FDG-PET imaging for the staging and follow-up of small cell lung cancer

The staging procedures for small cell lung cancer do not differ appreciably from those for other forms of lung cancer. For practical pul poses, the TN M stages are usually collapsed into a simple binary classification: limited disease and extensive disease. This study was performed to answer the ques tion of whether fluorine-18 labelled 2-deoxy-2-D-glucose positron emission tomography (FDG-PET) imaging permits appropriate work-up (including both pr imary and follow-up staging) of patients presenting with small cell lung ca ncer, as compared with currently recommended staging procedures. Thirty-six FDG-PET examinations were performed in 30 patients with histologically pro ven small cell lung cancer. Twenty-four patients were examined for primary staging while four were imaged for therapy follow-up only. Two patients und erwent both primary staging and up to four examinations for therapy follow- up. Static PET imaging was performed according to a standard protocol. Imag e reconstruction was based on an ordered subset expectation maximization al gorithm including post-injection segmented attenuation correction. Results of FDG-PET were compared with those of the sum of other staging procedures. Identical results from FDG-PET and the sum of the other staging procedures were obtained in 23 of 36 examinations (6x limited disease, 12x extensive disease, 5x no evidence of disease). In contrast to the results of conventi onal staging, FDG-PET indicated extensive disease resulting in an up-stagin g in seven patients. Tn one patient in whom there was no evidence for tumou r on conventional investigations following treatment, FDG-PET was suggestiv e of residual viability of the primary tumour. Furthermore, discordant resu lts were observed in five patients with respect to lung, bone, liver and ad renal gland findings, although in these cases the results did not affect st aging as limited or extensive disease. Moreover, FDG-PET appeared to be mor e sensitive for the detection of metastatic mediastinal and hilar lymph nod es and bone metastases. Finally, all findings considered suspicious for tum our involvement on the other staging procedures were also detected by FDG-P ET. It is concluded that FDG-PET has potential for use as a simplified stag ing tool for small cell lung cancer.