Sinonasal Tract Tumors

Updated by Vinita Takiar and Gopal K. Bajaj

BACKGROUND

What is the incidence of sinonasal tract (SNT) tumors in the U.S.?

~2,000 cases/yr of SNT tumors (<1% of all tumors)

Is there a sex predilection for SNT tumors?

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

SNT tumors are more common in what continents?

SNT tumors are more prevalent in Asia and Africa.

What histologies are typically seen with SNT tumors?

Squamous (70%), adenocarcinoma, adenoid cystic, melanoma, esthesioneuroblastoma (ENB), sinonasal undifferentiated (SNUC), small cell, sarcoma (rhabdomyosarcoma), lymphoma, plasmacytoma, and mets

What nonmalignant entities present as a mass in the paranasal sinuses (PNS) or the nasal cavity?

Sinonasal polyposis, choanal polyps, and juvenile angiofibromas

What sinuses make up the PNS?

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

What structures border the maxillary sinus?

Anterior: facial bone

Anterolateral: zygomatic arch

Posterolateral: infratemporal fossa

Posterior: pterygopalatine fossa

Superior: orbital floor

Inferior: hard palate

Medial: nasal cavity

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

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

What is the local invasion pattern of ethmoid tumors?

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

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

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

What is the most common site for ENB?

The nasal cavity is the most common site for ENB.

What environmental exposures are associated with the development of SNT tumors?

Industrial fumes, wood dust, nickel, chromium, hydrocarbons, nitrogen mustard

WORKUP/STAGING

What are some presenting Sx of SNT tumors?

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

What is the basic workup for SNT tumors?

SNT tumor workup: H&P, labs, CT/MRI head/neck, Bx, and CT chest, dental consult if required (per NCCN, 2013)

Describe the T staging of maxillary tumors per the latest AJCC (7^th edition, 2011) classification.

T1: confined to sinus, no bone erosion

T2: bone erosion without involvement of posterior wall of maxillary sinus or pterygoid plate

T3: invasion of posterior wall of max sinus, pterygoid fossa, floor/wall of orbit, ethmoid sinus

T4a: invasion of ant orbital structures, skin of cheek, pterygoid plate, infratemporal fossa, cribriform plate, sphenoid or frontal sinus

T4b: invasion of orbital apex, nasopharynx, clivus, intracranial extension, CN involvement (except V2), dura, brain

How are the nodes staged for SNT tumors?

N1: single, ipsi, ≤3 cm

N2a: single, ipsi, >3 and ≤6 cm

N2b: multiple, ipsi, ≤6 cm

N2c: bilat or contralat ≤6 cm

N3: >6 cm

How are the overall SNT stage groups broken down (based on TNM)?

Stage I: T1N0

Stage II: T2N0

Stage III: T3N0 or T1–3N1

Stage IVA: T4aN0–2 or T1–3N2

Stage IVB: T4b or N3

Stage IVC: M1

What is the T stage for a maxillary tumor with involvement of the pterygoid plate vs. the pterygoid fossa?

Pterygoid plate involvement: T4a

Pterygoid fossa involvement: T3

What is the Ohngren line, and why is it important?

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 (due to invasion of the orbit, ethmoids, and pterygopalatine fossa). The relationship of a tumor to Ohngren’s line was an important prognostic factor, but with CT, MRI, and PET for imaging tumors, the significance of this line is principally historic.

For SNT tumors, what factors predict for nodal mets?

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 disease is very uncommon with adenoid cystic and adenocarcinomas.

What neck node groups are generally involved with SNT tumors?

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

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

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

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

The 5-yr OS rate for all stages of SNT tumors is ~45%

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

The 5-yr OS rate for N+ maxillary sinus tumors is <10%.

What is the 5-yr OS rate for nasal cavity tumors (all stages)?

The 5-yr OS rate for all stages of nasal cavity tumors is ~60%.

What is the overall LC rate for SNT tumors?

The overall LC rate is 50%–60%.

TREATMENT/PROGNOSIS

How are SNT tumors typically managed?

Surgical resection and adj RT +/- chemo. Consider induction chemo in SNUCs or in very advanced primary squamous carcinomas.

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

Partial (2 walls of maxilla removed) or total maxillectomy to – margins. For smaller tumors, endoscopic sinus surgery (ESS), 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 inferior, 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.

How are ethmoid sinus tumors managed surgically?

Ethmoid sinus tumors are surgically managed by either ESS 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.

When is orbital exenteration necessary in SNT tumors, and when is it not absolutely necessary?

It is necessary if periorbital fat or extraocular muscles are involved. It is not necessary if there is only bone erosion.

What are some indications for definitive radiotherapy in the management of SNT tumors?

Inoperable tumors (medically and technically)

What are the indications for adj radiotherapy after resection of SNT tumors?

Maxillary sinus T3–T4 lesions, ethmoid sinus T1–T4 lesions (per NCCN 2013), N+, + or close margins, +PNI, high-grade histology

How is radiotherapy delivered and to what dose?

IMRT, FSR, or SRS 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/CT) for planning purposes.

Per the NCCN, what altered RT fractionation regimens can be employed for maxillary sinus tumors when definitive radiation is delivered without chemotherapy?

Per NCCN (2013):

Accelerated (6 fx/wk during wks 2–6): 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

Is concurrent chemo a standard approach in the definitive management of SNT tumors with RT?

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

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

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.

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

Stanford data (Le QT et al., IJROBP 2000): 97 pts (36 RT alone, 61 surgery + 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: nodal failure 36% in 36 patients without ENI vs 7% in 45 patients with ENI

What have recent studies demonstrated regarding the use of adj IMRT for SNT tumors?

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)

TOXICITY

What is the RT dose tolerance of the retina?

The maximum RT dose tolerance of the retina is 45–50 Gy.

What is the RT dose tolerance of the optic chiasm?

The maximum RT dose tolerance of the chiasm is 50–54 Gy.

What is the RT dose tolerance of the parotids?

The RT dose constraints for the parotids are as follows: mean dose <26 Gy or V30 Gy <50%.

What is the RT dose tolerance of the lacrimal gland?

The RT dose tolerance of the lacrimal gland is mean dose <26–30 Gy, similar to that of other glands (e.g., the parotids).

Describe the recommended follow-up schedule for pts treated for SNT tumors.

SNT tumor follow-up (per NCCN 2013): H&P (q1–3mos for yr 1, q2–4mos for yr 2, q4–6mos for yrs 4–6, and q6–12mos thereafter), baseline CT/MRI after Tx and regular chest imaging if indicated clinically, TSH every 6–12 mos if neck RT

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