Increased incidental detection and reduced mortality in renal cancer--recent retrospective analysis at eight institutions

[Renal Biopsy]

The extent of renal biopsy indication is being widened because of the increasing incidence of incidental renal masses; the increasing treatment options for renal cell carcinoma, including ablation therapy and novel targeted treatment; and the increasing incidence of kidney transplantation. However, percutaneous renal biopsy is technically difficult, particularly for beginners, because the skin-to-organ distance is relatively longer than those associated with other organs. In the present review, we will discuss the indications, technical considerations, efficacy, and complications of renal biopsy. Furthermore, we share practical tips of renal biopsy through many examples to help radiologists perform renal biopsy safely and effectively in various situations.

Stereotactic Body Radiotherapy for Localized Kidney Cancer

PURPOSE OF REVIEW

Stereotactic body radiation therapy (SBRT) is increasingly utilized in the management of localized kidney cancers, particularly for patients who are not surgical candidates. Herein, we provide a narrative review of SBRT in the management of localized kidney cancers.

RECENT FINDINGS

Recent prospective studies and multi-institutional retrospective studies highlight the safety and efficacy of SBRT in the management of renal tumors, a disease previously thought to be radioresistant. Studies have shown that local control is greater than 90% with rare grade 3 or 4 toxicity and no grade 5 toxicity. SBRT can be utilized successfully in the treatment of large kidney tumors (> 5 cm). New techniques such as MRI-guided radiation therapy may further improve the therapeutic ratio. However, randomized clinical trials are necessary to confirm the optimal dosing schedule and compare outcomes with nephrectomy, which remains the standard of care in suitable patients. Advances in SBRT have made this modality a safe and effective treatment option in the management of localized kidney cancers.

Incidence trends and survival prediction of urothelial cancer of the bladder: a population-based study

Background

The aim of this study is to determine the incidence trends of urothelial cancer of the bladder (UCB) and to develop a nomogram for predicting the cancer-specific survival (CSS) of postsurgery UCB at a population-based level based on the SEER database.

Methods

The age-adjusted incidence of UCB diagnosed from 1975 to 2016 was extracted, and its annual percentage change was calculated and joinpoint regression analysis was performed. A nomogram was constructed for predicting the CSS in individual cases based on independent predictors. The predictive performance of the nomogram was evaluated using the consistency index (C-index), net reclassification index (NRI), integrated discrimination improvement (IDI), a calibration plot and the receiver operating characteristics (ROC) curve.

Results

The incidence of UCB showed a trend of first increasing and then decreasing from 1975 to 2016. However, the overall incidence increased over that time period. The age at diagnosis, ethnic group, insurance status, marital status, differentiated grade, AJCC stage, regional lymph nodes removed status, chemotherapy status, and tumor size were independent prognostic factors for postsurgery UCB. The nomogram constructed based on these independent factors performed well, with a C-index of 0.823 and a close fit to the calibration curve. Its prediction ability for CSS of postsurgery UCB is better than that of the existing AJCC system, with NRI and IDI values greater than 0 and ROC curves exhibiting good performance for 3, 5, and 8 years of follow-up.

Conclusions

The nomogram constructed in this study might be suitable for clinical use in improving the clinical predictive accuracy of the long-term survival for postsurgery UCB.

Percutaneous cryoablation vs. open partial nephrectomy in small kidney cancers: the Italian experience

INTRODUCTION

The aim of the present work was to analyze the economic impact of PCA (percutaneous cryoablation) vs. OPN (open partial nephrectomy), as it represents the most common standard of care for SRMs (small renal masses), namely T1a renal cancers (<4 cm), in Italy.

EVIDENCE ACQUISITION

A cost analysis was performed to compare the difference of the total perioperative costs between PCA and OPN, both from the perspective of the National Healthcare System and the hospital. Clinical and resources consumption inputs were retrieved by a non-systematic literature search on scientific databases, complemented by a grey literature research, and validated by expert opinion. Costs calculation for the NHS perspective were based on reference tariffs published by the National Ministry of Health, while for the hospital perspective, unit costs published in the grey literature were used to compare the two alternatives.

EVIDENCE SYNTHESIS

Assuming the NHS perspective, the cost analysis shows there is an economic advantage in using PCA vs. OPN (€4080 vs. €7541) for the treatment of SRMs. Hospitalization time is the driver of the total costs, while the costs of complications are quite negligible in both groups. From the hospital perspective the costs of PCA is slightly higher (+€737) than OPN, with cryoprobes contributing as the greatest cost component. However, this increase is quite restrained and is offset by an inferior use of healthcare resources (surgery room, healthcare personnel, length of stay in the hospital).

CONCLUSIONS

According to our analysis, PCA results an advantageous technique compared to OPN respectively in terms of costs and resource consumption from both the NHS and the hospital perspective.

Percutaneous image-guided renal ablations: Current evidences for long-term oncologic efficacy

The rise in incidentally discovered small renal neoplasms has focused attention on nephron-sparing treatment strategies including partial nephrectomy and percutaneous ablation as well as active surveillance. As all treatment modality, renal ablation has matured technically. Radiofrequency ablation, microwave ablation or cryoablation are now performed in many institutions under imaging guidance. The long-term results allow them to be now recommended as a therapeutic option whatever the patients' condition if complete ablation can reliably be achieved.

