Imaging of non-small-cell lung cancer with indium-111 pentetreotide

Purpose: Lung cancer is the leading cause of cancer deaths in the United St ates. Non-small-cell lung cancer (NSCLC) accounts for 75% to 85% of lung ca ncers. CT has been the standard anatomic study for localizing and staging N SCLC, although it is associated only with moderate accuracy. In-111 pentetr eotide, a radiolabeled somatostatin analog largely used in the scintigraphi c localization of neuroendocrine tumors, has been shown incidentally to ide ntify NSCLC lesions. This observation is important in the workup for metast atic disease for neuroendocrine tumors, because presumed metastatic lesions may actually be second primary tumors of NSCLC. In-111 may also serve as a potentially useful adjunct to CT in the anatomic evaluation of NSCLC. The purpose of this study was to determine the likelihood of detecting and loca lizing NSCLC using In-111 pentetreotide scintigraphy. Materials and Methods: Ten patients with known or possible NSCLC were exami ned using In-111 pentetreotide. Scans were compared with the patients' prev iously performed chest radiographs and CT scans. Results: In-111 pentetreotide imaging correctly identified sites of tumor i nvolvement as detected by chest CT and surgery in all 10 patients with NSCL C. Conclusion: This study demonstrates the uptake of In-111 pentetreotide by N SCLC. This important observation should be considered in the workup for met astatic disease of neuroendocrine tumors with In-111 pentetreotide, because NSCLC can be a source of false-positive findings. In-111 pentetreotide ima ging may also serve as a potentially useful adjunct to CT for identifying o bscured or equivocal lesions and as an aid in localizing tissue for biopsy.