Significance of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography for the postoperative surveillance of advanced renal cell carcinoma

Can 18 F FDG PET/CT metabolic parameters be used to noninvasively differentiate between different histopathological subtypes and Fuhrman grades of renal cell cancer?

AIM

To evaluate relationship between metabolic PET metabolic parameters and size of the primary tumor, various histopathological subtypes of renal cell carcinoma (RCC) and Fuhrman grade of the tumors.

MATERIAL AND METHODS

Retrospective analysis of 93 biopsy-proven RCC patients who underwent pretreatment flourine 18 flourodeoxyglucose PET/computed tomography ( 18 F FDG PET/CT) was performed. Quantitative PET parameters, size of the primary tumor, histopathological subtypes and Fuhrman grades of the tumor were extracted. We tried to assess if there was any significant difference in the metabolic patterns of various histopathological subtypes of RCCs, Fuhrman grade of the tumors and size of the primary tumor.

RESULTS

A significant correlation was noted between the size of primary tumor and maximum standardized uptake value (SUV max ), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) ( P  < 0.01, P  < 0.001 and P  < 0.001, respectively). SUV max values correlated significantly with the histopathological subtype ( P  < 0.001). Further sub-analyses was also done by segregating the patients into Low grade (Fuhrman grade 1 and 2) vs. High grade (Fuhrman grade 3 and 4). SUV max , MTV and TLG were significantly different between high grade vs. low grade tumors. ROC analysis yielded cut off values for SUV max , MTV and TLG to differentiate between high grade from low grade tumors.

CONCLUSION

FDG PET/CT with the use of metabolic PET parameters can differentiate between different histopathological subtypes of RCC. Incorporation of metabolic parameters into clinical practice can potentially noninvasively identify patients with low-grade vs. high-grade RCC.

PET/Computed Tomography Transformation of Oncology: Kidney and Urinary Tract Cancers

Renal cell carcinoma (RCC) and urothelial carcinoma (UC) are two of the most common genitourinary malignancies. 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) can play an important role in the evaluation of patients with RCC and UC. In addition to the clinical utility of 18F-FDG PET to evaluate for metastatic RCC or UC, the shift in molecular imaging to focus on specific ligand-receptor interactions should provide novel diagnostic and therapeutic opportunities in genitourinary malignancies. In combination with the rise of artificial intelligence, our ability to derive imaging biomarkers that are associated with treatment selection, response assessment, and overall patient prognostication will only improve.

Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer

ABSTRACT

PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology.

ACR Appropriateness Criteria® Staging of Renal Cell Carcinoma: 2022 Update

Renal cell carcinoma is a complex group of highly heterogenous renal tumors demonstrating variable biological behavior. Pretreatment imaging of renal cell carcinoma involves accurate assessment of the primary tumor, presence of nodal, and distant metastases. CT and MRI are the key imaging modalities used in the staging of renal cell carcinoma. Important imaging features that impact treatment include tumor extension into renal sinus and perinephric fat, involvement of pelvicalyceal system, infiltration into adrenal gland, involvement of renal vein and inferior vena cava, as well as the presence of metastatic adenopathy and distant metastases. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Utility of Fluorine18 Fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography in Metabolic Characterization of Solid Renal Mass Lesion and Localization of Extra Renal Lesions in the Body - A Prospective Study from the Tertiary Care Center in South India

Purpose of the Study

Renal mass lesions in majority of the cases are due to malignant etiology and about one-third of them are reported with metastatic lesions at the time of presentation. Thus proper investigational workup is needed for staging and thereby treatment planning. The current fluorine18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F18-FDG PET/CT) study was designed to characterize renal mass lesions metabolically and identifying other metabolically active lesions in the body suggesting metastatic disease.

Materials and Methods

A total of 24 patients (males - 18 and females - 6) with a mean age of 53.8 ± 12.3 years were recruited in this study for dual time-point PET/CT scan. All patients with renal mass lesions underwent contrast-enhanced CT prior to PET/CT. Metabolic parameters such as maximum standardized uptake value (max.SUV) with a cut off ≥2.5 and retention index (RI) of ≥10% were used to label the lesion as malignant and remaining less than cutoff as benign. The final diagnosis of lesion on imaging was confirmed with a histopathological examination (HPE).

Results

Using max.SUV cut off value, 17/24 renal mass lesions were characterized as malignant and remaining 7/24 renal lesions of benign etiology. PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 80%, 75%, 94.1%, 42.8%, and 79.1%, respectively, by considering HPE as a gold standard. Nine patients were diagnosed with distant site involvement suggestive of metastases.

Conclusion

F18-FDG PET/CT can efficiently characterize solid renal mass lesion as benign and malignant using metabolic parameters such as max.SUV and RI. In addition, whole-body survey identified distant site involvement in 25% of the patients, thus contributing change in management.

PSMA Radioligand Uptake as a Biomarker of Neoangiogenesis in Solid Tumours: Diagnostic or Theragnostic Factor?

Due to its overexpression on the surface of prostate cancer cells, prostate-specific membrane antigen (PSMA) is a relatively novel effective target for molecular imaging and radioligand therapy (RLT) in prostate cancer. Recent studies reported that PSMA is expressed in the neovasculature of various types of cancer and regulates tumour cell invasion as well as tumour angiogenesis. Several authors explored the role of diagnostic and therapeutic PSMA radioligands in various malignancies. In this narrative review, we describe the current status of the literature on PSMA radioligands' application in solid tumours other than prostate cancer to explore their potential role as diagnostic or therapeutic agents, with particular regard to the relevance of PSMA radioligand uptake as neoangiogenetic biomarker. Hence, a comprehensive review of the literature was performed to find relevant articles on the applications of PSMA radioligands in non-prostate solid tumours. Data on the general, methodological and clinical aspects of all included studies were collected. Forty full-text papers were selected for final review, 8 of which explored PSMA radioligand PET/CT performances in gliomas, 3 in salivary gland malignancies, 6 in thyroid cancer, 2 in breast cancer, 16 in renal cell carcinoma and 5 in hepatocellular carcinoma. In the included studies, PSMA radioligand PET showed promising performance in patients with non-prostate solid tumours. Further studies are needed to better define its potential role in oncological patients management, especially in those undergoing antineoangiogenic therapies, and to assess the efficacy of PSMA-RLT in this clinical context.

