ABSTRACT In the western world colitis is a common chronic disease and in Sweden the prevalence is around 1%. If a patient has bloody diarrhea it is probably ulcerative proctocolitis or Crohn’s disease, whereas if the diarrhea is watery, it is microscopic colitis. For a diagnosis, the patient has to do a colonoscopy and a colonic biopsy sample has to be taken. The biopsy sample will be sent to a laboratory for sectioning, staining and microscopic analysis. In this study we compared the effects of short and long dehydration time of the sample before the sectioning. We also compared staining with Alcianblue/Van Gieson and Van Gieson alone. Our results showed that a short dehydration time was a milder treatment and made it easier to section the biopsy sample. The comparison of the two methods was unsuccessful because the staining with Alcianblue/Van Gieson failed.

Abstract This study aimed to assess the value of B-mode, nonenhanced and enhanced power Doppler ultrasonography (US), fine-needle aspiration biopsy (FNAB) and magnetic resonance (MR) imaging as adjunctive tools in breast diagnostics. The findings were compared to histology. The mammograms and US images of 84 palpable breast lesions were retrospectively reviewed, 63 of them also blindly. The cytologic reports of 57 lesions were reviewed. Eighty-one (96%) of all the 84 lesions, and 52 of the 53 cancers were visible as a local abnormality at US. The sensitivity, specificity, and overall accuracy of FNAB cytology was 92%, 83%, and 88%, respectively. There were no false negative malignancies in the three modalities combined. Sixty-five lesions not unequivocally benign at mammography were examined with B-mode, unenhanced and enhanced power Doppler US. Vascularity was also analyzed quantitatively. The sensitivity, specificity, and overall accuracy of the morphologic evaluation was 100%, 10%, and 57%, respectively. Rounded lesions were more vascular than spiculated lesions, but vascular assessment was only helpful when supporting a benign morphology. Forty breast lesions were examined with dynamic MR imaging and power Doppler US by obtaining time-signal intensity curves, which were analyzed morphologically and quantitatively. The shape of the MR curve acchieved 90% accuracy in differentiating between benign and malignant lesions. It enabled also differentiation between fibroadenomas and malignancies. The accuracy of the US curve was 38%. Quantitatively, statistically significant differences were found using all the MR variables, except between fibroadenomas and malignancies. Using the US variables, no significant difference was found. Twenty-eight patients (34 breasts) were examined by dynamic low-field and high-field MR imaging. The images were analyzed separately by two radiologists paying attention to lesion morphology and enhancement kinetics. In 27 breasts, results were compared to biopsy. Kappa statistics was used to compare the performance between the MR-scanners and readers. The sensitivity was 100% and 100%, the specificity 82% and 73%, and the accuracy 93% and 89% at low and high field, respectively. The inter-MR-scanner kappa value was 0.77 (substantial agreement), while the inter-observer kappa value was 0.86 and 0.81 at low and high field, respectively (almost perfect agreement).

Abstract The purpose of this study was to analyze the costs incurred during the transitional period when a radiology department is gradually digitalized and magnetic resonance imaging (MRI) is gaining ground as guidance for interventions. The specific aims were: to compare the costs of computed (CR) radiography with the costs of conventional radiography, to analyze the cost structures of procedures and the effects of procedure volumes in a multipurpose interventional MRI (IMRI) unit, to compare the costs of MRI and computed tomography (CT)-guided bone biopsies, and to compare the costs of MRI-guided laser ablation and surgery in the treatment of osteoid osteoma. 34 140 plain-film examinations were analyzed; 3/4 of them were CR and 1/4 conventional radiography. The costs of CR were 9% higher compared to conventional radiography, due to the higher capital cost. In the IMRI unit, 563 diagnostic MRI examinations, 89 MRI-guided interventions, and 39 MRI-guided neurosurgical operations were performed. The cost analyses of the alternative simulation models of IMRI usage showed that the volume of diagnostic imaging had an effect on the unit costs of these procedures. Volume was not such a deterministic factor in interventions due to the high material costs. The volume of the neurosurgical use of IMRI had a major effect on the costs of radiological procedures. The costs of 18 MRI-guided and 12 CT-guided bone biopsies were compared. The cost of MRI-guided biopsy was 2.55-fold compared to CT-guided biopsy, due to the longer procedure time and the expensive MRI-compatible instrumentation. The costs of 7 MRI-guided laser ablations and 6 surgical treatments of osteoid osteoma were compared. The cost of laser ablation was higher than the cost of excision of a superficial osteoid osteoma. The cost of excision of a deep osteoma with metallic fixation was considerably higher, due to the higher material, personnel, and ward costs. Laser ablation diminishes the need for sick days and the duration of restricted weight bearing. In conclusion, a higher cost of a new method should be anticipated. The use of a new method should be justified by other factors, such as better efficiency, accuracy, lack of radiation, or mini-invasiveness.

