Eur Urol Suppl 2006;5(2):244 P54 UROGENITAL TRAUMA Friday, 7 April, 12.15-13.45, Room Concorde 3 / Level 4 885 DETECTION OF PROSTATE CANCER (PCA) BONE METASTASES USING MRI OF THE AXIAL-SKELETON (AS-MRI): EFFICIENCY AND COST-BENEFIT RATIO OVER TC-99M BONE SCAN Tombal B. 1 , Stainier A. 2 , Van Cangh P.J. 2 , Jamart F. 3 , Vande Bergh B. 4 , Lecouvet F. 4 1 Cliniques Universitaires Saint Luc, Urologie, Brussels, Belgium, 2 Cliniques Universitaires Saint Luc, Urology, Brussels, Belgium, 3 Cliniques Universitaires Saint Luc, Nuclear Medicine, Brussels, Belgium, 4 Cliniques Universitaires Saint Luc, Radiology, Brussels, Belgium INTRODUCTION & OBJECTIVES: Prostate cancer (PCa) is characterized by an exquisite tropism to bone. Although major breakdowns have been made in therapy, very little progresses have been made in the diagnostic of bone metastases, which still mostly rely on Tc-99m bone scans. Recently, we have developed and validated a MRI protocol to image the axial skeleton (AS-MRI) to measure bone metastases’ size and response to therapy. Here, we have prospectively evaluated the sensitivity, specificity and cost-effectiveness of AS-MRI to detect bone metastasis in high-risk PCa Patients. MATERIAL & METHODS: The study has prospectively enrolled 60 patients considered at high risk of bone metastases for a first diagnosis of PCa with a Gleason Score ≥ 8 and PSA ≥ 20 ng/ ml (n=20), a rapid PSA rise PSA after radical prostatectomy (PSAdt) <12 months; n=12), or rapid PSA rise under hormone therapy (PSAdt <12 months; n=18). All patients underwent Tc-99m bone scan and AS-MRI within a maximum interval of 4 weeks. All the Tc-99m positive (fixing) areas were considered for additional X-ray investigations. AS-MRI protocol and definition of pathological patterns (normal, focal, and diffuse) has been described previously. Costs for standard examinations were obtained from the Belgian healthcare service (INAMI). RESULTS: Tc-99 bone scan was negative in 10 (16.7%) patients and showed area of Tc-99m fixation in 50 patients (83,3%), all these later being further investigated by X-rays. These were normal in 11 (22%) patients, demonstrated metastases in 23 (46%) patients, and revealed degenerative benign lesions in 16 (32%). Overall, 23 (38%) patients were considered metastatic to bone. In contrast, AS- MRI was normal in only 22 (37%) patients, revealed metastases in 35 (58%) patients (23 focal lesions and with diffuse infiltration), and was inconclusive (focal lesions < 1cm) in 3 (5%) patients. A second AS-MRI was performed after 3 months in these 3 patients and demonstrated metastases in 2. AS-MRI thus finally increased the proportion of patients diagnosed with metastases by 20%. AS-MRI correctly identified metastases in all cases Tc-99m/X-Ray was considered positive (specificity: 100%). In contrast Tc-99m/X-Rays workup underestimated the presence of bone metastases in 14/37 patients (sensitivity 62%). Total cost, based on Belgian reimbursement policy, for 60 Tc-99m bone scan + X-rays of hot spots is € 12.528,17, while 60 AS-MRI cost € 15.200,40, representing a difference of € 44 per patients. In US, however, were reimbursement of AS-MRI is much higher, the additional cost/patients is > 500 $US. CONCLUSIONS: AS-MRI is a sensitive technique to detect bone metastasis. Overall, it increases the detection rate by 20%, in addition to allow precise measurement and monitoring of response to therapy. Its cost-effectiveness depends largely on local reimbursement policy. In Belgium, the cost overrun is marginal. 