Quantum cascade laser thermal therapy guided by FDOCT

We demonstrate Fourier domain optical coherenc tomography （FDOCT） monitoring and guiding of quantum cascade laser （QCL） therapy. The laser therapy is performed with a 6.1-tim mid-IR QCL and it involves both tissue coagulation or ablation. FDOCT allows real-time monitoring that minimize unnecessary damage to the surrounding tissues. We perform lipid phantom tissue ablation, chicken egg yolk coagulation, and tissue and blood vessel coagulation on chicken embryo to validate the FDOCT guiding quantum cascade laser therapy.

Advanced Treatment Planning in Cancer Thermal Therapies

CEM43 thermal dose is a very common concept in thermal oncology.Thermal dose is the maximum amount of energy that can be transmitted during hyperthermia therapy conducted on temperature-sensitive tissue.Thermal dose is also the maximum value of local energy accumulation in human bodies,which can lead to tissue injury and pain.Thermal dose can also decrease the finishing temperature and reduce the energy to the tolerable range.There are two functions of the individualized hyperthermia treatment plan:it determines the setting and location that can realize the best tumor hyperthermia therapy;at the same time,it can decrease the effect of hyperthermia therapy on healthy tissues.There are four steps in the treatment plan of hyperthermia therapy for tumors:the first step is to establish a three dimensional human body model and its corresponding an atomical structure that can be used in numerical algorithm via medical imaging resources;the second step is to determine the volume of the electromagnetic energy accumulation.Based on the peculiarity of frequency and materials,even full-wave electromagnetic wave or quasi-static technique can be used to determine the tissue distribution.Evaluation of the therapy can be conducted based on thermal dose and the corresponding tissue damage model;the third step is to use Arrhenius model to provide direct evaluation of tissues in the thermal ablation zone,solidification zone,as well as the necrotic area;the last step is the optimization of the treatment plan.

Mn-doped Ti-based MOFs for magnetic resonance imaging-guided synergistic microwave thermal and microwave dynamic therapy of liver cancer

Currently,precise ablation of tumors without damaging the surrounding normal tissue is still an urgent problem for clinical microwave therapy of liver cancer.Herein,we synthesized Mn-doped Ti MOFs(Mn-Ti MOFs)nanosheets by in-situ doping method and applied them for microwave therapy.Infrared thermal imaging results indicate Mn-Ti MOFs can rapidly increase the temperature of normal saline,attributing to the porous structure improving microwave-induced ion collision frequency.Moreover,Mn-Ti MOFs show higher 1O2 output than Ti MOFs under 2 W of low-power microwave irradiation due to the narrower band-gap after Mn doping.At the same time,Mn endows the MOFs with a desirable T1 contrast of magnetic resonance imaging(r2/r1=2.315).Further,results on HepG2 tumor-bearing mice prove that microwave-triggered Mn-Ti MOFs nearly eradicate the tumors after 14 days of treatment.Our study offers a promising sensitizer for synergistic microwave thermal and microwave dynamic therapy of liver cancer.

Temperature imaging with speed of ultrasonic transmission tomography for medical treatment control:A physical model-based method

Hyperthermia is a promising method to enhance chemo and radiation therapy of breast cancer. In the process of hyperthermia, temperature monitoring is of great importance to assure the effectiveness of treatment. The transmission speed of ultrasound in biomedical tissue changes with temperature. However, when mapping the speed of sound directly to temperature in each pixel as desired for using all speeds of ultrasound data, temperature bipolar edge enhancement artifacts occur near the boundary of two tissues with different speeds of ultrasound. After the analysis of the reasons for causing these artifacts, an optimized method is introduced to rebuild the temperature field image by using the continuity constraint as the judgment criterion. The significant smoothness of the rebuilding image in the transitional area shows that our proposed method can build a more precise temperature image for controlling the medical thermal treatment.

A low-cost invasive microwave ablation antenna with a directional heating pattern

Microwave ablation(MWA) is a cancer treatment method. The tumor tissue absorbs electromagnetic energy, which heats and kills it. A microwave ablation antenna plays a critical role in this process. Its radiation field must completely cover the tumor but not the healthy tissue. At present, the radiation pattern of most invasive ablation antennas is spherical.However, in the clinic, the shape of some tumors may be asymmetrical or the antenna cannot be inserted into the center of the tumor for some other reason. In order to solve these problems, a directional heating antenna for microwave ablation is proposed in this paper. The proposed antenna, operating at 2.45 GHz, consists of a monopole and a reflector. The feed is given by a substrate integrated coaxial line(SICL) and coplanar waveguide(CPW). The omnidirectional radiation field of the monopole is reflected by a reflector that is extended from the outer conductors of the SICL to form a directional radiation field. The impedance matching network is designed on SICL to match the antenna to 50 Ω. The antenna is fabricated using a mature printed circuit board(PCB). The reflection coefficient of the antenna in porcine liver tissue measured by a vector network analyzer shows good agreement with the simulations. Then, an ablation experiment in porcine liver is conducted with power of 10 W for 10 min, and the experimental results confirm the validity of the design.