ANATOMY
Upper and
Lower Gingiva
Hard Palate
Lip
Oral Tongue
Ant 2/3
Buccal Mucosa
Floor Of mouth
Retromolar Trigone or
(Retromolar Gingiva
Buccal Mucosa
Anatomy
Notes

Retromolar trigone??:- Apex in line
with maxillary tuberosity (behind last
molar teeth), the lateral border extend
with buccal mucosa, medially it blends
with anterior tonsillar pillar, base is
formed by the last lower molar and
the adjacent gingivolingual sulcus.
Other Trigones
Trigone of bladder: a triangular region
of the wall of the urinary bladder, the
three angles corresponding with the
orifices of the ureters and urethra; it is
an area in which the muscle fibers are
closely adherent to the mucosa.

Carotid trigone: the triangular area
bounded by the posterior belly of the
digastric muscle, the sternocleidomastoid
muscle, and the anterior midline of the
neck.

Olfactory trigone: The triangular area
of gray matter between the roots of the
olfactory tract.
Oral Tongue
Intrinsic Muscles (speech)
• Longitudinal, vertical and transverse
Extrinsic Muscles (move body)
• Genio, hyo, stylo glossus
Four taste qualities, a novel taste, that
is referred by the Japanese word umami
which means delicious, ‘‘fifth taste’’.
 Umami taste is found in a diversity of
foods (e.g. fish, meat, milk, tomato
and some vegetables) and is elicited
by monosodium glutamate and certain
ribonucleotides.



Aging, pregnancy and menopause.
Poor dentition and hygiene, alcoholism
and/or excessive smoking are common
conditions that affect taste.
Patients with xerostomia, Sjogren
syndrome, vitamin and zinc deficiency
liver and kidney disorders, endocrine
disorders,
diabetes
mellitus,
psychological disorders,
Floor of Mouth


A semilunar space extending from the
lower
alveolar
ridge
to
the
undersurface of the tongue.
The floor of the mouth overlies the
mylohyoid and hyoglossus muscles.
Tongue Nerve Supply



Lingual (Meneeein).
Chorada Tympani.
Hypoglossal Nerve.
Staging

As other Head and Neck but not
Nasopharynx.
T4a and T4b


Usually T4b tumor control probability
is very low.
Resectability is impossible.
 Examination
Under
Anesthesia can be done
with the surgeon to assess
the disease similar to that
of the Cervix.
Start by Support




Nutritional support.
Dental Support.
Psychological Support.
Speech and Swallowing Consult.
Node Story

The 5-year cancer-specific survival can
be as high as 70% to 90% for patients
without lymph node metastasis but
drops by half for patients with nodepositive disease.
Staging and Node in Head
and Neck Cancer


N2 disease put patient Stage IVA.
N3 disease put patient Stage IVB.
Nodes
N0

should be treated prophylactically Level I to
III.
Treatment
ORAL CAVITY BASICS

-
-
ASK YOUR SELF THREE QUESTION?
Is it small (T1 or T2 ) or large (T3 or
T4)?.
Is the lesion Central or Lateralized?.
Is the Nodes negative or Positive?.
Rules


The closer to the midline the primary, the
greater the risk of bilateral cervical nodal
spread.
The mucosa of the upper and lower
alveolus and hard palate is fixed to the
underlying periosteum so invasion of the
adjacent bone occurs relatively early
making these tumors less suitable for
primary radiotherapy
Early Lesion


Surgical resection: where rim rather segmental
resection should be performed. Situations
where removal of the bone is required to
achieve clear margin.
Re-resection should be performed to achieve
clear histological margins if the initial resection
has positive margins.
Lymphatics
first echelon
upper gingiva
lower gingiva
hard palate
retromolar trigone
submandibular and subdigastric
nodes
submandibular and subdigastric
nodes
submandibular and subdigastric
nodes
incidence of clinical nodal positivity
at presentation
subdigastric
nodes
Second echelon
anterior
cervical nodes
according to anatomic subsite:
- 20 – 30% for gingival and retromolar trigone tumors (with slightly higher
risk of nodal disease for lower gingival vs upper gingival tumors) and 10%
for hard palate tumors
- incidence of clinically positive bilateral nodes rare
incidence of occult nodal disease overall: 20%
Planned Neck dissection


