Site:
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Oropharynx (Base Of The Tongue, Tonsillar Fossa, Lateral Oropharyngeal Wall, And Faucial Arch)
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Stage:
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Stage I & II, T1 N0 M0, T2 N0 M0
Stage III & IV, T3, T4 N0, T3, T4 N1, & T3, T4N2, N3
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- DIAGNOSTIC EVALUATION
- EXAMINATION UNDER ANESTHESIA AND BIOPSY
- TREATMENT
- RECONSTRUCTION
- ADJUVANT TREATMENT
- FOLLOW UP
- BIBLIOGRAPHY
I. DIAGNOSTIC EVALUATION:
Clinical Evaluation:
- Complete history and physical examination
Recording the presence and duration of symptoms such as pain, soreness
of throat, otalgia, odynophagia, dysphagia, trismus, neck mass and
voice changes such as hoarseness, "hot potato voice", and slurred speech.
It should include history of risk factors such as the use of tobacco
and alcohol, the occurrence and extent of weight loss and of all other
medical conditions.
- Complete examination of the head and neck.
Includes examination of all the areas of the oral cavity, pharynx,
and indirect laryngoscopy. If indirect laryngoscopy is not adequate,
fiberoptic examination of the larynx and pharynx is necessary. Palpation
of the floor of the mouth, tongue, base of the tongue and or tonsil
to evaluate the "base" or depth of the tumor and its proximity to the
mandible. The examination includes an assessment of the status of the
mandible and the dentition, as well as an evaluation of the status
of the airway. Palpation of the neck bilaterally, recording the location
(Group or Level I - VI), size, mobility, and relationship of the node(s)
to adjacent structures. The staging of the primary and of the cervical
lymph nodes must be documented.
- Biopsy of primary
The biopsy can be performed in the office with local anesthesia
and a cup- biopsy forceps. If the patient has a severe gag reflex,
biopsy may be necessary under general anesthesia, in the operating
room. To do this, in patients with large tumors, a tracheostomy may
be necessary.
Fine needle aspiration biopsy of suspected metastatic disease may be
performed in selected cases. (Open surgical biopsy of suspected metastatic
disease is not indicated)
Imaging Studies:
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Panoramic x-ray (Panorex) of the mandible and/or dental X-rays.
When necessary to adequately assess the status of the patient's
dentition or mandibular invasion. In anticipation of radiation therapy
or the need for a mandibulotomy.
- CT scan / MRI of the primary and neck
To assess the extent of the primary, its relation to the mandible,
and to evaluate if there is any mandibular involvement.
In the absence of palpable adenopathy, they may be useful to
assess the status of the cervical lymph nodes in patients that
are obese or have a thick, muscular neck.
To assess the presence of parapharyngeal adenopathy
When a large node is palpable in the neck, may be useful to clarify
its relationship to the carotid artery, the paraspinal muscles
or the cervical spine.
Laboratory Tests:
- Pre-anesthesia laboratory tests (according to institutional guidelines)
- Baseline liver function tests (optional)
Consultations:
- Radiation therapy consult
In anticipation of possible need for post-operative radiation therapy
or to use radiation therapy as a definitive primary modality of treatment
when appropriate.
To assess the status of the teeth and to make recommendations regarding
the condition of the mandible prior to surgery, mandibulotomy or post-operative
radiation therapy. The evaluating dentist should be versed in the effects
of radiotherapy on dentition. This evaluation should be done with knowledge
of the treatment portals planned for the radiotherapy.
Optional:
- Radiation therapy consult
Either for free tissue transfer or for myocutaneous flap.
For pre-operative counseling regarding possible post-operative speech
and swallowing rehabilitation.
- Internal Medicine/ Cardiology/ Pulmonology/Anesthesiology
As needed to evaluate coexisting conditions that may preclude or
increase the risk of general anesthesia
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II. EXAMINATION UNDER ANESTHESIA AND
BIOPSY:
This is an important step in the evaluation of tumors of the oropharynx.
- Palpation of the base of the tongue and direct evaluation of the extent
of the disease, especially the lower extent of the disease in the pharyngeal
wall and to rule out involvement of the hypopharynx. The adequacy of the
airway should be judged at this time.
- Direct laryngoscopy, pharyngoscopy.