PET-CT in Clinical Adult Oncology-IV. Gynecologic and Genitourinary Malignancies

Simple Summary

Positron emission tomography (PET), typically combined with computed tomography (CT), has become a critical advanced imaging technique in oncology. With concurrently acquired positron emission tomography and computed tomography (PET-CT), a radioactive molecule (radiotracer) is injected in the bloodstream and localizes to sites of tumor because of specific cellular features of the tumor that accumulate the targeting radiotracer. The CT scan provides information to allow better visualization of radioactivity from deep or dense structures and to provide detailed anatomic information. PET-CT has a variety of applications in oncology, including staging, therapeutic response assessment, restaging and surveillance. This series of six review articles provides an overview of the value, applications, and imaging interpretive strategies for PET-CT in the more common adult malignancies. The fourth report in this series provides a review of PET-CT imaging in gynecologic and genitourinary malignancies.

Abstract

Concurrently acquired positron emission tomography and computed tomography (PET-CT) is an advanced imaging modality with diverse oncologic applications, including staging, therapeutic assessment, restaging and longitudinal surveillance. This series of six review articles focuses on providing practical information to providers and imaging professionals regarding the best use and interpretative strategies of PET-CT for oncologic indications in adult patients. In this fourth article of the series, the more common gynecological and adult genitourinary malignancies encountered in clinical practice are addressed, with an emphasis on Food and Drug Administration (FDA)-approved and clinically available radiopharmaceuticals. The advent of new FDA-approved radiopharmaceuticals for prostate cancer imaging has revolutionized PET-CT imaging in this important disease, and these are addressed in this report. However, [¹⁸F]F-fluoro-2-deoxy-d-glucose (FDG) remains the mainstay for PET-CT imaging of gynecologic and many other genitourinary malignancies. This information will serve as a guide for the appropriate role of PET-CT in the clinical management of gynecologic and genitourinary cancer patients for health care professionals caring for adult cancer patients. It also addresses the nuances and provides guidance in the accurate interpretation of FDG PET-CT in gynecological and genitourinary malignancies for imaging providers, including radiologists, nuclear medicine physicians and their trainees.

Role of PSMA-ligands imaging in Renal Cell Carcinoma management: current status and future perspectives

Background

Renal masses detection is continually increasing worldwide, with Renal Cell Carcinoma (RCC) accounting for approximately 90% of all renal cancers and remaining one of the most aggressive urological malignancies. Despite improvements in cancer management, accurate diagnosis and treatment strategy of RCC by computed tomography (CT) and magnetic resonance imaging (MRI) are still challenging. Prostate-Specific Membrane Antigen (PSMA) is known to be highly expressed on the endothelial cells of the neovasculature of several solid tumors other than prostate cancer, including RCC. In this context, recent preliminary studies reported a promising role for positron emission tomography (PET)/CT with radiolabeled molecules targeting PSMA, in alternative to fluorodeoxyglucose (FDG) in RCC patients.

Purpose

The aim of our review is to provide an updated overview of current evidences and major limitations regarding the use of PSMA PET/CT in RCC.

Methods

A literature search, up to 31 December 2021, was performed using the following electronic databases: PubMed, SCOPUS, Web of Science, and Google Scholar.

Results

The findings of this review suggest that PSMA PET/CT could represent a valid imaging option for diagnosis, staging, and therapy response evaluation in RCC, particularly in clear cell RCC.

Conclusions

Further studies are needed for this “relatively” new imaging modality to consolidate its indications, timing, and practical procedures.

Diagnostic value of 18F-FDG PET/CT versus contrast-enhanced MRI for venous tumour thrombus and venous bland thrombus in renal cell carcinoma

The purpose of this study was to compare the ability of ¹⁸F-FDG PET/CT and contrast-enhanced MRI (CEMRI) to detect and grade venous tumour thrombus (VTT) and venous bland thrombus (VBT) in RCC and assess invasion of the venous wall by VTT. The PET/CT and CEMRI data of 41 patients with RCC were retrieved. The difference in maximum standardized uptake value (SUVmax) between VTT and VBT was analysed. According to their pathological diagnosis, the patients were divided into those with and without venous wall invasion. The PET/CT and CEMRI features, including the SUVmax of the primary lesion and VTT, maximum venous diameter, complete occlusion of the vein by VTT, and VTT morphology, were compared between the two groups. All 41 patients had VTT, and eleven of the 41 patients had VBT. The mean SUVmax of the VTT (6.33 ± 4. 68, n = 41) was significantly higher than that of the VBT (1.37 ± 0.26, n = 11; P < 0.001). Ten of the 11 cases of VBT were correctly diagnosed by ¹⁸F-FDG PET/CT, and all 11 were diagnosed by CEMRI. Both ¹⁸F-FDG PET/CT and CEMRI can effectively detect VTT and distinguish VTT from VBT. ¹⁸F-FDG PET/CT is less effective in grading VTT than CEMRI. Complete venous occlusion by VTT indicates venous wall invasion.

