Features reported after exposure to automatic dishwashing rinse aids.

INTRODUCTION: Automatic dishwashing rinse aids are drying aids which contain non-ionic surfactants, usually ethoxylated alcohols, typically at concentrations of ≤30%. OBJECTIVE: To assess the reported toxicity of rinse aids. METHODS: Telephone enquiries to the UK National Poisons Information Service were analysed from January 2008 to June 2019. RESULTS: Ingestion: Ingestion was involved in 976 cases and produced gastrointestinal features, coughing and central nervous system depression, particularly in young children. In those in whom the amount ingested was known, the majority (56%) of children <18 years and of adults (57%) ingested <50 mL of rinse aid. Although moderate or severe exposures (Poisoning Severity Score (PSS) ≥ 2) were uncommon, they occurred significantly (p < 0.0008) more often in adults (9.0%) than in children (1.8%); however, three of the four adults with PSS ≥ 2 co-ingested other substances. Eye exposure: Ocular exposure was reported in 35 cases, of whom 29 developed features. Eye irritation (n = 10, 28.6%) and eye pain (n = 10, 28.6%) were reported most commonly, and three patients (8.6%) developed corneal abrasions (PSS 2). Dermal exposure: Thirty-four patients were exposed dermally, and six (17.6%) reported features, including rash, numbness, pruritus and burns (PSS 1). CONCLUSIONS: Overall, clinical features developed in 47% of patients exposed to rinse aids, but more severe features (PSS ≥ 2) were rare (<3%) following exposure by any route.

Toxicity of traditional and soluble film automatic dishwashing tablets.

INTRODUCTION: Detergents used in automatic dishwashing machines are of two main types: traditional tablets that require removal from an external wrapper and newer soluble film tablets. OBJECTIVE: To determine the toxicity of automatic dishwashing tablets. METHODS: Telephone enquiries to the UK National Poisons Information Service were analysed for the period January 2008 to June 2019. RESULTS: Ingestion: Ingestion was involved in 798 traditional tablet exposures and 725 soluble film exposures. Clinical features (Poisoning Severity Score ≥ 1) developed in 22.2% of patients ingesting traditional tablets and in 28.8% ingesting soluble film tablets; moderate or severe toxicity was rare (<0.5% for both traditional and soluble film tablets). Children (≤5 years) significantly (p < 0.0001) more often developed features following ingestion of soluble film (n = 193, 28.2%) than traditional tablets (n = 134, 19.1%). In contrast, adults more often developed features following ingestion of traditional than soluble film tablets, although this difference was not statistically significant. Eye exposure: The eye was involved in only 26 of 1539 exposures; 17 of 26 exposures resulted in ocular features. The most commonly reported features were conjunctivitis, eye pain and blurred vision, although one patient sustained a corneal abrasion and developed loss of vision. Skin exposure: Thirty-four of 1539 exposures involved the skin but only 3 developed dermal features which were minor. CONCLUSIONS: Children (≤5 years) significantly more often developed features following ingestion of soluble film than traditional tablets, although the likelihood of a child developing features was relatively low (<30%) and features that did develop were almost always mild. In contrast, adults more often developed features following the ingestion of traditional than soluble film tablets. Overall, the eye was involved in only 1.7% of exposures and only one patient sustained a corneal abrasion.

Sir Winston Churchill: treatment for pneumonia in 1943 and 1944.

This paper reviews Churchill's illnesses in February 1943 and August/September 1944 when he developed pneumonia; on the first occasion this followed a cold and sore throat. Churchill was managed at home by Sir Charles Wilson (later Lord Moran) with the assistance of two nurses and the expert advice of Dr Geoffrey Marshall, Brigadier Lionel Whitby and Colonel Robert Drew. A sulphonamide (sulphathiazole on the first occasion) was prescribed for both illnesses. Churchill recovered, and despite his illnesses continued to direct the affairs of State from his bed. On the second occasion, Churchill's illness was not made public.

In Carthage ruins: the illness of Sir Winston Churchill at Carthage, December 1943.

This paper reviews Churchill's illness in Carthage in December 1943. It was characterised by fever that lasted 6 days, left lower lobe pneumonia and two episodes of atrial fibrillation. He was managed in a private villa by Lord Moran, his personal physician, with the assistance of two nurses and the expert advice of colleagues. Sulphadiazine and digitalis leaf were prescribed and Churchill recovered. It is remarkable that, despite the severity of his illness, he continued to direct the affairs of State from his bed.