- Esophagoscopy (Optional, unless symptoms present)
- Bronchoscopy should be considered only if there are abnormal clinical
or radiographic findings.
- It is appropriate to have an intraoperative consultation with the radiotherapist,
especially if the patient is to be treated with radiation therapy as a
primary modality or planned interstitial implantation for tumors of the
base of the tongue is being considered.
- In patients with large tumors it may require tracheostomy under local
anesthesia.
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III. TREATMENT:
The decisions regarding the treatment of cancer of the oropharynx must be
individualized. Tonsillar cancers are more radiosensitive and general practice
is to treat them by radiation therapy with surgery as salvage, unless the
patient presents with very early tonsillar cancer. A bulky nodal disease
from tonsillar cancer also responds extremely well to radiation therapy.
On the other hand, tumors of the base of the tongue, if early, can be resected
or treated with radiation.
In advanced cancers of the base of the tongue, generally surgery is preferred
as the initial modality followed by radiation therapy; however, external
radiation therapy along with brachytherapy may be a good choice. In general
nodal metastases from base of tongue tumors do not respond as well to radiation
and will usually require neck dissection for persistent clinical disease.
Primary tumor:
Generally T1 or T2 primary tumor of the oropharynx can be treated equally
well with surgery or radiation therapy. The choice of treatment will depend
on the patient's preference, the patient's medical condition, the institutional
practice and the complexity of the surgical exposure. Treatment of base of
the tongue tumors may include brachytherapy. Adequate surgical approaches
and exposure of early tumors of the oropharynx may be difficult requiring
mandibulotomy, pharyngotomy or occasionally, if the tumor is adherent to
the mandible, composite resection with segmental mandibulectomy. Generally
T3 and T4 tumors are treated with surgery (if consistent with a reasonable
functional outcome and perioperative risk) and, in most instances, postoperative
radiation therapy. Otherwise they may be treated initially with radiation
therapy. Predominantly exophytic, poorly differentiated or lymphoepithelioma
type tumors may be treated initially with radiation therapy.
External radiation therapy, along with interstitial implantation (brachytherapy)
to the base of the tongue, may result in equally good local control and avoid
morbidity related to resection of the tumors of the base of the tongue. However,
neck dissection is usually necessary for persistent palpable disease.
Neck:
N0:Many base of tongue and lateral oropharyngeal wall tumors have a tendency
to cross the midline. Consequently, the incidence of metastases to both sides
of the neck is high in tumors of the oropharynx. Therefore, treatment should
consist of elective bilateral neck dissection or neck irradiation. If treated
with surgery, indications for postoperative irradiation are outlined below.
N1:Ipsilateral modified neck dissection where the spinal accessory nerve
is preserved, or if the disease is at Level I, ipsilateral supraomohyoid
neck dissection may be considered.
N2 or N3:Ipsilateral radical neck dissection with sacrifice of sternomastoid
muscle, internal jugular vein and spinal accessory nerve should be considered.
If the tumor is away from the spinal accessory nerve, every effort should
be made to preserve the spinal accessory nerve.
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IV.RECONSTRUCTION:
Primary closure may be possible if the lateral pharyngeal wall or a small
portion of the base of the tongue are resected. For larger defects a pectoralis
muscle myocutaneous flap or a free flap may be considered.
The surgical treatment also includes:
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Frozen section evaluation of margins as needed to ensure adequate resection.
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Dental extraction if indicated.
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Mandibulotomy for exposure and rigid fixation with wires or mini-plates.
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Insertion of suction drains.
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Tracheostomy.
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Orientation of the primary and neck specimens to the pathologist, with
appropriate identification of the groups/levels of lymph nodes removed).
Post-operative and Home Health care:
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Hospitalization for 7 - 21 days.
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Tube feedings.
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If the patient is unable to eat by the time of discharge,
patient may require tube feedings at home. If the tumor is extensive
and patient is likely to have considerable difficulty in swallowing,
consideration may be given to inserting a percutaneous gastrostomy (PEG).
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Removal of the drains when the output is < 30 - 50 cc's
per 24 hours.
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Intensive oral irrigation and oral care.
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Tracheostomy care and patient education for tracheostomy.
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Removal of neck sutures in 7 - 10 days
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If the patient has an adequate airway and can tolerate
oral feedings, consider weaning from tracheostomy. If there is considerable
edema and difficulty in swallowing, tracheostomy tube may be left in
place through the post-operative radiation therapy course.
