Lung cancer is highly prevalent, and the leading cause of cancer related death throughout much of the world. The CyberKnife System is technically capable of treating tumours anywhere in the lung with high accuracy. Its clinical application currently includes primary treatment for early stage (I and II) non-small cell lung carcinoma (NSCLC), boost treatment for residual disease following chemoradiation for stage III NSCLC, and treatment of lung metastases. Stereotactic Radiotherapy has the potential to produce high local control rates with low risk of severe lung toxicity.
In stage I non-small-cell lung cancer (NSCLC) standard treatment is still surgery, in younger patients sometimes followed by systemic chemotherapy. For those patients in early NSCLC stages with pre-existing co-morbidity, advanced age or refusal of operation definitive radiation therapy alone may be the standard treatment option. High biologically effective radiation doses are generally of advantage with regard to tumour cell kill and local tumour control. Patients with clinically T1-2 N0-tumours seem to be the ideal candidates for CyberKnife hypofractionated Stereotactic Radiosurgery (hSRS). Initial data report on local control rates of up to 90%, with favourable results especially for patients who are otherwise in good general condition.