Proton beam therapy causing pericarditis – a rare case of radiation induced cardiotoxicity

Acute pericarditis is caused by the inflammation of the pericardium which can result in an effusion around the heart. Proton beam therapy causing radiation-induced pericarditis is not a well-known cause of pericarditis. We present a case of a patient with Li-Fraumeni Syndrome who developed acute onset pericarditis, presumed to be secondary to proton beam therapy.