Imaging of advanced renal cell carcinoma

Novel Retroperitoneal Neovascularity Scoring System in Renal Cell Carcinoma Tumor Staging

Purpose: Renal cell carcinoma (RCC) is the most common type of kidney cancer worldwide. Although radiologists assess enhancement patterns of renal tumors to predict tumor pathology report, to our knowledge, no formal scoring system has been created and validated to assess the level of neovascularity in RCC, despite its critical role in cancer metastases. In this study, we characterized and analyzed the level of angiogenesis in tumor-burdened kidneys and their benign counterparts. We then created and validated a scoring scale for neovascularity that can help predict tumor staging for RCC. Methods: After Institutional Review Board approval, the charts of patients who had undergone operation for RCC between January 13, 2014 and February 4, 2020 were retrospectively reviewed for inclusion in this study. Inclusion criteria were a diagnosis of RCC, simple/radical nephrectomy, preoperative contrast-enhanced CT scans, and complete pathology reports. Neovascularity was scored on a scale of 0-4 where 0 = no neovascularity detected, 1 = a single vessel <3 mm wide, 2 = a single vessel ≥3 mm wide, 3 = multiple vessels <3 mm wide, and 4 = multiple vessels ≥3 mm wide. Results: A total of 227 patients were included in this study. Most of the tumor pathology reports were clear cell carcinoma, regardless of tumor staging. The average neovascularity score was 1.07 for pT1x tumors, 2.83 for pT2x tumors, and 3.04 for pT3x tumors. There was a significant difference in neovascularity score between pT1x and pT2x tumors (p = 0.0046), pT1x and pT3x tumors (p < 0.0001), and benign kidneys and kidneys with RCC (p < 0.0001). Conclusion: Our novel vascular scoring system for RCC demonstrates significant correlation with RCC pathological tumor staging. This scoring system may be utilized as part of a comprehensive radiological assessment of renal tumors, potentially improving tumor characterization and clinical decision making.

Contemporary techniques and outcomes of surgery for locally advanced renal cell carcinoma with focus on inferior vena cava thrombectomy: the value of a multidisciplinary team

Objective

To report the outcomes of surgery for a contemporary series of patients with locally advanced non-metastatic renal cell carcinoma (RCC) treated at a referral academic centre, focusing on technical nuances and on the value of a multidisciplinary team.

Methods

We queried our prospective institutional database to identify patients undergoing surgical treatment for locally advanced (cT3-T4 N0-1 M0) renal masses suspected of RCC at our centre between January 2017 and December 2020.

Results

Overall, 32 patients were included in the analytic cohort. Of these, 12 (37.5%) tumours were staged as cT3a, 8 (25.0%) as cT3b, 5 (15.6%) as cT3c, and 7 (21.9%) as cT4; 6 (18.8%) patients had preoperative evidence of lymph node involvement. Nine (28.1%) patients underwent nephron-sparing surgery while 23 (71.9%) received radical nephrectomy. A template-based lymphadenectomy was performed in 12 cases, with evidence of disease in 3 (25.0%) at definitive histopathological analysis. Four cases of RCC with level IV inferior vena cava thrombosis were successfully treated using liver transplant techniques without the need for extracorporeal circulation. While intraoperative complications were recorded in 3 (9.4%) patients, no postoperative major complications (Clavien-Dindo ≥3) were observed. At histopathological analysis, 2 (6.2%) patients who underwent partial nephrectomy harboured oncocytoma, while the most common malignant histotype was clear cell RCC (62.5%), with a median Leibovich score of 6 (interquartile range 5–7).

Conclusion

Locally advanced RCC is a complex and heterogenous disease posing several challenges to surgical teams. Our experience confirms that provided careful patient selection, surgery in experienced hands can achieve favourable perioperative, oncological, and functional outcomes.