Abstract Magnetic resonance imaging (MRI) provides high contrast and spatial resolution images in arbitrarily chosen plane without ionizing radiation. These valuable features make it an attractive technique for guiding percutaneous interventional procedures. The purpose of this study was to develop percutaneous abdominal diagnostic and therapeutic procedures in MRI surroundings by evaluating the feasibility, safety and clinical results of specific interventional procedures. The safety and accuracy of MRI-guided abdominal biopsy was evaluated by performing MRI-guided biopsy on 31 patients who were not amenable for an ultrasound-guided biopsy. The locations of the lesions were liver, pancreas, lymph node, retroperitoneal mass, adrenal gland, and spleen. Fine-needle aspiration (FNA) biopsy was performed on all 31 patients; 18 patients underwent both FNA biopsy and cutting needle core biopsy. The sensitivity, specificity and accuracy of FNA and core biopsies were 71, 100 and 81%, and 90, 100 and 94%, respectively. No immediate or late complications occurred. The feasibility and safety of MRI-guided percutaneous drainage of pancreatic fluid collections was assessed by performing ten percutaneous drainages under MRI-guidance. Five of the patients had symptomatic pseudocysts and five had pancreatic abscesses. All procedures were performed with an MRI-compatible drainage kit using the Seldinger technique. All drainage catheters could be successfully placed into the pancreatic fluid collections under MRI-guidance with a mean procedure time of 44 minutes. No immediate complications occurred. The feasibility and safety of MRI-guided percutaneous nephrostomy was evaluated by performing eight nephrostomies with MRI-guidance. The degree of the dilatation of the renal collecting system varied from minimal to severe. All procedures were performed solely under MRI guidance with MRI-compatible instruments. Seven out of eight nephrostomies were successfully performed under MRI guidance; nephrostomy catheter could not be placed in a nondilated system. The mean procedure time was 26 minutes. No major complications occurred during the procedures or follow-up. The safety and effectiveness of MRI-guided percutaneous laser ablation for the treatment of small renal cell carcinoma (RCC) was assessed by treating eight patients with ten tumors with percutaneous MRI-guided laser ablation. All tumors were biopsy-proven RCCs. One to four laser fibers were used per tumor and the tumors were ablated under near real-time MRI control. All but one tumor were successfully ablated in one session. One complication, a myocardial infarction, occurred; all other patients tolerated the procedure well. No local recurrence was discovered during the follow-up with a mean time of 20 months. / Tiivistelmä Magneettikuvauksella elimistön kudoksista ja sairauksista saadaan tarkkaa tietoa missä tahansa kuvaussuunnassa ilman ionisoivaa säteilyä. Näiden ominaisuuksiensa takia magneettikuvaus on houkutteleva menetelmä myös kuvantaohjattujen perkutaanisten toimenpiteiden tekemiseen. Tämän tutkimuksen tavoitteena oli kehittää perkutaanisia vatsan magneettiohjattuja toimenpiteitä. Tämä tehtiin arvioimalla magneettikuvauksen soveltuvuutta, turvallisuutta ja kliinisiä tuloksia erilaisten diagnostisten ja terapeuttisten toimenpiteiden ohjaamisessa. Magneettiohjattujen vatsan neulanäytteiden turvallisuutta ja tarkkuutta arvioitiin 31 potilaalla, joille ei voitu tehdä ultraääniohjattua biopsiaa. Näytteitä otettiin maksasta, haimasta, imusolmukkeista, retroperitoneaalisista kasvaimista, lisämunuaisista ja pernasta. Kaikilta 31 potilaalta otettiin solunäyte, 18 potilaalta otettiin lisäksi kudosnäyte. Solunäytteiden sensitiivisyys oli 71 %, spesifisyys 100 % ja tarkkuus 90 %; kudosnäytteissä vastaavat luvut olivat 90 %, 100 % ja 94 %. Neulanäytteiden otosta ei aiheutunut yhtään komplikaatiota. Magneettiohjauksen