Image-guided thermal therapy of uterine fibroids

Differentiating leiomyosarcoma from leiomyoma: in support of an MR imaging predictive scoring system

PURPOSE

The purpose of this study was to determine the Magnetic Resonance (MR) imaging features that best differentiate leiomyosarcoma (LMS) from leiomyoma, and to explore a scoring system to preoperatively identify those at highest risk of having LMS.

METHODS

Our Institutional Review Board approved this retrospective HIPAA-compliant study with a waiver for written informed consent. Institutional Research Patient Data Registry identified patients with histopathologically-proven LMS (n = 19) or leiomyoma (n = 25) and a pelvic MRI within six months prior to surgery. Qualitative differentiating MRI features were selected based on prior publications and clinical experience. Patient and MRI characteristics for leiomyomas versus LMS were compared using Wilcoxon rank-sum tests or Fisher's exact tests and using a basic classification tree. Hypothesis testing was two-tailed, with a p value < 0.001 used to determine inclusion of variables into an MR imaging predictive (MRP) score. Diagnostic performance [sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV)] of the MRP in diagnosis of LMS used all possible scores as cutoffs.

RESULTS

Seven out of 15 MRI features were found to have an association with LMS. The final MRP scores ranged from 0 to 7: a score of 0-3 was associated with 100% NPV for LMS, and a MRP score of 6-7 with 100% PPV for LMS.

CONCLUSION

Seven qualitative MR imaging features, extracted from a standard MR imaging protocol, allow differentiation of LMS from leiomyoma. An exploratory risk stratification MRP score can be used to determine the likelihood of LMS being present.

Magnetic Resonance Imaging in the Evaluation of Female Infertility

Pelvic MRI plays an important adjunctive role in the clinical workup of female infertility. Hysterosalpingography is the first line imaging modality in evaluation of female infertility, and hysterosalpingo-contrast sonography can also be used to evaluate both the uterine cavity and fallopian tubes. Pelvic MRI can be helpful in the workup of female infertility, particularly in cases of Mullerian duct anomalies, fibroids, adenomyosis, endometriosis, and tubal disease. These conditions and their appearance on imaging will be reviewed in this article.

Laparoscopic In-Bag Morcellation Compared with Conventional Morcellation of Myomas and Uterus with Myomas

STUDY OBJECTIVE

To evaluate contained bag electromechanical morcellation for removal of myomas and uterus with myomas, laparoscopically (Study group B), and compare it with uncontained laparoscopic morcellation (Control group A) in patients with similar parameters done earlier.

DESIGN

Retrospective Cohort Comparative Study (Canadian Task Force 2-1).

SETTING

Advanced Gynaecologic MAS, university recognized tertiary centre, Mumbai, India.

PATIENTS

720 women had laparoscopic removal of myomas or large uterus with myomas during a study period of 6 years (from 13 May 2012 to 14 August 2018) with contained bag electromechanical or conventional morcellation.

INTERVENTIONS

Laparoscopic hysterectomy, laparoscopic myomectomy, conventional uncontained morcellation, contained in-bag morcellation.

MAIN OUTCOMES MEASURES

Laparoscopic contained in-bag morcellation was compared with conventional morcellation of myomas and uterus with large myomas during a study period of 6 years. Parameters assessed were operating time, time for insertion of bag, morcellation of tissues and removal of bag, blood loss, complications, conversion to open surgery and histopathologic findings of tissues. In Group A, in the first 3 years, 355 women underwent uncontained morcellation. Myoma size and weight varied from 5 cm to 26 cm and 200 g to 3740 g respectively. The myoma number ranged from 1 to 18. No case of leiomyosarcoma was reported. In Group B, in the next 3 years, 365 women underwent contained bag morcellation in 196 myomectomy cases and 169 hysterectomy cases. Myoma size and weight varied from 4 cm to 20 cm and 200 g to 2100 g respectively. The number of myomas varied from 1 to 17.

RESULTS AND CONCLUSION

Laparoscopic contained bag morcellation for myomas and uterus with large myomas were evaluated. In myomectomy group both conventional and in bag laparoscopic morcellation were comparable in terms of duration of the surgery and blood loss. When all cases ( hysterectomy and myomectomy combined together) and cases of hysterectomy with large fibroid were studied, laparoscopic in bag morcellation took less operative time and there was statistically significant difference in operative time . No case of leiomyosarcoma was found in our study of 720 cases of myomas or uterus with large myomas.

A tissue preparation to characterize uterine fibroid tissue properties for thermal therapies

PURPOSE

Treating uterine fibroids with less invasive therapies such as magnetic resonance-guided focused ultrasound (MRgFUS) is an attractive alternative to surgery. Treatment planning can improve MRgFUS procedures and reduce treatment times, but the tissue properties that currently inform treatment planning tools are not adequate. This study aims to develop an ex vivo uterine fibroid model that can emulate the in vivo environment allowing for characterization of the uterus and fibroid MR, acoustic, and thermal tissue properties while maintaining viability for the necessary postsurgical histopathological assessments.

METHODS

Women undergoing a hysterectomy due to fibroid-related symptoms were invited to undergo a preoperative pelvic MRI and to permit postoperative testing of their uterine specimen. Patients that declined or could not be scheduled for a pre-operative MRI were still able to allow post-operative testing of their excised tissue. Following surgical removal of the uterus, nonmorcellated tissues were reperfused with a Krebs-Henseleit buffer solution. An MR-compatible perfusion system was designed to maintain tissue viability inside the MR suite during scanning. MR imaging protocols utilized preoperatively were repeated on whole sample, reperfused ex vivo uterus specimens. Thermal properties including thermal diffusivity and thermal conductivity of the uterus and fibroids were determined using an invasive needle sensor device in 50% of the specimens. Acoustic property measurements (density, speed of sound and attenuation) were obtained for approximately 20% of the tissue samples using both through-transmission and radiation force balance techniques. Differences between fibroid and uterus and in vivo and ex vivo measurements were evaluated with a two-tailed Student t test.

