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.

Cryoablation for the Treatment of Breast Cancer: A Review of the Current Landscape and Future Possibilities

Breast cancer is one of the most common malignancies worldwide. Traditional treatment options for breast cancer include surgery, radiation therapy, and chemotherapy. However, cryoablation, a minimally invasive technique, has emerged as a promising alternative for the treatment of early-stage breast cancer. This article aims to provide an overview of cryoablation, focusing on incorporation into practice, patient selection, procedural technique, imaging follow-up, post-treatment radiopathological findings, and current and ongoing research in the field. The current evidence suggests that cryoablation offers a safe and effective treatment option for selected patients, providing comparable oncological outcomes to traditional treatments while minimizing invasiveness and preserving breast aesthetics.

Cryoablation Therapy for Early-Stage Breast Cancer: Evidence and Rationale

Recent advances in breast cancer research and treatment propel a paradigm shift toward less aggressive and less invasive treatment for some early-stage breast cancer. Select patients with small, low-risk tumors may benefit from a less aggressive approach with de-escalated local therapy. Cryoablation of breast cancer is an emerging nonsurgical treatment alternative to breast-conserving surgery. Advantages of cryoablation over surgery include the use of local anesthesia, faster recovery, improved cosmesis, and cost savings. Proper patient selection and meticulous technique are keys to achieving successful clinical outcomes. The best candidates for cryoablation have unifocal invasive ductal carcinoma tumors that are low grade, hormone receptor positive, and ≤1.5 cm in size. In this review, we outline the current evidence, patient selection criteria, procedural technique, pre- and postablation imaging, and the advantages and limitations of cryoablation therapy.

Leveraging cryoablation and checkpoint inhibitors for high-risk triple negative breast cancer

Breast cancer is the second most common cancer among women in the United States in which the standard of care treatment is surgery with adjunctive therapy. Cryoablation, which destroys the tumor using extremely cold temperatures while preserving the potential tumor antigens, is a promising alternative to surgical resection. It is less invasive, cosmetically appeasing, cost-effective, and capable of contributing to the abscopal effect - the immune response targeting potential distant metastasis. However, to maximize the immunologic benefit of cryoablation in biologically high-risk breast cancers, combination with therapies that enhance immune activation, such as immune checkpoint inhibitors (ICIs) may be necessary. This mini review describes the fundamentals of cryoablation and treatment with ICIs, as well as discuss the caveats in both strategies and current clinical trials aimed to improve this approach to benefit patients.

Heat treatment-induced autophagy promotes breast cancer cell invasion and metastasis via TGF-β2-mediated epithelial-mesenchymal transitions

Background

Insufficient thermal ablation can accelerate malignant behaviors and metastases in some solid tumors, and epithelial-mesenchymal transition (EMT) and autophagy are involved in tumor metastasis. It has been found that TGF-β2 which belongs to the family of transforming growth factors often associated with cancer cell invasiveness and EMT. However, whether the interactions between autophagy and TGF-β2 induce EMT in breast cancer (BC) cells following insufficient microwave ablation (MWA) remains unclear.

Methods

BC cells were treated with sublethal heat treatment to simulate insufficient MWA, and the effects of heat treatment on the BC cell phenotypes were explored. CCK-8, colony formation, flow cytometry, Transwell, and wound healing assays were performed to evaluate the influence of sublethal heat treatment on the proliferation, apoptosis, invasion, and migration of BC cells. Western blotting, real-time quantitative PCR, immunofluorescence, and transmission electron microscopy were carried out to determine the changes in markers associated with autophagy and EMT following sublethal heat treatment.

Results

Results showed that heat treatment promoted the proliferation of surviving BC cells, which was accompanied by autophagy induction. Heat treatment-induced autophagy up-regulated TGF-β2/Smad2 signaling and promoted EMT phenotype, thereby enhancing BC cells' migration and invasion abilities. An increase or decrease of TGF-β2 expression resulted in the potentiation and suppression of autophagy, as well as the enhancement and abatement of EMT. Autophagy inhibitors facilitated apoptosis and repressed proliferation of BC cells in vitro, and thwarted BC cell tumor growth and pulmonary metastasis in vivo.

Conclusion

Heat treatment-induced autophagy promoted invasion and metastasis via TGF-β2/Smad2-mediated EMTs. Suppressing autophagy may be a suitable strategy for overcoming the progression and metastasis of residual BC cells following insufficient MWA.

