Comprehensive Management of Renal Masses in Solitary Kidneys

Salvage stereotactic ablative body radiotherapy after thermal ablation of primary kidney cancer

OBJECTIVE

To evaluate the effectiveness and safety of salvage stereotactic ablative body radiotherapy (SABR) for recurrent renal cell carcinoma (RCC) after thermal ablation (TA).

MATERIALS AND METHODS

This study was a multi-institutional retrospective analysis of patients with recurrent RCC following TA who received SABR between 2016 and 2020. The primary study outcome was freedom from local failure, evaluated radiographically based on Response Evaluation Criteria in Solid Tumours (RECIST) v1.1. Distant failure, cancer-specific survival (CSS), overall survival (OS), treatment-related toxicity and renal function changes following SABR were the secondary outcomes. The Kaplan-Meier method was used to estimate freedom from local and distant failure, CSS and OS.

RESULTS

Seventeen patients with 18 biopsy-confirmed RCCs were included, with a median (interquartile range [IQR]) age at time of SABR of 75.2 (72.6-68.7) years, a median (IQR) tumour size of 3.5 (1.9-4.1) cm and follow-up (reverse Kaplan-Meier method) of 3.36 (95% confidence interval [CI] 1.6-4.1) years. Six of the 17 patients had a solitary kidney. Five patients had failed repeat TA prior to SABR. The median (IQR) time from TA procedure to SABR was 3.03 (1.5-5.1) years. No patient experienced local progression, with a local control rate of 100%. Four patients, two with baseline metastatic disease, experienced distant progression. The distant progression-free survival, CSS and OS at 3 years were 72.1% (95% CI 51.9%-100%), 92.3% (95% CI 78.9%-100%) and 82.1% (95% CI 62.1%-100%), respectively. The median (IQR) glomerular filtration rate before SABR was 58 (40-71) mL/min, and at last follow-up, it was 48 (33-57) mL/min. No patient experienced grade 3+ toxicity or went on to develop end-stage renal disease.

CONCLUSION

The results showed that SABR appears to be an effective and safe salvage strategy in patients with recurrent RCC following TA.

Long-term Renal Function Outcomes After Stereotactic Ablative Body Radiotherapy for Primary Renal Cell Carcinoma Including Patients with a Solitary Kidney: A Report from the International Radiosurgery Oncology Consortium of the Kidney

BACKGROUND AND OBJECTIVE

Renal function preservation is particularly important following nonoperative treatment of localized renal cell carcinoma (RCC) since patients are often older with medical comorbidities. Our objective was to report long-term renal function outcomes after stereotactic ablative radiotherapy (SABR) including patients with a solitary kidney.

METHODS

Patients with primary RCC treated with SABR with ≥2 yr of follow-up at 12 International Radiosurgery Consortium for Kidney institutions were included. Renal function was measured by estimated glomerular filtration rate (eGFR).

KEY FINDINGS AND LIMITATIONS

In total, 190 patients (56 with a solitary kidney) underwent SABR and were followed for a median of 5.0 yr (interquartile range [IQR]: 3.4-6.8). In patients with a solitary kidney versus bilateral kidneys, pre-SABR eGFR (mean [standard deviation]) was 61.1 (23.2) versus 58.0 (22.3) ml/min (p = 0.32) and the median tumor size was 3.65 cm (IQR: 2.59-4.50 cm) versus 4.00 cm (IQR: 3.00-5.00 cm; p = 0.026). At 5 yr after SABR, eGFR decreased by -14.5 (7.6) and -13.3 (15.9) ml/min (p = 0.67), respectively, and there were similar rates of post-SABR dialysis (3.6% [n = 2/56] vs 3.7% [n = 5/134]). A multivariable analysis demonstrated that increasing tumor size (odds ratio [OR] per 1 cm: 1.57; 95% confidence interval [CI]: 1.14-2.16, p = 0.0055) and baseline eGFR (OR per 10 ml/min: 1.30; 95% CI: 1.02-1.66, p = 0.034) were associated with an eGFR decline of ≥15 ml/min at 1 yr.

