• Swallowing Quality of life [ Time Frame: Baseline up to 12 months ]
  Assessed with the MD Anderson Dysphagia Inventory (MDADI) scale
• Swallowing Quality of life [ Time Frame: Baseline up to 12 months ]
  Assessed with the EORTC QLQ-C30 scale
• Swallowing Quality of life [ Time Frame: Baseline up to 12 months ]
  Assessed with the EORTC QLQ H&N 35 scale
• Health Status Quality of life [ Time Frame: Baseline up to 12 months ]
  Assessed with the EORTC EQ-5D-5L scale
• Overall survival [ Time Frame: Baseline to 5 years ]
  Defined as time from randomization to death from any cause
• Disease free survival [ Time Frame: Baseline to 5 years ]
  Defined as the measure of time after treatment during which no sign of cancer is found
• Local recurrence [ Time Frame: Baseline to 5 years ]
  Defined as Cancer that has recurred at or near the same place as the primary tumor, usually after a period of time during which the cancer could not be detected.
• Regional recurrence [ Time Frame: Baseline to 5 years ]
  Defined as recurrence that occurs in the lymph nodes and tissue located in the vicinity of your original cancer
• Locoregional recurrence [ Time Frame: Baseline to 5 years ]
  Defined as the recurrence of cancer cells at the same site as the original tumor and/or the regional lymph nodes after a disease free period.
• Rate of salvage treatment (surgery +/- radiotherapy) in the pN0 neck and freedom from unsalvageable neck recurrence [ Time Frame: Baseline 5 years ]
  Rate of salvage treatment (surgery +/- radiotherapy) in the pN0 neck and freedom from
• Rate of feeding tub insertion and rate of feeding tube use at 1-year post randomization [ Time Frame: Randomization to 1 year post randomization ]
  Rate of feeding tub insertion and rate of feeding tube use at 1-year post randomization
• Swallowing function [ Time Frame: Baseline to 1 year ]
  Measured by the Modified Barium Swallow Impairment (MBsimp) score
• Swallowing function [ Time Frame: Baseline to 1 year ]
  Measured by the Dynamic Imaging Grade of Swallowing Toxicity score
• Swallowing function [ Time Frame: Baseline to 1 year ]
  Measured by the Functional Oral Intake Score
• Rate of toxicity [ Time Frame: Baseline to 5 years ]
  Assessed using the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 4
• Rate of failure in the clinically node negative neck [ Time Frame: Baseline to 5 years ]
  defined as time from randomization to failure in the cN0 neck

The goal of this randomized treatment study is to formally compare quality of life in patients with at least one pN0 hemi-neck after resection of a squamous cell carcinoma of the oral cavity treated with a primary radiation therapy versus a secondary targeted radiation therapy approach, to provide a high level of evidence to guide the selection of treatment options.

The study will require a sample size of 90 patients randomized in a 2:3 between the two arms. Arm 1 (standard radiation therapy to tumor location and surrounding area) and Arm 2 (targeted radiation therapy to tumor location).

Patients will be followed for a total of 5 years.

• Radiation: Radiotherapy to all dissected areas
  Post operative radiation therapy +/- chemotherapy based on historic treatment volumes (including the primary site, dissected areas +/- elective areas
• Radiation: Omit radiation to pN0 neck
  post operation radiation therapy +/- chemotherapy that avoids targeting the dissected pN0 neck

• Active Comparator: Standard Radiotherapy
  Radiotherapy to all dissected areas
  Intervention: Radiation: Radiotherapy to all dissected areas
• Experimental: Radiotherapy to smaller treatment area
  Omit radiation to pN0 neck
  Intervention: Radiation: Omit radiation to pN0 neck

Inclusion Criteria:

• Willing to provide informed consent
• ECOG performance status 0-2
• Histologically confirmed, resected oral cavity squamous cell carcinoma with at least ipsilateral selective neck disection
• Patient has pathological features that are indications for PORT: positive or close (≤ 3 mm) margin, presence of LVI or PNU, pT3 or pT4 disease, positive lymph nodes, and PORT is recommended by treating physician
• Pathologically lympth node negative in at least one dissected hemi-neck with at least 10 nodes recovered in each pN0 hemi-neck

Exclusion Criteria:

• Serious medical comorbidities or other contraindications to radiotherapy
• Prior history of head and neck cancer within 5 years
• Any other active invasive malignancy, except non-melanotic skin cancers
• Prior head and neck radiation at any time
• Prior oncologic head and neck surgery in the oral cavity or neck
• Metastatic disease
• Locoregional disease recurrence identified following surgical resection but prior to the start of radiotherapy
• Inability to attend full course of radio therapy or follow-up visits
• Unable or unwilling to complete QoL questionnaires
• Pregnant or lactating women