886 A COMPREHENSIVE RENAL INJURY CONCEPT BASED UPON IMPACT TESTS ON PORCINE KIDNEYS AND A VALIDATED (FRESH HUMAN CADAVER) FINITE ELEMENT MODEL OF THE HUMAN ABDOMEN Schmidlin F. 1 , Snedeker J. 2 , Niederer P. 2 , Farshad M. 3 , Iazzio P. 4 1 Clinic of Urology, Department of Surgery, Geneva, Switzerland, 2 Institute of biomedical Engineering, University of Zürich & ETHZ, Zurich, Switzerland, 3 EMPA, Zurich, Switzerland, 4 University of Minnesota, Department of Anaesthesiology, Minneapolis, United States INTRODUCTION & OBJECTIVES: Hidden kinematics interactions of the abdominal organs as well as their energy absorption during trauma are difficult to measure using standard biomechanical instrumentation. Computer models may predict injuries from complex soft tissue interactions thereby enabling the identification of injury mechanisms. Based upon these data clinical approaches may be refined and protective countermeasures be developed. The objective of this study was to develop a validated Finite Element Model of the human abdomen to investigate blunt renal trauma within an abdominal context. MATERIAL & METHODS: The right human kidney was modelled individually for the renal cortex, capsular membrane, calyces, veins and arteries. The isolated renal model was validated in dynamic impact tests using the porcine kidney model. The model was then embedded within a three dimensional Finite Element Model of the human abdomen created for use within the total human model for safety (THUMS). For the geometrical reconstruction anatomical data were taken from the Visible human project. The model was configured to simulate lateral, lower abdominal impact experiments on unembalmed human cadaver torsos. A 23.4 kg cylindrical impactor with a 150 mm diameter impactor face was directed laterally into the abdomen. An impact velocity of 4.7 m/s was simulated. RESULTS: Rupture of the renal capsule/parenchyma was considered to be the critical injury criteria. Strain energy density (SED>40kJ/m3) was identified to be a reliable predictor of tissue damage. Impact force is translated to the renal compartment through the ribcage. The 11 th and 12 th ribs were predicted to fracture, after which the rate of lateral abdominal compression accelerated. Approximately 20 ms after the initial impact, the kidney compartment underwent maximum compression. At about 10 ms, the renal body was deflected anteriorly by the psoas major and quadratus lumborum muscles, causing the kidney to eventually strike the anterior aspects of lumbar vertebrae L2 and L3. CONCLUSIONS: Simulation efforts using the detailed, three dimensional geometry of our abdominal FE model provide a much more realistic simulation of actual traumatic loading in lateral abdominal impact which clinically is most frequently associated with major injuries. We see that a likely renal injury mechanism in lateral impact is compression between the fractured ribcage wall and the anterior aspect of the lumbar vertebrae. The present FE Model of the abdomen may simulate interactions during lateral impact and calculate the strain energy density caused by specific impact energy. Based on these data we may now study ways to protect the kidney by decreasing the strain energy density below the acceptable threshold for a given impact. It may also be used to study common injury mechanisms between the liver and the kidney, thereby refining our understanding of associated injuries in the presence of major renal trauma. 887 RENAL TRAUMA: A 10-YEAR EXPERIENCE IN THE DIAGNOSIS AND TREATMENT OF RENAL INJURIES Lekas A. 1 , Fokitis I. 1 , Lefakis G. 1 , Charalampidis V. 1 , Tsalavoutas S. 2 , Koritsiadis S. 1 1 General Hospital of Nikea, Urology, Piraeus, Greece, 2 General Hospital of Nikea, Biochemical and Hormonal Laboratory, Piraeus, Greece INTRODUCTION & OBJECTIVES: Renal trauma occurs in about 1-5% cases of all injuries. The present study describes a ten-year experience of our department in the diagnosis and treatment of renal injuries. MATERIAL & METHODS: During the last 10 years, three hundred and eighty (380) patients suffering from renal injury of different grades of severity were treated in our department. Amongst them, three hundred and sixty eight (368) patients were injured during a car accident and twelve (12) patients were diagnosed with a penetrating injury. Three hundred and seventy eight (378) patients underwent clinical and laboratory tests and were also subject to image study by U/S and CT with IV contrast. The remaining two (2) patients were unstable at the time of presentation in the emergency room and the diagnosis was based on macroscopic hematuria and one-shot IVP during operation. RESULTS: One