Introduction A salvage neck dissection (ND) after primary radio(chemo)therapy (RCT) of advanced
HNSCC should be reserved for patients with a vital residual tumor. In this regard,
the predictive power of various imaging systems has not been sufficiently clarified.
Within the scope of this study, the importance of different imaging systems 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, multicenter. Inclusion: ED HNSCC cN+; RCT, p16 status; age>
18. Exclusion: KM allergy; palliative situation after RCT; surgical capability for
ND not given; ECOG> 2; Ethics Committee LAEK RLP 2018-13274_4; DRKS 00013900. Re-staging
3 and 9-12 months after RCT respectively. 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 +.
Results From 06/18-05/20 n=40 patients were included. n=36 achieved the 1st re-staging; n=4
ND. Despite the study protocol, the IOV of the US findings showed limitations of reproducibility,
the IOV of the CT inaccuracies in the case of residuals that were difficult to define
metrically. In the PET/CT quantitative measurement of SUVmax/peak in lesions without
increased nuclide uptake and the application of the Hopkins scale proved to be difficult.
Different PET protocols and scanners limit the comparability.
Discussion The interim evaluation showed the difficulties of a standardized protocol for implementation
and evaluation, including IOV, of various imaging modalities, especially in the case
of multicenter implementation. The evaluation of the results is planned by the end
of 2021.
Poster-PDF
A-1226.pdf
DEGUM e.V.
