Prognostic Significance of Advanced Age in Patients with T1a Renal Cell Carcinoma Treated by Microwave Ablation: A 16-Year Experience.

BACKGROUND: Previous studies have failed to investigate the specific effects of advanced age on survival outcomes by considering the Charlson Comorbidity Index (CCI) and age permutation in patients with T1a renal cell carcinoma (T1a RCC) treated by microwave ablation (MWA). Notably, RCC guidelines recommended radiofrequency ablation (RFA) and active surveillance (AS) are both treatment options for elderly T1a RCC, but whether MWA is superior to AS in light of higher heating efficiency and larger ablation zone compared with RFA is not clear. This study aimed to investigate the specific effects of advanced age on survival outcomes of T1a RCC patients stratified by CCI score and indicate better intervention for elderly T1a RCC between MWA and AS. METHODS: This was a retrospective study. We retrospectively reviewed 237 patients with T1a RCC who had undergone MWA over the last 16 years. Data were analyzed by Cox regression and Landmark analysis. Interaction tests and propensity score matching were used to account for potential biases. We compared the overall survival (OS) and cancer-specific survival (CSS) rates of patients ≥75 years in our study with corresponding figures from 4251 counterparts undergoing AS in published articles. RESULTS: Using patients ＜75 years with a CCI ≤2 as a reference, the hazard ratio (HR) and 95% confidence interval (CI) of OS for patients＜75 years with a CCI ≥3, patients ≥75 years with a CCI ≤2, and patients ≥75 years with CCI ≥3, were 2.954 (1.139-7.663), 3.48 (1.487-8.146), and 3.357 (1.162-9.698), respectively. The adverse effect of an age ≥75 years on OS was attenuated in patients with a CCI ≥3. The attenuation lasted for 62.5 months of follow-up (P = .017). Notably, advanced age exerted a protective effect on progression-free survival (PFS) in patients with a CCI ≥3, increasing the 8-year PFS from 67.8% to 100% (P = .049). Relative to 1-, 3-, 5-, and 8-year survival data for patients aged ≥75 undergoing AS, the OS rates for 5-year follow-up were always better in MWA. However, beyond 5 years, the OS rates dropped to levels that were similar to AS. CONCLUSIONS: Advanced age exerts adverse effects and significantly protective effects on OS and PFS, respectively, in T1a RCC patients with a CCI ≥ 3. According to our study, elderly patients with T1a RCC underwent radical MWA may yield a better medium-term OS relative to AS.

Colonic metastasis from hepatocellular carcinoma after treated by ablation and transarterial chemoembolization manifested by intestinal obstruction: A case report and review of the literature.

Hepatocellular carcinoma (HCC) with gastrointestinal tract metastasis is a rare condition. Recently, we encountered one case of HCC with direct invasion to the colon, which was manifested by intestinal obstruction. The patient was an 86-year-old man who underwent multiple transarterial chemoembolization and microwave ablation treatment for HCC lesions for 10 years. Two months after last palliative microwave ablation, computed tomography showed a 7.0-cm liver tumor directly invading the hepatic flexure of colon with the symptom of right abdominal pain and discontinuous nausea and vomiting. HCC colon metastasis with intestinal obstruction was diagnosed. Intestinal adhesion lysis and colostomy were performed. The patient survived 10 months after surgery and died of tumor progression.

Chemotherapeutic Nanoparticle-Based Liposomes Enhance the Efficiency of Mild Microwave Ablation in Hepatocellular Carcinoma Therapy.

Hepatocellular carcinoma (HCC) is the third leading cause of death from cancer, and the 5-year overall survival (OS) rate for HCC remains unsatisfying worldwide. Microwave ablation (MWA) is a minimally invasive therapy that has made progress in treating HCC. However, HCC recurrence remains problematic. Therefore, combination therapy may offer better outcomes and enhance MWA efficiency through improved tumor control. We have developed doxorubicin-loaded liposomes (DNPs) as an efficient nanoplatform to enhance MWA of hepatocellular carcinoma even at the mild ablation condition. In this study, we demonstrated that the uptake of DNPs by HCC cells was increased 1.5-fold compared with that of free DOX. Enhanced synergism was observed in the combination of DNPs and MWA, which induced nearly 80% cell death. The combination of mild MWA and DNPs enhanced the ablation efficiency of HCC with significant inhibition of liver tumors and accounted for the longest survival rate among all groups. A much higher accumulation of the DNPs was observed in the transitional zone than in the ablation zone. No apparent systemic toxicity was observed for any of the treatments after 14 days. The present work demonstrates that DNPs combined with MWA could be a promising nanoparticle-based therapeutic approach for the treatment of hepatocellular carcinoma and shows potential for future clinical applications.

