Stereotactic body radiation therapy for early non-small cell lung cancer.

For patients with early stage non-small cell lung cancer (NSCLC) unsuitable for resection local high-dose radiotherapy is the treatment of choice. In modern series even with escalated conformal radiotherapy local control rates of about 55% remain disappointing. Within the last years, stereotactic radiotherapy has been shown an effective treatment approach for early stage malignant lung tumors, combining the accurate focal dose delivery by stereotactic techniques with the biological advantages of dose escalated hypofractionated radiotherapy. Typical treatment regimens include three to five fractions over 1-2 weeks or 1 single fraction as radiosurgery. With adequate staging procedures including FDG-PET-CT scan and a low probability of subclinical involvement of unsuspicious locoregional lymph nodes, the concept is to irradiate the primary T1/2 tumor alone. Recent data report local control rates of up to 90%, with favorable results especially for patients in good general condition. Less than 10% of all patients develop isolated tumor recurrences in regional lymph nodes. Three-year survival is significantly improved to more than 80% when biological effective doses of more than 100 Gy are applied to patients in good conditions. Systemic tumor recurrence still is a major problem, making an additional systemic chemotherapy interesting for selected patients after hSRT, such as those younger than 75 years.