Efficacy Of Microwave Ablation Research Articles

Microwave ablation of lung malignancies with coexisting severe emphysema: a retrospective analysis of safety and efficacy in 26 patients

Purpose This retrospective study aimed to evaluate the safety and efficacy of microwave ablation (MWA) for lung malignancies in patients with severe emphysema. Materials and methods The clinical records of 1075 consecutive patients treated for malignant lung tumors in our department were retrospectively reviewed. Emphysema was assessed based on standard-dose computed tomography (CT) and was considered severe when it occupied ≥25% of the lung. Overall, 26 patients (24 men and 2 women; mean age ± standard deviation [SD]: 71.23 ± 8.18 years, range: 59–88 years) with severe emphysema underwent CT–guided percutaneous MWA for treating 26 tumors (24: non-small cell lung cancer and 2: metastases). The mean tumor size was 3.0 cm (SD: 1.5, range: 1.2–6.5 cm). Follow-up was performed with CT at 1, 3, 6, 12 months after ablation, and every 6 months thereafter. Complications and efficacy were evaluated. Results The median follow-up duration in all patients was 17.5 months (range: 5–37 months, interquartile range: 15.8). The mortality rate was 0% within 30 days after ablation. Major complications including pneumonia, lung abscess and refractory pneumothorax occurred in 19.2% (5/26) patients. The technical success and efficacy rates were 88.5% (23/26) and 87.0% (20/23), respectively, and the local tumor progression rate was 30.0% (6/20). Conclusion MWA appears to be a safe and effective therapeutic option for treating lung malignancies in patients with severe emphysema.

Microwave ablation eustachian tuboplasty: a preliminary investigation with long-term follow-up

ObjectivesThis study was performed to evaluate the efficacy of microwave ablation (MWA) eustachian tuboplasty for the treatment of patients with retracted tympanic membrane (TM) due to eustachian tube dysfunction (ETD).MethodsThis was a prospective study of 20 patients with ETD (middle ear atelectasis) who underwent MWA eustachian tuboplasty. Outcomes included the ability to perform a Valsalva maneuver, audiometry results, tympanometry results, ETD Questionnaire (ETDQ-7) score, and TM status.ResultsEighteen patients (18 ears) were included in this study. There were statistically and clinically significant improvements in the mean ETDQ-7 score at 6 months postoperatively (change in mean score of 16.7 ± 3.6, P < 0.001) and at 30 months postoperatively (change in mean score of 18.9 ± 2.9, P < 0.001).Type A tympanogram was obtained in 27.8% of patients (5/18) at 6 months postoperatively, and in 77.7% at 30 months postoperatively. A Valsalva maneuver was possible in 72.2% of patients at 6 months postoperatively and in 88.9% of patients at 30 months postoperatively. In addition, the ears of 13 patients (72.2%) showed both normal tympanograms and TM at 30 months postoperatively. Interestingly, 38.5% of patients (5/13) exhibited complete sclerosis of the pars tensa. None of the patients experienced severe MWA-related complications during follow-up.ConclusionsMWA eustachian tuboplasty is a feasible alternative to conventional tuboplasty, and can improve subjective and objective outcomes in patients with ETD for up to 30 months following treatment. In addition, this study showed that the extent of sclerotic plaque increased over time, whereas the extents of atrophy and tensa retraction decreased following tuboplasty in most patients.Graphical abstract

Standardizing percutaneous Microwave Ablation in the treatment of Lung Tumors: a prospective multicenter trial (MALT study).

