Identifying the facilitators and barriers to implementation of renal tumour biopsy in the diagnostic pathway for small renal masses.

OBJECTIVES: To understand the facilitators and barriers to the implementation of renal tumour biopsy (RTB) in the diagnostic pathway for renal tumours in England. PATIENTS AND METHODS: Participants consisted of patients who had a renal tumour diagnosed and/or treated at one of five tertiary centres in England, healthcare professionals involved in the direct care of patients diagnosed with renal tumours, and clinical service managers and commissioners. The study employed a mixed-methods research methodology consisting of individual interviews and an on-line survey that explored the types of facilitators and barriers individuals perceived and experienced and the frequency in which these were reported. A public dissemination event took place following the completion of data collection; to facilitate discussion of potential solutions to implementing RTB. RESULTS: There were 50 participant interviews (23 patients, 22 clinicians, and five health service commissioners/operations managers). The patient on-line survey received 52 responses, and the clinician survey received 22 responses. Patients most frequently reported influences in choosing whether to undergo RTB pertained to wanting to know the diagnosis of their kidney mass (40%), the advice or information provided by healthcare professionals (40%), and not wishing to delay treatment (23%). Clinicians most frequently reported barriers to recommending RTB related to their uncertainty of diagnostic accuracy (56%), availability of appointments or hospital beds (52%), concerns of risk of bleeding (44%), risk of seeding (41%), and delays in meeting national cancer pathway targets (41%). The dissemination event was attended by 18 participants (seven patients and 11 clinicians). Suggestions to improve implementation included reducing variation and promotion of standardisation of practice by a consensus statement, increasing the evidence base (clinicians) and improved communication by developing better patient aids such as videos and diagrams (patients and clinicians). CONCLUSION: Implementation of RTB may be dependent on the quality of information provided, its format and perceived reliability of the information. Increased utilisation of RTB may be improved by development of a consensus statement on the role of biopsy, with patients expressing a preference for alternative information aids such as patient videos.

Management of small testicular masses: outcomes from a single-centre specialist multidisciplinary team.

OBJECTIVES: To report the management outcomes of men with ≤20-mm small testicular masses (STMs) and to identify clinical and histopathological factors associated with malignancy. PATIENTS AND METHODS: A retrospective analysis of men managed at a single centre between January 2010 and December 2020 with a STM ≤20 mm in size was performed. RESULTS: Overall, 307 men with a median (interquartile range [IQR]) age of 36 (30-44) years were included. Of these, 161 (52.4%), 82 (26.7%), 62 (20.2%) and 2 men (0.7%) underwent surveillance with interval ultrasonography (USS), primary excisional testicular biopsy (TBx) or primary radical orchidectomy (RO), or were discharged, respectively. The median (IQR) surveillance duration was 6 (3-18) months. The majority of men who underwent surveillance had lesions <5 mm (59.0%) and no lesion vascularity (67.1%) on USS. Thirty-three (20.5%) men undergoing surveillance had a TBx based on changes on interval USS or patient choice; seven (21.2%) were found to be malignant. The overall rate of malignancy in the surveillance cohort was 4.3%. The majority of men who underwent primary RO had lesions ≥10 mm (85.5%) and the presence of vascularity (61.7%) on USS. Nineteen men (23.2%) who underwent primary TBx (median lesion size 6 mm) had a malignancy confirmed on biopsy and underwent RO. A total of 88 men (28.7%) underwent RO, and malignancy was confirmed in 73 (83.0%) of them. The overall malignancy rate in the whole STM cohort was 23.8%. Malignant RO specimens had significantly larger lesion sizes (median [IQR] 11 [8-15] mm, vs benign: median [IQR] 8 [5-10] mm; P = 0.04). CONCLUSIONS: Small testicular masses can be stratified and managed based on lesion size and USS features. The overall malignancy rate in men with an STM was 23.8% (4.3% in the surveillance group). Surveillance should be considered in lesions <10 mm in size, with a TBx or frozen-section examination offered prior to RO in order to preserve testicular function.

