Paranasal Sinus and Nasal Cavity

Review Flashcards

Ohngren’s Line

• Extends from medial canthus to the mandibular angle

• Theoretical line used divide the maxillary antrum into anteroinferior and posterosuperior portion

• Postero/suprastructure - poor prognosis with early extension

Paranasal Sinus Borders

• Superior - orbital floor

• Medial - thin walls of the nasal fossa

• Posterior - pterygoid area (orbital apex and paranasopharyngeal area)

• Inferior - hard palate and superior alveolar ridge

Treatment management of the nasal vestibule is:

• Radiation therapy

• Surgery is limited to small lesions and optimal locations

Radiation therapy treatment to the nasal cavity is prescribed ______ Gy for radiation alone or a postoperative dose of _______Gy.

• 74-79 Gy

• 60-68 Gy

Risk factors for paranasal sinus cancer:

• Chromium, Asbestos, Nickel

• Glues, formeldahyde, etc

• Dusts from woods, textiles, leathers

• Viral

• HPV

Most common lymph nodes involved in paranasal and nasal treatment areas:

Submandibular and Jugulodigastric (Levels I-II)

Treatment modalities for paranasal cancer:

• Surgery

• Radiation

• Chemotherapy

Most common histology for cancer of the paranasal sinus:

Squamous cell carcinoma

Epidemiology of paranasal sinus:

• Age 50-60

• Higher incidence in Japan and South Africa

• More common in men than women

• very rare - <1% of all malignancies

Paranasal sinus signs and symptoms

• Frequent nosebleeds

• decreases sense of smell

• one-sided nasal obstruction

• pain above/below the eyes

• enlarged neck lymph nodes

T/F: Tumors of the paranasal sinus exhibit signs and symptoms at the initial onset of the disease.

False - symptoms arise when extension beyond the outside sinus walls occurs and is considered “silent” until then

What are the 4 paranasal sinuses?

• Frontal

• Sphenoid

• Ethmoid

• Maxillary

Approximately ____% of paranasal sinus cases present with nodal disease and _______% will develop nodal disease during the disease course.

• 10%

• 25-35%

What 3 anatomical parts comprise the nasal cavity?

• Vestibule (open airway)

• Septum (cartilage)

• Turbinates (Conchae)

What is the purpose of a bite block in paranasal and nasal cavity irradiation?

• Avoid bolus effect and moist desquamation at the commissure of the lips

• Displace tongue inferiorly from the treatment field