Most people would not consider swallowing a dosimeter part of a normal diet, but a new ingestible instrument provides markedly improved radiation dose measurement for those undergoing radiotherapy.

The capsule-shaped swallowable X-ray dosimeter designed by researchers from Chinese Academy of Sciences, the National University of Singapore and Tsinghua University (China) estimates radiation dose based on radioluminescence and temperature using a neural network-based regression model. This alternative to vivo dosimeters placed on a patient’s skin, such as thermoluminescence sensors, has a diameter of 5 mm and a thickness of only 0.2 mm.

The swallowable X-ray dosimeter estimates radiation dose based on radioluminescence and temperature. Source: Chinese Academy of Sciences

By internally measuring pH and temperature, the device can evaluate the absorbed dose during radiotherapy for gastric cancer and can be used to monitor treatment for different malignancies with further optimization of its size. The capsule is composed of a flexible optical fiber encapsulated with X-ray persistent nanoscintillators, a polyaniline film and a wireless miniaturized luminescence readout system.

The research published in Nature Biomedical Engineering indicates the swallowable X-ray dosimeter is approximately five times more accurate than standard methods for dose determination.