1.Study of dosimetric variations introduced by anatomic changes during intensity-modulated radiotherapy
Daguang ZHANG ; Chengwen YANG ; Shengpeng JIANG ; Peiguo WANG ; Wei WANG
International Journal of Biomedical Engineering 2013;36(6):340-343
Objective To analyze the anatomic changes and dosimetric variations of patients with head-and-neck cancer during intensity-modulated radiotherapy and to assess the necessity of re-planning the treatment course.Methods Twenty-one nasopharyngeal carcinoma patients were selected to receive the second CT scan in the course of intensity-modulated radiotherapy,targets and organs at risk were re-contoured on the new CT images with the help of deformable registration software.Actual dose distribution delivered by the original treatment plan was calculated on the second CT image,and then the volume and doses of targets and organs at risk were compared between the planning CT and second CT.Results The volume of patient's head-and-neck outlines and GTVnd decreased significantly,the volume of cord and brainstem didn't change much,while the volume of left and right parotids decreased significantly by (24.23 ± 12.15)% and (25.82± 10.46)%,respectively.The parameters D95% and Dmean of PGTVnx kept stable,but the parameters D1cc of spinal cord PRV and brainstem PRV increased by (8.12± 10.32)% and (14.60±18.85)% respectively.The mean dose of the left and right parotids increased significantly by (27.43±17.67)% and (26.76±12.46)%,respectively.Conclusion The anatomical changes of patients undergoing intensity-modulated radiotherapy will cause significant dosimetric variations of the cord,brainstem and parotids,so it's meaningful and necessary to re-design the treatment plan in the course of radiotherapy.Repeat CT imaging and replanning during the course of IMRT is essential to ensure adequate doses to target volumes and safe doses to normal tissue.
2.Incidental nodal irradiation with involved-field conformal radiotherapy for patients with thoracic esophageal squamous cell carcinoma
Kai JI ; Lujun ZHAO ; Chengwen YANG ; Zhenxing FENG ; Ping WANG
Chinese Journal of Radiation Oncology 2013;(1):30-34
Objective To quantify the incidental irradiation dose (ⅡD) to lymph node stations of esophagus when treating patients with T1-4N0 M0 thoracic esophageal squamous cell carcinoma (ESCC) with a dose of 60 Gy/30f.Methods Twenty-nine patients with medically inoperable T1-4N0M0 thoracic ESCC were treated with three-dimensional radiotherapy on involved-field.The conformal CTV was re-created using a 3 cm margin in the proximal and distal direction (following the course of the esophagus) beyond the barium esophagogram,endoscopic examination and CT defined GTV and a 0.5 cm margin in the lateral and anteroposterior directions of the CT defined GTV.The PTV encompassed 1 cm proximal and distal margins,0.5 cm radiaI margin on the basis of CTV.Cervical,mediastinal and abdominal lymph nodes were delineated respectively.Equivalent uniform dose (EUD) and other dosimetric paraneters were calculated for each nodal station.Nodal region whose metastasis rate is greater than 5% was considered a high risk lymph node subgroups.Results Under a 60 Gy dose prescription,the median Dmean and EUD,V40 and V50 were ≥40 Gy,≥85% and ≥75% in most of the high risk nodal regions.For the subgroups whose EUD were less than 40 Gy,most of the ⅡD of these regions was significantly associated with the length and location of esophageal tumor (r =0.892,P =0.000).Conclusions Lymph node stations nearby of ESCC received considerable ⅡD with involved-field irradiation which could control subclinical lesions.But more clinical studies should be needed.
3.Impact of calculation resolution on Gamma pass rate for plan verification of intensity-modulated radiotherapy
Daguang ZHANG ; Shengpeng JIANG ; Chengwen YANG ; Wei WANG
International Journal of Biomedical Engineering 2014;37(2):103-106,114
Objective To analyze the impact of dose calculation resolution on Gamma pass rate for planar dose distribution verification of intensity-modulated radiotherapy (IMRT),and to find out the appropriate calculation resolution value with specific applied criteria.Methods 25 IMRT plans were selected for the planar dose verification.The Gamma pass rates with 3 mm/3%,2 mm/2% and 1 mm/1% criteria were compared and analyzed.The planar dose distributions were calculatedand exported from TPS with different resolutions of 0.5,1,2,3,4 and 5 mm.The pass rates of Gamma analysis between the computed dose distributions with different resolutions and the dose distributions measured by Mapcheck device were compared and analyzed.Results The average Gamma pass rates of all the 225 fields decreased with the increment of calculation resolution.When the pass rates of Gamma analysis were calculated using 3 mm/3% criteria,the gamma pass rate with 1 mm and 0.5 mm calculation resolution were (98.3±1.3)% and (98.3±1.2)%,respectively.The results were almost the same and the difference wasn't statistically significant (P>0.05).The gamma pass rates with greater than or equal to3 mm calculation resolution were significantly less than the pass rate with 0.5 mm calculation resolution (P<0.05).When the pass rates of Gamma analysis were calculated using 2 mm/2% criteria,all the pass rates with greater than 0.5 mm calculation resolution were significantly less than the pass rate with 0.5 mm calculation resolution (P<0.05).Conclusions The Gamma pass rates of planar dose verification reduce significantly with the increment of calculation resolution.In order to reduce the effect of calculation resolution on Gamma pass rate,the lower calculation resolution should be used.When using the 3 mm/3% criteria for the Gamma analysis,1 mm calculation resolution is recommended.When using the 2 mn/2% criteria for the Gamma analysis,0.5 mm calculation resolution is recommended.The appropriate calculation resolution will ensure the reliability of planar dose verification.
