Clinical efficacy and safety of ultrasound-guided high-intensity focused ultrasound for breast fibroadenoma: a systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review and meta-analysis was to assess the clinical efficacy and safety of ultrasound (US)-guided high intensity focused ultrasound (HIFU) in the treatment of breast fibroadenoma in different studies.

METHODS

Studies evaluating the efficacy and safety of US-guided HIFU in the treatment of histologically-proven FA with follow-up outcomes of more than 3 months were searched through MEDLINE/PubMed databases. Volume reduction rate (VRR) and side effects were extracted and compared for further analysis.

RESULTS

Of 29 identified articles, 10 studies involving 385 women and more than 545 FAs met the inclusion criteria. The mean VRR at 6 months and 12 months after HIFU was 52.00% and 72.00%. In terms of intraoperative safety, nine studies reported mild to moderate pain, with an average visual analogue scale (VAS) score ranging from 1.60 to 7.10. The most common postoperative side effect associated with HIFU was subcutaneous ecchymosis and less frequent were pain, erythema, and skin pigmentation, most of which disappeared within weeks. No serious side effects were observed.

CONCLUSION

S-guided HIFU is an effective and safe noninvasive treatment for breast FA that does not cause serious side effects. Further studies are needed to explore crucial influencing factors of VRR.

Tissue Ablation: Applications and Perspectives

Tissue ablation techniques have emerged as a critical component of modern medical practice and biomedical research, offering versatile solutions for treating various diseases and disorders. Percutaneous ablation is minimally invasive and offers numerous advantages over traditional surgery, such as shorter recovery times, reduced hospital stays, and decreased healthcare costs. Intra-procedural imaging during ablation also allows precise visualization of the treated tissue while minimizing injury to the surrounding normal tissues, reducing the risk of complications. Here, the mechanisms of tissue ablation and innovative energy delivery systems are explored, highlighting recent advancements that have reshaped the landscape of clinical practice. Current clinical challenges related to tissue ablation are also discussed, underlining unmet clinical needs for more advanced material-based approaches to improve the delivery of energy and pharmacology-based therapeutics.

High intensity focused ultrasound in treating great saphenous vein incompetence: Perioperative and 1-year outcomes

BACKGROUND

To investigate the use of high intensity focused ultrasound (HIFU) for great saphenous vein (GSV) incompetence.

MATERIAL AND METHODS

Patients with GSV incompetence underwent HIFU. The primary endpoint was the rate of GSV target segment shrinkage or closure after 1 year.

RESULTS

Out of 188 limbs treated, the GSV treated segment shrinkage/closure rate at 1 week, 3 months, 6 months, and 12 months was 93.3%, 98.2%, 97.6%, and 98.3%, respectively.

CONCLUSION

These preliminary results suggest that HIFU holds promise for the treatment of GSV incompetence. Further trials are needed to compare it with other techniques and assess long-term outcomes.

MR-guided percutaneous microwave coagulation of small breast tumors

BACKGROUND

To evaluate the technical success and patient safety of magnetic resonance-guided percutaneous microwave coagulation (MR-guided PMC) for breast malignancies.

METHODS

From May 2018 to December 2019, 26 patients with breast tumors measuring 2 cm or less were recruited to participate in a prospective, single-institution clinical study. The primary endpoint of this study was the evaluation of treatment efficacy for each patient. Histochemical staining with α-nicotinamide adenine dinucleotide and reduced (NADH)-diaphorase was used to determine cell viability following and efficacy of PMC. The complications and self-reported sensations from all patients during and after ablation were also assessed. The technical success of the PMC procedure was defined when the area of the NADH-diaphorase negative region fully covered the hematoxylin-eosin (H&E) staining region in the tumor.

RESULTS

All patients had a complete response to ablation with no residual carcinoma on histopathological specimen. The mean energy, ablation duration, and procedure duration per tumor were 36.0 ± 4.2 kJ, 252.9 ± 30.9 S, and 104.2 ± 13.5 min, respectively. During the ablation, 14 patients underwent prolonged ablation time, and 1 patient required adjusting of the antenna position. Eleven patients had feelings of subtle heat or swelling, and 3 patients experienced slight pain. After ablation, one patient took two painkillers because of moderate pain, and no patients had postoperative oozing or other complications after PMC. Induration around the ablation area appeared in 16 patients.

CONCLUSION

MR-guided PMC of small breast tumors is feasible and could be applied in clinical practice in the future.

CRITICAL RELEVANCE STATEMENT

MR-guided PMC of small breast tumors is feasible and could be applied in clinical practice in the future.

KEY POINTS

• MR-guided PMC of small breast tumors is feasible. • PMC was successfully performed for all patients. • All patients were satisfied with the final cosmetic result.

Masked Modeling-Based Ultrasound Image Classification via Self-Supervised Learning

Recently, deep learning-based methods have emerged as the preferred approach for ultrasound data analysis. However, these methods often require large-scale annotated datasets for training deep models, which are not readily available in practical scenarios. Additionally, the presence of speckle noise and other imaging artifacts can introduce numerous hard examples for ultrasound data classification. In this paper, drawing inspiration from self-supervised learning techniques, we present a pre-training method based on mask modeling specifically designed for ultrasound data. Our study investigates three different mask modeling strategies: random masking, vertical masking, and horizontal masking. By employing these strategies, our pre-training approach aims to predict the masked portion of the ultrasound images. Notably, our method does not rely on externally labeled data, allowing us to extract representative features without the need for human annotation. Consequently, we can leverage unlabeled datasets for pre-training. Furthermore, to address the challenges posed by hard samples in ultrasound data, we propose a novel hard sample mining strategy. To evaluate the effectiveness of our proposed method, we conduct experiments on two datasets. The experimental results demonstrate that our approach outperforms other state-of-the-art methods in ultrasound image classification. This indicates the superiority of our pre-training method and its ability to extract discriminative features from ultrasound data, even in the presence of hard examples.

