Stereotactic body radiotherapy for early lung cancer

Although the standard treatment method for stage I non-small cell lung cancer is surgery (lobectomy), many patients are inoperable due to age andor complications. Radiotherapy is often performed in inoperable patients; however, the results of conventional fractionated radiotherapy are not satisfactory. In recent years, the high efficacy and safety of stereotactic body radiotherapy (SBRT), which can be used to deliver a targeted high dose to the tumor while minimizing effects on adjacent normal tissues, have been demonstrated, and SBRT has become a standard treatment for medically inoperable patients with stage I non-small cell lung cancer in place of conventional fractionated radiotherapy. Although the high efficacy of SBRT has been reported in operable patients, the equivalence of the treatment effect compared with surgery has not been confirmed in randomized controlled trials, and a consensus regarding the optimal treatment has not been reached. In elderly subjects or marginally operable patients in whom performing lobectomy is difficult although limited surgery (segmentectomy or wedge resection) is possible, SBRT is a reasonable and less invasive treatment option with expected results equivalent to surgical intervention. However, there is not yet sufficient evidence to confirm the efficacy and safety of this treatment over long-term follow-up, and several issues, including the optimal dose and fractionation, use of adjuvant chemotherapy, diagnosis of recurrence and effectiveness of salvage treatment after recurrence, remain to be addressed.