What does it mean?
Controversy continue.
Lip Cancer


In Early stage T1 and T2 surgery
results equal to RT.
So How to choose?
LIP

Surgery may be preferred in :
- T1 lesion with good functional and
cosmetic outcome.
- Young patient with outdoor sunlight
exposure.
- Diffuse superficial lesion of the
vermillion, or presence of severe
actinic
keratosis
adjacent
to
carcinoma.
N0 disease



In the N0 neck, occult metastases are
estimated to occur in 5% to 10% of cases.
Therefore, elective neck dissection is not
routinely performed in the N0 neck.
Neck dissections are generally performed
when cervical metastases are clinically or
radiographically apparent.
Primary Radiotherapy




Target Volume:
Tumor with a margin
Tumor with a margin+first echlon
lymph nodes.
Tumor with a margin + whole neck .
WHEN?
LIP
What is the likely diagnosis?
How would you treat this patient (describe your technique in detail)
Oral Tongue
Tumor Thickness in Oral
Tongue

Po
demonstrated
that
tumor
thickness in oral tongue carcinomas
was the only significant factor that had
significant
predictive
value
for
subclinical nodal metastasis, local
recurrence, and survival in multivariate
analysis.


External beam alone may not be very
successful.
Boost using brachytherapy is
recommended.
Oral Tongue


Before external-beam RT, the cancer
is photographed and diagrammed to
document its extent at the time of the
implant.
Sometimes, the anterior and posterior
borders of the lesion are tattooed with
two tiny (1–2 mm) marks.

If teeth with metal fillings lie against
the tongue or buccal mucosa, a thin
layer of gauze (a few millimeters thick)
is inserted between the teeth and
tongue or buccal mucosa to prevent a
high-dose
effect
secondary
to
scattered low-energy electrons.
Tongue depressor may be
different
Spot the difference?
Advanced Stage



Patients with resectable disease who are fit
for surgery should have surgical resection
with reconstruction.
Patients with node positive should be
treated
with
modified radical neck
dissection.
Elective dissection of the contralateral neck
should bee considered if the primary tumor
is locally advanced arises form the midline
or there are multiple ipsilateral nodal
involvement.
Advanced Stage Ctn
When Concurrent CRT
Only




Tumor can not be resected.
General condition is inadequate.
Patient doesn’t wish to go for surgery.
Nodal level I to IV should be
irradiated.
Nodal Disease


Patients with N1 disease should be
treated by chemoradiotherapy to the
primary and node.
Patient with N2 or N3 disease should
be treated by
chemoradiotherapy
followed by planned neck dissection.
When Chemotherapy is
not Suitable


Cetuximab with radiotherapy should
be considered.
Where radiotherapy to be used
without chemotherapy or cetuximab,
A modified fractionation schedule should
be considered.
Management

Gingival and hard palate cancer
– Early (T1 – 2) tumors
– Surgery is recommended over radical
irradiation due to the high incidence
of bone involvement – irradiation
risks bone exposure after treatment
of the tumor
– Very superficial tumors may be
treated with radical irradiation
– Adjuvant irradiation is added for
adverse primary (i.e., high-grade
mucoepidermoid or adenoid cystic
pathology) or neck pathology
– Advanced (T3 – 4) tumors
– Surgery and adjuvant irradiation is
recommended
– Unresectable disease may be treated
with adjuvant irradiation followed by
attempted resection or
hyperfractionated irradiation alone

Retromolar trigone cancer
– early (T1 – 2) tumors:
radical
irradiation
is
recommended
over
surgery due to more
favorable morbidity profile
– advanced (T3 – 4) tumors
– surgery
and
adjuvant
irradiation is recommended
– unresectable disease may
be
treated
with
neoadjuvant
irradiation
followed by attempted
resection
or
hyperfractionated
irradiation alone

