1.Analysis of dose deviation by set-up error in the image guided intensity modulated radiotherapy for nasopharyngeal carcinoma
Jun LIU ; Hong CHEN ; Yonggang WANG ; Fei CHEN
Chinese Journal of Radiation Oncology 2011;20(2):160-163
Objective To discuss the set-up isocenter error based on kilovolt cone beam computed tomography (KVCBCT) and to investigate dose deviation led to set-up isocenter error. Methods 21 cases of nasopharyngeal carcinoma ( NPC ) treated with image guided intensity modulated radiotherapy (IG-IMRT)were investigated. The online KVCBCT scan, rigid image registration, set-up error was gained for 376 sets before radiotherapy. We sampled ten and fifteen setup isocenter error in the 376 sets randomly. Without changing beam angle,fields size and leaf sequences and dose weight et al. , we only replaced new isocenter and accumulated the new plan for ten or fifteen plans. We compared the percentage deviation between ten,fifteen times accumulated plans and normal ten , fifteen times plans. Results All 376 sets of KVCBCT image were analyzed for 21 cases. Under the condition of non-correction, the setup isocenter errors are 0. 75mm ± 1.13 mm, 0. 92 mm ±2. 15 mm,0. 82 mm ± 1.24 mm in left-right, superior-inferior and anteriorposterior directions respectively. So, we developed the margins which were 4 mm,6 mm、4 mm in three directions respectively from clinical tumor volume to planning tumor volume (PTV) calculated by two parameters model. In the fifteen accumulated plan, the deviation in the dose of 95% PTV (D95) was -7. 5% - - 11.9%, and the deviation in the D50 was -5. 1% - -8. 2%. Conclusions It is possible of small effects to normal organs and targets because of small error of patient displacement in one fraction.However, many small errors can led to considerable dose difference in targets and normal tissue in thirty fractions of all treatments period. So, according to two parameters model, PTV margin can be designed new planning and depended on IG-IMRT technique, which it will be significantly reduced these dose differences.
2.Clinical efficacy of daily online image-guided stereotactic body radiation therapy for lung cancer
Hong GAO ; Gaofeng LI ; Qiuzi ZHONG ; Yonggang XU ; Qinhong WU
Chinese Journal of Radiation Oncology 2014;23(4):322-325
Objective To analyze the clinical efficacy of daily online cone-beam computed tomography (CBCT)-guided stereotactic body radiation therapy (SBRT) for primary and metastatic lung cancer and its related factors.Methods From May 2009 to May 2013,36 patients with lung cancer were treated with SBRT,including 24 patients with primary lung cancer and 12 patients with metastatic lung cancer.The biologically effective dose at 10 Gy was ≥ 100 Gy in 85.7% of 42 lesions.Before each delivery,CBCT was acquired,and online automatic or manual registration was performed to make the tumors on CBCT within the planning target volume/primary gross tumor volume;the setup threshold was not set,and the couch was moved for correction.Results The 1-,2-,and 3-year sample sizes were 36,29,and 26,respectively.The 1-,2-,and 3-year local control (LC) rates were 96%,89%,and 72%,respectively.The 1-,2-,and 3-year cancer-specific survival (CCS) rates were 82%,74%,and 64%,respectively.The 1-,2-,and 3-year overall survival (OS) rates were 78%,64%,and 53%,respectively.Univariate analysis found no factors associated with LC.Multivariate analysis revealed no factors associated with OS.Both univariate and multivariate analyses showed that only tumor location (central type or peripheral type) was associated with CCS;the mean values (95% confidence intervals) of CCS in patients with central-type and peripheral-type lesions were 21.4 months (13.2-29.6 months) and 42.3 months (35.7-49.0months),respectively (P=0.024).Conclusions Daily online image-guided SBRT for primary or metastatic lung cancer can lead to a satisfactory LC.
