The sunlight will produce high temperature at the focal point after being focused by convex lens, which can ignite the paper or wood, can it be used to burn the tumor tissues in human body? No, because sunlight cannot penetrate human body tissues; if ultrasound is focused, it can also generate high temperature at the focal point. Focused Ultrasound Knife).
Focused ultrasound knife can focus ultrasound on the tumor in the body and kill the tumor tissue point by point and layer by layer under the surveillance of ultrasound and computer control. This non-invasive and precise and efficient feature is unique among other tumor treatment methods at present. Foreign experts have called it “the future of surgical oncology”.
Some deep tumors that are difficult for surgeons, such as pancreatic cancer, retroperitoneal tumors and some tumors that cannot be removed by surgery, such as gastric cancer, liver cancer, kidney cancer, etc., are treated with focused ultrasound knife, and the local tumor tissue undergoes coagulative necrosis or degeneration, and the tumor cells lose their original activity, which prolongs the patient’s survival and significantly improves the quality of life; for some slightly early tumor cases, focused ultrasound knife can also achieve For most patients with uterine fibroids, focused ultrasound knife can thermally coagulate the tumor outside the body, thus stopping the growth, degeneration and necrosis of the fibroids, and most of the patient’s symptoms such as bleeding and pain can be significantly improved, so the patient can avoid surgery. Focused Ultrasound Knife has been approved by the FDA, the world’s most stringent medical access system, for the treatment of fibroids. Currently, focused ultrasound knife is most commonly used for pancreatic cancer, liver cancer, uterine fibroids, retroperitoneal lymph node tumor metastasis, and ovarian cancer.
Of course, because ultrasound itself is interfered by many factors in the short propagation, head and facial tumors, chest tumors and some tumors in areas blocked by bones cannot be treated by focused ultrasound knife at present. In conclusion, focused ultrasound knife is a new treatment method for tumors with not very wide indications, but with excellent effectiveness and safety. To date, focused ultrasound knife has brought benefits to tens of thousands of patients with inoperable mid- to late-stage tumors, patients who are too old to tolerate surgery, patients with tumor recurrence and metastasis after surgery, and young patients who do not want to remove certain organs (such as uterus, limbs or breast). The focused ultrasound knife technology itself is constantly evolving, and its unique advantages have been recognized by more and more clinical experts who have taken the lead in rejecting industry bias.
I. High-intensity focused ultrasound? Principle
1.What is high-intensity focused ultrasound?
High intensity focused ultrasound (HIFU), also known as focused ultrasound knife, is called “the new technology for non-invasive treatment of tumor in the 21st century” by experts at home and abroad.
Focused ultrasound knife uses ultrasound as the energy source, utilizing its penetrating and focusability to focus the ultrasound in vitro on the lesion in vivo, and reach a high energy density at the focal point to produce an instant high temperature (70℃) to kill the tumor tissue directly. And the surrounding normal tissues are unharmed because they are not in the focus. Under the monitoring of ultrasound, focused ultrasonic knife scans along the tumor shape layer by layer, and finally causes coagulative necrosis of the whole tumor tissue.
2.The development prospect of focused ultrasound knife
Focused ultrasound knife is the hot spot in the field of tumor treatment nowadays, and a worldwide professional academic conference is held every year. Harvard University, Massachusetts Institute of Technology, Stanford University and Oxford University in the United Kingdom and other top international institutions of higher learning have all set up research institutes for this technology. For specific reasons, China is the world leader in the clinical application of focused ultrasound knife for the time being. To date, tens of thousands of tumor cases have been successfully treated in China with encouraging overall results. As an extension and expansion of the scalpel, the focused ultrasound knife has been recognized by scholars who have taken the lead in abandoning the prejudice of the industry, and tumor treatment will step into a new era of minimally invasive and high efficiency.
3.What is the lethal temperature of tumor cells?
42℃～ 43℃ 10 hours
50℃ 1-2 seconds
65℃～ 70℃ 0.25 seconds
4.Some tumor treatments, such as chemotherapy or radiotherapy, are only effective for specific tumor cells, and some other tumor cells are insensitive (ineffective) to these treatments. Are there also some tumor cells that are insensitive (ineffective) to high temperature (70℃)?