Taking stock: UK national antidote availability increasing, but further improvements are required.

BACKGROUND: A 2010/2011 audit of the Royal College of Emergency Medicine (RCEM) National Poisons Information Service (NPIS) UK guidelines on antidote availability demonstrated variable stocking of antidotes for the management of poisoned patients; the guidelines were updated and republished in 2013. AIM: To assess if antidote stocking has improved since the 2010/2011 audit and introduction of the 2013 guidelines. METHODS: Questionnaires were sent to Chief Pharmacists at all 215 acute hospitals in England, Wales and Northern Ireland in October 2014. Data were collected on the timing of availability (category A antidotes should be available immediately, category B within 1 h and category C can be held supraregionally) and stock levels. RESULTS: 169 (78.6%) responses were received. Atropine, calcium gluconate and flumazenil (category A) were the only antidotes available in all hospitals within the recommended time and stock levels. Forty-one (24.3%) hospitals held every category A antidote; this increased to 81 (47.9%) for those holding at least one cyanide antidote and all other category A antidotes. The proportion of hospitals stocking category A/B antidotes within the recommended time increased for 20 (90.9%) category A/B antidotes. Fomepizole (category B) availability increased to 62.1% of hospitals from 11.4% in 2010/2011. Other than penicillamine (63.3% hospitals), there was poor availability (2.4%-36.1%) of category C antidotes. CONCLUSIONS: Availability of category A and B antidotes has improved since the 2010/2011 audit and 2013 guidelines. However, there remains significant variability particularly for category C antidotes. More work is required to ensure that those treating poisoned patients have timely access to antidotes focusing particularly on category C antidotes.

Quantitative analysis of technological innovation in minimally invasive surgery.

BACKGROUND: In the past 30 years surgical practice has changed considerably owing to the advent of minimally invasive surgery (MIS). This paper investigates the changing surgical landscape chronologically and quantitatively, examining the technologies that have played, and are forecast to play, the largest part in this shift in surgical practice. METHODS: Electronic patent and publication databases were searched over the interval 1980-2011 for ('minimally invasive' OR laparoscopic OR laparoscopy OR 'minimal access' OR 'key hole') AND (surgery OR surgical OR surgeon). The resulting patent codes were allocated into technology clusters. Technology clusters referred to repeatedly in the contemporary surgical literature were also included in the analysis. Growth curves of patents and publications for the resulting technology clusters were then plotted. RESULTS: The initial search revealed 27,920 patents and 95,420 publications meeting the search criteria. The clusters meeting the criteria for in-depth analysis were: instruments, image guidance, surgical robotics, sutures, single-incision laparoscopic surgery (SILS) and natural-orifice transluminal endoscopic surgery (NOTES). Three patterns of growth were observed among these technology clusters: an S-shape (instruments and sutures), a gradual exponential rise (surgical robotics and image guidance), and a rapid contemporaneous exponential rise (NOTES and SILS). CONCLUSION: Technological innovation in MIS has been largely stagnant since its initial inception nearly 30 years ago, with few novel technologies emerging. The present study adds objective data to the previous claims that SILS, a surgical technique currently adopted by very few, represents an important part of the future of MIS.

Isopropanol poisoning.