CONCLUSIONS AND CLINICAL IMPLICATIONS

With long-term follow-up after SABR, kidney function decline remains moderate, with no observed difference between patients with a solitary kidney and bilateral kidneys. Tumor size and baseline eGFR are dominant factors predictive of long-term renal function decline.

PATIENT SUMMARY

With long-term follow-up, stereotactic ablative radiotherapy (SABR) yields moderate long-term renal function decline and low dialysis rates even in patients with a solitary kidney. SABR thus represents a promising noninvasive, nephron-sparing option for patients with localized renal cell carcinoma.

Combining Transarterial Embolization and Percutaneous Cryoablation for Early-Stage Renal Cell Carcinoma: Embolization Materials and Impacts of Tumor Size

BACKGROUND/OBJECTIVES

Our aim was to compare the complication rates of different embolization materials (absolute ethanol and gelatin sponges) used for combined transarterial embolization (TAE) and to investigate the impact of tumor size on operative time and cryoneedle use during percutaneous cryoablation (PCA).

METHODS

We treated 27 patients (9 women and 18 men; mean age, 74 years) with 28 early-stage (T1a) renal cell carcinoma (RCC) lesions using combined TAE and PCA between September 2018 and January 2021. During TAE, 15 lesions in 14 patients were embolized using mixed absolute ethanol and iodized oil. The remaining 13 lesions (in 13 patients) were embolized using a gelatin sponge followed by iodized oil. The PCA was performed within 3 to 21 days of the TAE. We compared complications between the TAE subgroups (i.e., absolute ethanol and gelatin sponge) and assessed potential correlations between tumor size and the operative time of the PCA.

RESULTS

All patients were successfully treated by combined TAE-PCA. Local control was achieved for all patients (monitoring period, 1-48 months; median, 28 months). Although the effect of TAE did not differ between subgroups, a significantly higher number of patients in the absolute ethanol group experienced intraprocedural pain than in the gelatin sponge group (p < 0.05). The operative time of the PCA was significantly correlated with the size of the RCC lesion (p < 0.01). The number of cryoneedles used for the PCA was also correlated with the size of the RCC lesion (p < 0.0001).

CONCLUSIONS

For TAE prior to PCA for early-stage RCC, gelatin sponges can replace absolute ethanol to reduce intraprocedural pain. Tumor size correlates with operative time and the number of cryoneedles needed for PCA, which suggests the total medical cost for PCA therefore varies based on the tumor's size.

Correlation of Ablation Volume with Renal Function Loss after Cryoablation in Solitary Functioning Kidneys

PURPOSE

To determine the degree of renal function deterioration after renal cryoablation in patients with a solitary functioning kidney on the basis of ablation volume.

MATERIALS AND METHODS

Over a 15-year period, 81 percutaneous cryoablations were performed in solitary functioning kidneys. After exclusion of patients with baseline end-stage renal disease (ESRD) and insufficient follow-up, analysis was performed on 65 procedures in 52 patients (40 men; mean age, 63.5 years). The postcryoablation renal function was based on the lowest serum creatinine within 6 months after procedure. Renal function change was defined as percentage glomerular filtration rate (GFR) change. Volumetric analysis was performed on the target lesion, renal parenchyma, and ablation zone.

RESULTS

The median tumor diameter was 2.0 cm (range, 0.8-4.7 cm). The median baseline GFR decreased from 56.4 mL/min/1.73 m2 (range, 17.5-89.7 mL/min/1.73 m2) to 46.9 mL/min/1.73 m2 (range, 16.5-89.7 mL/min/1.73 m2) at median of 95 days (P < .001), equating to a -7.9% median renal function change (range, -45.0% to +30.7%). All patients had Stage 2 or worse chronic kidney disease, and baseline function did not correlate with renal function change. The median volume of ablated parenchyma was 19.7 mL (range, 2.4-87.3 mL), equating to 8.1% (range, 0.7%-37.2%) of total parenchyma. The volume of parenchymal volume ablated correlated significantly with renal function loss, whereas age, hypertension, and diabetes mellitus did not. No patient developed ESRD within 1 year after cryoablation.

