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1.
Br J Radiol ; 87(1042): 20140428, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25135439

RESUMO

OBJECTIVE: To compare internal target volume (ITV) generated using population-based displacements (ITV_study) with empty and full bladder scan fusion (ITV_EBFB) for organ-at-risk (OAR) doses during adjuvant intensity-modulated radiation therapy (IMRT) for cervical cancer. METHODS: From January 2011 to October 2012, patients undergoing IMRT were included. CT simulation was carried out after inserting vault markers. Planning target volume (PTV)_EBFB received 50 Gy per 25 fractions. Pre-treatment megavoltage CT (MVCT) was performed. MVCTs were registered using bony landmarks with Day 1 MVCT. Displacement of the centre of mass of markers was measured along each axis. Directional ITV was calculated using mean ± 2 standard deviations (SDs) (ITV_study). Replanning was performed using PTV study, and OAR doses were compared with PTV_EBFB using Wilcoxon test. RESULTS: A total of 348/386 data sets were evaluable for 16 patients. The median vaginal displacement was 1.2 mm (SD, 1.3 mm), 4.0 mm (SD, 3.5 mm) and 2.8 mm (SD, 3.3 mm) in the mediolateral, superoinferior and anteroposterior directions, respectively. The ITV margins were 4.1, 10.3 and 10.6 mm. ITV_study and ITV_EBFB were 115.2 cm(3) (87.7-152.2 cm(3)) and 151 cm(3) (95.7-277.1 cm(3)) (p < 0.0001), respectively. PTV_study and PTV_EBFB were 814 and 881 cm(3) (p < 0.0001), respectively. Median doses to the bladder were lower with the PTV_study (46.2 Gy vs 43.2 Gy; p = 0.0001), and a similar trend was observed in the volume of the small bowel receiving 40 Gy (68.2 vs 60.1 cm(3); p = 0.09). CONCLUSION: Population-based PTV margins can lead to reduction in OAR doses. ADVANCES IN KNOWLEDGE: Population-based ITV may reduce OAR doses while executing adjuvant IMRT for cervical cancer.


Assuntos
Radioterapia de Intensidade Modulada/métodos , Neoplasias do Colo do Útero/radioterapia , Vagina/efeitos da radiação , Fracionamento da Dose de Radiação , Feminino , Humanos , Histerectomia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Radiografia Intervencionista , Radioterapia Adjuvante , Radioterapia de Alta Energia , Bexiga Urinária/diagnóstico por imagem , Neoplasias do Colo do Útero/cirurgia
2.
Br J Radiol ; 87(1033): 20130583, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24288401

RESUMO

OBJECTIVE: To evaluate three-dimensional (3D) displacements of gastric remnant during adjuvant radiation. METHODS: From January 2011 to September 2012, patients undergoing adjuvant image-guided intensity-modulated radiation on tomotherapy were included. Megavoltage CT (MVCT) data sets from daily treatment were coregistered with Day 1 MVCT. Residual stomach remnant was delineated on the data set, while the remaining were blinded to previous day contours. Gastric volume and centre of mass (COM) were determined for all data sets. The 3D deviation of COM was calculated for each fraction. Mean 3D and standard deviation (SD) were calculated for each patient and study population, and a 95% confidence interval (CI) was determined. Also, systematic and random errors for patient population and internal target volume (ITV) margin were calculated using the van Herk formula. RESULTS: There were 119 images available for 15 patients. Mean volume of remnant was 319 cm(3) (146-454 cm(3)). Gastric remnant expanded in different directions with no specific directional expansion. Average deviations in mediolateral, superoinferior and anteroposterior directions were 9 mm (3-25 mm; SD, 5 mm), 6 mm (3-16 mm; SD, 4 mm) and 5 mm (1-10 mm; SD, 3 mm), respectively, with 95% CI of 18, 15 and 11 mm, and ITV margins of 19.2, 13.5 and 7.8 mm, respectively. CONCLUSION: There is large variation in gastric remnant volume during the course of radiation. Large displacements observed in the present study necessitate the need to investigate adaptive techniques for optimizing intensity-modulated radiotherapy (IMRT) delivery. ADVANCES IN KNOWLEDGE: An adaptive strategy needs to be developed to optimize IMRT delivery for adjuvant gastric irradiation.


