Efficacy and Safety of Radiofrequency Ablation for Breast Cancer Smaller Than 2 cm: A Systematic Review and Meta-Analysis

Effects of low-frequency ultrasound combined with microbubbles on breast cancer xenografts in nude mice

The aim of this study was to explore the effects of low-frequency ultrasound (US) combined with microbubbles (MBs) on breast cancer xenografts and explain its underlying mechanisms. A total of 20 xenografted nude mice were randomly divided into four groups: a group treated with US plus MBs (the US + MBs group), a group treated with US alone (the US group), a group treated with MBs alone (the MBs group), and a control group. In different groups, mice were treated with different US and injection regimens on an alternate day, three times in total. Histological changes, apoptosis of cells, microvascular changes, and the apoptosis index (AI) and microvascular density (MVD) of the breast cancer xenograft were analyzed after the mice were sacrificed. Results indicated that the tumor volume in the US + MBs group was smaller than that in the other three groups (p < 0.001 for all). The rate of tumor growth inhibition in the US + MBs group was significantly higher than that in the US and MBs groups (p < 0.001 for both). There were no significant differences in histological changes among the four groups. However, the AI was higher in the US + MBs group than that in the other three groups while the MVD was lower (p < 0.001 for all). All in all, low-frequency US combined with MBs can effectively slow down the growth of breast cancer in nude mice. In summary, low-frequency US combined with MBs has a significant effect on breast cancer treatment. Cavitation, thermal effects, and mechanical effects all play a vital role in the inhibition of tumor growth.

Shear-Wave Elastography Gradient Analysis of Newly Diagnosed Breast Tumours: A Critical Analysis

BACKGROUND

A better understanding of the peritumoral stroma changes due to tumour invasion using non-invasive diagnostic methods may improve the differentiation between benign and malignant breast lesions. This study aimed to assess the correlation between breast lesion differentiation and intra- and peritumoral shear-wave elastography (SWE) gradients.

METHODS

A total of 135 patients with newly diagnosed breast lesions were included. Intratumoral, subsurface, and three consecutive peritumoral SWE value measurements (with three repetitions) were performed. Intratumoral, interface, and peritumoral gradients (Gradient 1 and Gradient 2) were calculated using averaged SWE values. Statistical analysis included descriptive statistics and an ordinary one-way ANOVA to compare overall and individual gradients among Breast Imaging-Reporting and Data System (BI-RADS) 2, 3, and 5 groups.

RESULTS

Malignant tumours showed higher average SWE velocity values at the tumour centre (BI-RADS 2/3: 4.1 ± 1.8 m/s vs. BI-RADS 5: 4.9 ± 2.0 m/s, p = 0.04) and the first peritumoral area (BI-RADS 2/3: 3.4 ± 1.8 m/s vs. BI-RADS 5: 4.3 ± 1.8 m/s, p = 0.003). No significant difference was found between intratumoral gradients (0.03 ± 0.32 m/s vs. 0.0 ± 0.28 m/s; p > 0.999) or gradients across the tumour-tissue interface (-0.17 ± 0.18 m/s vs. -0.13 ± 0.35 m/s; p = 0.202). However, the first peritumoral gradient (-0.16 ± 0.24 m/s vs. -0.35 ± 0.31 m/s; p < 0.0001) and the second peritumoral gradient (-0.11 ± 0.18 m/s vs. -0.22 ± 0.28 m/s; p = 0.037) were significantly steeper in malignant tumours. The AUC was best for PTG1 (0.7358) and PTG2 (0.7039). A threshold value for peritumoral SWI PT1 above 3.76 m/s and for PTG1 below -0.238 m/s·mm-1 indicated malignancy in 90.6% of cases.

CONCLUSIONS

Evaluating the peritumoral SWE gradient may improve the diagnostic pre-test probability, as malignant tumours showed a significantly steeper curve of the elasticity values in the peritumoral stroma compared to the linear regression with a relatively flat curve of benign lesions.

Efficacy of Radiofrequency Ablation in Autonomous Functioning Thyroid Nodules: A Comprehensive Systematic Review and Meta-analysis

BACKGROUND

Radiofrequency ablation (RFA) is a minimally invasive outpatient procedure that has recently emerged as a treatment option for autonomous functioning thyroid nodules (AFTNs), offering a less invasive alternative to surgery. The objective of this systematic review and meta-analysis is to evaluate the efficacy of RFA for AFTNs.

METHOD

Global databases of PubMed, Scopus, Embase, Web of Science, and Cochrane Library were systematically searched from 1990 until January 5, 2024, for studies on AFTNs undergoing RFA that presented volume reduction ratio (VRR) for at least one of 1, 3, 6 or 12 months post-operative follow-up with the results presented as means. The primary outcomes were VRR and TSH normalization rate, and the secondary outcomes were the cosmetic score, symptom score, and post-procedure complications. Heterogeneity was assessed by Cochrane and I2 statistics, and a random-effects model was used for meta-analysis. The study protocol was registered on PROSPERO (CRD42024499932).