4.Characteristics of Fungus Colony in Oral Cavity of HIV-infected Patients with Highly Active Antiretroviral Therapy (HAART)
Jia YANG ; Xiaokang ZHANG ; Chongxi LI ; Chengwen LI
Journal of Kunming Medical University 2016;37(7):117-120
Objective To identify the characteristics oral fungus in HIV-infected patients with HAART in Kunming.Methods Oral mucosal swab samples were collected from 99 patients with HIV infection with or without HAART.The fungi were isolated and cultured,and were identified by using API 20 C AUX yeast identification system.Results The positive rate of oral Candida in was significantly higher in HIV-infected patients without HAART (53.3%) than those with HAART (20.4%) (x2=11.669,P<0.01).In 41 strains of isolated candida,C.albicans was the most prevalent (78.0%),followed by C parapsilosis (9.8%),C.glabrata (9.8%) and C tropicalis (2.4%).Conclusions HAART can decrease the positive rate of oral Candida in patients with HIV infection,but has little effect on asymptomatic HIV carrier.
5.Effect of acupuncturing Back-Shu points on gastrin, motilin of chronic atrophic gastritis model in rats
Gaiqin YANG ; Bingqi ZHANG ; Chengwen JIA ; Jia ZUO ; Songsong JIA
International Journal of Traditional Chinese Medicine 2014;(9):819-820,823
Objective To study the effect of gastrin, motilin of chronic atrophic gastritis model in rats by acupuncturing at back-shu points. Methods 60 SD rats were randomly divided into blank control group, model control group, omeprazole group, back-shu points group, with 15 rats in each group, and to establish the model of chronic atrophic gastritis by irregular diet that given rats odd and even days. The blank control group, model control group were fed with normal saline, 2ml/time, 1 time/day. The omeprazole group was given oral gavage(Omeprazole 0.44 mg/kg, Clarithromycin 6.92 mg/kg, Metronidazole 7.6 mg/kg), 1 time/day. Back-shu points group received acupuncture at “Geshu”“Ganshu”“Pishu”“Weishu”“Shenshu”, retaining 15 min, 1 time/day. After 30 days, the content of ELSIA was used to detect the serum gastrin, motilin. Results ①GAS of model control group(54.25±5.70)pg/ml was significantly decreased compared with blank control group(66.63± 5.99)pg/ml, the difference was statistically significant (P<0.05). Compared with the model control group, GAS content of omeprazole group(62.70±8.55)pg/ml and back-shu Points group(66.27±3.79)pg/ml were higher, showed significant differences(P<0.05). ②MOT of model control group(223.60±17.83)pg/ml was significantly increased compared with the blank control group(188.45 ± 8.90)pg/ml, the difference was statistically significant(P<0.05). MOT of omeprazole group(200.16 ± 4.38)pg/ml and back-shu Points group(190.11±10.04)pg/ml were lower than those in the model control group, there was statistically significant difference(P<0.05). Conclusion Acupuncturing at back-shu acupoints can increase the content of GAS, reduce content of MOT, regulate gastrointestinal hormone in rats of chronic atrophic gastritis model.