3.A Study of Dose Evaluation for Clinac and Treatment Planning System Based on 2D Ionization Chambers Array
Jun LIU ; Hong CHEN ; Xiang PAN ; Li ZHANG ; Yonggang WANG
Chinese Journal of Medical Physics 2010;27(2):1699-1703
Objective: To discuss the methods and items for clinical linear accelerator (Clinac) and 3D treatment planning system (TPS)/intensity modulated radiotherapy(IMRT) system based on 2D ionization chambers array(2D-ICA). Methods: The 2D-I-CA laid on the anthropomorphic phantom with five centimeters and which was put on another five centimeters same phantom.All data have gained as following conditions: the SAD is 100 cm and the SSD is 90 cm; the fields' size are 2 cm, 5 cm, 10 cm,15 cm ,20 cm respectively and 2 cm×10 cm ,5 cm×20 cm ,20 cm×5 cm, MU=100 cGy;the Clinae and TPS were verified by some special items for checking their dose accuracy, such as, square fields, rectangular fields, and rectangular fields with 600 wedge or 300 wedge, which were measured for verification their flatness and symmetry. And some measured items were only for checking multileaf collimator (MLC) and TPS calculated accuracy. So, we developed moveable MLC fields and IMRT plans and compound fields to evaluate leafs side effects and leafs end effects and transmission effects. Results: The flatness value of square and rectangular fields was 100.07%~102.66%,and their symmetry value was 0.10%~1.49%; and these irradiate fields' size were compared with light fields' sizes, which the X direction deviation was-1.5%~0.7% ,the Y direction deviation was-1.4%~1.0%,and their average value was-0.47%.To verify calculated data for TPS ,we developed Gamma value and ab-solute value (<4%)to evaluate their accuracy. For square and rect-angular fields, The Gamma value was 92.02%~96.35%.In com-pound fields Which were composed with two half fields (X1 = 5 cm, X2 =0 cm, Y= 10 cm and X1 = 0 cm,X2 = 5 cm, Y=10 cm),the maximum deviation was about 5%.And five fields (2 cm×10 cm) composed one fields (10 cm×10 cm),the maximum deviation was about 10% in the joint place. The Gamma value of one fields was 96.6%, another was 93.2% in the moveable fields. Conclusions: To dollop 2D ionization chambers array to verify the dose for Clinac and TPS, it was so quick and simple, and it was important that it bring more accurate dose evaluation and more clinical quality assurance and quality control methods.
4.Correlational study of peritumoral brain edema,histological grades and the expression of Ki-67 in glio-mas
Yu HONG ; Yong ZHENG ; Yonggang WU ; Cheng ZHANG ; Jichao WANG
Journal of International Oncology 2015;(3):165-168
Objective To explore the correlation of peritumoral brain edema( PTBE)size,histologi-cal grades and the expression rate of Ki-67 in gliomas. Methods The data and specimens about 74 cases of gliomas in People's Hospital of Xinjiang Uygur Autonomous Region during 2010-2013 were collected. All cases were confirmed by surgery and pathology. According to preoperative MRI,PTBE was graded. Immunohisto-chemical discriminate the expression of Ki-67. HE coloration distinguish the histological grades. Results In this study,90. 54%(67/74)patients occured PTBE,the incidence of PTBE inⅠ,Ⅱ,Ⅲ,Ⅳlevel of groups were 100%(3/3),78. 95%(15/19),83. 33%(15/18),100%(34/34). Ki-67 expression was positive in 75. 68%(56/74)patients,and the rates were 0,36. 84%(7/19),94. 44%(17/18),94. 12%(32/34) in Ⅰ,Ⅱ,Ⅲ,Ⅳ level of groups. The expression rate of Ki-67 was 57. 14%(4/7),60. 00%(6/10),and 80. 70%(46/57)in normal group,Ⅰ-level groups of PTBE,Ⅱ-level groups of PTBE. The result of Kruskal-Wallis H showed that the PTBE from different grades was statistically significant(H=11. 304,P=0. 010). The expression rate of Ki-67 in different grade gliomas was statistically significant(H=38. 530,P﹤0. 05), The difference of expression Ki-67 in gliomas of different PTBE was statistically significant( H=6. 478,P=0. 039). The result of Spearman rank correlation analysis showed that the PTBE level increased with the histo-logical grade up in gliomas(r=0. 385,P=0. 001). The expression rate of Ki-67 increased with the histologi-cal grade up in gliomas(r=0. 692,P﹤0. 05),and the expression rate of Ki-67 increased with the degree of PTBE up in glomas( r =0. 256,P =0. 028 ). Conclusion Accorrding to the PTBE size,the histological grades and proliferation ability of glioma can be judged pre-operation. Ki-67 can be used as the indicator of pro-liferation activity of tumor,and also be used as the important basis of histological grades.
5.Preparation and characterization of mono PEGylated recombinant human interferon omega.
