Radiofrequency ablation versus nephron-sparing surgery for small unilateral renal cell carcinoma: cost-effectiveness analysis

Early-Stage Renal Cell Carcinoma Locoregional Therapies: Current Approaches and Future Directions

Renal cell carcinoma (RCC) is the most common primary renal malignancy. Prevalence of RCC in developed countries has slowly increased. Although partial or total nephrectomy has been the first-line treatment for early-stage RCC, improved or similar safety and treatment outcomes with locoregional therapies have challenged this paradigm. In this review, we explore locoregional techniques for early-stage RCC, including radiofrequency ablation, cryoablation, and microwave ablation with a focus on procedural technique, patient selection, and safety/treatment outcomes. Furthermore, we discuss future advances and novel techniques, including radiomics, combination therapy, high-intensity focused ultrasound, and catheter-directed techniques.

Cost-effectiveness analysis of microwave ablation versus robot-assisted partial nephrectomy for patients with small renal masses in Australia

OBJECTIVES

Microwave ablation (MWA) has gained attention as a minimally invasive and safe alternative to surgical intervention for patients with small renal masses; however, its cost-effectiveness in Australia remains unclear. This study conducted a cost-effectiveness analysis to evaluate the relative clinical and economic merits of MWA compared to robotic-assisted partial nephrectomy (RA-PN) in the treatment of small renal masses.

METHODS

A Markov state-transition model was constructed to simulate the progression of Australian patients with small renal masses treated with MWA versus RA-PN over a 10-year horizon. Transition probabilities and utility data were sourced from comprehensive literature reviews, and cost data were estimated from the Australian health system perspective. Life-years, quality-adjusted life-years (QALYs), and lifetime costs were estimated. Modelled uncertainty was assessed using both deterministic and probabilistic sensitivity analyses. A willingness-to-pay (WTP) threshold of $50,000 per QALY was adopted. All costs are expressed in 2022 Australian dollars and discounted at 3% annually. To assess the broader applicability of our findings, a validated cost-adaptation method was employed to extend the analysis to 8 other high-income countries.

RESULTS

Both the base case and cost-adaptation analyses revealed that MWA dominated RA-PN, producing both lower costs and greater effectiveness over 10 years. The cost-effectiveness outcome was robust across all model parameters. Probabilistic sensitivity analyses confirmed that MWA was dominant in 98.3% of simulations at the designated WTP threshold, underscoring the reliability of the model under varying assumptions.

CONCLUSION

For patients with small renal masses in Australia and comparable healthcare settings, MWA is the preferred strategy to maximize health benefits per dollar, making it a highly cost-effective alternative to RA-PN.

[Nephron sparing in the management of localized solid renal mass]

Managing a malignant renal tumor requires, first of all, a reflection on the necessity of its treatment. It must consider the renal function, altered at the time of diagnosis in 50% of cases. The treatment method chosen depends on many factors, in particular, the predicted residual renal function, the risk of chronic kidney disease, the need for temporary or long-term dialysis, and overall long-term survival. Other factors include the size, position, and number of tumors and a hereditary tumor background. When a renal-sparing management alternative is available, total nephrectomy should no longer be performed in patients with small malignant renal masses (cT1a). This may consist of surgery (partial nephrectomy or lumpectomy), percutaneous thermo-ablation (by radiofrequency, microwave, or cryotherapy). In patients with limited life expectancy, imaging-based surveillance may be proposed to suggest treatment in case of local progression. Good coordination between urologist, radiologist, nephrologist, and sometimes radiotherapist should allow optimal management of patients with a malignant renal tumor with or without underlying renal failure.

Percutaneous cryoablation of 100 anterior renal tumors: safety and technical success

PURPOSE

To assess the safety, technical success, and clinical outcomes of percutaneous cryoablation (PCA) in patients with anterior renal tumors.

METHODS

A retrospective analysis of patients with anterior renal tumors, defined as tumors at or anterior to the level of the renal pelvis, treated with CT-guided PCA from 2008 to 2022. Summary statistics included demographics and baseline tumor attributes. Treatment and follow-up metrics included primary and secondary technical success, adverse events (AEs) according to the SIR classification, local recurrence, overall survival (OS), and cancer-specific survival (CSS)). 100 patients (60 males; mean age: 63, mean BMI: 33, mean Charlson comorbidity index:6) with 100 anterior renal tumors were included.

RESULTS

78% of tumors were T1a and 22% T1b with mean maximal tumoral dimension of 29 mm (range: 6-62 mm) and mean distance to nearest critical structure 9 mm (range: 0-40 mm). Mean follow-up was 20.9 months (range: 3-103). 28% of PCAs required hydrodissection. Technical success was achieved in 92% of patients; with six remaining patients undergoing successful repeat PCA (secondary technical success: 98%). The remaining two patients without primary technical success were either surveilled or had a benign pathology on resulted concomitant biopsy. Four patients (4%) had major AEs (hemorrhage requiring prolonged admission, transfusion, or embolization (n = 3), perinephric abscess requiring drainage (n = 1)) and 27% had minor AEs. Eight patients (8%) had recurrence with a one-year OS of 94% and CSS of 100%. All recurrences underwent repeat ablation without additional recurrence and 3/8 (38%) were T1b and 5/8 (63%) were T1a tumors.

CONCLUSION

PCA of anterior renal tumors can be performed safely with high rates of technical and oncologic success.

Clinical and Economic Evaluation of Ultrasound-Guided Radiofrequency Ablation vs. Parathyroidectomy for Patients with Primary Hyperparathyroidism: A Cohort Study

RATIONALE AND OBJECTIVES

To compare the clinical and economic effects of ultrasound (US)-guided radiofrequency ablation (RFA) with parathyroidectomy (PTX) for primary hyperparathyroidism (PHPT).

MATERIALS AND METHODS

From April 2014 to April 2021, 123 PHPT patients who received US-guided RFA or PTX were studied. Propensity score (PS) matching was used to balance the baseline data of the two groups. The rates of cure, recurrent and persistent PHPT, and complications were compared. A Chinese healthcare system perspective cost minimization analysis was conducted.

RESULTS

After PS matching, 37 patient pairs (1:1) were created for the two groups. Follow-up was 27.2 ± 10.6 months and 28.8 ± 16.1 months for the RFA and PTX groups, respectively. At the last follow-up, there was no evidence of differences regarding clinical cure rate between the two groups (RFA vs. PTX, 91.9% vs. 94.6%, p = 1.000). Recurrent PHPT did not develop in any patient. One patient in each group had persistent PHPT. The incidence of complications and side effects, except postoperative pain (RFA vs. PTX, 16.2% vs. 40.5%, p = 0.020), were no significant difference between the two groups (all, p > 0.05). The incremental cost was -$284.00; thus, RFA was more cost-effective. For patients with employee medical insurance or resident medical insurance, the incremental costs (RFA vs. PTX) were -$391.94 and -$49.43, respectively.

