Comparison of imaging for cervical lymph nodes after primary radio(chemo)therapy of advanced HNSCC – preliminary findings of the HN-Onkoimage-1 trial

Introduction A salvage neck dissection (ND) after primary radio(chemo)therapy (RCT) for advanced HNSCC should be reserved for patients with a vital residual tumor. In the course of this study, the relevance of imaging for re-staging 3 months after RCT is to be examined further. The results of the interobserver validation (IOV) are described in relation to problems of the study implementation and evaluation.

Material and Method Design: prospective, multicentric. Inclusion: ED HNSCC cN+; RCT, p16 for OPSCC, age> 18. Exclusion: KM allergy; palliative situation after RCT, patient not suitable for ND, ECOG> 2; Ethics Committee LAEK RLP 2018-13274_4; DRKS 00013900. Endpoints: Sens, Spec, PPW, NPW and misclassification rate, as well as pairwise comparisons of US, CT, PET/CT in the assessment of N0 vs. N+. The comparison of the diagnosed yN status is made with the result of the ND for ycN+ and for the 2nd re-staging after further 6-9 months for ycN0

Results From 06/18-05/20 n=40 patients were included (Mainz 18, Homburg 11, Regensburg 11). N = 36 achieved the 1st re-staging; N=4 ND. IOV US: Findings partly not clearly reproducible. IOV CT: Re-staging partly uncertain with residual metrically difficult to detect. IOV PET / CT: Quantitative measurement of SUVmax/SUVpeak without increased nuclide uptake difficult. Direct comparison of the uptake in the target with SUVmean of the liver/blood pool is not possible if separate torso and head/neck sequence (Hopkins scale is limited). Different PET protocols and scanners limit the comparability.

Discussion The initial study goal of n=100 was abandoned because only a few patients had the indication for ND. Further limitations resulted from the IOV. Descriptive evaluation of the results is planned by the end of 2022.

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Artikel online veröffentlicht:
20. Juni 2022