Cost effectiveness analysis of radiofrequency ablation (RFA) versus stereotactic body radiotherapy (SBRT) for early stage renal cell carcinoma (RCC)

Comparative efficacy and safety of ablative therapies in the management of primary localised renal cell carcinoma: a systematic review and meta-analysis

BACKGROUND

Non-invasive and minimally invasive ablative treatments, including stereotactic body radiotherapy (SBRT), radiofrequency ablation, microwave ablation, and cryoablation, have emerged as key treatment options for managing renal cell carcinoma, especially for patients who are unsuitable for surgery. We aimed to compare the clinical efficacy and safety of these emerging treatment methods in patients with localised renal cell carcinoma.

METHODS

In this systematic review and meta-analysis, we searched PubMed (MEDLINE), Embase, and the Cochrane Library for publications between Jan 1, 2000, and March 1, 2024. Eligible articles were observational studies and randomised controlled trials including at least five adult patients (age ≥18 years) with primary and localised renal cell carcinoma treated with SBRT, radiofrequency ablation, microwave ablation, or cryoablation and that reported on local control outcomes. Two reviewers independently screened titles and abstracts and then full texts of eligible studies were independently evaluated by the same reviewers, with disagreements resolved via discussion or consultation with a third reviewer. Summary estimates were extracted from published reports manually using a standardised data extraction form. The primary endpoint was local control rate at 1 year, 2 years, and 5 years after start of treatment. A meta-analysis was conducted using a DerSimonian and Laird model to summarise local control rates. Publication bias was evaluated using funnel plots and Egger's test. We also recorded the frequency and severity of adverse events after treatment on the basis of the Common Terminology Criteria for Adverse Events (version 5.0) and Clavien-Dindo complication index. The study protocol was prospectively registered with PROSPERO, CRD42024511840.

FINDINGS

We identified 6668 records, of which 330 were assessed via full-text review, and 133 were included in our systematic review and meta-analysis. The eligible studies included data for 8910 patients (mean age 67·9 years [SD 7·3], 2518 [31·4%] of 8018 patients with available data were female and 5500 [68·6%] were male). Local control rates for SBRT were 99% (95% CI 97-100; I2=6%) at 1 year, 97% (95-99; I2=0%) at 2 years, and 95% (89-98; I2=42%) at 5 years; for radiofrequency ablation were 96% (94-98; I2=73%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 92% (88-96; I2=78%) at 5 years; for microwave ablation were 97% (95-99; I2=74%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 86% (75-94; I2=66%) at 5 years; and for cryoablation were 95% (93-96; I2=61%) at 1 year, 94% (91-96; I2=69%) at 2 years, and 90% (87-93; I2=74%) at 5 years. The proportion of patients who reported grade 3-4 adverse events was 3% (121 of 3726) after cryoablation, 2% (39 of 2503) after radiofrequency ablation, 1% (22 of 2069) after microwave ablation, and 2% (11 of 612) after SBRT. Risk of bias was moderate in most studies (70 [53%] of 133) and no publication bias was observed.

INTERPRETATION

All investigated ablative methods continue to represent effective treatment choices in renal cell carcinoma, and these findings support multi-disciplinary discussions of these treatment methods, along with surgery and surveillance, to individualise treatment decisions in these patients. Future research should aim to conduct randomised controlled trials across larger patient populations to further elucidate the long-term oncological and survival outcomes associated with these treatments.

FUNDING

None.

Stereotactic Body Therapy for Urologic Cancers-What the Urologist Needs to Know

BACKGROUND

stereotactic ablative body radiotherapy (SABR) is a disruptive radiation therapy technique which is increasingly used for the treatment of urologic cancers. The aim of this narrative review is to provide an overview on the current landscape of SABR in urologic cancers and highlight advancements on the horizon.

METHODS

a narrative review of the contemporary role of SABR in urologic cancers is conducted.

RESULTS

in localised prostate cancer, SABR boasts excellent tumour control and biochemical control, with acceptable GU and GI toxicity. Its comparison to laparoscopic radical prostatectomy is currently ongoing. SABR appears to be practical for metastasis-directed therapy in metastatic prostate cancer, with good local control and a low toxicity profile, either alone or in combination with ADT. In localised RCC, SABR offers adequate local control with a modest impact on renal function in patients unfit for surgical management. Its role in metastatic RCC is much more established, where it has been shown to be superior to conventional radiotherapy. Emerging evidence suggests that SABR has a role in delaying systemic therapy whilst maintaining QOL and overall survival. Intriguingly, in metastatic prostate cancer and metastatic RCC, SABR results in a cytoreductive and immunomodulatory 'abscopal effect', a focus of current investigations.