Any tumor cell dies instantly at 70°C, and the pathological change in the tumor tissue is “coagulative necrosis”. No tumor cells can tolerate the high temperature of 70℃.
5.Will Focused Ultrasound Knife promote tumor cell metastasis and spread?
When focused ultrasound knife was first introduced, there were such concerns among oncologists, but then a lot of basic and clinical studies have confirmed that focused ultrasound knife not only does not promote tumor metastasis, but also can locally close the blood vessels and lymphatic vessels around the tumor to stop its spread.
6.Does focused ultrasound knife treatment have serious toxic side effects?
Focused ultrasound knife treatment is close to “non-invasive”. Patients do not need anesthesia, and the treatment is generally painless (occasionally there is a slight tingling sensation), and there are no systemic symptoms such as drop in white blood cells.
Numerous studies have shown that focused ultrasound knife treatment can greatly enhance the patient’s anti-tumor immune function, which may block the growth of tumors in other areas.
At the same time, it should be noted that the local energy density of focused ultrasound knife is very high, and improper application, such as inappropriate positioning, can lead to consequences such as perforation of the digestive tract and nerve damage. During the treatment of nearly 2000 people in the Focused Ultrasound Knife Center of East China Hospital, there has not been a single case of the above-mentioned serious complications.
7.Will the tumor disappear completely after high energy focused ultrasound knife treatment?
Unlike traditional surgical resection of tumors, Focused Ultrasound Knife treatment applies the principle of “in situ thermal coagulation of tumors”, and the remains of tumors (necrotic tissues) are still in the body after treatment, but the original tumors are completely necrotic and lose the ability of proliferation, invasion and metastasis. Angiography, CT, MRI, ultrasound and PET can confirm that the tumor tissue is necrotic. Since focused ultrasound knife cauterizes and closes the blood vessels around the tumor, it slows down the absorption rate of necrotic tumor tissue. Generally, the necrotic tissues start to shrink in 3 months after treatment, and a few of them may disappear completely, but most of the necrotic tumor tissues may not disappear completely, but only show no growth or shrink significantly.
The inactivated tumor tissues have no toxicity in the body, but can play the role of “tumor vaccine”, which can continuously stimulate the immune system and help to improve the anti-tumor immune function of the body.
8.Some people say that focused ultrasound knife can only work on a small focus and can only treat superficial tumors.
This statement is due to the complete lack of understanding of focused ultrasound knife. The focus of focused ultrasound knife is indeed very small, but this point is only the most basic unit. Under the monitoring of ultrasound, it will keep moving along the tumor (scanning) and finally cover the whole tumor, which is the “conformal treatment”. At present, only surgery and focused ultrasound knife can achieve the real “conformal treatment”.
The characteristic of focused ultrasound knife is that it can treat deep tumors, but it is easy to burn the skin when treating tumors that are too superficial.
9.Is high-energy focused ultrasound knife and laser knife the same thing?
No, laser can also be focused, but it has no penetrating characteristics and is only used to treat superficial tumors (such as skin tumors).
10.What is the difference between high-energy focused ultrasound knife and x-knife or gamma knife?
X-knife and γ-knife are radiotherapy.
11.Focused ultrasound knife and traditional thermal therapy
The principle of traditional thermotherapy, i.e. warming therapy, is to heat up the tumor tissue to 42,5℃ and accumulate nearly ten hours, the tumor cells will undergo a series of biological effects (such as intracellular acidosis, protein denaturation, apoptosis, etc.) and die in large quantities.
Since uniform heating and non-destructive temperature measurement are always difficult to solve, and some tumor cells have obvious heat resistance, thus the promotion of thermo-therapy in clinical practice is greatly limited.
Focused ultrasound knife is also in the category of thermal therapy in a broad sense, but it has completely surpassed the traditional thermal therapy in terms of technology, mechanism, operability and effectiveness. Focused ultrasound knife can completely cauterize the tumor point by point along the tumor boundary, causing coagulative necrosis of the tumor tissue – the treatment of tumor becomes easy, safe and intuitive.