Microwave ablation without subsequent lumpectomy versus breast-conserving surgery for early breast cancer: a propensity score matching study

PURPOSE

To compare the efficacy of ultrasound-guided percutaneous microwave ablation (MWA) without subsequent lumpectomy and breast-conserving surgery (BCS) in patients with early breast cancer (BC).

MATERIALS AND METHODS

This retrospective cohort study enrolled 106 patients with early BC (T_0/1/2 N_0/1 M₀) treated by MWA (n = 21) or BCS (n = 85) from October 2014 to December 2020. Propensity score matching (PSM) was performed to balance the baseline characteristics between MWA and BCS groups. The tumor progression, overall survival (OS), disease-specific survival (DSS), complications, and cosmetic results were compared.

RESULTS

After PSM, there were 21 patients with balanced baseline characteristics in each group. After a median follow-up of 43 months (range, 15-89 months), there was no significant difference in tumor progression (10% vs 2%, p = 0.18), OS (96% vs 99%, p = 0.36), DSS (100% vs 99%, p > 0.99), and complications (0% vs 19%, p = 0.58). The operation time of MWA was shorter (60 min vs 101 min, p < 0.001) than that of BCS. For the management of metastatic lymph nodes, five (5/21, 24%) patients with six metastatic nodes underwent ablation in the MWA group and three patients (3/21, 14%) with six metastatic nodes underwent axillary lymph node dissection in the BCS group. All the patients in the MWA group reported excellent cosmetic results, but 29% of BCS patients expressed dissatisfaction with breast asymmetry (10%) and scar formation (19%) (p < 0.001).

CONCLUSION

This pilot study indicated that in selected early BC patients, microwave ablation without subsequent lumpectomy had comparable tumor control effect with breast-conserving surgery and better cosmetic results at an intermediate follow-up.HighlightsMWA without subsequent lumpectomy has a comparable interim survival effect and better cosmetic results as BCS in the treatment of selected early breast cancer.MWA has the potential to be a viable and promising therapeutic option for breast cancer patients reluctant or intolerant to surgery with the advantage of minimal invasion.

Ablative Therapies for Breast Cancer: State of Art

Breast cancer (BC) is the most frequently diagnosed malignancy among women. In the past two decades, new technologies and BC screening have led to the diagnosis of smaller and earlier-stage BC (ESBC). Therefore, percutaneous minimally invasive techniques (PMIT) were adopted to treat patients unfit for surgery, women who refuse it, or elderly patients with comorbidities that could make surgery a difficult and life-threatening treatment. The target of PMIT is small-size ESBC with the scope of obtaining similar efficacy as surgery. Minimally invasive treatments are convenient alternatives with promising effectiveness, lower morbidity, less cost, less scarring and pain, and more satisfying cosmetic results. Ablative techniques used in BC are cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused ultrasound (US), and laser ablation. The aim of our study is to discuss the current status of percutaneous management of BC, evaluate the clinical outcomes of PMIT in BC, and analyze future perspectives regarding ablation therapy in BC.

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.

Ultrasound-guided microwave ablation for multiple benign breast lesions: A prospective study

AIM

To provide medical evidence for the feasibility and clinical efficacy of microwave ablation (MWA) in the treatment of benign breast lesions, especially multiple benign breast lesions.

METHODS

We included patients with multiple benign breast lesions who were seen at our hospital during the period from June 2016 to December 2017. After signed informed consent had been obtained and core breast biopsy, all included patients who underwent MWA at 2450 MHz with 30 W power adjustment. Postoperative follow-up was performed for 1 year, at 3-month intervals. Ablation time, complications, volume-reduction ratio (VRR), and lesion residuals after ablation were analyzed.

RESULTS

We ultimately included 1274 lesions from 164 cases in the study with a median follow-up time of 13.6 months. For a single lesion, the median ablation time was 36 s. Pain, fat liquefaction, and skin scalding were the most common complications. The overall complete disappearance rate was 92.1% (1173/1274), with the highest complete disappearance rate observed among those patients with lesions <10 mm in diameter (942/968, 97.3%). For lesions that persisted at 12 months after MWA, the average the volume-reduction ratio (VRR) was 87.5%.

CONCLUSIONS

For multiple benign lesions of the breast, especially lesions with the longest diameter <10 mm, ultrasound guided MWA is a minimally invasive, relatively quick therapeutic strategy associated with accuracy in treatment and few complications.

