Neck management and PORT for H&N

Question 1

What is a radical neck dissection?

Answer 1

Radical neck dissection is a procedure that removes all LN levels (“comprehensive”) from levels I–V and other structures (the sternocleidomastoid, jugular vein, and spinal accessory nerve).

Question 2

What is a modified radical neck dissection?

Answer 2

Modified radical neck dissection is a comprehensive nodal dissection that spares at least 1 of the following structures: sternocleidomastoid, jugular vein, or spinal accessory nerve.

Question 3

What is considered a selective neck dissection?

Answer 3

Selective neck dissection is dissection of selective neck areas based on the understanding of the common pathways of spread according to the H&N site.

Question 4

What is a supraomohyoid neck dissection?

Answer 4

Supraomohyoid neck dissection is removal of nodes above the omohyoid muscle (levels I–III and sup V), common for cancers of the OC.

Question 5

What is a lat neck dissection?

Answer 5

Lat neck dissection is selective dissection of levels II–IV, traditionally for cancers of the larynx and pharynx.

Question 6

What is an anterolat neck dissection, and when should it be done?

Answer 6

Anterolat neck dissection is a selective neck dissection of levels I–IV, typically done for cN0 oropharyngeal cancer (OPC).

Question 7

What is an ant neck dissection, and when should it be done?

Answer 7

Ant neck dissection is a selective neck dissection of levels II–IV, typically done for cN0 laryngeal/hypopharyngeal cancers.

Question 8

What is a posterolat neck dissection, and when is it done?

Answer 8

Posterolat neck dissection is a selective neck dissection of the retroauricular, suboccipital, upper jugular, and post cervical nodes. It is commonly used for skin cancers (SCC, melanoma) located post to the ear
canal.

Question 9

What is an ant compartment dissection, and when is it done?

Answer 9

Ant compartment dissection is a selective level VI dissection, traditionally performed for thyroid cancers.

Question 10

Which 3 H&N sites have the highest rates of clinical nodal positivity?

Answer 10

The NPX (87%), base of tongue (78%), and tonsil (76%) have the highest rates of clinical nodal positivity. (Lindberg R et al., Cancer 1972)

Question 11

Which 2 H&N sites have the highest rates of radiographic retropharyngeal nodal positivity?

Answer 11

On CT/MRI, nasopharyngeal and pharyngeal wall primaries have the highest rates of retropharyngeal involvement (74% and 20%, respectively). (McLaughlin MP et al., Head Neck 1995)

Question 12

Which tumor sites have the highest rates of bilat lymphatic drainage?

Answer 12

Base of tongue, floor of mouth, soft palate, supraglottic larynx, any tumors at or approaching midline.

Question 13

Which tumor sites should undergo contralat submandibular dissection?

Answer 13

Ant tongue, floor of mouth, or lip that crosses or approaches midline.

Question 14

When is a selective neck dissection appropriate?

Answer 14

When there is a clinically negative neck with an estimated ≥10% risk of subclinical Dz; otherwise, a (therapeutic) modified radical neck dissection is
indicated. Rarely is a radical neck dissection done anymore).

Question 15

What is the role of SLNB in the management of oral cavity (OC) tumors?

Answer 15

It is an alternative to elective neck dissection for T1 or T2 OC tumors (per NCCN 2018).

Question 16

Per NCCN 2018, what type of neck dissection should N0, N1–N2c and N3 necks undergo?

Answer 16

N0: Selective neck dissection (OC at least levels I–III, OPX at least levels II– IV, hypopharynx at least levels II–IV and level VI, when appropriate)
N1–N2c: Selective or comprehensive neck dissection (controversial)
N3: comprehensive or radical neck dissection.

Question 17

When is an elective neck dissection necessary after definitive RT?

Answer 17

Elective neck dissection is necessary whenever there is a PR/residual Dz after RT (any nodal stage).

Question 18

When can an elective neck dissection be omitted for a pt with N2–N3 Dz?

Answer 18

This is controversial. The decision may be guided by PET response 12 wks after RT. If a metabolic CR and node <1 cm, elective neck dissection may be
omitted. However, at some institutions, any pt with ≥N2 Dz undergoes an elective neck dissection regardless of the response to RT. The utilization of elective neck dissection in the absence of evidence for residual Dz after RT is increasingly less common.

Question 19

What are the indications for adj RT after a neck dissection?

Answer 19

After a neck dissection, adj RT should be offered to pts with ≥3 cm +nodes, ≥2 +nodes, if ≥2 nodal levels are involved, with +ECE, or if there is an undissected high-risk nodal area.

