Clinical Investigation:Gastrointestinal Cancer
Australasian Gastrointestinal Trials Group(AGITG) Contouring Atlas and Planning Guidelines for
Intensity-Modulated Radiotherapy in Anal Cancer
Michael Ng,M.B.B.S.(Hons),F.R.A.N.Z.C.R.,*
Trevor Leong,M.B.B.S.,M.D.,F.R.A.N.Z.C.R.,y,k
Sarat Chander,M.B.B.S.,F.R.A.N.Z.C.R.,y Julie Chu,M.B.B.S.,F.R.A.N.Z.C.R.,y Andrew Kneebone,M.B.B.S.,F.R.A.N.Z.C.R.,z,**
职业生涯规划可以Susan Carroll,M.B.B.S.,F.R.A.N.Z.C.R.,x,**Kirsty Wiltshire,M.B.B.S.,F.R.A.N.Z.C.R.,y Samuel Ngan,M.B.B.S.,F.R.C.S.Ed.,F.R.A.N.Z.C.R.,y,k and Lisa Kachnic,M.D.{
*Radiation Oncology Victoria,Victoria,Australia;y Department of Radiation Oncology,Peter MacCallum Cancer Centre,
ttledVictoria,Australia;z Department of Radiation Oncology,Northern Sydney Cancer Centre,Royal North Shore Hospital,
千方百计的近义词
NSW,Australia;x Department of Radiation Oncology,Sydney Cancer Centre,Royal Prince Alfred Hospital,NSW,Australia; {Department of Radiation Oncology,Boston Medical Center,Boston University School of Medicine,Boston,MA;
k University of Melbourne,Australia;and**University of Sydney,Australia
Received Jun19,2011,and in revid form Dec13,2011.Accepted for publication Dec18,2011
Summary Chemoradiation is the stan-dard of care for patients with anal canal SCC.IMRT is increasingly ud to reduce treatment-associated toxicity. Critical to its u is accurate and consistent volume con-touring.This publication reprents the AGITG connsus recommendations of tumor,nodal and organ at risk volume delineation in anal cancer.Provided are detailed guidelines and
a high resolution atlas which Purpo:To develop a high-resolution target volume atlas with intensity-modulated radio-therapy(IMRT)planning guidelines for the conformal treatment of anal cancer.
Methods and Materials:A draft contouring atlas and planning guidelines for anal cancer IMRT were prepared at the Australasian Gastrointestinal Trials Group(AGITG)annual meeting in September2010.
An expert panel of radiation oncologists contoured an anal cancer ca to generate discussion on recommendations regarding target definition for gross dia,elective nodal volumes,and organs at risk(OARs).Clinical target volume(CTV)and planning target volume(PTV)margins,do fractionation,and other IMRT-specific issues were also addresd.
A steering committee produced thefinal connsus guidelines.
Results:Detailed contouring and planning guidelines and a high-resolution atlas are provided. Gross tumor and elective target volumes are described and pictorially depicted.All elective regions should be routinely contoured for all dia stages,with the possible exception of the inguinal and high pelvic nodes for lect,early-stage T1N0.A20-mm CTV margin for the primary,10-to20-mm CTV margin for involved nodes and a7-mm CTV margin for the elective pelvic nodal groups are recommended,while respecting anatomical boundaries.A5-to10-mm PTV margin is suggested.When using a simultaneous integrated boost technique, a do of54Gy in30fractions to gross dia and45Gy to elective nodes with chemotherapy is appropriate.Guidelines are provided for OAR delineation.
Reprint requests to:Michael Ng,M.B.B.S.(Hons), F.R.A.N.Z.C.R., Radiation Oncology Victoria,230Co
oper Street,Epping,3076,Victoria.Australia.Tel:þ613-9418-2200;Fax:þ613-9418-2288;E-mail:mng@ au
Conflict of interest:none.
Int J Radiation Oncol Biol Phys,V ol.83,No.5,pp.1455e1462,2012 0360-3016/$-e front matterÓ2012Elvier Inc.All rights rerved. doi:10.1016/j.ijrobp.2011.12.058Radiation Oncology International Journal of biology physics
will be uful to the prac-ticing radiation oncologist.Conclusion:The connsus planning guidelines and high-resolution atlas complement the ex-isting Radiation Therapy Oncology Group(RTOG)elective nodal ano-rectal atlas and provide additional anatomic,clinical,and technical instructions to guide radiation oncologists in the planning and delivery of IMRT for anal cancer.Ó2012Elvier Inc.
