‘BJUI Clinical Dilemma’: the incidental small renal mass in a solitary kidney

Abstract

The incidental small renal mass (SRM; ≤4 cm; clinical T stage [cT]1a) has become increasingly common due to the widespread utilisation of ultrasonography and cross-sectional imaging. Today, most such patients present with asymptomatic, localised disease that can be surgically treated with curative intent; however, up to 25% of SRMs are benign [1]. This creates a clinical dilemma: balancing the removal of malignant tumours with avoiding needless active treatment for benign masses.

This ‘BJUI Clinical Dilemma’ presents a structured format to address the common clinical presentation of a SRM through a case vignette approach. Following the vignette, leading experts will provide brief commentary, explaining the rationale behind their preferred management strategies. This approach encourages a balanced, expert-driven discussion on alternative strategies, offering readers insights into decision-making processes for common, yet nuanced cases in urological practice.

A 63-year-old man presented to his primary care physician with an incidental CT finding of a 2.9-cm left renal mass in a congenital solitary left kidney, something the patient was previously unaware of, as part of an emergency room evaluation for brief epigastric pain—now completely resolved. He is an unmarried schoolteacher. He is overweight (body mass index of 29.7 kg/m²) and has well-controlled hypertension (on atenolol). He denies any history of smoking or occupational exposures and has no relevant family history.

He denies any urinary symptoms, haematuria, flank pain, weight loss, or constitutional symptoms. His blood pressure is within the normal range, and physical examination reveals moderate central abdominal adiposity without any palpable masses or surgical scars.

A full blood count and comprehensive metabolic panel are normal; urine analysis is unremarkable. Creatinine is 88 μmol/L and estimated GFR (eGFR) is 75 mL/min/1.73 m².

A contrast-enhanced CT scan was performed, including images without and with contrast during the arterial phase, revealing a 2.9 × 2.7 cm enhancing, exophytic renal mass arising from the posterior interpolar region of the left kidney (Radius, Exophytic/Endophytic, Nearness to collecting system or sinus, Anterior/Posterior, Location [R.E.N.A.L.] nephrometry score 8; Fig. 1). The mass briskly enhances, is well-defined, and appears to be predominantly solid. There are no signs of sinus, renal vein or perinephric fat invasion and no enlarged regional lymph nodes. The contralateral kidney is absent. A diagnostic chest X-ray was unremarkable.

The patient seeks your opinion as to what would be his best course of action.

This is a complex clinical scenario requiring individualised care, ideally delivered at a referral centre by an experienced multidisciplinary team (MDT). The case has many interconnected decision-points (Table 1) [2, 3].

The CT characteristics of the mass raise suspicion for RCC. While biomarkers are not integrated into routine diagnostic pathways for suspicious SRM [4], knowledge of the histology may improve risk-stratification and counselling. In this case, RMB appears safe and feasible and should be discussed with the patient. Yet, concerns about its feasibility, morbidity, and accuracy (especially in the WHO 2022 era) could limit its clinical value [5]. Likewise, novel promising ‘virtual biopsy’ tools are not yet ready for prime time and could paradoxically jeopardise decision-making [6]. To improve pre-treatment risk stratification, renal scintigraphy and potentially a nephrological consultation could be of value [2, 7].

Treatment options other than surgery could have specific drawbacks in this case. Active surveillance (AS) with potential delayed intervention is safe in carefully selected patients with a SRM [3] and should be transparently discussed. Yet, in this case—a patient with a low comorbidity burden, no red flags for increased perioperative risk, long life expectancy and a localised SRM in a solitary kidney—the AS risk–benefit profile is nuanced and may worsen over time. While the concept of ‘cure’ is evolving, to date the evidence comparing partial nephrectomy (PN) and ablation techniques for SRMs is still limited [8]. This concept is even more critical in patients with a solitary kidney, for whom the prevailing uncertainty regarding long-term oncological outcomes of ablation techniques could be critical.

Surgery remains the ‘gold standard’ treatment of localised RCC and would have an imperative indication in this case. PN has distinct benefits and can achieve pragmatic goals of care (Table S1). However, it is invasive and highly demanding in a patient with a solitary kidney, prompting centralisation to appropriate settings and experienced teams (Table S2). In our case, the patient is fit for surgery; the tumour is small, organ-confined, and moderately complex; despite the solitary kidney, baseline renal function is preserved. From a functional perspective, PN could represent ‘the right choice at the right time’. If left untreated, tumour size and/or complexity may increase over time, with the subsequent risk of missing a window of opportunity for a safe and effective PN. While the risk of postoperative acute kidney injury is real, new baseline and long-term renal function will likely remain stable with tailored postoperative care [9]. Lastly, from an oncological perspective, PN is still the ‘safest’ option for the patient considering the biological heterogeneity of RCC, the shortcomings of biopsy and imaging to inform on disease biology, and the uncertainty regarding the best timing of treatment in a patient with such a long life expectancy.