The changing trends of image-guided biopsy of small renal masses before intervention-an analysis of European multinational prospective EuRECA registry.

OBJECTIVES: To evaluate the use of pre-cryoablation biopsy for small renal masses (SRMs) and the effects of increasing uptake on histological results of treated SRMs. METHODS: From 2015 to 2019, patients with sporadic T1N0M0 SRMs undergoing percutaneous, laparoscopic, or open cryoablation from 14 European institutions within the European Registry for Renal Cryoablation (EuRECA) were included for the retrospective analysis. Univariate and multivariate logistic models were used to evaluate the trends, histological results, and the factors influencing use of pre-cryoablation biopsy. RESULTS: In total, 871 patients (median (IQR) age, 69 (14), 298 women) undergoing cryoablation were evaluated. The use of pre-cryoablation biopsy has significantly increased from 42% (65/156) in 2015 to 72% (88/122) in 2019 (p < 0.001). Patients treated for a benign histology are significantly more likely to have presented later in the trend, where pre-cryoablation biopsy is more prevalent (OR: 0.64, 95% CI 0.51-0.81, p < 0.001). Patients treated for undiagnosed histology are also significantly less likely to have presented in 2018 compared to 2016 (OR 0.31, 95% CI 0.10-0.97, p = 0.044). Patients aged 70+ are less likely to be biopsies pre-cryoablation (p < 0.05). R.E.N.A.L. nephrometry score of 10+ and a Charlson Comorbidity Index > 1 are factors associated with lower likelihood to not have received a pre-cryoablation biopsy (p < 0.05). CONCLUSION: An increased use of pre-cryoablation biopsy was observed and cryoablation patients treated with a benign histology are more likely to have presented in periods where pre-cryoablation biopsy is not as prevalent. Comparative studies are needed to draw definitive conclusions on the effect of pre-cryoablation biopsy on SRM treatments. KEY POINTS: • The use of biopsy pre-ablation session has increased significantly from 42% of all patients in 2015 to 74% in 2019. • Patients are less likely to be treated for a benign tumour if they presented later in the trend, where pre-cryoablation biopsy is more prevalent, compared to later in the trend (OR 0.64, 95% CI 0.51-0.81, p < 0.001). • Patients with comorbidities or a complex tumour (R.E.N.A.L. nephrometry score > 10) are less likely to not undergo biopsy as a separate session to cryoablation.

Impact of the first surge of the COVID-19 pandemic on a tertiary referral centre for kidney cancer.

OBJECTIVE: To analyse the impact of the COVID-19 pandemic on a centralized specialist kidney cancer care pathway. MATERIALS AND METHODS: We conducted a retrospective analysis of patient and pathway characteristics including prioritization strategies at the Specialist Centre for Kidney Cancer located at the Royal Free London NHS Foundation Trust (RFH) before and during the surge of COVID-19. RESULTS: On 18 March 2020 all elective surgery was halted at RFH to redeploy resources and staff for the COVID-19 surge. Prioritizing of patients according to European Association of Urology guidance was introduced. Clinics and the specialist multidisciplinary team (SMDT) meetings were maintained with physical distancing, kidney surgery was moved to a COVID-protected site, and infection prevention measurements were enforced. During the 7 weeks of lockdown (23 March to 10 May 2020), 234 cases were discussed at the SMDT meetings, 53% compared to the 446 cases discussed in the 7 weeks pre-lockdown. The reduction in referrals was more pronounced for small and asymptomatic renal masses. Of 62 low-priority cancer patients, 27 (43.5%) were deferred. Only one (4%) COVID-19 infection occurred postoperatively, and the patient made a full recovery. No increase in clinical or pathological upstaging could be detected in patients who underwent deferred surgery compared to pre-COVID practice. CONCLUSION: The first surge of the COVID-19 pandemic severely impacted diagnosis, referral and treatment of kidney cancer at a tertiary referral centre. With a policy of prioritization and COVID-protected pathways, capacity for time-sensitive oncological interventions was maintained and no immediate clinical harm was observed.