Keywords:Anal cancer,IMRT,Chemoradiation,Atlas,Guidelines
Introduction
With the advent of computed tomography(CT)planning and conformal radiation techniques including intensity-modulated radiotherapy(IMRT),comes the prerequisite for accurate and consistent contouring of target volumes.
Conformal radiotherapy for anal cancer allows the ability to spare surrounding organs at risk(OAR).Normal tissues such as small bowel,femoral heads,perineum,and external genitalia often receive high dos of radiation with more conventional tech-niques,which can result in significant acute and late toxicity.The u of IMRT provides an opportunity to spare OAR and to reduce toxicity in anal cancer patients.
The implementation of IMRT requires a clear understanding of target volume definition for the complex elective nodal regions in anal cancer.During the early conduct of the Radiation Therapy Oncology Group(RTOG)0529Pha II study investigating IMRT for anal cancer,it became necessary to create an atlas becau many initial target volumes submitted for quality assurance required contouring revision(1).However,this atlas provided contouring guidance for elective nodal volumes only and did not provide instruction in the contouring of gross dia and OAR.
As such,an international workshop was convened at the2010 Australasian Gastrointestinal Trials Gro
萝岗香雪up(AGITG)annual meeting to develop detailed contouring and planning guidelines for the IMRT treatment of anal cancer,supplemented by a high-resolution atlas.This article reports the AGITG recommendations. Methods and Materials
The AGITG is a national cooperative trials group that consists of radiation oncologists,surgeons,and medical oncologists who conduct clinical trials in gastrointestinal malignancies.In2010, the Radiation Oncology Committee of AGITG organized a con-touring workshop with member radiation oncologists to discuss radiotherapy target and OAR volume delineation for anal cancer, with the aim of developing connsus guidelines.Dr.Lisa Kachnic (L.K.),principal investigator of the RTOG0529study of IMRT in anal cancer,was invited to participate in the workshop.
To facilitate discussion and productivity at the workshop, a draft t of IMRT contouring and planning guidelines was nt to all19workshop participants before the meeting.The were bad on anal canal IMRT guidelines previously developed in 2009by the Gastrointestinal Unit at the Peter MacCallum Cancer Centre(PMCC).The aim of the PMCC guidelines,building off of previous publications describing clinical target volume(CTV) delineation for ano-rectal cancer(2,3),was to standardize CTVs among radiation oncologists.简历封面模板
The draft guidelines described ven elective regions to be considered when treating anal cancer,including the mesorectum, presacral space,internal iliac lymph nodes,external iliac lymph nodes,obturator lymph nodes,ischiorectal fossa,and inguinal lymph nodes.Each elective region was described individually, including borders for CTV delineation.The guidelines also con-tained recommendations for contouring target volumes for gross dia and instructions for standardized contouring of OAR. Planning target volume(PTV)margins,do fractionation,and other IMRT-specific issues were also addresd.
The AGITG workshop was coordinated by two chairs,A.K.and M.N.,and three radiation oncologists(T.L.,S.Ca.and L.K.)who were invited to form a discussion panel.Before the meeting,each panelist was nt an anonymized CT datat of a female patient with a T2N0anal cancer.The gross tumor volume(GTV)was already defined,and panelists were asked to delineate the above target volumes and OAR.The volumes were then displayed,rving as discussion points for the development of connsus guidelines and an atlas(Fig.3e5:Atlas Panels1,2,3respectively).Where available, references are provided with thefinal recommendations. Results
Elective nodal volumes
Mesorectum
The mesorectum is not well visualized on CT,and if fat-saturated T2magnetic resonance imaging cannot be obtained,neighboring structures can be ud to delineate this volume.
Cranial:The level of the recto-sigmoid junction;best identified where the rectum runs anteriorly to join the sigmoid colon(Atlas 4b).
Caudal:The ano-rectal junction,defined by where the levator muscles fu with the external sphincter muscles,where meso-rectal fat/space is no longer en tapering inferiorly(Atlas10a). Often this level can be identified by a plane drawn from the caudal edge of the pubic symphysis to the coccyx trancting the rectum (Fig.1).
Posterior:The presacral space(Atlas5b).
天蝎座的幸运数字
Anterior:For males,the boundary is formed by the penile bulb and prostate in the lower pelvis,and by the posterior edge of the minal vesicles(SV)and bladder in the mid pelvis(Atlas6b).In females,the boundary is formed by the bladder,vagina,cervix, and uterus.An internal margin of10mm should be added to this anterior mesorectal border on axial slices containing bladder,SV, or uterus to account for the effect of bladder volume variation (Atlas5c e8c)(4).