Percutaneous Microwave Ablation versus Laparoscopic Partial Nephrectomy for cT1a Renal Cell Carcinoma: A Propensity-matched Cohort Study of 1955 Patients.

Background Percutaneous microwave ablation (MWA) and laparoscopic partial nephrectomy (LPN) are two modalities indicated for early-stage renal cell carcinoma (RCC) with low extent of invasion. Purpose To compare the long-term results of percutaneous MWA and LPN in the treatment of cT1a RCC. Materials and Methods This retrospective study included 1955 patients with cT1a RCC treated with percutaneous MWA or LPN between April 2006 and November 2017. Propensity score matching was used. Oncologic outcomes were analyzed by using the Fine-and-Gray competing risk models. Results A total of 185 patients underwent percutaneous MWA (mean age, 63.2 years ± 15.2 [standard deviation]) and 1770 underwent LPN (mean age, 50.9 years ± 13.2). During the follow-up (median, 40.6 months), after propensity score matching, no difference was observed between local tumor progression (3.2% vs 0.5%, P = .10), cancer-specific survival (2.2% vs 3.8%, P = .24), and distant metastases (4.3% vs 4.3%, P = .76). Patients who underwent percutaneous MWA had worse overall survival (hazard ratio, 2.4; 95% confidence interval: 1.0, 5.7; P = .049 vs LPN) and disease-free survival (82.9% vs 91.4%, P = .003). Percutaneous MWA led to smaller drop in estimated glomerular filtration rate at discharge (6.2% vs 16.4%, P < .001), smaller estimated blood loss (4.5 mL ± 1.3 vs 54.2 mL ± 69.2), lower cost ($3150 ± 2970 vs $6045 ± 1860 U.S. dollars), shorter operative time (0.5 minute ± 0.1 vs 1.8 minutes ± 0.6), and shorter postoperative hospitalization time (5.1 days ± 2.6 vs 6.9 days ± 2.8) (all P < .001 vs LPN). There were fewer cases of fever in the percutaneous MWA group (16.2% vs 73.0%, P < .001). Conclusion There were no significant differences regarding oncologic outcomes and complications between percutaneous microwave ablation and laparoscopic partial nephrectomy for patients with cT1a renal cell carcinoma. Percutaneous microwave ablation led to smaller renal function change and lower blood loss. For patients who cannot be subjected to the risks of more invasive laparoscopic partial nephrectomy, percutaneous microwave ablation could be an alternative less invasive treatment option. © RSNA, 2020 Online supplemental material is available for this article.

Theranostic liposomes as nanodelivered chemotherapeutics enhanced the microwave ablation of hepatocellular carcinoma.

Aim: This study aimed to develop indocyanine green- and doxorubicin-loaded liposomes (DILPs) as theranostic nanoplatform for the detection of hepatocellular carcinoma (HCC) and as an efficient chemotherapeutic to enhance microwave ablation. Materials & methods: DILPs were synthesized and thoroughly characterized. Biocompatibility, tumor uptake and accumulation, and synergistic ablation-chemotherapeutic efficiency were systematically explored in them. In addition, human HCC surgical samples were used to test the affinity of DILPs for HCC. Results: The combination of microwave ablation and DILPs enhanced the ablation efficiency of HCC with apparent tumor inhibition. DILPs exhibited excellent diagnostic ability and could detect 2.5-mm HCC lesions via optoacoustic tomography imaging. DILPs had better affinity for human HCC surgical samples compared with normal liver tissue. Conclusion: Theranostic DILPs could serve as promising nanoparticles for treatment and management of HCC in the clinic.

Ultrasound-guided percutaneous microwave ablation of central intraductal papilloma: a prospective pilot study.

