Sinonasal/paranasal sinus

Question 1

What is the incidence of sinonasal/paranasal sinus (PNS) tumors in the United States?

Answer 1

∼2,000 cases/yr (<1% of all tumors). 3% of H&N cancers.

Question 2

Is there a sex predilection for sinonasal/PNS tumors?

Answer 2

Yes. Males are more commonly affected than females (2:1).

Question 3

Sinonasal/PNS tumors are more common in what continents?

Answer 3

PNS tumors are more prevalent in Asia and Africa.

Question 4

What histologies are typically seen with sinonasal/PNS tumors?

Answer 4

Squamous (50%), adenocarcinoma, adenoid cystic, melanoma, esthesioneuroblastoma (ENB), sinonasal undifferentiated carcinoma (SNUC), small cell, sarcoma (RMS), lymphoma, plasmacytoma, and mets.

Question 5

What nonmalignant entities present as a mass in the PNS or the nasal cavity?

Answer 5

Sinonasal polyposis, choanal polyps, and juvenile angiofibromas.

Question 6

What sinuses make up the PNS?

Answer 6

The frontal, ethmoid, sphenoid, and maxillary sinuses make up the PNS.

Question 7

What structures border the maxillary sinus?

Answer 7

Anterior: facial bone
Anterolateral: zygomatic arch
Posterolateral: infratemporal fossa
Posterior: pterygopalatine fossa
Superior: orbital floor
Inferior: hard palate
Medial: nasal cavity

Question 8

What is the name for the thin bone in the medial wall of the orbit that is prone to erosion/breakthrough by ethmoid tumors?

Answer 8

The thin bone of the medial orbital wall is called the lamina papyracea.

Question 9

What is the local invasion pattern of ethmoid tumors?

Answer 9

Superiorly through the cribriform plate to the ant cranial fossa or medially through the lamina papyracea into the orbit.

Question 10

Which is the most common sinus/site of origin for PNS tumors?

Answer 10

The maxillary sinus is the most commonly involved sinus/site for PNS tumors (70%–80%).

Question 11

What is the most common site for ENB?

Answer 11

The nasal cavity.

Question 12

What environmental exposures are associated with the development of sinonasal/PNS tumors?

Answer 12

Industrial fumes, wood dust, nickel, chromium, hydrocarbons, formaldehyde, nitrogen mustard, air pollution. They have also been linked to HPV and EBV.

Question 13

What are some presenting Sx of sinonasal/PNS tumors?

Answer 13

Facial pain, nasal obstruction, nasal discharge, epistaxis, sinus obstruction, trismus (pterygoid involvement), ocular deficits (diplopia, blurry vision), facial pain d/t trigeminal neuralgia, midfacial hypesthesia from impingement of the infraorbital branch of CN V2, palatal mass/erosion, and otalgia.

Question 14

What is the basic workup for sinonasal/PNS tumors?

Answer 14

PNS tumor workup: H&P w/ nasal endoscopy and Bx, labs, CT/MRI head/neck, CT chest, PET if stage III/IV, dental consult if required (per NCCN, 2018).

Question 15

Describe the T staging of maxillary tumors per the latest AJCC (8th edition, 2017) classification.

Answer 15

T1: confined to sinus, no bone erosion
T2: bone erosion w/o involvement of post wall of max sinus or pterygoid
T3: invades post wall of max sinus, SQ tissues, pterygoid fossa, floor/medial
wall of orbit, or ethmoid sinus
T4a: invades ant orbital structures, skin of cheek, pterygoid plate,
infratemporal fossa, cribriform plate, sphenoid or frontal sinus
T4b: invades orbital apex, NPX, clivus, intracranial extension, CN
involvement (except V2), dura, brain

Question 16

Describe the T staging of nasal cavity/ethmoid tumors per the latest AJCC (8th edition, 2017) classification.

Answer 16

T1: confined to 1 subsite, w/ or w/o bone invasion
T2: invades 2 subsites in a single region or extending to involve an adjacent region w/ in the nasoethmoidal complex, w/ or w/o bone invasion
T3: invades medial wall or floor of orbit, maxillary sinus, palate, or cribriform plate
T4a: invades ant orbital contents, skin of nose or cheek, min extension to ant cranial fossa, pterygoid plates, sphenoid, or frontal sinuses
T4b: invades orbital apex, dura, brain, middle cranial fossa, cranial nerves other than V2, NPX, or clivus

Question 17

How are the nodes staged for sinonasal/PNS tumors?

