Pitfalls in radiation oncology. "Myocardial metastasis" in PET-CT after palliative radiation treatment of the left 5th rib.
ABSTRACT Positron emission tomography-computed tomography (PET-CT) is a useful diagnostic tool to detect metastases in patients with malignancy. False positives have been reported in cases of inflammation and tissue regeneration.
Over a period of 2 years, a 32-year-old woman with hepatocellular carcinoma and multiple bone metastases received three treatments of radiation therapy to a bone metastasis in the 5th left rib. Restaging with [18F]fluorodeoxyglucose (FDG) PET-CT showed increased uptake within the cardiac apex highly suspicious for a myocardial metastasis. Because the patient was asymptomatic, additional magnetic resonance imaging (MRI) of the heart was performed demonstrating radiation-associated changes but no evidence for metastases.
PET-CT is a well-established diagnostic tool in metastatic diseases but its results should always be correlated with the clinical picture of the patient and previous treatments to rule out false positives.