To prospectively assess reproducibility, safety, and efficacy of microwave ablation (MWA) in the treatment of unresectable primary and secondary pulmonary tumors. Patients with unresectable primary and metastatic lung tumors up to 4 cm were enrolled in a multicenter prospective clinical trial and underwent CT-guided MWA. Treatments were delivered using pre-defined MW power and duration settings, based on target tumor size and histology classifications. Patients were followed for up to 24 months. Treatment safety, efficacy, and reproducibility were assessed. Ablation volumes were measured at CT scan and compared with ablation volumes obtained on ex vivo bovine liver using equal treatment settings. From September 2015 to September 2017, 69 MWAs were performed in 54 patients, achieving technical success in all cases and treatment completion without deviations from the standardized protocol in 61 procedures (88.4%). Immediate post-MWA CT scans showed ablation dimensions smaller by about 25% than in the ex vivo model; however, a remarkable volumetric increase (40%) of the treated area was observed at 1 month post-ablation. No treatment-related deaths nor complications were recorded. Treatments of equal power and duration yielded fairly reproducible ablation dimensions at 48-h post-MWA scans. In comparison with the ex vivo liver model, in vivo ablation sizes were systematically smaller, by about 25%. Overall LPR was 24.7%, with an average TLP of 8.1 months. OS rates at 12 and 24 months were 98.0% and 71.3%, respectively. Percutaneous CT-guided MWA is a reproducible, safe, and effective treatment for malignant lung tumors up to 4 cm in size. • Percutaneous MWA treatment of primary and secondary lung tumors is a repeatable, safe, and effective therapeutic option. • It provides a fairly reproducible performance on both the long and short axis of the ablation zone. • When using pre-defined treatment duration and power settings according to tumor histology and size, LPR does not increase with increasing tumor size (up to 4 cm) for both primary and metastatic tumors.

Comparison of microwave ablation treatments in patients with renal secondary and primary hyperparathyroidism

Purpose Microwave ablation (MWA) is feasible for severe renal secondary hyperparathyroidism (SHPT) and primary hyperparathyroidism (PHPT) patients ineligible for parathyroidectomy (PTX). Here we compared the clinical manifestations and characteristics of parathyroid glands in these two groups, and summarized the techniques, safety and efficacy of MWA. Methods Baseline clinical characteristics, ablation-related techniques, adverse events/complications, and efficacy were recorded. Results In SHPT group, malnutrition, cardiovascular/pulmonary complications, and abnormal bone metabolism were severe. SHPT patients had more hyperplastic parathyroid glands. The volume of each gland was smaller, and the time of ablation for a single parathyroid was shorter in the SHPT group, although there were no significant differences compared with patients in the PHPT group. Three patients in both groups had recurrent laryngeal nerve injuries and all recovered, except for one SHPT patient. By the end of follow-up, serum iPTH levels had decreased from 2400.26 ± 844.26 pg/mL to 429.39 ± 407.93 pg/mL (p < .01) in SHPT and from 297.73 ± 295.32 pg/mL to 72.22 ± 36.51 pg/mL in PHPT group (p < .01). Hypocalcemia was more common (p < .001) and serum iPTH levels were prone to rebound in SHPT patients after MWA. Conclusion MWA can be reserved for those who had high surgical risks because of less invasiveness. Injuries of recurrent laryngeal nerves should be noticed. The health status, perioperative, and intraoperative procedures were more complicated and all parathyroids found by ultrasound should be ablated completely in SHPT patients.

Microwave ablation or plus monochemotherapy in elderly advanced non-small-cell lung cancer patients

Objective To evaluate the efficacy of microwave ablation (MWA) and MWA plus monochemotherapy in elderly patients with advanced non-small-cell lung cancer (NSCLC). Material and methods Patients with advanced NSCLC aged ≥70 years were retrospectively enrolled. MWA was performed at the primary tumor site. The end points included progression-free survival (PFS), response to MWA and overall survival (OS). Results Fifty-four patients were enrolled; of these, 36 received monochemotherapy. Complete ablation was achieved in 42 patients (77.8%). The median PFS and OS were 4.9 months and 21.8 months, respectively. Univariate analyses showed that female patients had superior PFS (31.9 months [95% confidence interval (CI): 0.8–63.0]) vs. 5.0 months in male patients (95% CI: 2.0–8.0), p = .002). Female sex was associated with better OS (not reached vs. 10.8 months, 95% CI: 9.3–12.3, p = .003). Moreover, patients with primary tumor size <3.5 cm had better OS than those with tumor size ≥3.5 cm (not reached vs. 10.9 months, 95% CI: 8.2–13.6, p = .006). Multivariate analyses showed that no characteristics were independent prognostic factors of PFS, but sex and primary tumor size were independent prognostic factors of OS. Conclusion MWA was effective in the treatment of elderly patients with advanced NSCLC.