Protocol for a feasibility study of a cohort embedded randomised controlled trial comparing phron paring reatment (NEST) for small renal masses

INTRODUCTION

Small renal masses (SRMs; ≤4 cm) account for two-thirds of new diagnoses of kidney cancer, the majority of which are incidental findings. The natural history of the SRM seems largely indolent. There is an increasing concern regarding surgical overtreatment and the associated health burden in terms of morbidity and economy. Observational data support the safety and efficacy of percutaneous cryoablation but there is an unmet need for high-quality evidence on non-surgical management options and a head-to-head comparison with standard of care is lacking. Historical interventional trial recruitment difficulties demand novel study conduct approaches. We aim to assess if a novel trial design, the cohort embedded randomised controlled trial (RCT), will enable carrying out such a comparison.

METHODS AND ANALYSIS

Single-centre prospective cohort study of adults diagnosed with SRM (n=200) with an open label embedded interventional RCT comparing nephron sparing interventions. Cohort participants will be managed at patient and clinicians' discretion and agree with longitudinal clinical data and biological sample collection, with invitation for trial interventions and participation in comparator control groups. Cohort participants with biopsy-proven renal cell carcinoma eligible for both percutaneous cryoablation and partial nephrectomy will be randomly selected (1:1) and invited to consider percutaneous cryoablation (n=25). The comparator group will be robotic partial nephrectomy (n=25). The primary outcome of this feasibility study is participant recruitment. Qualitative research techniques will assess barriers and recruitment improvement opportunities. Secondary outcomes are participant trial retention, health-related quality of life, treatment complications, blood transfusion rate, intensive care unit admission and renal replacement requirement rates, length of hospital stay, time to return to pre-treatment activities, number of work days lost, and health technologies costs.

ETHICS AND DISSEMINATION

Ethical approval has been granted (UK HRA REC 19/EM/0004). Study outputs will be presented and published.

TRIAL REGISTRATION

ISRCTN18156881; Pre-results.

Diagnostic value of imprint cytology testing in kidney tumors: review of 200 cases

INTRODUCTION

Previous investigations have studied the importance of imprint cytology (IC) testing of core needle biopsy (CNB) from various organs. We have presented the largest series, to the best of our knowledge, of IC testing of CNB for patients with kidney tumors.

MATERIALS AND METHODS

The present retrospective study (January 1, 2015, through January 30, 2016) identified laboratory information through a computer search of the cytology archived reports for 200 consecutive IC testing with CNB for renal tumors cases. A board-certified cytopathologist and cytology-trained fellow reviewed the IC testing and CNB slides and rendered them as nondiagnostic, positive for malignancy, negative for malignancy, positive for neoplasm, or atypical. The tumors were graded using the International Society of Urological Pathology grading system. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated.

RESULTS

The IC testing cases classified as atypical (n = 53) or positive for neoplasm (n = 28) were evaluated separately because of the ambiguous morphologic characteristics. Of the other 119 cases, IC testing classified 95 (80%) as positive for malignancy, 5 (4%) as negative for malignancy, and 19 (16%) as nondiagnostic. The corresponding CNB histologic diagnoses showed that 85 of 95 cases (89%) were true positive for malignancy. Of these 85 cases, 45 (53%) were low grade, 21 (25%) were high grade, and 19 (22%) were ungraded. The corresponding sensitivity, specificity, and accuracy were 85%, 11%, and 58%, respectively. The 53 IC-identified atypical cases were more likely to be malignant (n = 40; 75%). Of the remaining IC testing atypical cases, 12 (23%) were negative for malignancy and 1 (2%) was nondiagnostic. Of the 28 cases positive for neoplasm using IC, 13 (46%) were positive and 15 (54%) were negative for malignancy.

CONCLUSIONS

The relatively low diagnostic value of IC testing for renal tumors showed it to be less powerful for screening than its use in other organs.

Trends in the incidence and mortality of transitional cell carcinoma of the bladder for the last four decades in the USA: a SEER-based analysis

BACKGROUND

Transitional cell carcinoma (TCC) accounts for around 95% of bladder cancers and is the 4th most common cancer among men and the tenth most common in women, in the US. There is a constant need to clarify current TCC incidence and mortality rates among different population groups for better clinical practice guidelines. We aimed to describe the TCC incidence and incidence-based mortality by demographic and tumor-related characteristics over the last 40 years in the US.

METHODS

We obtained data from the SEER 18 registries to study TCC cases that were diagnosed between the years 1973 and 2014. We calculated incidence rates and incidence-based mortality rates in different demographic and tumor-related characteristics and expressed rates by 100,000 person-years. We then calculated the annual changes in incidence and incidence-based mortality rates and displayed them as annual percent changes (APCs).

RESULTS

There were 182,114 patients with TCC between 1973 and 2014 in the United States. Overall incidence rates of TCC increased 0.16% (95% CI, 0.02-0.30, p = .02) per year over the study period. However, the incidence declined significantly since 2007; (95%CI,-1.89- -0.77, p < .001), except among the elderly and African Americans, which increased significantly over the study period. Overall TCC mortality rates did not change over the study period. However, since 2000 it started to decrease significantly.

