Abstract: | Hepatectomy is one of the main treatments for hepatocellular carcinoma (HCC). However, because microscopic tumor residues are often present after surgery, the recurrence rate of HCC remains extremely high. A multimodality imaging‐guided multifunctional nanoparticle, indocyanine‐green–gadolinium–copper sulfide@bovine‐serum‐albumin–epithelial‐cell‐adhesion molecule (EpCAM), is developed for HCC treatment based on a novel theranostic strategy. After intravenous injection of these nanoparticles into HCC‐bearing mice, remarkably selective accumulation and highly efficient retention of the nanoparticles in tumor sites are observed. This is due to the EpCAM's specific targeting ability, which also results in enhanced HCC contrast in a tri‐modal visualization, which unites magnetic resonance, photoacoustic, and fluorescence imaging. Moreover, nanoparticle uptake into the HCC allows photothermal therapy (PTT) as an interoperative adjuvant strategy for further eliminating possible microscopic residues and boosting HCC surgery outcomes. This theranostic strategy not only helps with precise diagnosis of HCC but enables intraoperatively imaging guidance for accurate tumor resection. Moreover, postoperation longitudinal observation demonstrates that intraoperative imaging‐guided resection alongside a PTT‐integrated treatment strategy can result in a significant improvement of overall survival rate. These multifunctional EpCAM‐targeting nanoparticles may respresent a novel theranostic strategy to improve postsurgical HCC treatment. |