Energy Difference Analysis Between Mri-guided Hifu And Ultrasound-guided Hifu Ablation Of Uterine Fibroids

Uterine fibroids are common benign tumor of gynecological,especially in the middle-aged women have a higher incidence. In additionto drugs, traditional surgery, uterine artery embolization, the Ultrasoundablation(UA) technology is now widely used in clinical. Its use ofwell-penetrating in the body tissue, projected high-energy focusedultrasound from external to the fibroid tumor in the body, rised thetemperature in target zone and reaches coagulation necrosis temperature (≥60℃), achieve surface non-invasive, non-invasive treatment. In theimaging system based on the scope of the lesion, target zone can beaccurately complete ablation of the lesion due to the small size of itsbiological focal region, and it will not have irreversible damage to thesurrounding normal tissue cells. In addition to the most widely usedtreatment of uterine fibroids, ultrasound ablation has also been used inosteosarcoma, liver cancer, pancreatic cancer, prostate cancer and othercancer treatments. Present study found that the efficacy of ultrasoundablation in uterine fibroids related to the properties of fibroids and the treatment parameters. Because of the treatment parameters will be affectedby properties of fibroids, so the size, location, T2WI signal values have aclose relationship with efficacy, by pre-treatment MRI (Magnetic resonanceimaging) examination can understand these properties of uterine fibroids.According to the study, T2WI signal value have a direct reflection of thehistological properties of fibroids, it can suggest differences in the smoothmuscle cells and connective tissue content which decided the effectivenessof ultrasound energy deposited in the fibroids. In addition, there areMRI-guided HIFU ablation (MRI guided HIFU, MRgHIFU) andultrasound-guided HIFU ablation (Ultrasound guided HIFU, USgHIFU)modes in clinical, with the difference between the image monitoringmethods and targets distribution methods.ObjectiveResearch two groups of patients with uterine fibroids ablation byMRgHIFU and USgHIFU, collecting MRI-T2WI signal values beforetreatment and ultrasound energy in ablation of fibroids, find out theconnection between MRI-T2WI signal values and ultrasound energy inablation of fibroids required. With a brief analysis of two ways ablation ofuterine fibroids with same T2WI signal values appear ultrasonic energydifferences. Methods1. Study subject:56cases of patients received HIFU treatment inShanghai Xuhui Central Hospital during July2009to December2013,included26cases of patients which total30fibroids in MRgHIFU group,and30cases of patients which total37fibroids in USgHIFU group.2. Equipment: MRgHIFU: Magnetom Symphony1.5T MR Tim unit(Siemens, Germany) combine of Focused Ultrasound Tumor TherapeuticSystem(developed by Chongqing Haifu (HIFU) Tech Co.Chongqing,China). USgHIFU: JC200Focused Ultrasound Tumor Therapeutic System(developed by Chongqing Haifu (HIFU) Tech Co.Chongqing, China).3. Methods3.1MRgHIFU: According to temperature changes of the target zoneand the surrounding by the monitor of magnetic resonance imaging, bygradually increasing the ultrasonic energy which raised the innertemperature of target zone to60℃and above that means to achieveablation of the target, stop treatment after ultrasonic irradiation planned tocompletely cover the entire volume from fibroids.3.2USgHIFU: Starting from the maximum level of fibroids, the targetzone is placed deep surface layer of fibroids from10mm at the rear edge,then intervals along the trailing edge of the fibroids arranged target zonearound5-8mm, after the irradiation zone coverage deep surface layer offibroids, to form the corresponding ultrasound cone field can cover theentire fibroids both the head and foot side. 4. Research and Observation indication4.1Volume ablation of rate: Using Equation: Volume ablation of rate=Non-perfused volume/Fibroids volume*100%4.2Treatment time and the Irradiation time: Treatment time is the firsttime began to ultrasonic irradiation time between the last time ultrasonicirradiation. Irradiation time refers to the projected energy ultrasoundtreatment head working hours.4.3Ultrasonic energy and ultrasonic energy per unit volume:Ultrasonic energy (KJ) is the total ultrasonic energy required in ablation,ultrasonic energy per unit volume (J/mm3) is the total ultrasonic energy perunit volume required in ablation. Using Equation: The ultrasonic energyper unit volume=Ultrasonic energy/Non-perfused volume.Results1. Properties of fibroids: The average volume of fibroids in MRgHIFUgroup and USgHIFU group is121.8±74.8cm3and114.7±53.9cm3（P>0.05）;The T2WI signal valued is121.7±38.2and135.7±44.7（P>0.05）, Therewas no statistically significant difference.2. Treatment parameters: The average ablation volume in MRgHIFUgroup and USgHIFU group is109.4±66.9cm3and101.5±50.0cm3, theablation rates is89.4±10.2%and93.9±8.7%, the EEF is4.71±3.4J/mm3and5.49±2.4J/mm3, the irradiation time is1217±397s and1309±505s, thetreatment time is132.5±37.4min and116.0±36.6min, the above data between the two groups showed no significant difference(P>0.05). Theaverage power in MRgHIFU group and USgHIFU group is302.0±53.2Wand377.8±32.2W, total energy is374.9±173.7kJ and484.6±190.6kJ, theabove data between the two groups were statistically significantdifferences.3. There is a positive linear correlation between the ultrasonic energyper unit volume and the T2WI signal valued in both group.Conclusions1. In both groups, with a higher T2signal value, higher the ultrasonicenergy per unit volume, which means the ultrasound energy required in theablation of fibroids increased.2. Due to differences between the image monitoring methods andtargets distribution methods, eventually leading to the ablation of fibroidsin the same T2WI signal value, ultrasonic energy required in USgHIFUgroup more than MRgHIFU group, but provides a higher ablation rate andfewer residual tumor tissue in USgHIFU group.