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1.
World J Surg ; 45(10): 3191-3197, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34304274

RESUMO

BACKGROUND: The study aims to assess the safety and feasibility of the robotic dual-console during a robotic distal pancreatectomy METHODS: The data of the consecutive patients submitted to RDP from 2012 to 2019 at the Verona University were retrieved from a prospectively maintained database. The patients submitted to RDP were divided into the dual-console platform group (DG) and compared to the standard robotic procedure group (SG). RESULTS: In the study period, 102 robotic distal pancreatectomies were performed, of whom 42 patients (41%) belonged to the DG and 60 patients (59%) to the SG. Higher operation time was recorded in the DG compared to the SG (410 vs. 265 min, p < 0.001). The overall conversion rate of the series was 7% (n 7 patients). All the conversions were observed in the SG (p = 0.021). No differences in morbidity or pancreatic fistula rate were recorded (p > 0.05). No mortality events in the 90th postoperative days were reported in this series. CONCLUSIONS: The robotic dual-console approach for distal pancreatectomy is safe, feasible, and reproducible. The postoperative surgical outcomes are comparable to the standard RDP with the single-console da Vinci Surgical System®. This surgical technique can widely and safely improve the robotic surgical training program.


Assuntos
Laparoscopia , Neoplasias Pancreáticas , Procedimentos Cirúrgicos Robóticos , Robótica , Humanos , Duração da Cirurgia , Pancreatectomia , Fístula Pancreática/epidemiologia , Fístula Pancreática/etiologia , Neoplasias Pancreáticas/cirurgia , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/efeitos adversos
2.
Endocrine ; 74(1): 180-187, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34036514

RESUMO

PURPOSE: Data regarding the clinical management and follow-up of pancreatic neuroendocrine tumors (PanNETs) associated with Von Hippel-Lindau (VHL) syndrome are limited. This study aimed to assess clinical presentation, genotype-phenotype correlations, treatment and prognosis of PanNETs in a series of VHL syndrome patients. METHODS: Retrospective analysis of data of patients observed between 2005 and 2020. RESULTS: Seventeen patients, including 12 probands and 5 relatives (mean age 30.8 ± 18.4; 7 males), were recruited. PanNETs were found in 13/17 patients (77.5%) at a median age of 37 years: 4/13 (30.7%) at the time of VHL diagnosis and 9 (69.3%) during follow up. Six (46.1%) PanNET patients underwent surgery, whereas seven were conservatively treated (mean tumor diameter: 40 ± 10.9 vs. 15 ± 5.3 mm respectively). Four patients (30.7%) had lymph node metastases and a mean tumor diameter significantly larger than the nonmetastatic PanNETs (44.2 ± 9.3 vs. 17.4 ± 7 mm, p = 0.00049, respectively). Five (83.3%) operated patients had stable disease after a median follow up of 3 years whereas one patient showed liver metastases. Six (85.7%) non-resected PanNETs were stable after a median follow-up of 2 years, whereas one patient developed a new small PanNET and a slight increase in diameter of a pre-existing PanNET. No correlation was found between the type of germline mutation and malignant behavior of PanNETs. CONCLUSIONS: PanNETs are a common disease of the VHL syndrome and can be the presenting feature. Tumor size rather than genetic mutation is a prognostic factor of malignancy.


Assuntos
Tumores Neuroendócrinos , Neoplasias Pancreáticas , Doença de von Hippel-Lindau , Adolescente , Adulto , Criança , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/genética , Neoplasias Pancreáticas/genética , Estudos Retrospectivos , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Adulto Jovem , Doença de von Hippel-Lindau/complicações , Doença de von Hippel-Lindau/genética
3.
Br J Surg ; 108(7): 811-816, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-33724300

