Hypofractionated stereotactic radiotherapy for medically inoperable stage I non-small cell lung cancer--report on clinical outcome and dose to critical organs.

We report 20 cases using hypofractionation stereotactic radiotherapy in medically inoperable stage I non-small cell lung cancer with dose escalation of 45-54 Gy prescribed at 85 or 90% isodose level in 3-4 fractions. Two-year local control and cancer-specific survival were 94.7 and 77.6%, respectively, with minimal toxicity. Though, large fraction size can be safely given to peripheral lung tumors, normal tissue tolerance to hypofractionated radiotherapy to esophagus, trachea, main bronchi, aorta and heart remains unknown. Therefore we also reported the maximum point doses to these critical organs to contribute information to extend this technique to more centrally located lung tumors in future.