The goal of our study was to determine if lymph node activity could be visualized using a hybrid single-photon emission computed tomography/computed tomography ( SPECT/CT ) scanner with two commonly used colloidal lymphatic radiotracers -- 99mTc-antimony sulfide colloid ( ASC ) and 99mTc-filtered sulfur colloid ( FSC ) in the setting of low-stage non-small cell lung cancer ( NSCLC ) .