Stereotactic body radiotherapy with CyberKnife for cardiac malignancies

Radiobiological and technical considerations have traditionally limited the role of radiation therapy in the context of primary and secondary cardiac malignancies. Stereotactic body radiotherapy (SBRT) is a promising modality for the delivery of focused high-dose radiation with ablative potential to complex targets such as small, deep-seated, moving lesions, allowing also for re-irradiation.

Between January 2013 and October 2013, 3 patients underwent SBRT for cardiac lesions: 2 patients had recurrent, previously irradiated cardiac angiosarcomas (PCA) and 1 patient had a cardiac metastasis from melanoma. They were treated with fiducial-guided robotic radiotherapy with CyberKnife. As for dose prescription, 24 Gy in 3 fractions (80% isodose) and 30 Gy in 5 fractions (80% isodose) were administered to the recurrent PCAs and cardiac metastasis, respectively.

At 2 months after SBRT, cardiac MRI showed a partial response in the patients treated for recurrent PCA while the cardiac metastasis remained stable. In all cases, absence of local progression was subsequently confirmed by contrast-enhanced cardiac MRI after 6 months, without any evidence of treatment-related side effects.

Fiducial-guided SBRT proved to be feasible and effective in preventing local disease progression in selected patients with cardiac malignancies.