From dimensions through dynamics to outcomes - lymph nodes and skin assessments predict CTCL outcomes

Radiologic nodal staging in CTCL traditionally uses a 1.5 cm longest diameter (LDi) cutoff; however, this lacks validation and may misclassify risk. We conducted a retrospective analysis of 6,095 CT scans from 262 CTCL patients in the MAVORIC trial using unidimensional, bidimensional, and volumetric LN measurements and mSWAT scores. Optimal cutoffs were determined via ROC analysis and landmarking adjusted for informative censoring. Additionally, kinetic modeling growth rates (g) were calculated for both LN and skin scores. We demonstrated that LDi > 1.5 cm did not predict OS (p = 0.8). However, baseline volumetric cutoffs (3,945 mm³; AUC = 0.67) stratified OS (median 43.6 months vs NA, log-rank p = 0.035); post‑landmark analysis (6,930 mm³) enhanced discrimination. High g (volumetric or mSWAT) independently predicted shorter OS/PFS/TTF (p < 0.05). A combined model (volume + g) had C‑index 0.63 versus 0.60 for volume alone. We conclude that volumetric and dynamic metrics outperform conventional measures in predicting CTCL outcomes. Incorporating these methods into staging and trial criteria is warranted.