A randomized phase II study for medically inoperable stage I non-small cell lung cancer where stereotactic body radiotherapy in three fractions to 66 Gy is compared with conventionally fractionated radiotherapy to 70 Gy in 35 fractions.

This is a multicenter Scandinavian randomized phase II study of stereotactic hypofractionated radiotherapy with body frame versus conventionally fractionated radiotherapy for stage I medically inoperable non-small cell lung cancer patients. There is a 1:1 randomization between arm A: Stereotactic radiotherapy to a dose of 66 Gy with 22 Gy per fraction at the isocenter (45 Gy covers the PTV) in 3 fractions during one week with body frame fixation and a planning target volume with a 5 mm margin around the macroscopic tumour, and arm B: Conventionally fractionated radiotherapy to a dose of 70 Gy with 2 Gy per fraction in 35 fractions during 7 weeks with fixation in a vacuum pillow and a planning target volume with a 2 cm margin around the macroscopic tumour.

Inclusion Criteria:

• Non-small cell lung cancer stage I: T1-2 N0 M0.
• Medically inoperable patients or patients refusing surgery.
• Morphologically verified. If that is impossible there must be increased tumour size in repeated CT scans and positive PET.
• Patients should have a life expectancy of > 6 months.
• WHO performance status 0-2.
• Signed written informed consent obtained.
• Patient should be feasible for both study arms.

Exclusion Criteria:

• Patients with central tumour growth adjacent to trachea, main bronchus or esophagus.
• Maximal tumour diameter > 6 cm.
• Patients with prior malignancy within the last five years (except basal cell carcinoma of the skin or in situ carcinoma of the cervix).
• Any prior antitumoral treatment of the present lung cancer.
• Previous irradiation that included part of the lung.
• Pregnant women.