Prostate Fossa Contouring Guide. Jill Gunther, MD Modified by the econtour Team

Transcription

1 Prostate Fossa Contouring Guide Jill Gunther, MD Modified by the econtour Team

2 You want to contour: Post-op Prostate What now? Find your references RTOG Prostate Fossa Contouring Atlas hdps:// ProstatePostOp.aspx Consensus guideline publicajons Michalski, IJROBP 2010 Wiltshire, IJROBP 2007 RTOG trials with contouring descripjons for IMRT described in the protocol RTOG 0534 (ongoing) econtour.org aims to be your one-stop shop for high yield anatomy and contouring guidelines, including hyperlinks to each of the above!

3 You want to contour: Post-op Prostate Check econtour.org for guidance! 1. From HOME PAGE click CASES 2. GU à Prostate à postprostatectomy (not intact) 3. Review anatomy 4. Draw OARs (rectum and penile bulb) 5. Draw the CTV 6. Add margin/expansion to create final PTV for treatment planning.

4 Quick review of basic anatomy of prostate/pelvis Bladder Sacrum Seminal vesicles (proximal just means segment close to prostate) Pubic symphysis Rectum Prostate

5 SagiDal view Base of prostate Seminal Vesicles Apex of prostate

6 Coronal view Bladder Prostate

7 Axial view Bladder Femoral heads Prostate Rectum

8 Anatomical Borders of Post-Op CTV for Prostate Cancer Michalski, IJROBP, 2010

9 StarJng Inferiorly Find the lowest slice according to your guidelines Locate the vesicourethral anastomosis (VUA) which is where the bladder was readached to the urethra aber removal of the prostate If difficult to locate VUA, use slice above penile bulb

10 VUA

11 Start CTV: 4 slices below VUA Each slice = 2.5mm, so 4 slices puts us 10mm below VUA

12 Scrolling through CT images, moving superiorly

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15 Boundaries (inferior to pubic symphysis) Posterior edge of pubic bone Obturator internus muscle Levator ani Anterior rectal wall

16 Boundaries (inferior to pubic symphysis) Posterior edge of pubic bone Obturator internus Anterior rectal wall

17 What about the bladder? Include it! This is the previous locajon of the prostate

18 May need to be concave around lateral aspects

19 When do I stop? These boundaries apply only to below (inferior) the superior edge of pubic symphysis

20 So above symphysis we need new boundaries Need to transijon down to including only 1-2cm posterior bladder wall

21 Start pulling back posteriorly

22 ConJnue pulling back posteriorly over a few slices unjl Green = Bladder minus CTV ConJnue this stepwise reducjon in volume over several CT slices

23 Include 1-2cm posterior bladder wall Obturator internus* Posterior 1-2cm bladder wall Mesorectal fascia/ rectal wall

24 Vas deferens may retract post-op; include SV remnants if pathologicaly involved

25 Include all surgical clips that are felt to be in the prostate bed (can have clips from nodal dissecjon)

26 When do I stop?

27 When do I stop?

28 SagiDal view 3-4cm above pubic symphysis 8-12 mm below vesicourethral anastomosis (just above penile bulb)

29 Coronal view Always check coronal and sagidal views to make sure your volume makes sense

30 Guidelines are guidelines Consider what is correct for each pajent Where was his inijal disease? Was there extraprostajc extension? Where? Were the seminal vesicles involved? Was there a posijve margin? If so, where? That said, using consensus guidelines or treated per protocol is usually a safe approach! DISCLAIMER: Each case is unique and requires decision making based on clinical judgment of the treahng physician.

31 Some add more margin to guidelines with considerajon of specific pajent risk factors Extend into pubic symphysis (ex. PaJent with anterior lesion with anterior EPE SV fossa contoured separately Extended into anterior rectal wall (ex. PaJent has clips sikng along rectal wall)

32 References RTOG contouring atlas hdp:// ProstatePostOp.aspx Wiltshire, K. L., et al. (2007). "Anatomic boundaries of the clinical target volume (prostate bed) aber radical prostatectomy." Int J Radiat Oncol Biol Phys 69(4): Michalski, J. M., et al. (2010). "Development of RTOG consensus guidelines for the definijon of the clinical target volume for postoperajve conformal radiajon therapy for prostate cancer." Int J Radiat Oncol Biol Phys 76(2):