Delineation of the neck node levels for head and neck tumors : A 2013 update.

Veincent Gregoire, Kian Ang, Wilfried Budach, et al

Park Haryung

2015-06-19

Introduction• In head and neck IMRT, it has been shown that heterogeneity in target volume selec-

tion and delineation is an important source of variations among radiation oncologist.

• In previous framework– Not all the neck node areas described in the TNM atlas were included– Description of the anatomic boundaries of some of levels(e.g. in the lower neck) was not suffi-

ciently accurate and required some interpretation for the users– Guidelines for the node into normal structures to generate the CTV was both arbitrary and po-

tentially imprecise • New data on tumor extra-capsular extension in lymph nodes have emerged permitting specific

recommendations to be proposed– Illustrations of nodal levels were not available in DICOM or DICOM-RT format

• consequently limiting the easy use of the atlas and preventing its direct importation into treat-ment planning systems.

• In this context, update the previously published guidelines on target delineation in the neck– Consensus guidelines for the delineation of the neck node levels

The consensus guidelines• Level Ia

– median region located between the anterior belly of the digastric muscles, which contains the submental nodes

– Level Ia is at greatest risk of harboring metastases from cancer arising from the floor of the mouth, the anterior oral tongue, the anterior mandibular alveolar ridge, and the lower lip

Level Cranial Caudal Anterior Posterior Lateral Medial

Level Ia

Mylo-hyoid m. Platysma m. Symphysis menti

Body of hyoid bone/mylo-hy-

oid m.

Medial edge of ant. belly of digastric m.

n.a.

The consensus guidelines• Level Ib

– Level Ib contains the submandibular nodes located in the space between the inner side of the mandible laterally and the digastric muscle medially, from the symphysis menti anteriorly to the submandibular gland posteriorly.

– Nodes in level Ib are at risk of developing metastases from cancers of the oral cavity, anterior nasal cavity, soft tissue structures of the mid-face and the submandibular gland.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level Ib

Cranial edge of submandibular gland; anteri-orly, mylo-hy-oid m.

caudal edge of hyoid bone and caudal edge of mandible; caudal edge ofsubmandibular gland

Symphysis menti

Posterior edge of submandibu-lar gland (cau-dally)/posterior belly of digas-tric m. (cra-nially)

Medial aspect (innerside) of mandible down to caudal edge/platysma m. (caudal)/medial tery-goid m. (poste-riorly)

Lateral edge of ant. belly of di-gastric m. (caudally)/posterior belly of digastric m. (cranially)

The consensus guidelines• Level II

– Level II (Table 3) contains the upper jugular nodes located around the upper one-third of the in-ternal jugular vein (IJV) and the upper spinal accessory nerve (SAN).

– The nodes in level II are therefore at greatest risk of harboring metastases from cancers of the nasal cavity, oral cavity, nasopharynx, oropharynx, hypopharynx, larynx, and the major sali-vary glands.

– Level IIb is more likely associated with primary tumors of the oropharynx or nasopharynx, and less frequently with tumors of the oral cavity, larynx or hypopharynx.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level II

Caudal edge of the lateral ro-cess of C1

Caudal edge of the body of the hyoid bone

Posterior edge of thesubmandibulargland/posterior edge of poste-rior belly of di-gastric m.

Posterior edge of sternoclei-domastoid m.

Deep (medial)surface ofSternocleido-mastoid m./platysma m./parotid gland/posterior belly of digastric m.

Medial edge ofinternal carotidArtery/scalenius m.

The consensus guidelines• Level III

– Level III (Table 3) contains the middle jugular nodes located around the middle third of the IJV. • It is the caudal extension of level II. • It extends from the caudal edge of the body of the hyoid bone to the caudal edge of the cricoid

cartilage

– Nodes in level III are at greatest risk of harboring metastases from cancers of the oral cavity, nasopharynx, oropharynx, hypopharynx and larynx.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level III

Caudal edge of the body of the hyoid Bone

Caudal edge of cricoid carti-lage

Anterior edge ofSternocleido-mastoid m./posterior third of thyro-hyoid m.