SAT-278 COMPARISONS OF MICROWAVE ABLATION TREATMENT IN PATIENTS WITH SECONDARY AND PRIMARY HYPERPARATHYROIDISM

Parathyroidectomy (PTX) is the first choice of treatment for patients with severe uremic secondary hyperparathyroidism (SHPT) and primary hyperparathyroidism (PHPT). However, patients with serious cardiac and/or pulmonary comorbidities are at increased risks of complications of general anesthesia. To alleviate clinical symptoms, microwave ablation (MWA) of hyperplastic parathyroid glands may be feasible for patients who are not eligible for PTX. The aim was to compare the key points of techniques and evaluate the safety and efficacy of MWA in SHPT and PHPT patients.

US-guided microwave ablation for primary hyperparathyroidism: a safety and efficacy study.

To evaluate the safety and efficacy of microwave ablation (MWA) with the assistance of continuous cool saline injection (CCSI) in patients with primary hyperparathyroidism (PHPT). Between November 1, 2014, and February 29, 2016, 22 patients with PHPT were enrolled and treated with ultrasound-guided MWA assisted by CCSI. The levels of parathyroid hormone (PTH) and serum calcium were recorded before and after the MWA. Patients were divided into two groups (normalized and unnormalized groups) according to treatment efficacy. Fisher's exact test and the Mann-Whitney test were used to compare data between the two groups. Timing differences in serum PTH and calcium levels were analyzed with repeated measures analysis of variance. Normalized outcomes for both PTH and calcium levels were achieved in 19 of 22 (86.36%) patients with PHPT. In the normalized group, PTH levels remained normal for 12months after MWA. PTH levels in the unnormalized group were outside the reference range at six of seven follow-ups within 12months following MWA. By contrast, serum calcium levels gradually decreased in all patients in both groups. The mean serum PTH and mean calcium levels at 6months after therapy were significantly lower than those before MWA (both p < 0.05). A transient voice change developed in eight patients. One patient experienced hypocalcaemia, which was corrected by oral calcium supplementation within 2months. US-guided MWA assisted by CCSI is safe and effective for destroying parathyroid gland tissue and may serve as a therapeutic alternative for patients with PHPT. • Microwave ablation is a new option for patients with hypercalcemic or normocalcemic primary hyperparathyroidism. • Microwave ablation can decrease PTH and calcium levels with sustained efficacy in most patients. • Treatment is safe and causes only transient side effects.

03:54 PM Abstract No. 89 Safety and efficacy of microwave ablation in the setting of treatment for stage T1b renal cell carcinoma

03:54 PM Abstract No. 89 Safety and efficacy of microwave ablation in the setting of treatment for stage T1b renal cell carcinoma

Preliminary report of microwave ablation for the primary papillary thyroid microcarcinoma: a large-cohort of 185 patients feasibility study.

To assess the safety and efficacy of microwave ablation (MWA) for primary papillary thyroid microcarcinoma (PTMC) with a large sample of 185 patients. A total of 185 patients underwent MWA for 206 primary PTMC nodules. They received ultrasound follow-up at 1, 3, 6, and 12 months after MWA and every 6 months thereafter. Nodule volumes were calculated at each follow-up and compared with those before MWA. Additionally, the volume reduction rate (VRR) of the nodules was calculated. Patients' thyroid functions were tested before and 1 month after MWA. The mean follow-up time of the 185 patients was 20.7 ± 8.8 months (range 12-36 months). During the follow-up period, the mean volume of the 206 nodules was 100.1 ± 92.9 mm3 (range 3.6-423.9) before MWA, which decreased to 2.2 ± 5.6 mm3 (range 0-20.3 mm3) after MWA (P = 0.000). The mean VRR of the nodules was 98.65 ± 3.60% after MWA (range 83.85-100%). One hundred and seventy four of 206 nodules (84.5%) were fully absorbed. Compared with the preoperative results, no significant variation in thyroid function was observed 1 month after MWA. Thirty-eight patients (20.5%) had different types of complications, ranging from minor to major. Five patients (2.7%) had hoarseness, 11 patients (5.9%) had bleeding, 21 patients (11.4%) had earache or toothache, and one patient had another lesion 1 month after MWA. This preliminary study suggests that MWA is safe and effective in the treatment of primary PTMC and offers a new alternative for clinical treatment.