High-Intensity Focused Ultrasound Surgery for Tumor Ablation: A Review of Current Applications

The management of cancer with alternative approaches is a matter of clinical interest worldwide. High-intensity focused ultrasound (HIFU) surgery is a noninvasive technique performed under US or MRI guidance. The most studied therapeutic uses of HIFU involve thermal tissue ablation, demonstrating both palliative and curative potential. However, concurrent mechanical bioeffects also provide opportunities in terms of augmented drug delivery and immunosensitization. The safety and efficacy of HIFU integration with current cancer treatment strategies are being actively investigated in managing primary and secondary tumors, including cancers of the breast, prostate, pancreas, liver, kidney, and bone. Current primary HIFU indications are pain palliation, complete ablation of localized earlystage tumors, or debulking of unresectable late-stage cancers. This review presents the latest HIFU applications, from investigational to clinically approved, in the field of tumor ablation. Keywords: Ultrasound, Ultrasound-High Intensity Focused (HIFU), Interventional-MSK, Interventional-Body, Oncology, Technology Assessment, Tumor Response, MR Imaging © RSNA, 2023.

New trends in non-pharmacological approaches for cardiovascular disease: Therapeutic ultrasound

Significant advances in application of therapeutic ultrasound have been reported in the past decades. Therapeutic ultrasound is an emerging non-invasive stimulation technique. This approach has shown high potential for treatment of various disease including cardiovascular disease. In this review, application principle and significance of the basic parameters of therapeutic ultrasound are summarized. The effects of therapeutic ultrasound in myocardial ischemia, heart failure, myocarditis, arrhythmias, and hypertension are explored, with key focus on the underlying mechanism. Further, the limitations and challenges of ultrasound therapy on clinical translation are evaluated to promote application of the novel strategy in cardiovascular diseases.

The Applications of High-Intensity Focused Ultrasound (HIFU) Ablative Therapy in the Treatment of Primary Breast Cancer: A Systematic Review

BACKGROUND

This study evaluates the role of high-intensity focused ultrasound (HIFU) ablative therapy in treating primary breast cancer.

METHODS

PubMed and Scopus databases were searched according to the PRISMA guidelines to identify studies from 2002 to November 2022. Eligible studies were selected based on criteria such as experimental study type, the use of HIFU therapy as a treatment for localised breast cancer with objective clinical evaluation, i.e., clinical, radiological, and pathological outcomes. Nine studies were included in this study.

RESULTS

Two randomised controlled trials and seven non-randomised clinical trials fulfilled the inclusion criteria. The percentage of patients who achieved complete (100%) coagulation necrosis varied from 17% to 100% across all studies. Eight of the nine studies followed the treat-and-resect protocol in which HIFU-ablated tumours were surgically resected for pathological evaluation. Most breast cancers were single, solitary, and palpable breast tumours. Haematoxylin and eosin stains used for histopathological evaluation showed evidence of coagulation necrosis. Radiological evaluation by MRI showed an absence of contrast enhancement in the HIFU-treated tumour and 1.5 to 2 cm of normal breast tissue, with a thin peripheral rim of enhancement indicative of coagulation necrosis. All studies did not report severe complications, i.e., haemorrhage and infection. Common complications related to HIFU ablation were local mammary oedema, pain, tenderness, and mild to moderate burns. Only one third-degree burn was reported. Generally, the cosmetic outcome was good. The five-year disease-free survival rate was 95%, as reported in two RCTs.

CONCLUSIONS

HIFU ablation can induce tumour coagulation necrosis in localised breast cancer, with a favourable safety profile and cosmetic outcome. However, there is variable evidence of complete coagulation necrosis in the HIFU-treated tumour. Histopathological evidence of coagulation necrosis has been inconsistent, and there is no reliable radiological modality to assess coagulation necrosis confidently. Further exploration is needed to establish the accurate ablation margin with a reliable radiological modality for treatment and follow-up. HIFU therapy is currently limited to single, palpable breast tumours. More extensive and randomised clinical trials are needed to evaluate HIFU therapy for breast cancer, especially where the tumour is left in situ.

Focused ultrasound ablation surgery for multiple breast fibroadenomas: pathological and follow-up results

OBJECTIVE

To investigate the histopathological findings and follow-up outcome of focused ultrasound ablation surgery (FUAS) treatment of multiple fibroadenomas (FA).

METHODS

A total of 20 patients with 101 multiple FAs were enrolled. After one session FUAS ablation, 21 lesions (≥15.0 mm) were surgically removed within one week for histopathological analysis, including 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, H&E staining, nicotinamide adenine dinucleotide (NADH) -flavretin enzyme staining, Transmission electron microscope (TEM) and scanning electron microscope (SEM). The remaining 80 lesions were followed up at 3, 6 and 12 months after treatment.

RESULTS

All ablation procedures were performed successfully. Pathologic findings showed that irreversible damage of FA was confirmed. TTC, H&E and NADH staining and TEM/SEM demonstrated tumor cell death and tumor structural destruction at the gross, cellular, and subcellular levels, respectively. The median shrinkage rate at 12 months post-FUAS was 66.4 (43.6, 89.5) %.

CONCLUSION

Histopathological analysis for FAs after FUAS treatment proved that FUAS could effectively induce irreversible coagulative necrosis of FA, and the tumor volume would gradually shrink in follow-up. FUAS was safe and effective to treat multiple FAs with good cosmesis.Key pointsThis study was the first study of detailed histopathological analysis for FAs after FUAS treatment.FUAS can effectively induce irreversible coagulative necrosis of fibroadenoma cells.FUAS ablation of multiple fibroadenomas is safe and effective.

Feasibility and efficacy of ultrasound-guided high-intensity focused ultrasound of breast fibroadenoma

OBJECTIVE

This nonrandomized prospective clinical trial aimed to assess the efficacy, safety and follow-up outcomes of ultrasound-guided high-intensity focused ultrasound (USgHIFU) surgery in patients with breast fibroadenoma.