RESUMO

BACKGROUND: Outcomes after surgery for sporadic pancreatic neuroendocrine neoplasms (Pan-NENs) were evaluated. METHODS: This multicentre study included patients who underwent radical pancreatic resection for sporadic non-functioning Pan-NENs. In survival analysis, the risk of mortality in this cohort was analysed in relation to that of the matched healthy Italian population. Relative survival (RS) was calculated as the rate between observed and expected survival. Factors related to RS were investigated using multivariable modelling. RESULTS: Among 964 patients who had pancreatic resection for sporadic non-functioning Pan-NENs, the overall RS rate was 91.8 (95 per cent c.i. 81.5 to 96.5) per cent. 2019 WHO grade (hazard ratio (HR) 5.75 (s.e. 4.63); P = 0.030) and European Neuroendocrine Tumour Society (ENETS) TNM stage (6.73 (3.61); P < 0.001) were independent predictors of RS. The probability of a normal lifespan for patients with G1, G2, G3 Pan-NENS, and pancreatic neuroendocrine carcinomas (Pan-NECs) was 96.7, 54.8, 0, and 0 per cent respectively. The probability of a normal lifespan was 99.8, 99.3, 79.8, and 46.8 per cent for those with stage I, II, III, and IV disease respectively. The overall disease-free RS rate was 73.6 (65.2 to 79.5) per cent. 2019 WHO grade (HR 2.10 (0.19); P < 0.001) and ENETS TNM stage (HR 2.50 (0.24); P < 0.001) significantly influenced disease-free RS. The probability of disease-free survival was 93.2, 84.9, 45.2, and 6.8 per cent for patients with stage I, II, III, and IV disease, and 91.9, 45.2, 9.4, and 0.7 per cent for those with G1, G2, G3 Pan-NENS, and Pan-NECs, respectively. CONCLUSION: A surgical approach seems without benefit for Pan-NECs, and unnecessary for small G1 sporadic Pan-NENs. Surgery alone may be insufficient for stage III-IV and G3 Pan-NENs.


Assuntos
Estadiamento de Neoplasias/métodos , Pancreatectomia/métodos , Neoplasias Pancreáticas/diagnóstico , Seguimentos , Humanos , Itália/epidemiologia , Masculino , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/cirurgia , Estudos Retrospectivos , Taxa de Sobrevida/tendências
4.
Updates Surg ; 73(3): 923-928, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32162271

RESUMO

BACKGROUND: The minimally invasive approach in spleen-preserving distal pancreatectomy has currently been emphasized in benign and pre-malignant pancreatic diseases. The study aims to demonstrate the safety and feasibility of our technique of robotic spleen-preserving distal pancreatectomy (RSPDP) by a stepwise approach. METHODS: The data of consecutive patients presented for RSPDP from 2014 to 2019 at Verona University were retrieved from a prospectively maintained database. The patients were divided into two groups based on the surgical procedure performed, such as Kimura's (KG) or Warshaw's (WG) technique, and then compared. RESULTS: In the study period, 32 patients underwent RSPDP. Twenty-three patients presented for the Kimura procedure (72%), while nine patients underwent the Warshaw procedure (28%). A higher body mass index was found in the KG (26 ± 4 vs. 22 ± 3, p = 0.037). Regarding the pathological data, the WG group differed in the tumor dimension, and the lymph nodes harvested (30 ± 2 vs. 17 ± 10, 9 ± 5 vs. 3 ± 4, p = 0.0028, and p = 0.005, respectively). Notably, no conversions and mortality were recorded. The overall morbidity was 25% ( eight patients) with no difference between the groups (p = 0.820). The mean length of stay was 8 days, and was similar between the groups (p = 0.350). CONCLUSIONS: The present study suggests that RSPDP is a valid option for the treatment of benign or pre-malignant pancreatic diseases of the distal pancreas, with comparable morbidity with the standard treatment and no mortality. Further research is needed to standardize the technique and to assess the immunological, surgical, and financial benefits of the procedure.


Assuntos
Laparoscopia , Neoplasias Pancreáticas , Procedimentos Cirúrgicos Robóticos , Humanos , Pancreatectomia , Neoplasias Pancreáticas/cirurgia , Baço/cirurgia
5.
Eur J Endocrinol ; 182(4): 439-446, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32061159

