Comparison between high-frequency irreversible electroporation and irreversible electroporation ablation of small swine liver: follow-up of DCE-MRI and pathological observations.

BACKGROUND: High-frequency irreversible electroporation (H-FIRE) is a novel, next-generation nanoknife technology with the advantage of relieving irreversible electroporation (IRE)-induced muscle contractions. However, the difference between IRE and H-FIRE with distinct ablation parameters was not clearly defined. This study aimed to compare the efficacy of the two treatments in vivo. METHODS: Ten Bama miniature swine were divided into two group: five in the 1-day group and five in the 7-day group. The efficacy of IRE and H-FIRE ablation was compared by volume transfer constant (Krans), rate constant (Kep) and extravascular extracellular volume fraction (Ve) value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), size of the ablation zone, and histologic analysis. Each animal underwent the IRE and H-FIRE. Temperatures of the electrodes were measured during ablation. DCE-MRI images were obtained 1, 4, and 7 days after ablation in the 7-day group. All animals in the two groups were euthanized 1 day or 7 days after ablation, and subsequently, IRE and H-FIRE treated liver tissues were collected for histological examination. Student's t test or Mann-Whitney U test was applied for comparing any two groups. One-way analysis of variance (ANOVA) test and Welch's ANOVA test followed by Holm-Sidak's multiple comparisons test, one-way ANOVA with repeated measures followed by Bonferroni test, or Kruskal-Wallis H test followed by Dunn's multiple comparison test was used for multiple group comparisons and post hoc analyses. Pearson correlation coefficient test was conducted to analyze the relationship between two variables. RESULTS: Higher Ve was seen in IRE zone than in H-FIRE zone (0.14 ±â€Š0.02 vs. 0.08 ±â€Š0.05, t = 2.408, P = 0.043) on day 4, but no significant difference was seen in Ktrans or Kep between IRE and H-FIRE zones at all time points (all P > 0.05). For IRE zone, the greatest Ktrans was seen on day 7, which was significantly higher than that on day 1 (P = 0.033). The ablation zone size of H-FIRE was significantly larger than IRE 1 day (4.74 ±â€Š0.88 cm2vs. 3.20 ±â€Š0.77 cm2, t = 3.241, P = 0.009) and 4 days (2.22 ±â€Š0.83 cm2vs. 1.30 ±â€Š0.50 cm2, t = 2.343, P = 0.041) after treatment. Apoptotic index (0.05 ±â€Š0.02 vs. 0.73 ±â€Š0.06 vs. 0.68 ±â€Š0.07, F = 241.300, P < 0.001) and heat shock protein 70 (HSP70) (0.03 ±â€Š0.01 vs. 0.46 ±â€Š0.09 vs. and 0.42 ±â€Š0.07, F = 64.490, P < 0.001) were significantly different between the untreated, IRE and H-FIRE zones, but no significant difference was seen in apoptotic index or HSP70 between IRE and H-FIRE zone (both P > 0.05). Electrode temperature variations were not significantly different between the two zones (18.00 ±â€Š3.77°C vs. 16.20 ±â€Š7.45°C, t = 0.682, P = 0.504). The Ktrans value (r = 0.940, P = 0.017) and the Kep value (r = 0.895, P = 0.040) of the H-FIRE zone were positively correlated with the number of hepatocytes in the ablation zone. CONCLUSIONS: H-FIRE showed a comparable ablation effect to IRE. DCE-MRI has the potential to monitor the changes of H-FIRE ablation zone.

The treatment of non-small cell lung cancer by interstitial I-125 seeds implantation combined with chemotherapy and Chinese medicine.

OBJECTIVE: To investigate the effects of brachytherapy with computed tomography-guided percutaneous radioactive I-125 seeds interstitial implantation (ISI) synchronized chemotherapy and Chinese medicine (CM) for the treatment of advanced stage of non-small cell lung cancer (NSCLC). METHODS: Ninety patients diagnosed with NSCLC by biopsy were randomly assigned to three groups: the synchronized therapy group (A), the chemotherapy plus CM-treated group (B), and the chemotherapy-treated group (C); a 2-month course of treatment was administered to them all. The effectiveness of treatment was evaluated based on tumor size, tumor markers (carcinoembryonic, squamous cell carcinoma-associated antigen, and cytokeratin 19 fragment), clinical symptoms, and quality of life (QOL) in patients. RESULTS: The total effective rates of Groups A to C were 83.33%, 46.67%, and 43.33%, respectively. The tumor markers were reduced obviously in Group A, showing signifificant difference compared with those in the other two groups. Additionally, QOL was elevated and cancer-related symptoms were alleviated more signifificant in Group A than those in Group C (all P<0.05). CONCLUSION: The synchronized therapy of I-125 implantation with chemotherapy and CM was a safe therapeutic method and can be regarded as a new mode for treatment of advanced-stage NSCLC.

CT-guided conformal cryoablation for peripheral NSCLC: initial experience.

