A Pilot Study in High Intensity Focused Ultrasound Ablation of Soft Tissue Sarcoma and Small Symptomatic Intra-abdominal Desmoid Tumours
Around 3,300 people are diagnosed with soft tissue sarcoma (STS) each year in the UK, and a significant proportion of STS diagnoses are in people aged under 30 years. STS can arise from various tissue types and is comprised of over 50 tumour types. Although STS is treated with a combination of surgery, radiotherapy and chemotherapy, the prognosis is relatively poor with a five-year survival rate of 54%. There is an unmet need for further treatment modalities in STS. High intensity focused ultrasound (HIFU) is a non-invasive way of treating cancers with minimal side effects, low complication rate and quick recovery. Ultrasound waves are used to destroy tumour cells and improvements in technology and experience are enabling complete destruction of tumour. HIFU also releases tumour antigens, increasing the immune response against cancer. HIFU has received FDA approvals for several indications, including bone metastases and we are using a CE-approved HIFU device in Oxford (UKCA-approvals anticipated for 2023). There have been some publications from China showing promise in STS, however this technology needs further evaluation within the UK's healthcare setting. This study will recruit patients with both resectable and unresectable STS, in addition to unresectable small symptomatic desmoid tumours. 12-16 patients, and a minimum of 10 patients with malignant STS, will be treated over a maximum recruitment period of three years. HIFU treatment will be carried out as a day case procedure, and patients will be expected to be discharged home the same day. The study is designed to generate evidence regarding safety and feasibility of HIFU for ablation of STS and intra-abdominal desmoids. In addition, the study is anticipated to provide information about the efficacy of HIFU against these tumour types which can help in the design of later phase studies. Short-term outcomes include feasibility, safety and the completeness of destruction of the tumour. Long-term outcomes include one-year survival, local recurrence and quality of life metrics (including pain scores). The study will also look at immunological response following ablation of STS using both blood and tumour samples pre- and post-HIFU ablation.
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⁃ The participant is eligible for the study if they are:
⁃ Willing and able to give informed consent for participation in the study.
⁃ Aged 18 years or above.
⁃ Diagnosed with histologically-confirmed and HIFU-targetable soft tissue sarcoma of several subtypes, including but not necessarily limited to:
• Malignant fibrous histiocytoma
• Undifferentiated (pleomorphic) sarcoma
• Fibrosarcoma and fibromyxoid sarcoma (fibroblastic sarcomas)
• Leiomyosarcoma
• Liposarcoma
• Malignant peripheral nerve sheath tumour
• Retroperitoneal sarcoma
• Rhabdomyosarcoma
• Synovial sarcoma
• Sacral chordoma (following amendment)
• Desmoid tumours (intra-abdominal, including extra-peritoneal tumours which involve the abdominal wall)
⁃ Have at least one of the following:
• Untreated or recurrent primary resectable STS tumour 1-5cm diameter, targetable by HIFU
• Infield recurrent primary resectable STS tumour of \>1cm diameter, targetable by HIFU
• Primary or metastatic STS unsuitable for resection or further chemo- or radiotherapy, targetable by HIFU
• Small (1-8cm) symptomatic intra-abdominal desmoid tumour, targetable by HIFU, which is unsuitable for surgery (or patient has previously refused surgery)
⁃ Have life expectancy of over 12 months and a World Health Organisation (WHO) performance status of less than or equal to 1.
⁃ Be able to attend Churchill Hospital and Nuffield Orthopaedic Center, Oxford, potentially for multiple visits, and thus be based in the UK.
⁃ Willing to allow his or her GP and Consultant to be notified of participation in the study.
⁃ Able and willing to give written informed consent, indicating that they are aware of the investigational nature of this study and potential risks, and able to comply with the protocol for the duration of the study, including scheduled follow-up visits and examinations.