ProstateFossaContouringGuide

JillGunther,MDModifiedbytheeContourTeam

Youwanttocontour:Post-opProstateWhatnow?

•  Findyourreferences–  RTOGProstateFossaContouringAtlas

•  hDps://www.rtog.org/CoreLab/ContouringAtlases/ProstatePostOp.aspx

–  ConsensusguidelinepublicaJons•  Michalski,IJROBP2010•  Wiltshire,IJROBP2007

–  RTOGtrialswithcontouringdescripJonsforIMRTdescribedintheprotocol

•  RTOG0534(ongoing)–  eContour.orgaimstobeyourone-stopshopforhighyieldanatomyandcontouringguidelines,includinghyperlinkstoeachoftheabove!

Youwanttocontour:Post-opProstateCheckeContour.orgforguidance!

1.  FromHOMEPAGEclickCASES

2.  GUàProstateàpost-prostatectomy(notintact)

3.  Reviewanatomy

4.  DrawOARs(rectumandpenilebulb)

5.  DrawtheCTV

6.  Addmargin/expansiontocreatefinalPTVfortreatmentplanning.

Quickreviewofbasicanatomyofprostate/pelvis

BladderSacrum

Seminalvesicles(proximaljustmeanssegmentclosetoprostate)

Rectum

Prostate

Pubicsymphysis

SagiDalviewBaseofprostate

Apexofprostate

SeminalVesicles

CoronalviewBladder

Prostate

Rectum

Bladder

Prostate

Femoral heads

Axial view

AnatomicalBordersofPost-OpCTVforProstateCancer

Michalski,IJROBP,2010

StarJngInferiorly•  Findthelowestsliceaccordingtoyourguidelines

•  Locatethevesicourethralanastomosis(VUA)whichiswherethebladderwasreaDachedtotheurethraaberremovaloftheprostate

•  IfdifficulttolocateVUA,usesliceabovepenilebulb

VUA

StartCTV:4slicesbelowVUA

Eachslice=2.5mm,so4slicesputsus10mmbelowVUA

ScrollingthroughCTimages,movingsuperiorly

Levatorani

Posterioredgeofpubicbone

Boundaries(inferiortopubicsymphysis)

Anteriorrectalwall

Obturatorinternusmuscle

Posterioredgeofpubicbone

Anteriorrectalwall

Obturatorinternus

Boundaries(inferiortopubicsymphysis)

Whataboutthebladder?

Includeit!ThisisthepreviouslocaJonoftheprostate

Mayneedtobeconcavearoundlateralaspects

WhendoIstop?

Theseboundariesapplyonlytobelow(inferior)thesuperioredgeofpubicsymphysis

Soabovesymphysisweneednewboundaries

NeedtotransiJondowntoincludingonly1-2cmposteriorbladderwall

Startpullingbackposteriorly

ConJnuepullingbackposteriorlyoverafewslicesunJl…

Green=BladderminusCTV

ConJnuethisstepwisereducJoninvolumeoverseveralCTslices

Include1-2cmposteriorbladderwall

Obturatorinternus*

Posterior1-2cmbladderwall

Mesorectalfascia/rectalwall

Vasdeferensmayretractpost-op;includeSVremnantsifpathologicalyinvolved

Includeallsurgicalclipsthatarefelttobeintheprostatebed

(canhaveclipsfromnodaldissecJon)

WhendoIstop?

WhendoIstop?

SagiDalview 3-4cmabovepubicsymphysis

8-12mmbelowvesico-urethralanastomosis(justabovepenilebulb)

Coronalview

AlwayscheckcoronalandsagiDalviewstomakesureyourvolumemakessense

Guidelinesareguidelines

•  ConsiderwhatiscorrectforeachpaJent•  WherewashisiniJaldisease?•  WasthereextraprostaJcextension?

– Where?•  Weretheseminalvesiclesinvolved?•  WasthereaposiJvemargin?Ifso,where?

•  Thatsaid,usingconsensusguidelinesortreatedperprotocolisusuallyasafeapproach!

DISCLAIMER:EachcaseisuniqueandrequiresdecisionmakingbasedonclinicaljudgmentofthetreaHngphysician.

SomeaddmoremargintoguidelineswithconsideraJonofspecificpaJentriskfactors

Extendintopubicsymphysis(ex.PaJentwithanteriorlesionwithanteriorEPE

SVfossacontouredseparately

Extendedintoanteriorrectalwall(ex.PaJenthasclipssikngalongrectalwall)

References•  RTOGcontouringatlas

–  hDp://www.rtog.org/CoreLab/ContouringAtlases/ProstatePostOp.aspx

•  Wiltshire,K.L.,etal.(2007)."Anatomicboundariesoftheclinicaltargetvolume(prostatebed)aberradicalprostatectomy."IntJRadiatOncolBiolPhys69(4):1090-1099.

•  Michalski,J.M.,etal.(2010)."DevelopmentofRTOGconsensusguidelinesforthedefiniJonoftheclinicaltargetvolumeforpostoperaJveconformalradiaJontherapyforprostatecancer."IntJRadiatOncolBiolPhys76(2):361-368.