Prog Med Phys.  2020 Sep;31(S1):S67.

Prediction of Tumor Temperature in Regional Hyperthermia by Using LED Luminance

• Lee J
• Hwang J
• Seol Y
• Oh T
• An Ny
• Han K
• Jang HS
• Choi BO
• Kang Yn

Abstract

Introduction
Hyperthermia is used to destroy tumors by generating heat in the body (40-45°C). In particular, regional hyperthermia entails intense heating of tumors rather than raising the temperature of the body. In regional hyperthermia, the prediction of the tumor temperature before treatment is essential to ensure treatment efficiency and patient safety. The goal of this study is to predict the temperature of tumors in regional hyperthermia by using a light emitting diode (LED). Materials & Methods: The experiment was conducted using REMISSION 1 °C (AdipoLabs, Republic of Korea), hyperthermia with a frequency of 0.46 MHz, at 120 Watt. Luminance meter (HD2102.1, DELTA OHM, Italy) was used to quantitatively check the brightness distribution of LED. Temperature distribution was measured by a thermometer (OPTOCON, Weidmann, Germany) at the same point where each LED was located. Voltage was measured by a oscilloscope (TDS3032, Tektronix, USA) The composition of phantom consists of 4.8L of water, NaCl 17.28 g and Agar powder 105.8g
Results
The temperatures measured directly and via simulation were compared to the temperature measured in order to verify the method of temperature prediction based on LED luminance. The error between the measured and the simulated temperature (M&S), the measured and the predicted temperature via luminance (M&P), and the simulated and the predicted temperature based on luminance (S&P) were compared. The error within the electrode size range was within 3%.
Conclusions
In this study, the temperature predicted by using the LED luminance, the temperature measured using a multichannel optical fiber thermometer, and the temperature obtained using the commercially available simulation program (Sim4life) were compared. The voltage was determined via the luminance. The SAR was predicted by using the acquired voltage. In the end, we confirmed that temperature prediction was possible using luminance. Through the use of LED phantom to determine the SAR distribution of the resistive electric transfer in hyperthermia, QA of the equipment ensures the safety of treatment.