Patient empowerment is crucial to reach value-based shared decision-making, especially in complex/rare clinical scenarios. Of note, in individual patients, prioritising available management options according to their expected clinical results is a responsibility of clinicians; selecting the management option that fosters benefit in each case is a responsibility of well-informed patients after well-calibrated counselling. As such, while minimally invasive PN would be my preferred option for this case, it should only be performed if this recommendation matched to patient preference and values.

The stakes are relatively high given the solitary kidney. Active intervention, whether surgical or ablative may lead to a reduction in renal function, albeit slightly less with the latter. Robot-assisted PN is associated with a major (Clavien–Dindo Grade ≥III) complication rate of 5% [10]. The rate of conversion to radical nephrectomy is very low, but not negligible, with published figures from high-volume centres ranging from 0.7% to 5% [10]. However unlikely, such a consequence would be life changing in this case because of the need for dialysis and potentially a future kidney transplant. Ablative therapies for SRMs such as radiofrequency ablation (RFA) and cryotherapy are associated with an overall complication rate of 11.3% and a major complication rate of 6.6%, such as pneumothorax and ureteric stricture formation [11]. Therefore, it would be important to ascertain that the benefit of active treatment would outweigh the accompanying potential risk of the intervention to enable an informed treatment decision.

Current conventional cross-sectional imaging, such as the contrast-enhanced CT, that this patient has had is unable to reliably differentiate benign from malignant renal tumours. RMB can be considered but is also not without risk. The overall complication rate is 8.1%, and while most are Clavien–Dindo Grade ≤II; pneumothorax, post-biopsy pyelonephritis and pseudoaneurysm requiring embolisation have also been reported [5].

A non-invasive molecular imaging modality that has been routinely used for decades in the diagnostic imaging of the heart, parathyroid and breast is technetium-99m (^99mTc)-sestamibi single-photon emission (SPECT)/CT. It is available in most nuclear medicine hospital departments and is known to be very safe, with only one reported case of allergy/angio-oedema in the literature. ^99mTc-sestamibi is a lipophilic, cationic radiopharmaceutical that is readily taken up by cells with high levels of mitochondria [12], such as oncocytomas, the most common type of benign solid renal tumour found at PN. RCCs on the other hand generally have lower levels of mitochondria relative to normal renal epithelial cells and also express multi-drug resistance pumps, which export ^99mTc-sestamibi from the cells [12]. These underlying differences result in oncocytomas appearing avid and RCC appearing photopenic on ^99mTc-sestamibi SPECT/CT. A recent systematic review and meta-analysis of eight studies involving 489 patients with 501 renal tumours reported the sensitivity of ^99mTc-sestamibi SPECT/CT for renal oncocytoma and hybrid oncocytic/chromophobe tumours (HOCTs) vs all other renal lesions to be 89% (95% CI 70–97%) and specificity of 89% (95% CI 86–92%) [13].

A ^99mTc-sestamibi SPECT/CT can be very helpful in this case to provide further clarity on the nature of renal tumour and guide the discussion on appropriate management. Should the tumour be photopenic on ^99mTc-sestamibi SPECT/CT then active treatment options can be discussed, with the knowledge that the risks involved with intervention are likely outweighed by the potential benefits of treating a malignant lesion. If the tumour is avid, then it is highly probable to be an oncocytoma or HOCT, and the patient can be counselled on the options of AS, a confirmatory RMB or ablative treatment, given the indolent nature of such tumours.