Growth and renal function dynamics of renal oncocytomas in patients on active surveillance.

OBJECTIVES: To study the natural history of renal oncocytomas and address indications for intervention by determining how growth is associated with renal function over time, the reasons for surgery and ablation, and disease-specific survival. PATIENTS AND METHODS: The study was conducted in a retrospective cohort of consecutive patients with renal oncocytoma on active surveillance reviewed at the Specialist Centre for Kidney Cancer at the Royal Free London NHS Foundation Trust (2012 to 2019). Comparison between groups was performed using Mann-Whitney U-tests and chi-squared tests. A mixed-effects model with a random intercept for patient was used to study the longitudinal association between tumour size and estimated glomerular filtration rate (eGFR). RESULTS: Longitudinal data from 98 patients with 101 lesions were analysed. Most patients were men (68.3%) and the median (interquartile range [IQR]) age was 69 (13) years. The median (IQR) follow-up was 29 (26) months. Most lesions were small renal masses, and 24% measured over 4 cm. Over half (64.4%) grew at a median (IQR) rate of 2 (4) mm per year. No association was observed between tumour size and eGFR over time (P = 0.871). Nine lesions (8.9%) were subsequently treated. Two deaths were reported, neither were related to the diagnosis of renal oncocytoma. CONCLUSION: Natural history data from the largest active surveillance cohort of renal oncocytomas to date show that renal function does not seem to be negatively impacted by growing oncocytomas, and confirms clinical outcomes are excellent after a median follow-up of over 2 years. Active surveillance should be considered the 'gold standard' management of renal oncocytomas up to 7cm.

Outcomes of Renal Tumors Treated by Image-Guided Percutaneous Cryoablation: Immediate and 3- and 5-Year Outcomes at a Regional Center.

OBJECTIVE. The purpose of this study was to evaluate the immediate and 3- and 5-year outcomes of patients with clinical stage T1 (cT1) biopsy-proven renal cell carcinoma (RCC) treated by image-guided percutaneous cryoablation at a regional interventional oncology center. MATERIALS AND METHODS. A prospectively maintained local interventional radiology database identified patients with cT1 RCC lesions that were treated by percutaneous cryoablation. Technical success, procedural complications (graded using the Clavien-Dindo classification system), and the residual unablated tumor rate were collated. Local tumor progression-free survival was estimated using Kaplan-Meier estimates. RESULTS. A total of 180 patients with 185 separate cT1 RCC lesions were identified. Mean patient age was 68.4 years (range, 34.1-88.9 years) and 52 patients (28.9%) were women. There were 168 (90.8%) and 17 (9.2%) cT1a and cT1b lesions, respectively, with a mean lesion size of 28.5 mm (range, 11-58 mm). Technical success was achieved in 183 of 185 (98.9%) patients. The major complication rate (Clavien-Dindo classification ≥ grade III) was 2.2% (four out of 185). Residual unablated tumor on the first follow-up scan was identified in four of 183 tumors (2.2%). Estimated local tumor progression-free survival at 3 and 5 years was 98.3% and 94.9%, respectively. No distant metastases or deaths attributable to RCC occurred. Mean estimated glomerular filtration rate (eGFR) before the procedure was 72.4 ± 18.5 (SD) mL/min/1.73 m2 and this was not statistically significantly different after the procedure (69.7 ± 18.8 mL/min/1.73 m2), at 1 year (70.7 ± 16.4 mL/min/1.73 m2), or at 2 years (69.8 ± 18.9 mL/min/1.73 m2) (p > 0.05). CONCLUSION. These data add to the accumulating evidence that image-guided cryoablation is an efficacious treatment for selected cT1 RCC with a low complication rate and ro bust 3- and 5-year outcomes.

Distal corpus cavernosum fibrosis and erectile dysfunction secondary to non-ischaemic priapism.

