Focused ultrasound ablation of a large canine oral tumor achieves efficient tumor remission: a case report

Ultrasound Combination to Improve the Efficacy of Current Boron Neutron Capture Therapy for Head and Neck Cancer

Boron neutron capture therapy (BNCT) is radiotherapy in which a nuclear reaction between boron-10 (10B) in tumor cells and neutrons produces alpha particles and recoiling 7Li nuclei with an extremely short range, leading to the destruction of the tumor cells. Although the neutron source has traditionally been a nuclear reactor, accelerators to generate neutron beams have been developed and commercialized. Therefore, this treatment will become more widespread. Recurrent head and neck cancer (HNC) close to the body surface is considered a candidate for BNCT using the boron compound boronophenylalanine (BPA) and has been found to be highly responsive to this treatment. However, some cases recur early after the completion of the treatment, which needs to be addressed. Ultrasound is a highly safe diagnostic method. Ultrasound with microbubbles is expected to promote the uptake of BPA into tumor cells. Ultrasound also has the ability to improve the sensitivity of tumor cells to radiotherapy. In addition, high-intensity focused ultrasound may improve the efficacy of BNCT via its thermal and mechanical effects. This review is not systematic but outlines the current status of BPA-based BNCT and proposes plans to reduce the recurrence rate of HNC after BNCT in combination with ultrasound.

Enabling Chemo-Immunotherapy with HIFU in Canine Cancer Patients

High intensity focused ultrasound (HIFU) is a promising non-invasive technique for treating solid tumors using thermal and histotripsy-based mechanical ablation. However, its clinical significance in different tumor types is not fully understood. To assess its therapeutic efficacy and immunomodulatory properties, we compared HIFU thermal ablation and histotripsy ablation in dogs with spontaneous tumors. We also evaluated the ability of non-ablative HIFU-based mild hyperthermia (40-45 ºC) to improve Doxorubicin delivery and immunomodulation. Our results showed that HIFU thermal ablation induced tumor remission in the majority of treated patients over 60 days, while histotripsy achieved partial response to stable disease persistence. The adverse effects of thermal ablation were minor to moderate, while histotripsy exposures were relatively well-tolerated. Furthermore, we observed a correlation between HIFU-therapeutic response and serum anti-tumor cytokine profiles and the presence of functionally active cytotoxic immune cells in patients. Similarly, Doxorubicin-treated patients showed improved drug delivery, efficacy, and anti-tumor immune responses with HIFU hyperthermia. In conclusion, our study demonstrates that depending on the tumor type and treatment parameters, HIFU treatments can enable tumor growth control, immune activation, and chemotherapy in veterinary patient. These findings have significant clinical implications and highlight the potential of HIFU as a promising cancer treatment approach.

Treatment of mammary cancer with focused ultrasound: A pilot study in canine and feline patients

In recent years, veterinary medicine has expanded its practices beyond conventional methods, gradually integrating the Focused Ultrasound (FUS) technology in the care of companion animals like dogs and cats. The current study aimed to examine the feasibility and provide insights into the application of thermal FUS in canine and feline mammary cancer therapy. FUS was delivered by a 2-MHz single-element spherically focused ultrasonic transducer as integrated with an existing robotic positioning device. The functionality of the FUS system and sonication protocol in efficiently and safely ablating live tissue was initially validated in a rabbit thigh model in a laboratory environment. Nine (9) dogs and cats with superficial mammary cancer were recruited through a dedicated campaign according to specific safety criteria. The veterinary patients underwent FUS ablation followed by immediate surgical resection of the entire malignancy. Histopathology examination demonstrated well-defined regions of coagulative necrosis in all treated tumors with no off-target damage. Further study with a larger patient population is needed to confirm the current findings and demonstrate the safety and feasibility of complete FUS ablation of deep-seated tumors.

