CRYOABLATION OF PROSTATE CANCER USING 17-GAUGE CRYONEEDLES TECHNOLOGY 4-YEAR EUROPEAN EXPERIENCE

CRYOABLATION OF PROSTATE CANCER USING 17-GAUGE CRYONEEDLES TECHNOLOGY 4-YEAR EUROPEAN EXPERIENCE

445 446 PROSTATE CRYOSURGERY: NOT ALL THE FREEZING PROBES ARE THE SAME CRYOABLATION OF PROSTATE CANCER USING 17-GAUGE CRYONEEDLES TECHNOLOGY 4-YEAR...

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PROSTATE CRYOSURGERY: NOT ALL THE FREEZING PROBES ARE THE SAME

CRYOABLATION OF PROSTATE CANCER USING 17-GAUGE CRYONEEDLES TECHNOLOGY 4-YEAR EUROPEAN EXPERIENCE

Ahmed S., Davies J.

Witzsch U., Dillenburg W., Poulakis V., Becht E.

The Royal Surrey County Hospital, Urology, Guildford, United Kingdom

Krankenhaus Nordwest, Urology and Pediatric Urology, Frankfurt, Germany

INTRODUCTION & OBJECTIVES: Cryosurgery has become an effective minimally invasive treatment option for localised prostate cancer. The technique of the procedure varies amongst urologists. Moreover, there is more than one cryosurgery system available for prostate cancer: The CryocareTMsystem utilizes 2.4 or 3.4 mm in diameter freezing probesand the SeednetTMsystem which uses 1.47mm in diameter needles. Experiments have shown that not all the ice is effective to eradicate cancer cells, only temperatures of ≤ -40°C is considered to be lethal. Therefore, thermal information of the iceball is important to ensure adequate freeze and avoid collateral damages. Although the most reliable method to measure iceball temperature is by thermosensors, the technique is prone to considerable error during the procedure. The aim of our study is to map and compare the thermal distributions and the cooling rates of the iceballs of the three cryoprobes in vitro.

INTRODUCTION & OBJECTIVES: Prostate gland cryoablation for organ-confined disease has evolved dramatically during the last two decades, with significant reductions in complication rates and with improved outcomes. Improvements in transrectal ultrasound (TRUS) technology and the introduction of the 17 gauge cryoneedles (Oncura, USA) have made it possible for an urologist to monitor and precisely control ice formation during the procedure. We show our experience of the last 4 years.

MATERIAL & METHODS: Using special templates, 2 or 8 freezing probes were placed into a cube of bovine muscle (kept at 30-38°C) in a configuration similar to clinical scenario. Thermal distribution of each of the three probes’ iceball was assessed by measuring the temperatures of several horizontal levels 5 mm apart using up to 15 thermosensors. Each experiment was repeated three times for verification. We measured and compared the maximum dimensions of the iceball and the lethal zone, the non-lethal zone thickness, the cooling rate and the ablative ratio (percentage of the lethal / total ice volume) of each iceball. We assessed the effect of changing the cooling rate from 100% to 20% on all these parameters. RESULTS: The 2.4mm probe had the highest ablative ratio and the thinnest non-lethal ice thickness compared to the other iceballs. The more invasive 3.4mm probes produced the largest iceball, but mainly from non-lethal ice. The iceball of the 1.47mm probes had the widest kill zone, but significantly the shortest lethal zone height. The 0 - 5 minute mean cooling rates were 18.5, 20.6, 19.7 degree/min for the 2.4, 3.4 and 1.47mm probes respectively. Reducing the cooling rate to 20% resulted in a significant reduction in the kill zone dimensions, cooling rate and the ablative ratio for all the iceballs. CONCLUSIONS: The 2.4mm probe produced satisfactory iceball, having the thinnest non-lethal thickness and the highest ablative ratio. The more invasive 3.4mm probe has little advantages, and potentially associated with higher risks of complications. There is no evidence that the differences in the cooling rates are clinically significant. The most remarkable feature of the 1.47mm iceball is being significantly short, therefore, we advocate performing a “pull back” technique in freezing the prostate unless when the urethral length is short (< 22mm). We recommend using the highest cooling rate if possible particularly when using the 1.47 mm probes. These are in vitro experiments and yet to be translated into clinical settings.

