Special Report

Rafael Martinez-Monge, MDPatrick S. Fernandes, MDNilendu Gupta, PhDReinhard Gahbauer, MD

Cross-sectional Nodal Atlas:A Tool for the Definition ofClinical Target Volumes inThree-dimensional RadiationTherapy Planning1

Virtual three-dimensional clinical target volume definition requires the identificationof areas suspected of containing microscopic disease (frequently related to nodalstations) on a set of computed tomographic (CT) images, rather than the traditionalapproach based on anatomic landmarks. This atlas displays the clinically relevantnodal stations and their correlation with normal lymphatic pathways on a set of CTimages.

When radiation is used with curative intent, the radiation volume usually encompasses thedetectable tumor and the anatomic areas thought to be at risk for metastatic spread. TheInternational Commission on Radiation Units and Measurements Report No. 50 (1) definesgross tumor volume (GTV) as the gross palpable or visible or demonstrable extent andlocation of the malignant growth. The same report defines clinical target volume (CTV) as avolume that contains a demonstrable GTV and/or is considered to contain (only)microscopic, subclinical extensions at a certain probability level. In clinical practice, thedetermination of the extent of the CTV is based on the knowledge of the patterns of spreadfor each specific disease presentation. Additional reliable information can be obtained frompatterns-of-failure analysis and necropsy series.

For most tumors, the CTV will encompass one or more nodal stations, usually near theprimary lesion. Traditionally, the location and boundaries of these nodal stations havebeen established in reference to anatomic landmarks during the standard simulation setup.Therefore, the radiation oncologist has been specifically trained to determine the bound-aries of the different nodal stations on standard two-dimensional radiographs, especially inthe anteroposterior and posteroanterior views. With the advent of three-dimensional (3D)virtual clinical target definition, the radiation oncologist faces the challenge of definingthe CTV on cross-sectional CT or magnetic resonance images. Unfamiliarity with this newtechnique can make correlations with the known spatial references difficult to establish.

The present nodal atlas is intended to assist radiation oncologists who will use new 3Dvirtual clinical target definition and treatment planning programs.

CLASSIFICATION AND NOMENCLATURE

The anatomic patterns of lymphatic drainage for different organs to their first echelon (orefferent) nodal stations were taken from Rouviere’s Anatomy of the Human Lymphatic System(2) and confirmed with other lymphatic anatomy textbooks (3,4). The main and accessorylymphatic routes for different organs that are relevant in radiation oncology are summa-rized in Tables 1–8, with an explanation of the abbreviations appearing in the Key Box.When different subsites within an organ had unique drainage patterns, these wereindividualized in the Tables as well. The classification of and nomenclature for the differentnodal areas usually followed the guidelines of Rouviere’s system (2). In the classification ofthe mediastinal nodes, the widely used American Joint Committee on Cancer classification

Index terms:Computed tomography (CT),

three-dimensional, 99.12917,99.92

Lymphatic system, 99.12917, 99.92Special reportsTreatment planning, 99.92

Radiology 1999; 211:815–828

Abbreviations:CTV 5 clinical target volumeGTV 5 gross tumor volume3D 5 three-dimensional

1 From the Division of Radiation Oncol-ogy, the Arthur G. James Cancer Hospital,Ohio State University, 300 W Tenth Ave,Columbus, OH 43210. Received July 15,1998; revision requested August 27;revision received October 16; ac-cepted November 23. Address re-print requests to R.M.

r RSNA, 1999

Author contributions:Guarantor of integrity of entire study,R.M., R.G.; study design, R.M.; defini-tion of intellectual content, R.M.; lit-erature research, R.M., P.S.F.; dataacquisition and analysis, R.M., N.G.;manuscript preparation, R.M.; manu-script review, R.G.