CONCLUSION

There were no significant differences in efficacy and safety between RFA and PTX. As the incremental cost for RFA compared with PTX was negative, RFA may be used as a more cost-effective nonsurgical treatment alternative for PHPT.

Cost-effectiveness of minimally invasive partial nephrectomy and percutaneous cryoablation for cT1a renal cell carcinoma

BACKGROUND

There is growing evidence that partial nephrectomy (PN) and percutaneous cryoablation (PCA) yield comparable outcomes for patients with cT1a renal cell carcinoma (RCC), although the cost-effectiveness of both treatments still needs to be assessed.

PURPOSE

To perform a cost-effectiveness analysis of PN and PCA for patients with cT1a RCC.

MATERIALS AND METHODS

A decision analysis was created over a 5-year span from a healthcare payer's perspective computing expected costs and outcomes of PN and PCA in terms of quality-adjusted life-years (QALYs) and incremental cost-effectiveness (ICER). After each treatment, the following states were modelled using data from the recent literature: procedural complications, no evidence of disease (NED), local recurrence, metastases, and death from RCC- or non-RCC-related causes. Probabilistic and deterministic sensitivity analyses were performed.

RESULTS

PCA and PN yielded health benefits of 3.68 QALY and 3.67 QALY. Overall expected costs were $20,491 and $26,478 for PCA and PN. On probabilistic sensitivity analysis, PCA was more cost-effective than PN in 84.78% of Monte Carlo simulations. PCA was more cost-effective until its complication risk was at least 38% higher than PN. PCA was more cost-effective than PN when (i) PCAs annual local recurrence risk was < 3.5% higher than that of PN in absolute values; (ii) PCAs annual metastatic risk was < 1.0% higher than that of PN; or (iii) PCAs annual cancer-specific mortality risk < 0.65% higher than that of PN. PCA remained cost-effective until its procedural cost is above $13,875.

CONCLUSION

PCA appears to be more cost-effective than PN for the treatment of cT1a RCC, although the currently available evidence is of limited quality. PCA may be the better treatment strategy in the majority of scenarios varying procedural complications, recurrence, metastatic risk, and RCC-mortality in clinically plausible ranges.

KEY POINTS

• For patients with cT1a RCCs, PCA yields a comparable health benefit at lower costs compared to PN, making PCA the dominant and therefore more cost-effective treatment strategy over PN. • PCA was more cost-effective than PN when (i) PCAs annual local recurrence risk was < 3.5% higher than PN in absolute values; (ii) PCAs annual metastatic risk was < 1.0% higher than PN; or (iii) PCAs annual cancer-specific mortality risk < 0.65% higher than PN. • PCA is more cost-effective than PN for the treatment of cT1a RCC, and it remained so in the majority of scenarios varying procedural complications, recurrence, metastatic risk, and RCC mortality.

Microwave Ablation versus Stereotactic Body Radiotherapy for Stage I Non-Small Cell Lung Cancer: A Cost-Effectiveness Analysis

PURPOSE

To assess the cost-effectiveness of microwave ablation (MWA) and SBRT for patients with inoperable stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

A literature search was performed in MEDLINE with broad search clusters. A decision-analysis model was constructed over a 5-year period. The model incorporated treatment-related complications and long-term recurrence. All clinical parameters were derived from the literature with preference to long-term prospective trials. A healthcare payers' perspective was adopted. Outcomes were measured in quality-adjusted life years (QALY) extracted from prior studies and United States dollars from Medicare reimbursements and prior studies. Base case calculations, probabilistic sensitivity analysis with 10,000 Monte Carlo simulations, and multiple one- and two-way sensitivity analyses were performed.

RESULTS

MWA yielded a health benefit of 2.31 QALY at a cost of $195,331, whereas SBRT yielded a health benefit of 2.33 QALY at a cost of $225,271. The incremental cost-effectiveness ratio was $1,480,597/QALY, indicating that MWA is the more cost-effective strategy. The conclusion remains unchanged in probabilistic sensitivity analysis with MWA being the optimal cost strategy in 99.84% simulations. One-way sensitivity analyses revealed that MWA remains cost-effective when its annual recurrence risk is below 18.4% averaged over 5 years, when the SBRT annual recurrence risk is above 1.44% averaged over 5 years, or when MWA is at least $7,500 cheaper than SBRT.

CONCLUSION

Microwave ablation appears to be a more cost-effective than stereotactic body radiotherapy for patients with inoperable stage I non-small cell lung cancer.

Percutaneous Cryoablation versus Robot-Assisted Partial Nephrectomy of Renal T1A Tumors: a Single-Center Retrospective Cost-Effectiveness Analysis

PURPOSE

To evaluate the cost-effectiveness of percutaneous cryoablation (PCA) versus robot-assisted partial nephrectomy (RPN) in patients with small renal tumors (T1a stage), considering perioperative complications.

MATERIALS AND METHODS

Retrospective study from November 2008 to April 2017 of 122 patients with a T1a renal mass who after being analyzed by a multidisciplinary board underwent to PCA (59 patients) or RPN (63 patients). Hospital costs in US dollars, and clinical and tumor data were compared. Non-complicated intervention was considered as an effective outcome. A hypothetical model of possible complications based on Clavien-Dindo classification (CDC) was built, grouping them into mild (CDC I and II) and severe (CDC III and IV). A decision tree model was structured from complications of published data.

RESULTS

Patients who underwent PCA were older (62.5 vs. 52.8 years old, p < 0.001), presented with more coronary disease and previous renal cancer (25.4% vs. 10.1%, p = 0.023 and 38% vs. 7.2%,  p < 0.001, respectively). Patients treated with PCA had a higher preoperative risk (American Society of Anesthesiologists-ASA ≥ 3) than those in the RPN group (25.4% vs. 0%, p < 0.001). Average operative time was significantly lower with PCA than RPN (99.92 ± 29.05 min vs. 129.28 ± 54.85 min, p < 0.001). Average hospitalization time for PCA was 2.2 ± 2.95 days, significantly lower than RPN (mean 3.03 ± 1.49 days, p = 0.04). The average total cost of PCA was significantly lower than RPN (US$12,435 ± 6,176 vs. US$19,399 ± 6,047, p < 0.001). The incremental effectiveness was 5% higher comparing PCA with RPN, resulting a cost-saving result in favor of PCA.

CONCLUSION

PCA was the dominant strategy (less costly and more effective) compared to RPN, considering occurrence of perioperative complications.

Cost effectiveness and the role of the National Institute of Health and Care Excellence (NICE) in interventional radiology

Healthcare expenditure is continually increasing and projected to accelerate in the future, with an increasing proportion being spent on interventional radiology. The role of cost effectiveness studies in ensuring the best allocation of resources is discussed, and the role of National Institute of Health and Care Excellence (NICE) in determining this. Issues with demonstrating cost effectiveness have been discussed, and it has been found that there is significant scope for improving cost effectiveness, with suggestions made for how this can be achieved. In this way, more patients can benefit from better treatment given limited healthcare budgets.

