A trend towards increases in SUVpeak TBR, which highlights hotspots of CD8+ cells within the tumor region, was seen in nonresponders (5.23 ± 1.77) when compared to responders (4.15 ± 0.78) but did not reach significance (p > 0.05), Figure 4D. In addition, evaluation for the heterogeneity of CD8 signal distribution as measured by number of regional peaks over tumor region, see Figure S3, showed significantly decreased heterogeneity in immunotherapy responders (0.88 ± 0.15, p < 0.05) when compared to immunotherapy non-responders (0.99 ± 0.06), see Figure 4E and Table S2. Here, CD8A is linked to neoplasm.