spinal accessory nodes (IIb), or submental-submandibular nodes (Ia and Ib) or showing a lack of central lymph node necrosis in nodes of any size. Participants all received a presurgical FDG-PET/CT scan to which the surgeon was blinded and a contrast-enhanced MRI or CT scan of the neck (all within 4 weeks of surgery). The surgical plans were devised by the local surgeons on the basis of physical examination and CT and/or MRI results, but not PET/CT (pre-PET/CT surgical plan) and thereafter formulated with the PET/CT result (post-PET/CT surgical plan), and both plans were collected prospectively with questionnaires. All participants provided written informed consent and all sites received approval for participation from their local investigational review boards. All data were anonymized to protect the identities of the participants. Study Overview: Participants with newly diagnosed head and neck SCC will underwent a FDG-PET/CT scan prior to surgical resection. The surgeon had access to the PET/CT results prior to the surgical procedure. The study collected data on how the inclusion of the PET/CT results impact the determination of extent of disease, disease characterization and prognosis, and the surgical plan originally devised from clinical nodal assessment and CT and/or MRI results. Participants all received a presurgical FDG-PET/CT scan to which the surgeon was blinded and a contrast-enhanced MRI or CT scan of the neck (all within 4 weeks of surgery). The surgical plans were devised by the local surgeons on the basis of physical examination and CT and/or MRI results, but not PET/CT (pre-PET/CT surgical plan) and thereafter formulated with the PET/CT result (post-PET/CT surgical plan), and both plans were collected prospectively with questionnaires. Imaging Protocol:Imaging with FDG-PET/CT was performed with a dedicated head and neck (H&N) PET/CT using two bed positions from the orbits to the upper thorax (top of aortic arch) with arms down and with images acquisitions at 6 minutes per bed position. Of the 248 eligible participants, 54 underwent H&N scans only, 30 underwent whole-body (WB) scans only, and six underwent neither. Imaging from the orbits or chest through the upper thighs was also obtained. See the Data Supplement for detailed methods of imaging, image analysis, surgery methods, and pathology methods. Results:PET/CT scans and pathology findings were available for 270 N0 neck sides from 212 participants. For visual assessment, the NPV specific to the clinical-N0 sides was 0.868 (95% CI, 0.803 to 0.925). For dichotomized maximum standardized uptake value, the NPVs specific to the nodal basins were 0.940 (95% CI, 0.928 to 0.952) and 0.937 (95% CI, 0.925 to 0.949) at prespecified cutoffs of 2.5 and 3.5, respectively. The optimal cutoff maximum standardized uptake value was determined to be 1.8, with an NPV of 0.942 (95% CI, 0.930 to 0.953). The PET/CT-informed surgical treatment plan was changed in 51 of 237 participants (22%) compared with the PET/CT-blinded surgical plan. In 34 participants (14%), this led to planned dissection of additional nodal levels. In 12 participants (5%), this led to fewer planned dissected nodal levels. Negative PET/CT scans in N0 necks was true negative in 87% and false negative in 13%. Conclusion:PET/CT has a high NPV for N0 HNSCC. SUV analysis is superior to visual assessment with regard to NPV. There is a high degree of reader agreement for PET/CT of the patient with an N0 neck. These findings suggest that FDG-PET/CT may assist the clinician in deciding on the best therapy for the clinically N0 neck in HNSCC. Date Offsets: |