KSNM60 in Clinical Nuclear Oncology

Since the foundation of the Korean Society of Nuclear Medicine in 1961, clinical nuclear oncology has been a major part of clinical nuclear medicine in Korea. There are several important events for the development of clinical nuclear oncology in Korea. First, a scintillating type gamma camera was adopted in 1969, which enabled to perform modern oncological gamma imaging. Second, Tc-99 m generator was imported to Korea since 1979, which promoted the wide clinical use of gamma camera imaging by using various kinds of Tc-99 m labeled radiopharmaceuticals. Third, a gamma camera with single photon emission tomography (SPECT) capability was first installed in 1980, which has been used for various kinds of tumor SPECT imaging. Fourth, in 1994, clinical positron emission tomography (PET) scanner and cyclotron with a production of F-18 fluorodeoxyglucose were first installed in Korea. Fifth, Korean Board of Nuclear Medicine was established in 1995, which contributed in the education and manpower training of dedicated nuclear medicine physicians in Korea. Finally, an integrated PET/CT scanner was first installed in 2002. Since that, PET/CT imaging has been a major imaging tool in clinical nuclear oncology in Korea. In this review, a brief history of clinical nuclear oncology in Korea is described.

PET/CT limitations and pitfalls in urogenital cancers

Hybrid FDG PET/CT plays a vital role in oncologic imaging and has been widely adopted for the staging and restaging of a variety of malignancies. Its diagnostic value in urogenital malignancies is less well-known, not at least because of the variable FDG avidity of these tumor entities, the sites of these tumors, and technical challenges associated with sequential imaging of CT and PET. PET/CT interpretation thus can be especially challenging and is associated with many pitfalls, which can lead to both false-positive and false-negative diagnoses as well as incorrect assessment of metabolic change following therapy. Currently, FDG PET/CT is not the standard of care for the initial diagnosis or staging of early-stage or low-risk urogenital cancers; however, it can help evaluate distant metastatic disease, response to therapy, and disease recurrence in high-risk patients. Knowledge of imaging features of tumor metabolic avidity and pitfalls is essential for accurate interpretation.

Role of F-18 FDG PET/CT in the follow-up of asymptomatic renal cell carcinoma patients for postoperative surveillance: based on conditional survival analysis

PURPOSE

This study investigated the clinical usefulness of F-18 fluorodeoxylucose (FDG) positron emission tomography/computed tomography (PET/CT) for postoperative surveillance in the RCC patients in terms of detectability of recurrence and radiation exposure.

METHODS

Three-hundred-and-forty- three RCC patients who underwent surgery and postoperative surveillance were retrospectively included. Conditional recurrent free survival (CRFS) was investigated and diagnostic performance of conventional imaging (CI) which include abdominopelvic CT or/and chest CT was compared to the FDG PET/CT.

RESULTS

At a median follow-up of 4.3 years (0.5-13.0 years), thirty-nine patients (11.4%) developed recurrence. CRFS of the patients increased over time with greater increment in advanced stage. The sensitivity, specificity, positive-predictive value, negative-predictive value, and accuracy of FDG PET/CT were 92.3%, 97%, 80%, 99.0%, and 96.5% in detecting recurrence, while those values for CI were 89.7%, 97.7%, 83.3%, 98.7%, and 96.8%, respectively. There were no significant differences in these values between FDG PET/CT and CI (McNemar test, p = 0.581). The average radiation dose from FDG PET/CT was around 16.9 ± 3.08 mSv at each follow-up time point. For early stage patients, the average radiation dose from CI was around 26.5 ± 8.57 mSv at each follow-up time point, while this was about 33.0 ± 9.76 mSv for advanced stage patients.

CONCLUSION

FDG PET/CT exhibited good diagnostic performance in asymptomatic RCC patients after surgery, of a level comparable to that of CI, but with a lower radiation dose.

Role of positron emission tomography/computed tomography in the evaluation of renal cell carcinoma

Introduction:

Positron emission tomography (PET) is not a standard recommendation in most of the major guidelines for the evaluation of renal cell carcinoma (RCC). Earlier studies evaluating PET scan in patients with RCC have provided discordant results. However, with the advent of newer hybrid PET/computed tomography (CT) scanning systems, this modality has shown increased efficacy in the evaluation of primary renal masses along with the detection of extrarenal metastases, restaging recurrent RCC, and also in monitoring response to targeted therapy. We performed a systematic review of the existing literature on the role of PET scan in the evaluation of RCC.

Methodology:

We systematically searched the databases of PubMed/Medline, Embase, and Google Scholar to identify studies on the use of PET scan in RCC. Using Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, 94 full-text articles were selected, of which 54 relevant articles were then reviewed, after a consensus by the authors.

Results:

Several studies have shown similar sensitivity and specificity of fluoro-2-deoxy-2-d-glucose-PET (FDG-PET) scan as compared to conventional CT scan for the initial diagnosis of RCC, and an improved sensitivity and specificity for the detection of metastases and recurrences following curative therapy. The PET scan may also play a role in predicting the initial tumor biology and pathology and predicting the prognosis as well as the response to therapy.

Conclusion:

The current guidelines do not recommend PET scan in the staging armamentarium of RCCs. However, FDG-PET scan is as efficacious, if not better than conventional imaging alone, in the evaluation of the primary and metastatic RCC, as well as in evaluating the response to therapy, due to its ability to pick up areas of increased metabolic activity early on. Newer tracers such as ^Ga68 prostate specific membrane antigen-labeled ligands may help in opening up newer avenues of theragnostics.

2-[18F]FDG PET/CT parameters associated with WHO/ISUP grade in clear cell renal cell carcinoma

PURPOSE

To explore the potential parameters from preoperative 2-[¹⁸F]FDG PET/CT that might associate with the World Health Organization/the International Society of Urological Pathology (WHO/ISUP) grade in clear cell renal cell carcinoma (ccRCC).

