IART: intraoperative avidination for radionuclide treatment. A new way of partial breast irradiation.

A new procedure, known as Intraoperative Avidination for Radionuclide Therapy (IART), is described in breast cancer patients. In this paper, we provide proof of the principle that intraoperative injection of avidin in the tumour bed after quadrantectomy allows homing in of intravenously (IV) administered radioactive biotin to the target site. This approach of targeted therapy consists of two steps: (i) "avidination" of the anatomical area of the tumour with avidin injected by the surgeon, into and around the tumour bed; (ii) targeting the anatomical area of the tumour by IV injection of radiolabelled biotin. The scintigraphic images demonstrated fast and stable uptake of labelled biotin at the site of operated breast. The radiation dose released to the index quadrant was more than 5 Gy/GBq, consistent with a boost of 20 Gy for an activity of 3.7 GBq 90Y-biotin (100mCi). A further large clinical trial facing IART in combination with reduced external-beam radiotherapy is, in our opinion, fully justified.