Organic field-effect transistors as radiation dosimeters in medical applications

Controlling the amount of radiation that a cancer patient receives during treatment is critical to ensure the intended treatment outcome. In this work we use small molecule organic semiconductor devices as radiation sensors/dosimeters which have an effective Z close to that of human tissue. Solution processing provides excellent opportunities for scalability on flexible substrates, allowing them to conform to skin and clothing, and enabling dose measurement at the point of entry to the human body. Previous work using organic field-effect transistors (OFETs) for radiation detection has focused on radiation doses much greater than received by patients during cancer diagnostic imaging and treatment, while this work focuses on the response of OFET-based sensors at low doses relevant to cancer treatment. A systematic change in the threshold voltage of the FETs was observed with cumulative dose. Our results demonstrate that OFETs may be used in dosimetry applications for oncology.