A rare-cell detector for cancer

Abstract

Although a reliable method for detection of cancer cells in blood would be an important tool for diagnosis and monitoring of solid tumors in early stages, current technologies cannot reliably detect the extremely low concentrations of these rare cells. The preferred method of detection, automated digital microscopy (ADM), is too slow to scan the large substrate areas. Here we report an approach that uses fiber-optic array scanning technology (FAST), which applies laser-printing techniques to the rare-cell detection problem. With FAST cytometry, laser-printing optics are used to excite 300,000 cells per sec, and emission is collected in an extremely wide field of view, enabling a 500-fold speed-up over ADM with comparable sensitivity and superior specificity. The combination of FAST enrichment and ADM imaging has the performance required for reliable detection of early-stage cancer in blood.

Fig. 1.

Schematic of the optical path. [Reproduced with permission from ref. (Copyright 2004, IEEE).]

Fig. 2.

Cell recovery comparison. Cell recovery of HT29 cells in peripheral blood is compared with and without immunomagnetic enrichment. The cell recovery with enrichment (□) is measured with REIS, and the cell recovery without enrichment is measured by both REIS (○) and FAST cytometry (▵). The measurements are made for two levels of expression of Ep-CAM, the target antigen for immunomagnetic enrichment.