The precision radiotherapy adopts the accurate fixation,immobilization,spacial orientation and 3-dimensional calculation & display methods.On three-dimensional direction,stereotactic conformal or intensity modulated radiation therapy with conventional or non-conventional segmentation method is used.So the high dose area is identical with the target on three-dimensional and the dose intensity modulated in the target.It aims to decrease or not increase the radiation dose in the normal organs and tissues around the target when increasing the radiation dose in the tumor target.The technology can improve the partial control rate and the living quality of the patients.

The cuniform gene of arbitrary angle cuniform board is computed through electric standard cuniform board.

Objective To apply lead block technology to the interdiction of X-ray destroy from linear accelerator to normal tissues and sensitive organs so as to treat large fields and irregular malignant lymphoma.Methods The steps were as follows:(1)immobilizing patients;(2)simulator photographing;(3)sketching targets;(4)tailoring lead block;(5)validating lead block.Results Problems of large fields and more targets were solved in radiotherapy for malignant lymphoma patients.Conclusion Based on clinical practice,new methods was found for realizing large irregular radiation fields.

Objective To investigate and carry out the function of the lead block validating instrument in the radiotherapy. Methods Based on clinical practice and the principle comparative steady STD and SAD of linear accelerator, the function of lead block validating instrument was developed in reason. Results The working quality and efficiency are greatly improved. Conclusion Not only the criterion extent of founded lead block and the proof of every kinds spume blocks in three-dimensional conformal radiotherapy and integer block radiotherapy and electron radiotherapy, but also the shadow tray centers and center reticle can be validated by the lead block validating instrument.

Objective To explore the methods and effects of body fractionated stereotactic radiotherapy(X-knife) in the treatment of lung metastases.Methods There were 50 cases with lung metastases were treated by fractionated stereotactic radiotherapy using CT orientation and WiMRT model body X-knife.The diameter of the metastases was 1.0cm-5.0cm.The linear accelerator was 6Mv X-ray.The dose per fraction was 5-12Gy,and the total prescribed dose was 30-52Gy at the margin of the PTV enveloped by 90% insodose curve.Results The metastases complete regression was found 21 fo-cus(18.3%)in CT image,partial regression in 70 focus(60.9%),and the overall effective rate was 79.1%.The effective rate for the focus with diameter less than 3cm was 88.5%,and 59.4% equal or more than 3cm,there was significan differ-ence(P

The quality assurance method for the medical linear accelerator of large-scale radiotherapy equipment is introduced,whose periodic detection and adjustment are discussed.

Objective To introduce the clinical design of the portable and moveable laser light for simulation immobilization.Methods According to the theory of the laser immobilization system,the setting is designed by using current material,such as a ruler of ?-shape and pillar-shape laser light etc.After installation and adjustment,it is used in clinic.Results Patient can be immobilized by CT and this setting.Being simple to operate and convenient to use,this setting can act for the expensive laser position system.Conclusion The material and creation of this setting are rougher,so it needs improvement to insure the accuracy of position.

Objective To discuss the three-dimensional conformal radiotherapy(3D-CRT) plan for pancreatic tumors.Methods The 3D-CRT plan of 30 cases of primary pancreatic cancer were designed according to the request of the doctors for PTV and the restricted receiving dose of the peripheral normal sensitive organs.The best plan was chosen referring the dose-volume histogram.Results By using ICRU dose reference point(the central point of target)as theunitary dose,95% dose line could be surrounded above 95% of the PTV.Conclusion The focus in different localization can be treated with different design in treating the pancreatic tumors.The reaction to radiotherapy is directly influenced by the volume and dosage of radiation to the normal hepatic tissues.

Objective To observe the effect of Yiqi Huexue Recipe on the expression of TGF-β1 and TNF-α on serum and lung of rots with radiation-induced lung injury in different radiation time,and discuss the preventative and curative effect and mechanisms of Yiqi Huoxue Recipe.Methods 66 Wistar rats were randomly allocated into irradiation with Yiqi Huoxue Recipe-treated group(A group)irradiation group(B group),and normal control group(C group).The first two groups were irradiated at right hemithorax with a dose of 30 Gy/6 fractions(in 6 weeks).The levels of TGF-β1,and TNF-α on rat serum and lung were measured by ELISA and immunohistochemistry at the end of the 4th,6th,8th,12th,and 26th week after the first irradiation.Results TGF-β1,and TNF-α level on rats serum and lung in irradiation group showed an increase from the 4th week after the first irradiation,peaking at the 12th week,and descending at the 26th week.In A group,the levels of TGF-β1 and TNF-α were significantly lower from the 4th week than those of B group.Conclusions Yiqi Huoxue Recipe could inhibit the excretion of TGF-β1,and TNF-α and might play an important role in the prevention and curation of radiation-induced lung injury,which might be related to inhibiting the expression of TGF-β1 and TNF-α.

Objective To investigate the expression of suppressor of cytokine signaling genes (SOCSs) and JAKs mRNA in the acute myloid leukemia(AML) patients. Methods The expression of SOCSs and JAKs mRNA as well as TYK2 in AML patients and healthy adults as normal contrals (NC) was measured with RT-PCR. Results The expression of SOCS 1,4,5 and 7 in AML patients was lower than those in normal control and AML with remis-sion (P<0.01),but the expression of SOCS 3 and 6 was higher than those in normal control and remission AML(P<0.01),however there was no significant difference in SOC2 between groups. The expressions of JAK2 ,JAK3 and TYK2 in AML were significantly higher than those in patients with remission and normal control(P<0.05). The ex-pression of JAK1 mRNA in relapsed AML was higher than that in normal control group(P<0.05),but the latter has no statistical significance between beginning treatment and normal group(P>0.05). Conclusion The deletion and degradion of SOCS 1,4,5 and 7 present in AML patients and JAKs expression is significantly increased, suggesting that both of them may co-participate in the pathogenesis of AML.