RESUMO
Objective To study the impact of implanted thermoseeds of magnetic induction hyperthermia on radiation dose distribution. Methods To simulate irradiation, an anthropomorphic phantom and three-dimensional treatment planning system were used. The impact of thermoseeds on radiation dose distribution was evaluated. Results The change of absorbed dose caused by the implantated thermoseeds was less than 1.5%. Conclusions The impact of implanted thermoseeds on radiation dose distribution is small and comes up to the requirements that the total target dose uncertainty must be less than 5%. Therefore, the impact of thermoseeds on the absorbed dose in tissue can be ignored in clinical practice.
RESUMO
Objective To examine the heating capability of thermoseeds in isolated hepatic tissues.Methods Isolated hepatic tissues were heated uniformly to 37 ℃,meanwhile the thermoseeds and thermocouples were planted using a template paralleling with the magnetic line.Afterwards,the tissues were treated in an extracorporeal magnetic field of 120-123 gauss at a frequency of 113-116 kHz for 30 minutes.At the meantime,the temperature was recorded by a computer through thermocouples. Results The temperature of the tissues raised markedly with a largest change of 14 ℃.The heating area became hard and showed a gradual change of color(white-yellow-brown).The final temperature was negatively correlated with distance when using same number of the thermoseeds(r=-0.96017 to-0.99767,P=0.0023 to 0.0398),and positively correlated with the number of thermoseeds when measuring at a same point(r=0.93775 to 0.99270,P=0.0007 to 0.0185)except for the center group(r=0.93936,P=0.0606).Conclusions Thermoseeds inductive heating technology can achieve an appropriate temperature in isolated hepatic tissues.In certain extent,the temperature increase the number of thermoseeds and heating distance.