METHODS

With the approval of the institutional ethics committee and written informed consent, a total of 113 patients diagnosed with breast fibroadenoma by core-needle biopsy in our hospital were recruited. USgHIFU surgery was performed under local anesthesia. Contrast-enhanced ultrasound (CEUS) or contrast-enhanced MRI (CEMRI) was performed to evaluate the nonperfused volume (NPV). The patients were followed up with physical examination and ultrasound imaging.

RESULTS

The clinical outcome of 85 patients with 147 fibroadenomas with a follow-up time of more than 3 months was analyzed in this study. Fifty-two patients had one lesion, twenty-one patients had two lesions and twelve patients had more than two lesions. During USgHIFU, the median localization time for all fibroadenomas was 3 (interquartile range: 1, 5) min, and the median treatment time was 9 (interquartile range: 5, 15) min. Under local anesthesia, all the patients tolerated the treatment well. No serious epidermal burns were observed in any of the patients. Based on CEUS or CEMRI imaging evaluation, the median NPV ratio was 100% (interquartile range: 79.2%, 116.8%). The VRR were 26.77 ± 50.05%, 50.22 ± 42.01% and 72.74 ± 35.39% at 3-6 months, 6-12 months and >12 months, respectively, which showed significant statistical difference (p < .001).

CONCLUSION

Ultrasound-guided HIFU surgery is an effective and safe noninvasive alternative technique for the treatment of breast fibroadenoma.

Ultrasound radiomics features predicting the dosimetry for focused ultrasound surgery of benign breast tumor: A retrospective study

Purpose: To investigate the correlation between pre-ablation ultrasound radiomics features and the sonication energy for focused ultrasound surgery (FUS) of benign breast tumors.

Method: 53 benign breast tumors of 28 patients treated by ultrasound-guided focused ultrasound surgery (USgFUS) were included in this study. The sonication energy per unit volume of each tumor was calculated. Three-quarter point was chosen as the cut-off to divide the 53 included tumors into high sonication energy (HSE, n = 14) and low sonication energy (LSE, n = 39) groups. For each tumor, the region of interest (ROI) of both the tumor itself (tROI) and the near field tissue (nfROI) were delineated and analyzed separately using ImageJ software. Pearson correlation coefficient and multiple linear regression analysis were used for radiomics feature selection. To explore the diagnostic performance of different ultrasound radiomics features, a receiver operating characteristic (ROC) curve analysis was performed.

Results: In total of 68 radiomics features were extracted from pre-ablation ultrasound images of each tumor. Of all radiomics features, BX in tROI (p < 0.001), BX (p = 0.001) and Circ (p = 0.019) in nfROI were independently predictive features of sonication energy per unit volume. The ROC curves showed that the area under the curve (AUC) values of BX in tROI, BX, and Circ in nfROI were 0.797, 0.787 and 0.822, respectively.

Conclusion: This study provided three radiomics features of pre-ablation ultrasound image as predictors of sonication dose for FUS in benign breast tumors. Further clinical trials are needed to confirm the predictive effect of these radiomics features.

A Few-Shot Learning Approach Assists in the Prognosis Prediction of Magnetic Resonance-Guided Focused Ultrasound for the Local Control of Bone Metastatic Lesions

Simple Summary

We report a local control prediction model for patients undergoing MRgFUS ablation, and provide promising guidance for clinicians to identify a suitable treatment strategy for bone metastatic lesions. We propose a few-shot learning approach to establish the quick prediction of clinical and radiographic responses. On the basis of demographic data, pre-/post-treatment immune-related cytokine change, and MRI imaging, the most suitable parameters were selected to assess potential treatment outcomes during the acute inflammatory stages within 24 h. Traditional logistic regression and few-shot learning models were compared to identify the best model on an independent test. The best predictive few-shot learning model (accuracy of 85.2%, sensitivity of 88.6%, and AUC of 0.95) was achieved by combining the clinical features with the levels of significant cytokines IL-6, IL-13, IP-10, and eotaxin.

Abstract

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) constitutes a noninvasive treatment strategy to ablate deep-seated bone metastases. However, limited evidence suggests that, although cytokines are influenced by thermal necrosis, there is still no cytokine threshold for clinical responses. A prediction model to approximate the postablation immune status on the basis of circulating cytokine activation is thus needed. IL-6 and IP-10, which are proinflammatory cytokines, decreased significantly during the acute phase. Wound-healing cytokines such as VEGF and PDGF increased after ablation, but the increase was not statistically significant. In this phase, IL-6, IL-13, IP-10, and eotaxin expression levels diminished the ongoing inflammatory progression in the treated sites. These cytokine changes also correlated with the response rate of primary tumor control after acute periods. The few-shot learning algorithm was applied to test the correlation between cytokine levels and local control (p = 0.036). The best-fitted model included IL-6, IL-13, IP-10, and eotaxin as cytokine parameters from the few-shot selection, and had an accuracy of 85.2%, sensitivity of 88.6%, and AUC of 0.95. The acceptable usage of this model may help predict the acute-phase prognosis of a patient with painful bone metastasis who underwent local MRgFUS. The application of machine learning in bone metastasis is equivalent or better than the current logistic regression.

Volume reduction for ≥2 cm benign breast lesions after ultrasound-guided microwave ablation with a minimum 12-month follow-up

OBJECTIVE

To prospectively evaluate the efficacy of microwave ablation (MWA) for benign breast lesions (BBLs) ≥2 cm and explore the possible factors associated with the volume reduction rate (VRR) of ablated lesions.

MATERIALS AND METHODS

From November 2013 to December 2017, a total of 80 patients with 104 biopsy-proved BBLs larger than 2 cm in size underwent MWA. After the procedure, patients were followed up via physical and imaging examination consisting of contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI). Possible factors associated with 12-month VRR were assessed, including basic patient characteristics, index lesions and parameters of ablation technique.

