Massachusetts General Hospital researchers have build a device that can detect and capture minute numbers of tumor cells circulating in the blood of lung cancer patients and find genetic characteristics of the cells that could determine the best treatment options.

The research may one day make monitoring the disease as simple as taking a blood test, without invasive procedures to get samples. Lung tumor biopsies are particularly difficult to obtain, and even a technique in which a fine needle is inserted into the tumor and used to draw off a tiny number of cells comes with risks.

Circulating tumor cells (CTCs) are living solid-tumor cells found at extremely low levels in the bloodstream, which they can enter during even the earliest stages of cancer. Until the development of the MGH device, it was not possible to get information from CTCs that would be useful for clinical decision-making.