Cost-effectiveness of dual-energy CT versus multiphasic single-energy CT and MRI for characterization of incidental indeterminate renal lesions

PURPOSE

To evaluate the cost-effectiveness of DECT versus multiphasic CT and MRI for characterizing small incidentally detected indeterminate renal lesions using a Markov Monte Carlo decision-analytic model.

BACKGROUND

Incidental renal lesions are commonly encountered due to the increasing utilization of medical imaging and the increasing prevalence of renal lesions with age. Currently recommended imaging modalities to further characterize incidental indeterminate renal lesions have some inherent drawbacks. Single-phase DECT may overcome these limitations, but its cost-effectiveness remains uncertain.

MATERIALS AND METHODS

A decision-analytic (Markov) model was constructed to estimate life expectancy and lifetime costs for otherwise healthy 64-year-old patients with small (≤ 4 cm) incidentally detected, indeterminate renal lesions on routine imaging (e.g., ultrasound or single-phase CT). Three strategies for evaluating renal lesions for enhancement were compared: multiphase SECT (e.g., true unenhanced and nephrographic phase), multiphasic MRI, and single-phase DECT (nephrographic phase in dual-energy mode). The model incorporated modality-specific diagnostic test performance, incidence, and prevalence of incidental renal cell carcinomas (RCCs), effectiveness, costs, and health outcomes. An incremental cost-effectiveness analysis was performed to identify strategy preference at willingness-to-pay (WTP) thresholds of $50,000 and $100,000 per quality-adjusted life-year (QALY) gained. Deterministic and probabilistic sensitivity analysis were performed.

RESULTS

In the base case analysis, expected mean costs per patient undergoing characterization of incidental renal lesions were $2567 for single-phase DECT, $3290 for multiphasic CT, and $3751 for multiphasic MRI. Associated quality-adjusted life-years were the highest for single-phase DECT at 0.962, for multiphasic MRI it was 0.940, and was the lowest for multiphasic CT at 0.925. Because of lower associated costs and higher effectiveness, the single-phase DECT strategy dominated the other two strategies.

CONCLUSIONS

Single-phase DECT is potentially more cost-effective than multiphasic SECT and MRI for evaluating small incidentally detected indeterminate renal lesions.

Early trends and predictors of renal function following computed tomography-guided percutaneous cryoablation of a renal mass in patients with and without prior renal impairment

OBJECTIVE

To assess trends and predictors of the glomerular filtration rate (GFR) after renal mass cryoablation in patients with and without history of renal impairment.

MATERIALS AND METHODS

This was a retrospective study of 39 patients who underwent computed tomography-guided percutaneous cryoablation of a renal mass, divided into two groups: those with prior renal impairment (PRI+); and those without prior renal impairment (PRI-). The GFR trend and the chronic kidney disease stage were evaluated at baseline, as well as at 1, 6, and 12 months after cryoablation. Predictors of GFR at 1 and 6 months were modeled with linear regression.

RESULTS

In both groups, the mean GFR at 1 month and 6 months was significantly lower than at baseline (p < 0.001 and p = 0.01, respectively). Although the GFR was lower across all time points in the PRI+ group (-26.1; p < 0.001), the overall trend was not statistically different from that observed in the PRI- group (p = 0.89). Univariate analysis showed that the decline in GFR at 1 and 6 months correlated with the baseline GFR (0.77 and 0.63; p < 0.001 and p = 0.03, respectively) and with the size of the ablation zone (-7.6 and -12.84, respectively; p = 0.03 for both). However, in the multivariate model, baseline GFR was predictive only of GFR at 1 month (p < 0.001).

CONCLUSION

The trend in GFR decline after cryoablation is similar for patients with and without a history of renal impairment. Baseline GFR predicts the mean GFR in the early post-cryoablation period.

Percutaneous Image-guided Thermal Ablation for Renal Cell Carcinoma

Nephrectomy is the gold standard for the treatment of renal cell carcinoma (RCC). However, some patients are not suitable candidates for nephrectomy because of high surgical risk, reduced renal function, or the presence of multiple renal tumors. Percutaneous image-guided thermal ablation, including cryoablation and radiofrequency ablation, is a minimally invasive and highly effective treatment and can be used to treat RCC in patients who are not good candidates for surgery. This article will review percutaneous image-guided thermal ablation for RCC, covering treatment indications, ablation modalities and techniques, oncologic outcomes, and possible complications. In addition, the characteristics of each ablation modality and its comparison with nephrectomy are also presented.

Active Surveillance Versus Nephron-Sparing Surgery for a Bosniak IIF or III Renal Cyst: A Cost-Effectiveness Analysis

OBJECTIVE

The objective of our study was to evaluate the cost-effectiveness of active surveillance (AS) versus nephron-sparing surgery (NSS) in patients with a Bosniak IIF or III renal cyst.

MATERIALS AND METHODS

Markov models were developed to estimate life expectancy and lifetime costs for 60-year-old patients with a Bosniak IIF or III renal cyst (the reference cases) managed by AS versus NSS. The models incorporated the malignancy rates, reclassification rates during follow-up, treatment effectiveness, complications and costs, and short- and long-term outcomes. An incremental cost-effectiveness analysis was performed to identify management preference under an assumed $75,000 per quality-adjusted life-year (QALY) societal willingness-to-pay threshold, using data from studies in the literature and the 2015 Medicare Physician Fee Schedule. The effects of key parameters were addressed in a multiway sensitivity analysis.

RESULTS

The prevalence of malignancy for Bosniak IIF and III renal cysts was 26% (25/96) and 52% (542/1046). Under base case assumptions for Bosniak IIF cysts, the incremental cost-effectiveness ratio of NSS relative to AS was $731,309 per QALY for women, exceeding the assumed societal willingness-to-pay threshold, and AS outperformed NSS for both life expectancy and cost for men. For Bosniak III cysts, AS yielded greater life expectancy (24.8 and 19.4 more days) and lower lifetime costs (cost difference of $12,128 and $11,901) than NSS for men and women, indicating dominance of AS over NSS. Superiority of AS held true in sensitivity analyses for men 46 years old or older and women 57 years old or older even when all parameters were set to favor NSS.

CONCLUSION

AS is more cost-effective than NSS for patients with a Bosniak IIF or III renal cyst.