815

was chosen instead (5). The nodal areasrepresented are listed in the Key Box.When clinically relevant, some nodal sta-tions were further divided into sub-groups, which are noted as lowercaseletters after the abbreviation codes pro-vided in the Tables and the Figures. Thenonparenthesized lowercase letters indi-cate differentiated subgroups, usually inthe direction of the zz8 axis. Parenthe-sized letters indicate subgroup subdivi-sion, usually in the direction of the xx8axis (shown only for inguinal and exter-nal iliac nodes).

LOCALIZATION OF NODALSTATIONS

The different nodal stations were out-lined and labeled on five different sets ofconsecutive and equidistant CT images(head and neck, thorax, abdomen, malepelvis, and female pelvis) (Figs 1–6). Weelected to use CT images because they arethe customary image support in most 3Dvirtual clinical target definition pro-grams. The nodal stations on the cross-sectional images were localized by ex-

Key Box for Abbreviations in Tables and Figures

Abbreviation Nodal Group Abbreviation Nodal Group

APWN Aortopulmonary window nodes PFL Pyriform fossa lymphaticsATL Anterior tongue lymphatics PG&N Parotid gland and nodesAxN Axillary nodes PHN Hilar nodesBTL Base tongue lymphatics PL Parametrial lymphatic plexusCIN Common iliac nodes PLN Prelaryngeal nodesCN Celiac axis nodes PPL Periprostatic lymphatic plexusCPN Cervical pretracheal nodes PRL Perirectal lymphatic plexusDN Diaphragmatic nodes PSL Paranasal sinuses lymphaticsEINGL

External iliac nodesGlottic lymphatics

PsRN Superior posterior pharyngeal wall lymphatics and retro-pharyngeal nodes

HMN High mediastinal nodes PiL Inferior posterior pharyngeal wall lymphaticsHN Hepatic nodes PTrN Mediastinal pretracheal nodesHPL Hard palate lymphatic plexus PVgL Paravaginal lymphatic plexusIGL Infraglottic lymphatics PVL Perivesical lymphatic plexusIIN Internal iliac nodes PVsN Prevascular nodesIJN Internal jugular nodes RAN Retroaortic nodesIMN Internal mammary nodes RCP Right cervical paratracheal nodesIN Superficial inguinal nodes, deep inguinal RRH Right hilum renal nodes

nodes RLP Right lower paratracheal nodesIPN Internal pudendal nodes RPN Right paraaortic nodesIRN Inferior rectal nodes RUP Right upper paratracheal nodesJVN Juxtavertebral nodes SAN Spinal accessory nodesLCP Left cervical paratracheal nodes ScIN Supraclavicular nodesLGN Left gastric nodes SCN Subcarinal nodesLPN Left paraaortic nodes SGL Supraglottic lymphatic plexusLRH Left renal hilum nodes SMaN Submandibular nodesLUP Left upper paratracheal nodes SMeN Submental nodesMN Mastoid nodes SMN Superior mesenteric nodesNL Nasopharyngeal lymphatic plexus SN Sacral nodesPAN Preaortic nodes SPL Soft palate lymphaticsPAuN Preauricular nodes SplN Splenic nodesPCL Postcricoid lymphatic plexus SRN Superior rectal nodesPecN Pectoral nodes SVL Seminal vesicles lymphatic plexusPEN Paraesophageal nodes TL Tonsil lymphatic plexus

TABLE 1Head and Neck Lymphatic System (I)

Anatomic Site First Echelon Nodal Group Subgroup Category Abbreviation

Lacrimal gland Preauricular nodes Main PAuNParotid nodes Main PG&NSubmandibular nodes Main SMaN

Eyelids, conjunctiva Preauricular nodes Main PAuNParotid nodes Main PG&NSubmandibular nodes Main SMaN

Pinna Preauricular nodes Main PAuNParotid nodes Main PG&NMastoid nodes Main MNInternal jugular nodes Upper Main IJNu

External auditory canal Parotid nodes Main PG&NInternal jugular nodes Upper Main IJNu

Middle ear Preauricular nodes Main PAuNRetropharyngeal nodes Main PsRNInternal jugular nodes Upper Main IJNu

