1. Marka Crittenden M.D. Ph.D.
Salivary Gland Tumors
Marka Crittenden M.D. Ph.D.

2. Anatomy Major Glands Minor Glands
Parotid, submandibular and sublingual glands
Minor Glands
Hundreds residing in the oral cavity, pharynx and paranasal sinuses.

3. Major Salivary Glands ? ? ?

4. Parotid Gland
Borders
Superior – zygomatic arch.
Posterior – angle of mandible under earlobe toward the mastoid tip.
Inferior – extends to the inferior aspect of the angle of mandible toward hyoid bone.
Medial – borders of the parapharyngeal-base of skull.
Lateral – below the skin of the preauricular cheek-upper neck.
Anterior – wraps around ascending ramus of mandible
Facial nerve divides the gland into the superficial (80 %) and deep lobe (20%)
Parotid duct (Stensons) is 5 cm long and opens opposite the second molar.
Lymphatic drainage – periparotid/intraparotid – lvl I – lvl II- lvl III.
Accessory parotid lobe – Present in 20% of patients.

6. Submandibular Gland Borders
Lateral – proximal half of the mandible.
Posterior – anterior to but near the low anterior margin of the parotid gland.
Inferior – approaches the level of the hyoid bone.
Majority of gland lies over the external surface of the mylohyoid muscle.
Lateral to and abuts the lingual and hypoglossal nerve and is medial to the marginal mandibular and cervical branch of the facial nerve.
Drains through Wharton’s duct in anterior floor of the mouth
Lymphatic Drainage Lvl I – Lvl II- Lvl III

7. Sublingual Gland 10% size of parotid gland
Located anterior floor of the mouth
Borders
Lateral –medial aspect of mandible
Inferior –mylohyoid muscle
Lingual nerve courses adjacent to sublingual gland
Drain into the floor of the mouth through Rivinus ducts
Lymphatic drainage – Lvl I- Lvl II- Lvl III

9. Epidemiology Salivary tumors 7% of head and neck tumors
Parotid tumors 10x more common then submandibular and 100x more common then lingual
Parotid 80% benign (pleomorphic adenoma)
Submandibular 50% malignant
Sublingual majority (65-88%) are malignant
Equal incidence between sexes
Risk Factors: nutritional deficiency, exposure to ionizing radiation, UV exposure, genetic predisposition, EBV

10. Pathology Benign Tumors Malignant tumors Pleomorphic Adenomas
Parotid – mucopidermoid most common – low grade, slow growing cured by surgery alone
Submandibular and minor salivary – adenoid cystic most common.

12. Adenoid Cystic Cribiform pattern – differentiated
Cribiform/solid pattern – moderately differentiated
Solid Features – undifferentiated
Natural history ranges from months to greater then 20 years.
Lymph Node spread <5%

13. Adenoid Cystic
Perineural spread common and can track along the cranial nerves back to the base of skull
40% develop pulmonary mets but survival of years can occur with pulmonary mets so primary must be managed

15. Metastatic Disease involving Parotid
Mechanism
Lymphatic spread – most common from skin
Hematogenous spread - lung
Direct extension – skin or osseous sarcomas

16. Staging T1 ≤ 2cm and no extraparenchymal extension
T2 > 2cm but not >4cm without extraparenchymal extension
T3 >4cm and or extraparenchymal extension
T4a invades skin, mandible, ear canal and/or facial nerve
T4b invades skull base and or pterygoid plates and or encases carotid artery

17. Parotid Tumors Clinical presentation Evaluation Asymptomatic mass
Cranial nerve palsey – inability to move one side of face, one shoulder, one side of tongue.
Evaluation
Trismus – to evaluate pterygoid involvement
CT/MRI
FNA in parotid tumors 90% sensitive and >95% specific
Never perform incisional or excisional biopsy

18. Parotid Tumors Lymph Nodes Distant Spread Rare in adenoid cystic
12% positive in clinically negative tumors.
Size and grade are risk factors
>4 cm 20% occult mets vs 4% in smaller tumor
High grade 49% risk regardless of histologic type vs 7% for low or intermediate
Distant Spread
Lung
25-35% risk for mucoepidermoid, adenoid cystic and malignant mixed tumors.
Routine CXR

19. Postoperative Radiation versus Surgery for Salivary Gland Tumors: Results from the literature
Series
# PTs
FUP length (y)
Prognastic factors
LC 5y
S S/R
Surv 5y
S S/R
MSKCC 92
S 10.5
S/R 5.8
Stage I/II
Stage III/IV
Positive nodes
High-Grade JH 87
All patients
MDACC
155
7.5
PMH
271 10 -
(RFS)

20. Submandibular tumor Clinical presentation Evaluation Asymptomatic mass
Painful mass as enlarges
Cranial nerve palsey –decrease sensation in ipsilateral lower teeth, lip and gums, inability to move ipsilateral oral tongue or inbality to move part of face.
Evaluation
CT/MRI – help to distinguish a pseudomass
FNA in submandibular tumors useful only if reveals a malignancy.
All lesions approached with a submandibular triangle dissection
Almost never perform incisional or excisional biopsy.

