Cancro do Cólon: chegou a altura da RM?

Even if the only currently curative treatment for colon cancer is surgery, recently there has been a growing discussion about the benefit of neoadjuvant chemotherapy (nChT) for patients with locally advanced cancers at increased risk of recurrence, upon recognition of adverse prognostic factors. The first works about nChT in colon cancer have showed promising results.1-3 In specific, results from the FOXTROT trial, designed to evaluate the potential benefits of nChT for patients with locally advanced colon cancer, are greatly expected.1 If that treatment will become standard, pre-operative imaging will become a valuable tool to select patients for nChT.4On the other hand, as some colon tumours are now surgically removed by laparoscopy, is important to recognize those patients in whom laparoscopy might not be appropriated, either because the tumor is bulky or locally advanced.5Therefore, imaging could be important to select: 1) early cancers that may undergo surgical excision directly; 2) locally advanced cancers that may need nChT or require an open approach/radical surgery because of involvement of adjacent organs; and 3) metastatic cancers for which curative surgery is not primarily indicated.6 Traditionally, this selection has been performed by computed tomography (CT), but this method has some important limitations.7 As such, some recent works have focused on the role of magnetic resonance imaging (MRI) in colon cancer staging.4,6,8-1

Tratamento não-cirúrgico do cancro do recto: uma perspectiva

É indiscutível o interesse com que a comunidade científica tem vindo a acolher a estratégia do tratamento não-cirúrgico do cancro do recto, inicialmente divulgada por Habr-Gama, cirurgiã brasileira, e posteriormente replicada de forma mais ou menos semelhante por diversos grupos científicos na Europa e na América do Norte. Tal abordagem preconiza a realização de radioterapia acompanhada de quimioterapia radiossensibilizante e posterior ‘wait-and-see’ ou ‘watchful waiting’ para os pacientes cujos tumores denotem uma resposta clínica completa.Desde logo, um ponto fulcral prende-se com a necessidade de uma abordagem multidisciplinar destes indivíduos, quer em contexto pré-terapêutico, quer na avaliação dos resultados da terapêutica radioterápica

