Whole-Body Magnetic Resonance Imaging in the Oncology Setting: An Overview and Update on Recent Advances.

Whole-body magnetic resonance imaging is becoming an important tool in oncology as a nonirradiating imaging technique since recent technological advances allowed the incorporation of high-quality imaging in an adequate time. Moreover, the noninjection of radioisotope/intravenous contrast, low cost compared with traditional nuclear medicine techniques, and fast acquisition times are another distinct feature. Thus, the purpose of this article is to review the whole-body magnetic resonance imaging protocol and its main applications in the oncology setting.

Safety and feasibility of radiofrequency ablation for treatment of Bosniak IV renal cysts.

PURPOSE: To describe our initial experience with radiofrequency ablation (RFA) of Bosniak IV renal cysts. MATERIALS AND METHODS: From 2010 to 2014, 154 renal tumor cases were treated with percutaneous thermal ablation, of which 10 cases (6.4%) from nine patients were complex renal cysts and were treated with radiofrequency ablation. RESULTS: All complex cysts were classified as Bosniak IV (four women and five men; mean age: 63.6 yrs, range: 33-83 years). One patient had a single kidney. Lesion size ranged from 1.5 to 4.1cm (mean: 2.5cm) and biopsy was performed on four cysts immediately before the procedure, all of which were malignant (two clear cell and two papillary carcinoma). Mean volume reduction of complex cysts was 25% (range: 10-40%). No patients required retreatment with RFA and no immediate or late complications were observed. The follow-up of Bosniak IV cysts had a median of 27 months (interquartile range [IQR], 23 to 38) and no recurrence or significant loss of renal function were observed. CONCLUSIONS: Mid-term follow-up of the cases in our database suggests that image-guided percutaneous RFA can treat Bosniak IV cysts with very low complication rates and satisfactorily maintain renal function.

Abdominal gunshot wounds: multi-detector-row CT findings compared with laparotomy: a prospective study.

The purpose of this study was to access the accuracy of multi-detector-row computed tomography (MDCT) in diagnosing injuries in hemodynamically stable abdominal gunshot wound victims (AGWV). Triple-contrast MDCT was performed in hemodynamically stable AGWV during a 20-month prospective diagnostic accuracy study. Thirty-one patients (30 males, 1 female; mean age, 24.3 years) were evaluated by two radiologists for evidence of injury to solid and hollow organs, vascular structures, urinary bladder, diaphragm, fractures, and general findings (free fluid, pneumoperitoneum, and mesentery lesions). All of the patients underwent laparotomy, and prevalence, sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. No statistically significant differences between radiologists were found. All of the solid and hollow organ lesions, vascular lesions, and general findings were detected. One of the four urinary bladder lesions was missed by MDCT, leading in this case to a sensitivity of 75%, specificity of 100%, positive predictive value of 100%, negative predictive value of 96.4%, and accuracy of 96.8% (p = 0.001). One of the eight diaphragm lesions was missed by MDCT, and its sensitivity was 87.5%, specificity was 100%, positive predictive value was 100%, negative predictive value was 95.8%, and accuracy was 96.8% (p < 0.001). Fractures were diagnosed in 74.4% of the patients (24 of 31). Fourteen (43.2%) patients demonstrated non-therapeutic laparotomy, in which minor lesions could have been managed conservatively. We concluded that MDCT is an accurate imaging method in evaluating selected AGWV, providing trusted information for emergency room physicians.

Diagnostic Yield of Computed Tomography-Guided Procedures for Spondylodiscitis.

PURPOSE: To identify the diagnostic yield and predictive factors for microbiological diagnosis in patients with spondylodiscitis through computed tomography (CT)-guided biopsy or aspiration. MATERIALS AND METHODS: A retrospective review of 102 patients with suspected spondylodiscitis who underwent CT-guided procedures in an 8-year period was conducted. Analyzed variables were demographic data, C-reactive protein, pre-biopsy MRI findings, prior antibiotic use, site of biopsy/aspiration, histopathological findings, culture results and radiation dose. RESULTS: The culture yield among all sites was 56%, 85.6% for paravertebral/discal fluid aspiration, 66.7% for disk-only biopsy, 52.9% for paravertebral soft tissue biopsy, and 39.6% for endplate bone-disk unit. Patients with paravertebral/disk collection on MRI had better yields when submitted to fluid aspiration instead of biopsy of other sites (78.9% vs. 36.6%; p = 0,006). Pyogenic etiology corresponded to 68.3% of cases and Staphylococcus aureus was the most common agent. Prior antibiotics exposure was associated with a lower yield (66.2% vs. 40.9%, p = 0,016). CONCLUSIONS: CT-guided procedures are safe and well-tolerated in patients with suspected spondylodiscitis, with good microbiologic yield particularly in the presence of paravertebral/discal abscess.