CONCLUSION

TCC incidence and incidence-based mortality rates had been showing significant increases over the previous decades. However, significant declines in both incidence and incidence-based mortality rates have been observed over the recent years, except in some patients with certain racial groups. Improved understanding of the etiological and ecological factors of TCC could lead to further declines in incidence and incidence-based mortality rates.

Cryosurgical Ablation of Renal Cell Carcinoma

BACKGROUND

Small renal masses are being commonly diagnosed incidentally in older patients. A partial nephrectomy is the first-line nephron sparing treatment option for these lesions. However, probe ablative therapy such as cryoablation is emerging as an alternative option for select patients requiring nephron sparing surgery.

METHODS

The current literature regarding the management of small renal lesions with cryoablation was retrospectively reviewed. We selected six of the largest published series of renal cryoablation with a total of 320 patients. The diagnosis, staging, treatment options, mechanism, efficacy and morbidity associated with renal cryoablation were evaluated.

RESULTS

Renal cryoablation for localized small renal masses is well tolerated and associated with a low complication rate. The range of mean tumor size in our literature review series (320 patients) was 2.3 to 2.6 cm. After a range of mean follow-up of 5.9 to 72 months, including a series with a minimum of 5 years of follow-up, the cancer specific survival was 97% to 100% and overall patient survival was 82% to 90.2%.

CONCLUSIONS

Renal cryoablation, based on available clinical reports, appears to be a curative option for patients with small localized renal cell carcinomas (RCCs) who are unwilling or unable to undergo a partial nephrectomy. With encouraging intermediate oncological follow-up available, longer-term follow-up is needed to validate the use of cryoablation as a primary treatment option.

Aorta-Lesion-Attenuation-Difference (ALAD) on contrast-enhanced CT: a potential imaging biomarker for differentiating malignant from benign oncocytic neoplasms

OBJECTIVE

To evaluate whether the Aorta-Lesion-Attenuation-Difference on contrast-enhanced CT can aid in the differentiation of malignant and benign oncocytic renal neoplasms.

MATERIALS AND METHODS

Two independent cohorts-an initial (biopsy) dataset and a validation (surgical) dataset-with oncocytomas and chromophobe renal cell carcinomas (chRCC) were included in this IRB-approved retrospective study. A region of interest was placed on the renal mass and abdominal aorta on the same CT image slice to calculate an Aorta-Lesion-Attenuation-Difference (ALAD). ROC curves were plotted for different enhancement phases, and diagnostic performance of ALAD for differentiating chRCC from oncocytomas was calculated.

RESULTS

Seventy-nine renal masses (56 oncocytomas, 23 chRCC) were analyzed in the initial (biopsy) dataset. Thirty-six renal masses (16 oncocytomas, 20 chRCC) were reviewed in the validation (surgical) cohort. ALAD showed a statistically significant difference between oncocytomas and chromophobes during the nephrographic phase (p < 0.001), early excretory phase (p < 0.001), and excretory phase (p = 0.029). The area under the ROC curve for the nephrographic phase was 1.00 (95% CI: 1.00-1.00) for the biopsy dataset and showed the narrowest confidence interval. At a threshold value of 25.5 HU, sensitivity was 100 (82.2%-100%) and specificity was 81.5 (61.9%-93.7%). When tested on the validation dataset on measurements made by an independent reader, the AUROC was 0.93 (95% CI: 0.84-1.00) with a sensitivity of 100 (80.0%-100%) and a specificity of 87.5 (60.4%-97.8%).

CONCLUSIONS

Nephrographic phase ALAD has potential to differentiate benign and malignant oncocytic renal neoplasms on contrast-enhanced CT if histologic evaluation on biopsy is indeterminate.

Comparison of the Clinical Efficacy of Retroperitoneal Laparoscopic Partial Nephrectomy and Radical Nephrectomy for Treating Small Renal Cell Carcinoma: Case Report and Literature Review

Background

Renal cell carcinoma (RCC) is a common malignancy of the urinary system with high rates of morbidity and mortality.

Objectives

This study aimed to investigate and analyze the clinical efficacy of retroperitoneal laparoscopic partial nephrectomy and laparoscopic radical nephrectomy for the treatment of small RCC.

Methods

In this retrospective study of 45 patients with small RCC, the patients were divided into two treatment groups: Group A (retroperitoneal laparoscopic partial nephrectomy, 25 cases) and Group B (retroperitoneal laparoscopic radical nephrectomy, 20 cases).

Results

There were no statistically significant differences in the operative time, amount of intraoperative blood loss, length of hospital stay, preoperative creatinine level, postoperative creatinine level after 24 hours, and survival rate after 1, 2, and 3 years between the two groups (P > 0.05).

Conclusions

There were no significant differences in the survival rates and short-term postoperative complications between the laparoscopic partial nephrectomy group and the laparoscopic radical nephrectomy group for small RCC, but the former was slightly more effective.

Microwave ablation of renal tumors: A narrative review of technical considerations and clinical results

PURPOSE

The purpose of this review was to identify the specific technical considerations to adequately perform microwave ablations (MWA) of renal tumors and analyze the currently available clinical results.

METHODS

Using Medline, a systematic review was performed including articles published between January 2000 and September 2016. English language original articles, reviews and editorials were selected based on their clinical relevance.