METHODS

One hundred twenty-five patients with newly diagnosed ccRCC who underwent 2-[¹⁸F]FDG PET/CT prior to surgery or biopsy were retrospectively reviewed. The metabolic parameters and imaging features obtained from 2-[¹⁸F]FDG PET/CT examinations were analyzed in combination with clinical characteristics. Univariate and multivariate logistic regression analyses were performed to identify the predictive factors of WHO/ISUP grade.

RESULTS

Metabolic parameters of primary tumor maximum standardized uptake value (SUVmax), tumor-to-liver SUV ratio (TLR), and tumor-to-kidney SUV ratio (TKR) were significantly different between any two of the four different WHO/ISUP grades, except those between the WHO/ISUP grade 3 and grade 4. The optimal cutoff values to predict high WHO/ISUP grade for SUVmax, TLR, and TKR were 4.15, 1.63, and 1.59, respectively. TLR (AUC: 0.841) was superior to TKR (AUC: 0.810) in distinguishing high and low WHO/ISUP grades (P = 0.0042). In univariate analysis, SUVmax, TLR, TKR, primary tumor size, tumor thrombus, distant metastases, and clinical symptoms could discriminate between the high and low WHO/ISUP grades (P < 0.05). In multivariate analysis, TLR (P < 0.001; OR: 1.732; 95%CI: 1.289-2.328) and tumor thrombus (P < 0.001; OR: 6.199; 95%CI: 2.499-15.375) were significant factors for differentiating WHO/ISUP grades.

CONCLUSION

Elevated TLR (> 1.63) and presence of tumor thrombus from preoperative 2-[¹⁸F]FDG PET/CT can distinguish high WHO/ISUP grade ccRCC effectively. 2-[¹⁸F]FDG PET/CT may be a feasible method for noninvasive assessment of WHO/ISUP grade.

An interdisciplinary consensus on the management of bone metastases from renal cell carcinoma

Bone is a major site of haematogenous tumour cell spread in renal cell carcinoma (RCC), and most patients with RCC will develop painful and functionally disabling bone metastases at advanced disease stages. The prognosis of these patients is generally poor and the treatment is, therefore, aimed at palliation. However, RCC-associated bone metastases can be curable in select patients. Current data support a multimodal management strategy that includes wide resection of lesions, radiotherapy, systemic therapy, and other local treatment options, which can improve quality of life and survival. Nevertheless, the optimal approach for metastatic bone disease in RCC has not yet been defined and practical recommendations are rare. To improve the management and outcomes of patients with RCC and bone metastases, the International Kidney Cancer Coalition and the interdisciplinary working group on renal tumours of the German Cancer Society convened a meeting of experts with a global perspective to perform an unstructured review and elaborate on current treatment strategies on the basis of published data and expertise. The panel formulated recommendations for the diagnosis and treatment of patients with RCC and metastasis to the bone. Furthermore, the experts summarized current challenges and unmet patient needs that should be addressed in the future.

In this Expert Consensus, Grünwald et al. summarize their recommendations for the diagnosis and treatment of patients with renal cell carcinoma and metastasis to the bone. They also outline current challenges and unmet patient needs that should be addressed in the future.

Role of Positron Emission Tomography Imaging in Metabolically Active Renal Cell Carcinoma

PURPOSE OF REVIEW

The clinical role of fluorine-18 fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET) in renal cell carcinoma (RCC) is still evolving. Use of FDG PET in RCC is currently not a standard investigation in the diagnosis and staging of RCC due to its renal excretion. This review focuses on the clinical role and current status of FDG PET and PET/CT in RCC.

RECENT FINDINGS

Studies investigating the role of FDG PET in localized RCC were largely disappointing. Several studies have demonstrated that the use of hybrid imaging PET/CT is feasible in evaluating the extra-renal disease. A current review of the literature determines PET/CT to be a valuable tool both in treatment decision-making and monitoring and in predicting the survival in recurrent and metastatic RCC. PET/CT might be a viable option in the evaluation of RCC, especially recurrent and metastatic disease. PET/CT has also shown to play a role in predicting survival and monitoring therapy response.

Role of contrast-enhanced 18F-FDG PET/CT imaging in the diagnosis and staging of renal tumors

PURPOSE

The objectives of this prospective study are to compare intravenous contrast-enhanced (CE) fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CE F-FDG PET/CT) with conventional methods (CT/MRI) and to evaluate the relationship of maximum standardized uptake value (SUVmax) with Fuhrman grade in patients with renal tumors.

PATIENTS AND METHODS

A total of 62 patients [35 males and 27 females; mean age 55.8±12.7 (range: 27-81) years] were enrolled in the study. CE F-FDG PET/CT scanning included whole-body (early) and abdominal imaging (late) 1 and 2 h after intravenous F-FDG administration, respectively. SUVmax was calculated for primary tumors. CE F-FDG PET/CT and CT/MRI findings were compared with respect to primary tumors and staging.

RESULTS

The sensitivity of CE F-FDG PET/CT in primary tumor detection was 98%, which was very close to that of CT/MRI (100%). CE F-FDG PET/CT resulted in correct staging in 84% of the cases, compared with 68% of the cases with conventional methods (52 vs. 42 patients). SUVmax values of early PET for the primary tumors were significantly correlated with the Fuhrman grades (P<0.001). CE F-FDG PET/CT enabled the detection of synchronous tumors in four patients, one of which was incorrectly diagnosed as having metastasis by CT. Distant metastases were detected in 16 patients with CE F-FDG PET/CT and in 13 patients with routine conventional methods.

CONCLUSION

CE F-FDG PET/CT showed similar results compared with CT/MRI in the detection of primary tumors, but it was superior to conventional methods in the detection of metastasis and staging. Given the highly significant correlation between SUVmax values and the Fuhrman grading, CE F-FDG PET/CT may play a significant role in the evaluation of patient prognosis.