Non-ischaemic priapism is a rare type of priapism and is associated with penile or perineal trauma. The absence of ischaemia should theoretically prevent smooth muscle necrosis and corporal fibrosis which occurs in ischaemic priapism. The aim of this study was to first report a patient series with non-ischaemic priapism that developed distal corpus cavernosum fibrosis and erectile dysfunction. Over a 5 year period, a cohort of 6 patients diagnosed with non-ischaemic priapism presented to a single centre. The diagnosis was based on a clinical history, penile examination with confirmation using a combination of cavernosal blood gas analysis, colour duplex ultrasonography of the penis and angiography. Patients were followed up in clinic at regular intervals with clinical examination and repeat imaging. Following a median follow up of 4 weeks (range 2-12) the patients reported either the development of erectile dysfunction with distal penile flaccidity. Five patients required the use of PDE-5 inhibitors to achieve full tumescence. The remaining patient eventually underwent insertion of a penile prosthesis due to the failure of pharmacotherapies. Based on these findings we suggest that superselective embolisation of non-ischaemic priapism cases occasionally should be performed after a shorter period of conservative treatment.

Review of the role of imaging in the diagnosis of priapism.

Imaging has a specific role in the diagnosis and management of priapism. The primary imaging modality is ultrasound with colour Doppler (CDUS) which can accurately assess the hemodynamics of the cavernosal arteries. This is particularly useful in equivocal cases and can help differentiate ischemic from non-ischemic priapism as well as confirm the presence and location of arterio-venous fistulae post penile trauma. Furthermore, CDUS is invaluable in the post treatment follow up of non-ischemic priapism. Contrast enhanced magnetic resonance imaging (MRI) can demonstrate the extent of cavernosal necrosis in ischemic priapism and in conjunction with computer tomography (CT) has an important role in excluding underlying malignancy. MRI and CT angiography are used to evaluate pudendal arterial anatomy, which can be extremely variable and aids in the management of non-ischemic priapism. In selected cases of non-ischemic priapism, catheter angiography and transcatheter embolization of arteriovenous fistulae is an effective treatment. This review will examine the specific roles of different imaging modalities in the subtypes of priapism as well as highlight some of the pitfalls encountered in imaging.

Therapeutic outcomes and analysis of Doppler findings in 25 patients with non-ischemic priapism.

Non-ischemic priapism (NiP) is painless partial tumescence caused by genital trauma and the formation of intracorporal arterio-venous fistula. This is a retrospective study of 25 men with NiP and reports the long-term erectile function and colour doppler ultrasound (CDUS) findings after treatment for NiP. Unstimulated CDUS was performed at diagnosis, 1 week and at last follow-up after treatment. CDUS traces were analysed: peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI) and mean velocity (MV) were calculated. Erectile function was assessed using the IIEF-EF questionnaire. At the last follow-up (median 24 months), 16 men had normal erectile function (64%): median IIEF-EF score 29 (IQR 28.5-30; σ2 2.78) and nine had erectile dysfunction (36%): median IIEF-EF score 17 (IQR 14-22; σ2 33.6). MV and EDV were statistically higher in those patients with erectile dysfunction at last follow-up compared to patients with normal erectile function: median MV 5.3 cm/s (IQR 2.4-10.5 cm/s; σ2 34) vs 2.95 cm/s (IQR 1.03-3.95; σ2 3.4) p < 0.002 and median EDV 4.0 cm/s (IQR 1.5-8.0; σ2 14.7) vs 0 cm/s (IQR 0-1.75; σ2 2.21) p < 0.004. Erectile dysfunction was observed in 36% of men treated for NiP and was associated with abnormal low resistance resting CDUS waveforms. Further investigation for persistent arteriovenous fistulation should be considered in these patients.

Renal mass biopsy - a practical and clinicopathologically relevant approach to diagnosis.

