Feasibility of Computed Tomography-guided Percutaneous Renal Cryoablation Under Local Anesthesia: A Single Center Experience in Taiwan.

BACKGROUND/AIM: To survey the safety and efficacy of percutaneous cryoablation for renal tumors under local anesthesia and pain control by using the -40°C lethal isotherm of the ice ball to cover the tumor margin as well as the coaxial cryoablation technique. PATIENTS AND METHODS: All procedures were performed between February 2014 and November 2021 with computed tomography (CT) guidance. All tumors were ablated by following the aforementioned plan, according to which tumor margins were covered by the -40°C lethal isotherm. Hydrodissection and coaxial cryoablation were performed in some cases to avoid organ injury and massive bleeding. 2% xylocaine was used for local anesthesia and 50 mg of pethidine (meperidine) was injected intramuscularly for pain control and sedation. The complications were evaluated and the Kaplan-Meier method was used to estimate local recurrence-free survival (LRFS). RESULTS: Sixty-five tumors [49 renal cell carcinomas (RCC) and 16 angiomyolipomas] were ablated in 55 patients (median Charlson Comorbidity Index=5.0). Local recurrence occurred in three of the 49 RCC cases. Two received a second cryoablation. LRFS at three and five years were both 91%. LRFS at three and five years reached 100% in tumors <3 cm. A large tumor (≥3 cm) was observed in the recurrence group. Hemorrhage was the most common complication (76.9%). Two patients who needed blood transfusion did not receive coaxial cryoablation. Three (4.6%) major complications (Clavien-Dindo grade ≥3) occurred. CONCLUSION: By using -40°C as the pre-plan tumor coverage, with the aid of coaxial cryoablation and multiplanar reconstruction method, CT-guided percutaneous renal cryoablation under local anesthesia is a safe and effective procedure in patients with many comorbidities.

Assessment of Prostate Volume and Prostate-specific Antigen Density With the Segmentation Method on Magnetic Resonance Imaging.

BACKGROUND/AIM: This study aimed to compare the prostate volume (PV) and prostate-specific antigen density (PSAD) obtained using the ellipsoid volume formula or segmentation methods on magnetic resonance imaging (MRI) and further predict prostate cancer (PCa). PATIENTS AND METHODS: Retrospectively, the enrolled patients underwent prostate MRI and had PSA levels between 4 and 10 ng/ml. The PV was measured with both the ellipsoid volume formula (PVe) and the segmentation method (PVs). The transitional zone volume (TZV) was measured with the segmentation method. The PSADe, PSADs, and PSAD_TZV were calculated. Bland-Altman plots were used to compare the agreements. ROC curve analysis was used to compare the diagnostic accuracies to predict PCa. The results were also compared between the PCa and the no-PCa groups, and among tumors with different locations and different Gleason scores (GS). RESULTS: Seventy-six of the 117 enrolled patients were classified into the PCa group. There were high agreements between PVs and PVe as well as between PSADs and PSADe, while several outliers were mainly due to post-transurethral resection of the prostate changes and irregular hyperplastic nodules. The diagnostic accuracy of PSADe (AUC: 0.732) was slightly higher than that of PSADs (AUC: 0.729) and PSAD_TZV (AUC: 0.715). The PSADe and PSADs were not different among different tumor locations but were higher in GS ≥7 lesions (both p=0.006). CONCLUSION: The segmentation method can be an alternative method to measure PV and calculate PSAD before prostate biopsy, particularly in post-transurethral resection of the prostate patients or those with irregular hyperplastic nodules.

Assessment with magnetic resonance imaging and spectroscopy in Lhermitte-Duclos disease.

Lhermitte-Duclos disease (LDD) is a rare benign lesion of uncertain pathogenesis characterized by distortion of the normal cerebellar laminar cytoarchitecture. We report a 22-year-old man admitted for injury sustained in a traffic accident with the incidental finding of a cerebellar mass. Magnetic resonance imaging (MRI) revealed a mass lesion within the right cerebellar hemisphere. The final diagnosis of LDD was made by obtaining a surgical specimen and identifying the characteristic appearance of the lesion by MRI study. The images showed the typical striated pattern of hyperintensity on T2-weighted images and corresponding hypointensity on T1-weighted images, as well as the typical absence of enhancement following gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) administration. In addition, no disturbance of water diffusion on diffusion-weighted MRI, and associations of decreases in the N-acetylaspartate/creatine (NAA/Cr) and NAA/Choline (Cho) ratios with near normal values of Cho/Cr, as well as an obvious lactate peak gave supplemental information for diagnosis.