Background: Central intraductal papilloma (IDP) has a low risk of cancer evolution; therefore, surgical treatment of IDP is controversial. We sought to validate ultrasound (US)-guided percutaneous microwave ablation (MWA) for minimally invasive treatment of IDP. Methods: Thirteen women with central IDP, including six with nipple discharge, underwent US-guided core needle biopsy and MWA from December 2016 to November 2017. Lesions histologically diagnosed as benign IDP were included. The hydro-dissection technique was used to protect the nipple during the entire ablation procedure. We evaluated and recorded data of complete ablation, volume reduction, and complications. Results: MWA was successfully performed in all patients, with 100% complete ablation, assessed by magnetic resonance imaging or contrast-enhanced US. Mean tumor size was 13.5 ± 4.1 (7.0-20.0) mm; the mean ablation time was 1.4 (0.7-10.3) min. At the median 13.7-month follow-up, mean lesion sizes at 3, 6, and 12 months after MWA were all significantly smaller than that at baseline. Total volume reduction rates were 52.3 ± 18.2% (range, 24.2-81.8%), 72.6 ± 23.1% (range, 39.4-95.9%), and 92.9 ± 7.5% (range, 75.0-100%) at 3-, 6-, and 12-month follow-up, respectively, with significant differences (p < .01). Three lesions with diameters 7 mm, 9 mm, and 12 mm disappeared completely at 3, 6, and 6 months after MWA, respectively, on US imaging. Nipple discharge disappeared immediately after MWA. Cosmetic effects were reported as excellent by all patients and no complications were observed. Conclusion: US-guided MWA of central IDP proved feasible and effective, with considerable volume reduction and satisfactory cosmetic outcomes.

Local tumor control of thoracoabdominal wall seeding tumor from hepatocellular carcinoma with ultrasound-guided interventional treatment: A summarized study.

OBJECTIVE: The aim of the study is to evaluate the effectiveness of ultrasound (US)-guided interventional treatments in local tumor control (LTC) for thoracoabdominal wall seeding tumor (TAWST) from hepatocellular carcinoma (HCC), and explore the survival outcomes of the patients underwent surgical resection (SR) and microwave ablation (MWA) for intrahepatic tumor. MATERIALS AND METHODS: A total of 40 patients with 47 TAWST from HCC were recruited from April 2007 to May 2018. LTC was evaluated by contrast-enchanced image. Long-time survival outcomes were compared. Overall survival (OS), disease-free survival (DFS), and local seeding progress-free survival (LSPFS) were analyzed. RESULTS: One-year LTC rate was 65.2% in all patients; 72%, 0%, 50%, and 0% in the patients who underwent MWA, high-intensity focused US, iodine-125 (125I) brachytherapy and MWA combined with 125I brachytherapy, respectively. The 3-year OS, DFS rates and LSPFS rates were 51.8% and 28.6%, 12.0% and 23.8%, and 10.0% and 10.0% after MWA and SR, respectively. Univariate analysis results showed that age (P = 0.049), Karnofsky performance scale (KPS) (P = 0.002), and chemoradiation (P = 0.032); and multivariate analysis results showed that age (P = 0.045) and KPS (P = 0.010) might be predictors for LCT. While univariate analysis results showed that KPS (P = 0.032), intrahepatic tumor size (P = 0.006), chemoradiation (P = 0.003), preoperative alpha-fetoprotein level (P = 0.007), metastasis (P = 0.049), and albumin-bilirubin grade (P = 0.002), and multivariate analysis results showed that comorbidities (P = 0.004), KPS (P = 0.007), and metastasis (P = 0.009) might be predictors for OS. The pain degree of patients was improved obviously after treatments. CONCLUSIONS: US-guided interventional treatments were an effective option in LTC for TAWST from HCC, and MWA could achieve comparable long-time survival outcomes with SR for HCC patients with TAWST.

Correction: Liposomes loading sodium chloride as effective thermo-seeds for microwave ablation of hepatocellular carcinoma.

Correction for 'Liposomes loading sodium chloride as effective thermo-seeds for microwave ablation of hepatocellular carcinoma' by Jie Yu, Ping Liang et al., Nanoscale, 2017, 9, 11068-11076.

Local tumor progression after ultrasound-guided percutaneous microwave ablation of stage T1a renal cell carcinoma: risk factors analysis of 171 tumors.

