Stereotactic body radiation therapy in lung

Lung cancer is the leading cause of cancer death worldwide, in both men and women. Contrary to the improved survival outcomes for many other types of cancers, the prognosis for people diagnosed with lung cancer remains poor, with 5-year relative survival ranging 6-18%. Majority of lung cancers diagnosed at locally advanced stage, due to the lack of observable symptoms for early stage lung cancer. Recently Lung Cancer screening in high-risk population with low dose CT scan showed 20% reduction in relative death from cancer. Screening allows diagnosing the cancer at early stage. For early (local only) stage, lobectomy is he treatment of choice that offers best 5-year overall survival of 60%. But majority of these patients are unable to tolerate the surgery due to poor pulmonary reserve or medical co morbidity. With the advent of new technology, improvements in imaging and treatment delivery enable us to extend the stereotactic radiation therapy to extra cranial sites. Stereotactic radiation therapy to lung reported 5-year local control rates in excess of 90% and overall survival of 40%. In this review article, we discussed the rationale, evidence supporting stereotactic body radiation therapy (SBRT) in lung tumors, radiobiology of hypofractionation, mediastinal staging, the treatment planning, and delivery process and also the role of SBRT in metastatic setting.