RESULTS

Fourteen patients participated in the study and measurements were obtained from 22 unique fibroids. Of the 16 fibroids available for preoperative MRI testing, 69% demonstrated classic hypo-intensity relative to the myometrium, with the remainder presenting with iso- (25%) or hyper-intensity (6%). While thermal diffusivity was not significantly different between fibroid and myometrium tissues (0.217 ± 0.047 and 0.204 ± 0.039 mm² /s, respectively), the acoustic attenuation in fibroid tissue was significantly higher than myometrium (0.092 ± 0.021 and 0.052 ± 0.023 Np/cm/MHz, respectively). When comparing in vivo with ex vivo MRI T1 and T2 measurements in fibroids and myometrium tissue, the only difference was found in the fibroid T2 property (P < 0.05). Finally, the developed perfusion protocol successfully maintained tissue viability in ex vivo tissues as evaluated through histological analysis.

CONCLUSIONS

This study developed an MR-compatible extracorporeal perfusion technique that effectively maintains tissue viability, allowing for the direct measurement of patient-specific MR, thermal, and acoustic property values for both fibroid and myometrium tissues. These measured tissue property values will enable further development and validation of treatment planning models that can be utilized during MRgFUS uterine fibroid treatments.

Spectrum of Pitfalls, Pseudolesions, and Potential Misdiagnoses in Cirrhosis

OBJECTIVE

The purposes of this article are to review a variety of pitfalls in liver imaging that can lead to the inaccurate diagnosis of focal hepatic lesions in cirrhosis, to describe the pathophysiologic processes of these pitfalls, and to provide specific clues for achieving the correct diagnoses.

CONCLUSION

Cirrhosis complicates liver imaging. The distortion and replacement of normal liver parenchyma by fibrous and regenerative tissue can change the typical appearance of many benign lesions, causing them to be misinterpreted as malignancy. In addition, the high incidence and prevalence of hepatocellular carcinoma among patients with cirrhosis put radiologists on high alert for any suspicious findings, especially because not all hepatocellular carcinomas have a typical imaging appearance.

Reasons for different therapeutic effects of high-intensity focused ultrasound ablation on excised uterine fibroids with different signal intensities on T2-weighted MRI: a study of histopathological characteristics

OBJECTIVE

The objective of this study was to explore the correlations between the therapeutic effect of high intensity focused ultrasound (HIFU) and histopathological characteristics of excised uterine fibroids with different signal intensities as visualized on T2-weighted magnetic resonance imaging (MRI).

METHODS

We collected 47 specimens of uterine fibroids after surgical resection and classified them into four groups according to preoperative T2-weighted MRI hypo-intense, isointense, heterogeneous intense and homogeneous hyper-intense. Then, specimens in each group were irradiated by HIFU with the same parameters and the necrotic tissue volume was calculated. The smooth muscle cell (SMC) count and collagen fiber content were quantitatively measured and compared between different groups. We analyzed the correlation between the necrotic tissue volume and SMC count and the collagen fiber content.

RESULTS

Necrotic tissue volume gradually decreased from the hypo-intense group to the homogeneous hyper-intense group (p = .008). The SMC count from the hypo-intense group to the homogeneous hyper-intense group was 215.6 ± 59.3, 237.0(89.5), 232.3 ± 72.5 and 330.5 ± 30.9, respectively; collagen fiber content was 0.65 ± 0.07, 0.64 ± 0.10, 0.53 ± 0.11 and 0.41 ± 0.06, respectively. Comparison among the four groups showed that SMC count progressively increased (p = .001) but collagen fiber content progressively decreased (p = .000) from the hypo-intense group to the homogeneous hyper-intense group. Correlation analysis showed that necrotic tissue volume was negatively correlated with SMC count (R = -0.488, p=.013) but positively correlated with collagen fiber content (R = 0.534, p = .005).

CONCLUSIONS

Differences in histopathological characteristics may be one of the reasons for different therapeutic effects of HIFU ablation on uterine fibroids with different signal intensities on T2-weighted MRI.

Management of Uterine Fibroids: A Focus on Uterine-sparing Interventional Techniques

Uterine fibroids occur in approximately 50% of women over the age of 40 years, and an estimated 50% of those are symptomatic. Menorrhagia is the most common symptom and the primary indication for treatment, although bulk symptoms often occur and can be treated. Pharmacotherapy is typically inadequate unless it can be expected to successfully bridge to menopause or allow for a less-invasive intervention. However, hormonal therapies have risks. Hysterectomy is still the most commonly performed procedure for symptomatic fibroids and has the lowest rate of reintervention (compared with myomectomy or uterine artery embolization [UAE]), but rates of more serious complications are higher and patient satisfaction and ability to return to normal activities may also be less favorable. Myomectomy is not necessarily less morbid than hysterectomy and may have a greater failure rate than UAE. Techniques and devices vary with little standardization, and operator experience is crucial to success. The largest studies of UAE show very low rates of serious complications and rapid recovery. UAE significantly improves symptoms related to uterine fibroids in 85%-90% of patients. Herein, this article will discuss the nature of fibroids and their diagnosis, pharmacotherapy, surgical treatment, and nonsurgical interventional treatment, including UAE and magnetic resonance-guided focused ultrasound. (©) RSNA, 2016.

