The usefulness of combining narrow-band imaging with magnifying endoscopy and 18F-fluorodeoxyglucose positron emission tomography for predicting the depth of invasion in superficial esophageal squamous cell carcinoma.

BACKGROUND

To ascertain the indication of endoscopic resection (ER) for esophageal squamous cell carcinoma (ESCC), accurate preoperative diagnosis of the tumor depth beyond cT1b-SM2 is crucial. This study aimed to assess the efficacy of the combined approach utilizing narrow-band imaging with magnifying endoscopy (NBI-ME) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for accurate discrimination of lesions of pT1b-SM2 or deeper.

METHODS

Between 2016 and 2023, we retrospectively enrolled 127 cases (137 lesions) of superficial, treatment-naïve ESCC at Akita University Hospital, involving patients who underwent either ER alone or surgery alone. All patients underwent preoperative NBI-ME and FDG-PET. Preoperative tumor depth was estimated using type B vessels based on NBI-ME and SUVmax based on FDG-PET, and we confirmed the final tumor depth through histopathological evaluation of resected samples. The diagnostic performance of the tests in discriminating pT1b-SM2 or deeper was evaluated in terms of sensitivity, specificity, and accuracy.

RESULTS

Treatment consisted of ER in 97 lesions and surgery in the remaining 40. Fifty-three lesions (44.7%) had pT1b-SM2 or deeper invasion. The sensitivity, specificity, and accuracy of NBI-ME using type B3 vessels were 41.5%, 97.6%, and 75.9%, respectively. For FDG-PET with a cutoff SUVmax of ≥ 2.4, these were 79.2%, 69.0%, and 73.0%, respectively. Combining both tests substantially improved diagnostic performance, with sensitivity, specificity, and accuracy of 83.0%, 89.3%, and 86.9%, respectively.

CONCLUSION

The combination of FDG-PET and NBI-ME offers enhanced diagnostic performance for ESCC with ≥ pT1b-SM2, thereby facilitating a more efficacious preoperative narrowing of the indications for ER of superficial ESCC.