Objective To observe changes of plain MR T1WI signal intensity of dentate nucleus in nasopharyngeal carcinoma patients after radiotherapy and multiple times of intravenous injection of gadolinium-based contrast agent(...Objective To observe changes of plain MR T1WI signal intensity of dentate nucleus in nasopharyngeal carcinoma patients after radiotherapy and multiple times of intravenous injection of gadolinium-based contrast agent(GBCA).Methods Fifty patients with pathologically confirmed nasopharyngeal carcinoma and received intensity-modulated radiotherapy were retrospectively enrolled as the nasopharyngeal carcinoma group,and 50 patients with other malignant tumors and without history of brain radiotherapy were retrospectively enrolled as the control group.All patients received yearly GBCA enhanced MR examinations for the nasopharynx or the head.T1WI signal intensities of the dentate nucleus and the pons on same plane were measured based on images in the year of confirmed diagnosis(recorded as the first year)and in the second to the fifth years.T1WI signal intensity ratio of year i(ranging from 1 to 5)was calculated with values of dentate nucleus divided by values of the pons(ΔSI i),while the percentage of relative changes of year j(ranging from 2 to 5)was calculated withΔSI j compared toΔSI 1(Rchange j).The values of these two parameters were compared,and the correlation ofΔSI and GBCA injection year-time was evaluated within each group.Results No significant difference of gender,age norΔSI 1 was found between groups(all P>0.05).The second to the fifth yearΔSI and Rchange in nasopharyngeal carcinoma group were all higher than those in control group(all P<0.05).Within both groups,ΔSI was positively correlated with GBCA injection year-time(both P<0.05).Conclusion Patients with nasopharyngeal carcinoma who underwent radiotherapy and multiple times of intravenous injection of GBCA tended to be found with gradually worsening GBCA deposition in dentate nucleus,for which radiotherapy might be a risk factor.展开更多
To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcu...To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.展开更多
Objective： Conventional external beam irradiation techniques for nasopharyngeal carcinoma have limitations, and improving external beam irradiation techniques is needed to enhance the curative rate. This study was de...Objective： Conventional external beam irradiation techniques for nasopharyngeal carcinoma have limitations, and improving external beam irradiation techniques is needed to enhance the curative rate. This study was designed to cvaluate the difference in dose distribution of three dimensional conformal radiotherapy （3D CRT） and conventional treatment plan in early untreated nasopharyngeal carcinoma using a three dimensional treatment planning system. Methods： Twenty-two patients with early untreated nasopharyngeal carcinoma were selected. Conventional and 3D CRT plans were made for each of them and compared with respect to target volume coverage （V95）,normal tissue sparing （D50, D33 and D5, etc）, normal tissue complication probability （NTCP）. Results： The average volumetric dose comparison indicated that the V95 of PTVnx70 were 98.22% and 99.99% （P=0.06）, and PTVnd60, 98.41% and 99.63% （P=1.00）, PTV,x60, 98.44% and 99.98% （P=0.03）, PTVnx50, 98.85% and 99.63% （P=0.02） in conventional and 3DCRT treatment plans respectively. With respect to normal tissue sparing, the average D50 of unilateral parotid glands were 51.91 Gy and 64.30 Gy （P=0.00） respectively, and the unilateral temporomandibular joints, 49.98 Gy and 64.47 Gy （P=0.00）, the Dlcc of spinal cords, 44.98 Gy and 48.09 Gy （P=0.00） in 3D CRT and conventional plans. Conclusion： Though only a little bit better dose coverage of target volume in subclinical lesion region was reached in 3D CRT plans, it spared more normal tissues e.g. parotid glands and temporomandibular joints etc and decreased their NTCP while it got the similar dose distribution in target volumes as conventional plans did for these early nasopharyngeal carcinoma cases.展开更多
文摘Objective To observe changes of plain MR T1WI signal intensity of dentate nucleus in nasopharyngeal carcinoma patients after radiotherapy and multiple times of intravenous injection of gadolinium-based contrast agent(GBCA).Methods Fifty patients with pathologically confirmed nasopharyngeal carcinoma and received intensity-modulated radiotherapy were retrospectively enrolled as the nasopharyngeal carcinoma group,and 50 patients with other malignant tumors and without history of brain radiotherapy were retrospectively enrolled as the control group.All patients received yearly GBCA enhanced MR examinations for the nasopharynx or the head.T1WI signal intensities of the dentate nucleus and the pons on same plane were measured based on images in the year of confirmed diagnosis(recorded as the first year)and in the second to the fifth years.T1WI signal intensity ratio of year i(ranging from 1 to 5)was calculated with values of dentate nucleus divided by values of the pons(ΔSI i),while the percentage of relative changes of year j(ranging from 2 to 5)was calculated withΔSI j compared toΔSI 1(Rchange j).The values of these two parameters were compared,and the correlation ofΔSI and GBCA injection year-time was evaluated within each group.Results No significant difference of gender,age norΔSI 1 was found between groups(all P>0.05).The second to the fifth yearΔSI and Rchange in nasopharyngeal carcinoma group were all higher than those in control group(all P<0.05).Within both groups,ΔSI was positively correlated with GBCA injection year-time(both P<0.05).Conclusion Patients with nasopharyngeal carcinoma who underwent radiotherapy and multiple times of intravenous injection of GBCA tended to be found with gradually worsening GBCA deposition in dentate nucleus,for which radiotherapy might be a risk factor.
文摘To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.
基金This project was supported by a grant from Guangdong Medical Research Foundation (No.Al999214).
文摘Objective： Conventional external beam irradiation techniques for nasopharyngeal carcinoma have limitations, and improving external beam irradiation techniques is needed to enhance the curative rate. This study was designed to cvaluate the difference in dose distribution of three dimensional conformal radiotherapy （3D CRT） and conventional treatment plan in early untreated nasopharyngeal carcinoma using a three dimensional treatment planning system. Methods： Twenty-two patients with early untreated nasopharyngeal carcinoma were selected. Conventional and 3D CRT plans were made for each of them and compared with respect to target volume coverage （V95）,normal tissue sparing （D50, D33 and D5, etc）, normal tissue complication probability （NTCP）. Results： The average volumetric dose comparison indicated that the V95 of PTVnx70 were 98.22% and 99.99% （P=0.06）, and PTVnd60, 98.41% and 99.63% （P=1.00）, PTV,x60, 98.44% and 99.98% （P=0.03）, PTVnx50, 98.85% and 99.63% （P=0.02） in conventional and 3DCRT treatment plans respectively. With respect to normal tissue sparing, the average D50 of unilateral parotid glands were 51.91 Gy and 64.30 Gy （P=0.00） respectively, and the unilateral temporomandibular joints, 49.98 Gy and 64.47 Gy （P=0.00）, the Dlcc of spinal cords, 44.98 Gy and 48.09 Gy （P=0.00） in 3D CRT and conventional plans. Conclusion： Though only a little bit better dose coverage of target volume in subclinical lesion region was reached in 3D CRT plans, it spared more normal tissues e.g. parotid glands and temporomandibular joints etc and decreased their NTCP while it got the similar dose distribution in target volumes as conventional plans did for these early nasopharyngeal carcinoma cases.