soveltuvuutta ja turvallisuutta haiman nestekertymien perkutaanisessa dreneerauksessa arvioitiin kymmenellä potilaalla, joista puolella oli oireileva haiman pseudokysta ja puolella haiman absessi. Kaikki kanavoinnit tehtiin Seldingerin tekniikalla käyttäen magneettiyhteensopivia toimenpidevälineitä. Kaikkien nestekertymien dreneeraus magneettiohjatusti onnistui ilman välittömiä komplikaatioita ja keskimäärin toimenpiteeseen kului aikaa 44 minuuttia. Magneettiohjauksen soveltuvuutta ja turvallisuutta punktionefrostomian tekemiseen tutkittiin kahdeksalla potilaalla, joilla hydronefroosin aste vaihteli vähäisestä vaikeaan. Kaikki toimenpiteet tehtiin magneettiyhteensopivilla toimenpidevälineillä. Magneettiohjatut punktionefrostomiat onnistuivat lukuun ottamatta yhtä potilasta, jolla munuaispikareissa oli vähäistä laajentumaa. Keskimääräinen toimenpideaika oli 26 minuuttia eikä yhtään hoitoa vaativaa komplikaatiota tapahtunut. Magneettiohjatun perkutaanisen munuaissyövän laserpolton turvallisuutta ja tehokkuutta tutkittiin kahdeksalla potilaalla, joilla oli yhteensä kymmenen kasvainta. Kaikki kasvaimet olivat biopsialla varmennettuja munuaissyöpiä. Laserpoltot tehtiin lähes reaaliaikaisessa magneettikuvauskontrollissa käyttäen yhdestä neljään laserkuitua jokaista kasvainta kohden. Yhtä lukuun ottamatta kaikkien kasvainten poltto onnistui yhdellä hoitokerralla. Yhdellä potilaalla hoitoa komplisoi sydäninfarkti, mutta muut sietivät hoidon hyvin. Potilaita seurattiin hoidon jälkeen keskimäärin 20 kuukautta eikä seurannassa todettu yhtään taudin uusiutumaa.

Abstract Interstitial lung diseases (ILD), including interstitial pneumonias (IP), represent disorders with variable degrees of parenchymal inflammation and/or fibrosis offer an ideal model to investigate the histopathological features in relation to the course of these diseases. The most common IP is idiopathic pulmonary fibrosis (IPF) with the histological pattern of usual interstitial pneumonia (UIP) exhibiting the histological hallmark of fibroblast foci (FF). Surgical lung biopsy (SLB) is not usually needed for diagnosis of IPF, but the lung biopsy samples taken by SLB confers the diagnosis in atypical cases. The safety of SLB in IPF/UIP has been a controversial issue. The acute exacerbation occasionally occurs during the course of IPF/UIP, but pathological features related to this event are poorly understood. Recent studies suggest that one important determinant in the pathogenesis of ILDs, as in IPF, is oxidant stress and an imbalance of the redox-state in the lung. Thiol containing redox-regulated proteins which paticipate in the antioxidant defence of the lung include thiorexin (Trx) and gamma-glutamylcysteine synthetase (γGCS), also called glutamate-cysteine ligase (GLCL), the rate-limiting enzyme of glutathione (GSH) synthesis. The goal of this research was to evaluate the safety of SLB and the relationships between the histological findings and the course of IPF/UIP, and to investigate the above mentioned defense mechanisms in a variety of ILDs by means of immmunohistochemical analyses, Western Blotting and immunoelectronmicroscopy. No deaths occurred in the following 30 days after 34 video-assisted thoracoscopic lung biopsy (VATS). The number of FF in the lung sample predicted the survival, but it was not associated with acute exacerbation of IPF/UIP before death. Diffuse alveolar damage was a common feature in autopsy samples. The studied redox regulated defense enzymes were expressed in bronchial epithelium, metaplastic alveolar epithelium and alveolar macrophages, but the fibrotic areas generally showed no expression. In IPF/UIP VATS is a safe diagnostic method and counting the number of FF represents a reproducible and reliable method for predicting patient survival. Alterations in the redox regulated defense enzymes further point to the importance of oxidant burden in the fibrotic lung.

