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Proton knife promotes a new era of nerve tumor treatment.
Proton therapy system is the best equipment for treating systemic tumors, which has been put into clinical use in Zibo Wanjie Hospital. More than 200 experts and professors from the medical field of neurooncology in the whole province visited the proton therapy center of Zibo Wanjie Hospital on the spot, and made in-depth discussions on the clinical application of proton knife and other new advances in neurooncology treatment. Zibo Wanjie Hospital was used as a conformal radiotherapy center for tumors. Intracranial nerve tumors have mature treatment methods. Conventional surgery and traditional radiotherapy surgery are generally used to treat intracranial tumors. Human factors and tumor growth sites limit the therapeutic effect. In 2002, Zibo Wanjie Hospital successfully introduced the most advanced proton therapy system in China and established the first proton therapy center in China, which made China's tumor radiotherapy technology reach the world leading level. Proton therapy system has the advantages of high energy, high precision and little side effects. It can shoot tumors in any part of the human body, and it can hit the tumors pertinently, conformal and accurately, and destroy the diseased tissues.
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The Cancer Treatment Center of the University of Texas invested $65.438+$25 million to establish a proton treatment center to treat cancer patients with the most advanced technology, which can treat 3,500 patients with lung cancer, prostate cancer, head and neck cancer and eye cancer every year.
Proton therapy is the most advanced technology in radiotherapy. Different from traditional X-ray radiotherapy, proton rays only release a small amount of energy on the path they pass through, and only release a large amount of energy when they reach the depth of treatment, so radiation has little impact on normal tissues.
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Accelerate the construction of key medical and health projects. Construction of Nanhui, Fengxian Central Hospital, 13 first-aid sub-station (point) and 400 village clinics, guiding municipal high-quality medical resources to support suburban health undertakings, and improving the level of rural medical services in suburbs. Promote the renovation of the outpatient medical technology building of Shanghai Sixth People's Hospital and the emergency building of East China Hospital, and pay close attention to the preliminary work of proton knife project.
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096. Briefly describe the principle of stereotactic radioneurosurgery.
(1) The equipment needed for stereotactic radioneurosurgery to treat diseases includes linear accelerator, γ knife, cyclotron, short-distance remote control afterloading machine, etc. X-ray, γ-ray, electron beam, proton beam, heavy particle beam and isotope used in interstitial radiotherapy are provided by the above device; (2) With the help of high-precision stereotactic instrument, with the participation of CT, MRI, DSA and other imaging technologies, the therapeutic target is accurately located and the target coordinates are determined; (3) using the treatment planning system to determine the treatment plan; (4) The three-dimensional coordinate parameters of the target are converted into the coordinate system of the irradiation device, and the rays are focused on the target by controlling the direction of the incident rays and their running tracks, so as to realize the treatment of the target.
097. Briefly describe the method, scope of application and complications of stereotactic treatment.
In recent years, many new treatment techniques and methods have been derived from stereotactic reflex therapy, such as γ knife and X knife with 60Co or linear accelerator as radiation source; Ion knife with heavy ion accelerator as radiation source; Brachytherapy of tumor interstitial arc cavity with radioisotope as radioactive source: after directional operation, catheter was placed in the lesion site in advance, and then afterloading treatment was carried out; Intraoperative radiotherapy for tumor bed. It can be used for cerebrovascular malformation, some intracranial tumors and functional diseases. The main complications were radiation-induced brain necrosis, edema of brain tissue around the target area, hemorrhage of the focus and neurological dysfunction.
098. Briefly describe the method of stereotactic target destruction.
(1) radio frequency electrothermal injury: 1. Radio frequency electrocoagulation: the electrocoagulation temperature is 60℃-80℃; The size of damaged area is controlled by electrocoagulation time, which is generally 5 s-30 s; 2. induction heating (2) DC electrolysis; (3) Mechanical cutting: the target structure is mechanically cut with a special cutting tool; (4) Drug injection: injecting nerve-destroying drugs, usually alcohol, into the target area; (5) Freezing method: Double-cavity brain needle with liquid nitrogen as coolant; (6) ultrasonic wave; (7) Radioactive injury: 1. Radionuclide implantation in brain; 2. In vitro heavy ion irradiation; 3.γ knife, X knife and other means.