KIDNEY TUMOURS: LAPAROSCOPIC TREATMENT Thursday, 6 April, 14.00-15.30, Room Blue / Level 2 447 MORBIDITY AND CLINICAL OUTCOME OF NEPHRON-SPARING SURGERY IN RELATION TO TUMOUR SIZE AND INDICATION

MATERIAL & METHODS: Between September 2001 and October 2005, 105 prostate cryoablation procedures were performed in Krankenhaus Nordwest, Frankfurt, Germany. Most patients (pts.) were referred from other centres. Pts. were classified as “favourable” if they had PSA <10ng/ml, Gleason <7, Tumour stage < T3, 24% of the pts. were patients with favourable characteristics. Pts. were classified as “unfavourable” if they did not met all three of the stated parameters. In this series 53% of the patients were primary or salvage patients with unfavourable characteristics. However they were not radiation salvage patients. A further 23% were failures after radiotherapy and were not classified as either favourable or unfavourable. From 9 to 19 17-gauge, cryoneedles were percutaneously placed in the prostate under transrectal ultrasound guidance. Two cryoneedles and a thermo sensor were placed in the area between the rectal wall and Denonvillier’s fascia for temperature monitoring and active thawing. During the freezing process rectal temperature was closely monitored and when a reading of below 15° C was noted, rectal warming was activated simultaneously. A “pull back” (of 15 mm median) was done for prostates longer than 35 mm (62%). RESULTS: PSA

<0,1ng/ml

0,1-0,5 ng/ml

>0,5 ng/ml

3 months

45%

19%

36%

12 months

42%

10%

48%

24 months

48%

17%

35%

36 months

25%

50%

25%

Histology was available in 40% of pts. The biopsy or TUR-P showed no residual cancer in 77% of the patients. Four patients are on antihormonal treatment due to rising PSA, but without signs of local recurrence. A further more 4 pts. were re-treated with cryotherapy because of local recurrence. Two pts. died due to secondary malignancies and four because of cardiopulmonary problems during their course years after the cryotherapy. One patient died due to PCa. CONCLUSIONS: Although most of the pts. were at high risk for progression, the results are encouraging. Third generation cryoablation of the prostate is a minimally invasive alternative for pts. who are contraindicated for radical prostatectomy due to high risk of advanced disease or comorbidity.

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Patard J.J.1, Crepel M.1, Pantuck A.J.2, Lam J.S.2, Bellec L.3, Soulie M.3, Albouy B.4, Pfister C.4, Lopes D.5, Salomon L.5, De La Taille A.5, Abbou C.C.5, Bernhard J.C.6, Ferriere J.M.6, Lacroix B.7, Tostain J.7, Colombel M.8, Martin X.8, Lobel B.1, Guille F.1, Figlin R.A.2, Belldegrun A.S.2 1

Rennes University Hospital, Urology, Rennes, France, 2Ucla, Urology, Los Angeles, United States, 3Toulouse University Hospital, Urology, Toulouse, France, 4Rouen University Hospital, Urology, Rouen, France, 5Creteil University Hospital, Urology, Creteil, France, 6Bordeaux University Hospital, Urology, Bordeaux, France, 7St Etienne University Hospital, Urology, St Etienne, France, 8Lyon University Hospital, Urology, Lyons, France INTRODUCTION & OBJECTIVES: To analyse through a large multicentre series the morbidity of NSS in relation to tumour size and indication. MATERIAL & METHODS: The study included patients from 8 international academic centres. Age, gender, TNM stage, tumour size, Fuhrman grade, Eastern Cooperative Oncology Group performance status (ECOG-PS), overall and cancer specific survival were noted. The specific data that was collected for the purpose of this study included: indication for NSS (elective vs. mandatory), medical and surgical complication rates, mean blood loos, blood transfusion and the length of hospital stay. Information regarding surgical margins, local and distant recurrence rates was also noted. Qualitative and quantitative variables were compared by using Chi-square (Fischer exact test) and Student t tests, respectively. RESULTS: A total of 1048 NSS procedures performed at 8 academic institutions were included in this study. Mean tumour size was 3.4±2.1 cm. Tumours were smaller than 4 cm in 801 cases (76.1%). NSS procedure was performed for a mandatory indication in 318 cases (30.3%) including 145 solitary kidneys (13.8%). Overall, medical and surgical complications occurred in 131 (12.5%) and 133 (12.7%) cases, respectively. Urinary fistula was noted in 32 cases (3.1%). Blood transfusion rate was 15.3% and median blood loss was 200 ml (0-4000). In 730 elective procedures: mean operative time (p:0.002), mean blood loss (p:0.01), collecting systems repair, blood transfusion (p:0.001) and urinary fistula rates (p:0.01) were significantly increased in tumours larger than 4 cm. However this did not result in significantly increased medical (p:0.4) or surgical complication rates (p:0.6) or in increased length of hospital stay (0.9). Finally, in elective procedures: positive surgical margins, local or distant recurrence rates, and cancer specific survival were not significantly different in tumours smaller and larger than 4 cm. CONCLUSIONS: Excellent cancer control and outcomes can be achieved with NSS in carefully selected patients with tumours greater than 4 cm. Expanding the size indications of NSS results in an increased but acceptable morbidity. However it is important to counsel patients regarding these additional risks when deciding on a radical vs. partial approach, especially in elderly patients or in those with significant co-morbidities.

