I-BFM-SG treatment protocol and RFS of T-ALL and precursor B-ALL.

(A) Hypothetical graph shows the kinetics of leukemic cell decrease and regrowth in several ALL patients during and after treatment with the I-BFM-SG treatment protocol. MRD curves represent individual patients of the 3 MRD-based risk groups27—2 patients with slow MRD clearance and in the high-risk group; 2 patients with moderate MRD clearance and in the intermediate-risk group; and one patient with rapid MRD clearance in the low-risk group. The detection limit of cytomorphologic techniques and the detection-limit range of the PCR technique are indicated. Vertical arrows represent BM sampling time points at diagnosis, before each treatment block, at several time points during maintenance treatment, at cessation of therapy, and 1 year thereafter. I indicates induction treatment; C, consolidation treatment; II, reinduction treatment. (B) RFS of the 71 T-ALL and the 210 precursor B-ALL patients. Tick marks indicate censored survival times.