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 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 explore the clinical value of 68Ga-pentixafor PET/CT targeting for CXCR4 in the diagnosis and prognosis evaluation of primary aldosteronism (PA). Methods:Retrospective analysis was performed on information of 72 patients diagnosed with PA who received operations according to the results of 68Ga-pentixafor PET/CT in our hospital. There were 37 males and 35 females, with the average age of (48.3±9.5) years old. The average lesion diameter was (1.60 ± 0.54)cm. The preoperative systolic and diastolic blood pressure were (177.3 ± 23.9)mmHg and (107.6 ± 13.2)mmHg, respectively. The average preoperative potassium level was (2.62 ± 0.56)mmol/L. The average aldosterone concentration was (17.98 ± 4.66)ng/dl, and the median plasma renin activity was 0.01 (0.01, 0.09) ng/(ml·h). All patients underwent 68Ga-pentixafor PET/CT examination, which lead to the decision of surgical strategies. For those patients with single lesion, multiple lesions in one side or positive lesion in one side but negative in the opposite side, surgical resection of the positive side lesion or total adrenalectomy was considered. For those patients with bilateral positive lesions, surgical resection of the side with more significant positive lesions or total adrenalectomy was considered. For those with negative multiple lesions, the surgical strategy was designed according to the results of CT examination or AVS. The positive rate of 68Ga-pentixafor PET/CT and its relationship with the clinical characteristics and prognosis of patients were analyzed. Results:The results of 68Ga-pentixafor PET/CT were positive in 62 of 72 patients diagnosed with PA (86.1%), and the median SUVmax value was 11.1 (7.1, 16.2). The SUVmax value was positively correlated with the maximum diameter of adrenal lesion ( r=0.468) and negatively correlated with blood potassium levels ( r=-0.437), while not significantly correlated with other clinical characteristics. The positive rate of adenoma by 68Ga-pentixafor PET/CT was higher than that of nodular hyperplasia [90.5%(57/63) vs. 55.6%(5/9), P=0.018], and the SUVmax value in adenoma was also higher than that in nodular hyperplasia [11.9(7.8, 16.2) vs. 4.3(3.4, 11.3), P=0.022]. 32 cases were cured after operations, and 37 cases were improved. And 3 cases were not cured. The SUVmax value of lesions in the cured patients was higher than that in the improved patients [15.4(8.1, 22.7) vs. 10.1(6.8, 13.3), P=0.013]. Among 59 cases of PA patients with single adrenal lesions, 50 cases represented positive results of 68Ga-pentixafor PET/CT. 23 cases in 50 positive cases were cured and 27 cases were improved after resection of positive lesions. In the 13 PA patients with multiple adrenal lesions who underwent surgery according to the results of 68Ga-pentixafor PET/CT, 12 patients (92.3%) showed postoperative prognosis in line with preoperative expectations. Conclusions:68Ga-pentixafor PET/CT showed high positive rate in the diagnosis of PA, especially for adenoma.The SUVmax value of the adrenal lesion was correlated with the blood potassium level, the size of the lesion and the postoperative prognosis. In addition, 68Ga-pentixafor PET/CT could effectively guide the surgical decision of PA.