Fig. 4.

DHART plan dose difference vs. sulphur colloid (SC) SPECT uptake for an example HCC patient. Differences in dose to the GTV-subtracted liver in the DHART plan relative to conventional RT plan are shown using both proton PBS therapy (A) and photon VMAT (B), where each data point is scaled to the absolute dose color bar. Note that dose differences were negatively rank correlated to SC SPECT uptake (R_S < −0.95, p < 0.001). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)