Evaluation of (111)In-pentetreotide, (131)I-MIBG and bone scintigraphy in the detection and clinical management of bone metastases in carcinoid disease.

Bone metastases are assumed to be rare in carcinoid disease and to be associated mainly with bronchial primaries. The aim of the present study was to evaluate the occurrence of bone metastases in patients with metastatic carcinoid tumours, and the role of various nuclear medicine modalities (bone scintigraphy, (111)In-pentetreotide and (131)I-MIBG) in its detection and clinical management. Nine (2 women, 7 men, median age 65 years) out of 86 consecutive carcinoid patients treated between 1987 and 1998 developed bone metastases (10%) with a median interval of 37 months between the diagnosis of metastatic carcinoid and bone metastases. Seven of them had non-bronchial primaries. (111)In-pentetreotide scintigraphy failed to detect the bone lesions in 50% of the cases, and (131)I-meta-iodobenzylguanidine(MIBG) scintigraphy in almost 80% of cases. Standard bone scintigraphy, however, was positive in all. Pain relief of bone metastases by means of radiation therapy was obtained in 5 of 6 patients. In another patient palliation of pain symptoms was obtained with Rhenium-186-hydroxyethylidene diphosphonate. Octreotide, Interferon of MIBG were ineffective for this purpose. It is concluded that bone metastases in carcinoid patients may be missed on (131)I-MIBG and (111)In-pentetreotide scintigraphy. Bone scintigraphy is a sensitive imaging technique. Diagnostic nuclear medicine modalities may be helpful in the clinical management of carcinoid disease.