The gamma knife dose selection is effective in the treatment of lesions without causing obvious complications. That is to say, it can not on
The gamma knife dose selection is effective in the treatment of lesions without causing obvious complications. That is to say, it can not only damage the surrounding normal tissue but also give the effective radiation dose.
In the study of radiation dose, the dose response curve was used to evaluate the relationship between the effect and complications. Most of the current prescription dose of gamma knife radiosurgery implementation from clinical experience accumulated for a long time, there is no uniform standard. However, the following factors should be taken into account when giving treatment dose:
1, the nature of lesions
The pathological nature of lesions of different gamma knife reactions are different, the implementation of the surrounding benign tumor of low dosage, malignant tumors need higher radiation dose to control tumor growth. The closure rate of cerebral arteriovenous malformation is directly dependent on the dose of radiation, the peripheral dose is high, the closure of cerebral arteriovenous malformation is rapid, and the rate of closure is high.
2, lesion volume
Directly related to lesion volume and side effects after gamma knife treatment in general, the lesion volume is small, in the implementation of prescription dose range, can choose high dose; the lesion volume, the implementation of the corresponding lower dose treatment.
3, the location of lesions
Lesions in the brain tissue of non functional, even after gamma knife treatment have some brain injury, patients may not appear clinical symptoms, these sites can choose high dose prescription dose range. However, if the lesion is close to an important functional area or can only tolerate a low dose of cranial nerve, strictly control the radiation dose.
4, measurement planning factors
In the same treatment, the treatment target area contains more normal brain tissue. In the formulation of the treatment plan, try to make the design of isodose curve and the treatment of the lesion is basically the same.
5, cranial nerve and brainstem tolerance dose
The gamma knife treatment, should pay special attention to the radiation of cranial nerve and brainstem by. Safe and tolerated dose of optic nerve and optic chiasma optic tract for safety < tolerated dose of 9Gy facial nerve is less than 13Gy, the tolerance dose of cavernous sinus cranial nerve is less than 15Gy, safe and well tolerated doses to the brain is 12Gy, but when the exposure of the brain stem volume is very small, the radiation doses to the brain can accept 15Gy.