CONCLUSIONS

Cryoablation in solitary functioning kidneys resulted in a modest reduction in renal function, even in patients with chronic kidney disease and ablations of up to 20% of renal parenchymal volume.

Parenchymal volume preservation during partial nephrectomy: improved methodology to assess impact and predictive factors

OBJECTIVE

To rigorously evaluate the impact of the percentage of parenchymal volume preserved (PPVP) and how well the preserved parenchyma recovers from ischaemia (Recischaemia) on functional outcomes after partial nephrectomy (PN) using an accurate and objective software-based methodology for estimating parenchymal volumes and split renal function (SRF). A secondary objective was to assess potential predictors of the PPVP.

PATIENTS AND METHODS

A total of 894 PN patients with available studies (2011-2014) were evaluated. The PPVP was measured from cross-sectional imaging at ≤3 months before and 3-12 months after PN using semi-automated software. Pearson correlation evaluated relationships between continuous variables. Multivariable linear regression evaluated predictors of ipsilateral glomerular filtration rate (GFR) preserved and the PPVP. Relative-importance analysis was used to evaluate the impact of the PPVP on ipsilateral GFR preserved. Recischaemia was defined as the percentage of ipsilateral GFR preserved normalised by the PPVP.

RESULTS

The median tumour size and R.E.N.A.L. nephrometry score were 3.4 cm and 7, respectively. In all, 49 patients (5.5%) had a solitary kidney. In all, 538 (60%)/251 (28%)/104 (12%) patients were managed with warm/cold/zero ischaemia, respectively. The median pre/post ipsilateral GFRs were 40/31 mL/min/1.73 m2, and the median (interquartile range [IQR]) percentage of ipsilateral GFR preserved was 80% (71-88%). The median pre/post ipsilateral parenchymal volumes were 181/149 mL, and the median (IQR) PPVP was 84% (76-92%). In all, 330 patients (37%) had a PPVP of <80%, while only 34 (4%) had a Recischaemia of <80%. The percentage of ipsilateral GFR preserved correlated strongly with the PPVP (r = 0.83, P < 0.01) and loss of parenchymal volume accounted for 80% of the loss of ipsilateral GFR. Multivariable analysis confirmed that the PPVP was the strongest predictor of ipsilateral GFR preserved. Greater tumour size and endophytic and nearness properties of the R.E.N.A.L. nephrometry score were associated with a reduced PPVP (all P ≤ 0.01). Solitary kidney and cold ischaemia were associated with an increased PPVP (all P < 0.05).

CONCLUSIONS

A reduced PPVP predominates regarding functional decline after PN, although a low Recischaemia can also contribute. Tumour-related factors strongly influence the PPVP, while surgical efforts can improve the PPVP as observed for patients with solitary kidneys.

Thermal Ablation Versus Partial Nephrectomy for cT1 Renal Mass in a Solitary Kidney: A Matched Cohort Comparative Analysis

BACKGROUND

Nephron-sparing approaches are preferred for renal mass in a solitary kidney (RMSK), with partial nephrectomy (PN) generally prioritized. Thermal ablation (TA) also is an option for small renal masses in this setting; however, comparative functional/survival outcomes are not well-defined.

METHODS

A retrospective study of 504 patients (1975-2022) with cT1 RMSK managed with PN (n = 409)/TA (n = 95) with necessary data for analysis was performed. Propensity score was used for matching patients, including age, preoperative glomerular filtration rate (GFR), tumor diameter, R.E.N.A.L. ((R)adius (tumor size as maximal diameter), (E)xophytic/endophytic properties of tumor, (N)earness of tumor deepest portion to collecting system or sinus, (A)nterior (a)/posterior (p) descriptor, and (L)ocation relative to polar lines), and comorbidities. Functional outcomes were compared, and Kaplan-Meier was used to analyze survival.

