Application of Real-Time Indocyanine Green Fluorescence Imaging in Recurrent Nasopharyngeal Carcinoma Surgery.

BACKGROUND

Indocyanine green (ICG) fluorescence imaging enhances cancer surgery precision, showing great potential for resection of tumors such as liver cancer. Although early-stage recurrent nasopharyngeal carcinoma (rNPC) can be surgically removed, residual tumors hinder effectiveness. The application of ICG fluorescence imaging in precision surgery for rNPC has been rarely reported. To the authors' knowledge, this video is the first to document clinical practice using real-time ICG green fluorescence imaging for the surgical treatment of rNPC.

METHODS

A 74-year-old man was admitted with left-sided nasal congestion for 3 months, 9 months after comprehensive treatment for NPC. Nasal endoscopy indicated a lesion in the left middle and lower nasal passage, and laboratory tests showed positive Epstein-Barr virus (EBV) DNA with a quantitative result of <5.00E+02 (copies/ml). Enhanced MRI of the nasopharynx showed a lesion in the left middle and lower nasal passage, with marked contrast enhancement, suggesting a recurrence of nasopharyngeal carcinoma. Indocyanine green fluorescent dye (0.4 mg/kg) was injected into the elbow vein 24 h before surgery, and an additional 5 mg was administered intraoperatively (Fig. 1). Intraoperatively, fluorescence imaging demonstrated significant fluorescence accumulation in the nasal and nasopharyngeal tumors. Under real-time imaging guidance, the tumor and its base were precisely resected.

RESULTS

The histopathologic diagnosis indicated non-keratinizing undifferentiated carcinoma. In situ hybridization showed EBV-encoded small RNAs (EBER+). Real-time fluorescence imaging detected no positive margins in the submitted specimens. A postoperative EBV recheck showed levels below the detection limit.

CONCLUSION

Surgery for rNPC guided by real-time ICG fluorescence imaging is feasible and effective. Fig. 1 Illustration showing the application of real-time indocyanine green fluorescence imaging during endoscopic nasal surgery. A ICG is injected intravenously 24 hours before operation at a dose of 0.4 mg/kg, and an additional 5 mg was administered intraoperatively. B Nasal endoscopy revealed green fluorescence imaging of the nasopharyngeal mass. PR：pharyngeal recess, NPW: nasopharynx posterior wall, TT: torus tubalis, SP: soft palate.