Orientadores: Carlos Arturo Levi D'Ancona, Nelson Rodrigues Netto Júnior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T11:58:20Z (GMT). No. of bitstreams: 1 Zani_EmersonLuis_D.pdf: 2437204 bytes, checksum: a73fbb0add8a13de68169511bc8b989a (MD5) Previous issue date: 2011 / Resumo: A biópsia prostática transretal (BPTR) é um procedimento bem estabelecido utilizado para a obtenção de tecido para o diagnóstico histológico do carcinoma da próstata. Apesar do fato de a BPTR ser geralmente considerada um procedimento seguro, ela pode ser acompanhada por complicações infecciosas e traumáticas. Embora as complicações infecciosas após a BPTR sejam bem conhecidas, há incerteza sobre a necessidade e a eficácia do antibiótico profilático de rotina e uma clara falta de padronização na profilaxia antibiótica para BPTR. O objetivo foi realizar uma revisão sistemática de ensaios clínicos randomizados sobre a profilaxia antibiótica em BPTR para avaliar a eficácia e os efeitos adversos do tratamento antibiótico profilático nessa situação. A pesquisa abrangeu as principais bases eletrônicas: MEDLINE, EMBASE, LILACS e Cochrane Central Register of Controlled Trials (CENTRAL). Especialistas foram consultados e referências de artigos relevantes foram obtidas. Todos os estudos randomizados e controlados (ERCs) de homens que se submeteram à BPTR e receberam antibióticos profiláticos ou placebo / nenhum tratamento foram selecionados, e também todos os ERCs avaliando um tipo de antibiótico contra outro, incluindo doses, vias de administração, freqüência de administração e duração do tratamento antibiótico. A revisão sistemática foi conduzida na Colaboração Cochrane. No geral, mais de 3500 referências foram analisadas e dezenove artigos originais com um total de 3599 pacientes foram incluídos. Nove estudos analisaram antibióticos versus placebo / nenhum tratamento, com todos os resultados favorecendo significativamente o uso de antibióticos (P <0,05 (I2=0%)), incluindo bacteriúria (risco relativo (RR) 0,25 (intervalo de confiança (IC) de 95% de 0,15 a 0,42), bacteremia (RR 0,67, IC 95% 0,49-0,92), febre (RR 0,39, IC 95% 0,23-0,64), infecção do trato urinário (RR 0,37 (IC 95% 0,22-0,62) e hospitalização (RR 0,13 (IC 95% 0,03-0,55)). Diversas classes de antibióticos foram efetivas profilaticamente para a BPTR, e a classe das quinolonas foi a melhor classe analisada, com o maior número de estudos (cinco) e de pacientes (1188). Na comparação "antibiótico versus enema", foram analisados quatro estudos com um número limitado de pacientes. As diferenças entre os grupos não foram significativas. Para "antibiótico versus antibiótico + enema", apenas o risco de bacteremia (RR 0,25, IC 95% 0,08-0,75, P = 0,01) foi reduzido no grupo "antibiótico + enema". Sete estudos relataram os efeitos de antibiótico de curta duração (um dia) versus curso de longa duração (três dias). O uso de antibióticos por longo curso foi significativamente melhor do que o tratamento de curta duração apenas para bacteriúria (RR 2,09, IC 95% 1,17-3,73, P = 0,01 (I2=34%)). Para "dose única versus múltiplas doses", houve maior risco de bacteriúria com dose única (RR 1,98, IC 95% 1,18-3,33, P <0,05 (I2%=7)). Comparando-se a administração oral versus sistêmica - injeção intramuscular (IM) ou intravenosa (IV) - dos antibióticos, não houve diferenças significativas entre os grupos para bacteriúria, febre, ITU e hospitalização. A profilaxia antibiótica é eficaz na prevenção de complicações infecciosas após BPTR. Diversas classes de antibióticos são eficazes profilaticamente para a biópsia da próstata e a classe das quinolonas foi a classe melhor analisada, com o maior número de estudos e de pacientes. Não há dados definitivos para confirmar que os cursos antibióticos de longa duração (três dias) sejam superiores aos tratamentos de curta duração (um dia), ou que o tratamento com doses múltiplas seja superior ao de uma dose única / Abstract: Transrectal prostate biopsy (TRPB) is a well established procedure used to obtain tissue for the histological diagnosis of carcinoma of the prostate. Despite the fact that TRPB is generally considered a safe procedure, it may be accompanied by traumatic and infective complications. Although infective complications after TRPB are well known, there is uncertainty about the necessity and effectiveness of routine prophylactic antibiotics and a clear lack