INTRODUCTION: Isopropanol is a clear, colorless liquid with a fruity odor and a mild bitter taste. Most commonly found domestically as rubbing alcohol, isopropanol is also found in numerous household and commercial products including cleaners, disinfectants, antifreezes, cosmetics, solvents, inks, and pharmaceuticals. AIM: The aim of this review is to critically review the epidemiology, toxicokinetics, mechanisms of toxicity, clinical features, diagnosis, and management of isopropanol poisoning. METHODS: OVID MEDLINE and ISI Web of Science were searched to November 2013 using the words "isopropanol", "isopropyl alcohol", "2-propanol", "propan-2-ol", and "rubbing alcohol" combined with the keywords "poisoning", "poison", "toxicity", "ingestion", "adverse effects", "overdose", or "intoxication". These searches identified 232 citations, which were then screened via their abstract to identify relevant articles referring specifically to the epidemiology, toxicokinetics, mechanisms of toxicity, clinical features, diagnosis, and management of isopropanol poisoning; 102 were relevant. Further information was obtained from book chapters, relevant news reports, and internet resources. These additional searches produced eight non-duplicate relevant citations. EPIDEMIOLOGY: The majority of isopropanol exposures are unintentional and occur in children less than 6 years of age. Although isopropanol poisoning appears to be a reasonably common occurrence, deaths are rare. TOXICOKINETICS: Isopropanol is rapidly absorbed following ingestion with peak plasma concentrations occurring within 30 min. It can also be absorbed following inhalation or dermal exposure. Isopropanol is widely distributed with a volume of distribution of 0.45-0.55 L/kg. Isopropanol is metabolized by alcohol dehydrogenase to acetone, acetol and methylglyoxal, propylene glycol, acetate, and formate with conversion of these metabolites to glucose and other products of intermediary metabolism. The elimination of isopropanol is predominantly renal, though some pulmonary excretion of isopropanol and acetone occurs. In one case 20% of the absorbed dose was eliminated unchanged in urine, with the remainder excreted as acetone and metabolites of acetone. The elimination half-life of isopropanol is between 2.5 and 8.0 h, whereas elimination of acetone is slower with a half-life following isopropanol ingestion of between 7.7 and 27 h. MECHANISMS OF TOXICITY: While the exact mechanism of action of isopropanol has not been fully elucidated, brain stem depression is thought to be the predominant mechanism. While the clinical effects are thought to be mostly due to isopropanol, acetone may also contribute. CLINICAL FEATURES: The major features of severe poisoning are due to CNS and respiratory depression, shock, and circulatory collapse. The most common metabolic effects are an increased osmol (osmolal) gap, ketonemia, and ketonuria. Diagnosis. Poisoning can be diagnosed using the measurement of isopropanol serum concentrations, though these may not be readily available. Diagnosis is therefore more typically made on the basis of the patient's history and clinical presentation. An osmol gap, ketonemia, and/or ketonuria without metabolic acidosis, along with a fruity or sweet odor on the breath and CNS depression support the diagnosis. Management. Supportive care is the mainstay of management with primary emphasis on respiratory and cardiovascular support. Hemodialysis enhances elimination of isopropanol and acetone and should be considered in very severe poisoning. CONCLUSIONS: Severe isopropanol poisoning results in CNS and respiratory depression and circulatory collapse. Treatment primarily consists of symptom-directed supportive care. Although hemodialysis increases the elimination of isopropanol and acetone substantially, it should only be considered in severe life-threatening poisonings. Patients usually make a full recovery provided they receive prompt supportive care.

National toxicovigilance for pesticide exposures resulting in health care contact - An example from the UK's National Poisons Information Service.

BACKGROUND: Although there are extensive systems in place for pharmacovigilance, similar systems for detecting adverse health effects relating to pesticide exposure are rare. In 2004, the National Poisons Information Service (NPIS) pesticide surveillance study was implemented to identify cases requiring health care contact in the UK. This report describes the epidemiology of pesticide exposures reported to poison centres in the UK over a 9-year period. METHODS: Data on exposures were gathered through monitoring access to the NPIS's online clinical toxicology database TOXBASE(®) and through monitoring calls to the four NPIS units (Edinburgh, Cardiff, Newcastle and Birmingham). Severity was judged by both caller and NPIS staff. RESULTS: During the 9 years, 34,092 enquiries concerning pesticides were recorded; 7,804 cases of pesticide exposure were derived from these enquiries. Exposures were predominantly unintentional and acute (6,789; 87.0%); 217 (2.8%) and 755 (9.7%) were chronic unintentional and acute deliberate self-harm exposures, respectively. The majority of cases occurred in children, especially the 0-4 year age group The minimum incidence of pesticide exposure requiring health care contact was 2.0 cases/100,000 population per year. Reported numbers were 6- to 25-fold greater than those picked up through other UK pesticide toxicovigilance schemes. There were 81 cases of severe toxicity and 38 cases of fatal exposure. Deliberate self-harm accounted for 62.3% of severe cases and 79% of deaths. Aluminium phosphide, paraquat, diquat and glyphosate were responsible for most severe and fatal cases. CONCLUSIONS: The data gathered from this pesticide surveillance study indicate that poison centre resources can usefully monitor pesticide exposures resulting in health care contact in the UK. The NPIS may usefully be one component of the UK's response to European legislation requiring surveillance of complications resulting from pesticide use.

