On average segmented primary tumor volumes in radiotherapy-planning CT scans were 28%% larger and largest suspect cervical LN were 13%% larger than in previous diagnostic CT scans (Table 2).
In contrast-enhanced diagnostic CT scans of 74 patients with incident advanced HNSCC, manual slice-by-slice segmentation volumetry of primary tumor, total- and largest suspect cervical LN served as the reference method.
Mean volume for largest suspect LN observed by this study was 11.0 ml.
Ellipsoid approximation resulted in an average underestimation of tumor volume by -8 % and of largest suspect LN volume by −18%%.
For the largest suspect LN, the intraclass correlation coefficient was 0.41 (95 % CI +0.17 to +0.60; p = 0.001).
Moreover, considering only the largest suspect cervical LN substantially reduces the efforts of LN-volumetry and improves readability.
Volume estimates of the largest suspect cervical LN may serve as a proxy for the total cervical metastatic burden.
Moreover, we investigated if the volume of the largest suspect cervical LN is a useful proxy for total suspect cervical LN volume.
The volumes of the largest suspect cervical LN and the sum of the volumes of all suspect cervical LN were closely correlated (r = 0.96; p = 0.001).
The largest suspect LN the mean volume was 13.8 ml (+/− 27.7 ml) with a minimum volume of 0 ml and a maximum volume of 214 ml.