of standardization in antibiotic prophylaxis for TRPB. The objective was to conduct a systematic review of randomized controlled trials on antibiotic prophylaxis in TRPB to evaluate the effectiveness and adverse effects of prophylactic antibiotic treatment in this situation. The search covered the principal electronic databases: MEDLINE, EMBASE, LILACS and the Cochrane Central Register of Controlled Trials (CENTRAL). Experts were consulted and references from the relevant articles were scanned. All randomized, controlled trials (RCTs) of men who underwent TRPB and received prophylactic antibiotics or placebo/no treatment were selected, and all RCTs looking at one type of antibiotic versus another, including comparable dosages, routes of administration, frequency of administration, and duration of antibiotic treatment. The systematic review was conducted in Cochrane Collaboration. Overall, more than 3500 references were considered and nineteen original reports with a total of 3599 patients were included. There were nine trials analyzing antibiotics versus placebo/no treatment, with all outcomes significantly favoring antibiotic use (P < 0.05 (I2 = 0%)), including bacteriuria (relative risk (RR) 0.25 (95% confidence interval (CI) 0.15 to 0.42), bacteremia (RR 0.67, 95% CI 0.49 to 0.92), fever (RR 0.39, 95% CI 0.23 to 0.64), urinary tract infection (RR 0.37 (95% CI 0.22 to 0.62), and hospitalization (RR 0.13 (95% CI 0.03 to 0.55)). Several classes of antibiotics were effective prophylactically for TRPB, and the quinolones were the best analyzed class, with a higher number of studies (five) and patients (1188). For 'antibiotic versus enema', we analyzed four studies with a limited number of patients. The differences between groups were not significant. For "antibiotic versus antibiotic + enema", only the risk of bacteremia (RR 0.25, 95% CI 0.08 to 0.75, P = 0.01) was diminished in the "antibiotic + enema" group. Seven trials reported the effects of short-course (1 day) versus long-course (3 days) antibiotics. Long course was significantly better than short-course treatment only for bacteriuria (RR 2.09, 95% CI 1.17 to 3.73, P = 0.01 ( I2 = 34%)). For "single versus multiple dose", there was significantly greater risk of bacteriuria for singe-dose treatment (RR 1.98, 95% CI 1.18 to 3.33, P < 0.05 (I2 = 7%)). Comparing oral versus systemic administration - intramuscular injection (IM), or intravenous (IV) - of antibiotics, there were no significant differences in the groups for bacteriuria, fever, UTI and hospitalization. Antibiotic prophylaxis is effective in preventing infectious complications following TRPB. Several classes of antibiotics are effective prophylactically for prostate biopsy and the quinolones were the best analyzed class, with a higher number of studies and patients. There is no definitive data to confirm that antibiotics for long-course (three days) are superior to short-course treatments (one day), or that multiple-dose treatment is superior to single-dose / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências

Orientador: Rosemeri de Oliveira Vasconcelos / Resumo: A glândula mamária é o segundo sítio mais comum de desenvolvimento tumoral em cadelas. Uma das formas de estadiamento destes tumores é avaliar a presença ou ausência de metástase à distância, inclusive na medula óssea. Este achado, na Medicina, associa-se a baixa sobrevida de mulheres com tumores mamários, porém na Medicina Veterinária esse estadiamento clínico é mais utilizado para pacientes com linfomas e mastocitomas. Estudos que utilizem a biópsia de medula óssea como método de pesquisa de estadiamento em tumores mamários são escassos. Desta forma o presente estudo teve como objetivo avaliar lesões mamárias e a medula óssea de 36 cadelas, buscando-se células tumorais disseminadas ou focos metastáticos. Para isso realizou-se a análise histopatológica dos tumores de mama, linfonodos e medula óssea dessas cadelas, corados com Hematoxilina e Eosina. Na medula óssea também foram utilizadas a coloração com Tricrômio de Masson, para avaliação de fibrose medular, e a imunohistoquímica, para a pesquisa de micrometástase. O carcinoma em tumor misto grau I fora o mais observado (18,08%), não havendo diferença estatística com relação ao tamanho tumoral e a presença de metástase em linfonodos. Na medula óssea de uma cadela com carcinossarcoma (4,35%) houve marcação citoplasmática de uma provável célula tumoral disseminada, de origem epitelial, com o anticorpo citoqueratina-19 pela imunohistoquímica. Nenhuma das cadelas que apresentou diminuição da celularidade ou fibrose medular (Tric... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Orientador: Antônio José Maria Cataneo / Resumo: Introdução: No melanoma primário, a aplicabilidade da biópsia de linfonodo sentinela (BLS), seguida ou não de esvazimento linfonodal (EL) é conhecida. Na recidiva locorregional (RL) de melanoma, alguns serviços tendem a indicá-la, buscando estadiamento mais acurado para embasar condutas individualizadas aos pacientes, ainda que as evidências sejam insuficientes. Objetivo: Avaliar o sucesso da BLS no encontro do linfonodo sentinela (LNS) e sua positividade na RL. Comparar a sobrevida entre os pacientes com LNS positivo e negativo. Verificar diferença na sobrevida pós EL. Métodos: Revisão sistemática, através das bases MEDLINE via PUBMED, LILACS, SCOPUS, EMBASE e CENTRAL, buscando estudos experimentais e observacionais sobre BLS na RL de melanoma. Desfechos avaliados: sucesso na BLS pelo encontro do LNS, positividade para melanoma no LNS; sobrevida no subgrupo LNS positivo comparado com o negativo; sobrevida livre de doença no subgrupo LNS positivo comparada com o negativo; sobrevida dos pacientes submetidos ao EL. Para metanálises, utilizaram-se RevMan 5.3 e StatsDirect 3.0.121. Resultados: Foram identificados 1872 estudos, destes, seis estudos observacionais foram incluídos, totalizando 449 pacientes. O LNS foi encontrado em 98% das BLS (IC 95-100%, I2=53,7% - seis estudos). LNS com 32% de positividade para melanoma (IC 19-47%, I2= 84,6% - seis estudos). A chance de sobrevida global em cinco anos foi 2,49 vezes maior no subgrupo com LNS negativo (IC 95% 1,41-4,38, I2=0% - qua... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Background: In primary melanoma, the applicability of sentinel lymph node biopsy (SLB), followed or not by complete lymph node dissection (CLND) is known. In locoregional recurrence (LR) of melanoma, some groups may indicate it for more accurate staging to support individualized management, even with scarce evidence. Objective: To evaluate success in SLB and its positivity in LR. Compare survival between patients with positive and negative sentinel lymph node (SLN). Check for survival modification after CLND. Methods: Systematic review through databases such as MEDLINE via PUBMED, LILACS, SCOPUS, EMBASE and CENTRAL, searching for experimental and observational studies on SLB in melanoma LR. Outcomes assessed: success in SLB by finding the SLN, positivity for melanoma in the SLN; survival in the positive SLN subgroup compared to the negative one; disease-free survival in the positive versus negative SLN subgroup; survival of patients undergoing CLND. For meta-analyzes, RevMan 5.3 and StatsDirect 3.0.121 were used. Results: The total number of patients in six observational studies was 449, over 1872 studies indentified. The SNL was found in 98% of SLB (95-100% CI, I2 = 53.7%, 6 studies). SLB detected 32% positivity for melanoma on SNL (CI 19-47%, I2 = 84.6%, 6 studies). The chance of five year overall survival was 2,49 higher in the negative SNL subgroup (95% CI 1.41-4.38, I2 = 0%, 4 studies). Meta-analyzes were not performed due to lack of objective data for disease-free survi... (Complete abstract click electronic access below) / Doutor

Le cancer de la prostate est le premier cancer en fréquence et la 3ème cause de mortalité chez l’homme en France, enjeu majeur de santé publique avec environ 50 000 nouveaux cas diagnostiqués par an. Son diagnostic est suspecté devant un toucher rectal anormal ou une élévation du taux de l’antigène spécifique prostatique (PSA). Les biopsies prostatiques randomisées, écho-guidées, sont actuellement recommandées en première intention pour confirmer le diagnostic et définir la localisation, le volume, et l’agressivité tumorale par le score de Gleason. Les difficultés de l’enseignement du geste de biopsie prostatique par compagnonnage, sans retour réellement quantifié sur la répartition des biopsies, sont une des explications du manque de précision des biopsies.C’est dans ce contexte qu’a été développé le simulateur Biopsym, environnement pédagogique permettant l’enseignement des biopsies prostatiques à l’aide de 7 exercices