Multiple randomised trials and meta-analyses which have demonstrated the superiority of concurrent chemoradiation (CRT) when compared to radiotherapy (RT) alone.r
The international standard schedule is 70Gy in 35 fractions with concurrent high-dose intermittent cisplatin.r
Altered fractionation ± cetuximab is an alternative for patients not medically fit for concurrent chemotherapy.r
Human papillomavirus (HPV)
The incidence of HPV related oropharynx SCC is increasing. These patients have a different profile to HPV unrelated head and neck SCC. HPV positive tumours carry a better prognosis than HPV negative tumours.rr This can be mitigated by their smoking history.r
At this stage there is no evidence to support treatment de-escalation in HPV positive patients and we await the results of de-intensification trials.
Peters et al. 2010 reported on the impact of radiotherapy quality on patient outcomes in a large international phase III trial (TROG 02.02).r In patients with major deficiencies in their radiotherapy treatment plan there was a significantly inferior outcome; 2-year overall survival of 50% vs 70%; hazard ratio (HR), 1.99; P< .001; and 2-year freedom from locoregional failure, 54% v 78%; HR, 2.37; <P .001, respectively. These results show the critical importance of radiotherapy quality on outcome of chemoradiotherapy in locally advanced head and neck cancer.
Unilateral treatment of the neck is the preferred treatment in patients with T1-2N1 (AJCC 7th edition, i.e. those with a solitary lymph node <3cm)r well-lateralised tonsillar tumours (i.e. no soft palate or base of tongue extension).r Unilateral treatment may be appropriate for, but should be used selectively in patients with: (1) <1cm extension of the tonsillar tumour onto either the soft palate or base of tongue; and/or (2) a single lymph node >3cm but <6cm, (AJCC 7th edition N2a)r or multiple small volume lymph nodes (AJCC 7th edition N2b)r. This approach is endorsed by the ASTRO consensus guidelines.r
The decision of treating unilaterally should be made on anatomical staging, not on p16/HPV status.
The Princess Margaret Hospital recently updated their results of unilateral treatment in well lateralised tonsil tumours in the HPV era.r Unilateral treatment was administered to 102 patients, and HPV status was known in 96 (62 HPV+, 34 HPV-). Only 8 N2b patients were treated unilaterally and all had low volume disease (≤3 lymph node metastases). Only two patients from the unilateral group received concurrent chemotherapy. Contralateral neck failure occurred in only two patients, one HPV+ and HPV-, and both were successfully salvaged.
Other series similarly low rates of contralateral neck failure, and a contemporary review of published studies reporting unilateral treatment outcomes for oropharyngeal cancers reports low rates of contralateral neck failure, although selection bias in the N2+ group is highly likely and should be interpreted with caution.rr
Figure 2.0. Schematic diagram depicting “very-lateralized” primary suitable for consideration of ipsilateral radiation therapy.r