Figure 2. Comparison of principal components derived from Raman spectra of non-small cell lung cancer irradiated in vitro and in vivo.

Principal component (PC) 1 (a) and PC2 (b) obtained for the current ex vivo study (black line) overlayed with the corresponding component obtained in a previous in vitro study on the H460 cell line. In vitro data was derived from principal component analysis on a Raman data set of H460 cells cultured an irradiated in vitro to doses of 0, 2, 4, 6, 8, 10, 30 and 50 Gy as presented and described previously¹⁹. Principal component 1 from this ex vivo study is highly correlated (Pearson’s r value = 0.95) to PC1 from the in vitro experiment, as is PC2 (Pearson’s r value = 0.85).