12.Focused ultrasonic knife and surgical resection
Surgical resection of tumor is still the main means of tumor treatment at present.
Surgical resection can achieve radical cure for early stage tumors, but for middle and late stage tumor cases, even if the scope of resection is expanded, the tumor cannot be cured; and at this time, the serious trauma and complications brought by surgery, as well as the damage of anti-tumor immune function by surgery greatly weaken the anti-tumor ability of the body, thus stimulating the growth of residual tumors.
Focused ultrasound knife is an extension and expansion of the scalpel. In many tumor cases, focused ultrasound knife can achieve the same local curative effect as surgical resection through high temperature coagulation, but its damage to the body is negligible; for patients with intermediate and advanced tumors, focused ultrasound knife treatment can stimulate the anti-tumor immune function of the body, so that the growth of other parts of the tumor is inhibited and the tumor recurrence rate is significantly reduced.
For a few tumors, such as gastric cancer, focused ultrasound knife treatment cannot achieve regional lymphatic tissue clearance like surgery, and therefore theoretically cannot reach the local treatment standard of surgery. For such patients, unless they are really advanced or their systemic conditions cannot tolerate radical surgery, focused ultrasound knife is not the first choice of treatment.
13. What is the main limitation of high energy focused ultrasound knife?
Since ultrasound cannot pass through bone tissue and air-containing tissue, it cannot treat lung cancer and cranial tumors, and some right lobe liver tumors cannot be completely treated because they are blocked by ribs. Therefore, compared with radiotherapy, focused ultrasound knife treats fewer diseases, but within the scope of its treatable indications, it shows incomparable superiority.
Second, high energy focused ultrasound knife? Application
1.Applications
Solid tumors in the abdominopelvic cavity that can be detected by B-ultrasound and have sufficient access to the acoustic beam, and the depth of the tumor must be at least 1 cm.
Disease:
Can be treated:
Reason/Remarks:
Thyroid tumor.
Cannot.
Too superficial, may burn skin.
Lung cancer.
Cannot.
Air-containing tissue, ultrasound cannot pass through.
Colon cancer.
Most cannot.
Large volume and extra-intestinal invasion can be treated.
Skin tumors.
Unable.
Cephalic/head and face tumors.
Not possible.
Ultrasound cannot pass through the skull.
Bone metastases.
Cannot.
Pancreatic cancer.
Can.
Severe jaundice should be preceded by yellowness reduction.
Left hepatocellular carcinoma.
Yes.
The ultrasound image is clear and there is no obstruction of the incident channel.
Right hepatocellular carcinoma.
Not necessarily.
Higher tumors may be obstructed by the rib cage.
Prostate cancer.
Yes.
Catheterization must be retained.
Uterine fibroids.
Yes.
Diameter <6cm, number <3.
Ovarian cancer.
Yes.
Especially suitable for postoperative recurrence.
Retroperitoneal metastatic tumor.
Yes.
Ultrasound image is clear.
Gastric cancer.
Yes/No.
Treatment may be attempted for those who can be localized by ultrasound.
Rectal cancer (recurrent).
Can.
Breast cancer.
Can.
For patients who refuse surgery.
Bladder cancer (recurrence).
Can.
Treatment may be attempted for those who can be localized by ultrasound.
Osteosarcoma, soft tissue tumors.
Can.
Renal cancer or adrenal tumors.
Not necessarily.
May be obstructed by the rib cage.
Prostatic hyperplasia.
Can.
Catheterization must be left in place for 2 weeks.
In conclusion, focused ultrasound knife treatment should be preceded by ultrasound examination, preferably by a professional physician of our center (our center provides free pre- and post-treatment ultrasound examination), in order to clarify the location, size, shape and adjacent relationship of the tumor, and to determine whether it can be treated and the treatment plan.
Determine the treatment plan
Film reading
Ultrasound examination
Definite diagnosis
Bring medical history information to the ultrasound knife center
2.What diseases are most commonly treated with focused ultrasound knife?
Among the cases treated in our center, the most common ones are pancreatic cancer, liver cancer, retroperitoneal metastasis of gastrointestinal tumors, uterine fibroids (adenomyosis), and recurrent tumors.