026. Briefly describe the application of interventional radiotherapy in neurosurgery.
1. treatment of cerebral aneurysms: endovascular embolization with a detectable detachable balloon can be performed while the patient is fully awake, and neurological function can be continuously monitored, so that most aneurysms that are difficult to complete in large and medium-sized operations can be treated by this technology; 2. Treatment of cerebral arteriovenous malformations: For the main functional areas and deep cerebral arteriovenous malformations that are difficult to complete, this technique can achieve satisfactory results; 3. Treatment of arterial spasm and arterial stenosis: If the drug treatment of symptomatic vasospasm after subarachnoid hemorrhage does not work, angioplasty can work; 4. preoperative embolization of external carotid artery for meningioma: it can reduce intraoperative bleeding, make the surgical field of vision clear, and it is easy to completely remove the tumor; 5. Selective or superselective intra-arterial infusion of anticancer drugs to treat glioma: this method is superior to intravenous administration, which can reduce systemic reaction, increase local drug concentration and achieve better therapeutic effect; 6. Others: treatment of Galen venous tumor, treatment of spinal vascular malformation, and thrombolytic therapy after cerebral embolism.
062. Briefly describe the principle and general situation of photodynamic therapy for brain tumors.
Some photosensitive substances such as fluorescein, eosin, tetracycline and perylene compounds can be absorbed by malignant tumor cells and accumulated in mitochondria of cytoplasm. The storage capacity can reach 5-20 times that of normal tissues and cells, and the storage time can be as long as 48 hours. Under the irradiation of light, tumor cells containing photosensitive substances lose their vitality due to physical or chemical reactions, thus achieving the purpose of treatment. However, most photosensitive substances cannot pass through the blood-brain barrier, which greatly hinders the role of photodynamic therapy in brain tumors. In recent years, it has been found that hematoporphyrin derivatives treated with acetic acid and sulfuric acid can not only penetrate the blood-brain barrier, but also enter tumor cells. Therefore, using it to treat brain tumors not only has a reliable theoretical basis, but also will greatly improve the curative effect of this therapy.
064. Introduce boron neutron capture therapy.
Boron neutron capture therapy (BNCT) is a therapeutic method to destroy tumor by nuclear reaction in tumor cells. Firstly, the patient was injected with stable isotope 10 boron (10B). After 10B enters the body, it is quickly concentrated in the cells of tumor patients, and then the tumor body is irradiated with high-energy thermal neutrons. After irradiation, 10B absorbs neutrons and becomes 1 1B atoms, which immediately undergo nuclear fission and release α particles. Alpha particles are high-energy transmission density rays, which can effectively kill tumor cells, and are equally effective for hypoxic cells and interphase cells. Alpha particles have a short range, only 10um, which is equivalent to a cell diameter, so they can only kill tumor cells with nuclear reaction and have no effect on surrounding normal cells, thus achieving the purpose of protecting surrounding healthy tissues, and are mainly used for high-grade gliomas.
065. Briefly describe the concept and progress of brachytherapy for brain tumors.
Brachytherapy, named after conventional long-distance radiotherapy, is a radiotherapy method that directly implants radioactive sources into tumors. Include interstitial radiotherapy and intracavitary radiotherapy. In recent years, with the application of CT and MRI, it is more accurate to determine the location, size and shape of tumors. The combination of imaging method, stereotactic and computer can simulate the preoperative isotope dose curve and accurately implement the predetermined radiation dose within the specific tumor boundary. In addition, the improvement of radioactive source implantation methods, such as radioactive source implantation after catheter and intracavitary injection of isotope colloid suspension, can be used to treat tumors with various tissue components, with more indications, especially for brain tumors in deep, functional areas and high malignancy.
066. What are the indications and surgical technical requirements for acoustic neuroma to preserve hearing?
Indication of hearing preservation: 1. Small acoustic neuroma with normal hearing and close to normal hearing; 2.4 cases originated from vestibular nerve and located in the middle of internal auditory canal; 3. When the tumor invading the cerebellopontine angle is less than 65438±0.5cm, when the brainstem auditory evoked potential waveform on the tumor side is basically normal or the thermal response is reduced (suggesting that the tumor probably originated from vestibular nerve), the possibility of hearing preservation is greater, and the acoustic neuroma with a diameter less than 2cm is more likely.
