Unbiased and efficient estimation of the volume of the fibroid uterus using the Cavalieri method and magnetic resonance imaging

Incidence and changes in endometrial-leiomyoma fistula following uterine artery embolization: a single-center retrospective analysis

OBJECTIVES

To investigate whether the number and size of endometrial-leiomyoma fistulas (ELFs) change following uterine artery embolization (UAE) for leiomyoma and the correlation between ELFs and vaginal discharge (VD).

MATERIALS & METHODS

This study was a retrospective analysis of 100 patients who underwent UAE at a single institution between May 2016 and March 2021. They all underwent MRI at baseline, 4 months, and 1 year after UAE. The number and size of the ELFs were compared with the MRI images each time. The ELF tumor characteristics and the correlation between the ELFs and VD were assessed. Additional gynecologic interventions due to VD associated with ELFs were evaluated.

RESULTS

No ELF was observed at baseline. Ten ELFs were noted in nine patients at 4 months, and 35 ELFs were noted in 32 patients 1 year after UAE. The ELFs significantly increased over time (p = 0.004, baseline vs. 4 months; p < 0.001, 4 months vs. 1 year). The ELF size did not significantly change over time (p = 0.941). The tumors developing ELFs after UAE were mainly located at the submucosal or intramural area contacting the endometrium at baseline, with a mean size of 7.1 (2.6) cm. Nineteen patients (19%) had VD 1 year after UAE. There was no significant correlation between VD and the number of ELFs (p = 0.80). No patients underwent additional gynecologic interventions due to VD associated with ELFs.

CONCLUSION

ELFs increased in number and did not disappear over time after UAE in most tumors.

CLINICAL RELEVANCE STATEMENT

Despite the MR imaging findings, within the limited data of this study, ELFs were not seemingly associated with clinical symptoms, including VD.

KEY POINTS

• Endometrial-leiomyoma fistula (ELF) is a complication of uterine artery embolization (UAE). • ELFs increased in number over time after UAE and did not disappear in most tumors. • Most tumors developing ELFs after UAE were located near/contacted the endometrium and were larger.

Measurement of changes in uterine and fibroid volume during treatment of heavy menstrual bleeding (HMB)

STUDY QUESTION

Does application of an unbiased method for analysis of magnetic resonance (MR) images reveal any effect on uterine or fibroid volume from treatment of heavy menstrual bleeding (HMB) with three 12-week courses of the selective progesterone receptor modulator ulipristal acetate (SPRM-UPA)?

SUMMARY ANSWER

Application of an unbiased method for analysis of MR images showed that treatment of HMB with SPRM-UPA was not associated with a significant reduction in the volume of the uterus or in the volume of uterine fibroids.

WHAT IS KNOWN ALREADY

SPRM-UPA shows therapeutic efficacy for treating HMB. However, the mechanism of action (MoA) is not well understood and there have been mixed reports, using potentially biased methodology, regarding whether SPRM-UPA has an effect on the volume of the uterus and fibroids.

STUDY DESIGN SIZE DURATION

In a prospective clinical study (with no comparator), 19 women with HMB were treated over a period of 12 months with SPRM-UPA and uterine and fibroid size were assessed with high resolution structural MRI and stereology.

PARTICIPANTS/MATERIALS SETTING METHODS

A cohort of 19 women aged 38-52 years (8 with and 11 without fibroids) were treated with three 12-week courses of 5 mg SPRM-UPA given daily, with four weeks off medication in-between treatment courses. Unbiased estimates of the volume of uterus and total volume of fibroids were obtained at baseline, and after 6 and 12 months of treatment, by using the Cavalieri method of modern design-based stereology in combination with magnetic resonance imaging (MRI).

MAIN RESULTS AND THE ROLE OF CHANCE

Bland-Altman plots showed good intra-rater repeatability and good inter-rater reproducibility for measurement of the volume of both fibroids and the uterus. For the total patient cohort, two-way ANOVA did not show a significant reduction in the volume of the uterus after two or three treatment courses of SPRM-UPA (P = 0.51), which was also the case when the groups of women with and without fibroids were considered separately (P = 0.63). One-way ANOVA did not show a significant reduction in total fibroid volume in the eight patients with fibroids (P = 0.17).

LIMITATIONS REASONS FOR CAUTION

The study has been performed in a relatively small cohort of women and simulations that have subsequently been performed using the acquired data have shown that for three time points and a group size of up to 50, with alpha (Type I Error) and beta (Type II Error) set to 95% significance and 80% power, respectively, at least 35 patients would need to be recruited in order for the null hypothesis (that there is no significant reduction in total fibroid volume) to be potentially rejected.