Ultrasound-Guided Laser Ablation After Excisional Vacuum-Assisted Breast Biopsy for Small Malignant Breast Lesions: Preliminary Results

Background:

The purpose of this preliminary study is to evaluate the feasibility of the excisional ultrasound (US) guided vacuum-assisted breast biopsy (VAE), followed by US-guided Laser Interstitial Thermal Therapy (LITT) in the treatment of unifocal ductal breast carcinomas ≤ 1 cm and estimate the ablation rate analyzing the final histopathological results after subsequent surgical excision.

Methods:

In a single session 11 female patients with unifocal less than a centimeter breast cancer underwent 2 different minimally invasive percutaneous US-guided techniques: a VAE breast biopsy with an 8 G needle to remove the lesion and, immediately after, a LITT ablation in the biopsy site. Four weeks later, all patients underwent radiological follow-up. Afterward, a systematic surgery was performed, the ablation rate was calculated, and iconographic and histological features were correlated.

Results:

Average maximum diameter of the lesions was 7.6 mm (5-10 mm). No patient reported pain or discomfort during procedure. 1/11 patient (9.1%) reported an early minor complication (a small superficial skin burn). After surgical excision, the histopathological evaluation reported in 10/11 cases (90.9%) complete ablation of the target lesion. In only one case (9.1%) residual cancer was detected. The necrotic-hemorrhagic cavities showed a mean maximum diameter of 27.3 mm (20-35 mm).

Conclusions:

Laser ablation performed after excisional biopsy could be considered a valid alternative to surgical excision for the treatment of lesions ≤ 1 cm, if carried out by expert radiologists. The association of these minimally invasive percutaneous methods has proven to be reliable, fast, and safe with an ablation rate of 90.9% and excellent aesthetic results. RM and CESM are potentially able to quantifying treatment results and to follow-up the ablation effects.

Hydrodissection - Practical applications in ultrasound-guided breast interventions

Hydrodissection is a procedural tactic utilized in various interventions. It is a technique which helps separate structures in order to safely perform a certain procedure. This article will provide a review of hydrodissection, how to perform this technique, and why it can be useful in breast interventions.

Microwave Ablation Versus Nipple Sparing Mastectomy for Breast Cancer ≤5 cm: A Pilot Cohort Study

Objectives

Compared with nipple sparing mastectomy (NSM), microwave ablation (MWA) is one relatively new modality indicated for selected breast cancer with nipple sparing and with little of evidence-based medical research for decision-making. The objective of this study was to compare the effect of ultrasound-guided percutaneous MWA and NSM for breast cancer.

Materials and Methods

A retrospective cohort study was conducted in a single institution from 2014 to 2020. Women with invasive ductal carcinoma of the breast ≤ 5cm treated by MWA or NSM were enrolled. The primary end point was tumor progression and secondary end points included survival, cosmetic results, and complications.

Results

21 patients in the MWA group and 43 in the NSM group were evaluated. The mean tumor size was 2.3 cm (range, 0.3-5.0 cm). Median follow-up was 26.7 months (range, 14.6-62.5 months). The mean age of MWA was 24 years older than that of the NSM group. All the patients achieved technique effectiveness. One local tumor progression and one ipsilateral breast recurrence occurred at 42 and 28 months after MWA, respectively. One ipsilateral breast recurrence and two bone metastasis occurred at 31.2, 34, and 30.5 months after NSM. Two groups had no significant difference in tumor progression (P = 0.16). No participants in both groups developed cancer related death (P > 0.99) and major complications (P > 0.99). However, MWA needed less hospitalization time (P < 0.001) and achieved better cosmetic results (P < 0.001).

Conclusions

MWA achieved similar short term effect for breast cancer control and better cosmetic satisfaction compared with NSM in selected patients. MWA provides appropriate option for elderly patients who are unfit for surgery.

Cryoablation In The Management Of Breast Cancer: Evidence To Date

Cryoablation has been successfully used to treat various type of solid tumors, including breast carcinomas. This ablation method has the advantage of being a minimally invasive procedure useful in various clinical situations, including early breast cancer and metastatic breast cancer, when co-morbidities preclude the use of surgical treatment. However, due to the small sample size of the available studies, reliable and definitive conclusions on the usefulness of cryoablation in patients with breast cancer could not be drawn. In fact, many aspects necessitate to be elucidated, regarding technical issues, indications, efficacy, imaging follow-up, and possible advantages over other percutaneous ablative methods. This review article has the aim to clarify the current evidence supporting cryoablation of breast cancer, and discuss the future perspectives, including those arising from the new studies on immunological effects related to cryoablation.