Answer 17

N1: single ipsi ≤3 cm and ENE–
N2a: single ipsi >3 and ≤6 cm and ENE– or single ipsi/contralat node ≤3 cm and ECE+
N2b: multiple ipsi nodes ≤6 cm and ENE–
N2c: bilat or contralat ≤6 cm and ENE–
N3a: node >6 cm and ENE–
N3b: single ipsi node >3 cm and ENE+ or multiple ipsi/contra/bilat nodes, any with ENE+

Question 18

How are the overall sinonasal/PNS stage groups broken down (based on TNM)?

Answer 18

Stage I: T1N0
Stage II: T2N0
Stage III: T3N0 or T1–3N1
Stage IVA: T4aN0–1 or T1–4aN2
Stage IVB: T4b or N3
Stage IVC: M1

Question 19

What is Ohngren line, and why is it important?

Answer 19

The Ohngren line is a theoretic plane that extends from the medial canthus of the eye to the angle of the mandible. Tumors superoposterior to this line
have deeper invasion, with many being unresectable (d/t invasion of the orbit, ethmoids, and pterygopalatine fossa). The relationship of a tumor to Ohngren
line was an important prognostic factor, but with CT, MRI, and PET for imaging tumors, the significance of this line is principally historic.

Question 20

For sinonasal/PNS tumors, what factors predict for nodal mets?

Answer 20

Neck nodal involvement is uncommon at Dx except when tumors have progressed to involve the mucosal surfaces (i.e., oral cavity, maxillary gingiva, or gingivobuccal sulcus). Histology is also predictive; squamous and undifferentiated tumors most commonly present with nodes, while nodal Dz is very uncommon with adenoid cystic and adenocarcinomas.

Question 21

What neck node groups are generally involved with sinonasal/PNS tumors?

Answer 21

Retropharyngeal (1st echelon), Level Ib, II, and periparotid nodes are most commonly involved.

Question 22

What subsite of PNS tumors has the highest rate of nodal mets?

Answer 22

Maxillary sinus tumors have the highest rate of nodal mets (10%–15%) of all PNS tumors.

Question 23

What is the 5-yr OS rate for maxillary/ethmoid sinus tumors (all stages)?

Answer 23

∼45%

Question 24

What is the 5-yr OS rate for N+ maxillary and ethmoid sinus tumors?

Answer 24

Maxillary: ∼15%, Ethmoid: 0%

Question 25

What is the overall LC rate for sinonasal/PNS tumors?

Answer 25

50%–60%

Question 26

How are sinonasal/PNS tumors typically managed?

Answer 26

Surgical resection and adj RT +/- chemo. Consider induction chemo in SNUCs, small cell, sinonasal neuroendocrine tumors, very advanced primary
squamous carcinomas.

Question 27

Are there any RCTs that define Tx for sinonasal/PNS tumors?

Answer 27

No. Dz is rare and presents at multiple sites with varying histologies. It would be difficult to appropriately power an RCT.

Question 28

What type of Sg is necessary to manage a maxillary sinus tumor?

Answer 28

Partial (2 walls of maxilla removed) or total maxillectomy to –margins. For smaller tumors, endoscopic sinus surgery, with or without robotic assistance, is replacing open procedures. For larger medial tumors, a medial
maxillectomy with a midfacial degloving technique is performed with an incision made under the lip (Caldwell–Luc). For tumors that are mainly inf,
an infrastructure maxillectomy is often performed. For larger tumors, access through the nasal crease/upper lip may be necessary. Tumors involving the orbital floor or orbit often require orbital exenteration. Reconstruction is done with skin grafting and obturator placement. Larger defects are filled with free flaps.

Question 29

How are ethmoid sinus tumors managed surgically?

Answer 29

Ethmoid sinus tumors are surgically managed by either endoscopic sinus surgery for small tumors or craniofacial resection, requiring access both anteriorly through the sphenoethmoid area (through the nose) and superiorly
with a craniotomy (neurosurgery) to address the skull base/dura.