Posterior edge ofsternocleido-mastoid m.

Deep (medial)surface of ster-nocleidomas-toid m.

Medial edge ofcommon carotidArtery/scalenius mm.

The consensus guidelines• Level IVa

– Level IVa (Table 3) contains the lower jugular lymph nodes located around the inferior third of the IJV from the caudal limit of level III to a limit set arbitrarily 2 cm cranial to the sternoclavic-ular joint, caudally.

– Level IVa nodes are at high risk for harboring metastases from cancers of the hypopharynx, larynx, thyroid and cervical esophagus.

– Rarely metastases from the anterior oral cavity may manifest in this location with minimal or no proximal nodal disease.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level IVa

Caudal edge ofcricoid carti-lage

2 cm cranial to sternal manubrium

Anterior edge ofSternocleido-mastoid m. (cranially)/body ofSternocleido-mastoid m. (caudally)

Posterior edge ofsternocleido-mastoid m. (cranially)/scalenius mm.(caudally)

Deep (medial)surface ofSternocleido-mastoid m. (cranially)/lateral edge ofSternocleido-mastoid m. (caudally)

Medial edge ofcommon carotidArtery/lateral edge of thyroid gland/scalenius mm.(cranially)/medial edge ofSternocleido-mastoid m. (caudally)

The consensus guidelines• Level IVb

– Level IVb (Table 3) contains the medial supraclavicular lymph nodes located in the continuation of level IVa down to the cranial edge of the sternal manubrium.

– Level Ivb nodes are at high risk for harboring metastases from cancers of the hypopharynx, sub-glottic larynx, trachea, thyroid and cervical esophagus.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level IVb

Caudal border oflevel IVa (2 cmcranial to ster-nalmanubrium)

Cranial edge of sternal manubrium

Deep surface ofSternocleido-mastoid m./deep aspect ofclavicle

Anterior edge of scalenius mm. (cranially)/apex of lung, the brachio-ceph-alic vein(right side) and the carotid artery and subclavian artery on the left side (cau-dally)

Lateral edge ofscalenius m.

Lateral border of level VI (pre-tracheal com-ponent)/medial edge of common carotid artery

The consensus guidelines• Level Va and Vb

– Level Va and Vb (Table 4) contains the nodes of the posterior triangle group located posteriorly to the sternocleidomastoid muscle around the lower part of the spinal accessory nerve and the transverse cervical vessels.

– It extends from a plane crossing the cranial edge of the body of the hyoid bone to a plane crossing the cervical transverse vessels caudally.

– level V is currently subdivided into levels Va and Vb using the caudal edge of the cricoid carti-lage as an anatomic landmark.

– Level V lymph nodes are at high risk for harboring metastases from cancers of the nasophar-ynx, oropharynx and thyroid gland.

– Nodes in level V are most often associated with primary cancers of the nasopharynx, the oropharynx, the cutaneous structures of the posterior scalp, and the thyroid gland (level Vb).

The consensus guidelines• Level Va and Vb

– Level Va and Vb (Table 4) contains the nodes of the posterior triangle group located posteriorly to the sternocleidomastoid muscle around the lower part of the spinal accessory nerve and the transverse cervical vessels.

– It extends from a plane crossing the cranial edge of the body of the hyoid bone to a plane crossing the cervical transverse vessels caudally.

– level V is currently subdivided into levels Va and Vb using the caudal edge of the cricoid carti-lage as an anatomic landmark.

– Level V lymph nodes are at high risk for harboring metastases from cancers of the nasophar-ynx, oropharynx and thyroid gland.

– Nodes in level V are most often associated with primary cancers of the nasopharynx, the oropharynx, the cutaneous structures of the posterior scalp, and the thyroid gland (level Vb).

