RFA group N = 47 Age (range): 58 (43–77) y Male/female: 40/7 Child’s grade A/B: 42/5 RFA Exclusion Macroscopic vascular bile duct invasion; patients with >2 tumours; tumours >6 cm Objectives To compare RFA and MTA by surgical approach USA) Kaplan–Meier method and compared with log-rank test P < 0.05 was significant Duration of follow-up 1 month, then 3-monthly during first 2 y, 6-monthly after 2 y Potretzke et al () USA Single-centre RHCC Recruitment: Level III-3 Quality: moderate RFA N = 55 Mean age (range): 32 (23–88) y Male/female: 40/15 MTA N = 99 Mean age (range): 61 (44–82) y Male/female: 81/18 Inclusion All patients who underwent percutaneous RFA or MTA between 2001 and 2013 for HCC Exclusion Patients who underwent TACE in combination with thermal ablation, or who underwent prior chemotherapy for HCC Objectives To compare local treatment of HCC efficacy and major complications between RFA and MTA systems RFA Percutaneous under general anaesthesia Internally water-cooled electrode and generator (Cool-tip; Covidien, Boulder, CO, USA) with single, cluster, or multiple electrodes in switched mode (Cool-tip Switching Controller; Covidien) MTA Percutaneous under general anaesthesia High-powered system with continuous in-phase output to to 3 antennae (Certus 140; NeuWave Medical, Inc, Madison, WI, USA) Outcomes Local tumour progression OS Complications Statistical analyses Kaplan–Meier compared with log-rank test for survival Cox’s proportional hazard model for risk differences Fine and Gray for risk analyses Statistics performed with R 3.1.0 (R Core Team, 2014 R Foundation for Statistical Computing, Vienna, Austria) Duration of follow-up Every 3 months for 1 y; thereafter Median follow-up: RFA—31 (1–148) months; MTA—24 (1–57) months RFA was used on all patients treated before 2011. All patients were treated with MTA from 2011 to 2013
Objectives Report complications encountered by members of a collaborative group performing MTA in patients with focal liver cancer Shimada et al () Japan Case series Level IV Quality: moderate N = 29 Male/female: 21/8 Mean age not reported for whole group; y Inclusion and exclusion criteria not reported Objectives Describe complications encountered using MTA MTA Open (n = 23) or percutaneous (n = 6) approach, using Microtase (Nippon Shoji, Osaka, Japan) 2450 MHz, 100 W for open and 60 W for percutaneous Ablation time 60 s Outcomes Complications Statistical analysis None undertaken Follow-up 11–55 months Old study Ierardi et al () Italy Case series Level IV Quality: moderate N = 25 Metastases from: CRC: 21 Breast: 2 Pharynx: 1 Oesophagus: 2 Retroperitoneal leiomyosarcoma: 1 Gallbladder: 2 Renal: 1 Pancreatic: 1 Male/female: 17/8 Mean age (range): 65.9 (49–83) y Inclusion Absence of or stable extrahepatic disease Inoperable lesions Tumour size >3 cm Lesions located near vessels with diameter >3 mm Exclusion Surgically treatable lesions or amenable to RFA (not described) Objectives To evaluate the technical success, effectiveness and safety of MTA to overcome the limits of RFA MTA: Percutaneous MTA (Evident, Covidien, USA) 915 MHz, 45 W Antenna 14.5-gauge (Evident MW Ablation Percutaneous Antenna), continuously with saline solution to avoid possible thermal damage All lesions treated with 2 or 3 antennae simultaneously Total ablation time 10 min Outcomes Technical success, disease-free survival, safety and efficacy Statistical analyses Kaplan–Meyer method for evaluation of survival Duration of follow-up Mean 12.04 months (range 3–36 months) - Liang et al () China Case series Level IV Quality: poor N = 74 Metastases from: CRC: 28 Inclusion None specified Exclusion MTA Ultrasound-Guided Microwave Coagulator-I Outcomes Survival, complications Statistical analyses 16 patients eligible for resection elected to have MTA 62.7
Gastric/cardiac: 12 Breast: 11 Lung: 12 Pancreatic: 1 Gallbladder: 2 Renal: 5 Ocular melanoma: 1 Small bowel leiomyosarcoma: 2 Male/female: 44/30 Age (range): 27–81 y (no mean reported) None specified Objectives To examine predictors of survival in patients undergoing MTA for liver metastases (PLA General Hospital and Institute 207 of the Aerospace Industry Company, Beijing, China) 2450 MHz, 10–80 W Survival rates calculated using Kaplan–Meier method; predictive factors compared with log-rank test; multivariate Cox’s proportional hazards model Duration of follow-up Mean 25.1 ± 11.4 months, range 5–83 months Abe et al () Japan Case series Level IV Quality: moderate N = 8 All breast metastases All female Mean age (range): 49.0 (41–69) y Inclusion Limit of 5 lesions in each patient Lesions <3 cm diameter Exclusion Major coagulation disorders and hepatic failure Objectives To evaluate the efficacy of MTA for local control of liver metastases from breast cancer MTA Microwave coagulator (Microtase, OT-110M, Osaka, Japan) 