Results
gingival cancer
– M. D. Anderson (see Leibel, p. 475) treated 48 patients with radical irradiation
– survival: 5YOS of 46%
– patterns of failure: local control of
– 70% for T1 – 2,
– 59% for T3,
– 29% for T4

hard palate cancer
– Memorial (Evans. Am J Surg 142:451. 1981) treated 49 patients with surgery with or
without adjuvant irradiation
– survival



surgery alone: 5YDFS of 75% for stage I, 46% for stage II, 40% for stage III, and 8% for stage
IV disease
surgery and adjuvant irradiation 5YDFS of 25% for stage IV disease
retromolar trigone cancer
– M. D. Anderson (Lo. IJROBP 13:969. 1987) treated 159 patients with retromolar trigone
and anterior tonsillar pillar tumors with radical irradiation with surgery reserved for
salvage
– survival: 5YCSS of 83%
– patterns of failure: local control
– after irradiation: 70% for T1 – 2, 76% for T3, and 60% for T4
– after surgical salvage: < 90% for all T stages
Standard ttt

T1-T2,N0 Any site (except retromolar
trigone)
– Surgery alone with staging neck sampling:
– Plus adjuvant radiotherapy for high risk
situation


Microscopic margins <5mm (irrespective of intraoperative revision or additional post-resection sampling
of the surgical site)
> 1 additional features at primary:
– Poorly differentiatied
– Peri-neural spread
– Angiolympatic invasion

Lymph node involvement at pathology:
– Extracapsular extension in positive lymph nodes
– Multiple lymph nodes
– >3 cm lymph nodes
Standard ttt.





T1-T2 N0 Retromolar trigone
Radiotherapy Alone with surgical Salvage 􀂾
60 Gy in 25 fractions ?
4-6 MV beam quality
Homolateral wedge pair (preferable) in lateralised
lesions: 􀂾
–
–
–
–
–
disease limited to 1 cm of palate involved 􀂾
disease limited to 1 cm of tongue involved 􀂾
Parallel opposed as necessary 􀂾
3 phases (including cord shield where appropriate) 􀂾
Augment posterior neck with electrons after cord Pb
where appropriate 􀂾
– Ant or Ant/Post ‘low’ neck parallel opposed (4-6 MV) or
hemisplits in unilateral techniques
Standard ttt.

AnyT, N+ or T3-T4, N0 (except retromolar trigone)
M0
– Surgery with neck dissection +/- adjuvant post-operative
radiotherapy:

Plus adjuvant radiotherapy for high risk situation
– Microscopic margins <5mm (irrespective of intra-operative revision or
additional post-resection sampling of the surgical site)
– > 1 additional features at primary:
 Poorly differentiatied
 Peri-neural spread
 Angiolympatic invasion
– Lymph node involvement at pathology:
 Extracapsular extension in positive lymph nodes
 Multiple lymph nodes
 >3 cm lymph nodes
– Surgically ‘unstaged’ neck:
 No surgery to a neck
Standard ttt.
POST-OPERATIVE XRT
 60 Gy in 30 fractions for original site of
gross disease where feasible using reducing
field techniques
 66 Gy in 33 fractions to sites of positive
margins
 50 Gy to other potentially involved nodal
sites
 Parallel opposed (4-6 MV) or ipsilateral
wedge pair for lateralized lesions
RADIOTHERAPY ALONE

Retromolar Trigone (AnyT, Any N)
Primary radiotherapy indicated all cases. Exception is
gross bulk disease extending through bone and/or skin
involvement where surgery should be considered followed
by adjuvant radiotherapy.

