Lens Exposure During Percutaneous Trigeminal Nerve Radiofrequency Rhizotomy Guided by Computed Tomography with Three-Dimensional Image Reconstruction
M Yeh*, Y Tsai, H Liu, J Yang, H Weng, Chang Gung Memorial Hospital, ChiayiChiayi CountySU-E-J-58 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
The eye lens is one of the most radiosensitive tissues; it is an issue to estimate the lens dose during the percutaneous trigeminal nerve radiofrequency rhizotomy guided by computed tomography. The purpose of this abstract was to prove the CTDI(computed tomography dose index) peripheral (CTDIp) could be provided a reference value for the eye lens dose.
There are two methods for estimate the eye lens dose in this study. The first is CTDIp calculated and second is ImPACT software which is common used in CT dose calculation. We Collected the CTDIv in dose report which create from CT scanner automatically. Ten patients who performed the trigeminal neuralgia underwent computed tomography (CT)-guided percutaneous radiofrequency trigeminal rhizotomy was included. In order to find out the factor of CTDIv and CTDIp, we measured the CTDIv and CTDIp using ion-chamber and 16-cm diameter CTDI dose phantom. On the other hand, we also apply the ImPACT software to estimate the eye lens dose, and compare the two values, CTDIp and the eye lens dose from ImPACT.
The factor of CTDIv to CTDIp is 1.02. The average CTDIp in 10 patients is 116.65 mGy, and the average lens dose from ImPACT is 124 mGy. It is only 6% error.
CTDIp can be provided a reference value for the eye lens dose. And the CTDIv can display in modern CT scanner in time, the radiologist can monitor the radiation dose during the exam. However,how to reduce the lens dose in this process would be next important issue foe us.