6.The clinical analysis of mercury poisoning in 92 cases
Xiaoling LIU ; Hanbin WANG ; Chengwen SUN ; Xishan XIONG ; Zhi CHEN ; Zhaosheng LI ; Bo HAN ; Gang YANG
Chinese Journal of Internal Medicine 2011;50(8):687-689
Objective To summarize the clinical features of mercury poisoning diagnosed by blood and urine tests for improving the diagnosis and treatment of the disease.Methods Poisoning causes,clinical manifestations,diagnosis,treatment and prognosis were retrospectively reviewed in 92 in-patients with mercury poisoning in our hospital from January 2000 to April 2010.Results Of the 92 patients,37 were male and 55 were female with an average age of 33.1(2-65)years old.The mercury poisoning was caused by occupational exposure and non-occupational exposure,such as iatrogenic exposure,life exposure and wrong intake or suicidal intake of mercury-containing substances,mainly through respiratory tract,digestive tract and skin absorption.The most common clinical symptoms were as the followings:nervous system symptom,such as memory loss in 50 eases(54.3%),fatigue in 34(37.0%),numb limb in 25 (27.2%),dizziness and headache in 22(23.9%),cacesthesia in 20(21.7%),fine tremor(finger tip,tongue tip,eyelids)in 15(16.3%),insomnia and more dreams in 12(13.0%);gastrointestinal symptoms:nausea in 16 (17.4%),abdominal pain in 14(15.2%),stomatitis in 5(5.4%);joint and muscle symptoms:muscle pain in 16(17.4%),joint pain in 5(5.4%);cardiovaseular system:chest tightness,hean palpitations in 6(6.5%);urinary system:edema in 9(9.8%);other system:hidrosis in 20(21.7%).After the treatment with sodium dimercaptopropane sulfonate (DMPS),the symptoms were gradually alleviated.Their gastrointestinal,cardiovascular symptoms were alleviated within 2 weeks;neurological symptoms were alleviated within 3 months;kidney damage showed a slower recovery and could be completely'alleviated within 6 months.Conclusions Because of its diverse clinical symptoms,the mercury poisoning was easy to misdiagnosis and missed diagnosis:therefore the awareness of the disease should be further enhanced.Leaving from the poisoning environment timely and giving appropriate treatment with DMPS will lead to a satisfactory prognosis.
7.Gross tumor volume delineation with combination of non-contrast/contrast CT and FDG PET in pancreatic cancer
Linlin GONG ; Ningbo LIU ; Lei ZHU ; Chengwen YANG ; Lujun ZHAO ; Ruijian LI ; Ping WANG
Chinese Journal of Radiation Oncology 2012;21(3):255-257
ObjectiveTo investigate the application of non-contrast and contrast-enhanced 18FDG PET/CT in the delineation of gross tumor volume ( GTV ) of pancreatic cancer.MethodsBetween Jan.2008 and Dec.2009,twenty-one patients with unresectable locally advanced pancreatic cancer or recurrent pancreatic cancer after surgery in our hospital had both non-contrast CT and PET images acquired at the same body position.Among the whole group,eleven patients also had contrast CT images.The image data sets were transferred to the treatment planning workstation for registration.Then gross tumor volumes ( GTV )were delineated independently using the information of PET images,contrast/non-contrast CT scan and contrast/non-contrast PET-CT fusion images.The differences of mean volume in these different sets of GTV were analyzed.Results For the whole group,the mean volume of non-contrast GTVCT,GTVPET,noncontrast GTVPET-CT were 76.9 cm3,47.0 cm3 and 44.5 cm3,respectively.The mean volume of non-contrast GTVPET-CT was significantly smaller than non-contrast GTVCT ( z =-3.91,P =0.000 ).For the eleven patients with contrast CT,the mean volume of contrast GTVCT,GTVPET,contrast GTVPET-CT were 64.1 cm3,45.1 cm3 and 49.3 cm3,respectively.The mean volume of contrast GTVPET-CT was significantly smaller than contrast GTVCT (z =-2.13,P =0.033 ).No significant differences were found between contrast PET-CT and non-contrast PET-CT (z =-0.80,P =0.424).ConclusionsCo-registration of PET and contrast/noncontrast CT information in pancreatic cancer may improve the accuracy of GTV delineation,and possibly reduce the adverse effect of irradiation.
8.Feasibility of Gas as A Contrast Agent for Stomach MRI Examination
Chengwen WANG ; Xiaomei ZHANG ; Xiaoping YANG ; Yuxian WANG ; Pingde QI ; Lili HUANG ; Zhenmao WANG
Chinese Journal of Medical Imaging 2015;(10):739-741,750
PurposeGas is rarely studied or reported to be used as a contrast agent of stomach MRI examination because it might lead to susceptibility artifacts, the purpose of this study is to evaluate the application value of gas as a contrast agent of stomach MRI examination.Materials and Methods Sixty patients who were supposed to have upper abdominal MRI examination were enrolled, all patients were given intramuscular injection of 654-2, gas from oral ingestion of aerogenic powder was used as contrast agent, MRI examinations were then executed and images quality of MRI were analyzed and classified. Results All 60 patients felt it acceptable for the taste of aerogenic powder, only 5 cases felt uncomfortable during swallowing; no adverse reactions were observed in all the 60 cases. Excellent gas contrast medium filling of the stomach cavity were confirmed with CT scanning in 57 cases (95%). Gas acted as a negative contrast agent in the stomach cavity with good continuity and uniform signal; and the proximal part of the stomach and duodenum was well displayed. There were 21 cases (35.0%) classified as grade 0 about their image quality; 25 cases (41.7%) as grade 1; 6 cases (10.0%) as grade 2; 8 cases (13.3%) as grade 3, with total 52 cases (86.7%) with image quality which could meet the requirement of clinical diagnosis. Cases of grade 0-2 showed coronary T2WI images with vivid stomach contour and clear stomach wall with no artifacts; axial FS-T2WI images with few artifacts, relative clear stomach contour and good display of stomach wall; less artifact could be found in axial TIWI image with good display of stomach wall; axial T2WI images showed more artifacts and gastric wall was displayed not clear enough. Cases classified as grade 3 showed coronal T2WI, FS-T2WI, T1WI and T2WI axial images with significant artifacts, vague outline, distortions or ghosting of the contour of stomach and tumor.Conclusion As contrast agent for gastric MRI examination, gas is safe, homogeneously distributed with stable signal characteristic and is easy for patients to tolerate.