21. Submandibular Tumors Lymph Nodes Distant Spread
28% risk in submandibular tumors
Lvl I, II and III most common sites
Distant Spread
Lung >bone and liver

22. Sublingual Tumors Clinical presentation Evaluation
Asymptomatic swelling in floor of mouth
Cranial nerve palsey – ipsilateral loss of sensation of one side of tongue.
Evaluation
CT/MRI
Most tumors are malignant so FNA only useful if maligant
Always resect with a formal cancer surgery

23. Sublingual Tumors Lymph Nodes Distant Spread
Higher risk of LN spread then parotid tumors
Lvl I is first site of drainage
Distant Spread
Lung > bones and liver

24. Treatment Surgery -Parotid
90% confined to superficial lobe – perform superficial parotidectomy
If adjacent to deep lobe - total parotidectomy
If invades adjacent soft tissue – radical parotidectomy
Never perform piecemeal excision in an attempt to preserve facial nerve
Nerve grafting can be performed and RT can start3-4 wk post op without adverse affects
Frey’s syndrome – (gustatory sweating) due to redirection of parasympathetic and sympathetic nerve fibers to the dermal sweat glands

25. Treatment Surgery - Submandibular Surgery – Sublingual
Small tumor – gland excision
ECE –En bloc resection with extended supraomohyoid neck dissection
Surgery – Sublingual
Small and localized can resect without submandibular gland
Generally requires resection of submandibular gland as well.

26. Treatment Radiation – Surgically unresectable tumors
EBRT with photon and or electrons with conventional or altered fractionation
Brachytherapy ± EBRT
Neutron therapy

27. Treatment Radiation – Surgically unresectable tumors EBRT
Equivalent control rates as for equivalent head and neck squamous cell cancers
Early stage % control rates
Late and Recurrent 50-70%
Hyperfractionation
Wang and Goodman reported on 14 patients using 1.6 Gy bid to Gy.
5 yr LCR 82%

28. Treatment Radiation – Surgically unresectable tumors Brachytherapy
Used frequently with recurrent or advanced disease
5 yr LCR 60%
Neutron therapy
Biologic effect of neutrons less effected by hypoxia
Lethal effects less dependent on cell cycle
Repair of sublethal damage in malignant cells is less
RBE > 2.6
Severe late effect greater 17% versus 7%
Improved local control but no diff in overall survival

29. Treatment Postoperative Radiation Indications
Close surgical margins (deep lobe parotid tumors, facial nerve sparing)
Microscopically positive margin
High grade including adenoid cystic
Involvement of skin, bone, nerve (gross or extensive perineural invasion), tumor extension beyond capsule with periglandular and soft tissue invasion
LN spread
Large tumors requiring radical resection
Tumor spillage
Recurrence

30. Treatment Postoperative Radiation Technique
LCR with surgery and post op RT
T1 100% T2 83% T3 80% T4 43%
Technique
Parotid
Electrons – lateral en face
Mixed beam – 50-80% electron weighting lateral en face or wedge pair.
Photons - wedge pair or IMRT

31. Treatment Technique Portal margins – Parotid
Superior – top of zygomatic bone
Inferior – hyoid bone – thyroid notch
Anterior - 2cm ant to upper second molar
Posterior – posterior to mastoid tip.
Lateral - 2 cm flash on cheek
Medial – 2 cm medial from ipsilateral oropharyngeal area.
Electron portal margins are 1 cm greater
Usually 12 MeV- 16 MeV energy used

33. Treatment Technique Portal margins – Submandibular
Superior – 1cm above upper border of tongue
Inferior – Hyoid bone-thyroid notch interspace
Anterior – anterior aspect of mental symphysis
Posterior – BOT- jugulodigastric nodal area
Lateral – 2 cm flash of ipsilateral mandible
Medial – midline of tongue

