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1.
International Journal of Radiation Research. 2017; 15 (1): 49-61
en Inglés | IMEMR | ID: emr-187496

RESUMEN

Background: A method to track liver tumor motion signals from fluoroscopic images without any implanted gold fiducial markers was proposed in this study to overcome the adverse effects on precise tumor irradiation caused by respiratory movement


Materials and Methods: The method was based on the following idea: [i] Before treatment, a series of fluoroscopic images corresponding to different breathing phases and tumor positions were acquired after patient set-up; [iii] The wavelet transform method and Canny edge detection algorithm were used to detect motion trajectory of the diaphragm; [iv] The motion curves of center of lipiodol in the images were obtained by mathematical morphology and median filtering algorithm. The method was evaluated using by five sequences of fluoroscopic images from TACE patients who received transcatheter arterial chemoembolization therapy


Results: The position of liver tumor was significantly affected by respiratory motion; the motion trajectories of the diaphragm and lipiodolagreed well with the manually marked locations in amplitude and period; the motion trajectories of the diaphragm and lipiodol almost had similar period and amplitude in one treatment fraction. The respiratory period and amplitude of the same patient in different fractions had no significant differences; however, the difference was obvious for different patients. The proposed lipiodol detection methods can effectively reflect the relevant rules of tumor location caused by respiratory movement


Conclusion: Direct tracking of liver tumor motion in fluoroscopic images is feasible. The automatic detection method can reflect the characteristics of respiratory and tumor motions, which can save much time and significantly improve measurement precision compared with manual measurement


Asunto(s)
Humanos , Masculino , Persona de Mediana Edad , Quimioembolización Terapéutica , Marcadores Fiduciales , Radioterapia Guiada por Imagen , Fluoroscopía , Reconocimiento de Normas Patrones Automatizadas/métodos
2.
International Journal of Radiation Research. 2016; 14 (1): 1-7
en Inglés | IMEMR | ID: emr-183188

RESUMEN

The radiobiological effects of high atomic number and energy [HZE particles] ion beams are of interest for radioprotection in space and tumor radiotherapy. Space radiation mainly consists of heavy charged particles from protons to iron ions, which is distinct from common terrestrial forms of radiation. HZE particles pose a significant cancer risk to astronauts on prolonged space missions. With high delivered energies and intense ionization, HZE particles can damage not only the biological systems but also the shielding materials. HZE particles are more effective than low-LET radiation like gamma- or X-rays to induce genetic mutation and cancer. On Earth, similar ions are being used for targeted cancer therapy due to the advantage of the inverse dose profile, with delivering higher doses to the tumor while keeping lower doses to the surrounding tissues. In this review, we focus on the recent insights into the biological effects caused by HZE particles and the corresponding mechanism. We also discuss the current application of HZE particle in cancer therapy. Understanding the mechanisms underlying the repair of DNA damage induced by HZE particles contribute to accurately estimate the risks to human health associated with HZE particle exposure and to improve the effectiveness of tumor radiotherapy

3.
International Journal of Radiation Research. 2014; 12 (3): 203-209
en Inglés | IMEMR | ID: emr-149942

RESUMEN

Ovarian immature teratoma is a very rare type of tumor associated with a high relapse rate and mortality. Correspondingly, early diagnosis is important for effective treatment. The goal of this study was to retrospectively analyze the ultrasound characteristics of 11 cases of immature teratomas. Between January 2002 and December 2010, 11 patients were diagnosed with pathologically confirmed immature teratomas. Patients enrolled in this study underwent a transabdominal ultrasound examination prior to surgery. Tumor size, shape, internal echo, calcification, cystic degeneration, and blood flow for each immature teratoma were analyzed. Levels of alpha fetal protein [alphaFP] were also evaluated. The average tumor size was 8 cm [range, 4-13]. Echo patterns obtained included mixed echo [n = 7], solid echo [n = 2], and cystic echo [n = 2]. Coarse calcifications were detected in five cases, while blood flow signal was detected in one case, and ascites were detected in three cases. Only one case had elevated levels of alphaFP. Ultrasound imaging of immature teratomas detected large tumors that were predominantly involved mixed-echo masses, cystic degeneration, and coarse calcification on the cavity wall. In some cases, blood flow signal was detected in the mass and ascites were present in the abdominal cavity