A feasibility study on monitoring the evolution of apparent diffusion coefficient decrease during thermal ablation

PURPOSE

Evaluate whether a decrease in apparent diffusion coefficient (ADC), associated with loss of tissue viability (LOTV), can be observed during the course of thermal ablation of the prostate.

METHODS

Thermal ablation was performed in a healthy in vivo canine prostate model (N = 2, ages: 5 yr healthy, mixed breed, weights: 13-14 kg) using a transurethral high-intensity ultrasound catheter and was monitored using a strategy that interleaves diffusion weighted images and gradient-echo images. The two sequences were used to measure ADC and changes in temperature during the treatment. Changes in temperature were used to compute expected changes in ADC. The difference between expected and measured ADC, ADCDIFF, was analyzed in regions ranging from moderate hyperthermia to heat fixation. A receiver operator characteristic (ROC) curve analysis was used to select a threshold of detection of LOTV. Time of threshold activation, tLOTV, was compared with time to reach CEM43 = 240, tDOSE.

RESULTS

The observed relationship between temperature and ADC in vivo (2.2%/ °C, 1.94%-2.47%/ °C 95% confidence interval) was not significantly different than the previously reported value of 2.4%/ °C in phantom. ADCDIFF changes after correction for temperature showed a mean decrease of 25% in ADC 60 min post-treatment in regions where sufficient thermal dose (CEM43 > 240) was achieved. Following our ROC analysis, a threshold of 2.25% decrease in ADCDIFF for three consecutive time points was chosen as an indicator of LOTV. The ADCDIFF was found to decrease quickly (1-2 min) after reaching CEM43 = 240 in regions associated with heat fixation and more slowly (10-20 min) in regions that received slower heating.

CONCLUSIONS

Simultaneous monitoring of ADC and temperature during treatment might allow for a more complete tissue viability assessment of ablative thermal treatments in the prostate. ADCDIFF decreases during the course of treatment may be interpreted as loss of tissue viability.

Mifepristone inhibits extracellular matrix formation in uterine leiomyoma

OBJECTIVE

To characterize the efficacy of mifepristone treatment on extracellular matrix (ECM) production in leiomyomas.

DESIGN

Laboratory study.

SETTING

University research laboratory.

PATIENT(S)

None.

INTERVENTION(S)

Treatment of human immortalized two-dimensional (2D) and three-dimensional (3D) leiomyoma and myometrial cells with mifepristone and the progestin promegestone (R5020).

MAIN OUTCOME MEASURE(S)

Expression of COL1A1, fibronectin, versican variant V0, and dermatopontin in treated leiomyoma cells by Western blot analysis and confirmatory immunohistochemistry staining of treated 3D cultures.

RESULT(S)

Treatment with progestin stimulated production of COL1A1, fibronectin, versican, and dermatopontin. Mifepristone treatment inhibited protein production of these genes, most notably with versican expression. Combination treatment with both the agonist and antagonist further inhibited protein expression of these genes. Immunohistochemistry performed on 3D cultures demonstrated generalized inhibition of ECM protein concentration.

CONCLUSION(S)

Our study demonstrated that the progesterone agonist R5020 directly stimulated extracellular matrix components COL1A1, fibronectin, versican, and dermatopontin production in human leiomyoma cells. Progesterone antagonist mifepristone decreased protein production of these genes to levels comparable with untreated leiomyoma cells.

Potential of minimally invasive procedures in the treatment of uterine fibroids: a focus on magnetic resonance-guided focused ultrasound therapy

Minimally invasive treatment options are an important part of the uterine fibroid-treatment arsenal, especially among younger patients and in those who plan future pregnancies. This article provides an overview of the currently available minimally invasive therapy options, with a special emphasis on a completely noninvasive option: magnetic resonance-guided focused ultrasound (MRgFUS). In this review, we describe the background of MRgFUS, the patient-selection criteria for MRgFUS, and how the procedure is performed. We summarize the published clinical trial results, and review the literature on pregnancy post-MRgFUS and on the cost-effectiveness of MRgFUS.

Update on Clinical Magnetic Resonance-Guided Focused Ultrasound Applications

In this review, several clinical applications of magnetic resonance (MR)-guided focused ultrasound (FUS) are updated. MR-guided FUS is used clinically for thermal ablation of uterine fibroids and bone metastases. Thousands of patients have successfully been treated. Transcranial MR-guided FUS has received CE certification for ablation of deep, central locations in the brain. Thermal ablation of specific parts of the thalamus can result in relief of the symptoms in a number of neurological disorders. Several approaches have been proposed for ablation of prostate and breast cancer and clinical trials should show the potential of MR-guided FUS for these and other applications.

Berberine inhibits the proliferation of human uterine leiomyoma cells

OBJECTIVE

To determine whether berberine (BBR), a naturally occurring plant-derived alkaloid, inhibits the proliferation of human uterine leiomyoma (UtLM) cells.

DESIGN

Laboratory research.

SETTING

Laboratory.

PATIENT(S)

UtLM and normal human uterine smooth muscle (UtSMC) cell lines.

INTERVENTION(S)

Treatment with [1] BBR (10, 20, and 50 μM), [2] BBR (20 and 50 μM) and/or 17β-estradiol (E2; 10 and 100 nM), and [3] BBR (20 and 50 μM) and/or progesterone (P4; 10 and 100 nM) for 24 or 72 hours.