WIDER IMPLICATIONS OF THE FINDINGS

The imaging protocol that we have developed represents a generic paradigm for measuring the volume of the uterus and uterine fibroids that can be readily incorporated in future studies of medical treatments of HMB. In the present study, SPRM-UPA failed to produce a significant reduction in the volume of the uterus or the total volume of fibroids (which were present in approximately half of the patients) after either two or three 12-week courses of treatment. This finding represents a new insight in respect of the management of HMB using treatment strategies that target hormone-dependence.

STUDY FUNDING/COMPETING INTERESTS

The UPA Versus Conventional Management of HMB (UCON) trial was funded by the EME Programme (Medical Research Council (MRC) and National Institutes of Health Research (NIHR)) (12/206/52). The views expressed in this publication are those of the authors and not necessarily those of the Medical Research Council, National Institute for Health Research, or Department of Health and Social Care.Medical Research Council (MRC) Centre grants to the Centre for Reproductive Health (CRH) (G1002033 and MR/N022556/1) are also gratefully acknowledged. H.C. has clinical research support for laboratory consumables and staff from Bayer AG and provides consultancy advice (All paid to Institution) for Bayer AG, PregLem SA, Gedeon Richter, Vifor Pharma UK Ltd, AbbVie Inc., and Myovant Sciences GmbH. H.C. has received royalties from UpToDate for an article on abnormal uterine bleeding. L.W. has received grant funding from Roche Diagnostics (Paid to Institution). All other authors have no conflicts to declare.

TRIAL REGISTRATION NUMBER

The study reported here is an embedded mechanism of action study (no comparator) within the UCON clinical trial (registration ISRCTN: 20426843).

Applications of various stereological tools for estimation of biological tissues

To provide concise and brief important stereological application methods and techniques for estimating biological tissues. Stereology studies the quantity of biological tissue using little practice and the low price of counting and preparing tissue slices to obtain direct and accurate results. Since their establishment, the stereological techniques underwent much improvement, thus allowing more precise analysis of target structures using various approaches. Using stereological tools, advances in stereological techniques made the target tissues or organs represented by 2D instead of 3D dimensions. Process tools estimate volume, area and length. According to the exciting tissue and aims, the stereological tools perform differently. This review summarizes various stereological tools and techniques, providing brief information about the orientation method, slicer probe method, Delesse's principle, Cavalieri principle, disector, fractionator, nucleator, virtual cycloids and saucer, which are described in detail.

Randomised Controlled Trial of Particles Used in Uterine fibRoid Embolisation (PURE): Non-Spherical Polyvinyl Alcohol Versus Calibrated Microspheres

Purpose

The PURE study is a randomised controlled trial (RCT) comparing the clinical and MRI outcomes of patients treated with non-spherical polyvinyl alcohol, ns-PVA (Contour PVA–Boston Scientific–355–500 & 500–700 microns) versus calibrated hydrogel microspheres (Embozene–Varian Inc–700 & 900 microns) for symptomatic uterine fibroids.

Materials and Methods

Prospective, ethically approved non-sponsored RCT in 84 patients in a single UK tertiary IR unit, ISRCTN registry trial number ISRCTN18191539 in 2013 and 2014. All patients with symptomatic fibroid disease were eligible. UAE followed a standardised protocol with UFS-QOL and contrast-enhanced MRI before and 6 months post UAE. Outcome measures included: (1) Uterine Fibroid Symptom and Quality of Life questionnaire (UFS-QOL). (2) Percentage total and dominant fibroid infarction. (3) Uterine and dominant fibroid volume reduction. (4) Volume of embolics.

Results

Sixty-three patients completed the QOL follow-up (33 ns-PVA vs 30 Embozenes), the groups were equivalent at baseline. Patients were followed up for 6 months following UAE. There was no significant difference in symptom scores or HR-QOL between ns-PVA and Embozenes, p = 0.67 and 0.21, respectively. 92.7% of patients treated with ns-PVA achieved > 90% dominant fibroid infarction versus 61.8% treated with Embozenes (p = 0.0016). 66% of patients treated with ns = PVA achieved > 90% total fibroid percentage infarction compared with 35% in the Embozene group (p = 0.011). The mean vials/syringes used were 5.2 with Embozenes versus 4.1 using PVA (p = 0.08).

Conclusion

The PURE study informs IRs regarding the efficacy of embolic agents in UAE, with superior fibroid infarction on MRI using ns-PVA versus Embozenes however no significant difference in clinical outcomes at 6 months after UAE.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00270-021-02977-0.

