Role of radiotherapy in thymoma and thymic carcinoma: a narrative review

Thymic epithelial tumors, comprising thymoma and thymic carcinoma, are rare and heterogeneous neoplasms for which high-level evidence is limited. Radiotherapy is integral across the disease continuum-from postoperative settings to definitive therapy for unresectable tumors and oligometastatic/recurrent disease. This narrative review synthesizes contemporary evidence and guidance on indications, technique, dose prescription, outcomes, and toxicity, with focused discussion of hypofractionation and stereotactic body radiotherapy (SBRT).

A comprehensive PubMed search (1 November 2025) combined MeSH and free-text terms for thymic tumors and radiotherapy without date restriction. English-language human studies of any design were eligible. Titles/abstracts and full texts were screened independently by the author; reference lists of key studies and recent reviews were hand-searched to ensure completeness.

For completely resected early-stage thymoma, surgery alone often suffices, whereas postoperative radiotherapy (PORT) is generally favored for positive margins (R1/R2), advanced stages (III-IV) and unfavorable pathological finding. Meta-analyses increasingly suggest overall survival benefit from PORT in stage III-IV thymoma and in thymic carcinoma, with more variable findings for stage II disease. In thymic carcinoma, multi-institutional series demonstrate a clearer association between PORT and improved survival. For unresectable disease, concurrent chemoradiation using modern conformal techniques achieves high response rates and meaningful survival. Dose recommendations across international guidelines converge on 45-50 Gy (R0), 50-54 Gy (R1), and 60-70 Gy (R2), with elective nodal irradiation generally discouraged.

Current data support PORT for high-risk features and thymic carcinoma, definitive chemoradiation for unresectable disease, and carefully selected use of hypofractionation/SBRT for limited recurrences. Priorities include randomized evaluation of PORT in borderline settings, harmonized reporting of toxicity and quality of life, and prospective study of modality selection to optimize cure while minimizing late effects.