MAIN OUTCOME MEASURE(S)

Cell proliferation, cell cycle, apoptosis, and related genes expression were determined.

RESULT(S)

BBR inhibited UtLM cell proliferation by inducing G2/M cell cycle arrest and apoptosis. Cell cycle G2/M phase-related genes were altered by BBR treatment: the expression of cyclin A1, cyclin B1, and Cdk1 were down-regulated, while Cdk4, p21, and p53 were up-regulated. BBR-treated cells stained positively for annexin V and manifested increased BAX expression. E2- and P4-induced UtLM cell proliferation was blocked by BBR treatment. In marked contrast, even the highest concentration of BBR (50 μM) did not influence cell proliferation in UtSMC cells.

CONCLUSION(S)

BBR selectively inhibits cellular proliferation and blocks E2- and P4-induced cell proliferation in UtLM but not in normal UtSMC cells. In addition, BBR did not demonstrate cytotoxicity effects in normal human UtSMCs. Our results suggest BBR could be a potential therapeutic agent for the treatment of uterine leiomyoma.

Treatment envelope evaluation in transcranial magnetic resonance-guided focused ultrasound utilizing 3D MR thermometry

BACKGROUND

Current clinical targets for transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) are all located close to the geometric center of the skull convexity, which minimizes challenges related to focusing the ultrasound through the skull bone. Non-central targets will have to be reached to treat a wider variety of neurological disorders and solid tumors. Treatment envelope studies utilizing two-dimensional (2D) magnetic resonance (MR) thermometry have previously been performed to determine the regions in which therapeutic levels of FUS can currently be delivered. Since 2D MR thermometry was used, very limited information about unintended heating in near-field tissue/bone interfaces could be deduced.

METHODS

In this paper, we present a proof-of-concept treatment envelope study with three-dimensional (3D) MR thermometry monitoring of FUS heatings performed in a phantom and a lamb model. While the moderate-sized transducer used was not designed for transcranial geometries, the 3D temperature maps enable monitoring of the entire sonication field of view, including both the focal spot and near-field tissue/bone interfaces, for full characterization of all heating that may occur. 3D MR thermometry is achieved by a combination of k-space subsampling and a previously described temporally constrained reconstruction method.

RESULTS

We present two different types of treatment envelopes. The first is based only on the focal spot heating-the type that can be derived from 2D MR thermometry. The second type is based on the relative near-field heating and is calculated as the ratio between the focal spot heating and the near-field heating. This utilizes the full 3D MR thermometry data achieved in this study.

CONCLUSIONS

It is shown that 3D MR thermometry can be used to improve the safety assessment in treatment envelope evaluations. Using a non-optimal transducer, it is shown that some regions where therapeutic levels of FUS can be delivered, as suggested by the first type of envelope, are not necessarily safely treated due to the amount of unintended near-field heating occurring. The results presented in this study highlight the need for 3D MR thermometry in tcMRgFUS.

Alternative therapies in management of leiomyomas

Leiomyomas are benign soft-tissue neoplasms that arise from smooth muscle. Relief of symptoms (abnormal uterine bleeding, pain, pressure) is the major goal in management of women with significant symptoms. For symptomatic myomas, hysterectomy is a definitive solution; however, there are emerging less-invasive options. Magnetic resonance imaging-guided focused ultrasound surgery, cryomyolysis, and temporary occlusion of the uterine arteries are treatment options that are minimally invasive interventions with the benefit of preserving the uterus. This review summarizes procedure techniques, eligibility, complications, and outcomes of these alternate therapies.

Paricalcitol, a vitamin d receptor activator, inhibits tumor formation in a murine model of uterine fibroids

We examined the antitumor and therapeutic potentials of paricalcitol, an analog of 1,25-dihydroxyvitamin D3 with lower calcemic activity, against uterine fibroids using in vitro and in vivo evaluations in appropriate uterine fibroid cells and animal models. We found that paricalcitol has potential to reduce the proliferation of the immortalized human uterine fibroid cells. For the in vivo study, we generated subcutaneous tumors by injecting the Eker rat-derived uterine leiomyoma cell line (ELT-3) rat uterine fibroid-derived cell line in athymic nude mice supplemented with estrogen pellets. These mice were administered with vehicle versus paricalcitol (300 ng/kg/d) or 1,25-dihydroxyvitamin D3 (500 ng/kg/d) for 4 consecutive weeks, and the data were analyzed. We found that while both paricalcitol and 1,25-dihydroxyvitamin D3 significantly reduced fibroid tumor size, the shrinkage was slightly higher in the paricalcitol-treated group. Together, our results suggest that paricalcitol may be a potential candidate for effective, safe, and noninvasive medical treatment option for uterine fibroids.

MR-monitored focused ultrasound using the acoustic-coupling water bath as an intrinsic high-mode dielectric resonator

The conventional set-up for MR-monitored focused ultrasound surgery includes a piezoelectric transducer and an acoustic-coupling water bath integrated into the MR patient table; a large surface RF coil is placed close to the patient or, alternatively, the body coil is used as the MR receiver. Potential disadvantages of this approach are that the body coil has low sensitivity because of its low filling factor and the local RF coil can interfere with and cause reflections of the ultrasound irradiation. In this article, a completely new approach is presented, in which an MR transmit/receive coil is not needed at all. Instead, the dimensions of the water bath are adjusted so that a high-order dielectric mode is excited, resulting in efficient MR excitation and reception at the transducer focal point. An example of monitoring ultrasound-mediated heating in a phantom is shown on a 7-T human system, although the new method can also be applied at lower fields.