Personalized Treatment for Small Renal Tumors: Decision Analysis of Competing Causes of Mortality

Purpose To compare the effectiveness of personalized treatment for small (≤4 cm) renal tumors versus routine partial nephrectomy (PN), accounting for various competing causes of mortality. Materials and Methods A state-transition microsimulation model was constructed to compare life expectancy of management strategies for small renal tumors by using 1 000 000 simulations in the following ways: routine PN or personalized treatment involving percutaneous ablation for risk factors for worsening chronic kidney disease (CKD), and otherwise PN; biopsy, with triage of renal cell carcinoma (RCC) to PN or ablation depending on risk factors for worsening CKD; active surveillance for growth; and active surveillance when MRI findings are indicative of papillary RCC. Transition probabilities were incorporated from the literature. Effects of parameter variability were assessed in sensitivity analysis. Results In patients of all ages with normal renal function, routine PN yielded the longest life expectancy (eg, 0.67 years in 65-year-old men with nephrometry score [NS] of 4). Otherwise, personalized strategies extended life expectancy versus routine PN: in CKD stages 2 or 3a, moderate or high NS, and no comorbidities, MRI guidance for active surveillance extended life expectancy (eg, 2.60 years for MRI vs PN in CKD 3a, NS 10); and with Charlson comorbidity index of 1 or more, biopsy or active surveillance for growth extended life expectancy (eg, 2.70 years for surveillance for growth in CKD 3a, NS 10). CKD 3b was most effectively managed by using MRI to help predict papillary RCC for surveillance. Conclusion For patients with chronic kidney disease and small renal tumors, personalized treatment selection likely extends life expectancy. © RSNA, 2019 Online supplemental material is available for this article.

1000 consecutive ablation sessions in the era of computer assisted image guidance - Lessons learned

•

Computer assisted targeting techniques are simple to use and improve results in ablative tumour treatments.

•

The indications for ablative soft tissue tumour ablation are increasing.

•

Treatments are superior to resective surgery in terms of complications and hospitalization, oncological non-inferiority remains to be proven.

•

An incomplete ablation can be retreated without negative effects on survival.

•

Jet ventilation is an effective technique to minimize organ displacement during percutaneous or laparoscopic ablation.

Background

Ablation therapies for tumours are becoming more used as ablation modalities evolve and targeting solutions are getting better. There is an increasing body of long-term results challenging resection and proving lower morbidities and costs. The aim of this paper is to share the experiences from a high-volume centre in introducing computer assisted targeting solutions and efficient ablation modalities like microwave generators and irreversible electroporation.

Material and methods

One thousand consecutive treatments in one high-volume centre were evaluated retrospectively from prospectively collected data.

Results

The purpose of this paper is to present the benefits of going into computer assisted targeting techniques and microwave technology; pitfalls and overview of outcomes. The main target organ was the liver and the main indications were ablation of hepatocellular carcinomas and colorectal liver metastases. With the assistance of computer assisted targeting the local recurrence rate within 6 months has dropped from 30 to near 10%. The survival of patients with hepatocellular carcinoma and colorectal liver metastases is not worse if the tumour can be retreated after a local recurrence. Multiple colorectal liver metastases can be treated successfully.

Discussion

The incorporation of computer assisted targeting technologies for ultrasound-, ct guided- and laparoscopic tumour ablation has been very successful and without a noticeable learning curve. The same is true for switching from radiofrequency energies to microwave generators and irreversible electroporation.

Conclusion

It is well worthwhile upgrading ablation and targeting technologies to achieve excellent and reproducible results and minimizing operator dependency.

The Role of Ablation and Minimally Invasive Techniques in the Management of Small Renal Masses

CONTEXT

Nephron-sparing approaches are increasingly recommended for incidental small renal masses. Herein, we review the current literature regarding the safety and efficacy of focal therapy, including percutaneous ablation, for small renal masses.

OBJECTIVE

To summarize the application of ablative therapy in the management of small renal masses.

EVIDENCE ACQUISITION

PubMed and Medline database search was performed to look for findings published since 2000 on focal therapy for small renal masses. After literature review, 64 articles were selected and discussed.

EVIDENCE SYNTHESIS

Radiofrequency ablation and cryotherapy are the most widely used procedures with intermediate-term oncological outcome comparable with surgical series. Cost effectiveness seems excellent and side effects appear acceptable. To date, no randomized trial comparing percutaneous focal therapy with standard surgical approach or active surveillance has been performed.

CONCLUSIONS

Focal ablative therapies are now accepted as effective treatment for small renal tumors. For tumors <3cm, oncological effectiveness of ablative therapies is comparable with that of partial nephrectomy. Percutaneous ablation has fewer complications and a better postoperative profile when compared with minimally invasive partial nephrectomy.

PATIENT SUMMARY

Focal ablative therapies are now accepted as effective treatment for small renal tumors. For tumors <3cm, oncological effectiveness of ablative therapies is comparable with that of partial nephrectomy.

Quality of life outcomes in patients with localised renal cancer: a literature review

Purpose

Patients with localised renal cell carcinoma (RCC) can expect excellent oncologic outcomes. As such, there has been a shift towards maximising health-related quality of life (HRQoL). A greater understanding of HRQoL outcomes associated with different treatment options for RCC can facilitate patient-centred care, shared decision-making and enable cost utility analyses to guide health policies. The aim of this literature review was to evaluate the evidence regarding HRQoL following different management strategies for localised RCC.

Methods

Three databases were searched to identify studies reporting HRQoL in patients with localised renal cancer, including Medline, the Tuft’s Medical Centre Cost Effectiveness Analysis registry and the EuroQol website.

Results

Considerable methodological heterogeneity was noted. Laparoscopic nephrectomy was associated with significantly better short-term physical function compared to open surgery, although the effect on mental function was inconclusive. Nephron-sparing surgery was associated with better physical function compared to radical surgery. Patients’ perception of remaining renal function was a significant independent predictor of HRQoL, rather than surgery type. Tumour size, stage, post-operative complications, age, body mass index, occupational status, educational level and comorbidities were significant predictors of HRQoL. Only three studies were available regarding non-surgical management options and very little data were available regarding the impact of follow-up protocols and long-term effects of “cancer survivorship.”

Conclusion

There is a need for validated and reproducible RCC-specific HRQoL instruments and standardisation amongst studies to enable comparisons. Increased awareness regarding determinants of poor HRQoL may enable high-risk patients to receive tailored support.

Electronic supplementary material

The online version of this article (10.1007/s00345-018-2415-3) contains supplementary material, which is available to authorized users.

Cost and cost-effectiveness studies in urologic oncology using large administrative databases

OBJECTIVE

Urologic cancers are not only among the most common types of cancers, but also among the most expensive cancers to treat in the United States. This study aimed to review the use of CEAs and other cost analyses in urologic oncology using large databases to better understand the value of management strategies of these cancers.

METHODS

A literature review on CEAs and other cost analyses in urologic oncology using large databases.

RESULTS

The options for and costs of diagnosing, treating, and following patients with urologic cancers can be expected to rise in the coming years. There are numerous opportunities in each urologic cancer to use CEAs to both lower costs and provide high-quality services. Improved cancer care must balance the integration of novelty with ensuring reasonable costs to patients and the health care system.

CONCLUSION

With the increasing focus cost containment, appreciating the value of competing strategies in caring for our patients is pivotal. Leveraging methods such as CEAs and harnessing large databases may help evaluate the merit of established or emerging strategies.