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V.ADJUVANT TREATMENT:
Role of chemotherapy in Stage III & IV:
- Chemotherapy: The role of chemotherapy in the treatment of tumors of
the oropharynx remains under active investigation. Chemotherapy should
be used only under an approved experimental protocol.
- If patient has extensive tumor of the oropharynx which may necessitate
total laryngectomy, an IRB approved larynx preservation protocol may
be considered.
Post-operative radiation:
Indications:
Microscopically positive margins:
- Presence of extensive perineural or intravascular invasion.
- Multiple histologically positive nodes.
- Positive nodes at multiple levels in the neck.
- Presence of extracapsular extension of tumor.
Timing:
- Radiation is initiated within a reasonable period after healing has
occurred.
- Total dose and fractionation:
- These are determined by the clinical and pathological findings. The
usual range is 50 - 70 Gy in daily fractions of 1.8 to 2.0 Gy in 5 to
8 weeks. This may include a brachytherapy boost when indicated by pathological
findings such as unsatisfactory margins.
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VI.FOLLOW UP:
Follow-up appointments are scheduled on an individual basis
determined by the risk of recurrence, to survey for the development of second
primary tumors, to deal with morbidity from treatment (i.e. speech and swallowing
problems as well as wound care), to provide social and psychological support,
and to deal with comorbidity not directly related to the cancer itself.
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Periodic examinations by the head and neck surgeon may
be necessary during radiation therapy in patients experiencing difficulty
with nutritional intake, airway or pain control.
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Periodic examinations by the radiation oncologist and a
dentist in patients that received radiation therapy
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After all treatment is completed a general formula which
is modified according to the individual patient's characteristics is:
1st year post treatment : 1-3 months
2nd year post treatment : 2-4 months
3rd year post treatment : 3- 6 months
4th and 5th years : 4- 6 months
After 5 years : Every 12 months
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Chest radiographs, yearly.
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Liver enzymes, yearly.
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Thyroid function tests should be monitored within the first
year following completion of treatment if a thyroid lobectomy is performed
(along with laryngectomy) or if the patient received radiation to the
lower neck. These studies should be repeated according to clinical findings
on follow-up examinations.
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VII.BIBLIOGRAPHY:
O'Brien C, Castle G, Stevens G, et al. Limitations of radiotherapy
in definitive treatment of squamous carcinoma of the tonsillar fossa. Aust
NZJ Surg, 62: 709-713, 1992.
Harrison LB, Zelefsky MJ, Sessions RB, et al. Base of tongue
cancer treated with external beam irradiation plus brachytherapy: oncologic
and functional
outcome. Radiology 184: 267-270, 1992.
Wang C, Montgomery W and Efird J. Local control of oropharyngeal
carcinoma by irradiation alone. Laryngoscope, 105: 529-533, 1995.
Weber R, Gidley P, Morrison W, et al. Treatment selection
for carcinoma of the base of tongue. Am J Surg, 160: 415-419, 1990.
Million R, Parsons J and Mendenhall W. Selection of treatment
for squamous cell carcinoma of the oropharynx. Head Neck Cancer, Proc. 3rd,
Conf. 3:785-792,
1993.
Spiro RH, Gerold FP, Shah JP, Sessions RB, Strong EW. Mandibulotomy
approach to oropharyngeal tumors. Am J Surg, 150, Oct. 1985.
Harrison L, Zelefsky M, Armstrong J, et al. Performance status
after treatment for squamous cell cancer of the base of the tongue. Int J
Rad Onc Biol, Phys,
30: 953-957, 1994.
Pfister D, Harrison L, Strong E, et al. Organ-function preservation
in advanced oropharynx cancer: results with induction chemotherapy and radiation.
J of
Clin Onc, 13: 671-680, 1995.
Horiot JC, Le Fur R, N'Guyen T, et al. Hyper-fractionated
compared with conventional radio-therapy in oropharyngeal carcinoma: An EORTC
randomized trial. Eur
J Cancer, 26: 779-80, 1990.
Merlano M, Vitale V, Rosso R, et al. Treatment of advanced
squamous cell carcinoma of the head and neck with alternating chemotherapy
and radiotherapy.
N Engl J Med, 327: 1115-21, 1992.
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