Radiomic analysis of MRI to Predict Sustained Complete Response after Radiofrequency Ablation in Patients with Hepatocellular Carcinoma - A Pilot Study.

OBJECTIVES: To investigate whether quantitative textural features, extracted from pretreatment MRI, can predict sustained complete response to radiofrequency ablation (RFA) in patients with hepatocellular carcinoma (HCC). METHODS: In this IRB-approved study, patients were selected from a maintained six-year database of consecutive patients who underwent both pretreatment MRI imaging with a probable or definitive imaging diagnosis of HCC (LI-RADS 4 or 5) and loco-regional treatment with RFA. An experienced radiologist manually segmented the hepatic nodules in MRI arterial and equilibrium phases to obtain the volume of interest (VOI) for extraction of 107 quantitative textural features, including shape and first- and second-order features. Statistical analysis was performed to evaluate associations between textural features and complete response. RESULTS: The study consisted of 34 patients with 51 treated hepatic nodules. Sustained complete response was achieved by 6 patients (4 with single nodule and 2 with multiple nodules). Of the 107 features from the arterial and equilibrium phases, 20 (18%) and 25 (23%) achieved AUC >0.7, respectively. The three best performing features were found in the equilibrium phase: Dependence Non-Uniformity Normalized and Dependence Variance (both GLDM class, with AUC of 0.78 and 0.76, respectively) and Maximum Probability (GLCM class, AUC of 0.76). CONCLUSIONS: This pilot study demonstrates that a radiomic analysis of pre-treatment MRI might be useful in identifying patients with HCC who are most likely to have a sustained complete response to RFA. Second-order features (GLDM and GLCM) extracted from equilibrium phase obtained highest discriminatory performance.

Percutaneous radiofrequency ablation on a Xp11.2 Translocation Renal Cell Carcinoma: A case report.

Xp11.2 Translocation Renal Cell Carcinoma is a very rare subtype of renal neoplasm. The present report describes the first confirmed reported case of percutaneous ablation of this subtype of tumor. The patient presented an aggressive local recurrence 12 months after the procedure, with an infiltrative large mass occupying almost the whole kidney. The patient was submitted to radical nephrectomy. As the use of ablative methods expands, the treatment of rare renal tumor subtypes, which can present unusual clinical outcomes, may become more frequent. It is essential that these uncommon outcomes are promptly recognized, allowing early therapeutic salvage approaches.

Lung radiofrequency ablation: post-procedure imaging patterns and late follow-up.

PURPOSE: To describe expected imaging features on chest computed tomography (CT) after percutaneous radiofrequency ablation (RFA) of lung tumors, and their frequency over time after the procedure. METHODS: In this double-center retrospective study, we reviewed CT scans from patients who underwent RFA for primary or secondary lung tumors. Patients with partial ablation or tumor recurrence during the imaging follow-up were not included. The imaging features were assessed in pre-defined time points: immediate post-procedure, ≤4 weeks, 5-24 weeks, 25-52 weeks and ≥52 weeks. Late follow-up (3 and 5 years after procedure) was assessed clinically in 48 patients. RESULTS: The study population consisted of 69 patients and 144 pulmonary tumors. Six out of 69 (9%) patients had primary lung nodules (stage I) and 63/69 (91 %) had metastatic pulmonary nodules. In a patient-level analysis, immediately after lung RFA, the most common CT features were ground glass opacities (66/69, 96 %), consolidation (56/69, 81 %), and hyperdensity within the nodule (47/69, 68 %). Less than 4 weeks, ground glass opacities (including reversed halo sign) was demonstrated in 20/22 (91 %) patients, while consolidation and pleural thickening were detected in 17/22 patients (77 %). Cavitation, pneumatocele, pneumothorax and pleural effusions were less common features. From 5 weeks onwards, the most common imaging features were parenchymal bands. CONCLUSIONS: Our study demonstrated the expected CT features after lung RFA, a safe and effective minimally invasive treatment for selected patients with primary and secondary lung tumors. Diagnostic and interventional radiologists should be familiar with the expected imaging features immediately after RFA and their change over time in order to avoid misinterpretation and inadequate treatments.