Asunto(s)
Humanos , Femenino , alfa-Fetoproteínas , Ultrasonografía , Estudios Retrospectivos , Calcinosis
4.
Biomedical and Environmental Sciences ; (12): 180-187, 2010.
Artículo en Inglés | WPRIM | ID: wpr-360605

RESUMEN

<p><b>OBJECTIVES</b>To determine whether a large-scale physical activity intervention could affect body composition in primary school students in Beijing, China.</p><p><b>METHODS</b>The study design was one-year cluster randomized controlled trial of physical activity intervention (20 min of daily exercise in the classroom) with an additional year of follow-up among 4 700 students aged 8-11 years at baseline.</p><p><b>RESULTS</b>After the one-year intervention, BMI increased by 0.56 kg/m(2) (SD 1.15) in the intervention group and by 0.72 kg/m(2) (SD 1.20) in the control group, with a mean difference of -0.15 kg/m(2) (95% CI: -0.28 to -0.02). BMI z score decreased by -0.05 (SD 0.44) in the intervention group, but increased by 0.01 (SD 0.46) in the control group, with a mean difference of -0.07 (-0.13 to -0.01). After another year of follow up, compared to the control group, children in the intervention group had significantly lower BMI (-0.13, -0.25 to -0.01), BMI z score (-0.05, -0.10 to -0.01), fat mass (-0.27 kg, -0.53 to -0.02) and percent body fat (-0.53, -1.00 to -0.05). The intervention had a more pronounced effect on weight, height, BMI, BMI z score, and body composition among obese children than among normal weight or overweight children. Compared to the control group, the intervention group had a significantly higher percentage of children who maintained or reduced their BMI z score at year 1 (P=0.008) and year 2 (P=0.04).</p><p><b>CONCLUSIONS</b>These findings suggest that 20 min of daily moderate to vigorous physical activity during the school year is a feasible and effective way to prevent excessive gain of body weight, BMI, and body fatness in primary school students.</p>


Asunto(s)
Niño , Femenino , Humanos , Masculino , Composición Corporal , China , Epidemiología , Ejercicio Físico , Obesidad , Epidemiología
5.
Iranian Journal of Nutrition Sciences and Food Technology. 2007; 2 (3): 1-12
en Persa | IMEMR | ID: emr-83051

RESUMEN

Postmenopausal women with the metabolic syndrome are at a high risk of oxidative stress. Several studies have suggested possible antioxidant properties of soy, but little evidence is available regarding the effect of soy on oxidative stress in postmenopausal women with the metabolic syndrome. The aim of this study was to determine the effects of consumption of soy and soy protein on the plasma total antioxidant capacity [TAC] and malondialdehyde [MDA] levels in postmenopausal women with the metabolic syndrome. This randomized cross-over trial was conducted on 42 postmenopausal women with the metabolic syndrome as defined by ATP III. Participants were randomly assigned to consume a control diet, a soy-protein diet, or a roasted soy diet. Dietary Approaches to Stop Hypertension [DASH] was used in all three intervention periods. Red meat [1 serving/day] was substituted by soy protein or roasted soy in the respective diets. Each intervention period was 8 weeks and each wash-out period 4 weeks. Means of the variables were calculated by the repeated measures analysis of variance. There were significant differences among the control, soy-protein and roasted soy diets as regards the final MDA values [0.70, 0.64, and 0.63, micro mol/L, respectively; global P<0.01]. The final TAC values were also different among the 3 groups in the same order [1.95, 2.03, and 2.11 micro mol/ml, respectively; P<0.01]. As compared to the control values, the final TAC values for TAC increased by +4.5% on the roasted soy diet [p<0.01] and by +5.8% on the soy-protein regimen [p<0.01], while MDA levels decreased [7.9% in the roasted soy group; p<0.01, and 9.4% in the soy protein group; p<0.01]. Soy consumption reduced plasma MDA and increased plasma TAC levels in postmenopausal women with the metabolic syndrome


Asunto(s)
Humanos , Femenino , Estrés Oxidativo , Enfermedades Metabólicas , Posmenopausia , Malondialdehído
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