Eur Urol Suppl 2006;5(2):134

448 A COST ANALYSIS OF LAPAROSCOPIC VERSUS OPEN RADICAL NEPHRECTOMY IN THE MANAGEMENT OF SOLID RENAL TUMOURSTHE EXPERIENCE OF A TERTIARY UK REFERRAL CENTRE Kommu S.S.1, Siddiqui E.2, Patel S.2, Wright M.P.2, Mumtaz F.H.3, Persad R.A.2 1

St. Anthony’s Hospital, Urology, Surrey, United Kingdom, 2The Bristol Urological Institute, Urology, Bristol, United Kingdom, 3Barnet and Chase Farm Hospitals NHS Trust, Urology, London, United Kingdom INTRODUCTION & OBJECTIVES: In the last decade, the national number of radical nephrectomies per year in the United Kingdom (UK) has increased by 20% and this was accompanied by an increase in annual hospital volume of about two-fifths. During the same period, laparoscopic radical nephrectomy (LRN) for renal cell carcinoma has also become established as a safe and effective alternative to open surgery. However, in the current cost conscious health care system, the main drawback to this shift has been the high perceived costs of laparoscopy, which had a major impact on the theatre budget of hospitals. Thus, the aim of this study was to compare the overall cost patterns of LRN with that of Open radical nephrectomy (ORN) in the management of solid renal tumours in a U.K. tertiary oncological referral setting. MATERIAL & METHODS: The records of 43 patients treated surgically for renal tumours from January 2001 to September 2005 were analysed. A costings tally was performed for all cases using a computer-generated template (CGT) of detailed cost variables. Specific to our CGT was an elimination criterion where cases were excluded if there was a non-matched consumable (e.g. if surgical drain was not used in a given case, that patient would be excluded). Thirty-five patients fit the criterion for analysis in this study; 15 had LRP and 20 had ORP. To adjust for temporal changes in costings over the 4-year period, we used projected costings for the year 2005 based on variables in the CGT. RESULTS: The mean costs for LRN were (£2,827.33 GBP United Kingdom Pounds i.e. € 4,177.32) compared with ORN (£3,566.17 GBP i.e. € 5,270.18). ORN was greater in cost than LRN by a factor of 1.26 (P<0.01). There were no significant differences in operative times. The mean post operative stay for LRN vs. ORN was 3.2 days (76.8 hrs) and 5.7 days (136.8 hrs) respectively (P=0.001) i.e. ORN resulted in a post operative stay of 1.8 times greater than LRN. CONCLUSIONS: In our study, the overall cost of ORN is greater than LRN by a factor of 1.3 if postoperative stay is included. From a strictly health economic point of view, LRN is more cost effective than ORN. In addition to the current established advantages of the laparoscopic approach including less blood loss, fewer hospital days, fewer complications, and more rapid recovery than open surgery, we found that cost is also in favour of LRN. We conclude that LRN should be offered as the first line treatment of solid renal malignancies in those cases where surgical extirpation is indicated.