Current concepts for imaging rectal cancer

Tese de doutoramento em Ciências da Saúde (Radiologia e Imagiologia), apresentada à Faculdade de Medicina da Universidade de CoimbraThe present thesis focuses on the study of rectal cancer, which is one of the most frequently diagnosed neoplasms in the Western World, and is also associated with a high mortality rate. Long-term survival is highly dependent on tumor stage at discovery: tumors at an advanced stage at diagnosis are associated with a poor outcome. Accordingly, tumor stage at diagnosis is a guide to treatment strategies. As such, while patients with early cancers usually may achieve cure through surgery alone, those with locally advanced cancers typically undergo preoperative therapy, which is useful for decreasing the tumor stage in order to facilitate curative resection, and to decrease the local recurrence rate. Therefore, the role of the radiologist is to identify tumors within these groups, so that a tailored treatment can be offered to each single patient in order to decrease the probability of local recurrence. In recent years, a paradigm shift toward less invasive treatments has been witnessed, including local excision by TEM or even a – still controversial – deferral from surgery in those patients achieving a complete response from the tumor following preoperative CRT. However, no imaging techniques currently allow an accurate prediction of which tumors will respond satisfactorily to this kind of treatment, and which cases develop a complete response. This is particularly true when using purely morphological imaging methods, and consequently there has been a growing interest in more ‘functional’ imaging techniques, such as DW-MRI or perfusion CT. Magnetic resonance imaging is widely used for the diagnosis and staging of tumors, whereby mainly morphometric macroscopic tissue information is usually obtained. For the assessment of viability and aggressiveness of the tumor or its response to therapy, a method that gives insights at a cellular level would be desirable. DW-MRI provides images whose signal intensity is sensitized to the random motion of free water molecules. The mobility of water molecules within a given voxel is determined by the microscopic cellular structure, i.e., the presence of barriers, such as cell membranes and macromolecules. Thus, DWI has been suggested as a tool to distinguish different tissue compartments based on their different cellular structure. As such, this method offers a theoretical possibility for the assessment of viability of the tumor or its response to therapy. Perfusion CT is a technology that allows measurement of tumor vascular physiology and construction of regional maps of tumor blood flow, blood volume, mean transit time, and vascular permeability–surface area product. This type of study can be repeated at different times to assess tumor response to temporal changes in tumor angiogenesis or anti-angiogenic therapy. The contribution of this study focuses mainly on the aforementioned ‘functional’ techniques. I attempted to bring a new insight into their use in the study of rectal cancer and also to give an own contribution to the consolidation of their routine application in everyday clinical practice. It was possible to demonstrate that both techniques, despite not being ready to fulfil that role yet, may be valuable in characterizing rectal tumors and may provide additional information about response and prognosis. Diffusion-weighted imaging has the potential to become an imaging biomarker in these tumors, as lower ADCs are found in more aggressive tumors. DWI-based volumetry can help in predicting response to neoadjuvant therapy and assessing the presence of complete tumoral response. Perfusion CT can also aid in the prediction of response, as tumors with lower blood flow may respond more favourably to neoadjuvant combined chemoradiation therapy.Na presente tese focamo-nos no estudo do cancro do recto, que constitui uma das neoplasias mais frequentemente diagnosticadas nos países desenvolvidos, associada a uma elevada taxa de mortalidade. A sobrevivência dos pacientes encontra-se intimamente relacionada com o estádio do tumor aquando do diagnóstico: lesões num estádio mais avançado associam-se a um prognóstico mais sombrio. Por seu turno, o estadiamento tumoral constitui a base para a tomada de decisões terapêuticas e, desta forma, pacientes com tumores em estádios mais precoces podem ser curados através de cirurgia, enquanto que aqueles com tumores localmente avançados são via de regra submetidos a terapêutica pré-operatória com o intuito de promover o ‘downstaging’ tumoral e dessa forma facilitar a ressecção cirúrgica com intenção curativa, bem como diminuir a taxa de recidiva local. Consequentemente, o papel do radiologista consiste em classificar as lesões nestes grupos, de forma que o tratamento possa ser ajustado e individualizado para cada paciente no sentido de reduzir a probabilidade de surgir uma recidiva local. Recentemente temos vindo a testemunhar uma alteração no paradigma terapêutico desta patologia, com o aparecimento de tratamentos minimamente invasivos, incluindo a excisão local transanal ou mesmo um adiamento da cirurgia com vigilância regular e periódica naqueles doentes em que se consegue obter uma resposta tumoral completa após terapêutica neoadjuvante com radio- e quimioterapia combinadas (embora tal abordagem seja ainda objecto de considerável controvérsia). Contudo, no presente momento as técnicas de imagem não permitem seleccionar com acuidade suficiente quais os tumores que irão responder de forma satisfatória a este tipo de tratamento nem quais os casos que atingirão uma eventual resposta completa. Estas afirmações são particularmente verdadeiras se considerarmos os métodos de imagem puramente morfológicos, pelo que se tem verificado um interesse crescente por técnicas de imagem mais ‘funcionais’, como sejam a difusão por Ressonância Magnética e a perfusão por Tomografia Computorizada. A Ressonância Magnética é amplamente utilizada no diagnóstico e estadiamento de tumores, fornecendo essencialmente informação morfológica macroscópica acerca dos tecidos. Para avaliação da agressividade e viabilidade do tumor ou da sua resposta à terapêutica, tornar-se-á necessário recorrer a métodos que forneçam informação sobre as características do tumor a nível celular. A intensidade de sinal das estruturas nas imagens de Ressonância Magnética ponderadas em difusão dependem da amplitude do movimento aleatório das moléculas de água, cuja mobilidade em cada voxel é determinada pela estrutura celular microscópica, isto é, pela presença de barreiras que restringem o movimento, como membranas celulares e macromoléculas. Assim sendo, a difusão por Ressonância Magnética pode tornar-se uma ferramenta útil na distinção de diferentes compartimentos teciduais baseando-se na sua distinta estrutura celular, teoricamente oferecendo a possibilidade de avaliar a viabilidade de um tumor e também o seu grau de resposta à terapêutica. A perfusão por Tomografia Computorizada é uma tecnologia que permite a avaliação da fisiologia vascular do tumor e a obtenção de mapas paramétricos de côr do fluxo sanguíneo, volume sanguíneo, tempo de trânsito médio e produto permeabilidade-superfície vascular. Este estudo pode facilmente ser repetido em diferentes tempos para avaliar a resposta do tumor e as alterações da sua angiogénese. A nossa contribuição pessoal centrou-se principalmente em estudos referentes às técnicas de imagem ‘funcionais’ acima mencionadas. Ao fazê-lo, procurámos reforçar o seu papel no estudo do cancro do recto e também, de uma forma despretensiosa, oferecer o nosso próprio contributo para a consolidação do seu uso rotineiro na prática clínica diária no futuro. Foi-nos possível demonstrar que ambas as técnicas supra citadas, apesar de, em nosso entender, ainda incapazes de cumprir tal desiderato, podem desempenhar um relevante papel na caracterização dos tumores rectais e fornecer informação adicional acerca do grau de resposta tumoral e do prognóstico dos doentes. A difusão por Ressonância Magnética tem potencial para se tornar um biomarcador imagiológico destes tumores, pois ADCs mais baixos encontram-se associados a tumores mais agressivos. A volumetria tumoral efectuada com base nas imagens ponderadas em difusão pode auxiliar a prever a resposta tumoral à terapêutica neoadjuvante e a presença de uma resposta tumoral completa. A perfusão por Tomografia Computorizada pode de idêntica forma auxiliar na previsão da resposta, decorrendo do facto de tumores com menor fluxo sanguíneo responderem mais favoravelmente à terapêutica neoajduvante combinada com radio- e quimioterapia