RESULTS

The matched cohort included 132 patients (TA = 66/PN = 66), with median tumor diameter of 2.4 cm, R.E.N.A.L. of 6, and preoperative GFR of 52 ml/min/1.73 m2. Acute kidney injury occurred in 11%/61% in the TA/PN cohorts, respectively (p < 0.01). After recovery, median GFR preserved was 89%/83% for TA/PN, respectively (p = 0.02), and 5-year dialysis-free survival was 96% in both cohorts. Median follow-up was 53 months. Five-year recurrence-free survival (RFS) was 62%/86% in the TA/PN cohorts, respectively (p < 0.01). Five-year local recurrence (LR)-free survival was 74%/95% in the TA/PN cohorts, respectively (p < 0.01). Five-year cancer-specific survival (CSS) was 96%/98% in the TA/PN cohorts, respectively (p = 0.7). Local recurrence was observed in nine of 36 (25%) and five of 30 (17%) patients managed with laparoscopic versus percutaneous TA, respectively. For TA with LR (n = 14), nine patients presented with multifocality and/or cT1b tumors. Twelve LR were managed with salvage TA, and seven remained cancer-free, while five developed systemic recurrence, three with concomitant LR.

CONCLUSIONS

Functional outcomes for TA for RMSK were improved compared with PN. Local recurrence was more common after TA and often was associated with the laparoscopic approach, multifocality, and large tumor size. Improved patient selection and greater experience with TA should improve outcomes. Salvage of LR was not always possible. Partial nephrectomy remains the reference standard for RMSK.

Incidence, risk factors, and significance of 20% decrease from new baseline estimated glomerular filtration rate after radical and partial nephrectomy within 2 years

OBJECTIVES

To evaluate the incidence and risk factors of a 20% decrease from new baseline (NB)-estimated glomerular filtration rate (eGFR) within 2 years after radical nephrectomy (RN) and partial nephrectomy (PN) and to examine the difference in the incidence of end-stage renal disease (ESRD) with or without the 20% decrease.

METHODS

This retrospective study included 238 patients undergoing RN and 369 undergoing PN for cT1a-cT3a renal cancer. The incidence of a 20% decrease from NB-eGFR within 2 years after RN/PN was examined and its potential risk factors including surgery type were assessed by multivariate logistic regression analysis. The development of ESRD was analyzed as an endpoint and its incidence was compared according to the presence or absence of the 20% decrease from NB-eGFR within 2 years.

RESULTS

Overall, the 20% decrease from NB-eGFR within 2 years was observed in 37 patients (6.1%), including 10 (4.2%) and 27 (7.3%) after RN and PN, respectively (p = 0.117). Diabetes mellitus, proteinuria, and perioperative complications were shown to be independent risk factors for the 20% decrease from NB-eGFR, while surgery type was not. During the median follow-up of 65 months, the ESRD-free survival rate at 6 years was 75.5% and 99.6% in patients with and without the 20% decrease from NB-eGFR, respectively (p < 0.001), while no significant difference was observed between patients undergoing RN and PN (98.1% and 98.7%, p = 0.561).

CONCLUSIONS

Because the incidence of ESRD after the 20% decrease from NB-eGFR within 2 years was as high as 24.5% at 6 years, these patients should be followed with utmost care.

Functional recovery after partial nephrectomy in a solitary kidney

OBJECTIVES

Partial nephrectomy (PN) is the reference standard for renal mass in a solitary kidney (RMSK), although factors determining functional recovery in this setting remain poorly defined.

