The role of volumetry in sinonasal cancer response assessment to induction chemotherapy, results from two phase II non-randomized controlled prospective multicentric trials: SINTART-1 and SINTART-2

Objective: This study aims to identify the best response criteria in patients with sinonasal cancer undergoing induction chemotherapy (IC). Material and methods: Patients enrolled in SINTART-1 and SINTART-2 were included in this study. Unidimensional diameters (anteroposterior, AP; laterolateral, LL; craniocaudal, CC), maximum axial area (Amax), and volume (V) were performed on MRI by two radiologists. RECIST 1.1 assessment was included as a categorical variable. Variables were evaluated at baseline, after the 1st chemotherapy cycle, and at the best response. Interobserver repeatability was analyzed. Stepwise univariable and multivariable Cox proportional-hazards regression models were used to correlate variables with Disease-Free Survival (DFS) and Overall Survival (OS). Results: 60 patients were included in this study. Interobserver correlation coefficient at baseline and after 1st IC cycle was excellent for V (0.916 and 0.928 respectively), CC diameter (0.96 and 0.863), and AP diameter (0.846 and 0.796), good for LL diameter, and moderate for Amax. RECIST 1.1 criteria after the 1st IC cycle and at best response were not associated with OS and DFS. Volume variation after the 1st IC cycle and at best response was significantly associated with OS (p < 0.0001 and p = 0.002) and DFS (p < 0.0001 and p = 0.005). At the multivariable analysis, V variation after the 1st IC cycle and at best response was the only variable significantly associated with OS (p < 0.001 and p = 0.0019) and DFS (p = 0.0004 and p = 0.004). Conclusions: Volume variation should be preferred to RECIST 1.1 and other measurements to describe the radiological response to IC in sinonasal cancers.