hundred and ninety five (195) patients were diagnosed with renal injury of Grade I-II (51.35%). In the above mentioned patients, the U/S image study conducted showed no evidence of renal trauma in ninety four (94) of them (48.2%) and the diagnosis was confirmed by the CT with IV contrast. The treatment period ranged from 1 to 3 days, whereas evidence of completeness of treatment was the normal urinary test and the normal levels of β2 microglobulin (in incidental urinary sample). Ninety five (95) patients were diagnosed with renal injury of Grade III (25%), sixty five (65) patients were diagnosed with renal injury of Grade IV (17.12%) and twenty five (25) patients were diagnosed with renal injury of Grade V (6.57%). All cases of renal injury of Grades I-III were treated conservatively. Nineteen (19) out of sixty five (65) patients suffering with renal injury of Grade IV (29.23%) received a pig-tail for monitoring and control of the urinoma. The remaining patients with renal injury of Grade IV and the patients with renal injury of Grade V were operated. CONCLUSIONS: Proper treatment of renal injury requires early diagnosis and identification of the grade of the trauma. β2microglobulin in urinary samples appears to be a marker of renal injury of high value and credibility, contributing to early diagnosis and reliable monitoring of patients. 888 FEATURES AND OUTCOMES OF PATIENTS WITH GRADE 4 RENAL INJURY Shariat S., Dhami G., Stage K. UT Southwestern, Urology, Dallas, United States INTRODUCTION & OBJECTIVES: The management of grade IV renal injuries remains controversial. We evaluated the features and outcomes of 75 consecutive patients with grade IV renal trauma. MATERIAL & METHODS: From 10/1995 through 10/2004, 424 consecutive patients presented to our hospital with traumatic renal injuries. RESULTS: 75/424 patients (18%) with renal trauma had grade IV injury. Median age was 29 years (range:12-80) and 80% were male. The mechanism of injury was blunt in 68% of patients and penetrating in 32% (25% gunshot and 9% stab wounds). 4% of patients had no hematuria, 24% had microscopic hematuria, and 72% had gross hematuria. 11% of patients presented with blood at the meatus. 69% of patients reported flank pain and 80% had abdominal pain. 14% of patients had flank ecchymosis. The initial mean systolic blood pressure, hematocrit, and creatinine were 118±34mmHg, 35±7%, and 1.2±0.6mg/dL, respectively. 22% of patient had systolic blood pressure below 90mmHg. 65% of patients required transfusion with the volume ranging from 0.5 to 32.8 liters (median: 2). The mean Glasgow Coma Scale and Revised Trauma Score were 13±3 and 11±2, respectively. Associated injuries were common (88%) with a 56% fracture rate. Renal exploration was performed in 78% of patients: 54% underwent renorrhaphy and 19% underwent nephrectomy. 94% of patients with penetrating trauma versus 55% with blunt trauma underwent renal exploration. 56% of patients underwent surgery for associated injuries (37% for abdominal injuries). CT diagnosed the degree of injury accurately in 100% of patients while “one-shot” intra-operative IVP was abnormal in 86% of patients. The number of hospital days ranged from 1 to 125 (median 9). All patients who stayed longer than 16 days had significant associated injuries. Overall 16% of patients died, all of whom had significant associated injuries. The overall and urologic complication rates were 44% and 22%, respectively. The urologic complication rate was lower in patients who underwent surgical exploration versus those who were observed (76% versus 83%). CONCLUSIONS: A significant proportion of patients with grade IV renal injury have microscopic or no hematuria. While approximately all patients with penetrating trauma require renal exploration, only approximately half of those with blunt trauma do. Pre-operative CT has a higher sensitivity than “one-shot” intra-operative IVP for accurate staging. The presence of other injuries is associated with worse outcome. Observation of grade IV renal injuries has a slightly higher urologic complication rate than renal exploration.