PATIENTS/METHODS

Single center, retrospective analysis of 841 RMSK patients (1975-2022) managed with PN with functional data, including 361/435/45 with cold/warm/zero ischemia, respectively. A total of 155 of these patients also had necessary studies for detailed analysis of parenchymal volume preserved. Acute kidney injury (AKI) was classified by RIFLE (Risk/Injury/Failure/Loss/Endstage). Recovery-from-ischemia (Rec-Ischemia) was defined as glomerular filtration rate (GFR) saved normalized by parenchymal volume saved. Logistic regression identified predictive factors for AKI and predictors of Rec-Ischemia were analyzed by multivariable linear regression.

RESULTS

Overall, median preoperative GFR was 56.7 ml/min/1.73m2 and new-baseline and 5-year GFRs were 43.1 and 44.5 ml/min/1.73m2, respectively. Median follow-up was 55 months; 5-year dialysis-free survival was 97%. In the detailed analysis cohort, a primary focus of this study, median warm (n = 70)/cold (n = 85) ischemia times were 25/34 minutes, respectively; and median preoperative, new-baseline and 5-year GFRs were 57.8, 45.0, and 41.7 ml/min/1.73m2, respectively. Functional recovery correlated strongly with parenchymal volume preserved (r = 0.84, p < 0.001). Parenchymal volume loss accounted for 69% of the total median GFR decline associated with PN, leaving only 3 to 4 ml/min/1.73m2 attributed to ischemia and other factors. AKI occurred in 52% of patients and the only independent predictor of AKI was ischemia time. Independent predictors of reduced Rec-Ischemia were increased age, warm ischemia, and AKI.

CONCLUSION

The main determinant of functional recovery after PN in RMSK is parenchymal volume preservation. Type/duration of ischemia, AKI, and age also correlated, although altogether their contributions were less impactful. Our findings suggest multiple opportunities for optimizing functional outcomes although preservation of parenchymal volume remains predominant. Long-term function generally remains stable with dialysis only occasionally required.

Perioperative, functional, and oncological outcomes after cryoablation or partial nephrectomy for small renal masses in solitary kidneys: a systematic review and meta-analysis

AIM

This study aims to compare the perioperative, functional, and oncological outcomes of cryoablation (CA) and partial nephrectomy (PN) for managing small renal masses in patients with solitary kidneys. The study seeks to assess the efficacy and safety of both interventions, evaluating their impact on kidney function and their ability to mitigate cancer recurrence.

METHODS

Searches were systematically conducted on PubMed, Scopus, EMBASE, SinoMed, and Google Scholar, identifying seven observational studies. Statistical analysis was performed using Stata v.12.0 and Review Manager version 5.2. Results for dichotomous variables are expressed using odds ratios, and weighted mean differences are used for continuous variables.

RESULTS

Our findings revealed that patients undergoing CA experienced significantly shorter operative time (p < 0.0001), reduced estimated blood loss (p < 0.00001), a shorter length of stay (p = 0.0001), and fewer postoperative complications (p = 0.02) compared to those undergoing PN. Although the CA group exhibited a lower transfusion rate (p = 0.69) compared with the PN group, the difference was not statistically significant. The combined data analysis demonstrated a significantly lower increase in serum creatinine levels after surgery in the CA group compared with the PN group (p = 0.003). Similarly, there was a noteworthy decrease in the estimated glomerular filtration rate after surgery in the PN group compared with the CA group (p < 0.0001). While not statistically significant, the CA group showed a lower postoperative dialysis rate (p = 0.11). Regarding oncological outcomes, the analysis revealed no significant differences between CA and PN concerning local recurrence (p = 0.2) and distant metastasis (p = 0.12), respectively.

CONCLUSIONS

Our analysis indicates comparable efficacy between PN and CA in controlling tumour recurrence and metastasis. However, CA is associated with superior preservation of renal function, significantly enhanced perioperative outcomes, and fewer postoperative complications. Based on our data, it can be inferred that the scope for applying CA might be expanded to encompass more patients seeking a less invasive treatment option.