RESULTS

The mean tumor size was 2.6 ± 0.6 cm (ranging 2.0-6.3 cm). Of the 104 lesions, 70 were fibroadenomas, 27 adenosis and 7 fibrocystic changes. Post-procedure CEUS or contrast-enhanced MRI showed that all lesions were completely ablated. No immediate or delayed complications were observed. All patients were followed up for more than 12 months (median follow-up 12.5 months). After MWA, the ablated lesion volume decreased significantly by 12 months (p < 0.001), with a mean volume reduction of 80.2 ± 13.1%. Multiple linear regression analysis showed that location adjacent to areola (β = 7.5, 95%CI: 1.0-13.9, p = 0.025) and location adjacent to skin (β = -7.4, 95%CI: -12.7 to -13.9, p = 0.007) were independent factors respectively associated with the increased and decreased 12-month VRR.

CONCLUSION

For BBLs larger than 2 cm, US-guided MWA is a favorable treatment modality, with BBLs adjacent to the areola being associated with more significant 12-month VRR after MWA.

Image-guided Microinvasive Percutaneous Treatment of Breast Lesions: Where Do We Stand?

Treatment of breast lesions has evolved toward the use of less-invasive or minimally invasive techniques. Minimally invasive treatments destroy focal groups of cells without surgery; hence, less anesthesia is required, better cosmetic outcomes are achieved because of minimal (if any) scarring, and recovery times are shorter. These techniques include cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused US, laser therapy, vacuum-assisted excision, and irreversible electroporation. Each modality involves the use of different mechanisms and requires specific considerations for application. To date, only cryoablation and vacuum-assisted excision have received U.S. Food and Drug Administration approval for treatment of fibroadenomas and have been implemented as part of the treatment algorithm by the American Society of Breast Surgeons. Several clinical studies on this topic have been performed on outcomes in patients with breast cancer who were treated with these techniques. The results are promising, with more data for radiofrequency ablation and cryoablation available than for other minimally invasive methods for treatment of early-stage breast cancer. Clinical decisions should be made on a case-by-case basis, according to the availability of the technique. MRI is the most effective imaging modality for postprocedural follow-up, with the pattern of enhancement differentiating residual or recurrent disease from postprocedural changes. ^©RSNA, 2021.

Thermal Ablation as an Alternative for Surgical Resection of Small (≤ 2 cm) Breast Cancers: A Meta-Analysis

Women with early-stage breast cancer have an excellent prognosis with current therapy, but could presumably be treated less invasively, without the need for surgery. The primary goal of this meta-analysis was to examine whether thermal ablation is an effective method to treat early-stage breast cancer. Studies reporting on complete ablation rate after thermal ablation as a treatment of small breast cancers (≤ 2 cm) were included. Methodologic quality of included studies was assessed using MINORS criteria. Complete ablation rates are given as proportions, and meta-regression and subgroup analyses were performed. The overall complete ablation rate in 1266 patients was 86% and was highest after radiofrequency ablation (RFA) (92%). Local recurrence rates varied from 0% to 3%, with a median follow-up of 15 to 61 months. Overall, complication rates were low (5%-18% across techniques) and were highest after high-intensity focused ultrasound ablation and lowest after cryoablation. Cosmetic outcome was good to excellent in at least 85% of patients but was reported infrequently and long-term results of cosmetic outcome after thermal ablation and radiotherapy are still lacking. Thermal ablation techniques treating early-stage breast cancer (≤ 2 cm) are safe and effective based on complete ablation rate and short-term local recurrence rates. Especially, RFA, microwave ablation, and cryoablation are promising techniques as an alternative to surgical resection without jeopardizing current treatment effectiveness or safety. Owing to great heterogeneity in the included studies, a formal recommendation on the best technique is not possible. These findings warrant the design of large randomized controlled trials comparing thermal ablation and breast-conserving surgery in the treatment of T1 breast cancer.

Applications of High-Intensity Focused Ultrasound in the Treatment of Different Pathologies

Objective:

The purpose of this literature search was to review the benefits of high-intensity focused ultrasound (HIFU) and its application for different pathologies.

Methods:

This review summarizes the implementation of HIFU for different pathologic conditions. An National Center for Biotechnology Information, PubMed, MEDLINE, Medscape, and Google Scholar database search (1992–2016) was done with the following keywords: high-intensity focused ultrasound; uses of HIFU; and applications of HIFU in the liver, bones, uterine fibroids, prostate, breast, thyroid, pancreas, kidneys, brain, urinary bladder, and so on. Tables and graphs were created for all the variables included in the study, and descriptive statistics were applied.

Results:

In total, 110 records were identified, through database search. In addition, 20 articles were identified through other sources. Screening of the articles was performed, and 20 were removed due to duplication; further screening was performed for 110 articles, and 30 records were further excluded. Full-text articles were assessed for eligibility and 30 were retained. Full-text articles were excluded (N = 36) on the basis that research was performed on animals, and this review article was performed solely for human application. There were 42 qualitative syntheses that researches added to the review. In addition, 42 quantitative synthesis (meta-analysis) were added to the review.

Conclusion:

The conclusion of this narrative review indicates that HIFU is noninvasive, nonharmful, and effective in treating diseases and tumors of the brain, breast, bone, hepatic, renal, pancreas, and prostate; uterine fibroids; and many other solid tumors. Recent technological development suggests that HIFU is likely to play a significant role in future surgical practices. Further research works should be conducted on a large sample size to obtain more accurate results in the application of HIFU.

