An optical fiber X-ray sensing array for small-field radiotherapy

The small-field radiotherapy is a developing technique because it can reduce the damage to normal tissues. However measurement of the dose distributions of small radiation fields in radiotherapy is a challenge. In this work, we designed and produced an optic fiber X-ray sensor array with high spatial resolution. The sensing array includes 7 sensing probes connecting to an 8-channel optical switch and a photon counting detector (PCD). To verify the practicality of the system, these sensors were measured under a 10x10 cm(2) field of a medical linear accelerator. For the small-field application, the dose distribution of radiotherapy fields 1x1 cm(2) and 0.8x0.8 cm(2) were measured. The distribution of these small radiotherapy fields were given based on the experimental results.