The technical requirements for hearing preservation are: 1. The bone window should be large enough; 2. Release of cerebrospinal fluid reduces intracranial pressure; 3. Grinding the posterior wall of the internal auditory canal (less than12mm); 4. Remove the tumor in the capsule first, and then remove the cell membrane; 5. Application of microscope; 6. Bipolar electrocoagulation; 7. intraoperative monitoring of brainstem auditory evoked potentials: 8. protect the blood supply arteries of the eighth cranial nerve and cochlear nerve.
068. What is the concept of stereotactic radioneurosurgery? What's the difference between neurosurgery and general neurosurgery?
According to the principle of stereotactic radioneurosurgery, the subject of stereotactic radioneurosurgery is called stereotactic radioneurosurgery, which uses a large dose of narrow beam ionizing radiation to accurately focus the irradiation on the intracranial target, thus causing lesion damage and achieving the purpose of treatment. Significantly different from general neurosurgery: 1. No craniotomy, no bleeding, low surgical risk and few postoperative complications; 2. Simple operation, accurate positioning, short course of treatment, little trauma, no need for general anesthesia, blood transfusion and corresponding complications; 3. Patients are not affected by age, physique and repeated operations, and the indications are wide. General neurosurgery is greatly influenced by doctors' experience and surgical skills.
069. What are the application scopes of stereotactic radioneurosurgery?
1. Functional neurosurgical diseases: (1) nausea; (2) Trigeminal neuralgia; (3) intractable psychosis; (4) Extrapyramidal diseases: Parkinson's disease, other basal ganglia diseases such as torsion spasm, spasmodic torticollis and hand and foot peristalsis; (5) epilepsy; (6) Functional pituitary resection is mainly used for malignant pain caused by cancer, which may be related to the inhibition of endocrine function. 2. Non-functional neurosurgical diseases: (1) Intracranial tumors: meningioma, sellar region tumor, pineal region tumor, acoustic neuroma, brain stem tumor, deep brain tumor and intracranial metastasis; (2) Cerebrovascular diseases: arteriovenous malformation, aneurysm, angioreticuloma, cavernous hemangioma of jugular foramen.
070. Briefly describe the biological stage of stereotactic radioneurosurgery.
Stage ⅰ: necrosis stage, when the absorbed dose of target center is 200Gγ, target necrosis, acute degeneration and inflammatory reaction appear in the third and fourth weeks after irradiation; Stage ⅱ: absorption stage, from necrosis stage to one year after irradiation. A large number of cell fragments were absorbed in the necrotic focus, glial scars began to form, and astrocytes proliferated around the necrotic area, which showed chronic inflammatory reaction, vascular congestion, formation of new capillaries and thickening of vascular endothelial cells, which could last for one year or more after irradiation. Stage ⅲ: In the later stage, glial scar was formed after one year of irradiation, a series of early changes disappeared, and cell fragments were completely eliminated, forming a well-defined glial scar.
07 1. What are the indications for stereotactic radiosurgery for arteriovenous malformation?
Generally speaking, the indications of stereotactic neurosurgery in the treatment of cerebral arteriovenous malformation are: 1. The diameter of the lesion is less than 3 cm; 2. Deep brain lesions, especially those located in important functional areas such as brain stem, thalamus or basal ganglia; 3. Patients who are frail or unable to tolerate general anesthesia and craniotomy due to other organ diseases. 4. After craniotomy, there are still abnormal blood vessels; 5. Embolization treatment failed; 6. Patients who refuse craniotomy under general anesthesia.