Terminology and reporting criteria for radiofrequency ablation of tumors in the scientific literature: systematic review of compliance with reporting standards

OBJECTIVE

To perform a systematic review of compliance with standardized terminology and reporting criteria for radiofrequency (RF) tumor ablation, proposed by the International Working Group on Image-Guided Tumor Ablation in 2003, in the published reports.

MATERIALS AND METHODS

Literature search in the PubMed database was performed using index keywords, PubMed limit system, and eligibility criteria. The entire content of each article was reviewed to assess the terminology used for procedure terms, imaging findings, therapeutic efficacy, follow-up, and complications. Accuracy of the terminology and the use of alternative terms instead of standard terminology were analyzed. In addition, disparities in accuracy of terminology in articles according to the medical specialty and the type of radiology journal were evaluated.

RESULTS

Among the articles (n = 308) included in this study, the accuracy of the terms 'procedure or session', 'treatment', 'index tumor', 'ablation zone', 'technical success', 'primary technique effectiveness rate', 'secondary technique effectiveness rate', 'local tumor progression', 'major complication', and 'minor complication' was 97% (298/307), 97% (291/300), 8% (25/307), 65% (103/159), 55% (52/94), 33% (42/129), 94% (17/18), 45% (88/195), 99% (79/80), and 100% (77/77), respectively. The overall accuracy of each term showed a tendency to improve over the years. The most commonly used alternative terms for 'technical success' and 'local tumor progression' were 'complete ablation' and 'local (tumor) recurrence', respectively. The accuracy of terminology in articles published in radiology journals was significantly greater than that of terminology in articles published in non-radiology journals, especially in Radiology and The Journal of Vascular and Interventional Radiology.

CONCLUSION

The proposal for standardization of terminology and reporting criteria for RF tumor ablation has been gaining support according to the recently published scientific reports, especially in the field of radiology. However, more work is still needed for the complete standardization of terminology.

Sensitivity of myoma imaging using laparoscopic ultrasound compared with magnetic resonance imaging and transvaginal ultrasound

STUDY OBJECTIVE

To determine the efficacy of laparoscopic ultrasound (LUS) as compared with contrast-enhanced magnetic resonance imaging (CE-MRI) and transvaginal ultrasound (TVUS) in detection of uterine myomas.

DESIGN

Retrospective study of imaging methods used in a trial of LUS-guided radiofrequency volumetric thermal ablation in women with symptomatic myomas (Canadian Task Force classification II-2).

SETTING

Eleven medical university or private outpatient surgery clinics in the United States (nine sites) and Latin America (two sites).

PATIENTS

One hundred thirty-five women with symptomatic myomas and objectively confirmed moderate to severe heavy menstrual bleeding.

INTERVENTIONS

LUS-guided radiofrequency volumetric thermal ablation of myomas.

MEASUREMENTS AND MAIN RESULTS

Preoperative TVUS scans and CE-MRIs were read at each site, and all CE-MRIs were read by a central reader. LUS-guided scans were obtained intraoperatively by each surgeon by mapping the uterus just before radiofrequency volumetric thermal ablation. The imaging methods and their yields in terms of number of myomas found per subject were as follows: TVUS, 403 myomas (mean [SD] 3 [1.8]; range, 1-8); site CE-MRI, 562 myomas (4.2 [3.8]; range, 1-18); central reader, 619 myomas (4.6 [3.7]; range, 0-20); and LUS, 818 myomas (6.1 [4.9]; range, 1-29) (p < .001). LUS was superior to TVUS, CE-MRI, and the central reader for detection of small (≤1 cm(3)) myomas. Most imaged myomas were intramural: 197 (50.9%) by TVUS, 298 (55.5%) by site CE-MRI, 290 (48.7%) by the central reader, and 386 (48.5%) by LUS.

CONCLUSION

Compared with CE-MRI and TVUS, LUS demonstrates the most myomas, regardless of size or type.

Treatment of symptomatic uterine fibroids with green tea extract: a pilot randomized controlled clinical study

Background

Uterine fibroids (UFs, also known as leiomyoma) affect 70% of reproductive-age women. Imposing a major burden on health-related quality-of-life (HRQL) of premenopausal women, UF is a public health concern. There are no effective medicinal treatment options currently available for women with symptomatic UF.

Objectives

To evaluate the efficacy and safety of green tea extract (epigallocatechin gallate [EGCG]) on UF burden and quality of life in women with symptomatic UF, in a double-blinded, placebo-controlled randomized clinical trial.

Methods

A total of 39 reproductive-age women (age 18–50 years, day 3 serum follicle-stimulating hormone <10 \U/mL) with symptomatic UF were recruited for this study. All subjects had at least one fibroid lesion 2 cm³ or larger, as confirmed by transvaginal ultrasonography. The subjects were randomized to oral daily treatment with either 800 mg of green tea extract (45% EGCG) or placebo (800 mg of brown rice) for 4 months, and UF volumes were measured at the end, also by transvaginal ultrasonography. The fibroid-specific symptom severity and HRQL of these UF patients were scored at each monthly visit, using the symptom severity and quality-of-life questionnaires. Student’s t-test was used to evaluate statistical significance of treatment effect between the two groups.