PET-CT and PET-MR in urological cancers other than prostate cancer: An update on state of the art

Hybrid positron emission tomography with computed tomography (PET/CT) and magnetic resonance imaging (PET/MRI) have enabled the combination of morphologic and functional imaging with the promise of providing better information in guiding therapy. Further advance has been made in the past decade with the development of newer radiotracers and optimization of the technical aspects. We performed a search in PubMed, Scopus, and Google Scholar for peer-reviewed literature concerning the advances and newer developments in the imaging of nonprostate urologic cancers between 2005 and 2017. This review aims at summarizing the current evidence on PET imaging in nonprostate urologic cancers and their impact on the diagnosis, staging, prognostication, response assessment, and restaging of these malignancies. However, much of the evidence is still in infancy and has not been incorporated into routine management or the practice guidelines of National Comprehensive Cancer Network or European Society for Medical Oncology (ESMO).

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.

68Ga-DOTATATE Uptake in a Soft Tissue Metastasis From Clear Cell Renal Cell Cancer

A 64-year-old man with a history of metastatic clear cell renal cell cancer was referred for progress Ga-DOTATATE PET/CT imaging. Ga-DOTATATE PET/CT imaging demonstrated increased DOTATATE uptake (SUVmax 13.8) in the left thigh localized to a soft tissue lesion. Cytopathology of the resected lesion was in keeping with a clear cell renal cell cancer metastasis. This case illustrates that Ga-DOTATATE accumulation in a soft tissue lesion can be due to a clear cell renal cell cancer metastasis.

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.

One-month assessment of renal cell carcinoma treated by everolimus using FDG PET/CT predicts progression-free and overall survival

PURPOSE

We evaluated ¹⁸F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) results as outcome predictors for patients with metastatic renal cell carcinoma (RCC) treated by everolimus (EVL), an inhibitor of mammalian target of rapamycin.

METHODS

We retrospectively reviewed 30 patients who were treated with EVL for metastatic RCC between May 2010 and March 2015, by evaluating their FDG PET/CT result before and 1 month after starting EVL treatment. We examined the relationships between each patient's maximum standardized uptake value (max SUVmax) assessed by FDG PET/CT on progression-free survival (PFS) and overall survival (OS).

RESULTS

Median PFS for all 30 patients was 3.77 months (range 0.72-24.56 months) and median OS after EVL treatment of all 30 patients was 11.67 months (range 1.0-62.98 months). Enrolled patients were divided into two groups by max SUVmax prior to EVL (median = 7.6) and at 1 month after EVL treatment (median = 5.7). PFS were significantly shorter in higher max SUVmax prior to EVL (<7.6, PFS 7.8 vs 3.5 months, log-rank P = 0.017) and at 1 month after EVL (<5.7, PFS 10.6 vs 2.7 months, log-rank P = 0.002) than lower max SUVmax. OS were also significantly shorter in higher max SUVmax prior to EVL (<7.6, OS 18.1 vs 7.5 months, log-rank P = 0.010) and at 1 month after EVL (<5.7, OS 17.2 vs 7.5 months, log-rank P = 0.009) than lower max SUVmax. Multivariate Cox hazard regression analysis indicated that max SUVmax at 1 month after EVL is an independent predictor of both PFS and OS in patients treated with EVL although univariate regression analysis showed max SUVmax before EVL is a possible predictor.

CONCLUSIONS

Max SUVmax assessed by FDG PET/CT prior to EVL and at 1 month after EVL treatment can accurately predict PFS and can guide decisions on whether to continue or change treatments for patients with EVL-treated RCC who suffer from adverse events.

The Place of FDG PET/CT in Renal Cell Carcinoma: Value and Limitations

Unlike for most other malignancies, application of FDG PET/CT is limited for renal cell carcinoma (RCC), mainly due to physiological excretion of 18F-fluoro-2-deoxy-2-d-glucose (FDG) from the kidneys, which decreases contrast between renal lesions and normal tissue, and may obscure or mask the lesions of the kidneys. Published clinical observations were discordant regarding the role of FDG PET/CT in diagnosing and staging RCC, and FDG PET/CT is not recommended for this purpose based on current national and international guidelines. However, quantitative FDG PET/CT imaging may facilitate the prediction of the degree of tumor differentiation and allows for prognosis of the disease. FDG PET/CT has potency as an imaging biomarker to provide useful information about patient’s survival. FDG PET/CT can be effectively used for postoperative surveillance and restaging with high sensitivity, specificity, and accuracy, as early diagnosis of recurrent/metastatic disease can drastically affect therapeutic decision and alter outcome of patients. FDG uptake is helpful for differentiating benign or bland emboli from tumor thrombosis in RCC patients. FDG PET/CT also has higher sensitivity and accuracy when compared with bone scan to detect RCC metastasis to the bone. FDG PET/CT can play a strong clinical role in the management of recurrent and metastatic RCC. In monitoring the efficacy of new target therapy such as tyrosine kinase inhibitors (TKIs) treatment for advanced RCC, FDG PET/CT has been increasingly used to assess the therapeutic efficacy, and change in FDG uptake is a strong indicator of biological response to TKI.

Update on advances in molecular PET in urological oncology

Integrated positron emission tomography/computed tomography (PET/CT) with 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) has emerged as a powerful tool for the combined metabolic and anatomic evaluation of many cancers. In urological oncology, however, the use of (18)F-FDG has been limited by a generally low tumor uptake, and physiological excretion of FDG through the urinary system. (18)F-FDG PET/CT is useful when applied to specific indications in selected patients with urological malignancy. New radiotracers and positron emission tomography/magnetic resonance imaging (PET/MRI) are expected to further improve the performance of PET in uro-oncology.