Clear cell RCC (ccRCC) is the most lethal form of RCC accounting for >90% of those with advanced disease. Over 90% of ccRCCs are characterised by the mutational loss of Von Hippel–Lindau, which leads to dysregulation of hypoxia-inducible factor and downstream overexpression of carbonic anhydrase IX (CAIX). CAIX is a cell surface receptor, which is ubiquitously expressed in ccRCC in >95% of all ccRCC (primary or metastatic sites). As it is not found in normal tissue other than slight expression in the biliary tract, targeting this protein has been proposed for both diagnostic and therapeutic purposes. Girentuximab is a highly specific, monoclonal antibody that targets CAIX with high affinity. Girentuximab has minimal toxicity and can be radiolabeled for imaging with ¹²⁴I and ⁸⁹Zr with the only drawback being a modest delay between dosing and imaging (3–7 days). The REDECT trial used ¹²⁴I-girentuximab positron emission tomography (PET)/CT and compared outcomes to contrast-enhanced CT in patients with renal masses scheduled for resection. The ¹²⁴I-girentuximab showed improved sensitivity (86% vs 76%, P = 0.023) and specificity (85.9% vs 46.8%, P = 0.005) for ccRCC as compared to contrast-enhanced CT [14]. Efficacy data from ZIRCON (ClinicalTrials.gov identifier: NCT03849118), an open label multicentre clinical trial with >300 patients, showed that zirconium-89 (⁸⁹Zr)-girentuximab (TLX250-CDX) PET/CT demonstrates 85.5% and 87% sensitivity and specificity in the diagnosis of ccRCC, far exceeding the data on sensitivity and specificity from cross-sectional imaging [15]. The modality appears to work just as well in lesions as small as 2 cm. Several of the false positives were other forms of cancer (papillary and sarcoma), which likely has physiological hypoxia (also expressing CAIX). Thus, the TLX250-CDX PET/CT would have a positive predictive value (PPV) of >99% [15].

For this gentleman with a 2.9-cm renal mass in a solitary kidney, if available, a TLX250-CDX PET/CT scan would be a safe initial, non-invasive method with minimal side effects. This scan will help risk stratify the lesion by elucidating if the mass is truly malignant, while providing insight into disease biology including the potential for more aggressive disease biology—something that will likely impact treatment decisions.

In selecting between the two nuclear medicine scans, sestamibi and TLX250, there are some important considerations. The TLX250 scan has a high PPV for any renal malignancy, and while the negative predictive value (NPV) is low due to non-CAIX expressing renal tumours, these are more likely to be benign or indolent in nature. Moreover, the results of the trial using TLX250 demonstrated the scan has high inter-reader reliability and good accuracy regardless of size (equivalent for tumours <2 cm) and location. The sestamibi scan on the other hand, has the benefit of being performed in 1 day, while TLX 250 requires two separate visits for the injection and scan. Sestamibi, as indicated above has a good accuracy for determining if a lesion is an oncocytoma or at worst, HOCTs/small chromophobe that are very indolent in nature. Finally, although still not widely utilised, sestamibi scan does have more real work evidence to support its use.

Renal cell carcinoma is a common and deadly disease that the urological oncology community views through a half century old lens. This lens is antiquated; its optics are murky, and the entrenched bias and stagnation impedes progress. Indeed, the perception of a RMB for SRM as a ‘dilemma’—or, as many guidelines suggest, an option—is a testament to our cultural and non-data-driven biases. Nearly every other oncological specialty considers biopsy a standard diagnostic step, barring exceptional circumstances [1]. Yet, urological oncologists persist in skipping this critical step based on archaic fears and discredited theories.

The excuse of tumour seeding from RMB has been largely invalidated. The risk of seeding is low (0.0019% in a meta-analysis of 57 studies with 5228 patients), akin to the probability of dying in a car crash after a medical visit—a rationale that would be laughable if it were not so tragically influential in clinical decision-making [1]. Similarly, claims that biopsies complicate subsequent surgeries have been conclusively disproven by over a decade of clinical practice showing that biopsies do not adversely affect surgical outcomes [16].

Furthermore, the scepticism over the diagnostic reliability of RMB is a thinly veiled excuse. A review of literature confirms that RMB is as accurate, or more so, than other organ system biopsies where biopsy is regarded as standard care before surgery (breast, prostate, lung, pancreas, thyroid, and liver). With an impressive sensitivity and specificity, both at 98%, RMB exhibits almost flawless accuracy in diagnosing cancer. This reliability is underscored by a PPV of 99.8%, assuring that positive diagnoses genuinely represent the underlying condition. The NPV of 69% and the inconclusive rate of 14% are attributable to the failed biopsy of normal renal tissue, which is minor given that inconclusive results substantially decrease to 2.8% after subsequent biopsy [1]. To note, RMB has an exceptionally low biopsy complication rate (<1%); a mere fraction for other organs, such as the lung and prostate, which can have complication rates as high as 6% and 4%, respectively [1].