Advancements in imaging modalities have increased the frequency of renal mass discovery. Imaging has typically been considered sufficient to guide management for a large proportion of these tumours, but renal mass biopsies (RMBs) have an increasing role in determining malignancy and can be a valuable tool for preventing unnecessary surgery in patients with benign tumours. A structured approach should be used to help to navigate the expanding repertoire of renal tumours, many of which are molecularly defined. In terms of tumour subtyping, the pathologist's strategy should focus on stratifying patients into clinically different prognostic groups according to our current knowledge of tumour behaviour, including benign, low-grade or indolent, intermediate malignant or highly aggressive. Crucial pathological features and morphological mimicry of tumours can alter the tumour's prognostic group. Thus, pathologists and urologists can use RMB to select patients with tumours at a reduced risk of progression, which can be safely managed with active surveillance within a tailored imaging schedule, versus tumours for which ablation or surgical intervention is indicated. RMB is also crucial in the oncological setting to distinguish between different high-grade tumours and guide tailored management strategies.

Nephron Sparing Treatment (NEST) for Small Renal Masses: A Feasibility Cohort-embedded Randomised Controlled Trial Comparing Percutaneous Cryoablation and Robot-assisted Partial Nephrectomy.

There is a paucity of high-level evidence on small renal mass (SRM) management, as previous classical randomised controlled trials (RCTs) failed to meet accrual targets. Our objective was to assess the feasibility of recruitment to a cohort-embedded RCT comparing cryoablation (CRA) to robotic partial nephrectomy (RPN). A total of 200 participants were recruited to the cohort, of whom 50 were enrolled in the RCT. In the CRA intervention arm, 84% consented (95% confidence interval [CI] 64-95%) and 76% (95% CI 55-91%) received CRA; 100% (95% CI 86-100%) of the control arm underwent RPN. The retention rate was 90% (95% CI 79-96%) at 6 mo. In the RPN group 2/25 (8%) were converted intra-operative to radical nephrectomy. Postoperative complications (Clavien-Dindo grade 1-2) occurred in 12% of the CRA group and 29% of the RPN group. The median length of hospital stay was shorter for CRA (1 vs 2 d; p = 0.019). At 6 mo, the mean change in renal function was -5.0 ml/min/1.73 m2 after CRA and -5.8 ml/min/1.73 m2 after RPN. This study demonstrates the feasibility of a cohort-embedded RCT comparing CRA and RPN. These data can be used to inform multicentre trials on SRM management. PATIENT SUMMARY: We assessed whether patients with a small kidney tumour would consent to a trial comparing two different treatments: cryoablation (passing small needles through the skin to freeze the kidney tumour) and surgery to remove part of the kidney. We found that most patients agreed and a full trial would therefore be feasible.

Oncological and Peri-Operative Outcomes of Percutaneous Cryoablation of Renal Cell Carcinoma for Patients with Hereditary RCC Diseases-An Analysis of European Multi-Centre Prospective EuRECA Registry.

This study aims to evaluate the safety, efficacy, and renal function preservation of percutaneous cryoablation (PCA) for small renal masses (SRMs) in inherited RCC syndromes. Patients with inherited T1N0M0 RCCs (<7 cm) undergoing PCA from 2015 to 2021 were identified from the European Registry for Renal Cryoablation (EuRECA). The primary outcome was local recurrence-free survival (LRFS). The secondary outcomes included technical success, peri-operative outcomes, and other oncological outcomes estimated using the Kaplan-Meier method. Simple proportions, chi-squared tests, and t-tests were used to analyse the peri-operative outcomes. A total of 68 sessions of PCA were performed in 53 patients with RCC and 85 tumours were followed-up for a mean duration of 30.4 months (SD ± 22.0). The overall technical success rate was 99%. The major post-operative complication rate was 1.7%. In total, 7.4% (2/27) of patients had >25% reduction in renal function. All oncological events were observed in VHL patients. Estimated 5-year LRFS, metastasis-free survival, cancer-specific survival, and overall survival were 96.0% (95% CI 75-99%), 96.4% (95% CI 77-99%), 90.9% (95% CI 51-99%), and 90.9% (95% CI 51-99%), respectively. PCA of RCCs for patients with hereditary RCC SRMs appears to be safe, offers low complication rates, preserves renal function, and achieves good oncological outcomes.

Epitheloid Angiomyolipomas of the Kidney: Rare Renal Tumors Associated With Poor Prognoses.