External nose Submandibular nodes Main SMaNNasal cavity Retropharyngeal nodes Main PsRN

Internal jugular nodes Upper Main IJNuParanasal sinuses Retropharyngeal nodes Main PsRN

Internal jugular nodes Upper Main IJNuLip, upper Submandibular nodes Main SMaN

Submental nodes Accessory SMeNPreauricular nodes Accessory PAuN

Lip, lower Submandibular nodes Main SMaNSubmental nodes Main SMeN

Cheek, cutaneous Submandibular nodes Main SMaNSubmental nodes Main SMeNParotid nodes Main PG&N

Buccal mucosa Submandibular nodes Main SMaNTongue, apex Submental nodes Main SMeN

Internal jugular nodes Upper, middle Main IJNu, mTongue, lateral and posterior Submandibular nodes Main SMaN

Internal jugular nodes Upper Main IJNu

816 • Radiology • June 1999 Martinez-Monge et al

Figure 1. CT images depict head and neck nodal stations at levels hn01 through hn09 on the topogram in Figure 7.

Volume 211 • Number 3 Cross-sectional Nodal Atlas for Definition of Clinical Target Volumes • 817

trapolating information from cross-sectional anatomy atlases (6), lymphaticatlases (3), and vascular atlases (4). Toallow easy correlation, the five sets of CTimages were connected with a recogniz-able bone structure on a topogram (Fig 7).

REPRESENTATION OF THEANATOMY OF THE LYMPHATICSYSTEM IN THE NODAL ATLAS

The initial lymphatic system is composedof capillary lymphatics, which originatein the intima of the tissue and are im-mersed in the ground substance of thetissue space. These capillaries anastomosein networks to form the peripheral lym-

phatic plexuses. These plexuses are onlyrepresented in the atlas for certain organsthat are frequently irradiated while intact(prostate, rectum, some head and necksubsites, etc) to facilitate the recognitionof the organ or site and its spatial relation-ship with the surrounding nodal stations.

The lymphatic plexuses drain to thefirst echelon lymph nodal stationsthrough precollecting and collectingducts. Sometimes, there are intercalatinglymph nodes in the path of the collectingducts. In general, no intermediate pathsbetween the organ of interest and the firstechelon nodal station have been repre-sented in the atlas to avoid unnecessarycomplexity. However, some clinically rel-evant intercalating nodes have been rep-

resented (superior and inferior rectalnodes and internal pudendal nodes).

The first nodal station reached by thelymphatic drainage of a given organ iscalled the first echelon nodal group. Thefirst echelon lymph nodes connect toeach other through postlymphonodal col-lecting ducts and finally drain to morecentral efferent lymph nodes or directlyinto the venous system through the mainlymphatic trunks, depending on ana-tomic location. As a rule, the first echelonnodal stations for all the different organsof the head and neck, thorax, abdomen,and pelvis are represented. These are listedin the Tables 1–8. One exception to thisrule has been the case of the small boweland most of the large bowel. Due to the

TABLE 2Head and Neck Lymphatic System (II)

Anatomic Site First Echelon Nodal Group Subgroup Category Abbreviation

Floor of mouth Submental nodes Main SMeNSubmandibular nodes Main SMaNInternal jugular nodes Upper, middle Main IJNu, m

Lower gum Submandibular nodes Main SMaNSubmental nodes Main SMeNInternal jugular nodes Upper, middle Main IJNu, m

Upper gum Submandibular nodes Main SMaNRetropharyngeal nodes Main PsRN

Hard palate, soft Internal jugular nodes Upper Main IJNupalate inferior Submandibular nodes Accessory SMaN

Retropharyngeal nodes Accessory PsRNSoft palate, superior Retropharyngeal nodes Main PsRN

Internal jugular nodes Upper Main IJNuTonsil Internal jugular nodes Upper Main IJNuNasopharynx Retropharyngeal nodes Main PsRN