RESUMO

INTRODUCTION: Management of malignant insulinomas is challenging due to the need to control both hypoglycaemic syndrome and tumor growth. Literature data is limited to small series. AIM OF THE STUDY: To analyze clinico-pathological characteristics, treatments and prognosis of patients with malignant insulinoma. MATERIALS AND METHODS: Multicenter retrospective study on 31 patients (male: 61.3%) diagnosed between 1988 and 2017. RESULTS: The mean age at diagnosis was 48 years. The mean NET diameter was 41 ± 31 mm, and 70.8% of NETs were G2. Metastases were widespread in 38.7%, hepatic in 41.9% and only lymph nodal in 19.4%. In 16.1% of the cases, the hypoglycaemic syndrome occurred after 46 ± 35 months from the diagnosis of originally non-functioning NET, whereas in 83.9% of the cases it led to the diagnosis of NET, of which 42.3% with a mean diagnostic delay of 32.7 ± 39.8 months. Surgical treatment was performed in 67.7% of the cases. The 5-year survival rate was 62%. Overall survival was significantly higher in patients with Ki-67 ≤10% (P = 0.03), insulin level <60 µU/mL (P = 0.015) and in patients who underwent surgery (P = 0.006). Peptide Receptor Radionuclide Therapy (PRRT) was performed in 45.1%, with syndrome control in 93% of patients. CONCLUSIONS: Our study includes the largest series of patients with malignant insulinoma reported to date. The hypoglycaemic syndrome may occur after years in initially non-functioning NETs or be misunderstood with delayed diagnosis of NETs. Surgical treatment and Ki67 ≤10% are prognostic factors associated with better survival. PPRT proved to be effective in the control of hypoglycaemia in majority of cases.


Assuntos
Insulinoma/mortalidade , Tumores Neuroendócrinos/mortalidade , Neoplasias Pancreáticas/mortalidade , Feminino , Humanos , Hipoglicemia/etiologia , Hipoglicemia/mortalidade , Hipoglicemia/patologia , Insulinoma/patologia , Insulinoma/terapia , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/patologia , Tumores Neuroendócrinos/terapia , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
6.
Eur Rev Med Pharmacol Sci ; 20(22): 4719-4724, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27906430

RESUMO

OBJECTIVE: Recurrent acute pancreatitis is an uncommon diagnosis in teenagers. Excluded alcohol and biliary stones, more prevalent aetiologies in these group of patients are genetic pancreatitis, pancreatic duct system abnormalities, neoplasia, traumas and congenital abnormalities of the duodenum such as duodenal duplication or diverticulum. Two reported cases of recurrent pancreatitis associated to midgut malrotation were described in English literature. Bowel malrotation is a difficult diagnosis in a teenager or a young adult and a common delay is documented. Ladd's procedure is largely recognized to be the standard treatment for a symptomatic malrotation. CASE REPORT: Our Report describes in details a case of recurrent pancreatitis, where a late diagnosis of midgut malrotation was obtained and an endoscopic management was attempted. A literature review and an analysis of two previously reported cases were performed to explore a possible aetiopathogenesis of the recurrent acute pancreatitis in patients with midgut malrotation. RESULTS: 24 months of follow-up showed an asymptomatic patient on a free diet, with a mild deranged Liver Functional Tests and a normal Amylase and Lipase. The recurrence of acute pancreatitis has not been observed until the present day. CONCLUSIONS: Recurrent episodes of acute pancreatitis in young adults, without a history of alcohol abuse or evidence of gallstones, might be an atypical presentation of midgut malrotation and it should be in the differential diagnosis. In this case, a Ladd's operation is beneficial and an endoscopic procedure does not obtain advantages.


Assuntos
Anormalidades do Sistema Digestório/complicações , Volvo Intestinal/complicações , Pancreatite/etiologia , Doença Aguda , Feminino , Humanos , Adulto Jovem
7.
G Chir ; 32(4): 199-202, 2011 Apr.
Artigo em Italiano | MEDLINE | ID: mdl-21554851

RESUMO

Endometriosis is a common gynaecological condition which affects women during their reproductive years. It is characterized by ectopic endometrial tissue responding to hormonal changes associated with menstrual cycle. Aetiology is unknown and symptoms are quite aspecific (dysmenorrhoea, pelvic pain, infertility or pelvic mass). Ultrasonography (US) and Magnetic Resonance Imaging (MRI) are accurate diagnostic exams but laparoscopy represents the gold standard in diagnosis and therapy (excision or ablation). Medical treatment pre or postoperatively may be useful prolonging the symptom free interval. In this paper we report the case of a young woman affected by an inguinal mass: diagnostic examinations and histological specimen revealed to be an endometrial focus. We review the literature focusing the diagnostic techniques and relationships between endometriosis and ovarian cancer (endometrioid and clear cell subtypes).