34. Treatment Technique Portal margins – Sublingual
Superior – 1cm above upper border of tongue
Inferior – Hyoid bone-thyroid notch interspace
Anterior – anterior aspect of mental symphysis
Posterior – posterior aspect of the ascending mandibular ramus
Lateral – 2 cm flash of ipsilateral mandible
Medial – 2cm past midline

35. Treatment Dosage – Primary treatment
Accelerated fractionation with a delayed concomitant boost
Phase I 1.8Gy daily to 36 Gy
Phase II 1.8 Gy as in phase I in AM x 10 fractions to 54Gy and > 6hrs 1.6 Gy to GTVx 10 fractions to 16 Gy
Spinal cord dose < 45 Gy.
IMRT to 70 Gy for GTV 63 Gy CTV 1 and 56 Gy CTV2

36. Treatment Dosage – Post op treatment
Administered within 6 weeks of surgery
High Risk 2.0 Gy/fx to 60Gy and 1.8Gy/fx to 63Gy.
Small volume known microscopic disease 66 Gy.
Elective at risk 50 Gy (2.0Gy/fx) 54 Gy(1.8Gy/fx)
Gross residual 70Gy.

37. Side effects Salivary fxn Trismus
80% of saliva produced by major salivary glands
Loss of salivary fxn complete >35 Gy
Dose limit to spare salivary function is 26 Gy.
Trismus
TMJ and masseter muscle < 50Gy. PT during and after treatment

38. Adenoid Cystic Carcinoma
Post op RT always recommended
Post op RT of entire pathway of adjacent cranial nerve to base of skull always recommended
Regional LN spread is 15% and elective nodal irradiation is not standard
Surgery alone LCR 25-40% +RT 75%-80%

39. Pleomorphic Adenoma
Benign tumor – 75% of all parotid epithelial tumors.
Surgery is treament of choice
Multiply recurrent tumors can be treated with RT
>3 local recurrences
Large lesion with surgically inadequite margin
Microscopically positive surgical margins
Macroscopic residual disease
Malignant transformation
50-60 Gy dose

40. Minor Salivary Tumors
Highest concentrations of the glands in the oral cavity, palate, nasal cavity and paranasal sinus
Glands
No glands located in the gingiva or anterior half of the hard palate
50% malignant
Adenoid cystic is most common malignant histology seen.

41. Quiz What is the most common tumor of minor salivary glands
A. Pleiomorphic Adenoma
B. Adenoid cystic carcinoma
C. Mucoepidermoid carcinoma
D. Squamous cell carcinoma

42. Quiz What are the borders of the parotid gland?
Superior
Inferior
Anterior
Posterior
Zyogomatic arch
Hyoid bone
Ascending ramus of mandible
Mastoid process

43. Quiz The most common parotid tumor is A. Pleomorphic adenoma
B. Mucoepidermoid carcinoma
C. Adenoid cystic carcinoma
D. Detroit tigers

44. Quiz Most parotid tumors are ___________ A. Benign 60% B. Benign 80%
C. Malignant 60%
D. Malignant 80%

45. Quiz
All of the following are true regarding adenoid cystic carcinoma except?
A. It rarely spreads to Lymph nodes
B. It is a common minor salivary tumor
C. It typically does not involve nerves
D. 40% develop pulmonary metastasis

46. Quiz
Adenoid cystic of parotid s/p parotidectomy with perineural invasion, what is treatment field?
A. Post op bed
B. Post op bed and BOS
C. Post op bed and BOS and ipsilateral neck
D. Post op bed and BOS and bilat neck

47. Quiz
What is treatment of choice for cystic pleomorphic adenoma? After rupture or residual?
Superficial parotidectomy. If intraop cystic rupture, add post op RT

48. Quiz How are parotid tumors staged?
≤ 2cm
2-4 cm
Extraparenchymal, No VII involvement ± 4-6cm
>6cm, BOS, CN VII

49. Quiz
All of the following are indication for RT in pleiomorphic adenoma except?
A. Deep lobe involvement
B. Large >5cm
C. Recurrent tumor
D. Positive margin

50. Quiz What seperates the superficial parotid from the deep lobe?
Facial Nerve

51. Quiz
Intraparotid lymph node and a single 3cm neck node what is the most likely primary?
Skin
Parotid

52. Quiz True/False series. Indication for post-op RT for parotid tumors
Close but clear margin on benign pleomorphic adenoma < 3cm
Adenoid cystic with clear margin
High grade mucopidermoid
CN VII sacrifice for tumor close to nerve but not invading nerve