FIGURE 3.
(A) Implementation of MSI matrix, which summarizes cooccurrence statistics among different habitat regions and is computed separately for pre- and midtreatment image. ∆MSI (MSImidtreatment − MSIpretreatment) is calculated to quantify change of spatial habitat interaction. (B) Implementation of spatiotemporal habitat evolution matrix to summarize temporal cooccurrence statistics among spatially coregistered habitat maps, where voxel-level evolution of habitats from baseline to midtreatment is characterized. In both cases, we explicitly included surrounding tissue as distinct habitat region to account for its relationship with tumor. pre-RT = pretreatment of radiation therapy; mid-RT = midtreatment of radiation therapy.