The significant correlation of SSTR2 expression levels with in vivo uptake of 68Ga-DOTA-peptide indicates that this imaging modality may be used as a noninvasive marker to select patients for PEN-221 treatment, monitor its response and possibly surveillance of NPC, surgical and radionuclide therapy planning and as an application for intraoperative navigation systems via integration of functional imaging data. The gene discussed is SSTR2; the disease is nasopharyngeal carcinoma.