3.In addition to directly killing tumor cells, what other effects might the focused ultrasound knife have?
(1) Closure of blood vessels and lymphatic vessels around the tumor to stop the spread and metastasis of the tumor.
(2) To close the nerves around the tumor and play a pain-relieving role.
(3) Relieving obstruction of ducts caused by occupancy (e.g. intestines, lymphatic vessels or ureters).
(4) Improving the body’s anti-tumor immune function.
(5) Improving the quality of life.
4. How to select cases and will it conflict with other treatments?
(1) For tumors that cannot be removed surgically and patients with poor general condition, advanced age or unable to tolerate surgery, there are few effective local treatments available at this time, and focused ultrasound knife should be preferred because of its non-destructive, efficient, safe and repeatable characteristics.
(2) For patients who are particularly afraid of surgery or refuse to remove specific organs (e.g., uterus, limbs, breast), focused ultrasound knife is a wise choice.
(3) For tumor patients who wish to undergo surgery, preoperative focused ultrasound knife treatment can coagulate the tumor and reduce the metastatic spread of the tumor before, during and after surgery, and may also reduce intraoperative bleeding, thus complementing surgical treatment and improving overall efficacy.
(4) For patients in radiotherapy and chemotherapy, focused ultrasound knife treatment can produce synergistic and sensitizing effects with radiotherapy and chemotherapy, thus improving the efficacy of the former by 5-8 times.
In short, tumor treatment has broken through the scope of a single discipline, and the current internationally recognized tumor treatment model is comprehensive treatment. Focused ultrasound knife can perfectly combine with surgery, radiotherapy, chemotherapy and even Chinese medicine and immunotherapy to improve the overall efficacy.
5.Can Focused Ultrasound Knife cure tumors at the root?
Under the current medical level, only early-stage tumors have the possibility of radical treatment, and most of the tumors treated by surgery are early-stage tumors.
For early stage tumors, focused ultrasound knife can completely cure them, such as left lobe liver cancer and some breast cancers, and there are many successful cases. Compared with some traditional treatment methods, focused ultrasound knife is still a new technology developed in the last decade. From the viewpoint of medical ethics, we generally do not actively encourage or induce patients to give up surgery and receive focused ultrasound knife treatment alone.
6.What is the efficiency of Focused Ultrasound Knife in treating tumors? Is there any possibility of failure?
The efficiency of some common treatment methods is often much lower than what people expect. Some treatment methods are very traumatic and damage the immune function of the body, but promote the growth and metastasis of tumors.
Although focused ultrasonic knife can theoretically cause complete coagulative necrosis of tumor tissues in the target area, in actual application, some factors interfere with its effect, such as unclear display of tumor, resulting in spending too much time for each positioning, which is not conducive to the accumulation of heat in the tumor; and also such as tumor adjacent to intestinal canal, or the accumulation of gas in the intestine above the tumor, which makes part of ultrasonic reflection. Of course, with the accumulation of experience, some interfering factors may be eliminated, but it is still impossible to achieve 100% success in treatment. Among the patients we have treated, there are indeed a small number of patients who have poor results, as the tumor continues to grow and often requires further additional treatment, and a very small number of patients (often tumors that have metastasized and spread extensively) cannot achieve satisfactory results even with additional treatment.
Focused ultrasound knife is close to non-invasive tumor treatment technology, and the worst result is “ineffective”, which will not produce obvious toxic side effects, and will not promote the development of the disease.
7.What is the depth range of Focused Ultrasound Knife treatment?
The deepest point is 13cm from the epidermis, and the shallowest point is 1cm from the epidermis. Therefore, lymph nodes metastasized in the head and neck or clavicular area are not suitable for focused ultrasound knife treatment, while part of the peritoneal metastatic nodes are within the treatment range due to the thick abdominal wall tissue.
8.Focused ultrasonic knife treatment times, cost
Several small tumors can be treated at one time, but larger tumors need to be treated in several times (φ5cm tumor: 3~5 times).
Each treatment time (including positioning time) is about 40-60 minutes, and the interval between treatments is 1-4 days, usually not more than 1 week.