Clinical Research Directory

Histotripsy for Peritoneal Tumour and Lymph Node: a Pilot Study

Peritoneal cancer is tricky to be managed. It is not easy to be detected or diagnosed at early stage without symptom, or with common symptoms of many diseases or discomfort and often leads to advance stage at time of diagnosis with few treatment options and limited life span. It is also challenging to handle peritoneal tumour as it usually involves large area in peritoneum, or spread widely throughout the surface of peritoneum if metastatic from other origins. Systemic therapy is the common way to treat peritoneal cacner if the disease is inoperable. However, the unsatisfied penetration rate significantly limits the anti-tumour effect of intraperitoneal chemotherapy even after various attempts and most approaches demonstrated limited efficiency. Effective treatment for peritoneal cancer is still scarce and necessary. While the tumour nature of peritoneal tumour consists of solid tumour and soft tissue tumour, depends on primary or secondary disease, Histotripsy, which can be used on most kinds of solid tumour as well as soft tissue tumour, may yield a new direction and insight on peritoneal cancer management. Histotripsy is currently indicated for liver tumours, approved by FDA and has been investigated for many disease types in preclinical researches and carried out several clinical trials for liver tumour, benign prostatic hyperplasia, liver tumour combined with systemic therapy, renal tumour, pancreatic tumour, soft tissue tumours, abdominal tumour, calcific aortic valves, and pain in plantar fasciitis, with encouraging results in some clinical trials. As most clinical trials above are for solid tumour and soft tissue tumour that suit the tumour nature of peritoneal tumour, we believe that Histotripsy is also safe and feasible on human with peritoneal tumour. Considering nodal involvement also frequently comes with peritoneal cancer, we would like to conduct an investigation for Histotripsy in peritoneal tumour and lymph node. Although the result of clinical trial in peritoneal tumour and lymph node are not available yet, HIFU (High Intensity Focused Ultrasound) as another non-invasive ablation also delivered by ultrasound wave which has been in clinical use for many years worldwide can be referenced for Histotripsy. The core difference of HIFU and Histotripsy is, HIFU employs thermal energy to induce coagulative necrosis, while Histotripsy utilises mechanical cavitation to disrupt tumour tissues and preserves adjacent critical structure without the issue of heat, which makes it safer than HIFU. According to some reviews of HIFU, it is obvious that HIFU is feasible and safe without significant adverse event for abdominal tumours including peritoneal tumour and lymph node. Consequently, Histotripsy as a non-thermal ablation and is considered to be safer than HIFU, should also be feasible and safe for peritoneal tumour and lymph node. Hence, it is time for Hong Kong to launch the investigation on the feasibility, safety, and efficacy of Histotripsy in peritoneal tumour and lymph node.

Baseline Evaluation of Lymph Nodes in the Lower Quadrant Young People Using Point of Care Ultrasound (BELLY-POCUS)

Abdominal pain is one of the commonest presentations to the paediatric emergency department. Many children are brought to the PED due to concerns about surgical intra-abdominal pathology such as appendicitis. Mesenteric adenitis is commonly attributed as a cause of the patient's pain but is done so without confirmatory imaging findings and as a diagnosis of exclusion. There is a paucity of evidence pertaining to the sonographic findings of mesenteric adenitis. The investigators aim to categorise the normal appearances using POCUS in patients presenting to the paediatric emergency department without any abdominal or infectious complaint, in order to describe the range of normal lymph node numbers and size present on scan. By defining what's normal, the ultimate aim will be to use POCUS to actively identify abnormalities that diagnose mesenteric adenitis.

Randomized Study Comparing Two Dosing Schedules for Hypofractionated Image-Guided Radiation Therapy

The purpose of this study is to find out which way of giving high-dose radiation works best for treatment of cancer that has spread to bone, the spine, soft tissue, or lymph nodes. This study will look at the effects, good and/or bad, of giving 27 Gy in three fractions (3 days) or 24 Gy in one fraction (1 day) using image-guided intensity-modulated radiotherapy (IG-IMRT). IG-IMRT is radiation that is given directly to the cancer site and reduces the exposure to normal tissue. Currently there are no studies that compare the effects of giving radiation in either hypofractionated doses (higher total doses of radiation spread out over several treatment days) or a single-fraction dose (entire radiation dose given in one treatment session). The patient may be asked to participate in an additional part of this study where we will get a a (DW/DCE) MRI before treatment start and within one hour after radiation treatment. If the patient is asked to take part in this portion of the study, all they will need to do is get up to 3 MRIs with standard contrast injection. The purpose of this is to see if as a result of the treatment there are changes in the blood flow going to the cancer which could suggest that the treatment may be successful. In addition some patients can present new lesions and may be asked if they would like to have these new lesions treated on the protocol. If they are given this option, this will not extend their follow up period. The follow up of the new lesions will match with the prior follow up dates.

The eValuation of Sources of vIBRAtioN for Vibrational Shear Wave elasTography

Patients suffering with Head and Neck Cancer often must wait 3 months or more to know if their treatment has been effective, which can be very stressful. The investigators are developing an imaging tool that may be useful to help clinicians understand if patients need secondary treatment, surgery to remove lymph nodes in the neck, sooner. Evidence suggests that lymph nodes containing cancer are stiffer than normal lymph nodes. The investigator's tool, vibrational shear wave elastography, measures the stiffness of tissue using shear waves. Gentle vibrations, like those of a mobile phone, applied to the skin surface can create shear waves in the body. The investigators use ultrasound imaging and an algorithm the investigators have developed to measure shear wave speed which is related to tissue stiffness. The algorithm is applied to ultrasound images using software we have written. To help develop the software the investigators wish to explore different ways of creating shear waves in the neck and see how well the investigators can detect shear waves as they pass through tissues such as muscle, the thyroid and other glands in the neck. The investigators will recruit healthy volunteers to participate in this study. The investigators will use external vibrational sources gently placed against the neck in different positions to understand what the best approach to achieve the best measurement of tissue stiffness is. The investigators will also ask healthy volunteers to generate vibrations themselves using their vocal cords, a process called vocal fremitus. Participants will be asked utter 'aaa' sounds at different pitches, and the investigators will image the shear wave generated by the vibrating vocal cords. The investigators will also ask volunteers how comfortable they found the external vibrations and how easy or difficult they found it to utter and hold the sounds. This study is an exploratory benchmarking study of the software that will help the investigators develop our technique further, and design and build optimal equipment before testing it in patients.