18F FDG PET/CT Prediction of Treatment Outcomes in HPV-positive, Locally Advanced Oropharyngeal Cancer Receiving De-intensified Therapy: Results from NRG-HN002. Journal of nuclear medicine : official publication, Society of Nuclear Medicine Subramaniam, R. M., DeMora, L., Yao, M., Yom, S. S., Gillison, M., Caudell, J. J., Waldron, J., Xia, P., Chung, C., Truong, M. T., Echevarria, M., Chan, J. W., Geiger, J. L., Mell, L., Seaward, S., Thorstad, W. L., Beitler, J. J., Sultanem, K., Blakaj, D., Le, Q. 2022


Objective: To determine the negative predictive value (NPV) of a 12-14 week post-treatment PET/CT for 2-year progression-free survival (PFS) and locoregional control (LRC) in patients with p16-positive locoregionally advanced oropharyngeal cancer (LA-OPC). Study was a secondary endpoint in NRG-HN002, a non-comparative phase II trial in p16-positive LA-OPC, stage T1-T2, N1-N2b or T3, N0-N2b (AJCC, 7th ed.) and = 10 pack-year smoking. Patients were randomized in a 1:1 ratio to reduced-dose IMRT with or without cisplatin. Methods: PET/CT scans were reviewed centrally. Tumor response evaluations for the primary site, right neck, and left neck were carried out using a 5-point ordinal scale (Hopkins Criteria). Overall scores were then assigned as 'Negative,' Positive,' or 'Indeterminate'. Patients with a 'Negative' score for all three evaluation sites were given an overall score of 'Negative.' The hypotheses were NPV for PFS and LRC at two years post-treatment = 90% vs >90% (1-sided alpha 0.10). Results: There were 316 patients enrolled, of whom 306 were randomized and eligible. Of these, 131 (42.8%) patients consented to a post-therapy PET/CT, and 117 (89.3%) patients were eligible for PET/CT analysis. The median time from the end of treatment to PET/CT scan was 94 days (range 52-139). Estimated 2-year PFS and LRC rates in the analysis subgroup were 91.3% (95% confidence interval CI [84.6, 95.8%]) and 93.8% (95% CI [87.6, 97.5%]), respectively. Post-treatment scans were negative for residual tumor for 115 patients (98.3%) and positive for two patients (1.7%). NPV for 2-year PFS was 92.0% (90% lower confidence bound [LCB] 87.7%; P = 0.30) and for LRC was 94.5% (90% LCB 90.6%; P = 0.07). Conclusion: In the context of deintensification with reduced-dose radiation, the NPV of a 12-14 week post-therapy PET/CT for 2-year LRC is estimated to be > 90%, similar to that reported for patients receiving standard chemoradiation. However, there is insufficient evidence to conclude that the NPV is > 90% for PFS.

View details for DOI 10.2967/jnumed.122.264424

View details for PubMedID 36215572