Somatostatin receptor imaging in small cell lung cancer

To determine its usefulness, we evaluated 111In-DTPA-Octreotide (octreotide scintigraphy) in the initial staging of 19 patients with histologically proven small cell lung cancer (SCLC) and compared the results to those of conventional imaging. Images performed during initial staging demonstrated 21 known pulmonary lesions and two known supraclavicular nodes. We detected a previously unknown mediastinal lesion. The number of metastases was underestimated, with no liver (5), brain (1) or skin metastases detected. Bone lesions were identified in 4 out of 5 patients. There were fewer lesions detected with octreotide scintigraphy than with bone scintigraphy (except for one case). We therefore conclude that octreotide scintigraphy is a highly effective method for detecting SCLC primary tumour and supraclavicular nodes; the procedure is of limited value for distant metastasis. Further studies are needed to establish its ability for detecting residual intrathoracic disease, and confirm the value of octreotide scintigraphy in differentiating residual disease from other benign lesions.