ONKOCET Ltd. has exhibited the devices from its portfolio on the MEDTEC UK exhibition in Birmingham, April 2011 through our partner Medical & Partners.
Development of Stereotactic Radiotherapy Technology
In recent years, with the application and development of CT, MRI and PET scanner, the image diagnosis technology of human body has been developed greatly. Human beings have obtained further understanding and cognition of body tissues and intracranial fine structure and complex functions. The early diagnosis detectable rate and abnormal tissue localization precision of body tumor, intracrancial tumor, arteriovenous malformation, and nerve system disease has been improved greatly. The development and utilization of various new stereotactic devices and computer software technology have provided more perfect method for diagnosis and treatment intracranial malfunction, important tissue and organ disease. Up to the eighties of 20th century, in tune with the trend of operation miniaturization, closed loop, and computerization, the stereotactic radiotherapy which regards stereotactic technology as the means and high-energy radial irradiation as the treatment method has been developed very quickly. Stereotactic radiotherapy has many aspects of characteristics, such as precise treatment, simple operation, and non-invasion. Its rise and development is a trans-century revolution in treatment medicine field.
According to stereotactic principle, stereotactic radiotherapy selectively determines targets of normal tissues of abnormal tissues in body and skull to put focus on the target precisely and destroy the target to achieve the treatment purpose. Intracranial target area is usually small and the localization and target planning is relatively strict. According to the size of target and the type of tissues, single focus irradiation treatment or multi foci irradiation treatment can be used. Before the treatment, the dose distribution can be made as conformal as possible to the target with treatment planning. The radiation is expected to be delivered to the target with the surrounding normal tissue spared. Stereotactic radiotherapy can avoid the danger of post-operation hemorrhage, infection, and damaging intracranial important organs that is caused by opening skull operation and general surgical removal. It also can implement effective treatment to tumor or vessel malformation in the deep part of brain, the body (such as internal organ), and esophagus. It established a new radiotherapy method without opening cranium, opening hole, blood, and pain. After the treatment, although ‘target’ still exists from the anatomical images, actually all the tumor cells have become necrosed in solid and the volume will not increase any more. By later stage, all the tumor tissues will be replaced by neuroglial scar tissue and absorbed partially or totally. The patient’s survival time will be lengthened.
Stereotactic radiotherapy is quite different from the traditional radiotherapy. The latter utilizes the sensitiveness of tumor tissue to radioactive rays to treat the disease. The target dosage is greatly smaller than the maximum absorbed dosage of the body surface. The localization precision of equipment is also far lower than the demand of stereotactic radiotherapy equipment. The additional radiation dosage received by the patient’s normal tissues is large, and the clinical radioactive symptom such as alopecia, skin burned often happens. The complicating disease and sequelae after treatment is very relatively serious and the patient’s survival time is within five years. By utilizing vernier focusing of radioactive rays, stereotactic radiotherapy can make the dosage of target far more than the absorbed dosage of healthy tissues. The complicating disease and sequelae is lighter and the patient’s survival time is longer (there are patients who has survived for 20 years).
Whole-Body Stereotactic Gamma Radiotheraphy System (SGS-I) developed by Shenzhen Hype Technology Incorporation has been successfully installed and been brought into clinical operation. The valuable experience obtained provides good foundation for later producing and extended use.
All the stereotactic radiotherapy equipments (gamma knives, Stereotactic Gamma System, X knives, proton knives, and BNCT) utilize high-energy beams to implement the treatment. In the view of physicists, radiotherapy is essentially a process of producing radiobiological effect. In this process, energy is shaped well and is transferred to small-size body tissues. And thus influence the structure and function of tissues that are selected as the target area, induce corresponding physics, chemistry, and biological effect to enable us obtain expected treatment result.
In the process of stereotactic radiotherapy, selection of target is not restricted and the size of target tissues can be very small or very big, especially body tumor whose diameter can be more than 10cm. Stereotactic radiotherapy selectively irradiate these target tissues, while the surrounding normal tissues will be damaged very little.
At present, with the development of stereotactic radiotherapy technology and the invention of gamma knives, SGS, and body X knives, implementing stereotactic radiotherapy to the whole-body tissues and organs of patients is gradually widely used in clinic, which has brought greater hope to the recovery and cure of patients.