Identification of bleeding sites and microwave thermal ablation of posterior epistaxis

Background: Microwave ablation (MWA) is a relatively new technique which has been used to achieve hemostasis at surgical field. However, few publications have reported MWA for epistaxis.Objectives: Our objectives were to identify the bleeding sites/points in instances of posterior epistaxis and to evaluate the efficacy of MWA for controlling bleeding.Material and methods: Patients with posterior epistaxis who met the inclusion criteria were examined and treated endoscopically using MWA. Recurrent bleeding and complications were evaluated at 1 and 3 months after treatment.Results: Of the 71 patients, the bleeding site/point was identified in 67 patients while 4 patients was unknown. Of the 67 patients with known bleeding sites, the olfactory cleft was in 44 patients, the middle meatus in 5 patients, and the inferior meatus in 18 patients. Only the bleeding point was coagulated in the 67 patients while prophylactic MWA in the 4 patients. No side effects or complications (including recurrent bleeding, crusting, nasal discomfort, and nasal septal perforation) were seen at 3-month follow-up.Conclusions: MWA may effectively control posterior epistaxis with a low cost and without complications.

Feasibility and safety of ultrasound-guided percutaneous microwave ablation for tertiary hyperparathyroidism

Background: Tertiary hyperparathyroidism (THPT) is very common in hemodialysis patients with secondary hyperparathyroidism. However, a medical treatment is not indicated for THPT.Purpose: To investigate the feasibility, safety and efficacy of microwave ablation (MWA) in treating THPT.Materials and methods: Twenty-three patients with THPT were enrolled and treated with MWA. Clinical characteristics, serum levels of intact parathyroid hormone (iPTH), calcium, phosphorus and alkaline phosphatase (ALP), as well as treatment outcomes, were evaluated pre- and post-MWA. All patients were followed for >36 months for all assessable clinical data.Results: All patients successfully completed MWA. The mean follow-up was 47.0 ± 8.4 months. Immediately 1-day post-MWA, iPTH, calcium, phosphorus and ALP levels significantly decreased (all p < 0.001). During the long-term follow-up, iPTH levels increased gradually until 24 months and then remained at stable levels. After MWA, serum calcium reached stable levels at 24 months, while phosphorus and ALP reached stable levels at 6 months, and the levels were in the normal range or slightly higher than the upper normal limit. No obvious blood flow signals or significant recurrence was observed in the surgical nodules during follow-up. In the last follow-up, all nodules were persistent, but their maximum diameter and average volume were significantly lower after MWA (both p < 0.001), with an average reduction of 75.9 ± 11.3%. All patients had no major complications during MWA and follow-up.Conclusions: MWA is feasible, safe, effective and minimally invasive in treating THPT. Thus, MWA can be a nonsurgical alternative for treating THPT patients who are ineligible for surgery.