Timing of Uterine Artery Embolization for Leiomyoma during the Menstrual Cycle

PURPOSE

To investigate differences in outcomes of uterine artery embolization (UAE) for leiomyoma when performed during different phases of the menstrual cycle.

MATERIALS AND METHODS

In this single-institution retrospective analysis, 111 premenopausal patients (median [range] age, 44 [33-52] years) undergoing UAE for symptomatic leiomyoma between June 2014 and February 2020 were included. Twenty-one patients underwent UAE in the menstrual phase (the early follicular phase), 27 in the late follicular phase, and 63 in the luteal phase. Baseline characteristics and technical and peri-procedural outcomes were compared among groups. Leiomyoma infarction on contrast-enhanced magnetic resonance imaging 1 week after UAE and 4-month outcomes, including changes in the Uterine Fibroid Symptom and Quality of Life questionnaire scores, the volume reduction rates of the uterus and largest leiomyoma, follicle stimulating hormone values, adverse events, and amenorrhea, were compared among groups.

RESULTS

A 4-month follow-up was completed for all patients. No significant differences were observed among groups in baseline characteristics or technical and peri-procedural outcomes. There were no significant differences in the multivariate-adjusted 1-week infarction rates of all leiomyoma volumes (P = .161) or multivariate-adjusted 4-month outcomes, including changes in the Uterine Fibroid Symptom and Quality of Life questionnaire symptoms and total scores (P = .864 and P = .798, respectively), the volume reduction rates of the uterus and the largest leiomyoma (P = .865 and P = .965, respectively), and follicle stimulating hormone values (P = .186) among the groups. No significant differences were noted in the 4-month adverse events (P = .260) or amenorrhea (P = .793) among the groups.

CONCLUSIONS

The present study demonstrated no significant differences in the outcomes of UAE for leiomyoma when performed during different phases of the menstrual cycle.

Selective progesterone receptor modulators (SPRMs) for uterine fibroids

BACKGROUND

Uterine fibroids are smooth muscle tumours arising from the uterus. These tumours, although benign, are commonly associated with abnormal uterine bleeding, bulk symptoms and reproductive dysfunction. The importance of progesterone in fibroid pathogenesis supports selective progesterone receptor modulators (SPRMs) as effective treatment. Both biochemical and clinical evidence suggests that SPRMs may reduce fibroid growth and ameliorate symptoms. SPRMs can cause unique histological changes to the endometrium that are not related to cancer, are not precancerous and have been found to be benign and reversible. This review summarises randomised trials conducted to evaluate the effectiveness of SPRMs as a class of medication for treatment of individuals with fibroids.

OBJECTIVES

To evaluate the effectiveness and safety of SPRMs for treatment of premenopausal women with uterine fibroids.

SEARCH METHODS

We searched the Specialised Register of the Cochrane Gynaecology and Fertility Group, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and clinical trials registries from database inception to May 2016. We handsearched the reference lists of relevant articles and contacted experts in the field to request additional data.

SELECTION CRITERIA

Included studies were randomised controlled trials (RCTs) of premenopausal women with fibroids who were treated for at least three months with a SPRM.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed all eligible studies identified by the search. We extracted data and assessed risk of bias independently using standard forms. We analysed data using mean differences (MDs) or standardised mean differences (SMDs) for continuous data and odds ratios (ORs) for dichotomous data. We performed meta-analyses using the random-effects model. Our primary outcome was change in fibroid-related symptoms.