Hong LIU ; Yonggang CHENG ; Hongchun PAN ; Bo XU ; Li PENG ; Hongtao YANG ; Wei GUO
Acta Pharmaceutica Sinica 2012;47(3):393-8
The amino group PEGylation of rhIFNomega with monomethoxy polyethylene glycol succinimidyl succinate (mPEG-SS, 20 000) was investigated, and the modified mixture was separated and purified by ion exchange chromatography and gel filtration chromatography. Under the optimized purification conditions, the average content ofmono PEG-rhIFNomega in the collect liquid reached 182 microg x mL(-1). The average purified yield of mono PEG-rhIFNomega exceed to 22%, and the purity of mono PEG-rhIFNomega was greater than 98% by SDS-PAGE and RP-HPLC. Relative molecular mass of mono PEG-rhIFNomega was 43 790 detected by MALDI-TOF MS. The apparent molecular mass measured by SDS-PAGE was about 60 810. The purified PEG-rhIFNomega has the characteristics of typical PEGylated protein. Activity reservation rate of mono PEG-rhIFNomega was 15.0%, while the antigenicity decreased by at least 64 folds. In addition, the acid stability, thermal stability and stability in serum and trypsin solution of mono PEG-rhIFNomega were markedly better than those of the rhIFNomega. The pharmacological properties of mono PEG-rhIFNomega were significantly improved. The prepared PEG-rhIFNomega might be developed to a novel safe and long-acting interferon.
7.The survival analysis on localized prostate cancer treated with neoadjuvant endocrine therapy followed by intensity modulated radiation therapy
Hong GAO ; Gaofeng LI ; Qinhong WU ; Xuenan LI ; Qiuzi ZHONG ; Yonggang XU
Chinese Journal of Radiation Oncology 2010;19(2):127-130
Objective To restrospectively investigate clinical outcomes and prognositic factors in localized prostate cancer treated with neoadjuvant endocrine therapy followed by intensity modulated radiotherapy (IMRT). Methods Between March 2003 and October 2008, 54 localized prostate cancer treated by IMRT were recruited. All patients had received endocrine therapy before IMRT. The endocrine therapy included surgical castration or medical castration in combination with antiandrogens. The target of IMRT was the prostate and seminal vesicles with or without pelvis. The biochemical failure was defined according to the phoenix definition. By using the risk grouping standard proposed by D'Amico, patients were divided into three groups: low-risk group (n = 5), intermediate-risk group (n = 12), and high-risk group (n = 37). Kaplan-Meier method was used to calculate the overall survival rate. Prognostic factors were analyzed by univariate and multiple Cox regression analysis. Results The follow-up rate was 98%. The number of patients under follow-up was 39 at 3 years and 25 at 5 years. Potential prognostic factors, including risk groups, mode of endocrine therapy, time of endocrine therapy, phoenix grouping before IMRT, the prostate specific antigen doubling time (PSADT) before radiotherapy, PSA value before IMRT, interval of endocrine therapy and IMRT, irradiation region, and irradiation dose were analyzed by survival analysis. In univariate analysis, time of endocrine therapy (75 % vs 95 %, χ~2= 6. 45, P = 0. 011), phoenix grouping before IMRT (87% vs 96%, χ~2 = 4. 36, P = 0. 037), interval of endocrine therapy and IMRT (80% vs 95% ,χ~2= 11.60,P= 0. 001) ,irradiationdose(75% vs 91% ,χ~2=5.92,P= 0. 015) were statisticallysignificant prognostic factors for3 - year overall survival , and risk groups (85 vs 53 vs 29 , χ~2= 6. 40,P =0. 041) and PSADT before IMRT (62 vs 120, U =24. 50,P =0. 003) were significant factors for the median survival time. In the multiple Cox regression model, only time of endocrine therapy and phoenix grouping before IMRT were significantly related to the overall survival. The 3-year overall survival rates in patients with endocrine therapy less than 3 months versus more than 3 months were 75% versus 95% (χ~2= 5.45, P= 0.020). The 5-year overall survival rates in patients with biochemical failure versus nobiochemieal failure was 71% versus 92% (χ~2= 8.83 , P= 0.003) Conclusions Neoadjuvant endocrine therapy should last at least three months. Intensity modulate radiotherapy should start before biochemical failure after the endocrine therapy.
8.Impact of radiotherapy on myasthenia gravis in patients with malignant thymomas
Xiuyu HOU ; Yonggang XU ; Hong GAO ; Ming LI ; Gaofeng LI ; Mingyuan LIU
Chinese Journal of Radiation Oncology 1992;0(01):-
Objective To evaluate the change of myasthenia gravis(MG) during radiotherapy for patients with malignant thymomas.Methods Forty-five with malignant thymomas patients with were analyzed.The median total dose was DT54.2?Gy in 1.8-2.0?Gy /fraction,5 days a week.Anti-cholinesterase,such as pyridostigmine was used to control the MG symptoms.Results Forty-five patients completed radiotherapy on schedule except one from whom the treatment was was with drawn because of respiratory muscle involvement.Among these 44 patients,myasthenic symptom was relieved in 4 to various degrees,4 progressed,34 no change and 2 developed cholinergic crisis.Myasthenic symptom was not changed in one patient for whom radiotherapy had been standed before operation nor during the course of postoperative radiotherapy.Conclusions A course of radiotherapy of DT54.2?Gy,on fractionation of DT1.8-2.0?Gy modal would not aggravate myasthenia.However,proper use of anti-cholinesterase,careful observation and timely drug-adjustment are necessary.