RESULTS

MWA has several theoretical advantages over radiofrequency ablation in consistently providing higher intratumoral temperatures. MWA is less dependent of electrical conductivities of tissues and the delivered energy is less limited by desiccation of heated tissues. While there are insufficient data, especially because of a lack of studies with mid- to long-term follow-up, to determine the oncologic effectiveness of MWA, this technique appears safe and effective for the ablation of T1 renal tumors. There is evidence for using mid-level settings based on experimental and clinical data. Power set at 50-65W for 5-15min appears adequate in kidney but close clinical and imaging follow-up have to be performed.

CONCLUSION

Renal MWA offers theoretical advantages by comparison with other available techniques to treat renal tumors. However, MWA suffers of less cumulative data compared to radiofrequency ablation or cryoablation. Moreover, microwaves still require further studies to identify the optimal tumor characteristics and device settings leading to predictable ablation.

Epidemiology of Renal Cell Carcinoma

The increasing incidence of RCC in most populations may in part be due to increasing numbers of incidentally detected cancers with new imaging methods. Further, the increase is not only limited to small local tumours but also includes more advanced tumours, which may to some part explain the still high mortality rates. The variation in incidence between populations may have several other explanations. Traditionally the starting point has included thoughts of environmental exposures, which so far have only in part explained the causes of RCC, by means of cigarette smoking and obesity, which may account for approximately 40% of cases in high-risk countries (Table 2). Further, the genetic variations may be of importance as a cause of the difference between populations. Continued research in RCC is needed with the knowledge that nearly 50% of patients die within 5 years after diagnosis. The further search for environmental exposures should take in account the knowledge that RCC consists of different types with specific genetic molecular characteristics. These genetic alterations have in some cases been suggested to be associated with specific exposures. Furthermore, there might exist a modulating effect of genetic polymorphisms among metabolic activation and detoxification enzymes. Hence, a further understanding of the genetic and molecular processes involved in RCC will hopefully give us a better knowledge how to analyse and interpret exposure associations that have importance for both initiation and progression of RCC.

Percutaneous Cryoablation for Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults. Nephron sparing resection (partial nephrectomy) has been the “gold standard” for the treatment of resectable disease. With the widespread use of cross sectional imaging techniques, more cases of renal cell cancers are detected at an early stage, i.e. stage 1A or 1B. This has provided an impetus for expanding the nephron sparing options and especially, percutaneous ablative techniques. Percutaneous ablation for RCC is now performed as a standard therapeutic nephron-sparing option in patients who are poor candidates for resection or when there is a need to preserve renal function due to comorbid conditions, multiple renal cell carcinomas, and/or heritable renal cancer syndromes. During the last few years, percutaneous cryoablation has been gaining acceptance as a curative treatment option for small renal cancers. Clinical studies to date indicate that cryoablation is a safe and effective therapeutic method with acceptable short and long term outcomes and with a low risk, in the appropriate setting. In addition it seems to offer some advantages over radio frequency ablation (RFA) and other thermal ablation techniques for renal masses.

Computer-aided detection of exophytic renal lesions on non-contrast CT images

Renal lesions are important extracolonic findings on computed tomographic colonography (CTC). They are difficult to detect on non-contrast CTC images due to low image contrast with surrounding objects. In this paper, we developed a novel computer-aided diagnosis system to detect a subset of renal lesions, exophytic lesions, by (1) exploiting efficient belief propagation to segment kidneys, (2) establishing an intrinsic manifold diffusion on kidney surface, (3) searching for potential lesion-caused protrusions with local maximum diffusion response, and (4) exploring novel shape descriptors, including multi-scale diffusion response, with machine learning to classify exophytic renal lesions. Experimental results on the validation dataset with 167 patients revealed that manifold diffusion significantly outperformed conventional shape features (p<1e-3) and resulted in 95% sensitivity with 15 false positives per patient for detecting exophytic renal lesions. Fivefold cross-validation also demonstrated that our method could stably detect exophytic renal lesions. These encouraging results demonstrated that manifold diffusion is a key means to enable accurate computer-aided diagnosis of renal lesions.

Associations between presenting symptoms, clinicopathological parameters, and prognosis in a contemporary series of patients with renal cell carcinoma

Purpose

To evaluate the impact of presenting symptoms on survival in a contemporary series of patients with renal cell carcinoma (RCC).

Materials and Methods

We prospectively recorded data on the presenting symptoms, pathology, and RCC-specific survival of 633 consecutive RCC patients who underwent surgery between 2003 and 2012.

Results

Four hundred thirty-three RCCs (68%) were incidental, 111 (18%) were associated with local symptoms, and 89 (14%) were associated with systemic symptoms. Among those with incidental RCC, 317 patients (73%) were completely asymptomatic and 116 patients (27%) presented with symptoms not related to the tumor. During a median follow-up interval of 40 months (interquartile range: 39 to 69 months), 77 patients died from RCC. In univariate analyses, symptom classification was significantly associated with RCC-specific survival (p<0.001). Patients with incidental RCC and unrelated symptoms tended to have worse prognosis than did patients who were completely asymptomatic, although this difference was not statistically significant (p=0.057). The symptom classification was associated with advanced TNM stages (p<0.001) and grade (p<0.001).