Lateral:In the lower pelvis,the border is the medial edge of the levator ani(Atlas9b).In the upper pelvis,it is the internal iliac lymph node group(Atlas4b).
Presacral space
The presacral space lies posterior to the mesorectum and contains lymph nodes that may harbor micro-metastatic dia.
Cranial:The sacral promontory,defined at the L5e S1 interspace(Atlas1b).
Caudal:The inferior edge of the coccyx(Atlas8b).
Lateral:The sacro-iliac joints(Atlas3b).
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Anterior:Ten mm anterior to the anterior sacral border encompassing any lymph nodes or presacral vesls (Atlas 2b)(5).Posterior:The position at the anterior border of the sacral bone.The sacral hollows should be included in this volume (Atlas 3a).
Internal iliac lymph nodes
This group of nodes lies lateral to the mesorectum and pre-sacral space and are associated with the internal iliac vesls.Cranial:Bifurcation of the common iliac artery into the external and internal iliac arteries (usually corresponds to the L5e S1interspace level)(Atlas 1a).
Caudal:This volume typically ends caudally where the fibers of the levator ani inrt into the obturator fascia and obturator internus,and can be demarcated either at the level of the obturator canal,or at the level where there is no space between the obturator internus muscle and the midline organs (bladder,SV)(Atlas 8b).Lateral:The medial edge of the obturator internus muscle (or bone where the obturator internus is not prent)in the lower pelvis (Atlas 7b);iliopsoas muscle in the upper pelvis.(Atlas 2b)Medial:The mesorectum and the presacral space in the lower pelvis (Atlas 8b).In the upper pelvis,a 7-mm medial margin is recommended from the internal iliac vesls (5).
Anterior:The obturator internus muscle or bone in the lower pelvis.In the upper pelvis,a 7-mm margin around the internal iliac vesls (Atlas 1b).Ischiorectal fossa (IRF)
Cranial:The apex of the IRF is formed by the levator ani,gluteus maximus,and obturator internus (Atlas 9b).
Caudal:There exists no anatomical structure that delineates the most inferior level of the IRF,and we
suggest that this corresponds with the level of the anal verge (Atlas 12a).
Lateral:The lateral walls of the IRF are formed by the ischial tuberosity,obturator internus,and gluteus maximus muscles (Atlas 10a).
Anterior:The level where the obturator internus muscle,levator ani,and anal sphincter muscles fu (Atlas 10b).Inferiorly,at least 10-to 20-mm anterior to the sphincter muscles.
Posterior:A transver plane joining the anterior edge of the medial walls of the gluteus maximus muscle (Atlas 10b).Obturator nodes
The nodes lie along the obturator artery,a branch of the in-ternal iliac artery that usually starts at the level of the acetabulum.This branch travels inferiorly and anteriorly,exiting the pelvis via the obturator canal.The target volume for the obturator nodes is small,being 3-to 5-mm in the cranio-caudal axis (Atlas 6b).Cranial:Three to 5mm cranial to the obturator canal where the obturator artery is sometimes visible.
Caudal:The obturator canal (Atlas 7a),where the obturator artery has exited the pelvis.
Anterior:The anterior extent of the obturator internus muscle.Posterior:The internal iliac lymph node
group.Lateral:The obturator internus muscle.Medial:The bladder.External iliac lymph nodes
The draining lymphatics are associated with the external iliac vesls.
Cranial:Bifurcation of the common iliac artery into the external and internal iliac arteries (Atlas 1a).
Caudal:The level where the external iliac vesls are still located within the bony pelvis (Atlas 5a)before continuing as the femoral artery.This transition usually occurs between the acetabulum’s roof and the superior pubic rami (Fig.2).
Lateral:The iliopsoas muscle (Atlas 4a).
Medially:Usually,the bladder forms the medial wall;otherwi a 7-mm margin around the vesls (Atlas 5b).
Anterior:A 7-mm margin anterior to the external iliac vesls (Atlas 3b).
Posterior:The internal iliac lymph node group (Atlas 4b).Inguinal lymph nodes
There is a lack of evidence to define the borders of the inguinal lymph node group.Both superficial a
爱你中国nd deep inguinal lymph nodes of the femoral triangle,and any visible lymph nodes or lympho-coeles outside the following boundaries,should be
included.
Fig. 1.Caudal level of mesorectum clinical target volume
(CTV).
元宵节作文300字Fig.2.Transition of external iliac clinical target volume (CTV)to inguinal CTV .
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Fig.3.Atlas panel1.
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Fig.4.Atlas panel2.