Prognostic Value of Quantitative Metabolic Metrics on Baseline Pre-Sunitinib FDG PET/CT in Advanced Renal Cell Carcinoma

Purpose

The objective of this study was to prospectively evaluate various quantitative metrics on FDG PET/CT for monitoring sunitinib therapy and predicting prognosis in patients with metastatic renal cell cancer (mRCC).

Methods

Seventeen patients (mean age: 59.0 ± 11.6) prospectively underwent a baseline FDG PET/CT and interim PET/CT after 2 cycles (12 weeks) of sunitinib therapy. We measured the highest maximum standardized uptake value (SUVmax) of all identified lesions (highest SUVmax), sum of SUVmax with maximum six lesions (sum of SUVmax), total lesion glycolysis (TLG) and metabolic tumor volume (MTV) from baseline PET/CT and interim PET/CT, and the % decrease in highest SUVmax of lesion (%Δ highest SUVmax), the % decrease in sum of SUVmax, the % decrease in TLG (%ΔTLG) and the % decrease in MTV (%ΔMTV) between baseline and interim PET/CT, and the imaging results were validated by clinical follow-up at 12 months after completion of therapy for progression free survival (PFS).

Results

At 12 month follow-up, 6/17 (35.3%) patients achieved PFS, while 11/17 (64.7%) patients were deemed to have progression of disease or recurrence within the previous 12 months. At baseline, PET/CT demonstrated metabolically active cancer in all cases. Using baseline PET/CT alone, all of the quantitative imaging metrics were predictive of PFS. Using interim PET/CT, the %Δ highest SUVmax, %Δ sum of SUVmax, and %ΔTLG were also predictive of PFS. Otherwise, interim PET/CT showed no significant difference between the two survival groups regardless of the quantitative metric utilized including MTV and TLG.

Conclusions

Quantitative metabolic measurements on baseline PET/CT appears to be predictive of PFS at 12 months post-therapy in patients scheduled to undergo sunitinib therapy for mRCC. Change between baseline and interim PET/CT also appeared to have prognostic value but otherwise interim PET/CT after 12 weeks of sunitinib did not appear to be predictive of PFS.

Diagnostic Challenges of Kidney Cancer: A Systematic Review of the Role of Positron Emission Tomography-Computerized Tomography

PURPOSE

Positron emission tomography-computerized tomography is a leading imaging modality for many types of solid tumors. The ability to characterize molecular processes noninvasively during a relatively fast whole-body scan is the major advantage of this technology. We reviewed the literature in an attempt to clarify the usefulness of positron emission tomography-computerized tomography in patients with a renal mass.

MATERIALS AND METHODS

We searched PubMed® for articles published from 2004 through September 2015 using the keywords "renal," "kidney," "mass," "tumor," "cancer," and "PET/CT."

RESULTS

A total of 158 relevant articles were included in the review. Most diagnostic studies used (18)F-fluorodeoxyglucose, a marker of glucose metabolism, as the radiotracer. The results were substandard, with sensitivity rates in the range of 31.5% to 77% for diagnosis of renal cell carcinomas. There were higher success rates for diagnosis of clear cell carcinomas. Carbonic anhydrase IX is an enzyme expressed in 95% of clear cell carcinomas but not in normal renal tissue or in benign or nonclear cell malignancies. A chimeric mouse-human antibody to carbonic anhydrase IX labeled with (124)I-girentuximab was demonstrated to diagnose clear cell tumors with sensitivity of 86.2% and specificity of 85.9%. For diagnosis of metastases positron emission tomography-computerized tomography with (18)F-fluorodeoxyglucose was observed to be more accurate than computerized tomography alone (94% vs 89%). Studies with other tracers also reveal encouraging results. Positron emission tomography-computerized tomography holds great promise in predicting prognosis and response to tyrosine kinase inhibitors. Current tyrosine kinase inhibitor treatments usually induce only mild lesion shrinkage. Thus, assessment of response based on changes in size of metastases is insufficient. Low (18)F-fluorodeoxyglucose uptake before treatment and decreased uptake after 2 cycles of treatment are associated with better survival. Using labeled medications as radiotracers before actual treatment may assist in selection of the most effective medication for a specific patient.

CONCLUSIONS

Positron emission tomography-computerized tomography with (18)F-fluorodeoxyglucose currently has lower sensitivity compared to enhanced computerized tomography for diagnosis of primary renal masses but better sensitivity for diagnosis of metastases. Predicting and monitoring response to targeted therapy could direct the clinician toward drug selection or modification during therapy. The possibility of treating patients with advanced renal cell carcinoma with (124)I-girentuximab attached to (177)Lu, a strong β-emitter, is investigated.

[Positron-emission tomography in urooncology]

The use of positron emission tomography (PET) is an established method for the diagnosis of urological malignancies. Several tracers are currently available to obtain metabolic information or directly detect molecular targets. While (18)F-FDG-PET is recognized in current guidelines for the staging of seminoma, PET is not used in clinical routine in renal malignancies due to the lack of specific tracers. Despite initial promising results in bladder cancer, no relevant additional diagnostic value with PET using (18)F-FDG or choline-based tracers could be obtained in most patients and therefore should be used with caution or only within clinical trials. In prostate cancer, however, after development of new tracers that, for example, target prostate-specific membrane antigen (PSMA), a paradigm shift in imaging can be recognized. Here, (68)Ga-PSMA-PET might be included in the future as part of standard imaging work-up.

Diagnostic potential of PET/CT using a 68Ga-labelled prostate-specific membrane antigen ligand in whole-body staging of renal cell carcinoma: initial experience

PURPOSE

To evaluate the diagnostic potential of whole-body PET/CT using a ⁶⁸Ga-labelled PSMA ligand in renal cell carcinoma (RCC).

