Objective To evaluate low-mechanical-index contrast-enhanced ultrasound (CEUS) in assessing the clinical efficacy and feasibility of percutaneous microwave ablation (MWA) for the treatment of renal cell carcinoma (RCC). Methods From March 2006 to July 2013, a total of 105 RCC patients with 109 lesions, mean size being (3.1 ± 1.3) cm, were treated with ultrasound-guided percutaneous MWA. CEUS results obtained on the third day after MWA were compared with the contrast-enhanced CT/MRI and biopsy findings in the corresponding period. Follow-up examinations with CEUS and CT/MRI were carried out 1, 3 and 6 months after the treatment and once every 6 months thereafter to evaluate the short-term and the long-term therapeutic effectiveness. Results Three days after MWA, CEUS showed that 94 of 109 lesions (86.2%) were completely ablated, and residual tumor tissue was seen in 15 of 109 lesions (13.8%). Among the 15 lesions with residual tumor tissue, 13 (86.7%) were proved by contrast-enhanced CT/MRI and/or biopsy performed in the corresponding period. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of CEUS for the evaluation of the short-term MWA effectiveness were 100%, 97.9%, 98.2%, 86.7% and 100%, respectively. Patients were followed up for 3 - 90 months with a median period of 24.6 months. During the follow - up period, CEUS detected recurrence in 7 patients, and 6 of them were consistent with CT/MRI results. The sensitivity, specificity, accuracy, positive and negative predictive value of CEUS for the evaluation of the long-term MWA effectiveness were 85.7%, 99.0%, 98.2%, 85.7% and 99.0%, respectively. Conclusion For the evaluation of the effectiveness of percutaneous microwave ablation in treating renal cell carcinoma, CEUS is a sensitive, reliable and convenient technique.

OBJECTIVETo investigate the value of real-time contrast-enhanced ultrasound (CEUS) in the diagnosis and differential diagnosis of renal solid renal lesions (RSLs).

METHODSWe retrospectively analyzed 140 cases of 152 RSLs with a mean diameter 3.1∓1.9 cm. CEUS was performed and the perfusion characteristics were analyzed using contrast pulse sequences (CPS) technique. CEUS findings were compared with biopsy histopathologic findings.

RESULTSA total of 137 malignant lesions (including 127 renal clear cell carcinomas, 8 renal papillary carcinomas and 2 chromophobe cell carcinomas) and 15 benign lesions (13 angiomyolipomas and 2 renal oncocytomas) were detected. Of the 137 malignant lesions, 98 (71.5%) showed contrast agent fast perfusion and hyper-enhancement or iso-enhancement in cortical phase, 104 (75.9%) showed hypo-enhancement in later corticalmedullary and late phase, and 125 (91.2%) showed rim-like enhancement. Tumors with a diameter ≤2 cm presented with homogeneous enhancement, and those ranging from 2 to 4 cm showed heterogeneous enhancement with a honeycomb feature; tumors greater than 4 cm featured heterogeneous enhancement with large no-enhancement necrotic areas. Of the benign lesions, 13 angiomyolipomas and 2 renal oncocytomas showed slow wash-in and slow wash-out mode. The diagnostic specificity, accuracy and positive predictive value of CEUS for RSLs were 94.9%, 96.1%, and 73.7%, as compared to 72.3%, 71.1%, and 19.1% with conventional US, respectively (P<0.001). The sensitivity and negative predictive value of CEUS were 93.3% and 99.2%, respectively, significantly higher than those of conventional US (60% and 94.3%, P=0.084, and 0.062, respectively).

CONCLUSIONReal-time CEUS can provide valuable information for improving the diagnosis and differential diagnosis of RSLs.

Adenoma, Oxyphilic ; diagnostic imaging ; Carcinoma, Renal Cell ; diagnostic imaging ; Contrast Media ; Diagnosis, Differential ; Humans ; Kidney Diseases ; diagnostic imaging ; Kidney Neoplasms ; diagnostic imaging ; Retrospective Studies ; Sensitivity and Specificity ; Ultrasonography

OBJECTIVETo investigate the feasibility, safety and efficacy of ultrasound-guided percutaneous microwave ablation (MWA) of splenic tumors.

METHODSSeven patients with 8 pathologically confirmed splenic tumors (including 2 metastases from the ovary and 4 from the lung, gastric adenocarcinoma, hepatocellular carcinoma, or rectal carcinoma; 1 hemangioma and 1 inflammatory pseudotumor) with sizes ranging from 1.3 to 6.2 cm (mean 3.1 ± 1.9 cm) were treated with MWA. A cooled shaft needle antenna was percutaneously inserted into the tumor under ultrasound guidance. A thermocouple was placed about 0.5 cm away from the tumor to monitor the temperature in real time during the ablation. The microwave emitting power was set at 50-60 W. The treatment efficacy was assessed by contrast-enhanced imaging at 1, 3 and 6 months following the procedure, and every 6 months thereafter.

RESULTSAll the tumors were completely ablated in a single session and no complications occurred. No local tumor progression was observed during a median follow up time of 13 months (4 to 92 months). The ablation zone, well defined on contrast-enhanced imaging, was gradually reduced with time. A new metastatic lesion was detected in the spleen at 11 months after the ablation in a ovarian carcinoma patient and was successfully treated by a second MWA. The post-ablation survival of the patients with splenic metastasis was 13 months (range 4 to 92 months). No complications other than fever and abdominal pain were observed in these patients.

CONCLUSIONUltrasound-guided percutaneous MWA is a safe and effective minimally-invasive technique for treatment of splenic tumors in selected patients.

Adenocarcinoma ; pathology ; Carcinoma, Hepatocellular ; pathology ; Catheter Ablation ; Contrast Media ; Female ; Humans ; Liver Neoplasms ; pathology ; Microwaves ; Minimally Invasive Surgical Procedures ; Ovarian Neoplasms ; pathology ; Splenic Neoplasms ; diagnostic imaging ; radiotherapy ; secondary ; Stomach Neoplasms ; pathology ; Treatment Outcome ; Ultrasonography