Cryosurgery for primary breast cancers, its biological impact, and clinical outcomes

Recently, a number of new minimally invasive image-guided percutaneous ablation treatments, including cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused ultrasound, laser ablation, and irreversible electroporation have been developed. Several studies have shown the feasibility and safety of these cryoablation therapies for the treatment of benign breast tumors and small invasive breast cancer. Although the complete response rate of cryoablation for breast cancer is reported to be relatively good, most studies enrolled a small number of patients, and so reliable conclusions could not be drawn. In this review, we introduce the mechanisms of action of cryoablation, and summarize the current literature on the efficacy and safety of cryoablation for breast cancer. Cryoablation also induces an immunomodulatory effect, which is an interesting topic of research in the era of immune checkpoint inhibitors. Cryoablation for primary tumor may enhance the treatment effect of immune checkpoint inhibitors in patients with breast cancer. Further investigations of this new therapeutic strategy are needed.

Enhancing the Value Chain to Increase Customer Satisfaction and Build Successful Breast Imaging Practices

The US health care industry is increasingly shifting to a value seeking mindset. The breast imaging value chain elucidates how breast imaging radiologists generate and deliver value to their customers, who include both patients and referring health care providers. The breast imaging value chain can be used by radiologists to improve operational effectiveness and to plan new value creation strategically. The overarching goals are increased customer satisfaction and successful practices.

Microwave ablation of benign breast tumors: a prospective study with minimum 12 months follow-up

PURPOSE

This prospective study was to evaluate clinical outcomes of microwave ablation (MWA) of benign breast tumors with minimum 12 months follow up.

METHODS

With approval of the institutional ethics committee and written informed consent, 56 patients with 107 biopsy-proved breast benign tumors were recruited from November, 2013 to April, 2017. MWA with ultrasound (US) guidance was performed under local anesthesia. During the procedure, pull-back technique was used for tumors larger than 1.0 cm in diameter and hydro-dissection technique was used for tumors adjacent to skin, pectoralis and areola. Clinical outcomes were followed up by physical examination and medical images including US, contrast enhanced US and MR.

RESULTS

The maximum diameter of these tumors was 1.6 ± 0.8 cm. MWA was successfully performed with the median 120 s of duration (ranging 20-1100 s). Technical success was achieved in all patients. At the median follow-up of 20.5 months (ranging 12-53 months), the mean volume reduction ratios (mVRRs) of tumors were 77.1 ± 8.2%, 84.3 ± 10.6%, 93.3 ± 8.2% at follow-up of 12, 18, 24 months (p < .0001), respectively. Compared with 92% of masses were palpable before ablation, mass palpabilities were 40%, 11%, 5% at follow-up of 12, 18, 24 months (p < .001), respectively. Cosmetic satisfaction was reported excellent or good in 100% of patients.

CONCLUSIONS

As a safe and effective minimally invasive modality for inactivating benign breast tumors in situ, MWA achieved optimistic clinical outcomes on volume reduction and cosmetic satisfaction after minimum 12 months follow-up.

Treatment Minimization in Older Patients With Early-Stage Breast Cancer

The management of early-stage breast cancer in older patients is complex and requires a careful balance of the risk of cancer death with the competing risks of comorbidities and treatment-related toxicity in women with largely favorable disease. As the US population continues to age, oncologists will increasingly encounter this clinical challenge. Several strategies involving each core component of breast cancer therapy have been investigated to minimize treatment in these patients while still maintaining acceptable outcomes. These include omission of primary tumor resection, surgical axillary evaluation, systemic chemotherapy, and/or radiotherapy, as well as reduction in radiotherapy treatment volume (partial breast irradiation) or total treatment time (hypofractionation). We review these strategies and the literature supporting their use, as well as future directions for treatment minimization.

Successful cryoablation of breast cancer

The current standard of care for screen-detected breast cancers is surgical excision. Cryotherapy is a promising non- surgical alternative treatment for these cancers and is performed under local anesthesia as an outpatient, circumventing the risks that come with an operation. New research also shows promising results for the treatment of breast cancer when cryotherapy is combined with immune modulation as it may help prevent tumor recurrence. We herein report a case of breast cancer treated successfully with cryoablation. A brief literature review of cryoablation as a treatment for breast cancer is added.