Guidelines for laboratory analyses for poisoned patients in the United Kingdom.

To enable consistency of investigation and the establishment of best practice standards, consensus guidelines were formulated previously by the UK National Poisons Information Service and the Association for Clinical Biochemistry. These joint guidelines have now been updated to reflect current best practice. The types of laboratory investigation required for poisoned patients are categorized as either (a) essential common laboratory investigations or (b) specific toxicological assays, and also as either (i) common or (ii) specialist or infrequent. Tests in categories (a) and (bi) should be available 24 hours per day, with a maximum turnaround time of 2 h. For the specialist assays, i.e. category (bii), availability and turnaround times have been specified individually. The basis for selection of these times has been clinical utility. The adoption of these guidelines, along with the use of the National Poisons Information Service (0844 8920111) and its online poisons information resource TOXBASE(®) (www.toxbase.org) enable the poisoned patient to receive appropriate, 'best practice' investigations according to their clinical needs and will avoid unnecessary investigations.

Robotic prostatectomy: the first UK experience.

BACKGROUND: We describe a teamwork approach to setting up the UK's first clinical programme for robotically assisted laparoscopic radical prostatectomy. METHODS: On 22 November 2004 the Imperial Robotic Urological Surgery Group performed their first robotically assisted prostatectomy. Robotically assisted prostatectomy lends itself to division into eight definable stages. A team of four consultant urological surgeons utilized a structured rotating system, using these stages, for time at the console and tableside assisting. Fluidity of surgery was maintained by a surgeon acting as the tableside assistant for the stage prior to moving to the console. Data was collected prospectively for the first 50 cases and parameters associated with the learning curve compared to other reported series. RESULTS: Median operative time of 369.5 mins, median blood loss of 700 ml, with 12% of patients requiring a blood transfusion. Four patients required conversion to an open procedure; one resulting from equipment failure and three due to failure of progression. Four patients had an anastomotic leak with resulting ileus and two patients sustained rectal injuries, which were repaired intraoperatively using the robot. Median hospital stay was 4 days with a 22% positive surgical margin rate. CONCLUSION: Parameters indicative of the learning curve are comparable to existing published initial series of other robotic centres. The use of teamwork has enabled us to provide safe and time-efficient training for four surgeons simultaneously. The structured approach used in this setting demonstrates that urological surgeons of varying laparoscopic experience can acquire the skills necessary to competently perform laparoscopic radical prostatectomy.

Changes in standard of candidates taking the MRCP(UK) Part 1 examination, 1985 to 2002: analysis of marker questions.

BACKGROUND: The maintenance of standards is a problem for postgraduate medical examinations, particularly if they use norm-referencing as the sole method of standard setting. In each of its diets, the MRCP(UK) Part 1 Examination includes a number of marker questions, which are unchanged from their use in a previous diet. This paper describes two complementary studies of marker questions for 52 diets of the MRCP(UK) Part 1 Examination over the years 1985 to 2001 to assess whether standards have changed. METHODS: Study 1, which used routinely collected information on the performance of 4405 marker items, used a statistical method to assess changes in performance across diets. Study 2 compared performances of individual candidates on 28 individual marker items that were shared by the 1996/2 and 2001/3 diets. RESULTS: Study 1 found evidence that candidate performance on the MRCP(UK) Part 1 Examination showed a gradual improvement over the period 1985 to 1997, which was followed by a sharp decline in performance until 2001. The 'dog-leg' in performance at 1997/3 was not an artefact of changed Examination Regulations, mix of UK and overseas candidates, or time from qualification until taking the Examination. Study 2 confirmed that performance in 2001/3 was significantly worse than in 1996/3, that the poorer performance was found in graduates of UK medical schools, and that candidates passing the Examination in 2001/3 performed less well than those passing in 1996/2. CONCLUSION: There has been a decline in the performance of graduates from UK medical schools taking the MRCP(UK) Part 1 examination. The reasons for this are not clear, but the finding has implications for medical education, and further studies are needed of performance in other postgraduate and undergraduate examinations. The use of norm-referencing as the sole method for setting the pass mark over this period meant that candidates passing the MRCP(UK) examination also had a lower standard. The MRCP(UK) Part 1 and Part 2 examinations now have their standard set by criterion-referencing.

