All patients must have a satisfactory IMRT plan prior to starting radiation therapy, which will commence concurrently with chemotherapy. All patients will be treated to a minimum of 48 Gy in 20 daily fractions over 4 weeks \[2.4 Gy per fraction (fx)\], to the planning target volume (PTV) defined by pre chemotherapy CT with PET imaging. This is approximately biologically equivalent to a dose of 54 Gy in 27# (5 fractions/week). A differential boosting will then be selected from one of 5 dose escalation schemes. The total individual radiotherapy dose will be prescribed according to the highest dose level that can satisfy all of the set radiotherapy planning constraints for the individual's anatomy. The trial will proceed in 2 phases. In the first phase only the first 3 dose escalation schedules will be used. Once all of these 3 schedules have been deemed safe then dose levels 4 and 5 will be opened up to participation.