Assuntos
Coto Gástrico/patologia , Imageamento Tridimensional/métodos , Radioterapia Adjuvante/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/radioterapia , Carga Tumoral/efeitos da radiação , Adenocarcinoma/patologia , Adenocarcinoma/radioterapia , Carcinoma de Células em Anel de Sinete/patologia , Carcinoma de Células em Anel de Sinete/radioterapia , Feminino , Humanos , Masculino , Estadiamento de Neoplasias , Neurofibroma Plexiforme , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos
3.
Cogn Neuropsychiatry ; 16(5): 403-21, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21390926

RESUMO

Introduction. Hearing voices occurs in people without psychosis. Why hearing voices is such a key pathological feature of psychosis whilst remaining a manageable experience in nonpsychotic people is yet to be understood. We hypothesised that religious voice hearers would interpret voices in accordance with their beliefs and therefore experience less distress. Methods. Three voice hearing groups, which comprised: 20 mentally healthy Christians, 15 Christian patients with psychosis, and 14 nonreligious patients with psychosis. All completed (1) questionnaires with rating scales measuring the perceptual and emotional aspects of hallucinated voices, and (2) a semistructured interview to explore whether religious belief is used to make sense of the voice hearing experience. Results. The three groups had perceptually similar experiences when hearing the voices. Mentally healthy Christians appeared to assimilate the experience with their religious beliefs (schematic processing) resulting in positive interpretations. Christian patients tended not to assimilate the experience with their religious beliefs, frequently reporting nonreligious interpretations that were predominantly negative. Nearly all participants experienced voices as powerful, but mentally healthy Christians reported the power of voices positively. Conclusion. Religious belief appeared to have a profound, beneficial influence on the mentally healthy Christians' interpretation of hearing voices, but had little or no influence in the case of Christian patients.


Assuntos
Alucinações/psicologia , Transtornos Psicóticos/psicologia , Religião , Adulto , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Inquéritos e Questionários
4.
Br J Sports Med ; 40(12): 981-3, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17008344

RESUMO

BACKGROUND: The second to fourth finger length ratio (2d:4d) is thought to be related to diverse traits including cognitive ability, disease susceptibility, and sexuality. OBJECTIVE: To examine the relationship between 2d:4d and sports ability in women. METHODS: Hand radiographs from 607 women (mean age 54 years) were used to estimate 2d:4d. Ranking of sports ability was on a scale (1-5). RESULTS: The highest achieved level of participation in any sport was significantly negatively associated with 2d:4d (b = -4.93, p = 0.01) as was the relationship between 2d:4d and running level (b = -6.81, p = 0.034). Ability in other sports also showed a negative relationship albeit non-significant. CONCLUSIONS: These results suggest that a low 2d:4d ratio is related to increased female sports ability. It can be postulated that this ratio may predict potential sports ability. Understanding the mechanisms underpinning this relationship may give important insights into musculoskeletal fitness, health and disease.


Assuntos
Antropometria , Aptidão/fisiologia , Dedos/anatomia & histologia , Esportes/fisiologia , Adulto , Idoso , Feminino , Dedos/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Radiografia
6.
Phys Rev E Stat Nonlin Soft Matter Phys ; 65(1 Pt 2): 016404, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11800787

RESUMO

The linear and nonlinear propagation of dust-acoustic waves in a dusty plasma bounded in finite geometry has been theoretically investigated. It is found that the finite geometry of the bounded plasma makes a significant contribution to the instability of the wave. Moreover, the pseudopotential has a positive and inverted profile that prevents the trapping of particles and does not favor solitary waves in bounded dusty plasma.

7.
Trends Ecol Evol ; 9(10): 361-3, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21236890
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