Figure 3.

Receiver operating characteristic (ROC) curves for the support vector machine classification of LR⁺RT⁺ versus LR^-RT⁺/LR^-RT^- groups within the estrogen receptor-positive (ER⁺) group (left part) and estrogen receptor-negative (ER^-) group (right part). The specificity is defined as the fraction of the LR^-RT⁺/LR^-RT^- patients correctly classified, and the sensitivity as the fraction of the LR⁺RT⁺ patients correctly classified. LR^-RT^- = no local recurrence, no radiotherapy given; LR^-RT⁺ = no local recurrence after radiotherapy; LR⁺RT⁺ = local recurrence developed after radiotherapy.