If we dismiss the misconception of RMB as a ‘dilemma’, the outcomes speak for themselves. In our series of 192 patients with SRMs, routine pre-treatment RMB significantly enhances outcomes. Among patients undergoing RMB, 37% avoid unnecessary surgery and instead enjoy AS, with only 3% needing a subsequent procedure over an average of 6 years. Moreover, 38% undergo outpatient percutaneous ablation, with 89.5% requiring no further treatment and none experiencing disease progression. Best of all, the risk of ‘needless’ nephrectomy (surgery performed for benign disease) plummets from 20% to 25% to a mere 3% [1].

Surgical oncology often mandates pre-treatment biopsy unless you have a very compelling reason. The urological oncology community remains creative in its rationalisations, but these are running out. Let us be true to the prime directive of our basic oath, ‘do not harm’. There is no dilemma to proceed with a RMB.

Current guidelines for management of SRMs recommend a multi-phase (i.e., without and with intravenous contrast) CT or MRI examination as the first step in the evaluation of an indeterminate renal mass [8]. Historically, the goal of additional imaging was to determine the presence of enhancement, which virtually confirms the mass being a neoplasm, and to exclude the presence of macroscopic fat, which in the absence of calcifications is diagnostic of a benign classic angiomyolipoma (AML) [8]. In this patient, a multiphase CT confirmed the presence of enhancement and absence of macroscopic fat. Nevertheless, the goal of additional imaging has extended in recent years to further discriminate between different renal masses, the so-called ‘virtual biopsy’.

The MRI-based clear cell likelihood score (ccLS) is a 5-point Likert scale that informs of the likelihood of an indeterminate solid renal mass to represent ccRCC, the most common and frequently aggressive form of kidney cancer [17]. The ccLS is based on a standard multiparametric MRI protocol. In a retrospective study at five academic centres, 10 abdominal radiologists (two radiologists per site) without previous experience with the ccLS system independently assigned a ccLS to 250 indeterminate SRMs (50/site) after a 1.5-h training session [17]. The pooled sensitivity, specificity, and PPV for ccRCC of ccLS ≥4 were 75% (95% CI 68–81%), 78% (95% CI 72–84%), and 76% (95% CI 69–81%), respectively. The NPV of ccLS was 88% (95% CI 81–93%) [17]. The ccLS has been validated in other single-centre studies with comparable results. In a systematic review of six studies including 825 renal masses (875 patients), the reported pooled sensitivity and specificity for cT1a renal masses were 0.80 (95% CI 0.75–0.85) and 0.74 (95% CI 0.65–0.81) applying a ccLS of ≥4 [18]. The reported interobserver agreement of ccLS is moderate to good (mean between 0.53 and 0.83).

The SRM in this patient, exhibiting avid corticomedullary enhancement (i.e., at CT), should receive a ccLS of 5 at MRI if there is microscopic fat present. Overall, ~40% of SRMs receive a ccLS of 5 [17]. The PPV for ccRCC and malignancy in a ccLS of 5 SRM is 90% and 94%, respectively [19]. An additional 25% of SRMs receive a ccLS of 4 and of those, ~75% are ccRCC, ~91% malignant, and ~9% benign (largely oncocytomas and oncocytic neoplasms) [16]. The likelihood of benign and indolent histology increases to ~40% in SRMs with a ccLS of 3 [19, 20]. A ccLS of 2 has moderate sensitivity of 33–67% although high PPV of 67–100% for fat-poor AML (fpAML), despite a low pre-test probability (<5% of surgically resected cT1a renal masses are fpAML) [21]. In this patient, an MRI can help guide management by providing additional information about the risks of clear cell vs benign/indolent histology, facilitating the decision to proceed with AS, RMB, or definitive therapy.

The patient wishes to have a biopsy before making any further decisions. A percutaneous RMB is performed without complication. Pathology demonstrates Grade 2 ccRCC without variant histology. Your patient schedules a follow-up visit and asks your opinion on treatment.

Surgery is generally regarded as the ‘gold standard’ approach for the SRM if technically feasible, particularly in imperative situations such as this case with a single kidney [18]. This is a Grade 2 RCC with the potential to grow and ultimately metastasise; indeed, final pathology could upgrade this to a Grade 3 tumour. Ablation has too high a recurrence rate and risks damaging the collecting system and vasculature in this hilar tumour, while surveillance is not practical in the medium/longer term in a fit man aged 63 years.