Radiofrequency ablation for treatment of locally recurrent thyroid cancer presenting as a metastatic lymph node with dense macrocalcification: A case report and literature review

RATIONALE

Long-term recurrence rate of differentiated thyroid carcinoma has been reported to be as high as 30%. Repeat surgery may be challenging due to normal tissue plane distortion secondary to postoperative fibrosis, especially for small-sized recurrences. Recently, radiofrequency ablation (RFA) has been suggested to be a safe and effective alternative for high-risk patients or those who refuse surgery. Nonetheless, the efficacy of RFA remains questionable for densely calcified lymph nodes, which would have an increased likelihood of leaving residues after RFA.

PATIENT CONCERNS

We present a case of a successful combined treatment of a metastatic lymph node with dense macrocalcification with the use of a single RFA session and radioactive iodine (RAI) ablation in a patient with a previous history of total thyroidectomy and neck node dissection for papillary thyroid carcinoma.

DIAGNOSES

A 71-year-old man with papillary thyroid carcinoma underwent total thyroidectomy and neck node dissection followed by RAI ablation. The stimulated serum thyroglobulin level was 4.74 ng/mL at the time of RAI ablation, and the follow-up ultrasonography 3 months later revealed a 15-mm lymph node with dense macrocalcification at the right cervical level III.

INTERVENTIONS

After confirming metastasis on cytology, the lesion was treated with ultrasound-guided RFA.

OUTCOMES

The single RFA session combined with RAI ablation led to biochemical remission at 5 months after RFA, and complete resolution of structural recurrence including macrocalcification was observed 7 months after the second RAI (1 year after RFA). The patient remained free of recurrence at the 5-year follow-up.

LESSONS

RFA may offer a safe and effective alternative to 'berry picking' surgery in cases of surgical ineligibility or patient refusal of surgery even when the target lesions contain dense macrocalcification.

Decision Making: Thermal Ablation Options for Small Renal Masses

Renal cell carcinoma is a relatively common tumor, with an estimated 63,000 new cases being diagnosed in the United States in 2016. Surgery, be it with partial or total nephrectomy, is considered the mainstay of treatment for many patients. However, those patients with small renal masses, typically less than 3 to 4 cm in size who are deemed unsuitable for surgery, may be suitable for percutaneous thermal ablation. We review the various treatment modalities, including radiofrequency ablation, microwave ablation, and cryoablation; discuss the advantages and disadvantages of each method; and review the latest data concerning the performance of the various ablative modalities compared with each other, and compared with surgery.

Radiofrequency ablation of low-risk small papillary thyroidcarcinoma: preliminary results for patients ineligible for surgery

PURPOSE

The purpose of this study is to retrospectively evaluate the outcomes of radiofrequency ablation (RFA) of low-risk small papillary thyroid carcinomas (PTCs) in patients who were ineligible for surgery.

MATERIALS AND METHODS

Between 2005 and 2009, six PTCs (mean diameter, 0.92 cm; range, 0.6-1.3 cm) in six patients were treated with RFA by three radiologists in two hospitals. The inclusion criteria for this study were (1) pathologically confirmed PTC without cytological aggressiveness, (2) single PTC without extrathyroidal extension, (3) no metastatic tumours and (4) ineligibility for surgery. RFA was performed using a radiofrequency generator and an 18-gauge internally cooled electrode. The medical records were reviewed and analysed, focussing on the procedural profiles of RFA, symptoms and complications during and after RFA, and changes in tumours on follow-up ultrasonography.

RESULTS

Before and after RFA, the results of thyroid function tests were normal in all patients. During 48.5 ± 12.3 months (range, 36-65 months) of follow-up, along with a significant reduction in the mean volume (98.5 ± 3.3%), four ablation zones (4/6, 66.7%) completely disappeared. Two ablation zones exhibited only small calcified residues with nearly complete disappearance of the corresponding non-calcified solid portions, and in one of them, malignant cells were absent as assessed by fine-needle aspiration and core-needle biopsy. Transient hypertension with mild headache (n = 1) and mild neck pain (n = 1) developed during the procedure and subsided without any treatment.

CONCLUSION

Besides surgery and active surveillance, which are conflicting currently used management plans, RFA might represent an effective and a safe alternative for managing low-risk small PTCs, especially in patients ineligible for surgery.

Sociodemographic disparities in treatment and survival of small localized renal cell carcinoma: surgical resection versus thermal ablation

Aim: To investigate national practice trends in the use of surgical resection (SX) versus thermal ablation (TA) for the management of T1aN0M0 renal cell carcinoma with regard to sociodemographic factors and associated outcomes. Materials & methods: Patients diagnosed in 2004–2011 were identified using the Surveillance, Epidemiology and End Results registry. Sociodemographic factors predicting the use of surgery versus TA were determined using logistic regression. Cancer-specific survival was estimated using Kaplan–Meier method. Results: Overall, 19,136 (92.9%) patients underwent SX versus 1468 (7.1%) TA. Patients who were unmarried, diagnosed between 2008 and 2011, Caucasian, aged ≥70 years, insured, residing in Pacific Coast and Northern Plains, and in metropolitan areas with higher median family income had higher likelihoods of undergoing TA. Age-adjusted cancer-specific survival was similar in the two groups. Conclusion: Despite similar survival outcomes between SX versus TA, management of T1a renal cell carcinoma lesions may be influenced by a variety of nonclinical sociodemographic factors.

WITHDRAWN: Surgical management of localised renal cell carcinoma

This review is being updated and replaced following the publication of a protocol (Krabbe L‐M, Kunath F, Schmidt S, Miernik A, Cleves A, Walther M, Kroeger N. Partial nephrectomy versus radical nephrectomy for clinically localized renal masses [Protocol]. Cochrane Database of Systematic Reviews 2016, Issue 2. Art. No.: CD012045. DOI: 10.1002/14651858.CD012045) for a new review with a narrower scope. It will remain withdrawn when the new review is published.

The editorial group responsible for this previously published document have withdrawn it from publication.

Percutaneous Cryoablation vs Partial Nephrectomy: Cost Comparison of T1a Tumors

PURPOSE

To compare cost of percutaneous cryoablation vs open and robot-assisted partial nephrectomy of T1a renal masses from the hospital perspective.

MATERIALS AND METHODS

We retrospectively compared cost, clinical and tumor data of 37 percutaneous cryoablations to 26 open and 102 robot-assisted partial nephrectomies. Total cost was the sum of direct and indirect cost of procedural and periprocedural variables. Clinical data included demographics, Charlson Comorbidity Index (CCI), hospitalization time, complication rate, ICU admission rate, and 30-day readmission rates. Tumor data included size, RENAL nephrometry score, and malignancy rate. Student's t-test was used for continuous variables and Fisher's exact or chi-square tests for categorical data.