OBJECTIVE: To demonstrate the clinical spectrum and challenges associated with clinical management of epitheloid angiomyolipomas (eAML). METHODS: We retrospectively reviewed the surgical database of a high-volume tertiary kidney cancer center from 2015 to 2020 to identify cases with a final histological diagnosis of eAML. Descriptive analysis of all cases was conducted. RESULTS: Five surgical cases of eAMLs were identified. Two of which have had no tumor recurrence since surgery, and three patients passed away due to disease progression. CONCLUSION: eAML are rare renal tumors which the World Health Organisation (5th Edition, 2022) and International Classification of Diseases for Oncology classify as having unspecified, borderline, or uncertain behavior. Here, we report that can also demonstrate aggressive behavior with fatal consequences. Post-operative follow-up should be recommended for all, with shorter intervals for patients with poor prognostic factors.

In-Circuit High-Frequency Jet Ventilation for Radiological Tumor Ablation: A Case Series.

High-frequency jet ventilation (HFJV) can reduce organ movement that otherwise complicates percutaneous image-guided ablation (IGA) procedures. This study describes feasibility and safety of the technique in routine use. We describe our method for the use of HFJV and present 169 consecutive cases, including IGA of tumors of the lung, liver, kidney, and pancreas. Intended oncological treatment was delivered in all cases and HFJV used for the duration of treatment in all except one case. We describe the characteristics of patients, procedures, and adverse events. It is feasible to use HFJV as the routine standard of care for IGA.

Differences in polysomnographic, nocturnal penile tumescence and penile doppler ultrasound findings in men with stuttering priapism and sleep-related painful erections.

Men with Stuttering Priapism (SP) and sleep-related painful erections (SRPE) experience bothersome nocturnal painful erections resulting in poor sleep. The aim of this study is to observe common features and differences between men with SP and SRPE based on polysomnography, nocturnal penile tumescence (NPT), and penile doppler ultrasound (PDU). This is a prospective cohort study of 20 participants divided into two groups (Group 1 = SP [n = 12]; Group 2 = SRPE [n = 8]) with bothersome painful nocturnal erections. All participants were referred to the sleep disorder clinic to be assessed and consented for overnight polysomnography with simultaneous NPT recording and to complete validated sleep, sexual dysfunction and health-related quality of life questionnaires. Unstimulated PDU was also performed. Abnormal Polysomnographic findings (reduced sleep efficiency, total sleep time, and awake after sleep onset) were identified in both groups suggesting poor sleep. Men with SP had significantly longer erections (60.0 vs 18.5; p = 0.002) and took longer to detumesce once awake (25.7 vs 5.4 min; p = 0.001) than men with SRPE. They also had significantly higher peak systolic and end diastolic velocities on unstimulated PDU with an abnormal low resistance waveform identified. No sleep pathology was identified in men with SP. This implies a local (penile) etiology in men with SP. Men with SRPE had a normal resting PDU and abnormal sleep architecture with REM awakenings and significantly more Periodic limb movements (p = 0.04) than men with SP suggesting a central (sleep-related) cause in men with SRPE. Sexual dysfunction and poor HR-QoL was identified on validated questionnaires in both groups. SP and SRPE are rare entities that share similar symptoms (painful nocturnal erections and poor sleep) but dissimilar features of nocturnal erection onset, duration and resolution with different polysomnographic features which may allude to a different pathophysiology.

Renal cryoablation - a practical guide for interventional radiologists.

Renal cryoablation is a treatment option for early stage renal cell carcinomas with excellent oncological outcomes and low morbidity. This review outlines the technique of renal cryoablation and provides a guide for interventional radiologists on setting up an integrated service within a renal cancer network multidisciplinary setting. Patient selection and preparation, together with the technical aspects which ensure optimal oncological outcomes and avoid collateral damage to adjacent organs are highlighted.

Splenogonadal fusion: A rare paratesticular lesion and how to recognise it on ultrasound.