PURPOSE: To retrospectively review long-term oncologic outcomes after ultrasound (US)-guided percutaneous microwave ablation (MWA) of T1a renal cell carcinoma (RCC) and to identify the incidence and risk factors that predict local tumor progression (LTP) after MWA of RCC. MATERIALS AND METHODS: The present study was approved by the institutional review board. A total of 162 patients with 171 RCC nodules (mean size, 2.6 ± 0.8 cm; range, 0.6-4.0 cm) were treated by MWA between April 2006 and January 2017. The influence of eight factors (age; sex; longest tumor diameter; tumor number, location and pathology type; ablation power and time) affecting the risk of LTP was assessed. Univariate Kaplan-Meier and Cox proportional hazard models were used for statistical analysis. RESULTS: LTP occurred in five patients (5 tumors) after US-guided percutaneous MWA of stage T1a RCC. The overall occurrence of LTP was 2.9% per tumor and 3.0% per patient with a median follow-up of 45.5 months. Among the 162 patients, there were no instances of LTP-related deaths; however, 20 patients died of other diseases. All patients with LTP survived through follow-up. The survival rate of LTP-free patients at 1, 3 and 5 years were 98.7%, 89.5% and 82.1%, respectively (p = .38). Univariate and multivariate analysis identified tumor location to be the only independent predictor of LTP. CONCLUSIONS: US-guided percutaneous MWA for T1a RCC achieved a relatively low LTP incidence rate. Tumors adjacent to the renal pelvis or bowel increased the potential of LTP occurrence.

Ultrasound guided percutaneous microwave ablation of benign breast lesions.

The benign breast lesions (BBLs) share a high incidence for women and therapy methods with minimal invasion and better cosmetic outcome are thirsted for. In this study, 122 patients with 198 biopsy-proved BBLs were enrolled. Ultrasound (US)-guided microwave ablation (MWA) was performed with local anesthesia from November, 2013 to April, 2016. The mean longest tumor size assessed was 1.6±0.7 cm (ranging 0.7-4.9 cm). MWA was successfully performed in all cases including 85 lesions adjacent to the skin, pectoralis and areola. The mean ablation time was 3.2mins (ranging 0.5-18.3 mins). 99.5% of BBLs showed complete ablation when assessed by magnetic resonance imaging and 100% of them by US. At the median 14-month follow-up, the BBLs were not palpable in 45.9 % of the cases (palpable in 90.2 % of the cases before MWA) and the mean volume reduction ratio was 78.4±33.5% for total lesions and 89.3±20.8%, 84.7±27.6% and 55.9±32.9% for ≤1.0 cm, 1.1-2.0cm and >2.0 cm lesions in 12-month follow-up, respectively. Cosmesis were reported as good or excellent in 100 % by physician and patients. No side effect was found. The MWA of the BBLs proved feasible and effective, while showing meaningful reduction in volume, palpability and cosmetic satisfying outcomes.

Liposomes loading sodium chloride as effective thermo-seeds for microwave ablation of hepatocellular carcinoma.

Microwave ablation (MWA) is a promising minimally invasive therapy that has been widely used to treat hepatocellular carcinoma (HCC). However, the efficiency of MWA in treating HCC is evidently limited by the incomplete ablation of large tumors and tumors in high-risk locations. Here, we report the value of using liposomes packed with sodium chloride (NaCl-LPs) as effective thermo-seeds for MWA of HCC. The prepared liposomes exhibited excellent heat conversion ability by showing a more rapid temperature increase than free NaCl medium, blank liposomes or water under microwave irradiation. The high efficiency of this new microwave sensitization strategy was fully demonstrated in vitro in subcutaneous and orthotopic tumors. The results showed that MWA combined with NaCl-LPs clearly enhanced the ablation efficiency, leading to apparent tumor inhibition and low recurrence. What's more, we verified the susceptibility of NaCl-LPs on orthotopic tumors. Based on the unique properties of NaCl-LPs, sublethal MWA was used to mimic the transitional zone, and large-scale necrosis was observed in tumors combined with NaCl-LPs. In addition, HE staining and blood hematology analysis revealed no noticeable toxicity of NaCl-LPs in vivo, which confirmed that NaCl-LPs possessed good biocompatibility. CONCLUSION: The effective nanoparticles could play a valuable role in enhancing the thermo-sensitizing effect of MWA for achieving better therapeutic efficacy.

[Long-term effects of ultrasound-guided microwave ablation in the treatment of small renal cell carcinoma].