METHODS

Six patients with histopathologically proven RCC underwent ⁶⁸Ga-PSMA PET/CT. Each PET/CT scan was evaluated in relation to lesion count, location and dignity. SUVmax was measured in primary tumours and PET-positive metastases. Tumour-to-background SUVmax ratios (TBR_SUVmax) were calculated for primary RCCs in relation to the surrounding normal renal parenchyma. Metastasis-to-background SUVmax ratios (MBR_SUVmax) were calculated for PET-positive metastases in relation to gluteal muscle.

RESULTS

Five primary RCCs and 16 metastases were evaluated. The mean SUVmax of the primary RCCs was 9.9 ± 9.2 (range 1.7 - 27.2). Due to high uptake in the surrounding renal parenchyma, the mean TBR_SUVmax of the primary RCCs was only 0.2 ± 0.3 (range 0.02 - 0.7). Eight metastases showed focal ⁶⁸Ga-PSMA uptake (SUVmax 9.9 ± 8.3, range 3.4 - 25.6). The mean MBR_SUVmax of these PET-positive metastases was 11.7 ± 0.2 (range 4.4 - 28.1). All PET-negative metastases were subcentimetre lung metastases.

CONCLUSION

⁶⁸Ga-PSMA PET/CT appears to be a promising method for detecting RCC metastases. However, no additional diagnostic value in assessing the primary tumour was found.

Comparison of 11C-4DST and 18F-FDG PET/CT imaging for advanced renal cell carcinoma: preliminary study

PURPOSE

4'-[Methyl-(11)C]-thiothymidine (4DST) has been developed as an in vivo cell proliferation marker based on its DNA incorporation mechanism. This study evaluated the potential of 4DST PET/CT for imaging cellular proliferation in advanced clear cell renal cell carcinoma (RCC), compared with FDG PET/CT. Both 4DST and FDG uptake were compared with biological findings based on surgical pathology.

METHODS

Five patients (3 men and 2 women; mean (±SD) age 64.8 ± 11.0 years) with a single RCC (mean diameter: 9.3 ± 3.2 cm) were examined by PET/CT using 4DST and FDG. The dynamic emission scan of 4DST for RCC over 35 min followed by a static emission scan of the body for 4DST and FDG. Then we compared the maximum standardized uptake value (SUVmax) of 20 areas of RCC on both 4DST and FDG images with (1) the Ki-67 index of cellular proliferation (2) Fuhrman grade system for nuclear grade (G) in RCC and (3) pathological phosphorylated grade of mammalian target of rapamycin (pmTOR).

RESULTS

All patient cases showed clear uptake of FDG and 4DST in RCC tumors, with mean 4DST SUVmax of 7.3 ± 2.2 (range 4.3-9.4) and mean FDG SUVmax of 6.0 ± 2.8 (range 3.4-10.4). The correlation coefficient between SUVmax and Ki-67 index was higher with 4DST (r = 0.61) than with FDG (r = 0.43). Tumor 4DST uptake (G0: 1.4, G2: 2.6, G2 5.6, G4: 5.7) and tumor FDG uptake (G0: 1.8, G2: 2.9, G2 3.7, G4: 4.1) were both related to Fuhrman grade system. The 4DST uptake increased as the pmTOR grade increases (G0: 3.1, G1: 4.8, G2: 4.7, G3: 6.2); in contrast FDG uptake was unrelated to pmTOR grade (G0: 2.8, G2: 4.0, G2 3.3, G4: 3.6).

CONCLUSION

A higher correlation with the proliferation of RCC was observed for 4DST than for FDG. The 4DST uptake exhibits the possibility to predict pmTOR grade, indicating that 4DST has potential for the evaluation of therapeutic effect with mTOR inhibitor in patients with RCC.

FDG PET/CT as a prognostic biomarker in the era of molecular-targeting therapies: max SUVmax predicts survival of patients with advanced renal cell carcinoma

BACKGROUND

Various molecular-targeting therapies have become available for the treatment of advanced renal cell carcinoma (RCC). Accurate prognostication is desirable for choosing the appropriate treatment for individual patients. (18)F-2-fluoro-2-deoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) is a non-invasive tool for evaluating glucose accumulation, which can be an index of biological characteristics of cancer. We prospectively evaluated FDG PET/CT as a prognostic indicator in patients with advanced RCC.

METHODS

A total of 101 patients slated for different systematic therapies for advanced RCC were enrolled between 2008 and 2014. A total of 61 patients had recurrent RCC (58 metastatic and 3 regional) and 40 patients had stage IV RCC (36 metastatic and 4 locoregional). Sixteen patients had not undergone nephrectomy. Pre-treatment FDG PET/CT was performed, and the max SUVmax (the highest SUV measurement in each patient) was recorded. The max SUVmax was compared with different clinical risk factors as prognostic indicators. The median observation period was 18 months (range 1-70 months).

RESULTS

The max SUVmax of the 101 subjects ranged from undetectable to 23.0 (median 6.9). Patients with high max SUVmax had a poor prognosis. Multivariate analysis with standard risk factors revealed that max SUVmax was an independent predictor of survival (p < 0.001; hazard ratio 1.265; 95% confidence interval 1.159-1.380). A cutoff of 8.8 for max SUVmax advocated in our previous report was highly significant (p < 0.0001). When we subclassified the max SUVmax values, the median overall survival of subjects with max SUVmax < 7.0 was 41.9 months. That of subjects with max SUVmax between 7.0 and 12.0 was 20.6 months. That of subjects with max SUVmax ≥ 12.0 was 4.2 months. The differences were statistically significant.

CONCLUSIONS

Pretreatment max SUVmax assessed by FDG PET/CT is a useful prognostic marker for patients with advanced RCC, providing helpful information for clinical decision making.