Internal jugular nodes Upper Main IJNuSpinal accessory nodes Main SAN

Pyriform fossa Internal jugular nodes Upper, middle Main IJNu, mPosterior cricoid Internal jugular nodes Upper, middle Main IJNu, mPosterior pharyngeal Retropharyngeal nodes Main PsRN

wall, superior Internal jugular nodes Upper Main IJNuPosterior pharyngeal

wall, inferiorInternal jugular nodes Middle Main IJNm

Supraglottic larynx Internal jugular nodes Upper, middle Main IJNu, mInfraglottic larynx Internal jugular nodes Middle, lower Main IJNm, l

Cervical pretracheal nodes Cervical Main CPNPrelaryngeal nodes Main PLN

Trachea Cervical pretracheal nodes Cervical Main CPNCervical paratracheal nodes Cervical Main LCP, RCPPrelaryngeal nodes Accessory PLN

Thyroid Cervical pretracheal nodes Cervical Main CPNCervical paratracheal nodes Cervical Main LCP, RCPInternal jugular nodes Upper, middle,

lowerMain IJNu, m, l

Retropharyngeal nodes Accessory PsRNParotid gland Parotid nodes Main PG&N

Submandibular nodes Main SMaNSubmandibular gland Submandibular nodes Main SMaN

Internal jugular nodes Upper Main IJNuSublingual gland Submandibular nodes Main SMaN

Internal jugular nodes Upper Main IJNu

818 • Radiology • June 1999 Martinez-Monge et al

Figure 2. CT images depict head and neck nodal stations at the levels hn10 through hn18 on the topogram in Figure 7.

Volume 211 • Number 3 Cross-sectional Nodal Atlas for Definition of Clinical Target Volumes • 819

anatomic mobility of these organs, theefferent pre- and paraaortic nodal groups(fixed structures with reproducible loca-tion), rather than the first echelon nodalgroups (juxtaintestinal and paracolic), arerepresented in the atlas. Patterns ofanomalous nodal spread, such as retro-grade spread, are not shown in this atlas.

ERRORS IN LOCALIZATIONOF NODAL STATIONS

Lymphography is the technique of choiceto visualize nodal groups. However, itsdecline in the field of diagnostic radiol-

ogy has led to the decline of its use as atool for radiation therapy planning, andit has been virtually abandoned for bothpurposes. However, currently used stan-dard radiation ports still follow the bound-aries determined during the lympho-graphic era. During standard simulation,the different nodal stations are not actu-ally seen on the simulation radiographs;therefore, a margin of normal tissue istaken around the CTV to allow for anylocalization uncertainties. Three-dimen-sional virtual clinical target definition,like standard simulation, lacks visualiza-tion of nodal stations. However, becauselocalization errors on cross-sectional im-

ages are minimized (as are the associatedincreases in CTV uncertainty and size ofthe planning taget volume), this problemis not as great. During 3D virtual clinicaltarget definition, only a few of the nodalstations represented in the atlas are vis-ible on a CT image. So, the exact locationof a given station in an individual isdifficult to determine. Furthermore, theinternal structure of the lymphatic sys-tem (different normal variants amongsubjects) precludes any categorical state-ment (2–4). Therefore, we chose to out-line wide areas rather than discrete loca-tions for each nodal station to accountfor the differences in normal anatomic

TABLE 3Thoracic Lymphatic System

Anatomic Site First Echelon Nodal Group Subgroup Category Abbreviation

Lung; RUL antero-medial

Right paratracheal nodes Upper, lower Main RUP, RLP

Lung; RUL postero-lateral, RML, RLLsuperior

Right paratracheal nodesRight hilar nodesSubcarinal nodes

Upper, lower MainMainMain

RUP, RLPPHNrSCN

Lung; RLL inferior Right hilar nodes Main PHNrSubcarinal nodes Main SCN

Lung; LUL superior Left upper paratrachealnodes

Main LUP

Prevascular nodes Main PVsNAortopulmonary window

nodesMain APWN

Lung; LUL inferior,LLL superior, LLLmiddle

Left upper paratrachealnodes

Prevascular nodesAortopulmonary window

nodesLeft hilar nodesSubcarinal nodes

MainMainMainMainMain

LUPPVsNAPWNPHNlSCN

Lung, LLL inferior Left hilar nodes Main PHNlSubcarinal nodes Main SCN

Costal pleura, Supraclavicular nodes Main SclNsuperior Internal jugular nodes Lower Main IJNl