OBJECTIVE: To evaluate the long-term efficacy of microwave ablation in the treatment of small renal cell carcinoma (RCC). METHODS: We retrospectively analyzed 140 cases of small cell renal carcinoma (151 lesions with a mean diameter of 2.8±0.8 cm) treated between April, 2006 and October, 2015 with ultrasound-guided microwave ablation with cooled-shaft needle antenna. One microwave ablation antenna was used for tumors less than 2 cm in diameter and 2 antennas were used for larger tumors. The patients received enhanced ultrasound and CT/MRI examinations at 1, 3, and 6 months after the operation and every 6 months thereafter. The overall survival, disease-free survival, and local tumor progression rate of the patients were evaluated. RESULTS: The response rate of treatment (complete ablation at one month on enhanced images) was 100% in these patients. The local tumor progression rates at 1, 3, and 5 years were 0.9%, 2.0%, and 7.1%, respectively, and the 1-, 3-, and 5-year distant metastasis rates were 1.6%, 2.5%, and 7.9%, respectively. The overall survival rates of the patients at 1, 3, and 5 years were 98.4%, 94.8%, 89.5%, respectively, with disease-free survival rates of 98.4%, 93.0%, and 83.1%, respectively. No major complications occurred in these cases, and multivariate analysis showed that the tumor number (P=0.015) and tumor growth patterns (P=0.049) were independent risk factors that adversely affected the long-term outcome after surgery. CONCLUSION: Our data show that microwave ablation is a safe and effective modality for treatment of renal cell carcinoma.

Midterm results of percutaneous microwave ablation under ultrasound guidance versus retroperitoneal laparoscopic radial nephrectomy for small renal cell carcinoma.

Laparoscopic radial nephrectomy (LRN) and microwave ablation (MWA) are optional treatment for renal cell carcinoma (RCC). However, the comparative study with two techniques remains lacking. The aim of this study was to evaluate midterm results of MWA vs. LRN in patients with small RCC. A total of 426 patients with ≤ 4 cm RCC were included from April 2006 to October 2012. Ninety-eight patients underwent MWA and 328 patients LRN. The survival, recurrence, and renal function changes were compared between two treatments. Although overall survival after MWA (82.6% at 5 years) was lower than those after LRN (98.6% at 5 years, p = 0.0004), the RCC-related survival (97% at 5 years) was comparable to those following LRN (98% at 5 years, p = 0.38). One local tumor progress occurred at 32 months after MWA and none after LRN. The major complication rates were comparable between two techniques (1.7% in MWA vs. 1.5% in LRN, p = 0.75), but MWA showed less renal function damage than LRN (p < 0.0001). The multivariate analysis showed the presence of postablation extrarenal metastasis may become a predictor of the oncologic outcome (p = 0.059) and treatment modality had no influence (p = 0.965). This study demonstrates that MWA and LRN provide comparable results in small RCC outcomes.

[Clinical evaluation of ultrasound-guided percutaneous microwave ablation of splenic tumors].

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

Local tumour progression after ultrasound-guided microwave ablation of liver malignancies: risk factors analysis of 2529 tumours.

OBJECTIVES: To identify the incidence and risk factors that predict local tumour progression (LTP) after ultrasound-guided percutaneous microwave ablation (MWA) of liver malignancies. MATERIALS AND METHODS: One thousand two hundred and nine patients with 2,529 malignant nodules (mean size 2.8 ± 1.4 cm, range 0.9-8.0 cm) were treated by MWA between July 2005 and December 2012. The influence of 11 factors on the risk of LTP was assessed. Univariate Kaplan-Meier and Cox proportional hazard models were used for statistical analysis. RESULTS: The overall LTP was 4.2 % per tumour and 8.6 % per patient with a median follow-up of 20.3 months. LTP per tumour was 4.3 % for primary liver cancer and 4.1 % for metastases (p = 0.32). The survival of LTP and free-LTP patients at 1, 3, and 5 years was 92.4 %, 71.6 %, and 45.1 %, respectively, and 92.9 %, 70.1 %, and 52.4 %, respectively (p = 0.93). By univariate analysis, tumour location, size and ablation time were significant risk factors of LTP. Multivariate analysis identified tumour size (>3.0 cm) to be the only independent predictor of LTP. CONCLUSIONS: MWA of liver malignancies achieves a relatively low-incidence LTP, although LTP risk significantly increases if tumour size >3.0 cm. The technique seems to be appropriate even for patients with a tumour at a risk location. KEY POINTS: • Microwave ablation of liver malignancies achieves a low incidence local tumour progression. • LTP risk significantly increases if the tumour size is >3.0 cm. • MWA seems to be appropriate even for patients with a tumour at a risk location.

[Value of real-time contrast-enhanced ultrasound in diagnosis of renal solid renal lesions].

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

US-guided percutaneous microwave ablation versus open radical nephrectomy for small renal cell carcinoma: intermediate-term results.