Conclusions

This study confirms that presenting symptoms are associated with tumor characteristics and survival. The majority of RCCs are diagnosed incidentally in patients without any symptoms or with symptoms not related to RCC. Patients in the latter group tend to have a worse prognosis than do patients who are completely asymptomatic. With the increasing number of incidentally diagnosed RCCs, substratification of patients with incidental tumors may be prognostically relevant.

Renal ablation update

Thermal ablative technologies have evolved considerably in the recent past and are now an important component of current clinical guidelines for the treatment of small renal masses. Both radiofrequency ablation and cryoablation have intermediate-term oncologic control that rivals surgical options, with favorable complication profiles. Studies comparing cryoablation and radiofrequency ablation show no significant difference in oncologic control or complication profile between the two modalities. Early data from small series with microwave ablation have shown similar promising results. Newer technologies including irreversible electroporation and high-intensity-focused ultrasound have theoretical advantages, but will require further research before becoming a routine part of the ablation armamentarium. The purpose of this review article is to discuss the current ablative technologies available, briefly review their mechanisms of action, discuss technical aspects of each, and provide current data supporting their use.

MR-guided laser-induced thermotherapy in ex vivo porcine kidney: comparison of four different imaging sequences

PURPOSE

To evaluate the clinical value of different magnetic resonance imaging (MRI) sequences for a real-time thermo-monitoring during laser-induced thermotherapy (LITT) in kidneys.

METHODS

Twenty-eight ex vivo pig kidneys were treated with laser ablation under MR guidance in a high-field MR scanner (Magnetom Espree or Avanto Fit, Siemens, Germany). For the thermal ablation of the kidney, a neodymium yttrium-aluminum-garnet (Nd:YAG) laser was used in combination with a special protective catheter (length 43 cm, 4 French) which is sealed at the distal end. First, ablation was performed for 7, 10, and 13 minutes using FLASH sequences for investigation of time-dependent growth of lesion size. In the second step, we evaluated the optimal imaging sequence during a 7 minutes ablation of the kidney and after cooling using four different MR sequences (Haste, FLASH, radial VIBE, and Caipirinha DIXON).

RESULTS

Macroscopic lesion volume increased from 3,784 ± 1,525 mm(3) to 7,683 ± 5,756 mm(3) after the ablation from 7 to 13 minutes and MR volume ranged from 2,107 ± 1,674 mm(3) to 2,934 ± 1,549 mm(3) after the ablation from 7 to 13 minutes. During ablation, FLASH (132 ± 34%) and radial VIBE (120 ± 43%) sequences displayed lesion volumes most efficiently with a trend to overestimation. The Caipirinha DIXON (323 ± 24%) sequence overestimated the volumes significantly during real-time monitoring. The volumes measured by MRI with FLASH (61 ± 30%), Haste (67 ± 28%), or radial VIBE (48 ± 14%) sequences after cooling of the kidney after ablation were always underestimated. The Caipirinha DIXON (142 ± 2%) sequence still overestimated the lesion volume after cooling of the kidney.

CONCLUSION

LITT is a feasible ablation modality in kidney tissue. Moreover, macroscopic and MR lesion volume increases time-dependently. For online monitoring, radial VIBE and FLASH sequences seem to be most efficient.

Ten-year experience of percutaneous image-guided radiofrequency ablation of malignant renal tumours in high-risk patients

OBJECTIVES

To evaluate survival and outcomes after percutaneous radiofrequency ablation (RFA) of malignant renal tumours in high-risk patients with long-term follow-up.

METHODS

Between 2002 and 2009, 62 patients (71 tumours), with a median age of 73.5 years (20-87), consecutively treated with RFA under ultrasound or computed tomography guidance for malignant renal tumours were retrospectively selected and prospectively followed until 2012, including 25 patients (40.3 %) with solitary kidney and 7 cystic cancers. Maximal tumour diameters were between 8 and 46 mm (median: 23 mm).

RESULTS

Radiofrequency ablation was technically possible for all patients. Mean follow-up was 38.8 months (range: 18-78 months). Primary and secondary technique effectiveness was 95.2 % and 98.4 % per patient respectively. The rates of local tumour progression and metastatic evolution were 3.2 % and 9.7 % per patient and were associated with tumour size >4 cm (P = 0.005). The disease-free survival rates were 88.3 % and 61.9 % at 3 and 5 years. No significant difference in glomerular filtration rates before and after the procedure was observed (P = 0.107). The major complications rate was 5.9 % per session with an increased risk in the case of central locations (P = 0.006).

CONCLUSIONS

Percutaneous renal RFA appears to be safe and effective with useful nephron-sparing results.

KEY POINTS

• Radiofrequency ablation (RFA) is a well-tolerated technique according to mid-term results. • RFA for malignant renal tumours preserved renal function in high-risk patients. • Mid-term efficacy of RFA was close to that of formal conservative surgery. • Tumour size and central location limit the efficacy and safety of RFA.

Renal function outcomes for multifocal renal neoplasms managed by radiofrequency ablation

PURPOSE

To evaluate renal function changes related to radiofrequency ablation (RFA) for the treatment of multifocal renal neoplasms.

METHODS

This is an institutional review board-approved, Health Insurance Portability and Accountability Act compliant retrospective study of all patients treated with computed tomography guided RFA for multifocal renal neoplasms at one institution. Fifty-seven subjects, mean age 70 (range 37-88) years, underwent RFA of 169 renal neoplasms (average size 2.0 cm). Subjects had between 2 and 8 (mean 2.96) neoplasms ablated. Estimated glomerular filtration rate (eGFR) was measured before and after RFA. Complications related to RFA were recorded.

