biol Phys
JT  - International journal of radiation oncology, biology, physics
JID - 7603616
SB  - IM
MH  - Aged
MH  - Humans
MH  - Magnetic Resonance Imaging/*methods
MH  - Male
MH  - Middle Aged
MH  - Neoplasm Staging/methods
MH  - *Practice Guidelines as Topic
MH  - Preoperative Care/methods
MH  - Prostatic Neoplasms/diagnostic imaging/*pathology/*radiotherapy/surgery
MH  - Radiotherapy Planning, Computer-Assisted/*methods
MH  - Radiotherapy Setup Errors
MH  - Radiotherapy, Image-Guided/methods
MH  - Tomography, X-Ray Computed/methods
MH  - *Tumor Burden
EDAT- 2012/01/25 06:00
MHDA- 2012/08/17 06:00
CRDT- 2012/01/25 06:00
PHST- 2010/09/17 00:00 [received]
PHST- 2011/07/22 00:00 [revised]
PHST- 2011/09/29 00:00 [accepted]
PHST- 2012/01/25 06:00 [entrez]
PHST- 2012/01/25 06:00 [pubmed]
PHST- 2012/08/17 06:00 [medline]
AID - S0360-3016(11)03312-8 [pii]
AID - 10.1016/j.ijrobp.2011.09.039 [doi]
PST - ppublish
SO  - Int J Radiat Oncol Biol Phys. 2012 Jul 15;83(4):1160-8. doi: 
      10.1016/j.ijrobp.2011.09.039. Epub 2012 Jan 21.