Level Cranial Caudal Anterior Posterior Lateral Medial

Level V

Cranial edge of the body of hy-oid bone

Plane just be-low transverse cervical ves-sels

Posterior edge of sternocleido-mastoid m.

Anterior border of trapezius m.

Platysma m./skin

Levator scapu-lae m./scale-nius m. (cau-dally)

The consensus guidelines• Level Vc

– Level Vc (Table 4) contains the lateral supraclavicular nodes located in the continuation of the posterior triangle nodes (level Va and Vb) from the cervical transverse vessels down to a limit set arbitrarily 2 cm cranial to the sternal manubrium

– Level Vc receives efferent lymphatics from the posterior triangle nodes (level Va and Vb) and is more commonly associated with nasopharyngeal tumors.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level Vc

Plane just be-low transverse ervical vessels (caudal border of level V)

2 cm cranial to sternal anubrium, i.e. caudal border of level Iva

Skin Anterior border of trapezius m. (cranially)/anterior to serratus ante-rior m. (cau-dally)

Trapezius m (cranially)/clav-icle (caudally)

Scalenius m./lateral edge of sternocleido-mastoid m, lat-eral edge of level IVa

The consensus guidelines• Level VIa and VIb

– Level VI (Table 5) contains the anterior compartment nodes including superficially, the anterior jugular nodes (level VIa), and in the deep previsceral space, the pre-laryngeal, pre-tracheal and para-tracheal (recurrent laryngeal nerve) nodes (level VIb)

– These nodes are at high risk for harboring metastases from cancers of the lower lip, the oral cavity (floor of mouth and tip of the tongue), the thyroid gland, the glottic and subglottic lar-ynx, the apex of the piriform sinus, and the cervical esophagus.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level VIa

Caudal edge of the hyoid bone or caudal edge of the sub-mandibular gland, which-ever is more caudal

Cranial edge of the sternal manubrium

Skin/platysma m.

Anterior aspect of the infrahy-oid (strap) mm.

Anterior edges of both stern-ocleidomastoid mm.

n.a.

The consensus guidelines• Level VIa and VIb

– Level VI (Table 5) contains the anterior compartment nodes including superficially, the anterior jugular nodes (level VIa), and in the deep previsceral space, the pre-laryngeal, pre-tracheal and para-tracheal (recurrent laryngeal nerve) nodes (level VIb)

– These nodes are at high risk for harboring metastases from cancers of the lower lip, the oral cavity (floor of mouth and tip of the tongue), the thyroid gland, the glottic and subglottic lar-ynx, the apex of the piriform sinus, and the cervical esophagus.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level VIb

Caudal edge of the thyroid car-tilage

Cranial edge of the sternal manubrium

Posterior aspect of infrahyoid (s-trap) mm.

Anterior aspect of larynx, thy-roid gland and trache (pre-laryngeal and pre-tra-chealnodes)/prever-tebral m. (right side)/esophagus (left side)

Common carotid artery on both sides

Lateral aspect of trachea & esophagus (caudally)

The consensus guidelines• Level VIIa

– Level VIIa (Table 6) contains the retropharyngeal nodes, which lie within the retropharyngeal space, extending cranially from the upper edge of the first cervical vertebrae to the cranial edge of the body of the hyoid bone caudally

– These nodes are at risk of harboring metastases from cancers of the nasopharynx, the poste-rior pharyngeal wall and the oropharynx (mainly the tonsillar fossa and the soft palate).

Level Cranial Caudal Anterior Posterior Lateral Medial

Level VIIa

Upper edge of body of c1/hard palate

Cranial edge of the body of the hyoid bone

Posterior edge of the superior or middle pha-ryngeal con-strictor m.

Longus capitis m. and longus colli m.

Medial edge of the internal carotid artery

A line parallel to the lateral edge of the longus capitis muscle

The consensus guidelines• Level VIIb

– Level VIIb (Table 6) contains the retro-styloid nodes, which are the cranial continuation of the level II nodes.