State-of-the-art in radiomics of hepatocellular carcinoma: a review of basic principles, applications, and limitations.

Radiomics is a new field in medical imaging with the potential of changing medical practice. Radiomics is characterized by the extraction of several quantitative imaging features which are not visible to the naked eye from conventional imaging modalities, and its correlation with specific relevant clinical endpoints, such as pathology, therapeutic response, and survival. Several studies have evaluated the use of radiomics in patients with hepatocellular carcinoma (HCC) with encouraging results, particularly in the pretreatment prediction of tumor biological characteristics, risk of recurrence, and survival. In spite of this, there are limitations and challenges to be overcome before the implementation of radiomics into clinical routine. In this article, we will review the concepts of radiomics and their current potential applications in patients with HCC. It is important that the multidisciplinary team involved in the treatment of patients with HCC be aware of the basic principles, benefits, and limitations of radiomics in order to achieve a balanced interpretation of the results toward a personalized medicine.

Management of Hepatocellular Carcinoma during the COVID-19 Pandemic - São Paulo Clínicas Liver Cancer Group Multidisciplinary Consensus Statement.

More than 18 million people in 188 countries have been diagnosed as having coronavirus disease (COVID-19), and COVID-19 has been responsible for more than 600,000 deaths worldwide. Brazil is now the second most affected country globally. Faced with this scenario, various public health measures and changes in the daily routines of hospitals were implemented to stop the pandemic. Patients with hepatocellular carcinoma (HCC) are at an increased risk for severe COVID-19 as they present with two major diseases: cancer and concomitant chronic liver disease. The COVID-19 pandemic can significantly impact the management of HCC patients from diagnosis to treatment strategies. These patients need special attention and assistance at this time, especially since treatment for tumors cannot be delayed in most cases. The aim of this guideline was to standardize the management of HCC patients during the COVID-19 pandemic. This document was developed, on the basis of the best evidence available, by a multidisciplinary team from Instituto do Câncer do Estado de São Paulo (ICESP), and Instituto Central of the Hospital das Clínicas da Universidade de São Paulo (HC-FMUSP), which are members of the São Paulo Clínicas Liver Cancer Group.

BRAZILIAN SOCIETY OF HEPATOLOGY UPDATED RECOMMENDATIONS FOR DIAGNOSIS AND TREATMENT OF HEPATOCELLULAR CARCINOMA.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. The Brazilian Society of Hepatology (SBH) published in 2015 its first recommendations about the management of HCC. Since then, new data have emerged in the literature, prompting the governing board of SBH to sponsor a single-topic meeting in August 2018 in São Paulo. All the invited experts were asked to make a systematic review of the literature reviewing the management of HCC in subjects with cirrhosis. After the meeting, all panelists gathered together for the discussion of the topics and the elaboration of updated recommendations. The text was subsequently submitted for suggestions and approval of all members of the Brazilian Society of Hepatology through its homepage. The present manuscript is the final version of the reviewed manuscript containing the recommendations of SBH.

18F-FDG PET/CT performed immediately after percutaneous ablation to evaluate outcomes of the procedure: preliminary results.

OBJECTIVE: To determine whether 18F-fluorodeoxyglucose positron emission tomography/computed tomography performed immediately after percutaneous ablation (iPA 18F-FDG PET/CT) is useful in evaluating the outcomes of the procedure. MATERIALS AND METHODS: This was a retrospective study of 20 patients (13 males, 7 females; mean age, 65.8 ± 12.1 years) submitted to percutaneous ablation of metastases. All of the lesions treated had shown focal uptake on a 18F-FDG PET/CT scan obtained at baseline. The primary tumors were mainly colorectal cancer (in 45%) or lung cancer (in 40%). iPA 18F-FDG PET/CT was performed to identify any residual viable tumor cells. The treatment was considered a success (no viable tumor cells present) if no uptake of 18F-FDG was noted on the iPA 18F-FDG PET/CT scan. RESULTS: Twenty-six lesions were submitted to percutaneous ablation with either cryoablation (n = 7) or radiofrequency ablation (n = 19). The mean lesion diameter was 2.52 ± 1.49 cm. For the detection of viable tumor cells, iPA 18F-FDG PET/CT had a sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 66.7%, 95%, 88.5%, 80%, and 90.5%, respectively. There was a significant correlation between the iPA 18F-FDG PET/CT findings and the results of the follow-up studies (kappa = 0.66; p < 0.01). CONCLUSION: iPA 18F-FDG PET/CT studies appear to constitute a useful means of evaluating the outcomes of percutaneous ablation. By detecting residual viable tumor cells, this strategy might allow early re-intervention, thus reducing morbidity. Studies involving larger numbers of patients are needed in order to confirm our findings.