Position paper: Single-dose activated charcoal.

Single-dose activated charcoal therapy involves the oral administration or instillation by nasogastric tube of an aqueous preparation of activated charcoal after the ingestion of a poison. Volunteer studies demonstrate that the effectiveness of activated charcoal decreases with time. Data using at least 50 g of activated charcoal, showed a mean reduction in absorption of 47.3%, 40.07%, 16.5% and 21.13%, when activated charcoal was administered at 30 minutes, 60 minutes, 120 minutes and 180 minutes, respectively, after dosing. There are no satisfactorily designed clinical studies assessing benefit from single-dose activated charcoal to guide the use of this therapy. Single-dose activated charcoal should not be administered routinely in the management of poisoned patients. Based on volunteer studies, the administration of activated charcoal may be considered if a patient has ingested a potentially toxic amount of a poison (which is known to be adsorbed to charcoal) up to one hour previously. Although volunteer studies demonstrate that the reduction of drug absorption decreases to values of questionable clinical importance when charcoal is administered at times greater than one hour, the potential for benefit after one hour cannot be excluded. There is no evidence that the administration of activated charcoal improves clinical outcome. Unless a patient has an intact or protected airway, the administration of charcoal is contraindicated. A review of the literature since the preparation of the 1997 Single-dose Activated Charcoal Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

Position Paper on urine alkalinization.

This Position Paper was prepared using the methodology agreed by the American Academy of Clinical Toxicology (AACT) and the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT). All relevant scientific literature was identified and reviewed critically by acknowledged experts using set criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not considered. A draft Position Paper was then produced and presented at the North American Congress of Clinical Toxicology in October 2001 and at the EAPCCT Congress in May 2002 to allow participants to comment on the draft after which a revised draft was produced. The Position Paper was subjected to detailed peer review by an international group of clinical toxicologists chosen by the AACT and the EAPCCT, and a final draft was approved by the boards of the two societies. The Position Paper includes a summary statement (Position Statement) for ease of use, which will also be published separately, as well as the detailed scientific evidence on which the conclusions of the Position Paper are based. Urine alkalinization is a treatment regimen that increases poison elimination by the administration of intravenous sodium bicarbonate to produce urine with a pH > or = 7.5. The term urine alkalinization emphasizes that urine pH manipulation rather than a diuresis is the prime objective of treatment; the terms forced alkaline diuresis and alkaline diuresis should therefore be discontinued. Urine alkalinization increases the urine elimination of chlorpropamide, 2,4-dichlorophenoxyacetic acid, diflunisal, fluoride, mecoprop, methotrexate, phenobarbital, and salicylate. Based on volunteer and clinical studies, urine alkalinization should be considered as first line treatment for patients with moderately severe salicylate poisoning who do not meet the criteria for hemodialysis. Urine alkalinization cannot be recommended as first line treatment in cases of phenobarbital poisoning as multiple-dose activated charcoal is superior. Supportive care, including the infusion of dextrose, is invariably adequate in chlorpropamide poisoning. A substantial diuresis is required in addition to urine alkalinization in the chlorophenoxy herbicides, 2,4-dichlorophenoxyacetic acid, and mecoprop, if clinically important herbicide elimination is to be achieved. Volunteer studies strongly suggest that urine alkalinization increases fluoride elimination, but this is yet to be confirmed in clinical studies. Although urine alkalinization is employed clinically in methotrexate toxicity, currently there is only one study that supports its use. Urine alkalinization enhances diflunisal excretion, but this technique is unlikely to be of value in diflunisal poisoning. In conclusion, urine alkalinization should be considered first line treatment in patients with moderately severe salicylate poisoning who do not meet the criteria for hemodialysis. Urine alkalinization and high urine flow (approximately 600 mL/h) should also be considered in patients with severe 2,4-dichlorophenoxyacetic acid and mecoprop poisoning. Administration of bicarbonate to alkalinize the urine results in alkalemia (an increase in blood pH or reduction in its hydrogen ion concentration); pH values approaching 7.70 have been recorded. Hypokalemia is the most common complication but can be corrected by giving potassium supplements. Alkalotic tetany occurs occasionally, but hypocalcemia is rare. There is no evidence to suggest that relatively short-duration alkalemia (more than a few hours) poses a risk to life in normal individuals or in those with coronary and cerebral arterial disease.

