Clinical evaluation of ultrasound-guided percutaneous microwave ablation of splenic tumors / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the feasibility, safety and efficacy of ultrasound-guided percutaneous microwave ablation (MWA) of splenic tumors.</p><p><b>METHODS</b>Seven 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.</p><p><b>RESULTS</b>All 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.</p><p><b>CONCLUSION</b>Ultrasound-guided percutaneous MWA is a safe and effective minimally-invasive technique for treatment of splenic tumors in selected patients.</p>

Percutaneous microwave ablation for renal cell carcinoma：evaluation of therapeutic effect with contrast-enhanced ultrasound / 介入放射学杂志

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.

Value of real-time contrast-enhanced ultrasound in diagnosis of renal solid renal lesions / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the value of real-time contrast-enhanced ultrasound (CEUS) in the diagnosis and differential diagnosis of renal solid renal lesions (RSLs).</p><p><b>METHODS</b>We 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.</p><p><b>RESULTS</b>A 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).</p><p><b>CONCLUSION</b>Real-time CEUS can provide valuable information for improving the diagnosis and differential diagnosis of RSLs.</p>