RESULTS

Mean total cost was lower for percutaneous cryoablation than open or robot-assisted partial nephrectomy: $6067 vs $11392 or $11830 (p<0.0001) with lower cost of procedure room: $1516 vs $3272 or $3254 (p<0.0001), room and board: $95 vs $1907 or $1106 (p<0.0001), anesthesia: $684 vs $1223 or $1468 (p<0.0001), and laboratory/pathology fees: $205 vs $804 or $720 (p<0.0001). Supply and device cost was higher than open: $2596 vs $1352 (p<0.0001), but lower than robot-assisted partial nephrectomy: $3207 (p=0.002). Mean hospitalization times were lower for percutaneous cryoablation (p<0.0001), while age and CCI were higher (p<0.0001). No differences in tumor size, nephrometry score, malignancy rate complication, ICU, or 30-day readmission rates were observed.

CONCLUSION

Percutaneous cryoablation can be performed at significantly lower cost than open and robotic partial nephrectomies for similar masses.

Radiation exposure from CT-guided ablation of renal masses: effects on life expectancy

OBJECTIVE. The purpose of this article is to project the effects of radiation exposure on life expectancy (LE) in patients who opt for CT-guided radiofrequency ablation (RFA) instead of surgery for renal cell carcinoma (RCC). MATERIALS AND METHODS. We developed a decision-analytic Markov model to compare LE losses attributable to radiation exposure in hypothetical 65-year-old patients who undergo CT-guided RFA versus surgery for small (≤ 4 cm) RCC. We incorporated mortality risks from RCC, radiation-induced cancers (for procedural and follow-up CT scans), and all other causes; institutional data informed the RFA procedural effective dose. Radiation-induced cancer risks were generated using an organ-specific approach. Effects of varying model parameters and of dose-reduction strategies were evaluated in sensitivity analysis. RESULTS. Cumulative RFA exposures (up to 305.2 mSv for one session plus surveillance) exceeded those from surgery (up to 87.2 mSv). In 65-year-old men, excess LE loss from radiation-induced cancers, comparing RFA to surgery, was 11.7 days (14.6 days for RFA vs 2.9 days for surgery). Results varied with sex and age; this difference increased to 14.6 days in 65-year-old women and to 21.5 days in 55-year-old men. Dose-reduction strategies that addressed follow-up rather than procedural exposure had a greater impact. In 65-year-old men, this difference decreased to 3.8 days if post-RFA follow-up scans were restricted to a single phase; even elimination of RFA procedural exposure could not achieve equivalent benefits. CONCLUSION. CT-guided RFA remains a safe alternative to surgery, but with decreasing age, the higher burden of radiation exposure merits explicit consideration. Dose-reduction strategies that target follow-up rather than procedural exposure will have a greater impact.

[Organ and kidney function preservation in renal cell carcinoma]

BACKGROUND

The organ-preserving partial nephrectomy has increasingly established itself in small unilateral renal tumours (<4 cm) with contralateral healthy kidney and counter gained in recent years in importance. There was found a significantly increased cardiovascular mortality rate and deteriorated quality of life, the more intact kidney tissue has been removed.

OBJECTIVES

In the present study, the influence of pre- and perioperative factors on direct postoperative course was examined, including 5-year survival rate and relapse behaviour after open organ-preserving partial nephrectomy in our own collective.

MATERIALS AND METHODS

In this retrospective study of 1657 patients were collected, who underwent surgery between 2007 and 2013 in the Department of Urology at the University Hospital Essen because of a renal tumour. 38 % of these operations (n = 636) were performed organ-preserving. In this trial there are factors identified that have an impact on need of blood transfusion and length of hospitalization in organ-preserving operation method.

RESULTS

No independent parameter can be determined for the need of blood transfusion. Tumour size and thus time of resection procedure does not affect the need of erythrocytes administration. In addition, the tumour size influences neither the postoperative serum-haemoglobin nor serum-creatinine. Increased patient age and female gender are identified as non-modifiable factors, which cause a longer hospitalisation. Postoperative pain therapy can be considered as a variable size, which does not affect the length of hospital stay. Modifiable factors that increase the overall length of stay, however, are the type of direct postoperative monitoring (ICU vs. anaesthetic recovery room) and the administration of blood transfusions.

CONCLUSIONS

There are constant factors, which can be associated with a longer residence time in the framework of an organ-preserving partial nephrectomy. Further there is shown evidence of the independence of the tumour size - in addition to proven good oncological results - of an extension of indication of organ-preserving nephrectomy of tumours > 4 cm.

Active surveillance, radiofrequency ablation, or cryoablation for the nonsurgical management of a small renal mass: a cost-utility analysis

BACKGROUND

Patients with a cortical small (≤4 cm) renal mass often are not candidates for or choose not to undergo surgery. The optimal management strategy for such patients is unclear.

METHODS

A decision-analytic Markov model was developed from the perspective of a third party payer to compare the quality-adjusted life expectancy and lifetime costs for 67-year-old patients with a small renal mass undergoing premanagement decision biopsy, immediate percutaneous radiofrequency ablation or percutaneous cryoablation (without premanagement biopsy), or active surveillance with serial imaging and subsequent ablation if needed.

RESULTS

The dominant strategy (most effective and least costly) was active surveillance with subsequent cryoablation if needed. On a quality-adjusted and discounted basis, immediate cryoablation resulted in a similar life expectancy (3 days fewer) but cost $3,010 more. This result was sensitive to the relative rate of progression to metastatic disease. Strategies that employed radiofrequency ablation had decreased quality-adjusted life expectancies (82-87 days fewer than the dominant strategy) and higher costs ($3,231-$6,398 more).

CONCLUSIONS

Active surveillance with delayed percutaneous cryoablation, if needed, may be a safe and cost-effective alternative to immediate cryoablation. The uncertainty in the relative long-term rate of progression to metastatic disease in patients managed with active surveillance versus immediate cryoablation needs to be weighed against the higher cost of immediate cryoablation. A randomized trial is needed directly to evaluate the nonsurgical management of patients with a small renal mass, and could be limited to the most promising strategies identified in this analysis.

Percutaneous cryoablation of metastatic renal cell carcinoma for local tumor control: feasibility, outcomes, and estimated cost-effectiveness for palliation

PURPOSE

To assess complications, local tumor recurrences, overall survival (OS), and estimates of cost-effectiveness for multisite cryoablation (MCA) of oligometastatic renal cell carcinoma (RCC).

MATERIALS AND METHODS

A total of 60 computed tomography- and/or ultrasound-guided percutaneous MCA procedures were performed on 72 tumors in 27 patients (three women and 24 men). Average patient age was 63 years. Tumor location was grouped according to common metastatic sites. Established surgical selection criteria graded patient status. Median OS was determined by Kaplan-Meier method and defined life-years gained (LYGs). Estimates of MCA costs per LYG were compared with established values for systemic therapies.

RESULTS

Total number of tumors and cryoablation procedures for each anatomic site are as follows: nephrectomy bed, 11 and 11; adrenal gland, nine and eight; paraaortic, seven and six; lung, 14 and 13; bone, 13 and 13; superficial, 12 and nine; intraperitoneal, five and three; and liver, one and one. A mean of 2.2 procedures per patient were performed, with a median clinical follow-up of 16 months. Major complication and local recurrence rates were 2% (one of 60) and 3% (two of 72), respectively. No patients were graded as having good surgical risk, but median OS was 2.69 years, with an estimated 5-year survival rate of 27%. Cryoablation remained cost-effective with or without the presence of systemic therapies according to historical cost comparisons, with an adjunctive cost-effectiveness ratio of $28,312-$59,554 per LYG.

