Individual Boosting in Non-Small Cell Lung Cancer Using Hypofractionation, Intensity-modulated Radiation Therapy and Respiratory Gating

Overview

Patients who have inoperable non-small cell lung cancer are presently treated with chemotherapy and radiation therapy. Despite this combined approach, the vast majority of patients will have their cancer recur after treatment. A recurrence is not curable at this time. Because of the sensitivity of surrounding structures to chest irradiation, it has not been possible to give radiation doses that can cure many of these tumors. Intensity-modulated radiation therapy is a special form of radiotherapy delivery that allows doctors to reduce the amount of radiation dose to normal tissues and therefore reduce side effects. The reduction of radiation side effects may allow more radiation to be delivered to tumors, therefore improving tumor control and possibly longevity of patients. The purpose of this study is to determine whether the combination of custom designed intensity-modulated radiotherapy (based on individual tumor anatomy) with regular chemotherapy, will be safe enough to allow further intensification of radiation treatment.

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.