All Oral cavity T3-T4 or Any N +
– Where surgical morbidity at primary site anticipated
and considered not appropriate
– where patient declines surgery
– or neck disease is unresectable and primary not yet
treated surgically
– Unresectable neck and primary already resected:

assess risk to the primary and consider inclusion in plan for
neck to administer 70 Gy in 35 fractions with Cisplatin
Doses & Beam
arrangement

Dose fractionation schedules +/chemotherapy
– 70 Gy in 35f with Cis-Platin (Intergroup usually) or
– 60 Gy in 25f (reserve for frail or ‘patient preference’
declining ‘standard’ treatment)

Beam arrangement (technique)
– Parallel opposed or angled down wedge pair as necessary
with (4-6 MV)
– Ant or Ant/Post ‘low’ neck if parallel pair
– Augment posterior neck with electrons after cord Pb
Targets for non-surgical treatments
(any T, any N, M0) -PMH

Primary and gross neck node(s):
– Phase 1 : 1.5 cm CTV margin (superior:
mastoid to inferior: clavicle)
– Phase 2 : 1.5 cm CTV margin (cord
shield, including custom ‘Step back’ shape
for posterior mid-line disease)
– Phase 3 : 0.5 cm CTV margin on primary
or gross nodes
Lymph nodes management

Node inclusion:
– Zones 2 to 5 included to adjuvant dose (50 Gy in 25
fractions or equivalent) (Leuven/Rotterdam consensus)
– Retropharyngeal nodes if extensive other nodal
involvement

Dose fractionation:
– Gross nodes always receive full dose with minimum CTV
margins as used for the primary, unless planned surgery is
undertaken.
– Gross nodes undergoing planned surgery (see below)
should receive a minimal ‘microscopic’ dose, depending on
the overall dose-fractionation chosen, prior to planned
surgery.
– Uninvolved node regions within the risk zones should be
treated to a ‘microscopic’ dose depending on the overall
dose-fractionation chosen.
Radiotherapy technique

External Beam alone???
Organ Preservation

You still can Try CRT if organ preservation is
required. (provided salvage surgery may still
be an option. e.g. patient reliable for good
follow-up. Surgeon reliable for good
surgery.
Famous Laryngeal preservation trials:
-Veterans Affairs (larynx neoadjuvant), EORTC
(Hypopharynx neoadjuvant),
(RTOG 91-11 larynx Concurrent CRT value).
-Urba et al JCO 2006(NEW is the use of
concurrent CRT if good response to the
neoadjuvant treatment.
Patient Preparation
Dental.
 Nutritional.
 Psychological.
 Council.
 Immobilization.
 Simulation.

Immobilzation


Max. Extension still possible for easily
shielding of the oral cavity.
Tongue bite? What was the question?
Portal Arrangements

Opposed –lateral photon fields, with
the patient immobilized in supine
position are used for treatment of
most cancers :
oral cavity, Larynx, pharynx.
Superior border: Determined by the
location of the known disease and
likely spread pattern.
In General: Either it will be
1- At the base of skull when we want to
include the retropharyngeal node, e.g.
Hypopharynx.
 Superior
Nasopharynx
Hypopharynx
Oropharynx
Oral cavity:
Larynx
border:
Above skull base. because the primary at skull
base.
Skull base? Retropharyngeal nodesz
Skull base? Primary at skull base.
Do you want lymph node?
So skull base/If not take only a margin (1 to 2 cm).
Glottic? Above the glottis.
Supraglottic? Lymph nodes so skull base.
Subgltic (very rare) only margin above the
larynx.
Glottic with extensive supra? Skull base.


Eisbruch et al. established dose thresholds for the
parotid gland: mean dose ≤24 Gy and ≤ 26 Gy for
unstimulated and stimulated salivary flow,
respectively. Also, partial volume thresholds were
established:
67%, 45%, 24% of the parotid gland volume
receiving ≥ 15 Gy, ≥ 30 Gy, ≥ 45 Gy, respectively.
They observed that if the dose to the parotid glands
exceeds (one or more of) these thresholds, Parotid
salivary flow would significantly decrease
Oropharynx



Base of Tongue.
Tonsil and Faucial arche.
Soft Palate.