Treatment of canine and feline sarcoma using MR-guided focused ultrasound system

PURPOSE

In recent years, veterinary medicine has enhanced its applications beyond traditional approaches, progressively incorporating the Focused Ultrasound (FUS) technology. This study investigated the ability of FUS to precisely ablate naturally occurring canine and feline soft tissue sarcomas (STS).

METHODS

Six dogs and four cats with superficial tumours were enrolled in the study. The tumours were treated with a Magnetic Resonance guided FUS (MRgFUS) robotic system featuring a single element spherically focused transducer of 2.6 MHz. The tumours were then removed by surgery and sent for hematoxylin and eosin (H&E) staining.

RESULTS

The MRgFUS system was capable of inflicting well-defined overlapping lesions in the tumours. The anatomical sites of the treated tumours were the neck, leg, face, back and belly. Coagulative necrosis was evidenced by histopathology assessment in 80% of cases.

CONCLUSION

Therefore, this technology can be a therapeutic solution for veterinary cancer and a model for advancing the knowledge on human STS.

Local tumour nanoparticle thermal therapy: A promising immunomodulatory treatment for canine cancer

Distinct thermal therapies have been used for cancer therapy. For hyperthermia (HT) treatment the tumour tissue is heated to temperatures between 39 and 45°C, while during ablation (AB) temperatures above 50°C are achieved. HT is commonly used in combination with different treatment modalities, such as radiotherapy and chemotherapy, for better clinical outcomes. In contrast, AB is usually used as a single modality for direct tumour cell killing. Both thermal therapies have been shown to result in cytotoxicity as well as immune response stimulation. Immunogenic responses encompass the innate and adaptive immune systems and involve the activation of macrophages, dendritic cells, natural killer cells and T cells. Several heat technologies are used, but great interest arises from nanotechnology-based thermal therapies. Spontaneous tumours in dogs can be a model for cancer immunotherapies with several advantages. In addition, veterinary oncology represents a growing market with an important demand for new therapies. In this review, we will focus on nanoparticle-mediated thermal-induced immunogenic effects, the beneficial potential of integrating thermal nanomedicine with immunotherapies and the results of published works with thermotherapies for cancer using dogs with spontaneous tumours, highlighting the works that evaluated the effect on the immune system in order to show dogs with spontaneous cancer as a good model for evaluated the immunomodulatory effect of nanoparticle-mediated thermal therapies.

High intensity focused ultrasound for the treatment of solid tumors: a pilot study in canine cancer patients

PURPOSE

To investigate the safety, feasibility, and outcomes of High-Intensity Focused Ultrasound (HIFU) for the treatment of solid tumors in a spontaneous canine cancer model.

METHODS

Dogs diagnosed with subcutaneous solid tumors were recruited, staged and pretreatment biopsies were obtained. A single HIFU treatment was delivered to result in partial tumor ablation using a commercially available HIFU unit. Tumors were resected 3-6 days post HIFU and samples obtained for histopathology and immunohistochemistry. Total RNA was isolated from paired pre and post treated FFPE tumor samples, and quantitative gene expression analysis was performed using the nCounter Canine IO Panel.

RESULTS

A total of 20 dogs diagnosed with solid tumors were recruited and treated in the study. Tumors treated included Soft Tissue Sarcoma (n = 15), Mast Cell Tumor (n = 3), Osteosarcoma (n = 1), and Thyroid Carcinoma (n = 1). HIFU was well tolerated with only 1 dog experiencing a clinically significant adverse event. Pathology confirmed the presence of complete tissue ablation at the HIFU targeted site and immunohistochemistry indicated immune cell infiltration at the treated/untreated tumor border. Quantitative gene expression analysis indicated that 28 genes associated with T-cell activation were differentially expressed post-HIFU.

CONCLUSIONS

HIFU appears to be safe and feasible for the treatment of subcutaneous canine solid tumors, resulting in ablation of the targeted tissue. HIFU induced immunostimulatory changes, highlighting the canine cancer patient as an attractive model for studying the effects of focal ablation therapies on the tumor microenvironment.