Combined Gadolinium and Boron Neutron Capture Therapies for Eradication of Head-and-Neck Tumor Using GdB Nanoparticles under MRI/CT Image Guidance.

Eradication of head-and-neck (H&N) tumors is very difficult and challenging because of the characteristic feature of frequent recurrence and the difficulty in killing cancer stem cells. Neutron capture therapy (NCT) is emerging as a noninvasive potential modality for treatments of various types of tumors. Herein, we report that 98.5% B-enriched anti-EGFR-GdB nanoparticles can not only deliver large doses of 158 μg B/g tumor tissues as well as 56.8 μg Gd/g tumor tissues with a very high tumor-to-blood (T/B) B ratio of 4.18, but also exert very effective CT/MRI image-guided combined GdBNCT effects on killing cancer stem cells and eradication of recurrent head-and-neck (H&N) tumors. This leads to a long average half-lifespan of 81 days for H&N tumor-bearing mice, which is a record-making result, and surpasses the best result reported in the literature using combined radiotherapy and T cell-mediated immunotherapy (70 d).