PURPOSE: To study the feasibility of CT-guided and monitored percutaneous conformal cryoablation of Non-Small Cell Lung Cancer for patients who are not suitable for surgical resection. MATERIALS AND METHOD: CT-guided percutaneous conformal cryoablation was performed on 46 patients with peripheral Non-Small Cell Lung Cancer. Patients with tumor sizes less than 3 cm in diameter were treated with double-needle clamping cryoablation, while the patients with 3-5 cm tumor sizes were treated with multiple-needle conformal cryoablation. CT was used to monitor the extent of cryoablation during the procedures. At month 1, 3, 6, 12, and 24 post-procedure, enhanced CT scans and/or PET-CT scans were performed to evaluate the impact of the therapy. RESULTS: The average tumor CT values were 32±10 HU and -21±8 HU before and after cryoablation, respectively. The largest diameters of the lesions at month 1, 3, 6, 12, and 24 post-procedure were 2.63±0.56 cm, 1.93±0.51 cm, 1.55±0.39 cm, 1.43±0.40 cm, and 1.38±0.38 cm, respectively, in patients with tumor diameter less than 3 cm, and 3.63±0.39 cm, 2.98±0.31 cm, 2.62±0.32 cm, 2.54±0.34 cm, and 2.56±0.37 cm respectively in patients with the tumor diameters between 3 and 5 cm. At the 24th month, there were 36 cases of complete response (83.7%), 7 cases of partial response (16.3%), and no cases of stable disease or progressive disease. 3 patients died due to multiple metastases. CONCLUSION: CT-guided percutaneous conformal cryoablation is a safe, effective, and minimally invasive therapeutic method for peripheral lung cancer.

CT-guided percutaneous cryoablation of osteoid osteoma in children: an initial study.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of CT-guided percutaneous cryoablation for osteoid osteoma in children. MATERIALS AND METHODS: This study was approved by the institutional ethics committee. From January 2007 to July 2008, six children (four boys, two girls, mean age 12.6 years old) with osteoid osteoma were treated with CT-guided percutaneous cryoablation. The procedures were carried out under conscious sedation and local anesthesia. CT guidance was used for procedural planning, instrument guidance, and monitoring. An argon-based cryoablation system was used. Each cryoablation included two freezing-thawing cycles. Follow-up was performed to assess technical and clinical outcome for a minimum of 12 months. A visual analog scale (VAS) was used to assess severity of pain pre- and post-procedure, and mean VAS for the group was compared pre- and post-procedure with a t-test. The mean clinical follow-up period was 28.7 months (ranging from 18 to 36 months). RESULTS: Cryoablation was technically and clinically successful for all patients. No major immediate or delayed complications were observed. Significant pain relief (P <0.05) was observed in all patients after operation. Mean VAS were 6.57 ± 0.55 pre-procedure and 0.57 ± 0.10 1 month post-procedure. Patients were allowed to fully bear their weight and function without limitation within 3 days after the procedure. Pain recurrence was not observed in any patient. CONCLUSION: Percutaneous cryoablation is safe and effective for the treatment of osteoid osteomas in children. Notably, this procedure can be accomplished without general anesthesia.

Magnetic resonance imaging-guided percutaneous cryoablation of hepatocellular carcinoma in special regions.

BACKGROUND: Local cryoablation guided by CT or ultrasound has been widely applied in the treatment of hepatocellular carcinoma. However, it is still difficult to apply this technique in certain regions such as the diaphragm dome, the first hepatic hilum, and regions adjacent to the gallbladder. This study aimed to evaluate the safety and efficacy of using magnetic resonance imaging (MRI)-guided percutaneous cryoablation as well as the effect of using an open MRI system in guiding and monitoring the treatment of hepatocellular carcinoma in these regions. METHODS: Cryoablation, guided by an open 0.35T MRI scanner and with the assistance of an MRI-compatible optical navigation system, was performed on 32 patients with hepatocellular carcinoma at the diaphragm dome, the first hepatic hilum, and regions adjacent to the gallbladder. Each patient had one or two tumors. The total number of tumors treated was 36. The tumor diameters ranged from 2.5 to 10.0 cm (mean 4.7+/-1.8 cm). The cryosurgical system was MRI-compatible and equipped with cryoprobes 1.47 mm in outside diameter. Under the guidance of MRI in combination with the optical navigation system, the cryoprobes were introduced percutaneously into a tumor at the planned targeting points while critical organs or tissues were avoided. Each cryoablation procedure included two freezing-thawing cycles, and MRI images were acquired dynamically to monitor the ablation of the tumor from time to time during the operation. In order to investigate the therapeutic effects of a cryoablation procedure, AFP measurements and liver-enhanced MRI or CT-enhanced scans were performed at regular times. RESULTS: MRI and optical navigation system-guided cryoablation procedures were successfully performed on all 32 patients (36 tumor sites) and no serious complications occurred. The follow-up period ranged from 5 to 12 months. The 6- and 12-month overall survival rates were 96.8% and 90.6%, respectively. According to the diagnosis of liver-enhanced MRI scans, 10 patients (31.3%) had complete ablation, 18 (56.3%) partial ablation (>80%), 3 (9.4%) stable disease (>50% ablation), and 1 (3.1%) progressive disease (a new tumor site in the liver). The overall efficacy was 87.5%. CONCLUSIONS: MR-guided percutaneous cryoablation using optical navigation is a safe and effective minimally invasive procedure for the treatment of hepatocellular carcinoma at certain special regions, which is difficult to treat with other imaging guidance approaches. With its unique and superb imaging functions, MRI plays an important role in the display, guidance, and monitoring of the cryoablation procedure in treating hepatocellular carcinoma at these special regions. Equipped with an MRI-compatible optical navigation system, MRI-guided therapy makes the cryoablation procedure more precise and safe.