Question 20

When should chemo be added to PORT in the management of H&N cancers?

Answer 20

Absolute indications: +margin, +ECE (category 1 per the NCCN)
Relative (weaker) indications: multiple +nodes, PNI/LVI, T4a primary, or OC primary with level IV nodes

Question 21

How should cisplatin be dosed when given with RT for H&N cancers?

Answer 21

The cisplatin dosing with RT is 100 mg/m2 intravenously on days 1, 22, and 43.

Question 22

How did the 2 seminal H&N trials supporting the addition of chemo to RT in the adj setting differ, and what did they show?

Answer 22

EORTC 22931 (Bernier J et al., NEJM 2004): 334 pts randomized to PORT 66 Gy vs. PORT + cisplatin 100 mg/m2 on days 1, 22, and 43. Eligibility: ECE, +margin, PNI, LVI, and levels 4–5 +N from OC cancer/OPC. There
was better OS, DFS, and 5-yr LC with CRT but ↑ grades 3–4 toxicity.

RTOG 95–01 (Cooper JS et al., NEJM 2004): 459 pts randomized to 60–66 PORT vs. PORT + cisplatin 100 mg/m2 on days 1, 22, and 43. Eligibility: >2 LNs, ECE, +margin. There was better DFS (43% vs. 54%) and 2-yr
LRC (72% vs. 82%) but only a trend to improvement in OS (57% vs. 63%).

Question 23

What are the presumed reasons why EORTC 22931 showed an OS benefit while RTOG 9501 did not?

Answer 23

The EORTC trial included more margin+ pts (28% vs. 18%), more pts with worse tumor differentiation (19% vs. 7%), more hypopharynx cases (20% vs. 10%), and more pts that started RT ≥6 wks after Sg (32%).

Question 24

What important study compared preop RT to PORT for advanced H&N (mostly hypopharyngeal) cancers?

Answer 24

RTOG 73–03 (Tupchong L et al., IJROBP 1991): 354 pts, 50 Gy preop vs. 50–60 Gy postop. LC improved with PORT but not OS. Both LC and OS improved with PORT in OPC pts.

Question 25

What are the indications for boosting the tracheostomy stoma with PORT?

Answer 25

Indications for boosting the stoma with PORT are:

1. Emergency tracheostomy/tracheostomy prior to definitive Sg if close to tumor
2. Subglottic extension
3. Ant ST extension
4. T4 laryngeal tumors

Question 26

What are the dose recommendations for PORT to the neck and primary?

Answer 26

In 2 Gy/fx: 50–54 Gy: undissected clinically negative area, 60 Gy: postop (–margin) and dissected neck, 66 Gy: postop (+margin, +ECE), 70 Gy: gross residual

Question 27

When should the retropharyngeal nodes be covered/irradiated?

Answer 27

Nasopharyngeal, hypopharyngeal, and pharyngeal wall primaries or N2 or greater Dz all merit prophylactic irradiation of the lat retropharyngeal nodes (anything with “pharynx”).

Question 28

What are the indications for treating the sup mediastinal nodes in H&N cancer?

Answer 28

T3–T4, hypopharyngeal/thyroid primaries, and involvement of the SCV nodes are indications for treating the sup mediastinal nodes

Question 29

What is the inf extent of the RT fields if sup mediastinal nodes are to be treated?

Answer 29

The inf extent encompasses nodes to the level of the carina or 5 cm below the clavicular heads.

Question 30

What are some contraindications to neck dissection as the primary management of the neck in pts with H&N cancers?

Answer 30

Base of skull invasion, satellite skin nodules/dermal invasion, and medically unstable/inoperable pts. Relative contraindications include internal carotid invasion, bone invasion, and skin ulceration.

Question 31

What did the TROG 98.02 study suggest regarding the utility of planned neck dissections after definitive CRT for H&N cancer?

Answer 31

TROG 98.02 determined that neck dissection may not be needed for N2–N3 pts who have a CR on PET 12 wks post-CRT. These pts have low rates (4%–6%) of LRF despite the omission of neck dissection. (Corry J et al., Head Neck 2008)

Question 32

What are some common late sequelae of RT (+/- neck dissection) in H&N cancer?

Answer 32

Neck fibrosis/scarring, submental edema, hypothyroidism, and xerostomia

Question 33

According to the RTOG combinatorial analysis, what factors were associated with severe late toxicity after CRT in advanced H&N cancer pts?

Answer 33

Per the RTOG combinatorial analysis, advanced age, advanced T stage, laryngeal/hypopharyngeal primaries, and neck dissection were all associated with severe late sequelae after CRT. (Machtay M et al., JCO 2008)