OBJETIVO: Demonstrar se a tomografia por emissão de pósitrons acoplada a tomografia computadorizada usando-se fluorodesoxiglicose marcada com flúor-18 realizada imediatamente após ablação percutânea (iAP 18F-FDG PET/CT) pode ser útil na avaliação do resultado desse tratamento. MATERIAIS E MÉTODOS: Foram avaliados, retrospectivamente, 20 pacientes (13 homens e 7 mulheres; média de idade: 65,8 ± 12,1 anos) submetidos a ablação percutânea de metástases apresentando captação de 18F-FDG no exame de PET/CT. Os tumores primários foram, principalmente, câncer colorretal (45%) ou câncer de pulmão (40%). A iAP 18F-FDG PET/CT foi realizada para avaliar tumor residual viável. O tratamento foi considerado sucesso (sem lesão viável) se nenhuma captação de 18F-FDG fosse observada na iAP 18F-FDG PET/CT. RESULTADOS: Vinte e seis lesões foram submetidas a ablação percutânea por meio de crioablação (n = 7) ou radiofrequência (n = 19). O tamanho médio das lesões era de 2,52 ± 1,49 cm. A iAP 18F-FDG PET/CT detectou tumor viável com sensibilidade, especificidade, acurácia, valor preditivo positivo e valor preditivo negativo de 66,7%, 95%, 88,5%, 80% e 90,5%, respectivamente. Houve correlação significativa entre os achados da iAP 18F-FDG PET/CT e os resultados do seguimento clínico dos pacientes (kappa = 0,66; p < 0,01). CONCLUSÃO: A iAP 18F-FDG PET/CT é capaz de avaliar o resultado da ablação percutânea e poderá permitir reintervenção precoce de lesões residuais viáveis, reduzindo a morbidade. Um número maior de pacientes é necessário para confirmar esses achados.

Diagnostic performance of magnetic resonance to assess treatment response after neoadjuvant therapy in patients with locally advanced rectal cancer.

PURPOSE: Our study aimed to evaluate the diagnostic performance of rectal magnetic resonance imaging (MRI) for local restaging in patients with non-metastatic locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (CRT) using surgical histopathology of total mesorectal excision as the reference standard. METHODS: Ninety-five patients with LARC who underwent rectal MRI after CRT between January 2014 and December 2016 were included. Accuracy, sensitivity, specificity, positive, and negative predictive value for local staging regarding T-stage, N-stage, circumferential resection margin, and MRI tumor regression grade (ymriTRG) were calculated, and inter-test agreements were assessed. RESULTS: 22/95 (23.2%) patients had radiological complete response (rCR), whereas 20/95 (21.1%) had pathological complete response (pCR). Among the patients with pCR, 11/20 (55%) had rCR. Fair agreement was demonstrated between ymriTRG and pathological TRG (ypTRG) (κ = 0.255). The sensitivity and specificity for detection of pCR were 61.1% (95% CI 35.7-82.7) and 89.6% (95% CI 80.6-95.4). For the detection of ypTRG grades 1 and 2, the corresponding values were 67.2% (95% CI 54.3-78.4) and 51.6 (95% CI 33.1-69.8). The accuracy of ymriTRG was 24.2% (95% CI 15.6-32.8). Inter-test agreement in TRG between MRI and pathology was overall fair (κ = 0.255) and slight (κ = 0.179), if TRG 1 + 2. CONCLUSION: Qualitative assessment on MRI for diagnosing pCR showed moderate sensitivity and high specificity, whereas the diagnosis of TRG had moderate sensitivity and low specificity with slight to fair inter-test agreement when compared with pathological specimens.

RECOMMENDATIONS FOR INVASIVE PROCEDURES IN PATIENTS WITH DISEASES OF THE LIVER AND BILIARY TRACT: REPORT OF A JOINT MEETING OF THE BRAZILIAN SOCIETY OF HEPATOLOGY (SBH), BRAZILIAN SOCIETY OF DIGESTIVE ENDOSCOPY (SOBED) AND BRAZILIAN SOCIETY OF INTERVENTIONAL RADIOLOGY AND ENDOVASCULAR SURGERY (SOBRICE).