PURPOSE: To review intermediate-term clinical outcomes of microwave ablation (MWA) compared with open radial nephrectomy (ORN) in small renal cell carcinoma (RCC) patients and to identify prognostic factors associated with two techniques. MATERIALS AND METHODS: This retrospective study was institutional review board-approved. A total of 163 patients (127 men and 36 women) with small RCC (≤4 cm) were included from April 2006 to March 2012. Sixty-five patients underwent MWA and 98 patients underwent ORN. Survival, recurrence, and renal function changes were compared between the two groups. Effect of changes in key parameters (ie, overall survival, RCC-related survival, and metastasis-free survival) was statistically analyzed with the log-rank test. RESULTS: Although overall survival after MWA was lower than that after ORN (P = .002), RCC-related survival was comparable to ORN (P = .78). Estimated 5-year overall survival rates were 67.3% after MWA and 97.8% after ORN; for RCC-related survival, estimated 5-year rates were 97.1% after MWA and 97.8% after ORN. There was one local tumor recurrence 32 months after MWA and none after ORN. Major complication rates were comparable (P = .81) between the two techniques (MWA, 2.5% vs ORN, 3.1%). The MWA group had less surgical time (P < .001), estimated blood loss (P < .001), and postoperative hospitalization (P < .001). Multivariate analysis showed age (P = .014), tumor type (P = .003), postoperative urea nitrogen (P = .042), comorbid disease (P = .005), and treatment modality (P < .001) may become survival rate predictors. CONCLUSION: In intermediate term, ultrasonographically guided percutaneous MWA and ORN provide comparable results in oncologic outcomes. MWA appears to be a safe and effective technique for management of small RCC in patients with little loss of renal function.

The assistant function of three-dimensional information for I125 particle implantation.

The purpose of this study was to explore the assistant function of 3-D information for I125 particle implantation of multineedle intervention under the guidance of ultrasound. The assistant function of 3-D information was verified by a simulation experiment system which consists of an ultrasound probe, an abdominal phantom, the preoperative computed tomography image of a patient, the electromagnetic tracking device, and the self-developed 3-D image navigation software with a practical and friendly graphical user interface. The simulation particle implantation experiments were divided into the two groups. The first group of experiments was performed with the aid of 3-D information. Seven days later, the second group of experiments was carried out with the aid of 2-D information. We made the statistical analysis of the experimental results obtained by nine medical students, nine interventional radiologists, and nine attending physicians. With the assistance of 3-D information, the percentage of tumor coverage increased (p < 0.01), the operation time shortened (p < 0.01), and the number of insertions reduced (p < 0.01). The assistant function of 3-D information for particle implantation of multineedle intervention under the guidance of ultrasound was technically feasible and effective.

US-guided percutaneous microwave ablation of renal cell carcinoma: intermediate-term results.

PURPOSE: To retrospectively review intermediate-term (median, 20.1 months) clinical outcomes after microwave ablation (MWA) of renal cell carcinoma (RCC). MATERIALS AND METHODS: This retrospective study was approved by the institutional review board. The results from 46 patients with 49 RCC nodules (diameter, 0.6-7.7 cm; mean, 3.0 cm ± 1.5 [standard deviation]) treated with ultrasonography (US)-guided percutaneous MWA with cooled-shaft needle antenna from April 2006 to December 2010 were reviewed. One antenna was used for tumors smaller than 2 cm; two, for tumors 2 cm or larger. The patients were followed up with contrast material-enhanced US and computed tomography or magnetic resonance imaging at 1, 3, and 6 months and every 6 months thereafter. The effect of changes in key parameters (including overall survival, disease-free survival, and local tumor progression rate) was statistically analyzed by using the log-rank test. RESULTS: Technical effectiveness (complete ablation at follow-up enhanced imaging 1 month after MWA) was achieved in 48 of 49 (98.0%) tumors, and the metastasis-free rate was 100% (46 of 46). The 1-, 2-, and 3-year local tumor progression rates were 4.6%, 7.7%, and 7.7%, respectively. The cancer-specific survival rate was 100% (46 of 46), and 1-, 2-, and 3-year overall survival rates were 100%, 100%, and 97.8%, respectively. The 1-, 2-, and 3-year disease-free survival rates were 95.4%, 92.3%, and 92.3%, respectively. No major complications occurred. Multivariate analysis showed that tumor number (P = .046), tumor growth patterns (P = .003), and ablation time (P = .04) were independent unfavorable prognostic factors. CONCLUSION: In the intermediate term, US-guided percutaneous MWA appears to be a safe and effective technique for the management of RCC, especially small RCC, in selected patients.