Rationale for phase III trials of thoracic radiation therapy doses in limited-stage small-cell lung cancer.

The optimal integration of thoracic radiation therapy with systemic chemotherapy in the treatment of limited stage small-cell lung cancer remains to be defined. Although there are many unsettled issues, it has been more than 15 years since the most recent phase III Intergroup study completed accrual. In March 2008, a phase III Intergroup study assessing high-dose thoracic radiation therapy in limited-stage small-cell lung cancer was activated in the United States, and a randomized study in Europe is also investigating a thoracic radiation therapy dose escalation. The rationale for these trials is described herein.