074. How to choose γ knife and χ knife reasonably in clinic?
1. Gamma knife is the first choice for brain tumors or arteriovenous malformations less than 30mm; 2. Gamma knife is the first choice for deep lesions and lesions located in brain stem; 3. γ knife is the first choice for multiple small lesions, such as multiple gliomas and multiple arteriovenous malformations; 4. γ knife is the first choice for small nasopharyngeal carcinoma; 5. Gamma knife is the first choice for functional neurosurgical diseases; 6. Malignant glioma, unless the volume is small and the upper boundary of MRI is clear, X knife is the first choice; χ-knife is the first choice for lesions with diameter of 7.36mm-50mm; 8. If multiple exposures are required and are greater than 40mm, the χ knife is preferred; 9. It is difficult to locate the neck tumor, and X knife is needed.
075. What are the advantages of gamma knife compared with χ knife?
1.γ knife works reliably; 2. Compared with gamma knife, it has a wider application range, can be extended to skull base, neck, spine and other parts, and is convenient to use; 3. It is suitable for tumors with different sizes and irregularities, cerebrovascular malformations, etc. 4. The aperture range of collimator is above 4mm-50mm; 5. Compared with gamma knife, it has high economic benefit, less investment and low cost; 6. The installation of X-knife stereo positioning device is simpler than that of γ-knife; 7. There are collimators suitable for dynamic and segmented matching; 8. There is no problem that the gamma knife needs to be replaced in five years and radioactive waste needs to be treated.
076. Briefly describe the indications, precautions and main complications of gamma knife therapy for pituitary adenoma.
Indications 1. The distance between pituitary adenoma (especially functional microadenoma) and optic nerve is more than 5 mm; 2. Pituitary adenoma surgery failure or tumor residue or sudden tumor; 3. Old age, poor physical condition and intolerance to surgery; 4. Refusing surgery or not having the conditions for transsphenoidal surgery. In order to obtain the good effect of gamma knife, we should pay attention to the following aspects: 1. Accurate positioning; 2. Choosing appropriate radiation dose, especially the marginal (minimum) dose accepted by tumor, is an important factor; 3. Before treatment, we should know the size of the tumor, the relationship between the tumor and the surrounding structure, and what kind of tumor it is. Practice has proved that ACTH, GH and PRL functional adenomas have good effects.
Main complications: the incidence of pituitary hypofunction is about 10%-33%, which is generally related to inaccurate positioning and excessive dosage. Short-term hypofunction usually occurs 2-6 months after treatment.
077. Briefly describe the diagnostic value of single photon emission CT scanner in the treatment of craniocerebral injury.
SPECT can provide some objective diagnostic basis for the diagnosis of patients with concussion and head trauma syndrome, which can not be determined by objective indicators in clinic at present. However, for patients with brain contusion and intracranial hematoma, SPECT is more sensitive than CT or MRI to some extent, and can find lesions earlier and more than CT, and the scope of lesions found is larger than CT, which can more accurately reflect the clinical situation of patients and predict the progress and prognosis of the disease. Therefore, combining the anatomical information provided by SPECT is helpful to further improve the diagnostic accuracy of craniocerebral injury and guide clinical treatment.
078. Briefly describe the working principle of ultrasonic surgical aspirator.
Ultrasonic surgical aspirator (CUSA) uses a magnetically controlled ultrasonic oscillator to convert electrical energy into mechanical motion, that is, by changing the current of electromagnetic field, it generates 23,000 vibrations per second. This ultra-high-speed vibration is amplified by the connector and transmitted to the surgical probe (titanium tube) to make it move longitudinally. The probe contacts the tumor tissue and smashes it. At the same time, a proper amount of normal saline overflowed around the probe, emulsified with tumor debris and attracted by the suction device on the probe. It can be seen that the ultrasonic surgical aspirator has three functions: oscillation crushing, washing emulsification and suction.
079. Introduce the application of laser in neurosurgery.
1. Intracranial tumors and intraspinal tumors: CO2 laser surgery is available. Low-power (1w-5w) unfocused light was used to coagulate the tumor cell membrane and coagulate the surface blood vessels. Then the tumor cell membrane was excised with a high power (5w- 100w) beam, and finally the tumor cell membrane and small pieces were excised gradually with a low power (1w- 10w) beam. Laser resection of tumor is more thorough, less bleeding, aseptic, accurate and less damage to surrounding tissues. Because blood vessels and lymphatic vessels have been blocked, tumor cells can be prevented from spreading. 2. Cerebrovascular diseases: Laser causes thrombosis in aneurysm, but it has little effect on the parent artery and its adjacent perforating branches, and laser can also coagulate arteriovenous malformation; 3. Functional neurosurgery: treating chronic pain caused by various reasons and controlling trigeminal neuralgia, vascular headache and tension headache; 4. Microvascular anastomosis.