Laparoscopic Assisted Percutaneous Microwave Ablation for Hepatocellular Carcinoma Close to Large Hepatic Vessels

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. It was believed that ablation for tumors close to large vessels should be avoided for the concern of major complications. Microwave ablation (MWA) seemed to be a better choice than radiofrequency ablation (RFA) in treating HCC close to large vessels (≥ 3 mm), for its advantages of a lower susceptibility to heat-sink effects (blood-vessel-mediated cooling), as well as the ability to achieve larger tumor volumes in shorter time. The aim of this study is to evaluate safety and efficacy of MWA for HCC close to large vessels. Methods: 32 patients with 52 HCC lesions were included, all patients have a lesion close to large vessel. 14 patients had single lesion, 16 had two lesions and 2 had three lesions. All patients are Child-Pugh A or B within Milan Criteria and class A disease Barcelona Clinic Liver Cancer (BCLC). Results: This study was conducted on 32 HCC patients 24 males and 8 females with median age 63 years. 32 HCC lesions were close to large vessel while 20 lesions were not close to large vessel. Laparoscopic assisted percutaneous MWA was decided as the treatment of choice for all patients. two patients (6%) had major complications (one patient had right portal vein thrombosis and the other patient had intra-hepatic hematoma), 3 patients (9%) had minor complications in the form of skin burn. Local tumor progression (LTP) occurred in 2 lesions (3.8% of lesions). Conclusion: laparoscopic assisted percutaneous MWA proved to be a safe and effective as a management for HCC close to large vessels.

Microwave ablation combined with transcatheter arterial chemoembolization is effective for treating unresectable hepatoblastoma in infants and children

The present study is to evaluate the feasibility and efficacy of microwave ablation (MWA) combined with transcatheter arterial chemoembolization (TACE) in the treatment for unresectable hepatoblastoma in infants and children. A total of 17 patients with PRETEXT stage III and IV hepatoblastoma that was unresectable by conventional resection were included in the present study. The patients were treated with TACE, MWA, and chemotherapy. All cases were diagnosed by computed tomography (CT) and liver tumor biopsy before TACE procedure. All patients received 2 courses of TACE and 1 to 2 times of MWA. Finally, several cycles of chemotherapy were arranged. Among the 17 patients, 14 were alive and had normal alpha-fetoprotein (AFP) levels. The other 3 patients died from tumor progression. The follow-up periods ranged from 10 to 68 months. Complete ablation was achieved in the 14 patients (14/17, 82.35%). Most patients were well tolerated during the whole course except for 1 patient with pneumonedema after TACE and another 1 with biloma after MWA. No marked chemotherapeutic agent-induced toxicity occurred. After chemotherapy or TACE, transient blood indicators and symptoms were observed as follows: myelosuppression, abnormal liver function, gross hematuria, fever, and abdominal pain. Transient symptoms after MWA were fever, abdominal pain, and massive gross hematuria. The present study demonstrates that MWA combined with TACE is a safe and effective method for treating unresectable hepatoblastoma in infants and children with controllable side effects.

Feasibility, safety, and efficacy of ultrasound-guided percutaneous microwave ablation for giant hepatic hemangioma

Background: Hepatic hemangioma is a common benign liver tumor. The majority of cases are asymptomatic and require no specific treatment. The aim of this study was to evaluate the feasibility, safety and efficacy of microwave ablation (MWA) for symptomatic or enlarging giant hepatic hemangioma (≥10 cm).Methods: From December 2013 to June 2016, 12 patients with giant hepatic hemangioma (≥10 cm) underwent ultrasound-guided percutaneous MWA, and ablation-related complications were observed. All patients were followed up with magnetic resonance or enhanced CT imaging at one month postoperatively to evaluate efficacy.Results: This study included a total of 13 giant hepatic hemangiomas (mean: 11.7 ± 1.6 cm) in 12 patients who initially underwent 16 sessions of MWA; three lesions were treated with two sessions of planned ablation. The average ablation time for a single hepatic hemangioma was 39.0 ± 14.4 minutes. Two patients had acute postoperative non-oliguric renal insufficiency without intra-abdominal hemorrhage, liver failure or other complications. Initially, complete ablation was achieved in ten lesions in nine patients (76.9%, 10/13). One patient underwent a second session of MWA at 5 months postoperatively due to fast growing residual tissue; complete necrosis was achieved after treatment. The remaining two cases did not receive any invasive treatment due to small residual volumes. The total complete ablation rate was 84.6% (11/13).Conclusion: Image-guided MWA is a safe, feasible, effective treatment for giant hepatic hemangioma; these findings may open a new avenue for treatment.