The surgical approach to be used depends on the experience of the surgeon and the availability of modern technology, specifically the surgical robot. Although some centres would still favour open surgery with ice cooling through a loin incision, most units with significant robot-assisted PN experience would take on this case. The single kidney situation is no longer a rarity, as for instance our own unit would have seen this presentation >40 times out of >1000 robot-assisted PNs. However, it is not a case for the beginner or low -volume centre given the high stakes.

As the patient has a congenital single kidney it is likely larger in size than a standard kidney and is well-functioning with an eGFR of 89 mL/min/1.73 m². This suggests the kidney should be relatively resistant to ischaemia and will still function well despite a small loss of tissue related to a PN. It also means that a segmental clamp technique could be employed to preserve perfusion to a significant part of the kidney. A bespoke three-dimensional model would be useful to indicate the detailed vascular supply and the potential for partial ischaemia as part of the preoperative planning. If there is no potential for a segmental/partial clamp, then an early unclamp technique would help reduce the warm ischaemia time.

Today, PN remains the ‘gold standard’ treatment for cT1a renal cancer; however, there is a small risk of conversion into radical nephrectomy intraoperatively. We conducted a recent systemic review meta-analysis that included 32 observational cohort studies and one randomised controlled trial, providing a total of 74 946 patients. The patients having image-guided ablation (IGA) were older than those with PN (mean difference [MD] 5.70, 95% CI 3.83–7.58). Indeed, stage T1a patients, patients treated with IGA had significantly worse overall survival (hazard ratio [HR] 1.64, 95% CI 1.39–1.95). For patients with >5 years of follow-up, the local recurrence-free survival for IGA was similar to patients treated with PN (HR 1.54, 95% CI 0.88–2.71). The overall findings for patients treated with IGA with stage T1a, showed similar cancer-specific survival, metastasis-free survival, disease-free survival, with significantly less postoperative complications (risk ratio 0.72, 95% CI 0.55–0.94), and less decline in postoperative eGFR (MD −7.42, 95% CI −13.1 to 1.70) compared to PN. This corroborates that ablation can be offered in preference to PN when renal preservation is vital [22].

Our patient has R.E.N.A.L. nephrometry score of 8, indicating a moderate risk for surgery given its posterior-medial location. Our published long-term patients cohort series revealed that all oncological outcomes for patients with T1a renal cancer treated with image-guided renal cryoablation and RFA had comparable outcomes to minimally invasive PN (P > 0.05). More importantly, IGA patients had lower reduction in eGFR postoperatively compared to PN (P < 0.001). Given the present case scenario where the need for preservation of renal function is crucial, the renal cancer MDT consensus would be to offer IGA as a preference, given our expertise and proven track record of providing good long-term oncological durability and preservation of renal function [11]. However, there are some technical considerations for the interventional radiologist to be aware of when treating an upper pole renal tumour as there is a small risk of pneumothorax and ablative injury to the nerve along the psoas muscle. The process of consent would be crucial to explain the risk and the steps required to mitigate the complication.

If the decision for active treatment is made, then the goals of management in a solitary kidney are to maximise oncological control but avoid renal replacement therapy. PN, if feasible, should be considered in this 63-year-old; however, if the patient declines surgery or has some other incidental contraindication upon anaesthetic evaluation, SABR may be an ideal therapeutic alternative. Furthermore, if a total nephrectomy is offered as the surgical approach, SABR can be used as a nephron-sparing alternative in the first instance.

Stereotactic ablative body radiotherapy is a newer, non-invasive, nephron-sparing modality for primary RCC that can be delivered in an outpatient setting with as little as a single visit. A recent multicentre co-operative group clinical trial, Trans-Tasman Radiation Oncology Group (TROG) 15.03 FASTRACK II (ClinicalTrials.gov identifier: NCT02613819), reported a local control rate of 100% at a median follow-up of 43 months [23]. Most tumours were ≥T1b (not SRMs) with a median diameter of 4.6 cm. The baseline mean eGFR was 61.1 mL/min/1.73 m². Despite the relatively large tumours treated, and unfavourable pre-existing chronic kidney disease, loss in renal function was comparable to the PN series, with an average loss in eGFR of 14.6 mL/min/1.73 m² from baseline.

