Treatment of early disease (T1 and early T2) by either surgery or radiation gives equivalent survival rates. However, most lesions are conveniently treated by surgery which is generally preferred by patients. Advanced disease (late T2, T3, T4 or clinically positive neck node) is best treated by surgery followed by post-operative radiotherapy.

The aim of surgical treatment is excision of the primary tumour with a 1-2 cm margin, with tumour clearance confirmed by frozen section. For access to posteriorly located tumours, lower cheek flap or mandibular swing (median mandibulotomy) may be required. Reconstruction of the surgical defect after resection of a large tumour may require a latissimus dorsi myocutaneous flap, pectoralis major myocutaneous flap or a free forearm flap with microvascular anatomosis of the radial artery and forearm vein to the recipient neck vessels (Figs 20.14 and 20.15). Surgical treatment of clinically positive neck nodes requires comprehensive neck dissection in the form of radical neck dissection or modified radical neck dissection. Radical neck dissection is en bloc removal of lymph node-bearing tissues in the submental, submandibular, upper jugular, mid-jugular, lower jugular and posterior triangle region along with the sub-mandibular gland, internal jugular vein stern-ocleidomastoid muscle and the spinal accessory nerve.

Modified radical neck dissection differs from radical neck dissection in that the spinal accessory nerve is preserved to maximize shoulder function. The use of selective neck dissection in the form of supraomohyoid neck dissection (en bloc removal of submental, submandibular, upper- and mid-jugular node-bearing tissues) is limited to the management of a clinically negative neck, and confirmation of microscopic disease on frozen section generally requires conversion to a comprehensive neck dissection. The complication rate of radical neck dissection, even in the previously irradiated neck, is low and may include wound haematoma, wound infection, flap necrosis and, rarely, carotid artery

Figure 20.14. Free forearm flap based on the radial artery.
Figure 20.15. Reconstruction of a surgical defect of the floor of the mouth by free forearm flap.

rupture. When a myocutaneous or free flap is used for the reconstruction of oral cavity defect, orocutaneous fistula and partial or complete flap necrosis may occur.

Induction chemotherapy with 5-fluorouracil and cis-platinum may make surgical resection of a locally advanced tumour possible; concurrent chemotherapy and radiotherapy may also be of benefit to locally advanced tumour.

Typical 5-year survival rates for early disease (Stages I and II) is 60-80% and advanced disease (Stages III and IV) is 20-40%.

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