[Modern tomography imaging techniques in urological diseases]

BACKGROUND

Radiologic imaging is important for the detection, staging and follow-up of urological tumors. Basic therapy decisions for both oncological (surgical vs. systemic therapy, e.g. in testicular cancer) and non-oncological pathologies (interventional vs. conservative therapy, e.g. for ureteral stones) depend largely on the tomographic imaging performed. Due to its almost ubiquitous availability, speed and cost-effectiveness, computed tomography (CT) plays an important role not only in the clarification of abdominal trauma and non-traumatic emergencies, but also in staging and follow-up of oncological patients. However, the level of radiation exposure, impaired renal function and allergies to iodinated contrast media limit the use of CT. Magnetic resonance imaging (MRI) can be a good alternative for many areas of application in oncological and non-oncological imaging due to its high soft tissue differentiation and functional-specific protocols but without the use of ionizing radiation.

AIM

In the following, the main indications of abdominal and pelvic CT and MRI in urology and their limitations are summarized.

RESULTS

The areas of application between CT and MRI are increasingly overlapping, since the latest developments in CT continue to further reduce radiation exposure and increase contrast information, while the speed and robustness of MRI are significantly improving at the same time.

Cross-sectional imaging assessment of renal masses with emphasis on MRI

Magnetic resonance imaging (MRI) is a useful complementary imaging tool for the diagnosis and characterization of renal masses, as it provides both morphologic and functional information. A core MRI protocol for renal imaging should include a T1-weighted sequence with in- and opposed-phase images (or, alternatively with DIXON technique), T2-weighted and diffusion-weighted images as well as a dynamic contrast-enhanced sequence with subtraction images, followed by a delayed post-contrast T1-weighted sequence. The main advantages of MRI over computed tomography include increased sensitivity for contrast enhancement, less sensitivity for detection of calcifications, absence of pseudoenhancement, and lack of radiation exposure. MRI may be applied for renal cystic lesion characterization, differentiation of renal cell carcinoma (RCC) from benign solid renal tumors, RCC histologic grading, staging, post-treatment follow-up, and active surveillance of patients with treated or untreated RCC.

A Plea for Surgery in Pancreatic Metastases from Renal Cell Carcinoma: Indications and Outcome from a Multicenter Surgical Experience

BACKGROUND

Pancreatic metastases from renal-cell carcinoma (RCC-PMs) are rare. Surgery may play a role in improving overall (OS) and disease-free survival (DFS).

METHODS

Clinical-pathological features, surgery and follow-up data of patients with RCC-PMs operated on in three pancreatic surgical centers (2000-2019) were retrospectively evaluated.

RESULTS

Thirty-nine patients (21 male/18 female, averaging 65 years) were enrolled. RCC-PMs were metachronous in 36 patients (mean 94 months, up to 24 years after nephrectomy), multiple in 21 patients, and with a median size of 2.5 (range, 0.7-7.5) cm. All the patients underwent pancreatic surgery (33 standard resections, 6 limited resections). Fifteen patients had post-operative complications (morbidity 38.5%). The median DFS was 63 months, and 19 out of 36 patients showed a disease recurrence. The median OS was 134 months, and 13 out of 36 patients were alive with no evidence of disease. At univariate analysis, lymph node positivity (HR 5.1, 95% CI 1.5-18), multi-visceral resection (HR 3.4, 95% CI 1.1-10) and synchronous RCC-PMs (HR 13, 95% CI 3-55) were significantly associated with a short OS.

CONCLUSION

Surgery may allow a DFS up to 17 years in more than one third of patients, even after limited resections. Splenectomy and lymph node dissection are not mandatory.

The pancreas as a target of metastasis from renal cell carcinoma: Results of surgical treatment in a single institution

Backgrounds/Aims

Metastasis in the pancreatic gland is infrequent, representing between 2-5% of the tumors that affect this organ. However, secondary lesions of clear cell renal carcinoma (CCRC) can occur mainly in this location and it is frequently the only site of dissemination. Treatment of choice is resection in surgically fit patients, as it has been shown that it improves the quality of life and prognosis substantially. We retrospectively reviewed the clinical data of patients with pancreatic resections for metastatic CCRC since there are no reports of the treatment modality of this singular entity in Argentina.