CT-guided percutaneous chemical ablation of adrenal neoplasms.

OBJECTIVE: The objective of our study was to evaluate the feasibility and effectiveness of percutaneous chemical ablation of primary and metastatic adrenal neoplasms under CT guidance. MATERIALS AND METHODS: Thirty-seven patients with 46 adrenal tumors underwent CT-guided percutaneous chemical ablation. The average (+/- SD) tumor diameter was 4.2 +/- 2.0 cm. Acetic acid was injected in lesions with a diameter of more than 3 cm, and ethanol was injected in lesions with a diameter of less than 3 cm. Eleven adrenal lesions were nonfunctional adenomas, six lesions were corticosteroid adenomas (bilateral lesions in one patient), nine lesions were aldosteronomas (bilateral lesions in two patients), and 20 were metastases (bilateral metastases in six patients). RESULTS: Tumor volume decreased gradually during the first 2 years after the procedure. For primary tumors, a complete response (CR) rate of 92.3% (24/26) and a partial response (PR) rate of 7.7% (2/26) were obtained, but for metastasis, a CR rate of 30% (6/20) and PR rate of 70% (14/20) were obtained 24 months after therapy. The level of corticosteroid in five patients (six tumors) with Cushing's syndrome was in the normal range 3 months after the procedure. Seven patients (nine tumors) with Conn's syndrome began receiving oral antihypertensive medications during the first month after the procedure to maintain normal blood pressure and the dose was gradually decreased after 1 month. No severe complications were encountered. CONCLUSION: CT-guided percutaneous chemical ablation of adrenal tumors is an effective, minimally invasive, and easily performed procedure.

Nutcracker phenomenon: a new diagnostic method of multislice computed tomography angiography.

OBJECTIVE: We evaluated 3-D computed tomography angiography (3-D CTA) in the diagnosis of the nutcracker phenomenon, and its significance in postoperative follow up. PATIENTS AND METHODS: Three-dimensional CTA was used to compare the anatomical relations of the left renal vein with the aorta and the superior mesenteric artery in patients with the nutcracker phenomenon and in a control group. Four patients with the nutcracker phenomenon received a surgical procedure of the transposition of the left renal vein. The 3-D CTA was used for all patients during postoperation follow-up testing. RESULTS: The 3-D CTA showed a compression of the left renal vein between the aorta and the superior mesenteric artery (SMA) and the abnormal acute angle between them. The angles and distances between the SMA and the aorta were 39.3 +/- 4.3 degrees and 3.1 +/- 0.2 mm in the patient groups and 90 +/- 10 degrees and 12 +/- 1.8 mm in the control groups, respectively. Differences in angles and distances were statistically significant between the two groups (P < 0.05). Surgical transposition of the left renal vein was performed successfully. Postoperative 3-D CTA revealed the distance between the SMA and the aorta was nearly normal. CONCLUSION: The reconstruction imaging of the renal vein by means of 3-D CTA revealed that unusual hematuria was due to compression of the left renal vein; therefore it may be a useful alternative imaging technique instead of conventional examinations. The non-invasive 3-D CTA may be a useful tool in the diagnosis of the nutcracker phenomenon and follow-up testing.

[Clinical study of CT virtual endoscopy in staging diagnosis of bladder tumors].

OBJECTIVE: To evaluate CT virtual endoscopy (CTVE) based on spiral CT in the staging diagnosis of bladder neoplasms and its clinical application. METHODS: Forty patients with bladder neoplasms and 10 normal patients underwent volume scanning using spiral CT. All images with thin collimation and overlapping reconstruction were transferred to computer workstation to obtain the images of CTVE. The results of all CTVE findings were compared with those of conventional CT, cystoscopy, operation and pathological data. RESULTS: CTVE showed the normal anatomical structure of bladder as actual cystoscopy. The size, configuration, location and extension of bladder neoplasms was detected by CTVE scans agreed with that of actual cystoscopy. CTVE revealed the structure of trigone of urinary bladder that were not available in actual cystoscopy, and they were confirmed operatively and compared with the pathological results according to the TNM classification of malignant neoplasms. The sensitivity of CTVE for bladder tumors and accuracy in preoperative neoplasms staging was 98% (39/40) and 85% (33/39), respectively. The sensitivity of mass detection of diameter > or = 0.5 cm was 100%. The results were studied in a blind way. CONCLUSIONS: CTVE is a noninvasive, safe and reliable procedure in the staging diagnosis of bladder neoplasms. CTVE can well show bladder neck anatomy and serve as an important complementary method to conventional cystoscopy. The limitation of CTVE is that it can not observe change of mucosal appearances and perform biopsy.