Question 30

When is orbital exenteration necessary in sinonasal/PNS tumors, and when is it not absolutely necessary?

Answer 30

It is necessary if extraocular muscles, optic nerve, bulb, or eyelid are involved. It is not necessary if there is only bone erosion or periorbital fat involvement.

Question 31

What are some indications for definitive radiotherapy in the management of sinonasal/PNS tumors?

Answer 31

Inoperable tumors (medically and technically).

Question 32

What are the indications for adj radiotherapy after resection of sinonasal/PNS tumors?

Answer 32

Maxillary sinus T3–T4 lesions or T1–2 adenoid cystic above Ohngren line, ethmoid sinus T2–T4 lesions (can consider omission of adj RT in T1 ethmoid per NCCN 2018), N+, + or close margins, +PNI, +LVSI, high-grade
histology.

Question 33

How is radiotherapy delivered and to what dose?

Answer 33

IMRT, volumetric modulated arc therapy, IGRT, proton beam therapy approaches, to 70 Gy (definitively) or 60–66 Gy (adj), to the tumor bed and margins; 50–56 Gy to low-risk areas. Use image fusion (MRI/PET) for planning purposes.

Question 34

Per the NCCN (2018), what altered RT fractionation regimens can be employed for maxillary sinus tumors when definitive RT is delivered without chemo?

Answer 34

Per NCCN 2018:
Accelerated (6 fx/wk during wks 2–6): 66–70 Gy for gross Dz and >50 Gy for subclinical Dz
Concomitant boost (bid last 2 wks): 72 Gy over 6 wks (1.8 Gy/fx large field and 1.5 Gy/fx same-day boost over last 2 wks)
Hyperfractionated: 1.2 Gy/fx bid to 81.6 Gy over 7 wks

Question 35

Is concurrent chemo a standard approach in the definitive management of sinonasal/PNS tumors with RT?

Answer 35

No. Prospective trials are evaluating CRT, and it can certainly be considered based on principles for other H&N cancers for which concurrent chemo is recommended (stages 3–4 treated definitively, or +margins or nodes with ECE in the adj setting).

Question 36

For which tumors should elective neck management be considered (with Sg or RT)?

Answer 36

Elective neck management should be strongly considered for tumors with squamous or undifferentiated histology and for T3 or T4 tumors of other histologies. It is controversial for ENB, though recommended by many centers. It may be left out for other subsites with N0 Dz.

Question 37

What studies/data support the use of ENI for maxillary sinus tumors?

Answer 37

Stanford data (Le QT et al., IJROBP 2000): 97 pts (36 RT alone, 61 Sg + RT), 12% nodal failure overall in levels I–II; 5-yr nodal failure risk 20% –ENI, 0% +ENI; 5-yr distant relapse rate 29% with neck control, 81% if neck failure.

MDACC data (Bristol I et al., IJROBP 2007): SCC/undifferentiated histologies nodal failure 36% in 36 pts without ENI vs. 7% in 45 pts with ENI.

Question 38

What have recent studies demonstrated regarding the use of adj IMRT for sinonasal/PNS tumors?

Answer 38

There was no significant improvement in terms of LC or OS; however, there was a lower incidence of complications with IMRT. (Madani I et al., IJROBP 2009; Dirix P et al., IJROBP 2010)

Question 39

What did the 2017 NCDB analysis (Robin TP et al., Cancer 2017) show regarding the multimodality management of sinonasal/PNS tumors?

Answer 39

Sup OS with multimodality therapies vs. Sg alone; adj RT (HR 0.658, p < 0.001), adj CRT (HR 0.696, p = 0.002), or neoadj therapy (HR 0.656, p =0.007); neoadj CRT associated with greater likelihood of achieving –margins
(OR 2.641, p = 0.045).

Question 40

Describe the recommended f/u schedule for pts treated for PNS tumors.

Answer 40

PNS tumor f/u (per NCCN 2018): H&P (q1–3 mos for yr 1, q2–6 mos for yr 2, q4–8 mos for yrs 3–5, and q12 mos thereafter), imaging as clinically indicated (consider baseline imaging post Tx), TSH q6–12 mos if neck RT.