Magnetic Resonance Mediated Radiofrequency Ablation

To introduce magnetic resonance mediated radiofrequency ablation (MR-RFA), in which the MRI scanner uniquely serves both diagnostic and therapeutic roles. In MR-RFA scanner-induced RF heating is channeled to the ablation site via a Larmor frequency RF pickup device and needle system, and controlled via the pulse sequence. MR-RFA was evaluated with simulation of electric and magnetic fields to predict the increase in local specific-absorption-rate (SAR). Temperature-time profiles were measured for different configurations of the device in agar phantoms and ex vivo bovine liver in a 1.5 T scanner. Temperature rise in MR-RFA was imaged using the proton resonance frequency method validated with fiber-optic thermometry. MR-RFA was performed on the livers of two healthy live pigs. Simulations indicated a near tenfold increase in SAR at the RFA needle tip. Temperature-time profiles depended significantly on the physical parameters of the device although both configurations tested yielded temperature increases sufficient for ablation. Resected livers from live ablations exhibited clear thermal lesions. MR-RFA holds potential for integrating RF ablation tumor therapy with MRI scanning. MR-RFA may add value to MRI with the addition of a potentially disposable ablation device, while retaining MRI's ability to provide real time procedure guidance and measurement of tissue temperature, perfusion, and coagulation.

Advances in breast intervention: where are we now and where should we be?

In the past four decades, a variety of methods for minimal or non-invasive diagnosis and treatment of breast cancer have been introduced. Although breast imaging has become more and more specific for diagnosis, specimen biopsy with histopathological confirmation is still necessary. Core-needle biopsy under ultrasound guidance is the appropriate first choice for the diagnosis of most lesions. Fine-needle aspiration is of interest for identification of the presence of metastatic disease in abnormal lymph nodes. For microcalcifications, vacuum-assisted biopsy is recommended, especially with stereotactic guidance. In recent years different therapeutic techniques have been developed for the treatment of solid lesions, including breast cancer. Certainly, with the improvement of technology and medical scientific progress, it is becoming more common to use minimal- or non-invasive therapies. The proposed minimally invasive techniques may offer complete treatment of breast cancer, with better cosmetic results, less psychological stress, and shorter hospital stays. In this article, the strengths and weaknesses of the different diagnostic and therapeutic techniques are presented, and promising techniques for the future are discussed.

Cryoablation of Primary Breast Cancer in Patients with Metastatic Disease: Considerations Arising from a Single-Centre Data Analysis

Background

Patients presenting with stage IV breast cancer might benefit by removal of the primary tumor. We report our experience with CT-guided cryoablation of the primary tumor, with the aim of evaluating its role in this subgroup of patients.

Patients and Methods

Data of 35 patients with mean age of 58 years with breast cancer at stage IV submitted to CT-guided cryoablation of the primary tumor between 2010 and 2016 were prospectively evaluated. All patients, except three, were preoperatively and postoperatively evaluated with breast MRI to assess the extent of tumor necrosis. Retreatment was performed in case of incomplete ablation.

Results

Mean tumor size was 3.02 ± 1.4 cm. Six patients had multicentric disease. Complete tumor necrosis was 85.7% and 100% at 2-month and 6-month follow-up, respectively, as 5 patients with tumors > 3 cm required a redo cryoablation. No patient developed major complications. Minor side effects occurred in 30 patients (82%). All patients were discharged the same day of the procedure. During a mean follow-up of 46 months (range 3–84), 7 patients (20%) experienced local recurrences that were treated with redo cryoablation, and 7 (20%) died for disease progression.

Conclusions

Our results suggest that cryoablation of the primary tumor is safe and effective in the treatment of patients presenting with stage IV breast cancer.

Ablative techniques for the treatment of benign and malignant breast tumours

Minimally invasive techniques like high intensity focused ultrasound, radiofrequency ablation, cryo-ablation, laser ablation and microwave ablation have been used to treat both breast fibroadenomata and breast cancer as an alternative to surgical excision, potentially reducing the complications, improving cosmesis and reducing hospital stay. This review describes the most common minimally invasive techniques available, their history and some of the studies performed with these techniques in both benign and malignant lesions. In addition we described some of the difficulties of using these minimally invasive techniques such as optimization of anaesthesia, imaging and immobilisation in order to increase the complete histopathological ablation rates.