CONCLUSIONS

SABR has emerged as a safe, effective, and feasible treatment for urologic cancers. Urologists should be aware of its increasing use in localised prostate cancer and metastatic RCC, with good oncological outcomes combined with acceptable toxicity. In addition, SABR holds promise for both metastatic prostate cancer and localised RCC treatment in terms of toxicity and oncological outcomes.

Scoping Review of Economic Analyses of Rare Kidney Diseases

Introduction

Rare kidney diseases (RKDs) place a substantial economic burden on patients and health systems, the extent of which is unknown and may be systematically underestimated by health economic techniques. We aimed to investigate the economic burden and cost-effectiveness evidence base for RKDs.

Methods

We conducted a systematic scoping review to identify economic evaluations, health technology assessments, and cost-of-illness studies relating to RKDs, published since 2012.

Results

A total of 161 published studies, including 66 cost-of-illness studies and 95 economic evaluations; 72 grey literature reports were also included. Most published literature originated from high-income nations, particularly the USA (81 studies), and focused on a handful of diseases, notably renal cell carcinomas (70) and systemic lupus erythematosus (36). Limited evidence was identified from lower-income settings and there were few studies of genetic conditions, which make up most RKDs. Some studies demonstrated the cost-effectiveness of existing treatments; however, there were limited considerations of broader economic impacts on patients that may be important to those with RKDs. Included health technology assessments highlighted difficulties in obtaining high-quality clinical evidence for treatments in very small patient populations, and often considered equity issues and other patient impacts qualitatively alongside clinical and economic evidence in their recommendations.

Conclusion

We found large gaps in the economic evidence base for RKDs and limited adaptation of methods to account for the uniqueness of these diseases. There may be significant scope for innovation in building an investment case for RKD treatments, as well as in decision-making processes to inform investment decisions.

Economic evaluation of stereotactic radiotherapy and stereotactic radiosurgery technologies in the treatment of cancers: a systematic review

INTRODUCTION

This systematic review study investigated the cost-effectiveness of stereotactic radiotherapy (SRT) and stereotactic radiosurgery (SRS) for treatment of various types of cancers.

METHODS

PubMed, Scopus, and Web of Science were searched from 30 December 1990 to 1 January 2023. The entered studies were screened in accordance with the inclusion criteria. The inclusion criteria encompassed all types of economic evaluation studies that investigated SRT/SRS technologies in the treatment of various cancers.

RESULTS

A total of 47 articles were included in the review. The findings suggest that the use of Linear accelerator technology for the treatment of lung cancer (8 out of 12 studies) and prostate cancer (4 out of 5 studies) was a cost-effective strategy. Linear accelerator was found to be cost-effective in the treatment of liver metastases and liver cancer (2 out of 5 studies). All of the included studies that used Gamma Knife technology in brain metastases reported Gamma-Knife was a cost-effective treatment. Furthermore, in the treatment of prostate and liver cancer, proton therapy was identified as a cost-effective option than other treatments.

CONCLUSIONS

This study confirms that SRT/SRS is a cost-effective procedure for the treatment of various types of cancers. Therefore, it is recommended to use SRT/SRS technology for optimal use of resources.

Evaluation of Volumetric Response Assessment From SABR for Renal Cell Carcinoma

PURPOSE

SABR is increasingly used to treat renal cell carcinoma (RCC). However, the optimal method to assess treatment response is unclear. We aimed to quantify changes in both volume and maximum linear size of tumors after SABR and evaluate the utility of the 2 approaches in treatment response assessment.

METHODS AND MATERIALS

We retrospectively studied patients with RCC treated with SABR at our institution between 2013 and 2020. All available follow-up computed tomography scans were aligned, and tumors were contoured on all scans. Volume and maximum linear size were measured at each follow-up, relative to these measurements at the time of computed tomography simulation.

RESULTS

Twenty-four patients with 25 tumors were included. Median follow-up was 32 months (range, 16-67). Nineteen tumors (76%) had 30% volumetric response at a median time of 7 months after SABR, and 12 tumors (48%) had 30% decrease in maximum linear size at a median time of 16 months. Eighteen tumors (72%) decreased in volume on first follow-up scan and continued to shrink, and 5 tumors (20%) displayed transient growth after SABR (average 24% increase in volume). Compared with T1a tumors, T1b or larger tumors were more likely to have transient growth (8% vs 33%; P = .16) and had higher average relative volume 24 months after SABR (0.47 vs 0.8; P = .022).