Costal pleura, Juxtavertebral nodes Any level Main JVNs, m, imiddle Internal mammary nodes Any level Main IMNs, m, i

Costal pleura, Axillary nodes Main AxNinferior Juxtavertebral nodes Any level Main JVNs, , m, i

Internal mammary nodes Any level Main IMNs, m, iRight diaphragm, Diaphragmatic nodes Right lateral Main DNlat

subperitoneal Retroaortic nodes Suprarenal, thoracic Main RANsr, tLeft diaphragm, Paraesophageal nodes Inferior Main PENi

subperitoneal Retroaortic nodes Suprarenal, thoracic Main RANsr, tRight and left dia-

phragm, sub-pleural

Diaphragmatic nodesParaesophageal nodesRetroaortic nodes

Anterior, lateralInferiorSuprarenal

MainMainMain

DNa, latPENiRANsr

Breast Axillary nodes Main AxNInternal mammary nodes Any level Main IMNs, m, iSupraclavicular nodes Accessory SclNPectoral nodes Accessory PecN

820 • Radiology • June 1999 Martinez-Monge et al

Figure 3. CT images depict the nodal stations in the thorax (th).

Volume 211 • Number 3 Cross-sectional Nodal Atlas for Definition of Clinical Target Volumes • 821

TABLE 4Gastrointestinal Lymphatic System (I)

Anatomic Site First Echelon Nodal Group Subgroup Category Abbreviation

Gastric cardia Left gastric nodes Juxtacardiac Main LGNcGastric lesser cur- Left gastric nodes Gastropancreatic Main LGNlc

vature Lesser curvature Main LGNlcGastric antrum Hepatic nodes Right gastroepiploic Main HNrg

and pylorus Infrapyloric Main HNpSuprapyloric Main HNp

Greater omentum Hepatic nodes Right gastroepiploic Main HNrgInfrapyloric Main HNpSuprapyloric Main HNp

Gastric greatercurvature

Splenic nodes Suprapancreatic Main SplNs

Duodenum Hepatic nodes Infrapyloric Main HNpRetropyloric Main HNpPancreaticoduodenal Main HNpd

Superior mesenteric nodes Postpancreaticoduodenal Main SMNPancreas Hepatic nodes Infrapyloric, suprapyloric Main HNp

Pancreaticoduodenal Main HNpdHepatic artery Main HNha

Splenic nodes Suprapancreatic Main SplNsSplenic hilum Main SplNh

Left gastric nodes Gastropancreatic Main LGNlcSuperior mesenteric nodes Root of mesentery Main SMN

Middle colic Main SMNPostpancreaticoduodenal Main SMN

Right paraaortic nodes Superior Main RPNsLeft paraaortic nodes Superior Main LPNs

Spleen Splenic nodes Splenic hilum Main SplNhLiver Hepatic nodes Gallbladder, hepatic artery Main HNha

Celiac axis nodes Main CNLeft gastric nodes Lesser curvature Main LGNlcDiaphragmatic nodes Anterior, lateral Main DNa, latParaesophageal nodes Inferior Main PENiRenal hilum nodes Main RRH, LRH

Gallbladder and Hepatic nodes Gallbladder Main HNhacystic duct Foramen of Winslow Main HNha

Hepatic duct Hepatic nodes Foramen of Winslow Main HNhaCommon bile

ductHepatic nodes Foramen of Winslow Main HNha

Postpancreaticoduodenal Main HNpd

TABLE 5Gastrointestinal Lymphatic System (II)

