An Updated Review on Radiation Treatment Management in Thymus Cancers

This narrative review aims to summarize the currently available evidence for the role of radiation in the treatment of thymus cancers. Thymus cancers are rare, heterogeneous tumors with limited evidence to guide their clinical management. There remains some controversy over the role of radiation in the adjuvant and induction/definitive setting. We performed a systematic search of the MEDLINE/PubMed database, focusing on studies published within the last 30 years. Our search queried "thymoma [OR] thymic carcinoma [AND] radiation" and was limited only to prospective and retrospective studies and metanalyses, omitting books, documents, and reviews. Our search resulted in 174 total references, of which only 31 references were within the scope of interest ranging from 1988 to 2021. For resectable disease, there is prospective evidence to support the avoidance of postoperative radiation (PORT) in completely resected Masaoka stage I thymoma, but there is a lack of prospective evidence guiding the use of PORT in other situations. Several retrospective studies and metanalyses have suggested a benefit with PORT for positive margins and advanced stage disease, although it remains controversial whether PORT is beneficial for all completely resected Masaoka stage II thymoma. For unresectable disease, induction chemotherapy followed by reassessment of resectability is the preferred management. Prospective evidence exists to support the use of induction chemoradiation for patients unable to tolerate anthracycline-based chemotherapy and the use of definitive chemoradiation for those unable to undergo surgery. An effective multidisciplinary approach is the optimal strategy for achieving the best outcomes in patients with thymus cancers.