– They are located in the fatty space around the jugulo-carotid vessels up to the base of skull (jugular foramen).

– Retro-styloid nodes are at risk of harboring metastases from cancers of the nasopharynx, and from any other head and neck primary with massive infiltration of upper level II nodes through retrograde lymph flow.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level VIIb

Base of skull (jugular fora-men)

Caudal edge of the lateral process of C1 (upper limit of level II)

Posterior edge of prestyloid para-pharyn-geal space

Vertebral body of C1, base of skull

Styloid process/deep parotid lobe

Medial edge of the internal carotid artery

The consensus guidelines• Level VIIb

Level Cranial Caudal Anterior Posterior Lateral Medial

Level VIIb

Base of skull (jugular fora-men)

Caudal edge of the lateral process of C1 (upper limit of level II)

Posterior edge of prestyloid para-pharyn-geal space

Vertebral body of C1, base of skull

Styloid process/deep parotid lobe

Medial edge of the internal carotid artery

Retrostyloid Space

Prestyloid Space

The consensus guidelines• Level VIII

– Level VIII (Table 7) contains the parotid node group, which includes the subcutaneous pre-au-ricular nodes, the superficial and deep intraparotid nodes and the subparotid nodes.

– They are at risk of harboring metastasis from cancers of these regions but especially from tu-mors of the frontal and temporal skin, the orbit, the external auditory canal, the nasal cavities, and the parotid gland.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level VIII

Zygomatic arch, external auditory canal

Angle of the mandible

Posterior edge of mandidular ramus & poste-rior edge ofmasseter m. (laterally) me-dial pterygoid muscle (medi-ally)

Anterior edge of sternocleido-mastoid m. (laterally), pos-teriorbelly of digas-tric m. (medi-ally)

SMAS layer in sub-cutaneous tissue

Styloid process and styloid m.

The consensus guidelines• Level IX

– Level IX (Table 8) contains the malar and bucco-facial node group, which includes inconsistent superficial lymph nodes around the facial vessels on the external surface of the buccinator muscle.

– They are at risk of harboring metastases from cancers of the skin of the face, the nose, the maxillary sinus (infiltrating the soft tissue of the cheek) and the buccal mucosa.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level IX

Caudal edge of the orbit

Caudal edge of the mandible

SMAS layer in sub-cutaneous tissue

Anterior edge of masseter m. & corpus adi-posum buccae(bichat’s fat pad)

SMAS layer in sub-cutaneous tissue

Buccinator m.

The consensus guidelines• Level Xa

– Level Xa (Table 9) contains the retroauricular (also called mastoid) and subauricular nodes, which includes superficial nodes lying on the mastoid process from the cranial edge of the ex-ternal auditory canal cranially to the tip of the mastoid caudally

– They are at risk of harboring metastases mainly from skin cancers of the retro-auricular area.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level Xa

Cranial edge of external audi-tory canal)

Tip of the mas-toid

Anterior edge of the mastoid (caudally)/pos-terior edge of the external auditory canal (cranially)

Anterior border of occipital nodes poste-rior edge of sternocleido-mastoid m.

Sub-cutaneous tissue

Splenius capi-tis m. (cau-dally)/temporal bone (cranially)

The consensus guidelines• Level Xb

– Level Xb (Table 9) contains the occipital lymph nodes, which are the cranial and superficial continuation of the level Va nodes up to the cranial protuberance.

– Level Xb nodes receive efferent vessels from the posterior part of the hair-bearing scalp and are at risk of metastases from skin cancers of the occipital area.

Level Cranial Caudal Anterior Posterior Lateral Medial

Level Xb

External occipi-tal protuber-ance

Cranial border of level V

Posterior edge of sternoclei-domastoid m.

Anterior (lat-eral) edge of trapezius m.

Sub-cutaneous tissue

Splenius capitis m.