Anatomic Site Efferent Nodal Group* Subgroup Category Abbreviation

Jejunum, ileum Superior mesenteric nodes Main SMNCecum and appendix Superior mesenteric nodes Main SMNAscending colon Superior mesenteric nodes Main SMNTransverse colon, right Superior mesenteric nodes Main SMNTransverse colon, left Superior mesenteric nodes Main SMNDescending colon Left paraaortic nodes Any level Main LPNsr, s, m, i,

LRHSuperior mesenteric nodes Main SMN

Sigmoid colon Preaortic nodes Inferior mesenteric Main PANs, mLeft paraaortic nodes Superior, middle Main LPNs, m

Rectum Preaortic nodes Inferior mesenteric Main PANs, mInternal iliac nodes Accessory IINSacral nodes Accessory SN

* In the small and large intestine, the first echelon nodal group is represented by the juxtaintestinal(small-bowel) or paracolic (large-bowel) nodes located in the mesenteric border of the organ.Because of the mobility of these organs, the efferent nodal groups (fixed structures withreproducible location), rather than the first echelon nodal groups, are represented in the atlas.

822 • Radiology • June 1999 Martinez-Monge et al

variability and nodal interconnection. An-other difficult problem is the mobility ofthe nodal stations located proximally inthe limbs (inguinal, axilla). The locationof these nodal groups will vary greatly,depending on simulation positioning. Thecross-sectional images provided in thisatlas were taken during standard CT posi-tioning and may differ from images takenfor radiation planning in special posi-tions. The topograms with bone land-marks may help in correlating the crosssections provided in this atlas with thereference points of the actual patients.

SYSTEMATIC VERSUSNONSYSTEMATIC DESCRIPTION

This atlas is strongly biased toward theradiation oncology standpoint. Somenodal areas have been arbitrarily dis-carded because they are rarely relevant inradiation oncology. We elected to ignorethe distal and intermediate nodal stationsof the extremities and the nodal stationsof muscular groups. Tumors that spreadto these nodal stations represent a verysmall percentage of the overall clinicalpractice in radiation oncology. We also

chose not to represent lymph nodal sta-tions pertaining to mobile structures (mes-enteric nodes of the small bowel andmost of the large bowel) because of spa-tial unpredictability. For these anatomiclocations, only the efferent pre- and para-aortic nodal groups have been repre-sented.

ATLAS LIMITATIONS

This atlas cannot be used as a tool todiagnose or predict nodal involvement. It

Figure 4. CT images depict the nodal stations in the abdomen (ab).

Volume 211 • Number 3 Cross-sectional Nodal Atlas for Definition of Clinical Target Volumes • 823

only provides a guide to the general ana-tomic pathways of nodal drainage of thenormal organs shown. It cannot helpforecast individual spread patterns. Whenused for 3D virtual clinical target defini-tion, this nodal atlas can help in accu-rately defining the location of the differ-ent nodal stations that are to be includedin the CTV. Deciding which nodal sta-tions should be included in the CTVdepends on the level of spread probabil-ity that is clinically assumable for thatspecific disease manifestation and thenormal tissue complication probabilityfor that intended dose level. These twoissues are a matter of clinical judgmentthat is beyond the general purpose of thisatlas.