Liver and biliary tract diseases are common causes of morbidity and mortality worldwide. Invasive procedures are usually performed in those patients with hepatobiliary diseases for both diagnostic and therapeutic purposes. Defining proper indications and restraints of commonly used techniques is crucial for proper patient selection, maximizing positive results and limiting complications. In 2018, the Brazilian Society of Hepato-logy (SBH) in cooperation with the Brazilian Society of Interventional Radiology and Endovascular surgery (SOBRICE) and the Brazilian Society of Digestive Endoscopy (SOBED) sponsored a joint single-topic meeting on invasive procedures in patients with hepatobiliary diseases. This paper summarizes the proceedings of the aforementioned meeting. It is intended to guide clinicians, gastroenterologists, hepatologists, radiologists, and endoscopists for the proper use of invasive procedures for management of patients with hepatobiliary diseases.

Systemic Air Embolism after Percutaneous Lung Biopsy: A Manageable Complication.

CT-guided percutaneous biopsy is a resourceful and widely used tool to evaluate pulmonary nodules that frequently avoids costly and unnecessary surgeries. Severe complications occur in less than 1% of cases and include gas embolism, which is rarely documented. We report a case of gas embolism after transthoracic biopsies and discuss the pathophysiology and the benefits of early diagnosis and proper management.

Paracoccidioidomycosis in a liver transplant recipient.

Paracoccidioidomycosis is a granulomatous systemic mycosis that is endemic in Latin America; it is an extremely rare infection following solid organ transplantation. In this study, we describe the first report of disseminated paracoccidioidomycosis in a 3-year-old girl who underwent liver transplantation 2 years previously. The radiologic diagnosis and patient follow-up are described. In addition, we review the clinical evolution and treatment regimens for this infection.

Hepatocyte-specific contrast agent-enhanced magnetic resonance cholangiography: perioperative evaluation of the biliary tree.

A large number of gadolinium chelates have recently been tested in clinical trials. Some of those have already been approved for clinical use in the United States and Europe. Thus, new diagnostic perspectives have been incorporated into magnetic resonance imaging studies. Among such gadolinium chelates are hepatobiliary-specific contrast agents (HSCAs), which, due to their property of being selectively taken up by hepatocytes and excreted by the biliary ducts, have been widely used for the detection and characterization of focal hepatic lesions. In comparison with conventional magnetic resonance cholangiography (MRC), HSCA-enhanced MRC provides additional information, with higher spatial resolution and better anatomic evaluation of a non-dilated biliary tree. A thorough anatomic assessment of the biliary tree is crucial in various hepatic surgical procedures, such as complex resection in patients with colorectal cancer and living-donor liver transplantation. However, the use of HSCA-enhanced MRC is still limited, because of a lack of data in the literature and the poor familiarity of radiologists regarding its main indications. This pictorial essay aims to demonstrate the use of HSCA-enhanced MRC, with particular emphasis on anatomical analysis of the biliary tree, clinical applications, and the most important imaging findings.

Recentemente, um grande número de quelantes de gadolínio tem sido testado em ensaios laboratoriais. Alguns deles já foram inclusive aprovados para uso clínico nos Estados Unidos e na Europa. Com isso, novas perspectivas diagnósticas foram incorporadas nos estudos de ressonância magnética. Dentre estes quelantes de gadolínio, os contrastes hepatobiliares específicos (CHBEs) têm sido amplamente utilizados para a caracterização e detecção de lesões focais hepáticas, essencialmente pela propriedade de serem captados pelos hepatócitos e excretados na via biliar. Além disso, os CHBEs trouxeram novas informações na avaliação da árvore biliar quando comparados à colangiorressonância convencional, proporcionando uma maior resolução espacial e melhor avaliação da anatomia da árvore biliar não dilatada. A avaliação da anatomia biliar é de fundamental importância em cirurgias hepáticas, como ressecções complexas em tumores colorretais ou no transplante hepático com doador vivo, porém, o uso dos CHBEs ainda é restrito para estes propósitos. Em razão da escassa literatura sobre o tema e da pouca familiaridade dos radiologistas com as principais indicações, o presente ensaio iconográfico tem por objetivo demonstrar o uso de CHBEs na avaliação perioperatória das vias biliares, ressaltando a avaliação anatômica, as indicações e os principais achados de imagem.