3:36 PM Abstract No. 175 Comparison of safety and efficacy of microwave ablation vs. radiofrequency ablation for hepatocellular carcinoma

3:36 PM Abstract No. 175 Comparison of safety and efficacy of microwave ablation vs. radiofrequency ablation for hepatocellular carcinoma

Computed tomography-guided percutaneous microwave ablation for treatment of peripheral ground-glass opacity-Lung adenocarcinoma: A pilot study.

The purpose of the study is to retrospectively evaluate the safety and efficacy of microwave ablation (MWA) for the treatment of ground-glass opacity (GGO)-lung adenocarcinoma. From December 2013 to June 2017, a total of 51 patients (22 males and 29 females, mean age of 69.4 ± 10.1 years) were included in this study, with 51 lung adenocarcinoma lesions showing GGO (mean long-axis diameter of 18.7 ± 6.05 mm). They received a total of 52 sessions of percutaneous computed tomography-guided (CT-guided) MWA. First, lung adenocarcinoma with GGO was histologically defined by needle biopsy under the guidance of CT. Second, the efficacy of CT-guided MWA was analyzed, including the feasibility, safety, 3 years local progression-free survival (LPFS), 3 years disease-specific survival, and 3 years overall survival (OS). Final, complications after MWA were also summarized. The technical success rate was 100%, without MWA procedure-related death. At the median follow-up period (27.02, range: 7-45 months), the rates of 3 years LPFS, cancer-specific survival, and OS were 98%, 100%, and 96%, respectively. The complications after MWA included pneumothorax (48.1%, 25/52), hemoptysis (28.8%, 14/52), pleural effusion (23.1%, 12/52), and pulmonary infection (7.7%, 4/52). CT-guided percutaneous MWA was a feasible, safe, and effective therapeutic approach for treating GGO-lung adenocarcinoma.

Microwave ablation: an effective treatment for mild-to-moderate secondary hyperparathyroidism in patients undergoing haemodialysis

Background: Microwave ablation (MWA) is an effective treatment for severe secondary hyperparathyroidism (SHPT), but it can also be used for mild-to-moderate secondary hyperparathyroidism (SHPT). In this randomised, controlled study, the efficacy of MWA in the treatment of mild-to-moderate hyperparathyroidism is investigated.Materials and methods: We assessed outcomes 12 months after the randomisation of 28 patients with mild-to-moderate SHPT. The subjects received either MWA plus calcitriol or calcitriol alone. The primary end-points were the rate of achieving target levels of intact parathyroid hormone (iPTH), changes in iPTH levels and the rate of patients developing severe SHPT.Results: Primary end points: the overall rates of achieving target levels of iPTH were comparable between the MWA and calcitriol alone groups (24% vs. 22%, p = 0.85). However, the rate of iPTH <150 pg/mL (lower limit of the target range) in the MWA group was higher than that in the calcitriol alone group (23% vs. 8%, p = 0.02). The mean iPTH level in the MWA group after MWA was lower than that in the calcitriol alone group (373.09 ± 322.31 vs. 552.28 ± 361.87 pg/mL, p < 0.001). There was a significant difference in the change in iPTH levels over time within the MWA group (p < 0.001) but not in the calcitriol alone group. Only one patient developed severe SHPT in the MWA group, while six patients in the calcitriol alone group developed severe SHPT (p = 0.04).Conclusions: Compared with calcitriol alone, MWA plus calcitriol decreases iPTH levels and prevents the progression of mild-to-moderate SHPT.

Microwave ablation combined with attenuated Salmonella typhimurium for treating hepatocellular carcinoma in a rat model.