A Novel High-Intensity Focused Ultrasound-Treated Herpes Simplex Virus 2 Vaccine Induces Long-Term Protective Immunity against Lethal Challenge in Mice

High-intensity focused ultrasound (HIFU), a noninvasive ablation therapy that has been widely used clinically in ablation of solid tumors, induces immune sensitization. We therefore in this study investigated whether HIFU treatment could enhance the efficacy of a herpes simplex virus 2 (HSV-2) vaccine. First, we observed that in HSV-2-positive cervical intraepithelial neoplasia (CIN) II patients, HIFU treatment induced significantly higher anti-HSV-2 neutralization response than surgical removal. Next, we tested the efficacy of HIFU-treated, UV-inactivated HSV-2-infected cells as a proof-of-concept vaccine in mice. Our data showed that HIFU-treated formulation significantly enhanced HSV-2 antibody titers and neutralization titers, compared to UV-, microwave (MW)-, or freeze-thaw (FT)-treated formulations. HIFU treatment also promoted the Th1/2 cell-mediated response. A long-term full protection was observed in mice that received the HIFU-treated formulation, and no weight loss was detected. Our findings indicate that the novel application of HIFU in vaccine production may represent a rational way to improve vaccine efficacy.IMPORTANCE High-intensity focused ultrasound (HIFU) is mainly used in tumor ablation and tumor vaccinology study. It has been shown to induce immune sensitization and enhance tumor responsiveness to other therapies. Our study has shown enhanced anti-HSV-2 response in HIFU-treated CIN II patients. Furthermore, in a murine model, we have demonstrated that HIFU-treated HSV-2 vaccine induced long-term protective immunity against lethal challenge. Our findings indicate that the novel application of HIFU in vaccine production may represent a rational way to improve vaccine efficacy.

Breast fibroadenomas: a review in the light of current literature

&lt;br&gt;&lt;b&gt;Introduction:&lt;/b&gt; Fibroadenomas are one of the most common benign tumors of the breast in the adolescent females accounting for about 2/3&lt;sup&gt;rd&lt;/sup&gt; of all the breast lumps and more than half of all the biopsied breast lesions. They come into being due to overgrowth of glandular tissue under the influence of hormonal changes that the girls undergo at the time of puberty. Due to the wide prevalence of fibroadenomas and the psychosocial morbidity associated with the finding of a breast mass, it is imperative for physicians treating adolescent patients to be thoroughly familiar and updated with this disease. &lt;br&gt;&lt;b&gt;Aim:&lt;/b&gt; The article aims at providing a brief review of the classification, presentation, diagnosis, and update on the management of breast fibroadenomas on the basis of recent literature.

Acoustic Coupling Quantification in Ultrasound-Guided Focused Ultrasound Surgery: Simulation-Based Evaluation and Experimental Feasibility Study

Adequate acoustic coupling between the therapeutic transducer and the patient's body is essential for safe and efficient focused ultrasound surgery (FUS). There is currently no quantitative method for acoustic coupling verification in ultrasound-guided FUS. In this work, a quantitative method was developed and a related metric was introduced: the acoustic coupling coefficient. This metric associates the adequacy of the acoustic coupling with the reflected signals recorded through an imaging probe during a low-energy sonication. The acoustic coupling issue was simulated in silico and validated through in vitro tests. Our results indicated a sigmoidal behavior of the introduced metric as the contact surface between the coupling system and the patient's skin increases. The proposed method could be a safety-check criterion for verifying the adequacy of the acoustic coupling before starting the FUS treatment, thus ensuring efficient energy transmission to the target and preventing damage to both the patient and the instrumentation.

High-Intensity Focused Ultrasound: A Satisfactory Noninvasive Procedure for Neck Rejuvenation

BACKGROUND

High-intensity focused ultrasound (HIFU) is an advanced technology that has been developed in response to the growing demand for noninvasive face rejuvenation.

OBJECTIVES

The aim of this study was to evaluate the rejuvenation effects, patient satisfaction, and safety of HIFU treatment of the neck in a European population.

METHODS

This was a prospective study of 20 patients. The patients were treated with HIFU, and the outcomes were investigated. The modified FACE-Objective Assessment Scale, developed by our team, and the subjective Investigator Global Improvement Assessment Scale (IGIAS; -1 to 3) were used to judge the results of HIFU. Five blinded evaluators scored the procedure outcomes based on photographs taken before and 6 months after the procedure. Side effects were reported and pain was evaluated on a visual analog scale of 0 to 10.

RESULTS

Clinical results, such as better definition of the cervicomental angle, were observed in the treated areas. The pretreatment and posttreatment evaluation scores for double chin and skin laxity were evaluated by 4 of 5 evaluators as significantly improved. The IGIAS score was between 1 and 5 in 2 patients, between 6 and 10 in 7 patients, and between 11 and 15 in 11 patients. No patients had a score between -5 and 0. No major complications were reported. The mean pain scores for the D4, M7, and S7 transducer treatments were 5.6 (range, 4.5-6.7), 4.2 (range, 2.5-5.9), and 2.05 (range, 1.05-3.05), respectively.

CONCLUSIONS

HIFU may be considered a satisfactory, simple, reproducible, rapid, and safe procedure for neck rejuvenation.

Level of Evidence: 4.

A Pilot Study for a Quantitative Evaluation of Acoustic Coupling in US-guided Focused Ultrasound Surgery

In Ultrasound-guided High Intensity Focused Ultrasound (USgHIFU) surgery, the verification of the acoustic coupling correctness between the HIFU transducer and the patient's body is a fundamental step for an efficient and safe therapy. Nowadays, clinicians perform this check by qualitative inspecting Ultrasound images. The aim of this study is the introduction of an objective index to quantitively evaluate the coupling on the base of the radiofrequency echo signals acquired during a low-energy HIFU shot. The experimental session involved a tissue mimicking phantom and a robotic system composed by a HIFU therapeutic transducer and a 2D confocal Ultrasound probe. 15 different coupling conditions between the phantom and the transducer were tested: in each of them, the maximum absolute value of the Fourier Transform of the echo signals was computed and employed to determine an Acoustic Coupling (AC) coefficient.This metrics showed a sigmoidal trend between AC coefficient and coupling increase. This curve can be employed as a calibration tool to quantitatively assess the correctness of the therapeutic set-up before starting the HIFU treatment.