RESULTS

eGFR decreased on average of 4.4 % per tumor treated and 6.7 % per ablation session (average 1.76 tumors treated per session). For subjects with the largest neoplasm measuring >3 cm, eGFR decreased an average of 14.5 % during the course of their treatment. If the largest neoplasm measured 2-3 cm, eGFR decreased an average of 7.7 %, and if the largest neoplasm measured <2 cm, eGFR decreased an average of 3.8 %. Subjects with reduced baseline renal function were more likely to have a greater decline in eGFR after RFA. There was a minor complication rate of 6.3 % (6 of 96 sessions), none of which required treatment, and a major complication rate of 4.2 % (4 of 96 sessions).

CONCLUSION

RFA for the treatment of multifocal renal neoplasms results in mild decline of renal function.

Wide range and variation in minimally invasive surgery for renal malignancy in Japan: a population-based analysis

BACKGROUND

Despite increasing interest in minimally invasive surgery, prevalence data are completely absent. Our objective was to analyze clinico-epidemiological variations of surgery for renal malignancy in Japan with emphasis on annual trends and regional gaps, and to analyze factors affecting choice of open versus minimally invasive surgery.

METHODS

We identified patients who underwent open (n = 8646), laparoscopic (n = 5932), or minimum incision endoscopic surgery (MIES) (n = 381) nephrectomy for renal malignancy, using the Japanese Diagnosis Procedure Combination database, 2007-2010. Clinical and regional variations in these three approaches were determined, and the annual per-population incidence of nephrectomy was estimated. Multivariate logistic regression was used to analyze factors affecting choice of minimally invasive surgery (laparoscopy or MIES).

RESULTS

The proportion of open nephrectomy decreased from 65.3 % in 2007 to 51.6 % in 2010. Laparoscopic nephrectomy accounted for 51.0 % of procedures for T1 tumors. The estimated incidence of nephrectomy in males and females was 14.3 and 6.1 per 100,000 person-years, respectively. Multivariate analysis showed that minimally invasive nephrectomy was more likely to be selected for patients in their 30-50s who had less comorbidity, better performance status, or lower TNM stage, in high-volume or academic hospitals, especially in western Japan. Hemodialysis use was a favorable factor.

CONCLUSION

Despite differences between eastern and western Japan, minimally invasive surgery is becoming widespread throughout Japan, especially for patients with low operative risks and early-stage cancer who are hospitalized in high-volume institutes.

Long-term outcomes of renal tumor radio frequency ablation stratified by tumor diameter: size matters

PURPOSE

Renal tumor size influences the efficacy of radio frequency ablation but identification of confident size cutoffs has been limited by small numbers and short followup. We evaluated tumor size related outcomes after radio frequency ablation for patients with adequate (greater than 3 years) followup.

MATERIALS AND METHODS

We identified 159 tumors treated with radio frequency ablation as primary treatment. Disease-free survival was defined as the time from definitive treatment to local recurrence, detection of metastasis or the most recent imaging showing no evidence of disease. Patients were evaluated with contrast enhancing imaging preoperatively, and at 6 weeks, 6 months and at least annually thereafter.

RESULTS

Median tumor size was 2.4 cm (range 0.9 to 5.4) with a median followup of 54 months (range 1.5 to 120). Renal cell carcinoma was confirmed in 72% of the 150 tumors that had pre-ablation biopsy (94%). The 3 and 5-year disease-free survival was comparable at 92% and 91% overall, and was dependent on tumor size, being 96% and 95% for tumors smaller than 3.0 cm and 79% and 79%, respectively, for tumors 3 cm or larger (p=0.001). Most failures (14 of 18) were local, either incomplete ablations or local recurrences. This is an intent to treat analysis and, therefore, includes patients ultimately found to have benign tumors, although outcomes were comparable in patients with cancer.

CONCLUSIONS

Radio frequency ablation treatment success of the small renal mass is strongly correlated with tumor size. Radio frequency ablation provides excellent and durable outcomes, particularly in tumors smaller than 3 cm. Of tumors 3 cm or larger, approximately 20% will recur such that alternative treatment techniques should be considered. However, most treatment failures are local and are often successfully treated with another ablation session.

Diabetes and risk of renal cell carcinoma

Background and objectives: There is evidence that the incidence of solid tumors is markedly increased in patients with diabetes mellitus. In the current study, we investigate the association between diabetes and renal cancer.

Patients and Methods: A single-center retrospective analysis of 473 patients who underwent nephrectomy for renal cell carcinoma (RCC) was performed. Diabetic RCC patients were screened for age, gender, ethnicity, HgA1C, glucose levels and renal function.

Results: Of the 473 cases with RCC, we identified 120 patients (25.4%) with a history of diabetes. The incidence of diabetes in RCC patients was higher in female than male subjects and in Hispanic compared to White and Other ethnic backgrounds. At diagnosis, the majority of diabetic RCC patients were 50-59 years of age. In diabetic RCC cases, clear cell type histology (92.0%), nuclear grade 2 (56.1%) and tumor size range from 1-5 cm (65.7%) were the most common in each category.

