Reduction in Tumor Volume by Cone Beam Computed Tomography Predicts Overall Survival in XXXX Treated With Chemoradiation Therapy.

@entity5 @entity1 @entity1149 @entity204
PURPOSE: We sought to evaluate whether @entity5 response using cone beam computed tomography (CBCT) performed as part of the routine care during chemoradiation therapy (CRT) could forecast the outcome of unresectable, locally advanced, @entity1149 ( @entity1149 ). METHODS AND MATERIALS: We manually delineated primary @entity5 volumes (TV) of @entity1 with @entity1149 who were treated with radical CRT on days 1, 8, 15, 22, 29, 36, and 43 on CBCTs obtained as part of the standard radiation treatment course. Percentage reductions in TV were calculated and then correlated to survival and pattern of recurrence using Cox proportional hazard models. Clinical information including histologic subtype was also considered in the study of such associations. RESULTS: We evaluated 38 @entity1 with a median follow-up time of 23.4  months. The median TV reduction was 39.3% (range, 7.3%-69.3%) from day 1 (D1) to day 43 (D43) CBCTs. Overall survival was associated with TV reduction from D1 to D43 (hazard ratio [HR] 0.557, 95% CI 0.39-0.79, P=.0009). For every 10% decrease in TV from D1 to D43, the risk of @entity204 decreased by 44.3%. For @entity1 whose TV decreased >= 39.3 or <39.3%, log-rank test demonstrated a separation in survival (P=.02), with median survivals of 31  months versus 10  months, respectively. Neither local recurrence (HR 0.791, 95% CI 0.51-1.23, P=.29), nor distant recurrence (HR 0.78, 95% CI 0.57-1.08, P=.137) correlated with TV decrease from D1 to D43. Histologic subtype showed no impact on our findings. CONCLUSIONS: TV reduction as determined by CBCT during CRT as part of routine care predicts post-CRT survival. Such knowledge may justify intensification of RT or application of additional therapies. Assessment of genomic characteristics of these @entity5 may permit a better understanding of behavior or prediction of therapeutic outcomes.
