Data from <sup>89</sup>Zr-panitumumab Combined With <sup>18</sup>F-FDG PET Improves Detection and Staging of Head and Neck Squamous Cell Carcinoma

AbstractPurpose:

Determine the safety and specificity of a tumor-targeted radiotracer (⁸⁹Zr-pan) in combination with ¹⁸F-FDG PET/CT to improve diagnostic accuracy in head and neck squamous cell carcinoma (HNSCC).

Experimental Design:

Adult patients with biopsy-proven HNSCC scheduled for standard-of-care surgery were enrolled in a clinical trial and underwent systemic administration of ⁸⁹Zirconium-panitumumab and panitumumab-IRDye800 followed by preoperative ⁸⁹Zr-pan PET/CT and intraoperative fluorescence imaging. The sensitivity, specificity, and AUC were evaluated.

Results:

A total of fourteen patients were enrolled and completed the study. Four patients (28.5%) had areas of high ¹⁸F-FDG uptake outside the head and neck region with maximum standardized uptake values (SUV_max) greater than 2.0 that were not detected on ⁸⁹Zr-pan PET/CT. These four patients with incidental findings underwent further workup and had no evidence of cancer on biopsy or clinical follow-up. Forty-eight lesions (primary tumor, LNs, incidental findings) with SUV_max ranging 2.0–23.6 were visualized on ¹⁸F-FDG PET/CT; 34 lesions on ⁸⁹Zr-pan PET/CT with SUV_max ranging 0.9–10.5. The combined ability of ¹⁸F-FDG PET/CT and ⁸⁹Zr-pan PET/CT to detect HNSCC in the whole body was improved with higher specificity of 96.3% [confidence interval (CI), 89.2%–100%] compared to ¹⁸F-FDG PET/CT alone with specificity of 74.1% (CI, 74.1%–90.6%). One possibly related grade 1 adverse event of prolonged QTc (460 ms) was reported but resolved in follow-up.

Conclusions:

⁸⁹Zr-pan PET/CT imaging is safe and may be valuable in discriminating incidental findings identified on ¹⁸F-FDG PET/CT from true positive lesions and in localizing metastatic LNs.