Assuntos
Endometriose , Canal Inguinal , Adulto , Endometriose/diagnóstico , Endometriose/cirurgia , Feminino , Humanos
8.
G Chir ; 31(5): 239-42, 2010 May.
Artigo em Italiano | MEDLINE | ID: mdl-20615368

RESUMO

Mesenteric and retroperitoneal cysts are rare intra-abdominal tumours with an incidence of 1/140.000 in surgery departments and 1/20.000 in paediatric departments. There are no pathognomonic signs or symptoms for the cysts. In the differential diagnosis lymphangiomas, sarcomas, adenocarcinomas and intestinal duplications should be considered. Diagnostic includes abdominal computed tomography, ultrasound and MRI. Barium enema examination or intravenous pyelogram may be used in special cases. Surgical treatment is indicated also in asymptomatic patients; laparoscopic approach is the "gold standard". Laparotomic approach should be used in the cases of impossibility of total enucleation or in the cases of malignant degeneration. Complete enucleation is the treatment of choice for retroperitoneal and mesenteric cysts. If this cannot be accomplished, the alternative should be the excision of the cyst or the marsupialization. In this paper we present a case of young man with a mesenteric cyst mimicking acute appendicitis.


Assuntos
Cisto Mesentérico/diagnóstico , Cisto Mesentérico/cirurgia , Adolescente , Apendicectomia , Apendicite/diagnóstico , Apendicite/cirurgia , Diagnóstico Diferencial , Humanos , Cuidados Intraoperatórios , Masculino , Reoperação , Resultado do Tratamento
9.
Dig Liver Dis ; 39(6): 585-8, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16843740

RESUMO

We report an interesting case of a patient with neither family nor personal history for pancreatic diseases that was admitted to our department in 1982, at the age of 25 years. At that time, medical history, absence of alcohol abuse, and radiological imaging suggested a diagnosis of idiopathic chronic pancreatitis. The patient underwent a left-pancreatectomy, with histological confirmation of chronic pancreatitis. He was asymptomatic until 1988, when episodes of pain arose, requiring a pancreatico-jejunostomy. No further problems ensued until 2004 when radiological investigation following pain-related symptoms revealed enormous dilation of the pancreatic duct. A pylorus-preserving pancreaticoduodenectomy resulting in total pancreatectomy was performed. Histological examination revealed an intraductal papillary mucinous non-invasive carcinoma. Review of the previously resected specimen revealed former misdiagnosis. This tumour usually affects an elderly population and nowadays is recognised as a possible cause of chronic obstructive pancreatitis. This report represents a slippery case of misdiagnosis and demonstrates that follow-up is always mandatory following a diagnosis of idiopathic chronic pancreatitis.


Assuntos
Adenocarcinoma Mucinoso/etiologia , Carcinoma Ductal Pancreático/etiologia , Neoplasias Pancreáticas/etiologia , Pancreatite/complicações , Adenocarcinoma Mucinoso/diagnóstico por imagem , Adenocarcinoma Mucinoso/patologia , Adulto , Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Ductal Pancreático/patologia , Colangiopancreatografia Retrógrada Endoscópica , Colangiopancreatografia por Ressonância Magnética , Humanos , Masculino , Mucinas/isolamento & purificação , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Recidiva , Fatores de Tempo , Tomografia Computadorizada por Raios X
10.
Ann Vasc Surg ; 18(1): 93-9, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14534841

RESUMO

Hepatic artery aneurysms are rare lesions but of significant clinical importance because rupture is associated with elevated mortality. Although diagnosis using CT scanning and, more importantly, angiography has been well defined, the therapeutic choices are less clear. We retrospectively selected patients from 1985 to 2000 who were treated with either traditional surgical or percutaneous techniques. In total we treated six patients, four males and two females. This represents 17.6% of 34 patients treated by us for splanchnic artery aneurysms. The treatment was surgical in two cases (33.3%) and percutaneous in four cases (66.6%). All lesions were successfully treated with exclusion/ablation of the aneurysm. Mortality was nil; in one of the surgical cases we reported a transient hepatic failure and in the endovascular group, one right pleural effusion, one small splenic infarction, and one pseudoaneurysm of the gastroduodenal artery. The first therapeutic strategy to be taken into consideration is always the percutaneous approach. However, surgery still has a role in those cases where the lesion cannot be repaired percutaneously. Based on our own experience (good results, no mortality, and few complications) and in accordance with the literature, it is clear that an aggressive approach is warranted in those patients.


