Diagnostic performance of FDG PET/MRI for cervical lymph node metastasis in patients with clinically N0 head and neck cancer.

Objective: Treatment management in cases of head and neck squamous cell cancer (HNSCC) that are clinically negative for lymph node metastases (cN0) is still an important topic of discussion. There is increasing interest in sensitive imaging modalities that can detect the risk of occult metastases at levels below 20%. This study aimed to examine the efficacy of integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) in determining neck nodal metastasis status in cN0 patients with HNSCC.

Patients And Methods: In this retrospective study, 44 patients who underwent neck dissection with the diagnosis of HNSCC between January 2018 and August 2020 were analyzed. Clinical examinations, including ultrasonography, were performed to identify cervical metastases in HNSCC patients with preoperative cN0. A nuclear medicine specialist visually evaluated the MRI, PET, and PET/MRI results.

Results: Histopathologically, 86.4% of patients were classified as N0. According to the histopathological results, MRI showed 50% sensitivity, 89.5% specificity, 91.8% negative predictive value (NPV), 42.8% positive predictive value (PPV) and 84% accuracy, while PET showed 83.3% sensitivity, 68.4% specificity, 96.2% NPV, 29.4% PPV and 70.4% accuracy. PET/MRI was more successful in distinguishing pathological N0 and N+ patients (83.3% sensitivity, 92.1% specificity, 97.2% NPV, 62.5% PPV and 90.9% accuracy).

Conclusions: PET/MRI is more sensitive and has a higher NPV compared to MRI alone, while its sensitivity was found to be comparable to that of PET. In addition, with its ability to detect pathological N0 patients, PET/MRI may significantly decrease the number of unnecessary neck dissections.