2) Radiotherapy

Primary Radiotherapy

Primary radiotherapy is usually reserved for:

  • Patients who are inoperable due to medical reasons (eg. severe cardiac or respiratory disease)
  • Pateints for whom surgery would result in undesirable morbidity (eg. T4 tumour requiring laryngectomy)
  • Patients who refuse surgery

Conventional dosing in 2 Gy fractions is:

  • 70 Gy to macroscopic disease
  • 60 Gy to 'high risk' areas that are not involved with macroscopic disease, for instance clinically negative level II nodes
  • 50 Gy to 'low risk' areas, such as level IV nodes in a node negative neck.

Adjuvant Radiotherapy

Many patients undergo surgical excision as primary treatment, but in many cases radiotherapy is used to improve cure rates. The classical schedule, in 2 Gy fractions, is:

  • 60 Gy to surgical sites (primary and neck dissection if involved)
  • 50 Gy to uninvolved nodal sites
  • 70 Gy to residual macroscopic disease (eg. tumour unable to be completely removed macroscopically)
  • 66 Gy to residual microscopic disease (eg. positive margins)

If IMRT is used then the lower doses must be adjusted to account for the longer time period. For instance, if 60 Gy and 50 Gy are used, then the 50 Gy dose should be increased by 3 - 4 Gy to account for less dose per fraction (eg. 54 Gy in 30 fractions).

Adjuvant Chemoradiotherapy

For patients with stage III or IV tumours, two studies have shown improved outcomes with addition of cisplatin:

  • RTOG 9501 (Cooper et al) - Published in 2004, compared radiotherapy (60-66 Gy) with or without cisplatin on days 1, 22, and 43. Disease free survival was improved (hazard ratio 0.61), overall survival was not (hazard ratio 0.84, p=0.19), and there were increased early effects in the combined group (34% versus 77%). Four patients died in the concurrent arm.
  • EORTC 22931 (Bernier et al) - Also published in 2004. Compared 66 Gy of radiotherapy with or without cisplatin in a similar protocol to the RTOG 9501. This demonstrated improved disease free survival (hazard ratio 0.75, p=0.04); improved overall survival (hazard ratio 0.70, p=0.02); and a 5 year survival improvements (53% versus 40%). Side effects were greater in the concurrent group (41 versus 21%). Late effects were similar.

The summary of these studies are that for locally advanced head and neck cancers, adjuvant chemoradiotherapy promises improved survival at the expense of increased acute toxicity and potential for death.

Palliative Radiotherapy

In some cases a patient may present with metastatic disease and be incurable. Other patients may be unable to tolerate extensive treatment due to other health concerns. In these cases, local control is important but doses can be reduced to preserve quality of life. Two reasonable fractionation schemes are:

  • 36 Gy in 6 fractions (6 Gy per fraction, 2 fractions per week)
  • Quad Shots (14 Gy in four fractions over 2 days; repeated 3 times, each course separated by one month (total 42 Gy/12 #))

Quad shots are particularly useful for frail patients with a very limited life expectancy or from rural settings. They can be admitted overnight for the treatment. The prescribed dose is low enough to avoid significant early reactions and the length of time between treatments permits healing of normal tissues. It allows them to remain at home or in their usual environment.


Patients should be simulated supine with a head rest and thermoplastic mask. A custom bite block should be inserted to separate the tongue from the hard palate and reduce the volume of nasal cavity that is irradiated.
A common problem with head and neck treatments is patients with short necks and/or high shoulders. Patients should lower their shoulders by pulling on a tension device that loops beneath the feet.


Fields are still in frequent use throughout the world although IMRT techniques are replacing this method. Treatment volumes depend on the extent of disease. Two sets of fields are used; an upper pair of opposed lateral fields and bilateral anterior fields directed to the supraclavicular fossae. This requires a junction between the fields; usually the isocentre is placed at the thyroid notch to ensure that the junction does not pass through the primary tumour. In some cases this junction must be feathered to avoid under-dosing of macroscopic tumour in nodes.

  • The oral cavity and upper cervical lymph nodes are treated with opposed lateral fields. This field should cover levels IA/B, II and the upper part of level III. The borders are:
    • Superior: 1.5 cm superior to tumour extent (anteriorly); External auditory meatus (posteriorly, to cover superior part of level II)
    • Inferior: The isocentre
    • Anterior: 1 cm anterior to the alveolar ridge (can be reduced if the tongue tumour is in the posterior part of the anterior tongue)
    • Posterior: Midway through the vertebral bodies of the cervical spine. For patients with a large primary, N2 neck disease or involved level V nodes, this border is moved posteriorly to the posterior extent of the C1 spinous process.
  • Level IV and the lower part of levels III and V are covered by single supraclavicular fields. A space between these fields reduces dose to the spinal cord. The boundaries of the anterior fields are:
    • Superior: The isocentre
    • Inferior: The inferior border of the clavicle
    • Medial: The lateral border of the spinal canal
    • Lateral: The lateral point where the first rib and clavicle intersect

When doses over 45 Gy are delivered the spinal cord must be protected. This is done by using a two phase technique for the upper, lateral fields. Once 40 Gy is reached, the upper field is split into an anterior photon field and a posterior electron field. The photon field should be blocked midway through the bodies of the cervical vertebrae on a DRR. Electron energies depend on the depth of the neck but are usually 12-16 MeV.


IMRT provides reduced dose to critical structures, such as parotid glands and spinal cord, and removes electron junctioning issues from planning. IMRT relies on accurate contouring of macroscopic tumour and at-risk nodal regions, as well as a well equipped department with significant physics support.