We aim to investigate the safety and efficacy of microwave ablation (MWA) combined with attenuated Salmonella typhimurium strain VNP20009 in treating hepatocellular carcinoma. Portions of tumor tissues were orthotopically implanted in the livers of 40 male rats weighed 150~200 g to establish tumor models. Three weeks later, the rats were randomly divided into four groups: (A) MWA plus VNP20009 group; (B) MWA group; (C) VNP20009 group; and (D) control group. Incomplete MWA was performed (20~30 W, 1~2 min) after the hepatic carcinoma was properly exposed. VNP20009 (about 1×107 cfu) was directly injected into the tumor immediately. MRI scans were performed to assess the tumor responses 7 and 14 days later, respectively. Micro CT was used to observe the lung metastases. After the animals were sacrificed or died, the tumors were cut off for the purpose of pathological and immunohistochemical analyses. The results showed that the mean tumor volumes of MWA plus VNP20009 group on the 7th and 14th day post treatment were obviously smaller than those of other groups (P < 0.05). Lung metastases rates were 20%, 60%, 30% and 100% in MWA plus VNP20009 group, MWA group, VNP20009 group and control group, respectively. The median survival of the rats in MWA plus VNP20009 group was distinctly longer than those in other groups (P < 0.05). In summary, MWA combined with VNP20009 produced better effects than MWA or VNP20009 alone in treating hepatic carcinoma. This strategy might have potential ability to decrease lung metastases and prolong the overall survival.

Microwave ablation is effective against liver metastases from gastric adenocarcinoma

Purpose: The resection rate for liver metastases from gastric cancer is only 1.4–21.1%. This study aimed to evaluate the safety and therapeutic efficacy of microwave ablation (MWA) for liver metastases from gastric adenocarcinoma (LMGC).Materials and methods: A database of 108 gastric adenocarcinoma patients with liver metastases who underwent MWA (n = 32) or systemic chemotherapy (n = 76) for LMGC between 2008 and 2016 was reviewed. Overall survival curves were assessed and compared based on different therapies.Results: All the patients were followed up for a median of 15 months (range, 2–68 months). The median cumulative survival times of patients after MWA and systemic chemotherapy were 25 (95% confidence interval (CI) 16.5–33.5) months and 12 (95% CI 7.7–16.3) months, respectively (HR 1.751, 95% CI 1.077–2.845; p = .015). The 1-, 3-, and 5- year survival rates were 80.9%, 31.2%, and 16.7% (MWA group); and 50.0%, 18.8%, and 5.4% (chemotherapy group), respectively. In the MWA group, side effects were reported in eight patients who developed abdominal pain, transient fever, or nausea. Dominant size, number of liver metastases, therapeutic modalities, and presence of extrahepatic metastases showed significant prognostic value in univariate analyses; while the latter three were identified as independent prognostic factors in multivariate regression analysis.Conclusions: MWA is a safe and useful alternative for liver metastases from gastric adenocarcinoma in selected patients.

Percutaneous microwave ablation of 5-6 cm unresectable hepatocellular carcinoma: local efficacy and long-term outcomes

Objective: This study aims to evaluate the local efficacy and long-term outcomes of microwave ablation (MWA) for treating large unresectable hepatocellular carcinomas (HCCs).Methods: A total of 82 patients with 5-6 cm unresectable HCCs, who underwent a single MWA procedure during the period of January 2007 to July 2011, were retrospectively enrolled into this study. Percentages of technical success and complications of MWA and HCC local recurrence (LR) after MWA were determined. In addition, prognostic factors were screened and overall survival (OS) and recurrence-free survival (RFS) rates were estimated.Results: One-, three- and five-year OS rates in this MWA-treated cohort were 92.7, 63.4 and 41.1%, respectively; and the corresponding RFS rates were 65.9, 31.7 and 23.0%, respectively. Primary technical efficacy was 89.0% after the first round of ablation, three (3.7%) patients developed major complications, and LR rate was 20.7%. Child-Pugh classification (p < .001), tumour location (p = .049) and LR (p = .002) were independent factors associated with OS, as determined by multivariate analysis.Conclusions: MWA is safe and effective for the treatment of selected large HCCs, and provides an alternative treatment option for patients with unresectable HCCs. Furthermore, the favourable local efficacy of MWA could potentially improve long-term survival.