POTENTIAL ADVANTAGES

A nodal atlas allows systematic definitionof CTVs in those clinical situations inwhich the irradiation of nodal areas isclinically relevant, which may facilitatereliable intercommunication among insti-tutions. The current tendency, however,is to define CTVs on a nonanatomic basis,probably due to the lack of a commonanatomic language. Some ongoing radia-tion therapy protocols have elected todefine the corresponding CTVs as a vol-ume around the GTV. The CTV is thendefined mathematically as a marginaround the GTV. Although reproducibleamong institutions, this definition car-ries the important risk of including in theCTV some areas with a minimal probabil-ity of tumor involvement or areas thatmay be at higher risk for treatment toxic-ity. A nodal atlas allows a better spatialunderstanding of the valuable informa-tion contained in the surgical pathologyreports. For those patients undergoingpostoperative radiation therapy, the deci-sion-making process essentially dependson the surgical findings. Improving theability to locate high-risk areas (as de-fined by the surgical information) on across-sectional image must necessarily im-prove the quality in treatment planningand delivery. We are currently evaluatingthe potential for redesigning radiationplans on the basis of nodal informationfrom surgical series and 3D reconstruc-tion with the aid of this atlas.

TABLE 6Lymphatic System of the Urinary Tract

Anatomic Site First Echelon Nodal Group Subgroup Category Abbreviation

Right perirenal Interaortic nodes Superior Main RANstissue Preaortic nodes Superior Accessory PANs

Left perirenal Left paraaortic nodes Superior Main LPNstissue Preaortic nodes Superior Accessory PANs

Right kidney Right renal hilum nodes Main RRHRetroaortic nodes Superior Main RANs

Left kidney Left renal hilum nodes Main LRHLeft paraaortic nodes Superior Main LPNs

Suprarenal glands Renal hilum nodes Main RRH, LRHParaaortic nodes Suprarenal Main LPNsr, RPNsrJuxtavertebral nodes Inferior Accessory JVNiParaesophageal nodes Inferior Accessory PENi

Ureter, superior Paraaortic nodes Superior Main RPNs, LPNssegment Common iliac nodes Accessory CIN

External iliac nodes Any level (central, medial) Accessory EINs, m, i(c, m)Ureter, middle Paraaortic nodes Middle Main RPNm, LPNm

segment Common iliac nodes Main CINUreter, inferior Common iliac nodes Main CIN

segment External iliac nodes Any level (central, medial) Main EINs, m, i(c, m)Internal iliac nodes Main IIN

Bladder External iliac nodes Any level (central, medial) Main EINs, m, i(c, m)Internal iliac nodes Accessory IINCommon iliac nodes Accessory CIN

Bulbomembranousurethra

External iliac nodes Middle, inferior (medial) Main EINm, i(m)

TABLE 7Lymphatic System of the Male Genital Organs

Anatomic Site First Echelon Nodal Group Subgroup Category Abbreviation

Scrotum Superficial inguinal nodes Any level Main INs, i(m, l)Perineum Superficial inguinal nodes Inferior (medial) Main INi(m)Penis, skin Superficial inguinal nodes Superior (medial) Main INs(m)Penis, glans Superficial inguinal nodes Superior (medial) Main INs(m)

Deep inguinal nodes Main INs, i(d)External iliac nodes Inferior (medial) Accessory EINi(m)Internal iliac nodes Accessory IIN

Penis, corpora cav-ernosa/penileurethra

Superficial inguinal nodes Superior (medial) Main INs(m)

Right testicle/epi-didymis

Right paraaortic nodes Superior, middle,inferior

Main RPNs, m, i

Preaortic nodes Superior, middle,inferior

Main PANs, m, i

External iliac nodes Any level (central) Accessory EINs, m, i(c)Left testicle/epi- Left renal hilum nodes Main LRH

didymis Left paraortic nodes Superior Main LPNsPreaortic nodes Superior, middle,

inferiorAccessory PANs, m, i

External iliac nodes Any level (central) Accessory EINs, m, i(c)Ductus deferens External iliac nodes Superior, middle

(central), inferior(central, lateral)

Main EINs, m(c), i(c, l)

Internal iliac nodes Main IINSeminal vesicles External iliac nodes Any level (medial,

central)Main EINs, m, i(m, c)

Internal iliac nodes Main IINProstate/prostatic

urethraExternal iliac nodes Any level (central) Main EINs, m, i(c)

Internal iliac nodes Main IINSacral nodes Main SN

824 • Radiology • June 1999 Martinez-Monge et al

Figure 5. CT images depict the nodal stations in the male pelvis (mp).