Of the ablative treatment options, SABR has the most robust clinical trial evidence base. A recent systematic review included 12 prospective clinical trials of SABR for primary RCC [24]. The median local control rate was 94.1% in a cohort with a weighted median maximum tumour size of 4.4 cm. This systematic review included 81 patients with a solitary kidney, with a baseline eGFR of 64.6 mL/min/1.73 m². The mean eGFR decrease was 5.8 mL/min/1.73 m² (−9% from baseline). None of the patients required dialysis.

As the efficacy of thermal ablation reduces with tumours >3 cm in size or locations close to the ureter, renal pelvis, or renal vessels, SABR is particularly suited to larger tumours. Furthermore, by contrast to thermal ablation, SABR is not limited by proximity to renal pelvis structures or ureters, nor by completely endophytic tumours; however, a limitation of SABR is direct tumour contact with the bowel. Whereas hydro-displacement of the bowel is possible prior to thermal ablation, SABR does not afford this opportunity as a non-invasive approach.

In summary, in this patient, non-invasive SABR is likely to afford excellent oncological and renal function preservation outcomes.

Active surveillance is initial monitoring of tumour size by serial imaging with delayed intervention for tumours showing clinical progression during follow-up [8]. This differs from watchful waiting, which is reserved for those with comorbidity that precludes treatment and does not require follow-up imaging or other measures. Evidence based clinical guidelines include the AS option with various caveats.

This treatment option was initially suggested by autopsy findings of incidental RCC and retrospective imaging reviews where apparent RCCs were unchanging over years. This led to many reports with follow-up of asymptomatic and therefore incidental SRMs consistent with RCC or even biopsy confirmed RCC, revealing little or no change in size over years (local progression) and a low rate of progression to metastases (<5%). These findings led to the recognition of asymptomatic SRM as a clinical entity. Importantly, biopsy revealed that up to 30% were benign. Unlike many other tumour types (breast ductal carcinoma in situ, thyroid papillary carcinoma and prostate cancer), treatment decisions without biopsy continue in management of SRMs [1].

The pattern of local progression of biopsy confirmed RCC is heterogeneous. Very few grow rapidly (<10% but have a higher rate of metastatic progression) and many remain unchanged. Histological subtypes vary in their growth rate (biopsy confirmed RCC grow faster); however, growth may occur at any time, which is a clinical marker or trigger for treatment. Symptoms rarely develop. There are, currently, no clinically useful markers to identify this subpopulation. Although follow-up frequency and modality vary between clinicians, a typical routine would be imaging every 3–6 months with cross-sectional imaging and/or ultrasound.

Age and comorbidity remain important considerations in SRM management. AS is clearly attractive in the elderly, but the index case is a relatively healthy, mildly obese, non-diabetic 63-year-old man who should have an average life expectancy of 85 years in the UK. Implications for treatment are individualised by location and size of the tumour, plus the distribution of the obesity (this man has an exophytic posterior tumour with manageable subcutaneous fat). This patient has ready access for ablation or PN.

Informed shared decision-making is important, and the option of AS should be included in management discussions. Patient anxiety and anticipated follow-up compliance are important long-term considerations.

A nuanced and individualised approach is essential in SRM management. This case vignette highlights the challenges of balancing oncological efficacy with needless intervention. From direct surgery to advanced imaging and minimally invasive alternatives, each expert's perspective provides insights into the strengths and limitations of their recommended approach.

As the prevalence of SRMs rises, we hope these insights serve as a valuable guide for clinicians navigating similar clinical dilemmas (Table 1).

Grant D. Stewart has received educational grants from Pfizer, AstraZeneca and Intuitive Surgical; consultancy fees from Pfizer, MSD, EUSA Pharma and CMR Surgical; Travel expenses from MSD and Pfizer; Speaker fees from Pfizer; Clinical lead (urology) National Kidney Cancer Audit and Topic Advisor for the National Institute for Health and Care Excellence (NICE) kidney cancer guideline. Maxine Tran has received consultancy fees from MSD and Boston Scientific; travel and speaker fees from Angiodynamics; and is a committee member for the NICE kidney cancer guideline and the European Association of Urology (EAU) kidney cancer guidelines. Tze Min Wah has received research grants from HistoSonics, Neuwave (Johnson & Johnson), Better Medicine and Boston Scientific; honorarium and educational grant from Angiodynamics; and is a committee member for the NICE kidney cancer guideline. Brian Such has served as a consultant for Telix Pharmaceuticals, Veracyte, and Merck. Ivan Pedrosa has received warrants from Health Tech International for his role as consultant.