SU-E-J-236: Feasibility of Using Infrared Imaging to Verify the Accuracy of the Radiotherapy Delivery




To assess whether infrared imaging can be used to verify the accuracy of the radiation treatment delivery.


Radiation treatment induced skin reactions include acute changes (erythema and pigmentation) and chronic changes (telangiectasia and ulceration). Thermal imaging can detect these reactions before they become visible. A thermal camera with infrared spectral band 7.5 μm to 14 μm, and temperature measurement range from −20 °C to +150 °C and accuracy of ±2 °C was used. Beams-eye-view images were taken by the end of each treatment for a head and neck patient. The temperature changes of three points were monitored throughout the treatment course, including two points in the field (canthus and vessel) and one point outside of the field. The thermal images were warped and registered to the corresponding planning CT skin rendering. Dose map was exported from the treatment planning system and warped and registered to the planning CT skin rendering as well. The correlation between these two warped and registered images was calculated. The time spent to take the images was recorded.


The temperatures of the two points inside the field were always higher than the temperature of the point outside of the field. The temperature inside the field tended to increase as more fractions delivered to the patient. A correlation of 0.90 was found between the registered thermal image and the 3D dose map. On average, half minute was needed to take the images after each treatment.


Thermal imaging can monitor the temperature variations of the skin, and the temperatures were proportional to the dose map. It can therefore potentially be an inexpensive and non-ionization tool to verify the accuracy of the radiation treatment delivery.