Results

Of the final 39 women recruited for the study, 33 were compliant and completed all five visits of the study. In the placebo group (n = 11), fibroid volume increased (24.3%) over the study period; however, patients randomized to green tea extract (n = 22, 800 mg/day) treatment showed significant reduction (32.6%, P = 0.0001) in total UF volume. In addition, EGCG treatment significantly reduced fibroid-specific symptom severity (32.4%, P = 0.0001) and induced significant improvement in HRQL (18.53%, P = 0.01) compared to the placebo group. Anemia also significantly improved by 0.7 g/dL (P = 0.02) in the EGCG treatment group, while average blood loss significantly decreased from 71 mL/month to 45 mL/month (P = 0.001). No adverse effects, endometrial hyperplasia, or other endometrial pathology were observed in either group.

Conclusion

EGCG shows promise as a safe and effective therapeutic agent for women with symptomatic UFs. Such a simple, inexpensive, and orally administered therapy can improve women’s health globally.

Serum vitamin D3 level inversely correlates with uterine fibroid volume in different ethnic groups: a cross-sectional observational study

PURPOSE

Currently there is no effective medicinal treatment for uterine fibroids (UFs), a common health disorder that affects women of reproductive age. Identification of modifiable risk factors such as vitamin D (Vit D) deficiency could help develop novel strategies for the prevention and/or treatment of UFs. The purpose of this study was to identify whether low serum Vit D3 levels correlate with increased risk of UFs.

METHODS

A total of 154 premenopausal women were recruited for this cross-sectional study. The control group comprised 50 subjects with a normal, fibroid-free uterine structure, confirmed by transvaginal ultrasonography. The 104 case subjects had at least one fibroid lesion that was 2 cm(3) in volume or larger, confirmed by transvaginal ultrasonography. For each case subject, total uterine volume and total volume of all existing fibroids were measured in three perpendicular planes, with volume determined according to the prolate ellipse formula (a × b × c × 0.523), where a is height, b is width, and c is depth. Serum Vit D [25(OH) D3] levels were measured by radioimmunoassay. The independent t-test was used to compare serum Vit D levels across groups. Correlations were assessed by Spearman's rank correlation test.

RESULTS

Lower serum 25-(OH) Vit D levels were significantly associated with the occurrence of UFs (P = 0.01). A statistically significant inverse correlation was also observed between serum 25-(OH) Vit D levels and total UF volume (r = -0.31; P = 0.002) within the case cohort. Subjects with larger fibroid volumes had lower serum Vit D levels and vice versa. Data stratified for ethnicity showed a statistically significant inverse correlation between serum 25-(OH) Vit D levels and total fibroid volume in black subjects (r = -0.42; P = 0.001). An inverse correlation was also evident in white subjects (r = -0.86; P = 0.58) but this did not reach statistical significance.

CONCLUSION

Lower serum Vit D levels are inversely correlated with UF burden in different ethnic groups. Vit D deficiency is a possible risk factor for the occurrence of UFs.

Heavy menstrual flow: current and future trends in management

Menorrhagia accounts for a large number of secondary care referrals in the West. Women of different ages have different expectations from the treatment offered to them. Young women of reproductive age often demand treatment that simultaneously reduces bleeding, preserves fertility, and has very few side effects, whereas older women who ultimately wish to keep their reproductive organs may have reason to avoid hormonal manipulation. This article discusses possible management options and introduces a hierarchical approach to the management of menorrhagia based on the medical therapies and surgical procedures currently available. We explore the medical therapies for menorrhagia, which include hormone-modifying drug therapies and the new combined oral contraceptive pill. We also review novel fibroid surgical therapies and the latest surgical procedures, such as laparoscopic bilateral uterine artery occlusion, transvaginal Doppler-guided vascular clamp, and laparoscopic and intrauterine ultrasound-guided radiofrequency ablation.

MR-guided focused ultrasound (MRgFUS) is effective for the distinct pattern of uterine fibroids seen in African-American women: data from phase III/IV, non-randomized, multicenter clinical trials

Background

Uterine fibroids are common among women at the reproductive age. Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is a novel and a conservative treatment for symptomatic cases. The aim of the study was to evaluate the efficacy of MRgFUS in African-American (AA) women compared with that in non-African-Americans (non-AA).

Methods

A single-armed phase IV study was conducted to establish the efficacy of treatment in AA women. Comparison of patient, fibroid, and treatment characteristics from this trial was compared with that of the previously published phase III trial. Both studies were approved by the IRB of each medical center.

Results

Sixty-three AA and 59 non-AA women were treated with MRgFUS. Although AA women had a different pattern of disease, outcomes were similar in both groups. AA patients had a significant higher total number of fibroids compared with non-AA (median 6.0, interquartile range (IQR) 3.0–10.0 vs. 2.0, IQR 1.0–4.0, respectively, p < 0.001), although their total fibroid volume was significantly smaller (median 196.9 cm³, IQR 112.8–415.3 cm³ vs. 394.8 cm³, IQR 189.8–674.4 cm³, respectively, p < 0.001). AA women were younger compared with non-AA (mean ± SD 43.4 ± 5.1 vs. 46.3 ± 4.1 years of age, respectively, p = 0.001) when they presented for treatment. The rate of alternative treatments as well as fibroid-associated symptoms at follow-up time points (3, 6, 12, 24, and 36 months, period following MRgFUS treatment) did not differ according to race (p ≥ 0.62).

Conclusion

Despite differences in the pattern of fibroid disease, MRgFUS for uterine fibroids has a similar efficacy for AA women compared with non-AA women.

SonoKnife for ablation of neck tissue: in vivo verification of a computer layered medium model

PURPOSE

This study aimed to determine which treatment parameters of the SonoKnife device can be used to safely and effectively perform non-invasive thermal ablation of subcutaneous tissue.