9.The correlation between microvessel density, IDH1 mutation and the malignancy of glioma and its clinical significance
Yong ZHENG ; Yu HONG ; Yonggang WU ; Cheng ZHANG ; Jichao WANG ; Zhanglin QIAN
Cancer Research and Clinic 2015;27(1):24-26,31
Objective To study the correlation between microvessel density (MVD),isocitrate dehydrogenase 1 (IDH1) mutation and the malignancy of glioma,and its clinic significance.Methods The data and specimens of 40 patients with gliomas confirmed by surgery and pathology were collected.The relation between IDH1 mutation (detected by genetic sequence),MVD (detected by immunohistochemical coloration) and the malignancy of glioma was explored.5 cases of normal human brain tissues were used for comparative study.Results In normal brain tissue,Ⅰ,Ⅱ,Ⅲ,Ⅳ glioma,MVD counts were 8.12±1.64,25.10±1.27,27.00±1.98,42.80±10.75 and 56.50±5.23,respectively,and the overall difference was statistically significant (H =35.42,P < 0.05).The MVD counts in low-grade glioma (Ⅰ-Ⅱ) and high-grade glioma (Ⅲ-Ⅳ) were 23.94±8.03 and 45.54±8.19,respectively,and the difference was statistically significant (t =-8.369,P < 0.001).No mutation was found in normal human brain tissue,while in 20 cases of glioma specimens,there was IDH1 mutation with R132 as the mutation site and a MVD count of 31.11±13.47,and the other 20 cases of glioma specimens experienced no IDH1 mutation and the corresponding MVD count was 40.54±12.11.The difference of MVD counts of low-grade glioma and high-grade glioma was statistically significant (t =2.328,P=0.025).Conclusion MVD can be used as one of the histopathological grading metrics for glioma.IDH1 mutation occurs more frequently in grade Ⅱ and Ⅲ gliomas with R132 as the mutation site.
10.Efficacy of preoperative concurrent chemoradiotherapy in treatment of locally advanced middle-low rectal cancer
Ming LI ; Hong GAO ; Gaofeng LI ; Xia XIU ; Xiuyu HOU ; Yonggang XU ; Qiuzi ZHONG
Chinese Journal of Radiation Oncology 2014;23(4):286-290
Objective To evaluate the efficacy and tolerance of preoperative concurrent chemoradiotherapy in the treatment of locally advanced middle-low rectal cancer.Methods From June 2007 to June 2013,51 untreated patients with histopathologically proven rectal cancer (T3/T4 or N (+))were included in this study.Three-dimensional radiotherapy was delivered to the whole pelvic cavity at 45.0-50.4 Gy/25-28 fractions.Two cycles of chemotherapy with FOLFOX4 or XELOX were given concurrently at weeks 1 and 4 of radiotherapy.Surgery was performed at 4-8 weeks after chemoradiotherapy.Adjuvant chemotherapy with FOLFOX4 or XELOX was given within one month after surgery.The Kaplan-Meier method was used to calculate survival rates,and the log-rank test was used for univariate analysis;the Cox regression model was used for multivariate prognostic analysis.Results Fortynine patients completed the preoperative chemoradiotherapy and surgery.The median follow-up was 2.9 years.The overall sphincter preservation rate was 65%;the overall downstaging rate was 59%.Ten (20.4%) of all patients achieved a pathologic complete response (pCR).Grade ≥3 toxicities occurred in 25% of all patients,and the overall postoperative complication rate was 31%.The 3-and 5-year sample sizes were 24,12,respectively.The 3-and 5-year overall survival rates were 81% and 69%,respectively;the 3-and 5-year disease-free survival (DFS) rates were 76% and 60%,respectively;the 3-and 5-year local recurrence-free survival (LRFS) rates were 78% and 70%,respectively;the distant metastasis-free survival rates were 82% and 74%,respectively.The multivariate analysis showed that tumor downstaging was an independent prognostic factor for 5-year DFS and LRFS.Conclusions For locally advanced middle-low rectal cancer,preoperative radiotherapy with concurrent FOLFOX4/XELOX chemotherapy can increase pathologic downstaging rate,pCR rate,and sphincter preservation rate.Patients with tumor downstaging may have a better survival advantage.