Methods

Retrospective cohort analysis over a 10-year period including eight patients who underwent pancreatic resection for metastatic CCRC.

Results

75% of patients were male with an average age of 65.5 years. The pancreatic surgery occurred at a median time of 9.2 years (1-24.8) from the renal operation. The pancreatic lesions were mostly solitary and asymptomatic. A pancreaticoduodenectomy (PD) was performed in 4 patients (50%). Distal pancreatectomy (DP) was performed in 3 patients (37.3%) and one patient (12.5%) underwent a total pancreaticoduodenectomy. All the patients presented a confirmatory biopsy of pancreatic metastasis of CCRC. Complications were recorded in 3 patients (42.85%). No intraoperative or postoperative mortality was registered. With a median follow-up of 45 months, three patients presented recurrence at 32, 46 and 51 months, respectively. Only one patient showed death due to recurrence at 7.8 month.

Conclusions

CCRC pancreatic metastases treated surgically have a low morbidity and mortality rate in high volume centers, showing excellent long-term survival.

Thoracic Manifestations of Genitourinary Neoplasms and Treatment-related Complications

Genitourinary (GU) malignancies are a diverse group of common and uncommon neoplasms that may be associated with significant mortality. Metastases from GU neoplasms are frequently encountered in the chest, and virtually all thoracic structures can be involved. Although the most common imaging manifestations include hematogenous dissemination manifesting with peripheral predominant bilateral pulmonary nodules and lymphatic metastases manifesting with mediastinal and hilar lymphadenopathy, some GU malignancies exhibit unique features. We review the general patterns, pathways, and thoracic imaging features of renal, adrenal, urothelial, prostatic, and testicular metastatic neoplasms, as well as provide a discussion of treatment-related complications that might manifest in the chest. Detailed reporting of these patterns will allow the imager to assist the referring clinicians and surgeons in accurate determination of the stage, prognosis, and treatment options available for the patient. Awareness of specific treatment-related complications further allows the imager to enhance patient safety through accurate and timely reporting of potentially life-threatening consequences of therapies.

Laparoscopic ultrasonography: The wave of the future in renal cell carcinoma?

Laparoscopic or robotic surgery is the main method of treating renal cell carcinoma (RCC). Laparoscopic surgery can accurately target lesions and shorten patient recovery time. Renal endogenous tumors or inferior vena cava tumor thrombi are very difficult to remove using the laparoscopic approach. The emergence of laparoscopic ultrasonography (LUS) has solved this problem. LUS can assist in the detection of tumor boundaries and the extent of tumor thrombi. The lack of tactile feedback may hinder the development of laparoscopic surgery for the treatment of renal cancer. LUS has become an important tool that has improved the rates of successful surgery. LUS is applied in not only early and locally advanced RCC treatment but also in monitoring ablation therapy, testing renal blood perfusion, and exposing renal pedicles. Sonographic techniques used for LUS include initial B-mode, Doppler, and contrast-enhanced ultrasound (CEUS). Contrast agents applied for CEUS do not induce nephrotoxicity and can display renal perfusion more accurately than the regular color Doppler ultrasound. According to current literature, LUS is a promising technique for the treatment of RCC, especially for endogenous RCC or RCC with thrombosis, and for monitoring the effectiveness of radiofrequency ablation, although further well-designed studies are warranted.

