SCINTIGRAPHIC IMAGING OF SMALL-CELL LUNG-CANCER WITH [IN-111] PENTETREOTIDE, A RADIOLABELED SOMATOSTATIN ANALOG

Recent work suggests that between 50 and 75% of small-cell lung cancer (SCLC) tumours have specific high-affinity binding sites for somatost atin. This study evaluated the potential role of the radiolabelled som atostatin analogue, [In-111]pentetreotide, in the detection and stagin g of SCLC in patients prior to and after chemotherapy using scintigrap hic imaging techniques. Thirteen patients were studied prior to chemot herapy. Following standard staging six patients had limited stage dise ase and seven extensive disease. [In-111]pentetreotide imaging led to the detection of all primary sites of disease, including a primary sit e of disease not detectable with chest radiograph or computerised tomo graphy (CT) of the thorax. Five of ten metastatic sites detected by st andard staging were also imaged. Furthermore, a cerebellar metastasis was detected in a patient thought to have disease confined to the righ t hemithorax. This was subsequently confirmed with a CT brain scan. Fo llowing chemotherapy [In-111]pentetreotide imaging detected residual i ntrathoracic disease in two of three patients with complete remissions by standard staging and in two patients who had had a partial respons e to chemotherapy. These results suggest that [In-111]pentetreotide im aging may have a role to play in the clinical evaluation of patients w ith SCLC. Specifically, this technique may be of particular value in d etecting residual intrathoracic disease in patients thought to be in c omplete remission by conventional staging methods.