RESULTS

A total of 10 eligible studies with a total sample size of 254 were included. The pooled VRR after 1, 3, 6, and 12 months of follow-up post-treatment with RFA was 46.6% (95% CI: 40.3-52.9%), 62% (95% CI: 57.6-66.4%), 67.4% (95% CI:62.3-72.6%), and 77.2% (95% CI: 79.2-81.5%), respectively. The overall rate of TSH normalization was 76.4% (95% CI: 58.1-88.4%). Based on included studies the overall rate of subclinical hypothyroidism as one of the most important side effects of this method was 4% (95% CI: 1.9%-8.1%).

CONCLUSION

RFA emerges as a promising non-surgical treatment for AFTNs, showing high rates of TSH normalization, tumor size reduction, and improved cosmetic and symptom scores. However, further research is needed to compare RFA with surgical methods and assess long-term outcomes.

Intraductal photothermal ablation: a noninvasive approach for early breast cancer treatment and prevention

Background: Innovative treatment strategies for early-stage breast cancer (BC) are urgently needed. Tumors originating from mammary ductal cells present an opportunity for targeted intervention. Methods: We explored intraductal therapy via natural nipple openings as a promising non-invasive approach for early BC. Using functional Near-infrared II (NIR-II) nanomaterials, specifically NIR-IIb quantum dots conjugated with Epep polypeptide for ductal cell targeting, we conducted in situ imaging and photothermal ablation of mammary ducts. Intraductal administration was followed by stimulation with an 808 nm laser. Results: This method achieved precise ductal destruction and heightened immunological responses in the microenvironment. The technique was validated in mouse models of triple-negative BC and a rat model of ductal carcinoma in situ, demonstrating promising therapeutic potential for localized BC treatment and prevention. Conclusion: Our study demonstrated the effectiveness of NIR-II nanoprobes in guiding non-invasive photothermal ablation of mammary ducts, offering a compelling avenue for early-stage BC therapy.

Minimally invasive treatment of early, good prognosis breast cancer-is this feasible?

Breast cancer screening programmes frequently detect early, good prognosis breast cancers with significant treatment burden for patients, and associated health-cost implications. Emerging evidence suggests a role for minimally invasive techniques in the management of these patients enabling many women to avoid surgical intervention. Minimally invasive techniques include vacuum-assisted excision, cryoablation, and radiofrequency ablation. We review published evidence in relation to the risks and benefits of each technique and discuss ongoing trials. Data to date are promising, and we predict a trend towards minimally invasive treatment for early, good-prognosis breast cancer as technical skills, suitability criteria, and follow-up protocols are established.

Non-surgical ablation for breast cancer: an emerging therapeutic option

Non-surgical ablation is emerging as an alternative local therapy option for patients with early-stage breast cancer and encompasses two main types of percutaneous therapeutic procedures: radiofrequency ablation and cryoablation. Both techniques involve obliteration of a spherical lesion and feasibility studies have shown that complete tumour ablation is achievable with good or excellent cosmetic results. Although few clinical studies have directly compared non-surgical ablation with conventional surgical resection, observational studies indicate that clinical outcomes are favourable with acceptable rates of local control and no detriment to long-term survival. There remain outstanding issues with these percutaneous ablative techniques that require resolution before they could be incorporated into routine clinical practice. Hence, a consensus meeting was convened to discuss the challenges of non-surgical ablation and clarify indications for its use alongside clinical management pathways. In this Policy Review we will address some of the broader biological aspects of non-surgical ablation, including immune-modulatory effects and potential novel applications for the future.

Peripheral T-cell subsets in radiofrequency ablation for tumors from different origins

BACKGROUNDS

Radiofrequency ablation (RFA) is known to destroy tumoral tissue and activate immune cells. This study aimed to investigate the impact of RFA on peripheral T-cell responses and its relationship with tumor origin and hepatitis status.

METHODS

A retrospective analysis was conducted on 62 patients with various types of tumors, including hepatocellular carcinoma, colorectal cancer, lung cancer, breast cancer, and others, who underwent RFA treatment between June 2017 and December 2018. Blood samples were collected before and one day after RFA treatment. The peripheral T-cell subsets were measured by flow cytometry, and their changes were analyzed.

RESULTS

The study found a decrease in the CD4+CD8-and CD4-CD8+ T-cell subsets after RFA, but no significant changes were observed in the populations of CD4+CD8+ and the CD4+CD8-/CD4-CD8+ ratio. Furthermore, no significant differences were observed in peripheral T-cell subsets concerning tumor type or hepatitis status.

CONCLUSIONS

The study suggests that RFA treatment may have a short-term impact on peripheral T-cell responses, characterized by a decrease in certain T-cell subsets. However, these changes do not seem to be related to the tumor type or hepatitis status of the patients.