HIFU for Bone Metastases and other Musculoskeletal Applications

High-intensity focused ultrasound (HIFU) is a totally noninvasive procedure that has shown promising results in the management of numerous malignant and nonmalignant conditions. Under magnetic resonance or ultrasound guidance, high-intensity ultrasound waves are focused on a small, well-defined target region, inducing biologic tissue heating and coagulative necrosis, thus resulting in a precise and localized ablation. This treatment has shown both great safety and efficacy profiles, and may offer a multimodal approach to different diseases, providing pain palliation, potential local tumor control, and, in some cases, remineralization of trabecular bone. In musculoskeletal field, HIFU received FDA approval for treating bone metastasis, but its application has also been extended to other conditions, such as osteoid osteoma, desmoid tumor, low-flow vascular malformation, and facet joint osteoarthritis. This article illustrates the basic principles of HIFU and its main effects on biologic tissues with particular attention on bone, provides a step-by-step description of the HIFU procedure, and discusses the commonly treated conditions, in particular bone metastases.

[Treatment of fibroadenomas by high-intensity focused ultrasound: What results? Review]

OBJECTIVES

To assess benefits and adverse effects of high-intensity focused ultrasound (HIFU) as a treatment for fibroadenomas (FA).

METHODS

To ensure the quality of the methodology, the PRISMA criteria have been met at all stages of the development of this review. We searched MEDLINE from inception to May 2017, without any restriction.

KEYWORDS

fibroadenoma, focused ultrasound, HIFU and fibroadenomata were used. Data were extracted and the results were compared. Two reviewers independently extracted study characteristics and outcome data.

RESULTS

Of 20 identified abstracts, 5 primary studies met inclusion criteria. All studies reported a reduction in the size of FA treated with an increasing effect over time. Pain tolerance was most often assessed as moderate. Adverse effects of HIFU were not severe in all studies.

CONCLUSIONS

HIFU appears to be a promising technique in the treatment of fibroadenomas with a volume decrease of approximately 50 % at 6 months of therapy.

High-intensity focused ultrasound in the treatment of breast tumours

High-intensity focused ultrasound (HIFU) is a minimally invasive technique that has been used for the treatment of both benign and malignant tumours. With HIFU, an ultrasound (US) beam propagates through soft tissue as a high-frequency pressure wave. The US beam is focused at a small target volume, and due to the energy building up at this site, the temperature rises, causing coagulative necrosis and protein denaturation within a few seconds. HIFU is capable of providing a completely non-invasive treatment without causing damage to the directly adjacent tissues. HIFU can be either guided by US or magnetic resonance imaging (MRI). Guided imaging is used to plan the treatment, detect any movement during the treatment and monitor response in real-time. This review describes the history of HIFU, the HIFU technique, available devices and gives an overview of the published literature in the treatment of benign and malignant breast tumours with HIFU.

High-intensity focused ultrasound in the treatment of breast fibroadenomata (HIFU-F trial)

BACKGROUND

High-intensity focussed ultrasound (HIFU) is a non-invasive ablative technique utilising the application of high frequency ultrasound (US) pressure waves to cause tissue necrosis. This emerging technology is currently limited by prolonged treatment times. The aim of the HIFU-F trial was to perform circumferential HIFU treatment as a means of shortening treatment times.

METHODS

A prospective trial was set up to treat 50 consecutive patients ≥18 years of age. Eligible patients possessed symptomatic fibroadenomata, visible on US. Patients ≥25 years of age required histological confirmation of the diagnosis. Primary outcome measures were reduction in treatment time, reduction in volume on US after 12 months and complication rates.

RESULTS

HIFU treatment was performed in 51 patients (53 treatments) with a mean age of 29.8 years (SD 7.2 years) and a diameter of 2.6 cm (SD 1.4 cm). Circumferential ablation reduced treatment times by an estimated 19.9 min (SD 25.1 min), which is a 29.4% (SD 15.2%) reduction compared with whole lesion ablation. Volume reduction of 43.2% (SD 35.4%; p < 0.005, paired t-test) was observed on US at 12 months post-treatment. Local complications completely resolved at 1 month apart from skin hyper-pigmentation, which persisted in nine cases at three months, six cases at 6 months and six at 12 months.

CONCLUSION

Circumferential HIFU treatment for breast fibroadenomata is feasible to reduce both lesion size and treatment time. HIFU is a non-invasive alternative technique for the treatment of breast fibroadenomata. ISRCTN registration: 76622747.

Ultrasound guided percutaneous microwave ablation of benign breast lesions

The benign breast lesions (BBLs) share a high incidence for women and therapy methods with minimal invasion and better cosmetic outcome are thirsted for. In this study, 122 patients with 198 biopsy-proved BBLs were enrolled. Ultrasound (US)-guided microwave ablation (MWA) was performed with local anesthesia from November, 2013 to April, 2016. The mean longest tumor size assessed was 1.6±0.7 cm (ranging 0.7-4.9 cm). MWA was successfully performed in all cases including 85 lesions adjacent to the skin, pectoralis and areola. The mean ablation time was 3.2mins (ranging 0.5-18.3 mins). 99.5% of BBLs showed complete ablation when assessed by magnetic resonance imaging and 100% of them by US. At the median 14-month follow-up, the BBLs were not palpable in 45.9 % of the cases (palpable in 90.2 % of the cases before MWA) and the mean volume reduction ratio was 78.4±33.5% for total lesions and 89.3±20.8%, 84.7±27.6% and 55.9±32.9% for ≤1.0 cm, 1.1-2.0cm and >2.0 cm lesions in 12-month follow-up, respectively. Cosmesis were reported as good or excellent in 100 % by physician and patients. No side effect was found. The MWA of the BBLs proved feasible and effective, while showing meaningful reduction in volume, palpability and cosmetic satisfying outcomes.

