Simulated Prostate Biopsy: Prostate Cancer Distribution and Clinical Correlation

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Simulated Prostate Biopsy Prostate Cancer
Distribution and Clinical Correlation

• John J. Bauer, Jianchao Zeng, Wei Zhang, David G.
  McLeod, Isabell A. Sesterhenn, Roger R. Connelly,
  Judd W. Moul and Seong K. Mun
• Walter Reed Army Medical Center
• Georgetown University
• Armed Forces Institute of Pathology
• Center for Prostate Disease Research (CPDR),
  USUHS

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Systematic Prostate Biopsy

• Currently adopted protocol is the sextant
• positive in only 1/3 of cases with elevated PSA
• 20-40 positive repeat biopsies
• Other approaches have been investigated to
  increase the detection rate and decrease the need
  for re-biopsy
• Objective Optimization
• of prostate needle biopsy

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Outline of Presentation

• Comparison of existing protocols with biopsy
  simulation
• Clinical correlation
• 3D distribution map of prostate cancer

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3-D Biopsy Simulator

• Prostate modeling (whole-mounted, step-sectioned
  at 2.5 mm slices)
• single pathologist
• single urologist
• detection rates for various protocols were
  determined
• 4-lateral biopsies, sextant, lateral sextant,
  10-, 12-, 14-, 5-region, TZ and SVs

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3-D Surface Modeling
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3-D Biopsy Simulator Results(with 280 models)

• 4-pattern 93.5
• Sextant 72.6
• lateral Sextant 95.5
• 10-pattern 99.0
• 12-pattern 99.0
• 14-pattern 99.0
• 5-region 90.5
• TZ 21.3
• SV 2.9

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Positive Needle Biopsy
Frequencies by Prostate Region
LEFT RIGHT Base
24.4 20.4Mid
44.8 35.3 Apex
33.8 30.9 Lateral Base 37.7
30.8 Lateral Mid 58.7
47.8 Lateral Apex 50.7 47.8
MIDDLE Base 18.4 Apex 22.9
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Summary

• 10-pattern biopsy has the most reliable detection
  rate for the number of biopsies (99.0)
• laterally placed biopsies have the highest
  detection frequencies

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Clinical Correlation

• 35 consecutive patients with biopsy proven
  prostate cancer
• single urologist
• 10-pattern biopsy technique
• sextant biopsies
• 4 laterally placed biopsies
• Comparison sextant, lateral Bx, 10-pattern

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Results

• Sextant data only------------gt 19/35 54.3
• lateral biopsies only---------gt 30/35 85.7
• 10-pattern biopsies----------gt 35/35 100.0
• When sextant negative---gt lateral biopsies
• detected additional 19 cancers
• When lateral biopsies were negative---gt
  sextant pattern detected an additional 5 cancers

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Positive Needle Biopsy Frequencies by Prostate
Region (35 consecutive biopsies positive for
CAP)
Base 18.6
Mid 17.2
Apex 21.5
Lateral Mid 32.9
Lateral Apex 32.9
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Summary

• The clinical data suggests that the 10- pattern
  biopsy developed using the simulated prostate
  models is superior to the currently used
  traditional sextant biopsy technique

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Tumor Distribution
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Distribution map in transverse
Base Mid Apex
Base
Apex
Mid
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An Example of Optimal Biopsy

• The following combination of 8 biopsies achieves
  100 positive results of all 280 prostate models

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Apex
Mid
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Conclusions

• Prostate needle biopsy protocols can be optimized
• The 10-pattern protocol proves to be optimal both
  by simulation and clinical data
• Prostate tumor distribution may help develop
  better protocols
• One optimized biopsy protocol has been developed
  that will be tested clinically

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Future Research

• Enhance the current distribution model by
  increasing total prostate models
• More comprehensive statistical analysis of the
  distribution map by race, age, grades...
• Development of optimal biopsy protocols based on
  tumor distribution map
• Apply the 3-D prostate tumor distribution map to
  the real-time in vivo image-guided biopsy
  procedures

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Acknowledgements

• This research has been supported in part by The
  Whitaker Foundation Biomedical Engineering
  Program, US Army Medical Research and Materiel
  Command, and Center for Prostate Disease Research
• For more info
• zeng_at_isis.imac.georgetown.edu
• http//www.simulation.georgetown.edu