In this pivotal TAT study on LGG that spans across a time period of 1 to 24 years (median of 10 years), incredible long-term recurrence-free survival times were observed following a local injection of [213Bi]Bi/[225Ac]Ac-DOTA-substance P. In the first case, concerning a low-grade oligodendroglioma (case 1) that exhibited the longest recurrence-free survival time, it is difficult to interpret the TAT effect due to the co-injection of the beta-labeled radiopharmaceutical [90Y]Y-DOTA-substance P, which may have enhanced the efficacy of alpha irradiation. Here, TAC1 is linked to oligodendroglioma.