Increased activity on In-111 octreotide imaging due to radiation fibrosis

Indium-111 octreotide scintigraphy is a useful investigation in the diagnosis and staging neuroendocrine or nonendocrine malignancies such as carcinoid, granulomas, small cell lung cancer, medullary thyroid carcinoma, and others. Tumors with large numbers of somatostatin receptors can be accurately imaged and this can be useful in guiding treatment. Although uncommon, false-positives studies have been reported and often the cause is unexplained but assumed to be a high number of somatostatin receptors in other pathology. We present a case with increased uptake resulting in a scan due to pulmonary fibrosis.