1.The expression and clinical significance of viral macrophage inflammatory protein vMIP-Ⅰ and vMIP-Ⅱ in Kapsi's sarcoma patients
Xiaodong WANG ; Han JIANG ; Ping HOU ; Dalihan · DUOLAND ; Haojia LUO ; Ping MA ; Ablize · PALIHAN
Chinese Journal of Experimental and Clinical Virology 2015;29(5):421-424
Objective To observe the expression in sarcoma tissue,blood,salivaand urine of KSHV-encoded virus macrophage inflammatory protein vMIP-Ⅰ,vMIP-Ⅱ.Methods Genomic DNA was extracted from samples in 8 classic Kapsi' s sarcoma patients of Xinjiang,vMIP-Ⅰ and vMIP-Ⅱ gene were amplified by PCR.Results Genomic DNA were detected from sarcoma tissue,blood,saliva and urine of 8 classic Kapsi' s sarcoma patients,while vMIP-Ⅰ and vMIP-Ⅱ were amplified from all tissue samples,but the expression of vMIP-Ⅰ and vMIP-Ⅱ in blood,saliva and urine was negtive.Conclusions There is special expression of vMIP-Ⅰ and vMIP-Ⅱ in Kapsi' s sarcoma tissue.It provides a preliminary basis for further study of the mechanism of angiogenesis Kaposi's sarcoma.
2.Effects of gantry acceleration limitations on VMAT plans
Haojia ZHANG ; Shihu YOU ; Haijie JIN ; Yi ZHANG ; Yuanqiang LUO ; Zhiyong WANG ; Congfeng XU ; Jiaying GAN ; Yinxiang HU
Chinese Journal of Radiological Medicine and Protection 2021;41(9):659-664
Objective:To study the effects of gantry acceleration limitations of a linear accelerator (linac) on the dosimetry of volumetric modulated arc therapy (VMAT) plans, machine efficiency, and dose verification result of VMAT plans and to explore the optimal selection of gantry motion models in the Pinnacle treatment planning system.Methods:Ten cases of nasopharyngeal carcinoma, non-small cell lung cancer, sigmoid adenocarcinoma with retroperitoneal lymph node metastasis, and invasive ductal carcinoma of the breast were each selected for this study. Then two models were set up in the Pinnacle v9.10 treatment planning system, namely the one allowing gantry acceleration and the one limiting gantry acceleration. The same field arrangement, optimized target parameters, and optimized weights of VMAT plans were adopted in the two models, in order to analyze the dosimetric variations in targets and organs at risk (OARs) and compare the differences in treatment time and gamma passing rates.Results:The treatment time of the enrolled patients under the model allowing gantry acceleration was significantly lower than that of the patients under the model limiting gantry acceleration was adopted ( t=-6.751, -0.209, -19.523, -28.999; P< 0.05) and decreased by 15.27%, 18.07%, 19.71%, and 28.75%, respectively. Meanwhile, the conformity and uniformity of target areas were affected, while there was no statistical significance in the gamma passing rates in the validation of VMAT plans ( P>0.05). For the cases of nasopharyngeal carcinoma (NPC), the maximum dose to brainstem PRV increased by 1.25%. For the cases of lung cancer, the maximum dose to the spinal cord and lung V20 increased by 1.19% and 1.21%, respectively, while lung V5 decreased by 1.21%. For the cases of sigmoid adenocarcinoma with retroperitoneal lymph node metastasis, the mean doses to bilateral kidneys, livers, small intestine, and colon all increased. For the cases of breast cancer, lung V10 on the opposite side of cancer increased by 1.66% and the mean dose to the lungs on the same side of cancer decreased by 7.45%. Conclusions:The model allowing gantry acceleration allows the treatment time to be significantly shortened and the treatment efficiency improved. Although this model had the shortcomings such as affecting the conformity and uniformity of target areas to a certain extent and increasing the doses to some OARs, clinical requirements for dosimetry were still met. Therefore, it is recommended to use the model allowing gantry acceleration in the Pinnacle planning system.
3.Monte Carlo simulation-based analysis of cell damage by 9C-ion decay products
Yi ZHANG ; Shihu YOU ; Yuanqiang LUO ; Zhiyong WANG ; Congfeng XU ; Haijie JIN ; Haojia ZHANG ; Wei HONG ; Jiaying GAN ; Yinxiang HU
Chinese Journal of Radiological Medicine and Protection 2024;44(5):361-366
Objective:To explore the radiological damage to cells induced by the delayed particles of 9C-ions for heavy ion therapy, as well as the microdosimetric distribution and biological effects of these particles on a single model of V79 Chinese hamster lung cells. Methods:The Monte Carlo program was employed to simulate the endonuclear absorbed doses of α particles with various energies (3-10 MeV) transported in cells (cell radius RC = 10 μm, nucleus radius RN = 5 μm). Then, the result were compared with the S values ( SN←N, SN←Cy, and SN←CS) derived using the medical internal radiation dose (MIRD) method to demonstrate the feasibility of Monte Carlo simulations. Finally, the energy deposition of the delayed particles of 9C-ions generated at three sites (i.e., on the surface and in the cytoplasm and nucleus of the V79 cell model) during their transport in targets was simulated, and the result ing cell surviving fraction was analyzed. Results:Monte Carlo and MIRD method yielded differences in S values of 1.91%-4.95% for SN←N (nucleus to nucleus), 1.48%-5.11% for SN←Cy (cytoplasm to nucleus), and -1.99% to 0.80% for SN←CS(surface to nucleus), indicating highly consistent S values derived using both method(differences < 6%). When a 9C-ion decayed on the surface of the V79 cell model and the produced secondary particles entered the cell, the average endonuclear absorbed dose was 10 -2 Gy orders of magnitude, with a cell surviving fraction of about 88%. In the case where decay occurred in the cytoplasm, the cell surviving fraction was about 80%. However, when the 9C ion decayed in the nucleus, α particles had short ranges and deposited most of their energy in the cell (mean endonuclear absorbed dose: 0.1 Gy). In this case, severe cell damage was induced, with the cell surviving fraction reducing to about 53%. Conclusions:9C-ions emit secondary charged particles due to decay, among which α particles cause great damage to cells when entering the nucleus and trigger evident biological effects.