A Review of the Place and Role of Radiotherapy in Thymoma

Thymomas, tumors that arise from the epithelial cells of the thymus gland, are the most common tumors of the anterior mediastinum despite their overall rarity. They are not classified together with malignancies although it is recognized that they can be invasive and persistent even after attempted treatment. Because of their rarity, optimal treatment protocols remain a challenging topic. Although surgery is recognized as the cornerstone of management, the role and benefit of use of postoperative radiotherapy (PORT), remains questionable. Unequivocal evidence, although exclusively from retrospective studies, indicates that stage I thymoma is adequately treated with complete resection alone. As for stage II there is still a need to better determine the indications of PORT. For stage III and IV, existing data point to the fact that PORT plays a significant role in the management of thymoma. In patients for whom radiotherapy (RT) is indicated, 50 Gy appears to be adequate for microscopic disease and higher doses should be used for macroscopic tumor. With advances in RT delivery techniques, which allow for higher doses to be delivered to larger areas affected by tumor while sparing normal tissue, it is prudent to identify a place for this modality in the optimal management of thymoma patients.