HIFU Treatment Of Adenomyosis Abdominal Fat Layer Injury Safety Evaluation And Injury Risk Prediction

Background:High intensity focused ultrasound(HIFU) through the focused ultrasound in vitro of 60-100 ℃ in the target area, so that the occurrence of coagulation necrosis, to achieve the purpose of ablation of solid tumors. HIFU in the treatment of solid tumor, ultrasound energy deposition in acoustic channel in soft tissue may cause tissue edema,induration, and even burns. According to early reports, HIFU is used for the treatment of hepatic carcinoma, the incidence of skin burns is about10%-20%. In recent years, with the accumulation of clinical experience and the improvement of HIFU technology, the risk of skin burns in HIFU treatment of hepatic carcinoma has been reduced to less than 5%. HIFU treatment of adenomyosis, skin burns risk is about 0.20%-0.45%.MRI has a high resolution of soft tissue, and sensitive in soft tissue inflammatory changes, soft tissue acute stage injury in MRI T1 WI sequence showed low or equal signal, T2 showed ill-defined, feathery flakes or high signal, with different degrees of enhancement. HIFU as a non-invasive treatment technology is widely used in the conservativetreatment of adenomyosis, occasional abdominal burns cases occur.Previous clinical trials have shown that the fat layer of the ultrasonic energy is relatively sensitive, HIFU treatment is adenomyosis layer of abdominal fat affects risk prediction research and related monitoring and evaluation of clinical HIFU treatment safety is important.Objective:Clinical manifestations and MRI signal changes evaluate HIFU treatment of uterine adenomyosis abdominal fat layer security. To investigate the correlation factors of MRI signal changes of abdominal fat layer in some patients receiving HIFU treatment, and to provide evidence for risk aversion in clinical practice.Methods:A retrospective analysis from April 2011 to October 2013 received HIFU treatment in First Affiliated Hospital of Chongqing Medical University Haifu simple hospital 97 cases of adenomyosis(25-51 years old). First, access patients MRI images of abdominal wall soft tissue records pre-HIFU and the first day post-HIFU, evaluate the ablation rate,compared to patients with abdominal fat layer signal changes in sagittal lesions maximum level. Then, according to the patient’s age(37.4 ± 5.1years old), the thickness of the abdominal wall(5 lesions the maximum level of flat waist edge, 27.60±8.74mm), the thickness of abdominal fat(5lesions the maximum level of flat waist edge, 27.60±8.74mm), treatment time 100min(range 10-300min), the total energy of treatment 378.55kJ(range 10.8-1600 k J). Treatment energy time ratio 4kJ/min(range0.07-9.12kJ/min), location(anterior 24 cases, posterior 50 cases, diffuse 23cases), uterine position(anterior 58 cases, median 6 cases and posterior 33cases), water sac volume(no bladders 15 cases, small bladders 15 cases,medium bladders 33 cases, large bladders 34 cases), the data of abdominal fat MRI signal changes(50 cases of change, 47 cases of no change).Analysis all the clinical data by SPSS 19.0 software. Use univariate analysis first, then Logistic analysis.Result:97 cases of adenomyosis patients received HIFU treatment,MRI evaluation of lesion ablation satisfaction(ablation rate of 62.16% +14.99%), the diameter of 5mm single subcutaneous induration occurred in2 cases(2.1%) post-HIFU and disappeared within 1 week, the remaining95 cases(97.9%)were not found in the fat layer of abdominal wall injury.The first post-HIFU day MRI reexamination showed 50(51.5%)patients post-HIFU of T1 WI, T2 WI, enhanced sequence fat layer signal single or all have obvious signal changes, as follows: T1 WI series of abdominal fat, 7cases of lower signal, 12 cases of slightly higher signal, 6 cases of signal disturbance, fuzzy; T2 WI sequence of abdominal fat layer, 7 cases of signal reduction, 32 cases of slightly higher signal, 8 cases of disorder and fuzzy enhance sequence of abdominal fat layer, 1 cases of edge slightly strengthened, 4 cases enhanced vessels decreased slightly.Univariate analysis showed that patients with fatty layer MRI signal change was not correlated with the clinical features of indicators include:patient age(P=0.162) and fat layer thickness(P=0.650),abdominal wall thickness(P=0.800), lesion location(P=0.418), treatment time(P=0.718),the total treatment energy(P=0.209), water sac volume(P=0.171). Logistic analysis showed no correlation with the clinical features of the patients with fat layer MRI signal changes post-HIFU including: treatment energy time ratio(P=0.014, coefficient is 0).There was a correlation between the uterine position and the changes of MRI signal in the fat layer of the patients post-HIFU(r=0.81, P=0.016), and fitted Logistic regression equation: logit(p) =- 0.648-0.579 × uterine position, Where p refers to the probability of postoperative MRI fat layer signal changes occurs,Anterior uterus means 1, the median uterus means 2, Posterior uterus means 3. Uterine position equation regression coefficient is negative, it means, post-HIFU abdominal fat layer appears MRI signal change rate:posterior uterus < the median uterus <Anterior uterus. OR=0.561, which is explained by the position of the uterus occurs abdominal fat layer MRI signal change is 56.1% before the emergence of a layer of abdominal fat MRI signal change.Conclusion:1, HIFU treatment of adenomyosis may cause abdominal fat layer damage, some patients with visual imaging(MRI signal) abnormal changes, the effect of abdominal fat layer needs a long-term observation. 2,HIFU treatment process of adenomyosis, uterine position is possible factors in patients with post-HIFU abdominal fat layer MRI signal changes, therisk anterior uterus is higher than posterior uterus. 3, HIFU treatment of adenomyosis, can assess the security of the fat layer through MRI signal changes, timely adjust the dose to avoid risks.