Renal Cell Carcinoma Metastasis to Ipsilateral Parotid and Submandibular Glands: Report of a Case with Sonoelastographic Findings

Background

Renal cell carcinoma (RCC) – also known as hypernephroma or grawitz tumor – accounts for 3% of the adulthood malignancies. Approximately 30–40% of the patients have metastasis at the time of the diagnosis and most common sites for metastasis are lung, regional lymph nodes, bone and liver. A total of 8–14% of the patients with RCC has head and neck metastasis. However, metastasis to major salivary glands is rarely seen. In this paper, we aimed to report a RCC case with metastasis to parotid and submandibular glands that has the same sonographic and sonoelastographic findings with the primary tumor.

Case Report

66-year old woman with RCC history was referred to our radiology department for neck ultrasound (US) with painful swelling in the right parotid gland region. A well-defined, 37×21 mm sized hypoechoic heterogeneous solid mass was detected in the superficial-deep lobe of the right parotid gland. The mass was prominently hypervascular in color Doppler ultrasonography scan. Coincidentally, a 13×13 mm hypoechoic lobulated solid mass was detected in the right submandibular gland with similar sonographic findings.

Real-time sonoelastography (SEL) was performed to the masses and both of them were blue-green colored that indicates hard tissue. An US and SEL evaluation was also performed to the renal mass (RCC) of the patient. The primary mass was also similar in sonographic and SEL appearance as salivary gland masses. In the patient history, she revealed chemotherapy-radiotherapy treatment 1.5 years ago due to inoperable mass in the mid-lower pole of the left kidney diagnosed as clear cell RCC with vascular invasion, liver, lung and brain metastasis. Because of known primary tumor, the masses in the salivary glands were suspected to be metastatic and a tru-cut biopsy was performed. Pathological result was reported as clear cell RCC metastasis.

Conclusions

The etiology of RCC is still unknown and metastatic involvement can be seen at unexpected tissue and organs. Metastatic disease should be considered when a salivary gland mass detected in patients with RCC history. SEL examination would be helpful in differentiation of the origin of the metastatic lesion with known SEL features.

Staging, surveillance, and evaluation of response to therapy in renal cell carcinoma: role of MDCT

Renal cell carcinoma is the most common malignant renal tumor in the adults. Significant advances have been made in the management of localized and advanced renal cell carcinoma. Surgery is the standard of care and accurate pre-operative staging based on imaging is critical in guiding appropriate patient management. Besides staging, imaging plays a key role in the post-operative surveillance and evaluation of response to systemic therapies. Both CT and MR are useful in the staging and follow up of renal cell carcinoma, but CT is more commonly used due to its lower costs and wider availability. In this article, we discuss and illustrate the role of multi-detector CT in pre-operative staging, post-operative surveillance, and evaluation of response to systemic therapy in renal cell carcinoma.

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.

Management of urological malignancies: Has positron emission tomography/computed tomography made a difference?

Positron emission tomography/computed tomography (PET/CT) technology has been a significant, but expensive addition to the oncologist's armamentarium. The aim of this review was to determine the clinical utility of PET/CT in urological oncology, its impact on disease outcome and cost-effectiveness. We searched MedLine and peer reviewed journals for all relevant literature available online from the year 2000 until January 2014 regarding the use of PET/CT in the management of urological malignancies. (11)C-choline PET/CT has emerged as a powerful tool for assessment of biochemical relapse in prostate cancer. Use of novel radiotracers like (124)I-girentuximab has shown promise in the diagnosis of clear cell renal carcinoma. Fluorodeoxyglucose PET has a proven role in seminoma for the evaluation of postchemotherapy residual masses and has shown encouraging results when used for detection of metastasis in renal, bladder, and penile cancer. Introduction of novel radiotracers and advanced technology has led to a wider application of PET/CT in urological oncology. However, testicular seminoma aside, its impact on disease outcome and cost-effectiveness still needs to be established.

EAU guidelines on renal cell carcinoma: 2014 update

CONTEXT

The European Association of Urology Guideline Panel for Renal Cell Carcinoma (RCC) has prepared evidence-based guidelines and recommendations for RCC management.

OBJECTIVES

To provide an update of the 2010 RCC guideline based on a standardised methodology that is robust, transparent, reproducible, and reliable.

EVIDENCE ACQUISITION

For the 2014 update, the panel prioritised the following topics: percutaneous biopsy of renal masses, treatment of localised RCC (including surgical and nonsurgical management), lymph node dissection, management of venous thrombus, systemic therapy, and local treatment of metastases, for which evidence synthesis was undertaken based on systematic reviews adhering to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Relevant databases (Medline, Cochrane Library, trial registries, conference proceedings) were searched (January 2000 to November 2013) including randomised controlled trials (RCTs) and retrospective or controlled studies with a comparator arm. Risk of bias (RoB) assessment and qualitative and quantitative synthesis of the evidence were performed. The remaining sections of the document were updated following a structured literature assessment.

EVIDENCE SYNTHESIS

All chapters of the RCC guideline were updated. For the various systematic reviews, the search identified a total of 10,862 articles. A total of 151 studies reporting on 78,792 patients were eligible for inclusion; where applicable, data from RCTs were included and meta-analyses were performed. For RCTs, there was low RoB across studies; however, clinical and methodological heterogeneity prevented data pooling for most studies. The majority of studies included were retrospective with matched or unmatched cohorts based on single or multi-institutional data or national registries. The exception was for systemic treatment of metastatic RCC, in which several RCTs have been performed, resulting in recommendations based on higher levels of evidence.

CONCLUSIONS

The 2014 guideline has been updated by a multidisciplinary panel using the highest methodological standards, and provides the best and most reliable contemporary evidence base for RCC management.

PATIENT SUMMARY

The European Association of Urology Guideline Panel for Renal Cell Carcinoma has thoroughly evaluated available research data on kidney cancer to establish international standards for the care of kidney cancer patients.