Overview of Management

Lymph Node Biopsy

• The goal of lymphatic mapping and sentinel lymph node biopsy is to identify and remove the lymph node most likely to contain metastases in the least invasive fashion. * Sentinel node - the first node to receive drainage from the tumor site.

This node is the node most likely to contain metastases, if metastases to that regional lymph node basin are present.

• Recent studies evaluating treatment of an N0 neck have investigated the use of sentinel lymph node biopsy, which attempts to predict the disease status of the neck based on the first echelon of nodes that drain the tumor.

Metastatic Work-Up

• Vigilance for second primary tumors

• Patients diagnosed with a head and neck cancer are predisposed to the development of a second tumor within the aerodigestive tract

• Patients with a primary malignancy of the oral cavity or pharynx are most likely to develop a second lesion within the cervical esophagus

• Once cancer has been proven by biopsy, a CT scan of the chest will be ordered to rule out distant metastasis

• Contrast-enhanced CT and MRI of the head and neck may be performed for evaluation of the tumor and detection of occult lymphadenopathy

• CT scanning - best at evaluating bony destruction

• MRI - determine soft tissue involvement and is excellent at evaluating parotid and parapharyngeal space tumors

• Chest radiography or chest CT is performed to rule out synchronous lung lesions

• Serum tumor markers such as alkaline phosphatase and calcium may be determined, but such tests are not standard.

Positron Emission Tomography (PET) evaluates neck metastases with a sensitivity equal to that of CT

• able to detect a higher percentage of lung metastases than chest radiography, bronchoscopy, or CT

• but specificity ranges from 50% to 80%, and how to treat a patient with a positive PET and an otherwise negative lung workup is still in question

• most common sites of distant spread are the lungs and bones, whereas hepatic and brain metastases occur less frequently

• risk for distant metastases is more dependent on nodal staging than on primary tumor size

Staging

• Clinical staging of the neck is based primarily on palpation, although radiographic studies, including computed tomography (CT) and magnetic resonance imaging (MRI), have been shown to be accurate in detecting positive nodes

T1N2bMX

Imaging for ResectabilityPanoramic x-ray of the mandible• scanning dental X-ray of the upper and lower jaw• shows a two-dimensional view of a half-circle from ear to ear• shows a patient's nasal area, sinuses, jaw joints, teeth and

surrounding bone• can reveal cysts, tumors, bone irregularities• the mandible can also have an indentation on its lower border

when the patient's masseter has been clenching and grinding• shows the entire mandible, including all of its lower border

• Indications for cortical or rim resection of the mandible as determined by physical examination, CT scan, orthopantomogram, and dental films

a. Tumor close to but not involving the periosteum of mandible b. Tumor involving only mandibular periosteumc. Tumor adjacent to cortical bone of mandible with no evidence

of invasion beyond superficial cortexd. Tumor adjacent to dentition with no evidence of involvement

of periodontal ligament

Indications for segmental resection of the mandible as determined by physical examination, CT scan, orthopantomogram, and dental films

a. Invasion of the medullary space of the mandible b. Tumor fixation to the occlusal surface of the mandible in the edentulous

patientc. Invasion of tumor into the mandible via the mandibular or mental foramend. Tumor fixed to the mandible following prior radiotherapy to the mandible,

particularly if the tumor is located on the occlusal surfacee. Tumor adjacent to carious dentition with involvement of the periodontal

ligamentf. Hypoplastic edentulous mandible with significant loss of vertical height

precluding safe performance of a rim resection

• Cortical or rim mandibulectomy – if (+) adherence to mandibular periosteum without bony erosion

• Segmental resection – if (+) mandible invasion

Resection of retromolar trigone tumors:

• usually requires a marginal or segmental mandibulectomy with a soft-tissue and/or osseous reconstruction in order to maximize a patient's postoperative ability for functional speech and swallowing

• Ipsilateral elective and therapeutic neck dissection is performed because of the risk of metastasis to the regional lymphatics

Results of the Patient

• Head & neck examinations: Chest X-ray: ⊖ ⊖• Panoramic x-ray of the mandible: lytic lesion

of the body of the mandible near the angle

References:

• Schwartz’s Principles of Surgery, 8th ed.• Sabiston Textbook of Surgery, 18th ed. • http://www.carleconnect.com/CSP/CSP

%20Fall/7.%20Fall06.Brockenbrough.OralCancers.pdf

• http://www.lib.uiowa.edu/commons/oto/iowa/Part3/P3G3.htm