Magnetic Resonance Imaging-Guided Focused Ultrasound Surgery for the Treatment of Symptomatic Uterine Fibroids

Uterine fibroids, the most common benign tumor in women of childbearing age, may cause symptoms including pelvic pain, menorrhagia, dysmenorrhea, pressure, urinary symptoms, and infertility. Various approaches are available to treat symptomatic uterine fibroids. Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) represents a recently introduced noninvasive safe and effective technique that can be performed without general anesthesia, in an outpatient setting. We review the principles of MRgFUS, describing patient selection criteria for the treatments performed at our center and we present a series of five selected patients with symptomatic uterine fibroids treated with this not yet widely known technique, showing its efficacy in symptom improvement and fibroid volume reduction.

Long-term efficacy of ultrasound-guided high-intensity focused ultrasound treatment of breast fibroadenoma

BACKGROUND

To assess the long term efficacy and tolerability of one or two ultrasound (US)-guided high-intensity focused ultrasound (HIFU) treatment in patients with breast fibroadenoma (FA).

METHODS

Twenty patients with 26 FA were selected for US-guided HIFU. The therapy was performed in one or two sessions. FA volume was assessed before and followed up to 24 months after the last HIFU. After each treatment, adverse events were evaluated.

RESULTS

In 19/26 FA (73.1%) one HIFU was performed (group 1), whereas 7/26 FA (26.9%) received second HIFU (group 2) 6-9 months (median, 7 months) after the first session. In group 1 and 2, FA volume decreased significantly at 1-month (p < 0.001) and 3-month follow-up (p = 0.005), respectively, and continued to reduce until 24-month follow-up (p < 0.001 and p = 0.003, respectively). At 24 months, mean volume reduction was 77.32% in group 1 and 90.47% in group 2 (p = 0.025). Mild subcutaneous edema was observed in 4 patients and skin erythema in 3 patients.

CONCLUSIONS

US-guided HIFU represents a promising non-invasive method with sustainable FA volume reduction and patient's tolerability. Although one treatment is highly efficient, the volume reduction can be increased with second treatment.

TRIAL REGISTRATION

NCT01331954. Registered 07 April 2011.

Technical success, technique efficacy and complications of minimally-invasive imaging-guided percutaneous ablation procedures of breast cancer: A systematic review and meta-analysis

OBJECTIVES

To systematically review studies concerning imaging-guided minimally-invasive breast cancer treatments.

METHODS

An online database search was performed for English-language articles evaluating percutaneous breast cancer ablation. Pooled data and 95% confidence intervals (CIs) were calculated. Technical success, technique efficacy, minor and major complications were analysed, including ablation technique subgroup analysis and effect of tumour size on outcome.

RESULTS

Forty-five studies were analysed, including 1,156 patients and 1,168 lesions. Radiofrequency (n=577; 50%), microwaves (n=78; 7%), laser (n=227; 19%), cryoablation (n=156; 13%) and high-intensity focused ultrasound (HIFU, n=129; 11%) were used. Pooled technical success was 96% (95%CI 94-97%) [laser=98% (95-99%); HIFU=96% (90-98%); radiofrequency=96% (93-97%); cryoablation=95% (90-98%); microwave=93% (81-98%)]. Pooled technique efficacy was 75% (67-81%) [radiofrequency=82% (74-88); cryoablation=75% (51-90); laser=59% (35-79); HIFU=49% (26-74)]. Major complications pooled rate was 6% (4-8). Minor complications pooled rate was 8% (5-13%). Differences between techniques were not significant for technical success (p=0.449), major complications (p=0.181) or minor complications (p=0.762), but significant for technique efficacy (p=0.009). Tumour size did not impact on variables (p>0.142).

CONCLUSIONS

Imaging-guided percutaneous ablation techniques of breast cancer have a high rate of technical success, while technique efficacy remains suboptimal. Complication rates are relatively low.

KEY POINTS

• Imaging-guided ablation techniques for breast cancer are 96% technically successful. • Overall technique efficacy rate is 75% but largely inhomogeneous among studies. • Overall major and minor complication rates are low (6-8%).

Minimally invasive ablative techniques in the treatment of breast cancer: a systematic review and meta-analysis

PURPOSE

Breast-conserving surgery is effective for breast cancer treatment but is associated with morbidity in particular high re-excision rates. We performed a systematic review and meta-analysis to assess the current evidence for clinical outcomes with minimally invasive ablative techniques in the non-surgical treatment of breast cancer.

METHODS

A systematic search of the literature was performed using PubMed and Medline library databases to identify all studies published between 1994 and May 2016. Studies were considered eligible for inclusion if they evaluated the role of ablative techniques in the treatment of breast cancer and included ten patients or more. Studies that failed to fulfil the inclusion criteria were excluded.

RESULTS

We identified 63 studies including 1608 patients whose breast tumours were treated with radiofrequency (RFA), high intensity focussed ultrasound (HIFU), cryo-, laser or microwave ablation. Fifty studies reported on the number of patients with complete ablation as found on histopathology and the highest rate of complete ablation was achieved with RFA (87.1%, 491/564) and microwave ablation (83.2%, 89/107). Short-term complications were most often reported with microwave ablation (14.6%, 21/144). Recurrence was reported in 24 patients (4.2%, 24/570) and most often with laser ablation (10.7%, 11/103). The shortest treatment times were observed with RFA (15.6 ± 5.6 min) and the longest with HIFU (101.5 ± 46.6 min).

CONCLUSION

Minimally invasive ablative techniques are able to successfully induce coagulative necrosis in breast cancer with a low side effect profile. Adequately powered and prospectively conducted cohort trials are required to confirm complete pathological ablation in all patients.

High intensity focused ultrasound (HIFU) applied to hepato-bilio-pancreatic and the digestive system-current state of the art and future perspectives

BACKGROUND

High intensity focused ultrasound (HIFU) is emerging as a valid minimally-invasive image-guided treatment of malignancies. We aimed to review to current state of the art of HIFU therapy applied to the digestive system and discuss some promising avenues of the technology.

