The role of radiation therapy in the management of primary thymic epithelial neoplasms

Therapeutic radiation plays an important role in the management of thymoma and thymic carcinoma. These two tumor types differ substantially in their aggressiveness and prognosis. The most pressing issue in radiotherapy is which thymoma and thymic carcinoma patients need radiation. Given that these are rare cancers, few randomized trials have been published. Controversy remains regarding which patients benefit from adjuvant radiation therapy. Existing literature spans patients treated over nearly 50 years, during which time radiation therapy has evolved from rudimentary 2-dimensional based planning to conformal 3-dimensional planning to yet more conformal dose painting techniques such as intensity-modulated radiation therapy and proton therapy. If the effect of radiation is small and the natural history of a disease long, as is the case for stage I favorable histology thymoma, then differences in techniques and toxicities may have as much of an impact as whether radiation was given or not.