SEOM clinical guideline for treatment of kidney cancer (2017)

The goal of this article is to provide recommendations about the management of kidney cancer. Based on pathologic and molecular features, several kidney cancer variants were described. Nephron-sparing techniques are the gold standard of localized disease. After a randomized trial, sunitinib could be considered in adjuvant treatment in high-risk patients. Patients with advanced disease constitute a heterogeneous population. Prognostic classification should be considered. Both sunitinib and pazopanib are the standard options for first-line systemic therapy in advanced renal cell carcinoma. Based on the results of two randomized trials, both nivolumab and cabozantinib should be considered the standard for second and further lines of therapy. Response evaluation for present therapies is a challenge.

Advances in medical imaging for the diagnosis and management of common genitourinary cancers

Medical imaging of the 3 most common genitourinary (GU) cancers-prostate adenocarcinoma, renal cell carcinoma, and urothelial carcinoma of the bladder-has evolved significantly during the last decades. The most commonly used imaging modalities for the diagnosis, staging, and follow-up of GU cancers are computed tomography, magnetic resonance imaging (MRI), and positron emission tomography (PET). Multiplanar multidetector computed tomography and multiparametric MRI with diffusion-weighted imaging are the main imaging modalities for renal cell carcinoma and urothelial carcinoma, and although multiparametric MRI is rapidly becoming the main imaging tool in the evaluation of prostate adenocarcinoma, biopsy is still required for diagnosis. Functional and molecular imaging using 18-fluorodeoxyglucose-PET and sodium fluoride-PET are essential for the diagnosis, and especially follow-up, of metastatic GU tumors. This review provides an overview of the latest advances in the imaging of these 3 major GU cancers.

Clinical effectiveness of (18)f-fluorodeoxyglucose positron emission tomography/computed tomography in management of renal cell carcinoma: a single institution experience

Positron emission tomography (PET) is currently the most advanced technique of metabolic imaging available for tumor diagnosis and follow-up. The aim of this study was to examine the versatility and accuracy of fluorodeoxyglucose (FDG) PET/computed tomography (CT) in the metastasis detection of renal cell carcinoma (RCC). We also compared our findings to other similar studies from the literature. This is the biggest study so far to examine the sensitivity and specificity of FDG PET/CT in the management of RCC. A retrospective review was carried out on all the FDG PET/CT studies done from January 1999 to January 2014 at our institution. Biopsy results were considered the gold standard. For our patients (n = 315) with biopsy results, FDG PET/CT studies exhibited 100% sensitivity, 100% specificity. Our results were better than results achieved by other studies. The use of FDG PET/CT in restaging and metastasis detection of RCC has many advantages, in addition to high accuracy. This imaging technique has great potential in influencing treatment decisions. We recommend the incorporation of FDG PET/CT in routine standard protocols for RCC.

Nuclear medicine in urological cancers: what is new?

ABSTRACT 

The diffusion of PET/computed tomography has opened up a new role for nuclear imaging in urological oncology. Prostate cancer is evaluated with choline (11C or 18F) PET due to a lack of sensitivity of 18F-fluorodeoxyglucose (FDG). However, many new tracers, such as 18F-fluorocyclobutane-1-carboxylic acid and 68Ga-prostate-specific membrane antigen, are under investigation, offering promising results in the particular setting of radically treated patients with biochemical relapse. The performance of 18F-FDG depends on the histological type; indeed, renal cell cancer may present variable metabolic uptake. In this field, mainly antibodies labeled with positron emitters are under clinical evaluation. Finally, 18F-FDG PET/computed tomography has been proven to show good accuracy in detecting metastatic testicular and bladder cancers, despite not having valid results in detecting local disease. The urological cancer diagnostic process is currently under continuous development.

