The role of radiation therapy in thoracic tumors

Thoracic tumors are extremely common. Lung cancer remains the number one diagnosed cancer worldwide; 1.35 million cases were diagnosed in 2002 [1]. In 2005, it is estimated that 172,570 cases of lung cancer will be diagnosed and that there will be 163,510 deaths from lung cancer in the United States [2]. There were approximately 462,000 new cases of esophageal carcinoma worldwide in 2002 [1], and there will be 14,520 new cases and 13,570 deaths from esophageal cancer in the United States in 2005 [2]. Thymic tumors are the most common tumors of the anterior mediastinum [3]. Mesothelioma, on the other hand, is a relatively uncommon tumor, but its incidence is increasing rapidly [4,5]. Radiation therapy (RT) plays a significant role in the management of thoracic tumors. Most of these tumors require RT (1) as a local measure for definitive treatment of medical inoperable or surgically unresectable disease, (2) as part of a multimodality regimen for locally advanced disease, (3) with adjuvant intent, before (neoadjuvant) or after (adjuvant) surgery, or (4) for palliation of symptoms in patients who have stage IV disease. It is estimated that more than 50% to 60% of lung cancer cases require RT at least once, with about 45% of patients receiving it as part of the initial treatment [6]. Likewise, radiation is an important treatment for more than 80% of patients who have esophageal cancer [7]. In the treatment of other thoracic tumors, such as thymoma. and mesothelioma, RT also plays an important role. This article reviews the role of RT, and some of the new advances in RT of the aforementioned thoracic diseases. Thoracic tumors such as lymphoma and other mediastinal malignancies are discussed elsewhere in this volume.