080. Briefly describe the treatment progress of brain tumors.
1. Skull base surgery, which is characterized by large bone flap craniotomy and full exposure, is maturing: the improvement of microsurgery technology and the development of neuroimaging and neuroradiology promote the development of skull base surgery, including brain stem tumors. The monitoring of brainstem evoked potential, the application of laser and the total tumor resection rate have been greatly improved, and the operative mortality and disability rate have been significantly reduced. 2. The rise of minimally invasive neurosurgery: the rapid development of neuroendoscope technology, stereotactic surgery and endoscope-assisted neurosurgery has made the operation less traumatic, less reactive and better; 3. Navigation technology has become a masterpiece of neurosurgical instruments: with the help of this system, intracranial lesions can be accurately located, the best surgical approach and the best surgical scheme can be selected, and the damage of normal tissues and important structures can be reduced or avoided; 4. The genetic engineering of glioma has shown a bright spot: the development of molecular biology and genetic engineering technology provides new means and ideas for the understanding and treatment of the pathogenesis of neurosurgical diseases.
08 1. Briefly describe the present situation and matters needing attention in microsurgical treatment of brain stem tumors.
Status: 1. The forbidden area of operation was broken: the brain stem division was awakened, and the respiratory and circulatory center was regarded as the forbidden area of operation, which was broken from the 1990 s; 2. China is at the leading level in the world.
Note: 1. Preoperative positioning should be accurate; 2. The design of surgical approach should be reasonable; 3. Microsurgery must be performed; 4. Close observation of vital signs and neurophysiological monitoring during operation; 5. The tumor should be removed from the part closest to the brain stem surface, and the operation should be gentle and accurate; 6. When operating 4 mm above and below the medulla oblongata, be highly alert to respiratory disorders; 7. Close monitoring in ICU after operation; 8. Actively prevent postoperative respiratory disorders and stress ulcers, and use a ventilator to assist breathing when necessary.
084. What is a cell knife? Why has cell knife become a popular therapy for Parkinson's disease (PD) in recent years?
The so-called cell knife is to use stereotactic technology to record the target electrical signal with microelectrode extracellular recording electrophysiological technology on the basis of CT and MRI anatomical positioning, so as to realize functional positioning and then carry out radio frequency destruction. Cell knife makes the surgical location more accurate, safe and less complications. Stereotactic surgery for Parkinson's disease began in the 1940s, mainly using pallidotomy and thalamus destruction. Until the 1960s, stereotactic surgery was still an important method to treat Parkinson's disease with good results. Later it was ignored because of the appearance of levodopa. The reason for its popularity again in recent years is: 1. After long-term use of levodopa, the drug effect decreases and serious side effects appear; 2. 1- methyl-phenyl-tetrahydropyridine (MPTP) animal experiment suggested that PD caused slow movement, which may be caused by abnormal discharge of globus pallidus cells. 3. The development of imaging technology (CT, MRI) and microelectrode technology makes the target location more accurate and the operation safer.
085. What are the surgical indications for treating Parkinson's disease with cell knife?
1. First, the patient must be diagnosed as primary PD with no damage to cerebellum and pyramidal tract system, and the possibility of secondary Parkinson's disease and PD superposition syndrome should be ruled out; 2. Patients must receive comprehensive and complete drug treatment (mainly levodopa preparation), which has obvious curative effect on levodopa, but the curative effect is obviously reduced, and there are side effects such as symptom fluctuation (drug powder or conversion phenomenon) and/or dyskinesia; 3. The patient's self-care ability has obviously decreased, and his condition is moderate or severe, with HOHEN and HAHR above grade 3; 4. No obvious dementia and mental symptoms, no serious brain atrophy by CT scan or MRI; 5. The selected patients can cooperate with doctors well during the operation.