9.A Survey of Oral Health Knowledge and Behavior among HIV-infected Patients
Rong LI ; Yan WEN ; Liuying GE ; Kaiwen DUAN ; Xianghong YANG ; Chengwen LI
Journal of Kunming Medical University 2013;(10):142-144,164
Objective To assess oral health knowledge and behaviors of self-care among HIV infected patients in Yunnan, China. Methods Questionnaire survey was performed to collect the information about behaviors of oral self-care and seeking medical advice and diets of 216 HIV-infected patients who came from the Third Hospital of Kunming. The data were then statistically analyzed. Results Half of the patients were diagnosed over six months. The smoking of the HIV-positive were serious and the gingival bleeding was less, but there was obvious discomfort in oral cavity when eating. In addition,the standard method of cleaning teeth was below 20%, less of 50%patients could clean the oral cavity in time after diet and they didn't replace their toothbrushes timely. Over half of patients asked artificial tooth and exodontias on treatment. Conclusion It is necessary to pay more attention to the oral health knowledge and self-care behaviors of HIV-infected patients so as to improve the quality of life.
10.The incidence of oral candidiasis in patients with human immunodeficiency virus infection/acquired immunodeficiency syndrome from Yunnan, China.
Yan WEN ; Chengwen LI ; Junhaoxiang PEI ; Jinsong BAI ; Xianghong YANG ; Kaiwen DUAN
Chinese Journal of Stomatology 2014;49(8):454-458
OBJECTIVETo assess the incidence of oral candidiasis and its influencing factors in patients with human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS).
METHODSAn oral examination was conducted in the 1 566 HIV/AIDS patients in the Third Hospital of Kunming from March 2008 to September 2012 (M/F: 1 062/504, age range: 0.2 to 84.0 years old). The HIV viral load (HIV- RNA) and peripheral blood CD4 count were respectively analyzed by Bayer Q340 fluorescence signal surveying instrument (bDNA method) and flow cytometry analysis. The information on usage of highly active anti-retroviral (HAART) drugs and transmission of HIV were obtained through questionnaires. The incidence of oral candidiasis in patients with different HIV-RNA levels and CD4 count and the use of HAART was analyzed and compared.
RESULTSThe total incidence of oral candidosis was 31.0% (486/1 566) and there was no difference in sex. The oral lesions were presented by three types, psudomembranous candidosis (PC), erythematous candidosis (EC) and angular cheilitis (AC), and the morbidity was 13.9% (217/1 566), 17.0% (267/1 566) and 4.9% (77/1 566), respectively. The average level of CD4 count in psudomembranous candidosis, erythematous candidosis and angular cheilitis [81.0 (146.0), 74.0 (152.0) and 69.0 (121.5) cell/µl] showed no significant difference (P > 0.05). The incidence of oral candidiasis in non-HAART and HAART subjects were 36.3% (402/1 107) and 18.3% (84/459), respectively (P = 0.000). The CD4 count and absolute counts of HIV viral load in oral candidiasis patients and non-oral candidiasis patients had significant difference (Z = -10.261, P = 0.000 and Z = -4.762, P = 0.000).
CONCLUSIONSThe morbidity of oral candidiasis in HIV/AIDS patients in Yunnan Province was high, including PC, EC and AC and hyperplastic candidosis was not detected. The incidence was related to the degree of immune suppression and HIV viral load.
AIDS-Related Opportunistic Infections ; epidemiology ; Acquired Immunodeficiency Syndrome ; complications ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; CD4 Lymphocyte Count ; Candidiasis, Oral ; complications ; epidemiology ; Cheilitis ; Child ; Child, Preschool ; China ; epidemiology ; HIV Infections ; Humans ; Incidence ; Infant ; Middle Aged ; Mouth Diseases