Indium-111-DTPA-octreotide Scintigraphy Modulation by Treatment with Unlabelled Somatostatin Analogue in Smali-Cell Lung Cancer

Abstract

Aims and background

Small-cell lung cancer (SCLC) tissue expresses somatostatin receptors and can be visualized by means of the indium-111-labelled somatostatin analogue DTPA-D-Pheoctreotide. The aim of the study was to investigate whether treatment with a cold somatostatin analogue can affect the imaging of somatostatin receptor scintigraphy.

Methods

Three patients with SCLC were treated with 200 μg of cold octreotide three times a day subcutaneously for 7 days. Whole body and planar scintigraphy was performed before and after the treatment.

Results

¹¹¹In-DTPA-octreotide uptake was increased in cancer lesions, whereas fixation in normal tissues (liver, spleen, kidneys) decreased.

Conclusions

This is the first demonstration of an enhancement of SCLC imaging following unlabelled somatostatin analogue administration. Similar results have been described by other authors in a limited number of carcinoid tumors.