Objective To evaluate the feasibility and clinical efficacy of retroperitoneal laparoscopic partial nephrectomy (RLPN) with individual operation plan in treatment of small renal cell carcinoma (RCC). Methods 98 patients with small RCC who was treated by RLPN from June 2012 to June 2016 were retrospectively analyzed. There were 57 males and 41 females with a mean age of 52 years old (ranging 28 ~ 75 years old). 52 cases were located on the right side while 46 cases were left. The mean tumor size was 3.1 cm in diameter (ranging 0.8 ~ 4.5 cm). 87 patients (A group) were underwent standard RLPN with clamping main renal artery. 7 patients (B group) with exophytic RCC were performed without clamping renal artery, but with separating main renal artery and prepared for possible clamping. 4 patients (C group) with endophytic RCC were performed with clamping renal artery under ultrosound monitoring. The feasibility and outcomes were evaluated by surgical and oncological outcomes. Results 84 cases among A group were underwent standard RLPN successfully, with 2 cases converted to open surgery and 1 case failed to excising tumor completely and converted to laparoscopic radical nephrectomy. The amount of bleeding during operation was 30 ~ 350 ml, average 93 ml, operation time was 70 ~ 245 min, average 127 min, warm ischemia time 20 ~ 42 min, average 26 min. 6 cases among B group were performed successfully without clamping renal artery with 1 case converted to clamp renal artery for 15 min during the operation because of obvious bleeding. The amount of bleeding was 160 ~ 380 ml, average 220 ml, operation time was 85 ~ 215 min, average143 min. 4 cases of C group were all performed successfully, The amount of bleeding was 35 ~ 250 ml, average 85 ml, operation time was 110 ~ 235 min, average 175 min, warm ischemia time 25 ~ 40 min, average 28 min. With a mean follow up of 28 months (ranging 18 ~ 42 months), there was only 1 case of A group occured local recurrence and lung metastases and accepted molecular targeted therapy with Sorafenib. Conclusion RLPN with individual operation plan in treatment of small RCC is safe and effective, the long-term effect of the procedure needs further investigation.

Objective To investigate the value and diagnostic efficiency of the quantitative dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) and intravoxel incoherent motion (IVIM) parameters using three dimention (3D)-histogram analysis for discriminating the Gleason score (GS) of prostate cancer. Methods A total of 53 patients pathologically confirmed as prostate cancer by systemic prostate biopsy who had routine , DCE and DWI-MRI scans were retrospectively analyzed. There were 15 cases for low-risk and 38 cases for intermediate/high-risk prostate cancer. The 3D ROI of all lesions based on T2WI was achieved by image registration to get the quantitative parameters of DCE-MRI and DWI-IVIM. The parameters of DCE-MRI contains: transfer constant (Ktrans), rate constant (Kep) and extracellular-extravascular volume fraction (Ve).The DWI-IVIM related quantitative parameters were ADC, diffusion coefficient (D), diffusion coefficient related to perfusion (D*) and perfusion fraction (f). Then the histogram analysis of these quantitative parameters was performed to get the mean, median, 25th percentile, 75th percentile, Skewness and Kurtosis. Using the Spearman rank correlation analysis to evaluate the correlation of these parameters and GS of prostate cancer. The diagnostic performance of these quantitative histogram parameters related to the GS in identifying low-risk and intermediate/high-risk of prostate cancer was carried by ROC. Results The Kep and Ktrans (mean, median, 25th, 75th) of DCE-MRI were positively correlated with GS (r value was 0.346 to 0.696, P<0.05). The ADC (mean, median, 25th, 75th), D (mean, median, 25th, 75th, Skewness, Kurtosis) and D*(25th) of DWI-IVIM were correlated with GS (r value was-0.544 to 0.428, P<0.05). The DCE-MRI quantitative parameters Kep (25th) had the highest area under curve (AUC, 0.961); The ADC (median) and D (25th) had higher AUC( 0.832, 0.888) in the quantitative parameters of DWI-IVIM, the difference between Kep(25th) and ADC (median) was statistically significant (Z value was 2.212, P value was 0.027). The difference of AUC between Kep (25th) and D (25th), D (25th) and ADC (median) was not statistically significant (Z values were 1.027 and 1.398, P values were 0.162 and 0.304, respectively).Conclusion DCE and IVIM quantitative parameters (Kep, Ktrans, ADC, D) histogram analysis results are correlated with GS, and can be used for distinguishing low-risk from intermediate/high-risk prostate cancer.