Case Report: Adjuvant radiation therapy for cardiac intimal sarcoma with long-term disease control.

Cardiac intimal sarcomas (CIS) are rare, aggressive primary cardiac malignancies with limited data guiding adjuvant treatment. We report a case of a 40-year-old woman with bi-atrial CIS who underwent bi-atrial resection and mitral valve replacement, with pathology confirming an MDM2-amplified intimal sarcoma and positive margins (R1). She received four cycles of adjuvant chemotherapy followed by adjuvant radiation therapy (RT) delivered using volumetric modulated arc therapy (VMAT), planned with four-dimensional computed tomography to account for respiratory motion, to a total dose of 60 Gy with a 6-Gy sequential boost. Treatment was well tolerated, with only grade 1-2 acute toxicities that resolved by completion of therapy. At 33 months following completion of RT and 41 months from diagnosis, the patient remains alive and disease-free without evidence of recurrence or significant late toxicity. This case supports the feasibility of incorporating adjuvant RT into a multimodal treatment approach for CIS and suggests that advanced radiation planning techniques may allow safe delivery of curative-intent doses to the heart, although further studies are needed to define its role in this rare malignancy.