CONCLUSIONS

Volume measurement results in more pronounced and earlier change compared with linear size measurement when assessing response to SABR. These findings may provide guidance when assessing treatment response for patients with RCC treated with SABR.

5-year outcomes after stereotactic ablative body radiotherapy for primary renal cell carcinoma: an individual patient data meta-analysis from IROCK (the International Radiosurgery Consortium of the Kidney)

BACKGROUND

Stereotactic ablative body radiotherapy (SABR) is a non-invasive treatment option for primary renal cell carcinoma, for which long-term data are awaited. The primary aim of this study was to report on long-term efficacy and safety of SABR for localised renal cell carcinoma.

METHODS

This study was an individual patient data meta-analysis, for which patients undergoing SABR for primary renal cell carcinoma across 12 institutions in five countries (Australia, Canada, Germany, Japan, and the USA) were eligible. Eligible patients had at least 2 years of follow-up, were aged 18 years or older, had any performance status, and had no previous local therapy. Patients with metastatic renal cell carcinoma or upper-tract urothelial carcinoma were excluded. SABR was delivered as a single or multiple fractions of greater than 5 Gy. The primary endpoint was investigator-assessed local failure per the Response Evaluation Criteria in Solid Tumours version 1.1, and was evaluated using cumulative incidence functions.

FINDINGS

190 patients received SABR between March 23, 2007, and Sept 20, 2018. Single-fraction SABR was delivered in 81 (43%) patients and multifraction SABR was delivered in 109 (57%) patients. Median follow-up was 5·0 years (IQR 3·4-6·8). 139 (73%) patients were men, and 51 (27%) were women. Median age was 73·6 years (IQR 66·2-82·0). Median tumour diameter was 4·0 cm (IQR 2·8-4·9). 96 (75%) of 128 patients with available operability details were deemed inoperable by the referring urologist. 56 (29%) of 190 patients had a solitary kidney. Median baseline estimated glomerular filtration rate (eGFR) was 60·0 mL/min per 1·73 m2 (IQR 42·0-76·0) and decreased by 14·2 mL/min per 1·73 m2 (IQR 5·4-22·5) by 5 years post-SABR. Seven (4%) patients required dialysis post-SABR. The cumulative incidence of local failure at 5 years was 5·5% (95% CI 2·8-9·5) overall, with single-fraction SABR yielding fewer local failures than multifraction (Gray's p=0·020). There were no grade 3 toxic effects or treatment-related deaths. One (1%) patient developed an acute grade 4 duodenal ulcer and late grade 4 gastritis.

INTERPRETATION

SABR is effective and safe in the long term for patients with primary renal cell carcinoma. Single-fraction SABR might yield less local failure than multifraction, but further evidence from randomised trials is needed to elucidate optimal treatment schedules. These mature data lend further support for renal SABR as a treatment option for patients unwilling or unfit to undergo surgery.

FUNDING

None.

Stereotactic Body Radiotherapy for Renal Cell Carcinoma in Patients with Von Hippel-Lindau Disease-Results of a Prospective Trial

Von Hippel-Lindau disease (VHL) is a hereditary disorder associated with malignant tumors including clear cell renal cell carcinoma (ccRCC). Partial nephrectomy is complicated by multilocular tumor occurrence and a high recurrence rate. The aim of this study was to evaluate the potential of stereotactic body radiotherapy (SBRT) as an alternative treatment approach in VHL patients with multiple ccRCC. Patients with VHL and a diagnosis of ccRCC were enrolled. SBRT was conducted using five fractions of 10 Gy or eight fractions of 7.5 Gy. The primary endpoint was local control (LC). Secondary endpoints included alteration of renal function and adverse events. Seven patients with a total of eight treated lesions were enrolled. Median age was 44 years. Five patients exhibited multiple bilateral kidney cysts in addition to ccRCC. Three patients underwent at least one partial nephrectomy in the past. After a median follow-up of 43 months, 2-year LC was 100%, while 2-year CSS, 2-year PFS and 2-year OS was 100%, 85.7% and 85.7%, respectively. SBRT was very well tolerated with no acute or chronic toxicities grade ≥ 2. Mean estimated glomerular filtration rate (eGFR) at baseline was 83.7 ± 13.0 mL/min/1.73 m2, which decreased to 76.6 ± 8.0 mL/min/1.73 m2 after 1 year. Although the sample size was small, SBRT resulted in an excellent LC rate and was very well tolerated with preservation of kidney function in patients with multiple renal lesions and cysts.