Different presentations of renal cell cancer on ultrasound and computerized tomography

Renal cell carcinoma (RCC) is the most common malignant tumor of the kidney. The major goal of imaging techniques is to correctly differentiate between benign and malignant renal lesions. We present the cases of six patients with renal masses that were interpreted completely differently based on ultrasound (US) and computerized tomography (CT) findings.From January 1st, 2008 to March 1st, 2014, 307 patients from our center underwent nephrectomy for RCC. In all patients US and CT were performed before the operation.In six patients, the US indicated a focal, solid renal lesion that was interpreted by CT as a cystic lesion (Bosniak II-III). Because discrepancies were evident, renal biopsies were performed. The biopsies revealed RCC in the six patients, all of whom underwent subsequent nephrectomy. All of the patients were confirmed to have macroscopically solid RCC without any cystic components.In most cases, CT is the most accurate diagnostic technique for the clinical diagnostic classification of renal masses. In cases where US characterizes a renal lesion as solid, despite CT findings of a cystic lesion, kidney biopsies are recommended. The 6 cases reported here support our belief that, in diagnostic processes of RCC, these techniques should be complementary used.

[Positron emission tomography/magnetic resonance: Present and future]

PET/MRI has recently been introduced onto the market after several years of research and development. The simple notion of combining the molecular capabilities of the PET and its difference available radiotracers with the excellent tissue resolution of the MRI and wide range of multiparametric imaging techniques has generated great expectations upon the possible uses of this technology. Many challenges must be worked out. However, the most urgent one is the derivation of the MRI-based attenuation correction map. This is especially true because the PET/CT has already demonstrated a huge clinical impact within oncology, neurology and cardiology during its short existence. Despite these difficulties, research is being carried out at a rapid pace in the clinical setting in order to find areas in which the PET/MRI is superior to other existing imaging modalities. In the few initial publications found up to date that have analyzed its clinical role, areas have been identified where PET/CT can migrate to PET/MRI, even if only to suppress the CT scan's ionizing radiation. Nonetheless, there are many theoretical applications in which the PET/MRI can further improve the field of diagnostic imaging. In this article, we will review those applications, the evidence existing regarding the MRI and PET that support those premises as well as that which we have learned in the short period of one year with our experience using the PET/MRI.

Using magnetic resonance imaging and spectroscopy in cancer diagnostics and monitoring: preclinical and clinical approaches

Nuclear Magnetic Resonance (MR) based imaging has become an integrated domain in today's oncology research and clinical management of cancer patients. MR is a unique imaging modality among numerous other imaging modalities by providing access to anatomical, physiological, biochemical and molecular details of tumour with excellent spatial and temporal resolutions. In this review we will cover established and investigational MR imaging (MRI) and MR spectroscopy (MRS) techniques used for cancer imaging and demonstrate wealth of information on tumour biology and clinical applications MR techniques offer for oncology research both in preclinical and clinical settings. Emphasis is given not only to the variety of information which may be obtained but also the complementary nature of the techniques. This ability to determine tumour type, grade, invasiveness, degree of hypoxia, microvacular characteristics, and metabolite phenotype, has already profoundly transformed oncology research and patient management. It is evident from the data reviewed that MR techniques will play a key role in uncovering molecular fingerprints of cancer, developing targeted treatment strategies and assessing responsiveness to treatment for personalized patient management, thereby allowing rapid translation of imaging research conclusions into the benefit of clinical oncology.

Imaging review of skeletal tumors of the pelvis malignant tumors and tumor mimics

Malignant lesions of the pelvis are not uncommon and need to be differentiated from benign lesions and tumor mimics. Appearances are sometimes nonspecific leading to consideration of a broad differential diagnosis. Clinical history, anatomic location, and imaging characterization can help narrow the differential diagnosis. The focus of this paper is to demonstrate the imaging features and the role of plain films, computed tomography, and magnetic resonance imaging for detecting and characterizing malignant osseous pelvic lesions and their common mimics.

Cardiovascular magnetic resonance imaging in assessment of intracaval and intracardiac extension of renal cell carcinoma

OBJECTIVES

About 1 in 5 patients with renal cell carcinoma have intravascular tumoral extension at presentation. Level of tumoral extension within inferior vena cava determines surgical approach, with higher extension requiring cardiopulmonary bypass. Tumoral invasion of inferior vena caval wall is associated with poor prognosis. We evaluated accuracy of magnetic resonance imaging (MRI) in assessing level of intravascular extension of renal cell carcinoma and predicting vessel wall invasion.