Neocapsular reconstruction for challenging partial nephrectomy: A feasibility study in a porcine model and recent clinical experience

OBJECTIVES

Multifocal renal masses and large central-endophytic tumors can be challenging for partial nephrectomy (PN) due to the paucity of capsule remaining after tumor removal. Our objective was to develop a neocapsule to provide tamponade and test its feasibility/safety in a porcine model.

METHODS

Eight live pigs (50-70 kg) underwent unclamped open right flank PN. Renal defects were 1 cm deep and had moderate ongoing venous bleeding. A 6 × 9 inch sheet of Nu-knit® was used for neocapsular reconstruction with Fibrillar™ packing to provide modest tamponade and preclude ongoing bleeding. Blood chemistry and hemoglobin (Hb) levels were drawn preoperatively and postoperative Days 3/5/8. On postoperative Day 8, euthanasia was performed, and both kidneys were inspected and analyzed for histologic changes.

RESULTS

PN defects ranged from 1 × 1 × 1 cm to 4 × 2 × 1 cm; four pigs had PN performed in both poles and four in one pole. Neocapsular reconstruction was successful (n = 8), with no perioperative complications. Median baseline Hb was 10.4 g/dL, and median Hb postoperative Days 3/5/8 were 10.0/10.8/10.6 g/dL, respectively. Median baseline serum creatinine (SCr) was 1.9 mg/dL, and median SCr postoperative Days 3/5/8 were 1.5/1.4/1.5 mg/dL, respectively. At sacrifice, no significant hematomas were observed. Other than adjacent to the PN site, there were no significant histologic changes in the parenchyma for operative kidneys versus controls. Based on our experience, we recently performed neocapsular reconstruction safely/effectively after extensive PN for multifocal tumors and for an allograft with difficult-to-manage subcapsular hematoma.

CONCLUSIONS

Neocapsular reconstruction after PN or capsular trauma appears feasible and safe and may be considered to reduce the risk of perioperative bleeding. However, further study will be needed to confirm the utility/efficacy of this approach.

Parenchymal volume analysis to assess longitudinal functional decline following partial nephrectomy

OBJECTIVE

To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN).

PATIENTS AND METHODS

Of 1140 patients managed with PN (2012-2014), 349 (31%) had imaging/serum creatinine levels pre-PN, 1-12 months post-PN (new baseline), and >3 years later necessary for inclusion. Parenchymal-volume analysis was used to determine split renal function. Patients were grouped as having significant renal comorbidity (CohortSRC : diabetes mellitus with insulin-dependence or end-organ damage, refractory hypertension, or severe pre-existing chronic kidney disease) vs not having significant renal comorbidity (CohortNoSRC ) preoperatively. Multivariable regression was used to identify predictors of annual ipsilateral parenchymal atrophy and functional decline relative to new baseline values post-PN, after the kidney had healed.

RESULTS

The median follow-up was 6.3 years with 87/226/36 patients having cold/warm/zero ischaemia. The median cold/warm ischaemia times were 32/22 min. Overall, the median tumour size was 3.0 cm. The preoperative glomerular filtration rate (GFR) and new baseline GFR (NBGFR) were 81 and 71 mL/min/1.73 m2 , respectively. After establishment of the NBGFR, the median loss of global and ipsilateral function was 0.7 and 0.4 mL/min/1.73 m2 /year, respectively, consistent with the natural ageing process. Overall, the median ipsilateral parenchymal atrophy was 1.2 cm3 /year and accounted for a median of 53% of the annual functional decline. Significant renal comorbidity, age, and warm ischaemia were independently associated with ipsilateral parenchymal atrophy (all P < 0.01). Significant renal comorbidity and ipsilateral parenchymal atrophy were independently associated with annual ipsilateral functional decline (both P < 0.01). Annual median ipsilateral parenchymal atrophy and functional decline were both significantly increased for CohortSRC compared to CohortNoSRC (2.8 vs 0.9 cm3 , P < 0.01 and 0.90 vs 0.30 mL/min/1.73 m2 /year, P < 0.01, respectively).