CONCLUSIONS

MCA was associated with very low morbidity and local tumor recurrence rates for all anatomic sites, with apparent increased OS. Even as an adjunct to systemic therapies, MCA appeared cost-effective for palliation of oligometastatic RCC.

Cost comparison of nephron-sparing treatments for cT1a renal masses

OBJECTIVES

Treatment options for small renal tumors have evolved from radical nephrectomy (RN) to partial nephrectomy (PN), thermal ablation, or active surveillance. With the advancement of techniques, costs differences are unclear. The objective of this study is to compare the 6-month costs associated with nephron-sparing procedures for cT1a renal tumors.

MATERIALS AND METHODS

We performed a review of patients diagnosed with a solitary cT1a renal mass who underwent surgical treatment from June 2008 to May 2011. Open partial nephrectomy (OPN), robot-assisted partial nephrectomy (RLPN), laparoscopic radio-frequency ablation (LRFA), or computed tomography guided radio frequency ablation (CTRFA) was performed on 173 patients. Cost data were collected for surgical costs, associated hospital stay, and the 6-month postoperative period.

RESULTS

Patients underwent surgery, including 52 OPN, 48 RLPN, 44 LRFA, and 29 CTRFA. Median total costs associated were $17,018, $20,314, $13,965, and $6,475, for OPN, RLPN, LRFA, and CTRFA, respectively. When stratified by approach differences were noted for total cost (P < 0.001), operating room (OR) time (P < 0.001), surgical supply (P < 0.001), and room and board (P < 0.001) in univariable analysis. Multivariable linear regression (R(2) = 0.966) showed surgical approach (P = 0.007), length of stay (P < 0.001), and OR time (P < 0.001) to be significant predictors of total cost. However, tumor size (P = 0.175), and Charlson comorbidity index (P = 0.078) were not statistically significant.

CONCLUSIONS

Six-month cost of nephron-sparing surgery is lowest with radio frequency ablation (RFA) by either laparoscopic or computed tomography (CT)-guided approach compared to RLPN and OPN. As oncologic and safety outcomes improve and become comparable in all nephron-sparing surgery (NSS) approaches, cost of each procedure will start to play a stronger role in the clinical and healthcare policy setting.

The cost-effectiveness of immediate treatment, percutaneous biopsy and active surveillance for the diagnosis of the small solid renal mass: evidence from a Markov model

PURPOSE

The most effective diagnostic strategy for the very small, incidentally detected solid renal mass is uncertain. We assessed the cost-effectiveness of adding percutaneous biopsy or active surveillance to the diagnosis of a 2 cm or less solid renal mass.

MATERIALS AND METHODS

A Markov state transition model was developed to observe a hypothetical cohort of healthy 60-year-old men with an incidentally detected, 2 or less cm solid renal mass, comparing percutaneous biopsy, immediate treatment and active surveillance. The primary outcomes assessed were the incremental cost-effectiveness ratio measured by cost per life-year gained at a willingness to pay threshold of $50,000. Model results were assessed by sensitivity analysis.

RESULTS

Immediate treatment was the highest cost, most effective diagnostic strategy, providing the longest overall survival of 18.53 life-years. Active surveillance was the lowest cost, least effective diagnostic strategy. On cost-effectiveness analysis using a societal willingness to pay threshold of $50,000 active surveillance was the preferred choice at a $75,000 willingness to pay threshold while biopsy and treatment were acceptable ($56,644 and $70,149 per life-year, respectively). When analysis was adjusted for quality of life, biopsy dominated immediate treatment as the most cost-effective diagnostic strategy at $33,840 per quality adjusted life-year gained.

CONCLUSIONS

Percutaneous biopsy may have a greater role in optimizing the diagnosis of an incidentally detected, 2 cm or less solid renal mass.

Ablative therapies for renal tumors

Owing to an increased use of diagnostic imaging for evaluating patients with other abdominal conditions, incidentally discovered kidney masses now account for a majority of renal tumors. Renal ablative therapy is assuming a more important role in patients with borderline renal impairment. Renal ablation uses heat or cold to bring about cell death. Radiofrequency ablation and cryoablation are two such procedures, and 5-year results are now emerging from both modalities. Renal biopsy at the time of ablation is extremely important in order to establish tissue diagnosis. Real-time temperature monitoring at the time of radiofrequency ablation is very useful to ensure adequacy of ablation.

Percutaneous radiofrequency ablation of renal parenchyma: experimental study on the optimal temperature and the impact of vasoactive drugs

BACKGROUND AND PURPOSE

Radiofrequency (RF) is an efficient, inexpensive, safe, and friendly option for the management of small renal tumors. The objective was to evaluate the ideal temperature for renal cell destruction in dogs by RF and to verify whether the injection of vasoactive drugs, such as prostaglandin E1 and adrenaline, can help to improve the results, compared with "dry" RF ablation.

MATERIALS AND METHODS

The study was divided into three phases: Initially, 16 dogs of comparable weight underwent RF ablation of the renal parenchyma at temperatures of 80°C, 90°C, and 100°C. After that, seven other dogs received adrenaline (vasoconstrictor) and seven received prostaglandin E1 (vasodilator). Finally, the results from 14 animals were compared with those of the 16 (dry RF) dogs at the optimum temperature found. After 14 days, the animals underwent nephrectomy to evaluate the size of the lesions (width and depth), histology examination, and were then sacrificed.

RESULTS

There were no clinical or surgical complications in any of the dogs, and none died before the 14th day after the procedure. The optimum temperature was found to be 90°C. Prostaglandin E1 resulted in significantly larger lesions (in depth and width) than adrenaline, with lower impedance. Prostaglandin did not increase the lesions compared with dry RF. All the kidneys presented total coagulation necrosis, with no viable cells in the histologic analysis of the treated tissue.

CONCLUSION

In the ablation of renal cells by RF, prostaglandin produced larger lesions (in depth and width) than the same procedure using adrenaline, and its performance was similar to that of RF without injection of drugs.

[Process-oriented cost calculation in interventional radiology. A case study]

PURPOSE

Currently used costing methods such as cost centre accounting do not sufficiently reflect the process-based resource utilization in medicine. The goal of this study was to establish a process-oriented cost assessment of percutaneous radiofrequency (RF) ablation of liver and lung metastases.

MATERIAL AND METHODS

In each of 15 patients a detailed task analysis of the primary process of hepatic and pulmonary RF ablation was performed. Based on these data a dedicated cost calculation model was developed for each primary process. The costs of each process were computed and compared with the revenue for in-patients according to the German diagnosis-related groups (DRG) system 2010.