METHODS

MRIs and surgical database were reviewed from January 1999 to December 2008. Sixty-four patients with suspected intravascular extension of renal cell carcinoma underwent MRI. Forty-one underwent curative or palliative surgery at our institution and were included in final analysis. MRI scans were reviewed to determine intravascular extension and tumoral adherence to the vessel wall, as assessed by circumferential flow around the intravascular tumor and its mobility during different phases of cardiac cycle. MRI findings were correlated with surgical findings to assess accuracy.

RESULTS

There was 87.8% agreement (P < .001; κ = 0.82) between MRI and surgical findings regarding level of intravascular extension of tumor. MRI was highly sensitive and specific (93%) in assessing supradiaphragmatic extension (negative predictive value, 96%). Depending on sign used, sensitivities and negative predictive values in assessing tumoral adherence to vessel wall ranged from 86% to 95% and 81% to 91%, respectively.

CONCLUSIONS

MRI is highly accurate in staging intravascular and intracardiac extension, aiding in accurate preoperative surgical planning. MRI may help determine prognosis of renal cell carcinoma by accurately assessing tumoral adherence to the vessel wall.

Understanding the Warburg effect and the prognostic value of stromal caveolin-1 as a marker of a lethal tumor microenvironment

Cancer cells show a broad spectrum of bioenergetic states, with some cells using aerobic glycolysis while others rely on oxidative phosphorylation as their main source of energy. In addition, there is mounting evidence that metabolic coupling occurs in aggressive tumors, between epithelial cancer cells and the stromal compartment, and between well-oxygenated and hypoxic compartments. We recently showed that oxidative stress in the tumor stroma, due to aerobic glycolysis and mitochondrial dysfunction, is important for cancer cell mutagenesis and tumor progression. More specifically , increased autophagy/mitophagy in the tumor stroma drives a form of parasitic epithelial-stromal metabolic coupling. These findings explain why it is effective to treat tumors with either inducers or inhibitors of autophagy, as both would disrupt this energetic coupling. We also discuss evidence that glutamine addiction in cancer cells produces ammonia via oxidative mitochondrial metabolism. Ammonia production in cancer cells, in turn, could then help maintain autophagy in the tumor stromal compartment. In this vicious cycle, the initial glutamine provided to cancer cells would be produced by autophagy in the tumor stroma. Thus, we believe that parasitic epithelial-stromal metabolic coupling has important implications for cancer diagnosis and therapy, for example, in designing novel metabolic imaging techniques and establishing new targeted therapies. In direct support of this notion, we identified a loss of stromal caveolin-1 as a marker of oxidative stress, hypoxia, and autophagy in the tumor microenvironment, explaining its powerful predictive value. Loss of stromal caveolin-1 in breast cancers is associated with early tumor recurrence, metastasis, and drug resistance, leading to poor clinical outcome.

Imaging of renal cell carcinoma: state of the art and recent advances

BACKGROUND AND AIM

Renal cell carcinoma (RCC) is the 13th most common cancer worldwide and accounts for 4% of all adult malignancies. Herein the state of the art and recent advances in cross-sectional radiological imaging applied to RCC are reviewed, including ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography.

METHODS

Literature search of peer-reviewed papers published by October 2010.

RESULTS

In front of more conventional and widespread imaging tools, such as ultrasonography and computed tomography, an array of newer and attractive radiological modalities are under investigation and show promise to improve our ability to noninvasively detect renal tumors and its recurrences, accurately assess the extent of the disease, and reliably evaluate treatment response, particularly in the era of antiangiogenetic therapy.

CONCLUSIONS

Recent major advances in radiological imaging techniques have considerably improved our ability to diagnose, stage and follow-up RCC. Further studies are needed to evaluate the potential of most recent and still investigational imaging tools.