INTRODUCTION: Splenogonadal fusion is a rare developmental disorder that results in a gonadal or paragonadal mass due to the close proximity of the developing spleen and gonad. CASE REPORT: We describe a case of splenogonadal fusion presenting as a paratesticular mass in a 25-year-old male. This was ultimately diagnosed on surgical biopsy. DISCUSSION: Splenogonadal fusion is a rare abnormality but can be managed conservatively. The sonographic features and the differential diagnosis are highlighted. CONCLUSION: Through this case, we highlight the clinical and sonographic features of splenogonadal fusion. Awareness amongst ultrasound practitioners is important, given that it can be managed conservatively, and means of a non-invasive diagnosis are highlighted.

Protocol for a feasibility study of a cohort embedded randomised controlled trial comparing NEphron Sparing Treatment (NEST) for small renal masses.

INTRODUCTION: Small renal masses (SRMs; ≤4 cm) account for two-thirds of new diagnoses of kidney cancer, the majority of which are incidental findings. The natural history of the SRM seems largely indolent. There is an increasing concern regarding surgical overtreatment and the associated health burden in terms of morbidity and economy. Observational data support the safety and efficacy of percutaneous cryoablation but there is an unmet need for high-quality evidence on non-surgical management options and a head-to-head comparison with standard of care is lacking. Historical interventional trial recruitment difficulties demand novel study conduct approaches. We aim to assess if a novel trial design, the cohort embedded randomised controlled trial (RCT), will enable carrying out such a comparison. METHODS AND ANALYSIS: Single-centre prospective cohort study of adults diagnosed with SRM (n=200) with an open label embedded interventional RCT comparing nephron sparing interventions. Cohort participants will be managed at patient and clinicians' discretion and agree with longitudinal clinical data and biological sample collection, with invitation for trial interventions and participation in comparator control groups. Cohort participants with biopsy-proven renal cell carcinoma eligible for both percutaneous cryoablation and partial nephrectomy will be randomly selected (1:1) and invited to consider percutaneous cryoablation (n=25). The comparator group will be robotic partial nephrectomy (n=25). The primary outcome of this feasibility study is participant recruitment. Qualitative research techniques will assess barriers and recruitment improvement opportunities. Secondary outcomes are participant trial retention, health-related quality of life, treatment complications, blood transfusion rate, intensive care unit admission and renal replacement requirement rates, length of hospital stay, time to return to pre-treatment activities, number of work days lost, and health technologies costs. ETHICS AND DISSEMINATION: Ethical approval has been granted (UK HRA REC 19/EM/0004). Study outputs will be presented and published. TRIAL REGISTRATION: ISRCTN18156881; Pre-results.

High-Frequency Jet Ventilation During Cryoablation of Small Renal Tumours.

AIM: To evaluate the effect of high-frequency jet ventilation (HFJV) in place of standard intermittent positive-pressure ventilation (IPPV) on procedure duration, patient radiation dose, complication rates, and outcomes during CT-guided cryoablation of small renal tumours. MATERIALS AND METHODS: One hundred consecutive CT-guided cryoablation procedures to treat small renal tumours under general anaesthesia were evaluated-50 with standard IPPV and 50 after the introduction of HFJV as standard practice. Anaesthesia and procedural times, ionising radiation dose, complications, and 1-month post-treatment outcomes were collected. RESULTS: HFJV was feasible and safe in all cases. Mean procedure time and total anaesthetic time were shorter with HFJV (p = <0.0001). The number of required CT acquisitions (p = 0.0002) and total procedure patient radiation dose (p = 0.0027) were also lower in the HFJV group compared with the IPPV group. There were a total of four complications of Clavien-Dindo classification 3 or above-three in the IPPV group and one in the HFJV group. At 1-month follow-up, two cases (both in the IPPV group) demonstrated subtotal treatment. Both cases were subsequently successfully retreated with cryoablation. CONCLUSION: By reducing target tumour motion during CT-guided renal cryoablation, HFJV can reduce procedure times and exposure to ionising radiation. HFJV provides an important adjunct to complex image-guided interventions, with potential to improve safety and treatment outcomes.