Histopathology of breast cancer after magnetic resonance-guided high-intensity focused ultrasound and radiofrequency ablation

High-Intensity Focused Ultrasound: A Review of Mechanisms and Clinical Applications

High Intensity Focused Ultrasound (HIFU) is an emerging and increasingly useful modality in the treatment of cancer and other diseases. Although traditional use of ultrasound at lower frequencies has primarily been for diagnostic imaging purposes, the development of HIFU has allowed this particular modality to expand into therapeutic use. This non-invasive and acoustic method involves the use of a piezoelectric transducer to deliver high-energy pulses in a spatially coordinated manner, while minimizing damage to tissue outside the target area. This review describes the history of the development of diagnostic and therapeutic ultrasound and explores the biomedical applications utilizing HIFU technology including thermally ablative treatment, therapeutic delivery mechanisms, and neuromodulatory phenomena. The application of HIFU across various tumor types in multiple organ systems is explored in depth, with particular attention to successful models of HIFU in the treatment of various medical conditions. Basic mechanisms, preclinical models, previous clinical use, and ongoing clinical trials are comparatively discussed. Recent advances in HIFU across multiple medical fields reveal the growing importance of this biomedical technology for the care of patients and for the development of possible pathways for the future use of HIFU as a commonplace treatment modality.

Assessment of Enhanced Thermal Effect Due to Gold Nanoparticles during MR-Guided High-Intensity Focused Ultrasound (HIFU) Procedures Using a Mouse-Tumor Model

An in vivo study was conducted using a mouse tumor model, to assess the utility of using gold nanoparticles (gNPs) during HIFU procedures to locally enhance heating at low powers. Tumors were grown using melanoma tumor cells (B16/F10) subcutaneously on the right flanks of mice (C57Bl/6J). Physiologically relevant concentrations (0 and 0.125%) of gNPs were directly injected into the tumors. Sonications at acoustic powers of 10 and 30 W were performed for a duration of 16 s inside a magnetic-resonance system. Temperature increases and lesion volumes were calculated and compared for procedures with and without gNPs. Histopathology study was conducted using a cleaved caspase 3 antibody and hematoxylin and eosin staining after removing the tumors from the mice. For an acoustic power of 30 W, end-of-sonication temperature increases of 25.4 ± 3.8 °C (0% gNP) and 42.2 ± 4.6 °C (0.125% gNP) were measured. Using cleaved caspase 3 antibody, it was observed that more than 1% of nuclei are affected in the case of 0.125% and 30 W but only 0.01% of nuclei are affected in the 0% case. For 30 W and a gNP concentration of 0.125%, a lesion volume of 0.33 ± 0.22 mm³ was obtained, while no lesion was observed without gNP's.

The Utrecht cohort for Multiple BREast cancer intervention studies and Long-term evaLuAtion (UMBRELLA): objectives, design, and baseline results

PURPOSE

In oncology, RCTs are often beset by slow recruitment, limited generalizability, and strong preferences for interventions by patients and physicians. The cohort multiple randomized controlled trial (cmRCT) is an innovative design with the potential to overcome those challenges. In cmRCT, a prospective cohort serves as an infrastructure for multiple RCTs. We implemented cmRCT in a clinical breast cancer setting by creating UMBRELLA-a large prospective cohort of breast cancer and DCIS patients/survivors.

METHODS

For all participants, clinical data and patient-reported outcomes (PROs, i.e., quality of life, fatigue, anxiety and depression, physical activity, work ability, and cosmetic satisfaction) are being collected at regular time-intervals for a period of 10 years. These data are being used both for observational and randomized studies. For each intervention to be tested against standard care, a subcohort of eligible patients is identified within UMBRELLA. From this subcohort, a random sample of patients is offered the intervention. Their outcomes are compared to the outcomes of patients receiving standard care.

RESULTS

So far, between October 2013 and July 2016, we have recruited 1308 participants. In this period, 1308/1486 (88%) patients who were invited for participation in UMBRELLA consented to cohort participation. Of these patients, 1138 (87%) gave broad consent for randomization to future interventions. Return rate for PROs at baseline were 80%, and varied from 67 to 74% during follow-up. Several observational studies-and the first randomized intervention study-are currently ongoing.

CONCLUSIONS

Results from UMBRELLA show that this novel study design is feasible and acceptable to patients in a clinical breast cancer setting. We invite researchers who are interested in conducting randomized or observational studies within the UMBRELLA cohort to contact the UMBRELLA scientific advisory board.