Hepatobiliary fascioliasis

Hepatobiliary fascioliasis is a parasitic disease caused by Fasciola hepatica, which is a trematode that primarily infects cattle and sheep, but may also affect humans in endemic areas.There are two phases of the disease: the acute one - where the parasites infect the liver parenchyma; and the subacute / chronic phase - when the parasites reach the biliary ducts and gallbladder, providing typical imaging findings.Because this disease may mimic several hepatobiliary disorders, misdiagnosis or late diagnosis is a concern. Therefore, knowledge of the typical and specific imaging findings is important in accomplishing a correct diagnosis.The authors describe a case of a 49-year-old male that presented with nonspecific liver symptoms. Liver ultrasound, computed tomography and magnetic resonance imaging showed several typical findings of the disease, which helped achieve the diagnosis

An unusual cause of intra-abdominal calcification: A lithopedion

AbstractWe report a case of a 77-year-old female who was admitted to the emergency department complaining of diffuse abdominal pain for five days, associated with nausea, vomiting and constipation.Physical examination disclosed a large incarcerated umbilical hernia, which was readily apparent on supine abdominal plain films. These also showed a calcified heterogeneous mass in the mid-abdominal region, which was further characterized by CT as a lithopedion (calcified ectopic pregnancy). This is one of the few cases studied on a MDCT equipment, and it clearly enhances the post-processing abilities of this imaging method which allows diagnostic high-quality MIP images.Lithopedion is a rare entity, with less than 300 cases previously described in the medical literature. However, many reported cases corresponded to cases of skeletonization or collections of fetal bone fragments discovered encysted in the pelvic region at surgery or autopsy. It is thus estimated that true lithopedion is a much rarer entity.The diagnosis may be reached by a suggestive clinical history and a palpable mass on physical examination, while the value of modern cross-sectional techniques is still virtually unknown. Ultrasonography may depict an empty uterine cavity and a calcified abdominal mass of non-specific characteristics, and computed tomography or magnetic resonance imaging are able to reach a conclusive diagnosis and may additionally define the involvement of adjacent structures.The differential diagnosis includes other calcified pathologic situations, including ovarian tumors, uterine fibroids, urinary tract neoplasms, inflammatory masses or epiploic calcifications