Conclusion: Our findings indicate that diabetic RCC patients have a predominance of localized, small clear cell RCC. In addition, females with a history of RCC have a higher frequency of diabetes compared to males. This is the first report of clinical and histopathological features of RCC associated with diabetes.

Characteristics of aggressive variants in T1a renal cell carcinoma

PURPOSE

To explore factors associated with metastasis and prognosis in T1a renal cell carcinoma (RCC).

METHODS

We retrospectively reviewed 451 cases of sporadic T1aRCC among 1,060 patients admitted to the Department of Urology at Hamamatsu University Hospital and affiliated hospitals between 1978 and 2007. Clinicopathological factors were analyzed for metastatic and prognostic risks.

RESULTS

We identified 32 RCC patients with metastatic disease, 22 with synchronous and 10 with metachronous metastatic RCC. Patients with metastatic disease had a significantly higher incidence of symptomatic cancer, as well as greater tumor size, C-reactive protein (CRP) level, sarcomatoid component ratio, histological grade 3 and microvascular invasion than those without metastasis. Among the 32 patients with metastasis, there is no significant difference in clinicopathological factors. The most common site of metastasis was bone. Among patients with metastatic T1aRCC, findings at diagnosis of a symptomatic cancer, CRP level of 0.4 mg/dL or more, tumor size of 3.0 cm or greater, histological grade 3, a sarcomatoid component and microvascular invasion appeared to be significant and independent risk factors. Significant independent risk factors with metachronous metastatic RCC were a symptomatic cancer and a sarcomatoid component at diagnosis. A CRP level of 0.4 mg/dL or more was also an independent prognostic factor for overall survival.

CONCLUSION

RCC patients with findings at diagnosis of a symptomatic cancer, a sarcomatoid component and CRP level of 0.4 mg/dL or more require intensive follow-up.

Reassessment of renal cell carcinoma lymph node staging: analysis of patterns of progression

OBJECTIVES

To evaluate the prognostic value of lymph node (LN) metastasis and the therapeutic role of LN dissection (LND) in patients with renal cell carcinoma.

METHODS

We reviewed the medical records of 1503 patients who had undergone nephrectomy from 1990 to 2007. The patients were stratified according to the number, location, and size of LN metastases. The disease-free survival, cancer-specific survival, and survival relative to the preoperative suspicion of LN metastasis were analyzed.

RESULTS

Of the 1503 patients, 726 (48.3%) had Stage pN0, 37 (2.5%) had Stage pN+, including 16 with pN1 and 21 with pN2, and 740 (49.2%) had Stage pNx. The average number of LNs removed was 5 (range 1-33), and the average size of the metastasized LNs was 2.4 cm (range 0.8-6). Of the patients without preoperative clinical evidence of LN metastasis, 203 underwent LND; all had Stage pN0. The LN stage was a significant predictor of distant metastasis-free survival (P = .002) and cancer-specific survival (P = .001) between the pNx/pN0 and pN+ groups but not between the pN1 and pN2 groups. Metastasized LN size (<3 vs ≥3 cm) also significantly predicted for distant metastasis-free survival (P = .003) and cancer-specific survival (P = .001). In LN-positive patients, LND improved local recurrence-free survival but not distant metastasis-free survival or cancer-specific survival.

CONCLUSIONS

The current LN staging system, which is dependent on the number of metastatic LNs, did not significantly correlate with the prognosis in patients with renal cell carcinoma. In contrast, LN size (<3 vs ≥3 cm) better reflected the effect of this disease on survival. The therapeutic role of LND might be limited.

The beginning of the 21st century: a paradigm shift in the surgical management of renal cell carcinoma in South America

PURPOSE

The incidence of renal cell carcinoma (RCC) has been rising by 2.3 to 4.3% every year over the past three decades. Previously, RCC has been known as the internist's tumor; however, it is now being called the radiologist's tumor because 2÷3 are now detected incidentally on abdominal imaging. We compared patients who were treated toward the end of the 20th century to those treated during the beginning of the 21st century with regard to RCC size and type of surgical treatment.

MATERIALS AND METHODS

The study included 226 patients. For analysis of tumor size, we considered a cut point of <4 cm and>4 cm. For analysis of type of surgery performed, we considered radical and partial nephrectomy.

RESULTS

After the turn of the century, there was a reduction of 1.57±0.48 cm in the size of the RCC that was operated on. Nephron sparing surgeries were performed in 17% of the cases until the year 2000, and 39% of the tumors were <4 cm. From 2001, 64% of the tumors measured<4 cm and 42% of the surgeries were performed using nephron sparing techniques. Mean tumor size was 5.95 cm (±3.58) for the cases diagnosed before year 2000, and cases treated after the beginning of 21st century had a mean tumor size of 4.38 cm (±3.27).

CONCLUSIONS

Compared with the end of the 20th century, at the beginning of the 21st century due to a reduction in tumor size it was possible to increase the number of nephron sparing surgeries.