CONCLUSIONS

Longitudinal renal function following PN generally follows the normal ageing process. Significant renal comorbidities, age, warm ischaemia, and ipsilateral parenchymal atrophy were the most important predictors of ipsilateral functional decline following establishment of NBGFR.

Functional recovery after partial nephrectomy: next generation analysis

OBJECTIVES

To provide a more rigorous assessment of factors affecting functional recovery after partial nephrectomy (PN) using novel tools that allow for analysis of more patients and improved accuracy for assessment of parenchymal volume loss, thereby revealing the potential impact of secondary factors such as ischaemia.

PATIENTS AND METHODS

Of 1140 patients managed with PN (2012-2014), 670 (59%) had imaging and serum creatinine levels measured before and after PN necessary for inclusion. Recovery from ischaemia was defined as the ipsilateral glomerular filtration rate (GFR) saved normalised by parenchymal volume saved. Acute kidney injury was assessed through Spectrum Score, which quantifies the degree of acute ipsilateral renal dysfunction due to exposure to ischaemia that would otherwise be masked by the contralateral kidney. Multivariable regression was used to identify predictors of Spectrum Score and Recovery from Ischaemia.

RESULTS

In all, 409/189/72 patients had warm/cold/zero ischaemia, respectively, with median (interquartile range [IQR]) ischaemia times for cold and warm ischaemia of 30 (25-42) and 22 (18-28) min, respectively. The median (IQR) global preoperative GFR and new baseline GFR (NBGFR) were 78 (63-92) and 69 (54-81) mL/min/1.73 m2 , respectively. The median (IQR) ipsilateral preoperative GFR and NBGFR were 40 (33-47) and 31 (24-38) mL/min/1.73 m2 , respectively. Functional recovery correlated strongly with parenchymal volume preserved (r = 0.83, P < 0.01). The median (IQR) decline in ipsilateral GFR associated with PN was 7.8 (4.5-12) mL/min/1.73 m2 with loss of parenchyma accounting for 81% of this loss. The median (IQR) recovery from ischaemia was similar across the cold/warm/zero ischaemia groups at 96% (90%-102%), 95% (89%-101%), and 97% (91%-102%), respectively. Independent predictors of Spectrum Score were ischaemia time, tumour complexity, and preoperative global GFR. Independent predictors of recovery from ischaemia were insulin-dependent diabetes mellitus, refractory hypertension, warm ischaemia, and Spectrum Score.

CONCLUSIONS

The main determinant of functional recovery after PN is parenchymal volume preservation. A more robust and rigorous evaluation allowed us to identify secondary factors including comorbidities, increased tumour complexity, and ischaemia-related factors that are also independently associated with impaired recovery, although altogether these were much less impactful.

Selective Use of Neoadjuvant Targeted Therapy Is Associated with Greater Achievement of Partial Nephrectomy for High-complexity Renal Masses in a Solitary Kidney

Background

Partial nephrectomy (PN) is preferred for a renal mass in a solitary kidney (RMSK), although tumors with high complexity can be challenging.

Objective

To evaluate the evolution of RMSK management with a focus on achievement of PN.

Design setting and participants

Patients with nonmetastatic RMSK (n = 499) were retrospectively reviewed; 133 had high tumor complexity, including 80 in the pre-tyrosine kinase inhibitor (TKI) era (1999-2008) and 53 in the TKI era (2009-2022). After 2009, 23/53 patients received neoadjuvant TKI and 30/53 had immediate-surgery.

Outcome measurements and statistical analysis

Functional outcomes, adverse events and complications, dialysis-free survival, and recurrence-free survival (RFS) were the measures evaluated. Mann-Whitney and χ2 tests were used to compare cohorts, and the log-rank test was applied for survival analyses.