Assuntos
Aneurisma/terapia , Embolização Terapêutica/métodos , Artéria Hepática , Procedimentos Cirúrgicos Vasculares/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
11.
Acta Physiol Scand ; 157(2): 175-86, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8800357

RESUMO

Quadriceps muscle and fibre cross-sectional areas (CSA), torque and neural activation were studied in seven healthy males during 6 months of weight training on alternate days with six series of eight unilateral leg extensions at 80% of one repetition maximum. After training, the quadriceps cross-sectional area increased by 18.8 +/- 7.2% (P < 0.001) and 19.3 +/- 6.7% (P < 0.001) in the distal and proximal regions respectively, and by 13.0 +/- 7.2% (P < 0.001) in the central region of the muscle. Hypertrophy was significantly different between and within the four constituents of the quadriceps. Biopsies of the vastus lateralis at mid-thigh did not show any increase in mean fibre cross-sectional area. Maximum isometric voluntary torque increased by 29.6 +/- 7.9%-21.1 +/- 8.6% (P < 0.01-0.05) between 100 degrees and 160 degrees of knee extension, but no change in the optimum angle (110 degrees-120 degrees) for torque generation was found. A 12.0 +/- 10.8% (P < 0.02) increase in torque per unit area together with a right shift in the IEMG-torque relation and no change in maximum IEMG were observed. Time to peak isometric torque decreased by 45.8% (P < 0.03) but no change in time to maximum IEMG was observed. In conclusion, strength training of the quadriceps results in a variable hypertrophy of its components without affecting its angle-torque relation. The increase in torque per unit area, in the absence of changes in IEMG, may indicate changes in muscle architecture. An increase in muscle-tendon stiffness may account for the decrease in time to peak torque.


Assuntos
Neurônios Motores/fisiologia , Músculo Esquelético/fisiologia , Educação Física e Treinamento , Adulto , Eletromiografia , Humanos , Contração Isométrica/fisiologia , Perna (Membro)/fisiologia , Imageamento por Ressonância Magnética , Masculino , Neurônios Motores/ultraestrutura , Fibras Musculares Esqueléticas/fisiologia , Fibras Musculares Esqueléticas/ultraestrutura , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/inervação
12.
Eur J Appl Physiol Occup Physiol ; 65(5): 438-44, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1425650

RESUMO

The physiological cross-sectional areas (CSAp) of the vastus lateralis (VL), vastus intermedius (VI), vastus medialis (VM) and rectus femoris (RF) were obtained, in vivo, from the reconstructed muscle volumes, angles of pennation and distance between tendons of six healthy male volunteers by nuclear magnetic resonance imaging (MRI). In all subjects, the isometric maximum voluntary contraction strength (MVC) was measured at the optimum angle at which peak force occurred. The MVC developed at the ankle was 746.0 (SD 141.8) N and its tendon component (Ft), given by a mechanical advantage of 0.117 (SD 0.010), was 6.367 (SD 1.113) kN. To calculate the force acting along the fibres (Ff) of each muscle, Ft was divided by the cosine of the angle of pennation and multiplied for (CSAp.sigma CSAp-1), where sigma CSAp was the sum of CSAp of the four muscles. The resulting Ff values of VL, VI, VM and RF were: 1.452 (SD 0.531) kN, 1.997 (SD 0.187) kN, 1.914 (SD 0.827) kN, and 1.601 (SD 0.306) kN, respectively. The stress of each muscle was obtained by dividing these forces for the respective CSAp which was: 6.24 x 10(-3) (SD 2.54 x 10(-3)) m2 for VL, 8.35 x 10(-3) (SD 1.17 x 10(-3)) m2 for VI, 6.80 x 10(-3) (SD 2.66 x 10(-3)) m2 for VM and 6.62 x 10(-3) (SD 1.21 x 10(-3)) m2 for RF. The mean value of stress of VL, VI, VM and RF was 250 (SD 19) kN m-2; this value is in good agreement with data on animal muscle and those on human parallel-fibred muscle.