RESULTS

The RF ablation of liver metastases in patients without relevant comorbidities and a low patient complexity level results in a loss of EUR 588.44, whereas the treatment of patients with a higher complexity level yields an acceptable profit. The treatment of pulmonary metastases is profitable even in cases of additional expenses due to complications.

CONCLUSION

Process-oriented costing provides relevant information that is needed for understanding the economic impact of treatment decisions. It is well suited as a starting point for economically driven process optimization and reengineering. Under the terms of the German DRG 2010 system percutaneous RF ablation of lung metastases is economically reasonable, while RF ablation of liver metastases in cases of low patient complexity levels does not cover the costs.

Economic burden of renal cell carcinoma: Part I--an updated review

The economic burden of renal cell carcinoma (RCC) came into sharp focus when the UK National Institute for Health and Clinical Excellence (NICE) denied coverage (later reversed) of sunitinib for metastatic RCC. In the first of two articles that provide updated reviews and analyses of the economic burden of RCC, we conducted an updated literature review of RCC-related economic studies. We performed a literature search of PubMed, EMBASE and the Cochrane Library for English-language studies published from 1 January 2000 to 15 June 2010. We also performed a separate search for related studies in the Health Technology Assessment (HTA) reports published by the National Institute for Health Research HTA Programme in the UK. Identified articles were classified into three categories: cost studies, cost-effectiveness/cost-utility studies and cost-of-illness studies. All cost estimates were normalized to $US, year 2009 values. We identified 20 articles, including six cost, six cost-utility and eight cost-of-illness studies. In general, the studies found new surgical techniques, such as laparoscopic partial nephrectomy, to be potentially cost saving (in the range of $US181-5842). Targeted agents, such as bevacizumab, sunitinib, sorafenib and temsirolimus, were associated with higher lifetime costs ($US8537-72 254) and were not always considered to be cost effective by authors of the cost-effectiveness studies included in this review (incremental cost-effectiveness ratio [ICER]: $US49 959-272 418 per QALY). The literature reported annual estimates of the US economic burden of RCC between $US0.60 billion and $US5.19 billion, with per-patient costs of $US16 488-43 805. RCC is associated with substantial economic burden, although the estimates are wide ranging. Comparisons of the estimates across studies were hindered by variations in study methodology, choice of database and the associated timeframe, and limitations inherent to each database. More research is needed to assess the quality of the economic studies of RCC and to understand why the estimated costs differ across studies.

Cost-effectiveness analysis of nephron sparing options for the management of small renal masses

PURPOSE

A recent increase in the detection of contrast enhancing renal masses 4 cm or smaller suspicious for malignancy has led to the widespread use of nephron sparing options. Limited data exist to help clinicians decide which of these competing nephron sparing therapies is most appropriate. We performed a cost-effectiveness analysis to evaluate the relative clinical and economic merits of commonly available nephron sparing strategies for small renal masses.

MATERIALS AND METHODS

We developed a decision analytic Markov model estimating the costs and health outcomes of treating a healthy 65-year-old patient with an asymptomatic unilateral small renal mass using competing nephron sparing options of immediate intervention (ie open and laparoscopic partial nephrectomy as well as laparoscopic and percutaneous ablation), active surveillance with possible delayed intervention and nonsurgical management with observation. Benefits were measured in quality adjusted life-years. We used a societal perspective, lifetime horizon and willingness to pay threshold of $50,000 per quality adjusted life-year gained. Model results were assessed with sensitivity analyses.

RESULTS

In the base case scenario the least costly option was observation and the optimal option was immediate laparoscopic partial nephrectomy, which had an incremental cost-effectiveness ratio of $36,645 per quality adjusted life-year gained compared to surveillance with possible delayed percutaneous ablation. Results were sensitive to age at diagnosis, health status and tumor size.

CONCLUSIONS

Immediate laparoscopic partial nephrectomy is the preferred nephron sparing option for healthy patients younger than 74 years old with a small renal mass. Surveillance with possible delayed percutaneous ablation is a cost-effective alternative for patients with advanced age or significant comorbidities. Observation maximizes quality adjusted life-years in patients who are poor surgical candidates or with limited life expectancy (less than 3 years).

Effectiveness of ultrasound-guided radiofrequency ablation in the treatment of 36 renal cell carcinoma tumours compared with published results of using computed tomography guidance

This study aimed to analyse the outcomes of ultrasound (US) guided radiofrequency ablation (RFA) in patients with renal lesions and to compare our outcomes with published results of ablations carried out when using computed tomography (CT) guidance. This retrospective study evaluated RFA of 36 renal tumours in 32 patients (M = 21, F = 11). The mean patient age was 70 years (range, 39-89 years). Ablations were performed by using either multi-tined applicators or cooled and/or cluster applicators under US guidance. Applicator size varied from 2-5 cm, depending on the size of the index tumour. Conscious sedation was administered by an anesthetist. Follow-up imaging by using contrast-enhanced CT was performed 1, 3, 6, and 12 months after RFA, and yearly thereafter. The mean tumour follow-up time was 12 months (range, 1-35 months). The mean tumour size was 2.7 cm (range, 1-5 cm). Primary effectiveness was achieved in 31 cases (86.1%), with patients in 5 cases (11.1%) demonstrating residual disease. Three patients had repeated sessions, which were technically successful. The remaining 2 patients were not re-treated because of patient comorbidities. As a result, secondary effectiveness was achieved in 34 patients (94.4%). In 1 patient, a new lesion developed in the same kidney but remote from the 2 prior areas of treatment. Hydrodissection was performed in 3 patients (8.3%), manipulation or electrode repositioning in 11 patients (30.6%), and ureteric cooling in 1 patient (2.8%). Minor and major complications occurred in 3 (8.3%) and 3 (8.3%) patients, respectively. Correlation coefficients were calculated for distance from skin to tumour and risk of complication as well as compared with primary and secondary effectiveness. This study demonstrates that US-guided RFA is an effective treatment for renal lesions, with rates of effectiveness and complication rates comparable with published CT-guided RFA results.

Radiofrequency ablation: a minimally invasive approach in kidney tumor management

The management and diagnosis of renal tumors have changed significantly over the last decade. Due to advances in imaging techniques, more than 50% of kidney tumors are discovered incidentally and many of them represent an early stage lesion. This has stimulated the development of nephron-sparing surgery and of the minimally invasive treatment options including ablative techniques, i.e., radiofrequency ablation (RFA) and cryoablation. The objective of the minimally invasive approach is to preserve the renal function and to lower the perioperative morbidity. RFA involves inducing the coagulative necrosis of tumor tissue. Being probably one of the least invasive procedures in kidney tumor management, RFA may be performed percutaneously under ultrasound (US), computed tomography (CT) or magnetic resonance (MR) guidance. Most of the studies show that the RFA procedure is efficient, safe and has a low complication rate. Due to the still limited data on the oncological outcome of RFA, the indication for this intervention remains limited to selected patients with small organ-confined renal tumors and contraindication to surgery or who have a solitary kidney. The aim of our study is to review the literature on RFA of kidney tumors.