Tze M. Wah

Radiofrequency ablation (RFA) of renal cell carcinoma (RCC): experience in 200 tumours

To evaluate our clinical experience with percutaneous image‐guided radiofrequency ablation (RFA) of 200 renal tumours in a large tertiary referral university institution.

Protecting the Ureter during Radiofrequency Ablation of Renal Cell Cancer: A Pilot Study of Retrograde Pyeloperfusion with Cooled Dextrose 5% in Water

PURPOSE To describe early experience with cooled dextrose 5% in water (D5W) solution retrograde pyeloperfusion during radiofrequency (RF) ablation of renal cell carcinoma (RCC) within 1.5 cm of the ureter with respect to feasibility, safety, and incidence of residual/recurrent tumor in proximity to the cooled collecting system. MATERIALS AND METHODS Between November 2004 and April 2007, 17 patients underwent 19 RF ablation sessions of RCCs within 1.5 cm of the ureter during cooled D5W pyeloperfusion (nine men, eight women; mean tumor size, 3.5 cm; mean age, 73 y; mean distance to ureter, 7 mm). RF ablation was performed with pulsed impedance control current. The records and imaging studies of patients treated with this technique were reviewed for demographics, indication, technique, complications, and tumor recurrence. RESULTS All 19 RF ablation and ureteral catheter placement procedures were technically successful. No patient developed a ureteral stricture or hydronephrosis during a mean of 14 months of follow-up (range, 4-32 months). Three patients had residual tumor on the first follow-up imaging study, but all three tumors were completely ablated after a second RF ablation session. No complications or deaths occurred. No recurrent tumor was seen anywhere in the treated tumors, and there was complete ablation of the tumor margin in proximity to the collecting system. CONCLUSIONS RF ablation of RCC within 1.5 cm of the ureter is feasible with cooled D5W retrograde pyeloperfusion and is not associated with reduced efficacy, ureteral injury, or early recurrence.

Initial Experience with the Resonance Metallic Stent for Antegrade Ureteric Stenting

Background and purposeWe describe our initial experience with a new metallic ureteric stent which has been designed to provide long-term urinary drainage in patients with malignant ureteric strictures. The aim is to achieve longer primary patency rates than conventional polyurethane ureteric stents, where encrustation and compression by malignant masses limit primary patency. The Resonance metallic double-pigtail ureteric stent (Cook, Ireland) is constructed from coiled wire spirals of a corrosion-resistant alloy designed to minimize tissue in-growth and resist encrustation, and the manufacturer recommends interval stent change at 12 months.MethodsSeventeen Resonance stents were inserted via an antegrade approach into 15 patients between December 2004 and March 2006. The causes of ureteric obstruction were malignancies of the bladder (n = 4), colon (n = 3), gynecologic (n = 5), and others (n = 3).ResultsOne patient had the stent changed after 12 months, and 3 patients had their stents changed at 6 months. These stents were draining adequately with minimal encrustation. Four patients are still alive with functioning stents in situ for 2–10 months. Seven patients died with functioning stents in place (follow-up periods of 1 week to 8 months). Three stents failed from the outset due to bulky pelvic malignancy resulting in high intravesical pressure, as occurs with conventional plastic stents.ConclusionOur initial experience with the Resonance metallic ureteric stent indicates that it may provide adequate long-term urinary drainage (up to 12 months) in patients with malignant ureteric obstruction but without significantly bulky pelvic disease. This obviates the need for regular stent changes and would offer significant benefit for these patients with limited life expectancy.

Radiofrequency Ablation of a Central Renal Tumor: Protection of the Collecting System with a Retrograde Cold Dextrose Pyeloperfusion Technique

Renal radiofrequency (RF) ablation therapy is a safe and effective therapy for small renal cell carcinoma. Although the risk of complications is low, the potential for ureteral or calyceal injury does increase in the case of a centrally located lesion. A retrograde cold dextrose pyeloperfusion technique was designed to protect the collecting system in a patient who underwent percutaneous RF ablation of a central tumor of the left kidney.