Results and limitations

Overall, the median RENAL score was 10 and the median tumor diameter was 5.2 cm. Demographic characteristics, tumor diameter, and RENAL scores were similar between the pre-TKI-era and TKI-era groups. In the TKI era, 23/53 patients (43%) with clear-cell histology were selected for neoadjuvant TKI. These 23 patients had a greater median tumor diameter (7.1 vs 4.4 cm; p = 0.02) and RENAL score (11 vs 10; p = 0.07). After TKI treatment, the median tumor diameter decreased to 5.6 cm and the RENAL score to 9, and tumor volume was reduced by 59% (all p < 0.05). PN was accomplished in 21/23 (91%) the TKI-treated cases and in 27/30 (90%) of the immediate-surgery cases (2009-2022). PN was only accomplished in 52/80 (65%) of the patients from the pre-TKI era (p < 0.01). The 5-yr dialysis-free survival rate was 59% in the pre-TKI-era group and 91% in the TKI-era group. The 5-yr RFS rate was lower in the TKI-era group (59% vs 74%; p = 0.21), which was mostly related to more aggressive tumor biology, as reflected by a predominance of systemic rather than local recurrences.

Conclusions

Management of RMSK with high tumor complexity is challenging. Selective use of TKI therapy was associated with greater use of PN, although a randomized study is needed. RFS mostly reflected aggressive tumor biology rather than failure of local management.

Patient summary

For complex kidney tumors in patients with a single kidney, management is challenging. Use of drugs called tyrosine kinase inhibitors before surgery was associated with reductions in tumor size and greater ability to achieve partial kidney removal for cancer control. Most recurrences were metastatic, which reflects aggressive tumor biology rather than failure of surgery.

Perioperative, functional, and oncologic outcomes after ablation or partial nephrectomy for solitary renal tumors: a systematic review and meta-analysis of comparative trials

Objectives

The perioperative, functional, and oncological outcomes of patients with solitary small renal tumors (SRMs) treated with ablation (AT) or partial nephrectomy (PN) remain controversial. The aim of this study was to compare the outcomes of these two surgical techniques.

Methods

In April 2023, we conducted a literature search in several widely used databases worldwide, including PubMed, Embase, and Google Scholar. Review Manager was used to compare various parameters. The study was registered with PROSPERO (CRD42022377157).

Results

Our final meta-analysis included 13 cohort studies with a total of 2,107 patients. Compared to partial nephrectomy (PN), ablation (AT) had shorter hospital stays (WMD -2.37 days, 95% CI -3.05 to -1.69; p < 0.00001), shorter operating times (WMD -57.06 min, 95% CI -88.92 to -25.19; p = 0.0004), less postoperative creatinine increases (WMD -0.17 mg/dL, 95% CI -0.29 to -0.05; p = 0.006), less postoperative glomerular filtration rate decreases (WMD -9.84 mL/min/1.73 m2, 95% CI -14.25 to -5.44; p < 0.0001), less postoperative new-onset chronic kidney disease (OR 0.33, 95% CI 0.16 to 0.71; p = 0.005), and less intraoperative blood loss (WMD -285.92 ml, 95% CI -428.44 to -143.40; p < 0.0001). The transfusion rate was lower in the ablation group (OR 0.17, 95% CI 0.06 to 0.51; p = 0.001). The risk of local recurrence was higher in the ablation group (OR 2.96, 95% CI 1.27 to 6.89; p = 0.01), while the risk of distant metastasis was higher in the partial nephrectomy group (OR 2.81, 95% CI 1.28 to 6.18; p = 0.01). The intraoperative and postoperative complication rates were lower in the ablation group (OR 0.23, 95% CI 0.08 to 0.62; p = 0.004 and OR 0.21, 95% CI 0.11 to 0.38; p < 0.00001, respectively). However, overall survival, postoperative dialysis rate, and tumor-specific survival were not different between the two groups.

Conclusions

Our data suggest that ablation and partial nephrectomy are equally safe and effective in the treatment of small solitary kidney tumors and are better options for patients with poor preoperative physical condition or poor renal function.