Diffuse Alveolar Hemorrhage Due to Malignant Arterial Hypertension – an Unusual Manifestation of a Common Disease

Diffuse alveolar hemorrhage is a clinicopathological syndrome that often leads to respiratory failure, with associated hemoptysis and anemia. Chest radiograph presents non-specific findings of perihilar infiltrates, while computed tomography shows ground-glass attenuation or areas of consolidation with interlobular septal thickening. Bronchoalveolar lavage is used to confirm the clinical and radiological suspicion. While vasculitis and other causes of pulmonary renal syndrome are the most common causes of diffuse alveolar hemorrhage, malignant hypertension should be considered in the proper clinical setting. We present a case report of a 51-year-old previously healthy patient that was diagnosed with diffuse alveolar hemorrhage and acute renal failure due to malignant hypertension, through clinical and radiological findings

Tumour ADC measurements in rectal cancer: effect of ROI methods on ADC values and interobserver variability

OBJECTIVES: To assess the influence of region of interest (ROI) size and positioning on tumour ADC measurements and interobserver variability in patients with locally advanced rectal cancer (LARC). METHODS: Forty-six LARC patients were retrospectively included. Patients underwent MRI including DWI (b0,500,1000) before and 6-8 weeks after chemoradiation (CRT). Two readers measured mean tumour ADCs (pre- and post-CRT) according to three ROI protocols: whole-volume, single-slice or small solid samples. The three protocols were compared for differences in ADC, SD and interobserver variability (measured as the intraclass correlation coefficient; ICC). RESULTS: ICC for the whole-volume ROIs was excellent (0.91) pre-CRT versus good (0.66) post-CRT. ICCs were 0.53 and 0.42 for the single-slice ROIs versus 0.60 and 0.65 for the sample ROIs. Pre-CRT ADCs for the sample ROIs were significantly lower than for the whole-volume or single-slice ROIs. Post-CRT there were no significant differences between the whole-volume ROIs and the single-slice or sample ROIs, respectively. The SDs for the whole-volume and single-slice ROIs were significantly larger than for the sample ROIs. CONCLUSIONS: ROI size and positioning have a considerable influence on tumour ADC values and interobserver variability. Interobserver variability is worse after CRT. ADCs obtained from the whole tumour volume provide the most reproducible results. Key Points • ROI size and positioning influence tumour ADC measurements in rectal cancer • ROI size and positioning influence interobserver variability of tumour ADC measurements • ADC measurements of the whole tumour volume provide the most reproducible results • Tumour ADC measurements are more reproducible before, rather than after, chemoradiation treatment • Variations caused by ROI size and positioning should be taken into account when using ADC as a biomarker for tumour response

Tumour ADC measurements in rectal cancer: effect of ROI methods on ADC values and interobserver variability

OBJECTIVES: To assess the influence of region of interest (ROI) size and positioning on tumour ADC measurements and interobserver variability in patients with locally advanced rectal cancer (LARC). METHODS: Forty-six LARC patients were retrospectively included. Patients underwent MRI including DWI (b0,500,1000) before and 6-8 weeks after chemoradiation (CRT). Two readers measured mean tumour ADCs (pre- and post-CRT) according to three ROI protocols: whole-volume, single-slice or small solid samples. The three protocols were compared for differences in ADC, SD and interobserver variability (measured as the intraclass correlation coefficient; ICC). RESULTS: ICC for the whole-volume ROIs was excellent (0.91) pre-CRT versus good (0.66) post-CRT. ICCs were 0.53 and 0.42 for the single-slice ROIs versus 0.60 and 0.65 for the sample ROIs. Pre-CRT ADCs for the sample ROIs were significantly lower than for the whole-volume or single-slice ROIs. Post-CRT there were no significant differences between the whole-volume ROIs and the single-slice or sample ROIs, respectively. The SDs for the whole-volume and single-slice ROIs were significantly larger than for the sample ROIs. CONCLUSIONS: ROI size and positioning have a considerable influence on tumour ADC values and interobserver variability. Interobserver variability is worse after CRT. ADCs obtained from the whole tumour volume provide the most reproducible results. Key Points • ROI size and positioning influence tumour ADC measurements in rectal cancer • ROI size and positioning influence interobserver variability of tumour ADC measurements • ADC measurements of the whole tumour volume provide the most reproducible results • Tumour ADC measurements are more reproducible before, rather than after, chemoradiation treatment • Variations caused by ROI size and positioning should be taken into account when using ADC as a biomarker for tumour response

