Scintigraphic imaging of small-cell lung cancer with [111In]pentetreotide, a radiolabelled somatostatin analogue

Abstract

Recent work suggests that between 50 and 75% of small-cell lung cancer (SCLC) tumours have specific high-affinity binding sites for somatostatin. This study evaluated the potential role of the radiolabelled somatostatin analogue, [111In]pentetreotide, in the detection and staging of SCLC in patients prior to and after chemotherapy using scintigraphic imaging techniques. Thirteen patients were studied prior to chemotherapy. Following standard staging six patients had limited stage disease and seven extensive disease. [111In]pentetreotide imaging led to the detection of all primary sites of disease, including a primary site of disease not detectable with chest radiograph or computerised tomography (CT) of the thorax. Five of ten metastatic sites detected by standard staging were also imaged. Furthermore, a cerebellar metastasis was detected in a patient thought to have disease confined to the right hemithorax. This was subsequently confirmed with a CT brain scan. Following chemotherapy [111In]pentetreotide imaging detected residual intrathoracic disease in two of three patients with complete remissions by standard staging and in two patients who had had a partial response to chemotherapy. These results suggest that [111In]pentetreotide imaging may have a role to play in the clinical evaluation of patients with SCLC. Specifically, this technique may be of particular value in detecting residual intrathoracic disease in patients thought to be in complete remission by conventional staging methods. Images Figure 1 Figure 2 Figure 3

Somatostatin, Its Receptors and Analogs, in Lung Cancer

“…Disease was downstaged in 4 out of 7 patients with extensive disease and upstaged in 1 patient with limited disease. In summary, [ 111 In]pentetreotide detected secondaries in 4 or 50% of the 8 patients found to have metastases at the completion of all investigations [81].…”

“…The patient subsequently relapsed at this site. Therefore the technique may allow a more accurate assessment of prognosis for the individual patient following completion of chemotherapy and aid subsequent management decisions [81].…”

Octreotide scintigraphy for small cell lung carcinoma: Past, present or future?

“…Especially in the follow-up after treatment it is important to be able to differentiate residual disease from infection or other benign entities. Although Maini et al [15] and O'Byrne et al [16] have suggested the possibility of detection of residual intrathoracic disease, this could not be confirmed by Kirsch and co-workers in their article in this issue. It is to be expected that any type of therapy will influence the results of octreotide scintigraphy because of the reduction in receptor density.…”

“…Since MRI seems to be more sensitive than bone scintigraphy in the detection of metastases in the spine, pelvis and sternum, this modality might be performed in patients with a normal bone scintigram and further proof of limited disease [20]. In 50% of the patients with known skeletal metastases O'Byrne et al [16] demonstrated uptake of 11qn_octreotide, but in these patients there was still a discrepancy between findings on bone and octreotide scintigraphy. In view of the high sensitivity and low cost, it seems logical to use bone scintigraphy as the first step in staging this cancer.…”

OctreoTher^TM: Ongoing Early Clinical Development of a Somatostatin-Receptor-Targeted Radionuclide Antineoplastic Therapy

“…Small cell lung cancer (SCLC) comprises approximately 18% of all primary lung cancer, virtually all of the tumors bearing somatostatin receptors [5, 6, 7, 8]. Although SCLC is highly sensitive to radiation, coexistent lung tissue damage and the early occurrence of distant metastases limit the utility of external beam irradiation.…”