- Results from the ACRIN 6685 trial indicate that 18F fluorodeoxyglucose (F18-FDG) positron emission tomography/CT (PET/CT) has >86% negative predictive value (NPV) for clinically N0 neck in patients with head and neck squamous cell carcinoma (HNSCC).
Why this matters
- A high NPV can help avoid unnecessary treatment.
- The NPV for clinical N0 neck sides was 0.868 (95% CI, 0.803-0.925) by visual assessment.
- At prespecified cutoffs of 2.0, 2.5, and 3.5, the NPVs specific to nodal basins of the neck region were 0.941 (95% CI, 0.930-0.953), 0.940 (95% CI, 0.928-0.952), and 0.937 (95% CI, 0.925-0.949), respectively.
- At the optimum cutoff of 1.8 (identified by receiver operating characteristic analysis), the NPV for nodal basins was 0.942 (95% CI, 0.930-0.953).
- Surgical treatment plans were changed in 51/237 evaluable patients (21.5%) based on PET/CT findings.
- In 34 patients, this led to planned dissection of additional nodal levels.
- In 6 patients, this led to planned dissection of fewer nodal levels.
- In 4 patients, this led to both additional and fewer planned dissection of nodal levels.
- In 6 patients, surgery was cancelled.
- 287 patients with HNSCC from 23 sites were included.
- Funding: National Cancer Institute.
- Lack of central pathology review of all patients.