Percutaneous cryoablation of renal tumors: patient selection, technique, and postprocedural imaging

Percutaneous cryoablation of renal tumors requires a number of important steps for success and relies heavily on imaging for treatment planning, intraprocedural guidance and monitoring, detection of untreated tumor, and surveillance for disease progression. Imaging-guided percutaneous cryoablation has several advantages over laparoscopic cryoablation. In particular, computed tomography (CT) and magnetic resonance (MR) imaging allow global evaluation of the ablation zone and an accurate depiction of the treatment margin. Ultrasonography allows real-time guidance of probe placement but cannot help depict ice ball formation as accurately as CT or MR imaging. Multiphasic CT or MR imaging should be performed at structured intervals following ablation. Treated tumors are expected to decrease in size over time, and lesion growth and internal or nodular enhancement are suspicious for tumor recurrence or progression. Complications include probe site pain, hematoma, incomplete ablation, and recurrent tumor. Current limitations of percutaneous cryoablation include the inability to control hemorrhage without intraarterial access and a lack of long-term follow-up data. Nevertheless, percutaneous cryoablation is an effective choice for minimally invasive nephron-sparing treatment of renal tumors.

Extracolonic findings at CT colonography

Computed tomographic colonography (CTC) is a validated tool for the evaluation of the colon for polyps and cancer. The technique employed for CTC includes a low-dose CT scan of the abdomen and pelvis that is typically performed without the administration of intravenous contrast. Using this technique it is possible to discover findings outside of the colon. By far, most extracolonic findings are determined to be clinically inconsequential on CTC and most patients are not recommended for further testing. However, some findings may result in additional diagnostic evaluation or intervention, which can lead to patient anxiety and increased morbidity and health care costs. Alternatively, some findings can lead to the earlier diagnosis of a clinically significant lesion, which could result in decreased patient morbidity and mortality as well as overall savings in downstream health care costs. The controversies of detecting and evaluating these incidental extracolonic findings on CTC are discussed.

Incidental findings found in "healthy" volunteers during imaging performed for research: current legal and ethical implications

Incidental findings found in "healthy" volunteers during research imaging are common and have important implications for study design and performance, particularly in the areas of informed consent, subjects' rights, clinical image analysis and disclosure. In this study, we aimed to determine current practice and regulations concerning information that should be given to research subjects when obtaining consent, reporting of research images, who should be informed about any incidental findings and the method of disclosure. We reviewed all UK, European and international humanitarian, legal and ethical agencies' guidance. We found that the guidance on what constitutes incidental pathology, how to recognise it and what to do about it is inconsistent between agencies, difficult to find and less complete in the UK than elsewhere. Where given, guidance states that volunteers should be informed during the consent process about how research images will be managed, whether a mechanism exists for identifying incidental findings, arrangements for their disclosure, the potential benefit or harm and therapeutic options. The effects of incidentally discovered pathology on the individual can be complex and far-reaching. Radiologist involvement in analysis of research images varies widely; many incidental findings might therefore go unrecognised. In conclusion, guidance on the management of research imaging is inconsistent, limited and does not address the interests of volunteers. Improved standards to guide management of research images and incidental findings are urgently required.

Perfusion-CT monitoring of cryo-ablated renal cells tumors

Background

No single and thoroughly validated imaging method in monitoring of cryoablated renal cell carcinoma (RCC) is available. The purpose of our study was to determine the feasibility of dynamic contrast-enhanced perfusion CT (pCT) in evaluating the hemodynamic response of RCC.

Methods

15 patients (14 male, 1 female; age range, 43-81 years; mean age, 62 years) with cryoablated RCC via a transperitoneal approach, underwent to pCT 6-8 months after cryo-therapy. pCT was performed for 65 seconds after intravenous injection of contrast medium (80 mL, 370 mg iodine per millilitre, 4 mL/sec). Perfusion parameters (Time/Density curve; Blood flow, BF; Blood Volume, BV; Mean Transit Time, MTT; Permeability-Surface Area Product, PS) were sampled in the cryoablated tumor area and in ipsilateral renal cortex using deconvolution-based method. A tumor was considered to be not responsive to treatment by CT evidence of pathological contrast enhancement in the cryoablated area or renal mass persistence compared with the preoperative CT control. Written informed consent was obtained from all participants before the study.

Results

After cryotherapy, successfully ablated tumor (n = 13) showed decrease in BV (5,39 +/- 1,28 mL/100 g), BF (69,92 +/- 20,12 mL/100 g/min) and PS (16,66 +/- 5,67 mL/100 g/min) value and increased value of MTT (25,35 +/- 4,3 sec) compared with those of normal renal cortex (BV: 117,86 +/- 31,87 mL/100 g/min; BF: 392,39 +/- 117,32 mL/100 g/min; MTT: 18,02 +/- 3,6 sec; PS: 81,68 +/- 22,75 mL/100 g/min). In one patient, assessment of perfusion parameters was not feasible for breathing artifacts. One tumor showed poor response to treatment by the evidence of nodular contrast enhancement in the region encompassing the original lesion. Two typical enhancement patterns were obtained comparing the Time-Density curves of responsive and not responsive ablated tumors.

Conclusion

Perfusion CT seems to be a feasible and promising technique in monitoring the effects of cryoablation therapy.

Imaging and management of the incidentally discovered renal mass

Improvements in imaging technology and the expanding use of imaging have led to a rapid increase in the discovery of incidental renal lesions. These can present both the radiologist and the referring clinician with diagnostic dilemmas. This article addresses the most frequently encountered lesions and provides a framework for the diagnostic and management pathways for both solid and cystic lesions.