The STAR trial protocol: a randomised multi-stage phase II/III study of Sunitinib comparing temporary cessation with allowing continuation, at the time of maximal radiological response, in the first-line treatment of locally advanced/metastatic Renal Cancer

BackgroundOver recent years a number of novel therapies have shown promise in advanced renal cell carcinoma (RCC). Internationally the standard of care of first-line therapy is sunitinib™, after a clear survival benefit was demonstrated over interferon-α. Convention dictates that sunitinib is continued until evidence of disease progression, assuming tolerability, although there is no evidence that this approach is superior to intermittent periods of treatment. The purpose of the STAR trial is to compare the standard treatment strategy (conventional continuation strategy, CCS) with a novel drug free interval strategy (DFIS) which includes planned treatment breaks.Methods/DesignThe STAR trial is an NIHR HTA-funded UK pragmatic randomised phase II/III clinical trial in the first-line treatment of advanced RCC. Participants will be randomised (1:1) to either a sunitinib CCS or a DFIS. The overall aim of the trial is to determine whether a DFIS is non-inferior, in terms of 2-year overall survival (OS) and quality adjusted life years (QALY) (averaged over treatment and follow up), compared to a CCS. The QALY primary endpoint was selected to assess whether any detriment in terms of OS could be balanced with improvements in quality of life (QoL). This is a complex trial with a number of design challenges, and to address these issues a feasibility stage is incorporated into the trial design. Predetermined recruitment (stage A) and efficacy (stage B) intermediary endpoints must be met to allow continuation to the overall phase III trial (stage C). An integral qualitative patient preference and understanding study will occur alongside the feasibility stage to investigate patients’ feelings regarding participation or non-participation in the trial.DiscussionThe optimal duration of continuing sunitinib in advanced RCC is unknown. Novel targeted therapies do not always have the same constraints to treatment duration as standard chemotherapeutic agents and currently there are no randomised data comparing different treatment durations. Incorporating planned treatment breaks has the potential to improve QoL and cost effectiveness, hopefully without significant detriment on OS, as has been demonstrated in other cancer types with other treatments.Trial RegistrationControlled-trials.com ISRCTN 06473203

Infectious Complications after Percutaneous Radiofrequency Ablation of Renal Cell Carcinoma in Patients with Ileal Conduit

Percutaneous renal radiofrequency (RF) ablation is a safe and minimally invasive treatment for renal cell carcinoma. The most common minor complications are pain, self-limiting hematuria, and postablation syndrome. Major complications are rare and include significant hemorrhage and thermal injury to the ureter. Reports of infectious complications after ablation are uncommon, but increased risks in patients with ileal conduits have been reported. The present report describes two patients with ileal conduits who underwent percutaneous renal RF ablation and developed infectious complications (a renal abscess and a calyceal-cutaneous fistula) despite prophylactic antibiotic treatment.

Unenhanced CT for the evaluation of acute ureteric colic: the essential pictorial guide

Acute ureteric colic is a common emergency, often dealt with by the emergency physician or general practitioner and referred on to the urologist. Unenhanced CT of the kidneys, ureters and bladder (CTKUB) is the ‘gold standard’ imaging investigation for establishing a diagnosis and guiding management. An appreciation of the CTKUB signs, which support or refute a diagnosis of ureteric colic, is highly valuable to the clinician when making a urological referral, and to the urologist, who must make appropriate management plans. All salient diagnostic and supportive features of ureteric colic are carefully illustrated, as are important radiological mimics, with the objectives of educating and informing the non-radiologist. Ready access to the picture archive and communication system (PACS) allows all specialists involved to interpret the radiological report with the benefit of images. A stone within the ureter may not always be readily apparent. Soft tissue rim sign around a calcific focus is an important indicator of a ureteric stone, whereas a comet tail sign suggests a phlebolith (a calcified venous thrombosis), a radiological mimic of a ureteric stone. Numerous secondary signs of ureteric obstruction may be present including hydronephrosis and perinephric stranding, and can help to confirm the diagnosis. The relative diagnostic weighting of signs is discussed, and a checklist is provided to assist with interpretation. Unexpected alternative radiological diagnoses are also illustrated, which may have significant management consequences necessitating specialist referral.

Acute Tubular Necrosis Following Radiofrequency Ablation of a Renal Cell Carcinoma

We described a case of acute tubular necrosis in a patient with a renal cell carcinoma in a solitary kidney following renal RFA.