et d’un module simulant une série de 12 biopsies randomisées. Plusieurs niveaux d’assistance et un retour sur les performances réalisées par l’apprenant sont proposés. Une première étude avait permis de valider l’apparence et le contenu du simulateur, mais sa capacité à discriminer experts et novices (construit) n’avait pu être mise en évidence notamment en raison d’un manque de réalisme. Au cours de cette thèse, 2 nouvelles études de validation ont donc été réalisées sur une nouvelle version du simulateur. La première a permis d’en valider le construit. La seconde a permis de valider le transfert des compétences, c’est à dire la capacité des étudiants à reproduire les compétences acquises sur le simulateur en situation réelle. / Prostate cancer is the most common malignancy and the 3rd cause of death among men in France. It is a major public health problem with around 50 000 new cases diagnosed each year. The diagnosis is suspected based on an abnormal digital rectal examination or an increase in the prostatic specific antigen level (PSA). Systematic, randomized, ultrasound-guided prostate biopsies are currently recommended first-line to confirm the diagnosis and define the tumor location, volume, and aggressiveness using the Gleason grading system. The conventional training method, based on mentoring, without quantitative feedback on the distribution of the biopsies, has limitations which can partly explain the lack of precision offered by systematic prostate biopsies.The Biopsym simulator was designed in this context to enhance prostate biopsy teaching through 7 exercises and a module replicating the performance of a 12-core systematic biopsy scheme. Several levels of assistance can be offered and a performance feedback is provided. A first validation study allowed to validate face, content and reliability of the simulator, but failed to prove its ability to discriminate between experts and novices (construct validity), in part due to a lack of realism. Two new validation studies on the new version of the simulator were set up during this thesis. The first one allowed for validation of the construct. The second one was able to demonstrate the transfer of skills acquired on the simulator under real-life conditions.

Objectives: MRI is of great clinical utility for the guidance of special diagnostic and therapeutic interventions. The majority of such procedures are performed iteratively (\"in-and-out\") in standard, closed-bore MRI systems with control imaging inside the bore and needle adjustments outside the bore. The fundamental limitations of such an approach have led to the development of various assistance techniques, from simple guidance tools to advanced navigation systems. The purpose of this work was to thoroughly assess the targeting accuracy, workflow and usability of a clinical add-on navigation solution on 240 simulated biopsies by different medical operators. Methods: Navigation relied on a virtual 3D MRI scene with real-time overlay of the optically tracked biopsy needle. Smart reference markers on a freely adjustable arm ensured proper registration. Twenty-four operators – attending (AR) and resident radiologists (RR) as well as medical students (MS) – performed well-controlled biopsies of 10 embedded model targets (mean diameter: 8.5 mm, insertion depths: 17-76 mm). Targeting accuracy, procedure times and 13 Likert scores on system performance were determined (strong agreement: 5.0). Results: Differences in diagnostic success rates (AR: 93%, RR: 88%, MS: 81%) were not significant. In contrast, between-group differences in biopsy times (AR: 4:15, RR: 4:40, MS: 5:06 min: sec) differed significantly (p<0.01). Mean overall rating was 4.2. The average operator would use the system again (4.8) and stated that the outcome justifies the extra effort (4.4). Lowest agreement was reported for the robustness against external perturbations (2.8). Conclusions: The described combination of optical tracking technology with an automatic MRI registration appears to be sufficiently accurate for instrument guidance in a standard (closed-bore) MRI environment. High targeting accuracy and usability was demonstrated on a relatively large number of procedures and operators. Between groups with different expertise there were significant differences in experimental procedure times but not in the number of successful biopsies.