METHODS

A three-dimensional computational layered medium model was constructed to simulate thermal ablation treatment of the SonoKnife device. The acoustic and thermal fields were calculated with the Fast Object-Oriented C++ Ultrasound-Simulator software and a finite difference code, respectively. Subcutaneous tissue was represented as layers of skin, fat and muscle. The simulations were conducted for ultrasound frequencies of 1 or 3.5 MHz. The thermal dose model was used to predict the size and location of the ablated regions. The computer simulations were verified by using the SonoKnife to perform subcutaneous ablations in the neck area of healthy pigs, in vivo. Triphenyltetrazolium chloride viability stain was used to differentiate viable tissue from ablated regions ex vivo.

RESULTS

The simulations for the layered medium model suggest that operating the SonoKnife at frequency of 1 MHz is more effective and safer than 3.5 MHz providing skin cooling is applied prior to ablation. These predictions were in agreement with the results observed in the animal studies. The required sonication time for ablation increased from 50 to 300 s by using 1 MHz.

CONCLUSION

Our modelling and animal studies suggest that 1 MHz with pretreatment skin cooling are the optimal settings to operate the SonoKnife to safely and effectively perform subcutaneous thermal ablation of porcine skin. More work is needed to optimise skin cooling and define the optimal sonication time.

Volumetric MR-guided high-intensity focused ultrasound ablation with a one-layer strategy to treat large uterine fibroids: initial clinical outcomes

PURPOSE

To evaluate initial clinical outcomes of volumetric magnetic resonance (MR)-guided high-intensity focused ultrasound (HIFU) ablation by using a one-layer strategy to treat large (>10 cm in diameter) uterine fibroids, with investigation of the correlation between effectiveness of the one-layer strategy and dynamic contrast material-enhanced (DCE) MR parameters.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. Twenty-seven women (mean age, 44.5 years) with 27 large uterine fibroids (mean diameter, 11.3 cm ± 1.4 [standard deviation] [range, 10.1-16.0 cm]; fibroid volume, 502.5 mL ± 214.3 [range, 253.8-1184.0 mL]) underwent volumetric MR-guided HIFU ablation with a one-layer strategy. (All treatment cells were placed in one coronal plane at a depth of half to anterior two-thirds of the anteroposterior dimension of fibroids.) Treatment time, immediate nonperfused volume (NPV), and effectiveness of a one-layer strategy (ratio of immediate NPV to total volume of treatment cells planned) correlating with baseline DCE MR parameters (volume transfer constant [K(trans)], fractional extravascular extracellular space, and fractional blood plasma volume [Pearson correlation test]), complications, 3-month follow-up volumes, and symptom severity score (SSS) changes (paired t test) were assessed retrospectively.

RESULTS

All treatments showed technical success in one session (mean treatment time, 166.2 minutes ± 38.9). NPV was 301.3 mL ± 119.1, which was 64.2% ± 19.9 (<50%, n = 4; ≥ 50%, n = 23) of fibroid volume. Ratio of immediate NPV to total volume of treatment cells (1.79 ± 0.61) negatively correlated with DCE MR imaging K(trans) values (r = -0.426, P = .017). Minor complications occurred in five patients (18.5% [thermal injury of abdominal wall, n = 3; 30-day leg numbness, n = 1; cystitis, n = 1]). At 3-month follow-up (n = 18), mean SSS had decreased from 37.4 at baseline to 24.0 (P < .001), and volume reduction ratio was 0.64 ± 0.15 (P < .001).

CONCLUSION

Volumetric MR-guided HIFU ablation with a one-layer strategy is safe and effective for treatment of large uterine fibroids. Effectiveness of this strategy showed a significant negative correlation with K(trans) values at baseline DCE MR imaging.

Harmonic Motion Imaging (HMI) for Tumor Imaging and Treatment Monitoring

Palpation is an established screening procedure for the detection of several superficial cancers including breast, thyroid, prostate, and liver tumors through both self and clinical examinations. This is because solid masses typically have distinct stiffnesses compared to the surrounding normal tissue. In this paper, the application of Harmonic Motion Imaging (HMI) for tumor detection based on its stiffness as well as its relevance in thermal treatment is reviewed. HMI uses a focused ultrasound (FUS) beam to generate an oscillatory acoustic radiation force for an internal, non-contact palpation to internally estimate relative tissue hardness. HMI studies have dealt with the measurement of the tissue dynamic motion in response to an oscillatory acoustic force at the same frequency, and have been shown feasible in simulations, phantoms, ex vivo human and bovine tissues as well as animals in vivo. Using an FUS beam, HMI can also be used in an ideal integration setting with thermal ablation using high-intensity focused ultrasound (HIFU), which also leads to an alteration in the tumor stiffness. In this paper, a short review of HMI is provided that encompasses the findings in all the aforementioned areas. The findings presented herein demonstrate that the HMI displacement can accurately depict the underlying tissue stiffness, and the HMI image of the relative stiffness could accurately detect and characterize the tumor or thermal lesion based on its distinct properties. HMI may thus constitute a non-ionizing, cost-efficient and reliable complementary method for noninvasive tumor detection, localization, diagnosis and treatment monitoring.

SonoKnife: feasibility of a line-focused ultrasound device for thermal ablation therapy

PURPOSE

To evaluate the feasibility of line-focused ultrasound for thermal ablation of superficially located tumors.

METHODS

A SonoKnife is a cylindrical-section ultrasound transducer designed to radiate from its concave surface. This geometry generates a line-focus or acoustic edge. The motivation for this approach was the noninvasive thermal ablation of advanced head and neck tumors and positive neck nodes in reasonable treatment times. Line-focusing may offer advantages over the common point-focusing of spherically curved radiators such as faster coverage of a target volume by scanning of the acoustic edge. In this paper, The authors report studies using numerical models and phantom and ex vivo experiments using a SonoKnife prototype.