MAIN RESULTS

We included in the review 14 RCTs with a total of 1215 study participants. We could not extract complete data from three studies. We included in the meta-analysis 11 studies involving 1021 study participants: 685 received SPRMs and 336 were given a control intervention (placebo or leuprolide). Investigators evaluated three SPRMs: mifepristone (five studies), ulipristal acetate (four studies) and asoprisnil (two studies). The primary outcome was change in fibroid-related symptoms (symptom severity, health-related quality of life, abnormal uterine bleeding, pelvic pain). Adverse event reporting in the included studies was limited to SPRM-associated endometrial changes. More than half (8/14) of these studies were at low risk of bias in all domains. The most common limitation of the other studies was poor reporting of methods. The main limitation for the overall quality of evidence was potential publication bias. SPRM versus placebo SPRM treatment resulted in improvements in fibroid symptom severity (MD -20.04 points, 95% confidence interval (CI) -26.63 to -13.46; four RCTs, 171 women, I² = 0%; moderate-quality evidence) and health-related quality of life (MD 22.52 points, 95% CI 12.87 to 32.17; four RCTs, 200 women, I² = 63%; moderate-quality evidence) on the Uterine Fibroid Symptom Quality of Life Scale (UFS-QoL, scale 0 to 100). Women treated with an SPRM showed reduced menstrual blood loss on patient-reported bleeding scales, although this effect was small (SMD -1.11, 95% CI -1.38 to -0.83; three RCTs, 310 women, I² = 0%; moderate-quality evidence), along with higher rates of amenorrhoea (29 per 1000 in the placebo group vs 237 to 961 per 1000 in the SPRM group; OR 82.50, 95% CI 37.01 to 183.90; seven RCTs, 590 women, I² = 0%; moderate-quality evidence), compared with those given placebo. We could draw no conclusions regarding changes in pelvic pain owing to variability in the estimates. With respect to adverse effects, SPRM-associated endometrial changes were more common after SPRM therapy than after placebo (OR 15.12, 95% CI 6.45 to 35.47; five RCTs, 405 women, I² = 0%; low-quality evidence). SPRM versus leuprolide acetate In comparing SPRM versus other treatments, two RCTs evaluated SPRM versus leuprolide acetate. One RCT reported primary outcomes. No evidence suggested a difference between SPRM and leuprolide groups for improvement in quality of life, as measured by UFS-QoL fibroid symptom severity scores (MD -3.70 points, 95% CI -9.85 to 2.45; one RCT, 281 women; moderate-quality evidence) and health-related quality of life scores (MD 1.06 points, 95% CI -5.73 to 7.85; one RCT, 281 women; moderate-quality evidence). It was unclear whether results showed a difference between SPRM and leuprolide groups for reduction in menstrual blood loss based on the pictorial blood loss assessment chart (PBAC), as confidence intervals were wide (MD 6 points, 95% CI -40.95 to 50.95; one RCT, 281 women; low-quality evidence), or for rates of amenorrhoea (804 per 1000 in the placebo group vs 732 to 933 per 1000 in the SPRM group; OR 1.14, 95% CI 0.60 to 2.16; one RCT, 280 women; moderate-quality evidence). No evidence revealed differences between groups in pelvic pain scores based on the McGill Pain Questionnaire (scale 0 to 45) (MD -0.01 points, 95% CI -2.14 to 2.12; 281 women; moderate-quality evidence). With respect to adverse effects, SPRM-associated endometrial changes were more common after SPRM therapy than after leuprolide treatment (OR 10.45, 95% CI 5.38 to 20.33; 301 women; moderate-quality evidence).

AUTHORS' CONCLUSIONS

Short-term use of SPRMs resulted in improved quality of life, reduced menstrual bleeding and higher rates of amenorrhoea than were seen with placebo. Thus, SPRMs may provide effective treatment for women with symptomatic fibroids. Evidence derived from one RCT showed no difference between leuprolide acetate and SPRM with respect to improved quality of life and bleeding symptoms. Evidence was insufficient to show whether effectiveness was different between SPRMs and leuprolide. Investigators more frequently observed SPRM-associated endometrial changes in women treated with SPRMs than in those treated with placebo or leuprolide acetate. As noted above, SPRM-associated endometrial changes are benign, are not related to cancer and are not precancerous. Reporting bias may impact the conclusion of this meta-analysis. Well-designed RCTs comparing SPRMs versus other treatments are needed.

Structured imaging technique in the gynecologic office for the diagnosis of abnormal uterine bleeding

The aim in the diagnosis of abnormal uterine bleeding (AUB) is to identify the bleeding cause, which can be classified by the PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy (and hyperplasia), Coagulopathy, Ovulatory disorders, Endometrial, Iatrogenic and Not otherwise classified) classification system. In a gynecologic setting, the first step is most often to identify structural abnormalities (PALM causes). Common diagnostic options for the identification of the PALM include ultrasonography, endometrial sampling, and hysteroscopy. These options alone or in combination are sufficient for the diagnosis of most women with AUB. Contrast sonography with saline or gel infusion, three-dimensional ultrasonography, and magnetic resonance imaging may be included.

AIM

The aim of this article is to describe how a simple structured transvaginal ultrasound can be performed and implemented in the common gynecologic practice to simplify the diagnosis of AUB and determine when additional invasive investigations are required. Structured transvaginal ultrasound for the identification of the most common endometrial and myometrial abnormalities and the most common ultrasound features are described. Moreover, situations where magnetic resonance imaging may be included are described. This article proposes a diagnostic setup in premenopausal women for the classification of AUB according to the PALM-COEIN system. Moreover, a future diagnostic setup for fast-track identification of endometrial cancer in postmenopausal women based on a structured evaluation of the endometrium is described.