Outcomes and potential impact of a virtual hands-on training program on MRI staging confidence and performance in rectal cancer

Objectives: To explore the potential impact of a dedicated virtual training course on MRI staging confidence and performance in rectal cancer. // Methods: Forty-two radiologists completed a stepwise virtual training course on rectal cancer MRI staging composed of a pre-course (baseline) test with 7 test cases (5 staging, 2 restaging), a 1-day online workshop, 1 month of individual case readings (n = 70 cases with online feedback), a live online feedback session supervised by two expert faculty members, and a post-course test. The ESGAR structured reporting templates for (re)staging were used throughout the course. Results of the pre-course and post-course test were compared in terms of group interobserver agreement (Krippendorf’s alpha), staging confidence (perceived staging difficulty), and diagnostic accuracy (using an expert reference standard). // Results: Though results were largely not statistically significant, the majority of staging variables showed a mild increase in diagnostic accuracy after the course, ranging between + 2% and + 17%. A similar trend was observed for IOA which improved for nearly all variables when comparing the pre- and post-course. There was a significant decrease in the perceived difficulty level (p = 0.03), indicating an improved diagnostic confidence after completion of the course. // Conclusions: Though exploratory in nature, our study results suggest that use of a dedicated virtual training course and web platform has potential to enhance staging performance, confidence, and interobserver agreement to assess rectal cancer on MRI virtual training and could thus be a good alternative (or addition) to in-person training. // Clinical relevance statement: Rectal cancer MRI reporting quality is highly dependent on radiologists’ expertise, stressing the need for dedicated training/teaching. This study shows promising results for a virtual web-based training program, which could be a good alternative (or addition) to in-person training. // Key Points: • Rectal cancer MRI reporting quality is highly dependent on radiologists’ expertise, stressing the need for dedicated training and teaching. • Using a dedicated virtual training course and web-based platform, encouraging first results were achieved to improve staging accuracy, diagnostic confidence, and interobserver agreement. • These exploratory results suggest that virtual training could thus be a good alternative (or addition) to in-person training

Correction to. Magnetic resonance imaging for clinical management of rectal cancer: Updated recommendations from the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting

Objectives: To update the 2012 ESGAR consensus guidelines on the acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for clinical staging and restaging of rectal cancer. Methods Fourteen abdominal imaging experts from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) participated in a consensus meeting, organised according to an adaptation of the RAND-UCLA Appropriateness Method. Two independent (non-voting) Chairs facilitated the meeting. 246 items were scored (comprising 229 items from the previous 2012 consensus and 17 additional items) and classified as ‘appropriate’ or ‘inappropriate’ (defined by ≥ 80 % consensus) or uncertain (defined by < 80 % consensus). Results: Consensus was reached for 226 (92 %) of items. From these recommendations regarding hardware, patient preparation, imaging sequences and acquisition, criteria for MR imaging evaluation and reporting structure were constructed. The main additions to the 2012 consensus include recommendations regarding use of diffusion-weighted imaging, criteria for nodal staging and a recommended structured report template. Conclusions: These updated expert consensus recommendations should be used as clinical guidelines for primary staging and restaging of rectal cancer using MRI