METHODS

Pertinent studies were identified through PubMed and Embase search engines using the following keywords, combined in different ways: HIFU, esophagus, stomach, liver, pancreas, gallbladder, colon, rectum, and cancer. Experimental proof of the concept of endoluminal HIFU mucosa/submucosa ablation using a custom-made transducer has been obtained in vivo in the porcine model.

RESULTS

Forty-four studies reported on the clinical use of HIFU to treat liver lesions, while 19 series were found on HIFU treatment of pancreatic cancers and four studies included patients suffering from both liver and pancreatic cancers, reporting on a total of 1,682 and 823 cases for liver and pancreas, respectively. Only very limited comparative prospective studies have been reported.

CONCLUSIONS

Digestive system clinical applications of HIFU are limited to pancreatic and liver cancer. It is safe and well tolerated. The exact place in the hepatocellular carcinoma (HCC) management algorithm remains to be defined. HIFU seems to add clear survival advantages over trans arterial chemo embolization (TACE) alone and similar results when compared to radio frequency (RF). For pancreatic cancer, HIFU achieves consistent cancer-related pain relief. Further research is warranted to improve targeting accuracy and efficacy monitoring. Furthermore, additional work is required to transfer this technology on appealing treatments such as endoscopic HIFU-based therapies.

Comparison of the synergistic effect of lipid nanobubbles and SonoVue microbubbles for high intensity focused ultrasound thermal ablation of tumors

Microbubbles (MBs) are considered as an important enhancer for high intensity focused ultrasound (HIFU) treatment of benign or malignant tumors. Recently, different sizes of gas-filled bubbles have been investigated to improve the therapeutic efficiency of HIFU thermal ablation and reduce side effects associated with ultrasound power and irradiation time. However, nanobubbles (NBs) as an ultrasound contrast agent for synergistic therapy of HIFU thermal ablation remain controversial due to their small nano-size in diameter. In this study, phospholipid-shell and gas-core NBs with a narrow size range of 500–600 nm were developed. The synergistic effect of NBs for HIFU thermal ablation was carefully studied both in excised bovine livers and in breast tumor models of rabbits, and made a critical comparison with that of commercial SonoVue microbubbles (SonoVue MBs). In addition, the pathological changes of the targeted area in tumor tissue after HIFU ablation were further investigated. Phosphate buffer saline (PBS) was used as the control. Under the same HIFU parameters, the quantitative echo intensity of B-mode ultrasound image and the volume of coagulative necrosis in lipid NBs groups were significantly higher and larger than that in PBS groups, but could not be demonstrated a difference to that in SonoVue MBs groups both ex vivo and in vivo. These results showed that the synergistic effect of lipid NBs for HIFU thermal ablation were similar with that of SonoVue MBs, and further indicate that lipid NBs could potentially become an enhancer for HIFU thermal ablation of tumors.

A review of ablative techniques in the treatment of breast fibroadenomata

Introduction

Breast fibroadenomata (FAD) are benign lesions which occur in about 10 % of all women. Diagnosis is made by triple assessment (physical examination, imaging and/or histopathology/cytology). For a definitive diagnosis of FAD, the treatment is conservative unless the patient is symptomatic. For symptomatic patients, the lumps can be surgically excised or removed interventionally by vacuum-assisted mammotomy (VAM). Ablative techniques like high-intensity focused ultrasound (HIFU), cryo-ablation and laser ablation have also been used for the treatment of FAD, providing a minimally invasive treatment without scarring or poor cosmesis. This review summarises current trials using minimally invasive ablative techniques in the treatment of breast FAD.

Methods

A comprehensive review of studies using minimally invasive ablative techniques was performed.

Results

There are currently several trials completed or recruiting patients using HIFU, cryo-ablation and laser ablation in the treatment of breast FAD. The results look very promising but cannot be compared at this point due to heterogeneity between studies.

Conclusion

Minimally invasive ablative techniques like HIFU, cryo-ablation and laser ablation are promising in the treatment of breast FAD. Future trials should be randomised and contain larger numbers of patients to determine the effectiveness of ablative techniques with more precision.

MRI-guided focused ultrasound surgery in musculoskeletal diseases: the hot topics

MRI-guided focused ultrasound surgery (MRgFUS) is a minimally invasive treatment guided by the most sophisticated imaging tool available in today's clinical practice. Both the imaging and therapeutic sides of the equipment are based on non-ionizing energy. This technique is a very promising option as potential treatment for several pathologies, including musculoskeletal (MSK) disorders. Apart from clinical applications, MRgFUS technology is the result of long, heavy and cumulative efforts exploring the effects of ultrasound on biological tissues and function, the generation of focused ultrasound and treatment monitoring by MRI. The aim of this article is to give an updated overview on a "new" interventional technique and on its applications for MSK and allied sciences.

Magnetic Hyperthermia Ablation of Tumors Using Injectable Fe₃O₄/Calcium Phosphate Cement

In this work, we have developed an injectable and biodegradable material using CPC containing Fe3O4 nanoparticles for minimally invasive and efficiently magnetic hyperthermia ablation of tumors. When exposed to an alternating magnetic field, the MCPC could quickly generate heat. The temperature of PBS and the excised bovine liver increased with the MCPC weight, iron content, and time. The ablated liver tissue volume for 0.36 g of 10% MCPC was 0.2 ± 0.03, 1.01 ± 0.07, and 1.96 ± 0.19 cm(3), respectively, at the time point of 60, 180, and 300 s. In our in vivo experiment, the MCPC could be directly injected into the center of the tumors under the guidance of ultrasound imaging. The formed MCPC was well-restricted within the tumor tissues without leakage, and the tumors were completely ablated by 0.36 g of 10% injectable MCPC after 180 s of induction heating.