RESULTS

Acoustic edges were generated by cylindrical-section single-element ultrasound transducers numerically, and by the prototype experimentally. Numerically, simulations were performed to characterize the acoustic edge for basic design parameters: transducer dimensions, line-focus depth, frequency, and coupling thickness. The dimensions of the acoustic edge as a function of these parameters were determined. In addition, a step-scanning simulation produced a large thermal lesion in a reasonable treatment time. Experimentally, pressure distributions measured in degassed water agreed well with acoustic simulations, and sonication experiments in gel phantoms and ex vivo porcine liver samples produced lesions similar to those predicted with acoustic and thermal models.

CONCLUSIONS

Results support the feasibility of noninvasive thermal ablation with a SonoKnife.

See, reach, treat: ultrasound-triggered image-guided drug delivery

The integration of therapeutic interventions with diagnostic imaging has been recognized as one of the next technological developments that will have a major impact on medical treatments. Therapeutic applications using ultrasound, for example thermal ablation, hyperthermia or ultrasound-induced drug delivery, are examples for image-guided interventions that are currently being investigated. While thermal ablation using magnetic resonance-guided high-intensity focused ultrasound is entering the clinic, ultrasound-mediated drug delivery is still in a research phase, but holds promise to enable new applications in localized treatments. The use of ultrasound for the delivery of drugs has been demonstrated, particularly in the field of cardiology and oncology for a variety of therapeutics ranging from small-molecule drugs to biologics and nucleic acids exploiting temperature- or pressure-mediated delivery schemes.

Focused ultrasound surgery in oncology: overview and principles

Focused ultrasound surgery (FUS) is a noninvasive image-guided therapy and an alternative to surgical interventions. It presents an opportunity to revolutionize cancer therapy and to affect or change drug delivery of therapeutic agents in new focally targeted ways. In this article the background, principles, technical devices, and clinical cancer applications of image-guided FUS are reviewed.

Image Registered Gastroscopic Ultrasound (IRGUS) in human subjects: a pilot study to assess feasibility

BACKGROUND AND STUDY AIMS

Endoscopic ultrasound (EUS) is a complex procedure due to the subtleties of ultrasound interpretation, the small field of observation, and the uncertainty of probe position and orientation. Animal studies demonstrated that Image Registered Gastroscopic Ultrasound (IRGUS) is feasible and may be superior to conventional EUS in efficiency and image interpretation. This study explores whether these attributes of IRGUS will be evident in human subjects, with the aim of assessing the feasibility, effectiveness, and efficiency of IRGUS in patients with suspected pancreatic lesions.

PATIENTS AND METHODS

This was a prospective feasibility study at a tertiary care academic medical center in human patients with pancreatic lesions on computed tomography (CT) scan. Patients who were scheduled to undergo conventional EUS were randomly chosen to undergo their procedure with IRGUS. Main outcome measures included feasibility, ease of use, system function, validated task load (TLX) assessment instrument, and IRGUS experience questionnaire.

RESULTS

Five patients underwent IRGUS without complication. Localization of pancreatic lesions was accomplished efficiently and accurately (TLX temporal demand 3.7 %; TLX effort 8.6 %). Image synchronization and registration was accomplished in real time without procedure delay. The mean assessment score for endoscopist experience with IRGUS was positive (66.6 ± 29.4). Real-time display of CT images in the EUS plane and echoendoscope orientation were the most beneficial characteristics.

CONCLUSIONS

IRGUS appears feasible and safe in human subjects, and efficient and accurate at identification of probe position and image interpretation. IRGUS has the potential to broaden the adoption of EUS techniques and shorten EUS learning curves. Clinical studies comparing IRGUS with conventional EUS are ongoing.

Doppler signals observed during high temperature thermal ablation are the result of boiling

PURPOSE

To elucidate the causation mechanism of Spectral Doppler ultrasound signals (DUS) observed during high temperature thermal ablation and evaluate their potential for image-guidance.

METHODS

Sixteen ex vivo ablations were performed in fresh turkey breast muscle, eight with radiofrequency ablation (RFA) devices, and eight with a conductive interstitial thermal therapy (CITT) device. Temperature changes in the ablation zone were measured with thermocouples located at 1 to 10 mm away from the ablation probes. Concomitantly, DUS were recorded using a standard diagnostic ultrasound scanner. Retrospectively, sustained observations of DUS were correlated with measured temperatures. Sustained DUS was arbitrarily defined as the Doppler signals lasting more than 10 s as observed in the diagnostic ultrasound videos captured from the scanner.

RESULTS

For RFA experiments, minimum average temperature (T1 +/- SD) at which sustained DUS were observed was 97.2 +/- 7.3 degrees C, while the maximum average temperature (T2 +/- SD) at which DUS were not seen was 74.3 +/- 9.1 degrees C. For CITT ablation, T1 and T2 were 95.7 +/- 5.9 degrees C and 91.6 +/- 7.2 degrees C, respectively. It was also observed, especially during CITT ablation, that temperatures remained relatively constant during Doppler activity.

CONCLUSIONS

The value of T1 was near the standard boiling point of water (99.61 degrees C) while T2 was below it. Together, T1 and T2 support the conclusion that DUS during high temperature thermal ablation are the result of boiling (phase change). This conclusion is also supported by the nearly constant temperature histories maintained at locations from which DUS emanated.