Assuntos
Joelho , Músculos/fisiologia , Adulto , Humanos , Contração Isométrica , Imageamento por Ressonância Magnética , Masculino , Músculos/anatomia & histologia , Estresse Mecânico , Tendões/fisiologia
13.
Radiother Oncol ; 22(4): 304-7, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1792325

RESUMO

Twenty patients with early breast cancer were treated with external irradiation, delivered with two tangential beams (6 MV X-rays) using a half-beam block (HBB) and 3-D compensating filters. All patients were immobilized with individualized cellulose acetate casts. Patient dosimetry was performed using p-type silicon detectors. Midline doses were calculated by combined entrance and exit dose measurements. The mean ratio of the measured and the prescribed doses was 96.6 +/- 3.8% at the reference point, 96.8 +/- 4.3% at off-axis points on the central plane and 96.8 +/- 7.6% at off-plane points.


Assuntos
Neoplasias da Mama/radioterapia , Calibragem , Relação Dose-Resposta à Radiação , Feminino , Humanos , Imobilização , Garantia da Qualidade dos Cuidados de Saúde , Dosagem Radioterapêutica , Radioterapia Assistida por Computador , Radioterapia de Alta Energia , Silício
14.
Radiol Med ; 80(4 Suppl 1): 46-51, 1990 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-2251418

RESUMO

Individualized Cerrobend beam shapings for high-energy electrons have been utilized in the treatment of superficial tumours located in aesthetic or critical regions. Individualized cellulose acetate masks have been used as immobilization device. Measured transmissions through Cerrobend ranged from 0.5% at 4 MeV to 8.5% at 18 MeV. Phantom dosimetry showed a poor influence of Cerrobend on PDD (percentage depth doses). Output factor variations appeared to depend on electron energy and shielded area. It is very important to perform either empirical measurements or to adopt semiempirical models in order to exactly calculate those output factors. Three clinical examples are presented: the utilization of immobilization device and field shaping are illustrated with the main aim of sparing the dose to critical organs.


Assuntos
Elétrons , Neoplasias Faciais/radioterapia , Proteção Radiológica/instrumentação , Dosagem Radioterapêutica , Humanos , Modelos Estruturais , Radioterapia/métodos
15.
Radiol Med ; 80(4 Suppl 1): 62-72, 1990 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-2251421

RESUMO

The electron beam treatment planning systems, with the availability of more and more developed hardware for complex calculation algorithms, need quality controls of accuracy and comparability of treatment plans from different systems. In this paper three systems have been evaluated; their similar computation algorithms (pencil beam) have been used but in some conditions (beam reconstruction, oblique incidence and dishomogeneity) different results have been drawn. The basic data (PDD, dose profile, etc.) were the same for every system, therefore it has been observed that different results are mainly due to differences in: a) input of parameter values, b) calculation algorithm approximations, c) image acquisitions and elaboration.


Assuntos
Elétrons , Doses de Radiação , Planejamento da Radioterapia Assistida por Computador , Humanos , Modelos Estruturais , Física Nuclear , Controle de Qualidade , Radioterapia/métodos
16.
Artigo em Inglês | MEDLINE | ID: mdl-2583179