Volume 211 • Number 3 Cross-sectional Nodal Atlas for Definition of Clinical Target Volumes • 825

Figure 6. CT images depict the nodal stations in the female pelvis (fp).

826 • Radiology • June 1999 Martinez-Monge et al

Figure 7. Topograms show the levels to which the CT images in Figures 1–6 correspond.

Volume 211 • Number 3 Cross-sectional Nodal Atlas for Definition of Clinical Target Volumes • 827

Finally, the atlas-based 3D definition ofCTVs has the potential to improve the

therapeutic ratio. Nodal groups with avery low probability of metastatic involve-

ment can be excluded from the CTV, thusexpanding beam arrangement possibili-ties and allowing increased treatment in-tensity. We are also currently evaluatingthe volumetric implications (normal tis-sue dose-volume histograms) of using 3Dvirtual simulation with either a nodalatlas or standard bone landmarks.

The present atlas should aid the radia-tion oncologist in accurately locating oncross-sectional images the different nodalstations that will correspond to the cho-sen clinical target volume.

Acknowledgments: The authors thank JohnCroyle for his help in the preparation of thegraphic matrix of the illustrations and DavidCarpenter for editorial assistance.

References1. International Commission on Radiation

Units and Measurements. Prescribing, re-cording and reporting photon beamtherapy. ICRU Report 50. Washington, DC:International Commission on RadiationUnits and Measurements, 1993.

2. Rouviere H. Anatomy of the human lym-phatic system. Ann Arbor, Mich: Edwards,1938.

3. Donini I, Battezatti M. The lymphatic sys-tem. Padua, Italy and London, England:Piccin Medical Books, 1972.

4. Uflacker R. Atlas of vascular anatomy. Balti-more, Md: Williams & Wilkins, 1997.

5. American Joint Committee on Cancer.AJCC cancer staging manual. 5th ed. Phila-delphia, Pa: Lippincott-Raven, 1997.

6. Ellis H, Logan B, Dixon A. Human crosssectional anatomy. Oxford, England: But-terworth-Heinemann, 1991.

TABLE 8Gynecologic Lymphatic System

Anatomic Site First Echelon Nodal Group Subgroup Category Abbreviation

Right ovary Right paraaortic nodes Superior, middle,inferior

Main RPNs, m, i

External iliac nodes Superior (central) Accessory EINs(c)Left ovary Left renal hilum Main LRH

Left paraaortic nodes Superior Main LPNsPreaortic nodes Superior Main PANsExternal iliac nodes Any level (central) Accessory EINs, m, i(c)

Right fallopian tube Right paraaortic nodes Inferior Main RPNiExternal iliac nodes Superior (central) Accessory EINs(c)Internal iliac nodes Accessory IIN

Left fallopian tube Left paraaortic nodes Superior Main LPNsExternal iliac chain Superior (central) Accessory EINs(c)Internal iliac nodes Accessory IIN

Cervix uteri External iliac nodes Superior, middle(medial, central)

Main EINs, m(m, c)

Internal iliac nodes Main IINSacral nodes Main SN

Corpus uteri Right paraaortic nodes Inferior Main RPNiPreaortic nodes Middle Main PANmLeft paraaortic nodes Middle Main LPNmExternal iliac nodes Superior (central) Accessory EINs(c)Superficial inguinal nodes Superior (medial) Accessory INs(m)

Vagina External iliac nodes Any level (central,medial)

Main EINs, m, i(c, m)

Internal iliac nodes Main IINSacral nodes Accessory SN

Vulva Superficial inguinal nodes Superior (medial) Main INs(m)Clitoris Superficial inguinal nodes Any level Main INs, i(m, l)

Deep inguinal nodes Main INs, i(d)Greater vestibular

glandsSuperficial inguinal nodes Superior (medial) Main INs(m)

828 • Radiology • June 1999 Martinez-Monge et al