Biopsy of the red patch at cystoscopy: is it worthwhile?

OBJECTIVE: At cystoscopy red patches of urothelium are commonly seen within the bladder and frequently biopsied in order to exclude carcinoma in situ (CIS), which classically presents as a red, velvety patch. This appearance however is not specific and it is possible that many lesions are biopsied without significant benefit to the patient. The objective of this study was to determine whether routine biopsy of red patches seen in the bladder at cystoscopy is warranted. PATIENTS AND METHODS: 193 biopsies were taken from red patches seen at flexible and rigid cystoscopy during a 4-year period from December 1997 to January 2002 and examined by histopathology. Patients included in the study were those on cystoscopic follow-up for transitional cell carcinoma (TCC) of the bladder and those undergoing investigation for haematuria or lower urinary tract symptoms. RESULTS: In 193 (17.7% of total biopsies) red patch biopsies, malignancy was found in 23 (11.9%) and 18 of 23 (78.3%) were CIS. No malignancies were detected in red patches from patients under the age of 60 years. CONCLUSION: Red patch biopsy yields a positive finding of malignancy in 12% and was concluded to be a valuable exercise, particularly in those over the age of 60 years and on follow-up for TCC.

Position paper: gastric lavage.

Gastric lavage should not be employed routinely, if ever, in the management of poisoned patients. In experimental studies, the amount of marker removed by gastric lavage was highly variable and diminished with time. The results of clinical outcome studies in overdose patients are weighed heavily on the side of showing a lack of beneficial effect. Serious risks of the procedure include hypoxia, dysrhythmias, laryngospasm, perforation of the GI tract or pharynx, fluid and electrolyte abnormalities, and aspiration pneumonitis. Contraindications include loss of protective airway reflexes (unless the patient is first intubated tracheally), ingestion of a strong acid or alkali, ingestion of a hydrocarbon with a high aspiration potential, or risk of GI hemorrhage due to an underlying medical or surgical condition. A review of the 1997 Gastric Lavage Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

Reliability of the MRCP(UK) Part I Examination, 1984-2001.

OBJECTIVES: To assess the reliability of the MRCP(UK) Part I Examination over the period 1984-2001, and to assess how the reliability is related to the difficulty of the examination (mean mark) and to the spread of the candidates' marks (standard deviation). METHODS: Retrospective analysis of the reliability (KR20) of the MRCP(UK) examination recorded in examination records for the 54 diets between 1984 and 2001. RESULTS: The reliability of the examination showed a mean value of 0.865 (SD 0.018, range 0.83-0.89). There were fluctuations in the reliability over time, and multiple regression showed that reliability was higher when the mean mark was relatively high, and when the standard deviation of the marks was high. CONCLUSIONS: The reliability of the MRCP(UK) Examination was maintained over the period 1984-2001. As theory predicted, the reliability was related to the average mark and to the spread of marks.

Magnetic resonance imaging-guided laser thermal ablation of renal tumours.

OBJECTIVE: To test the hypothesis that magnetic resonance imaging (MRI)-guided laser thermal ablation (LTA) of inoperable renal tumours is a safe, tolerable and potentially effective treatment. PATIENTS AND METHODS: Nine patients (aged 56-81 years) with malignant renal tumours underwent percutaneous LTA under MRI guidance in a 0.5 T open magnet. Real-time colour thermal mapping was used to monitor tumour ablation, and the follow-up was with gadolinium-enhanced MRI at 6 weeks and (where appropriate) 3-4 months after the procedure. Tumour volume and percentage tumour enhancement before and after ablation were compared. The percentage of tumour ablated on real-time T1-weighted thermal maps was compared with that on gadolinium-enhanced follow-up MRI. RESULTS: The mean (range) follow-up was 16.9 (3-32) months after the first ablation. The mean tumour size did not change significantly, but the mean percentage of viable tumour decreased significantly from 73.7% before to 29.5% after ablation (P = 0.012, Wilcoxon signed-ranks test). Thermal maps correlated moderately well with follow-up MRI in predicting the extent of tumour ablation (Pearson correlation coefficient 0.55). There were two minor and one major complication. CONCLUSION: In this pilot study of patients unsuitable for surgery, MRI-guided LTA of renal tumours was safe, feasible (being well tolerated by the patient) and significantly reduced enhancing tumour volume by a mean of 45%.