RESUMO

Four male subjects aged 23-34 years were studied during 60 days of unilateral strength training and 40 days of detraining. Training was carried out four times a week and consisted of six series of ten maximal isokinetic knee extensions at an angular velocity of 2.09 rad.s-1. At the start and at every 20th day of training and detraining, isometric maximal voluntary contraction (MVC), integrated electromyographic activity (iEMG) and quadriceps muscle cross-sectional area (CSA) assessed at seven fractions of femur length (Lf), by nuclear magnetic resonance imaging, were measured on both trained (T) and untrained (UT) legs. Isokinetic torques at 30 degrees before full knee extension were measured before and at the end of training at: 0, 1.05, 2.09, 3.14, 4.19, 5.24 rad.s-1. After 60 days T leg CSA had increased by 8.5% +/- 1.4% (mean +/- SEM, n = 4, p less than 0.001), iEMG by 42.4% +/- 16.5% (p less than 0.01) and MVC by 20.8% +/- 5.4% (p less than 0.01). Changes during detraining had a similar time course to those of training. No changes in UT leg CSA were observed while iEMG and MVC increased by 24.8% +/- 10% (N.S.) and 8.7% +/- 4.3% (N.S.), respectively. The increase in quadriceps muscle CSA was maximal at 2/10 Lf (12.0% +/- 1.5%, p less than 0.01) and minimal, proximally to the knee, at 8/10 Lf (3.5% +/- 1.2%, N.S.). Preferential hypertrophy of the vastus medialis and intermedius muscles compared to those of the rectus femoris and lateralis muscles was observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Exercício Físico/fisiologia , Músculos/fisiologia , Adulto , Eletromiografia , Humanos , Hipertrofia , Contração Isométrica , Espectroscopia de Ressonância Magnética , Masculino , Músculos/anatomia & histologia , Músculos/patologia , Coxa da Perna
17.
Radiol Med ; 75(5): 433-8, 1988 May.
Artigo em Italiano | MEDLINE | ID: mdl-3375488

RESUMO

Various pathological conditions of the thoracic aorta were studied by MR Imaging in 31 patients: 23 were aneurysms (branching and non-branching), 2 arterio-venous fistulae, 2 aortic prostheses, 2 Marfan's syndromes, 1 coronary sinus aneurysm, and 1 isthmic stenosis. MRI studies were always performed on patients who had been examined by other imaging procedures. A comparative study was carried out on the results of MRI, angiography, computerized tomography, and ultrasounds. The possibility of propedeutic protocol was explored. Our experience, in accordance with the literature on the subject, indicates MRI as the procedure of choice in the study of aneurysms of the thoracic aorta. The advantages offered by MRI--the high natural contrast between circulating blood and the supporting structures, the possibility of obtaining multiplanar images as well as data on intraluminal, parietal, and extraparietal conditions--make it a highly competitive procedure if compared to either CT or angiography. While awaiting further evidence, the use of a propedeutic protocol in non-aneurysmatic diseases is still not advisable, due to insufficient patient population, and to the lack of a consistent literature on the subject.


Assuntos
Doenças da Aorta/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Idoso , Dissecção Aórtica/diagnóstico , Dissecção Aórtica/diagnóstico por imagem , Angiografia , Aorta Torácica , Aneurisma Aórtico/diagnóstico , Aneurisma Aórtico/diagnóstico por imagem , Doenças da Aorta/diagnóstico por imagem , Prótese Vascular , Constrição Patológica , Aneurisma Coronário/diagnóstico , Aneurisma Coronário/diagnóstico por imagem , Humanos , Síndrome de Marfan/diagnóstico , Síndrome de Marfan/diagnóstico por imagem , Pessoa de Meia-Idade
19.
Artigo em Inglês | MEDLINE | ID: mdl-3342791

RESUMO

The maximal strengths of knee extensor (E) and flexor (F) muscles were compared in a group of 6 male subjects aged 24-31 years. Cross-sectional area (CSA) of E and F was evaluated from planimetric measurements of Nuclear Magnetic Resonance (NMR) imaging axial scans, carried out at five levels along the thigh. Maximal CSA for E was found at 2/3 upper femur height and at 1/3 lower femur height for F. Maximum isometric force (MIF) of E was found to be 135% greater than that of F. The maximum CSA of E was found to be 93% larger than CSA of F. The calculated mechanical advantage of the flexors was estimated to be 13.8% higher than that of the knee extensors (0.116 +/- 0.012 and 0.132 +/- 0.005, respectively). However, when MIF of E and F were standardised for their respective CSA, no significant difference was found between their stress: 80.1 +/- 15.5 N.cm-2 for E and 70.5 +/- 7.0 N.cm-2 for F. From the present study, it is concluded that no significant difference exists between the maximum stress of knee extensor and flexor muscles despite large differences in their absolute values of force and CSA and that the NMR imaging technique enables accurate in-vivo determination of the CSA of individual muscles.


Assuntos
Joelho/fisiologia , Músculos/fisiologia , Adulto , Humanos , Contração Isométrica , Imageamento por Ressonância Magnética , Masculino
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