Study On Mechanisms For A Highly Efficient Freezing/Heating Physical Treatment Of Tumor

There currently exists an urgent problem to extend the conventional cryosurgical therapy to the maximum extent and break through the bottleneck of freezing/heating treatment. With the successful development of new-generation surgical instrument, the Freezing/Heating hybrid treatment instrument (FHHTI), and introduction of nanotechnology, infrared thermal imaging method etc., the conventional cryosurgery is expected to be significantly innovated. This thesis is dedicated to investigate the mechanisms thus involved from both theoretical and experimental approaches. Progresses achieved were as follows:1. The working performance of the new-generation FHHTI was experimentally investigated, in which the features of the device were demonstrated and the advantages of FHHTI were compared with conventional cryosurgical instruments. The obtained results are expected to be of valuable reference in clinics.2. A new treatment modality, named as one time's percutaneous insertion while multiple times'freezing/heating cycles, to significantly maximize cryosurgical killing scope while minimize the invasive mechanical trauma was originally proposed. The method was successfully applied to treat irregularly shaped tumors and is useful for the conformal treatment of solid tumors.3. A novel surgical strategy, termed as nano-cryosurgery was proposed for the first time. Theoretical models from micro to macro scale were established for the mechanism interpretation. Several conceptual experiments were also performed to testify the feasibility and efficiency of this novel combined therapy.4. A method using highly safe hybrid cryosurgical/hyperthermia probe via an adiabatic thin layer material was proposed. Both theoretical analysis and experimental results demonstrate the feasibility of the method, which provides a valuable strategy to perform a safe and efficient freezing and heating treatment on tumor in the near future.5. The infrared thermography (IRT) was originally suggested as an auxiliary imaging tool for the evaluation and administration of a cryosurgery. Both typical animal and clinical tests were performed to evaluate the feasibility and advantages of IRT guided cryosurgery.6. A generalized entropy generation theory was originally proposed to quantify the freezing/heating damage and treat efficiency of the cryosurgery. Comprehensive entropy generation analysis was performed on several important issues about cryoinjury during freezing process. This study may possibly open a new theoretical strategy for evaluating the final output of either cryobiology or hyperthermia practices from micro to macro scales.