Magnetic resonance imaging-guided radiofrequency ablation of breast cancer: a current state of the art review

With a gradual increase in breast cancer incidence and mortality rates and an urgent need to improve patient prognosis and cosmetology, magnetic resonance imaging (MRI)-guided radiofrequency ablation (RFA) therapy has attracted wide attention as a new treatment method for breast cancer. MRI-RFA results in a higher complete ablation rate and extremely low recurrence and complication rates. Thus, it may be used as an independent treatment for breast cancer or adjuvant to breast-conserving surgery to reduce the extent of breast resection. Furthermore, with MRI guidance, accurate control of RFA can be achieved, and breast cancer treatment can enter a new stage of minimally invasive, safe, and comprehensive therapy. With progress in MR thermometry technology, the applications of MRI are expected to broaden.

Metastasis-directed therapy for oligometastases in breast cancer

The concept of oligometastases was first proposed to describe a disease state between localized cancer and extensive metastasis. After the emergence of variations in the definition of oligometastasis, in April 2020 the European Society for Radiotherapy and Oncology and the European Organization for Research and Treatment of Cancer defined oligometastases as the presence of one to five metastatic lesions that can be safely treated. However, the pathogenesis of oligometastases remains unknown, and it is uncertain which patients will benefit from metastasis-directed therapy. Breast cancer with oligometastases is generally managed with systemic therapy. Retrospective studies have suggested that the addition of metastasis-directed therapy, such as surgery, radiofrequency ablation and stereotactic body radiation therapy, may increase overall survival in breast cancer patients with oligometastases, but as yet there have been no prospective studies. Phase II trials of stereotactic body radiation therapy or fractionated irradiation for oligometastases of breast cancer have demonstrated impressive rates of local control and overall survival. Although the efficacy of stereotactic body radiation therapy in the SABR-COMET was largely anticipated, it is noteworthy that only 18% of the patient population had breast cancer. For this reason, various trials were planned or are being conducted globally to investigate the efficacy of metastasis-directed therapy for oligometastases of breast cancer. Metastasis-directed therapy for oligometastases has been shown to be effective, and stereotactic body radiation therapy and other therapies are commonly used internationally and are considered to be safe. However, the efficacy of metastasis-directed therapy for oligometastases has not yet been proven. The results of future clinical trials are thus eagerly awaited.

Non-Surgical Definitive Treatment for Operable Breast Cancer: Current Status and Future Prospects

This article reviews the results of various non-surgical curative treatments for operable breast cancer. Radiotherapy is considered the most important among such treatments, but conventional radiotherapy alone and concurrent chemoradiotherapy do not achieve high cure rates. As a radiosensitization strategy, intratumoral injection of hydrogen peroxide before radiation has been investigated, and high local control rates (75-97%) were reported. The authors treated 45 patients with whole-breast radiotherapy, followed by stereotactic or intensity-modulated radiotherapy boost, with or without a radiosensitization strategy employing either hydrogen peroxide injection or hyperthermia plus oral tegafur-gimeracil-oteracil potassium. Stages were 0-I in 23 patients, II in 19, and III in 3. Clinical and cosmetic outcomes were good, with 5-year overall, progression-free, and local recurrence-free survival rates of 97, 86, and 88%, respectively. Trials of carbon ion radiotherapy are ongoing, with promising interim results. Radiofrequency ablation, focused ultrasound, and other image-guided ablation treatments yielded complete ablation rates of 20-100% (mostly ≥70%), but long-term cure rates remain unclear. In these treatments, combination with radiotherapy seems necessary to treat the extensive intraductal components. Non-surgical treatment of breast cancer is evolving steadily, with radiotherapy playing a major role. In the future, proton therapy with the ultra-high-dose-rate FLASH mode is expected to further improve outcomes.

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.

Thermochromic Tissue-Mimicking Phantoms for Thermal Ablation Based on Polyacrylamide Gel

In recent years, thermal ablation has played an increasingly important role in treating various tumors in the clinic. A practical thermochromic phantom model can provide a favorable platform for clinical thermotherapy training of young physicians or calibration and optimization of thermal devices without risk to animals or human participants. To date, many tissue-mimicking thermal phantoms have been developed and are well liked, especially the polyacrylamide gel (PAG)-based phantoms. This review summarizes the PAG-based phantoms in the field of thermotherapy, details their advantages and disadvantages and provides a direction for further optimization. The relevant physical parameters (such as electrical, acoustic, and thermal properties) of these phantoms are also presented in this review, which can assist operators in a deeper understanding of these phantoms and selection of the proper recipes for phantom fabrication.

Interventional oncology update

Interventional Oncology (IO) is a subspecialty field of Interventional Radiology bridging between diagnostic radiology and the clinical oncology team, addressing the diagnosis and treatment of cancer. There have been many exciting advancements in the field of IO in recent years; far too many to cover in a single paper. To give each topic sufficient attention, we have limited the scope of this review article to four topics which we feel have the potential to drastically change how cancer is treated managed in the immediate future.