2.45 GHz, 60 W Ablation duration 60 s, usually 3 ablations at each point MRI guided Outcomes Treatment efficacy, side-effects, complications Statistical analyses None undertaken Duration of follow-up Mean 25.9 months (range 1–43 months) 4 patients had only liver metastases, 4 had liver and other metastases Focus of paper was on imaging rather than intervention Li et al () China Case series Level IV Quality: moderate N = 18 Nasopharyngeal metastases Male/female: 15/3 Mean age (range): 45.7 (31–61) y Single metastasis in n = 14, 2 metastases in n = 3, 4 metastases in Inclusion Karnofsky performance status >80 Max 5 liver lesions Failure of previous chemotherapy or ineligible for chemotherapy Local control of primary tumour by radiation therapy Local control or absence of extrahepatic metastases MTA Percutaneous MTA Qinghai Microwave Electronic Institute, Nanjing, China) 14-gauge cooled-shaft antenna Power 50–60 W Cumulative ablation time Outcomes Survival; complications Statistical analyses Kaplan–Meier survival curves Duration of follow-up 22.4 months (range 4–52 months) -
{Also includes pop 1 data} Quality: moderate CRC = 18 Gynaecologic = 13 Breast = 10 Gastric = 9 Lung = 8 Prostate = 2 Oesophageal = 1 Male/female: not reported by cancer type Age: not reported by cancer type refusal Tumour accessible via percutaneous approach ≤3 hepatic lesions with max diameter of 4 cm Absence or portal vein thrombosis or extrahepatic metastases Prothrombin time of <25 s Prothrombin activity >40% Platelet count >40 cells × 109/L Exclusion New lesions found after previous MTA, TACE, RFA or other therapy Also received immunotherapy Lost to follow-up Objectives To compare patients undergoing MTA at sites close to and further away from the diaphragm. Some data are provided for outcomes relevant to pop 2 Nanjing, China) 2450 MHz, 1–100 W Cool-shaft antenna Max 3 sessions Total treatment time s recurrence Statistical analyses None undertaken Duration of follow-up Not reported separately for pop 2; for 2 groups compared in the study (close to and further from diaphragm), follow-up was 11.5 ± 10.3 months and 12.7 ± 9.6 months, respectively the aim of this study; it provided some data so has been included on that basis Alexander et al () USA {Also includes pop 1 data} Case series Level IV Quality: moderate N = 39 Metastases from: CRC = 27 Breast = 4 Carcinoid = 2 Lung = 2 Melanoma = 2 CCA = 1 Anal = 1 Mean age ± SD: Inclusion Single liver neoplasm Refused or not suitable for resection Exclusion Radiographic evidence of nodal disease Adenopathy Extrahepatic disease International normalised ratio of >1.8 on day of ablation MTA Percutaneous or intraoperative Five different machines used: either 915 MHz (Evident, Covidien, USA’ MicroThermX, BSD Medical, USA; AveCure, MedWaves, USA) or 2450 MHz (Certus 140, NeuWave, USA; Amica, Hospital Service, Outcomes Survival Statistical analyses Kaplan–Meier analysis Duration of follow-up: Not reported, but results provided for survival at 1 year Some patients also had resection, but numbers not reported
CRC group: 68.4 ± 2.4 y Other: 68.6 ± 3.7 y Male/female: not reported by cancer type Objectives Evaluate safety and efficacy of MTA in treating solitary primary and metastatic liver tumours Italy) Cooled-shaft antennae Yu et al () China {Also includes pop 1 data} Case series Level IV Quality: moderate N = 307 Metastases from: Gastrointestinal = 387 Breast = 47 Lung = 44 Pancreas = 38 Extrahepatic CCA = 37 Ovarian = 26 Other = 74 Male/female not reported for pop 2 Age not reported for pop 2 Inclusion Single lesion ≤8 cm ≤3 lesions ≤4 cm Normal serum total bilirubin Normal albumin level Platelet count >50 × 109/mm3 Prothrombin activity >50% Exclusion Portal vein thrombosis or extrahepatic metastases Objectives Elucidate incidence of local tumour recurrence after percutaneous MTA; evaluate risk factors Percutaneous MTA Kangyou Medical, Nanjing, China) 915 and 2450 MHz, 50–60 W Cooled antennae Outcomes Local tumour recurrence Statistical analysis Kaplan–Meier analysis Duration of follow-up Median 20.3 months, range months - CCA = cholangiocarcinoma; CRC = colorectal cancer; HCC = hepatocellular carcinoma; MRI = magnetic resonance imaging; MTA = microwave thermal ablation; MTA = microwave tissue ablation; TACE = transcatheter arterial chemoembolisation; RFA = radiofrequency ablation; SD = standard deviation; SPSS = Statistical Package for Social Sciences 2000,
observed OS 1 y K = 1 RCCC, N = 89 Very serious Not serious Not serious Not serious Confounding would suggest spurious effect, but no effect was observed MTA 82.4 vs RFA 86.6% patients Low ⊕⊕⨀⨀ Critical 8/9 OS 2 y K = 1 RCCC, N = 89 Very serious Not serious Not serious Not serious Confounding would suggest spurious effect, but no effect was observed MTA 66.9% vs RFA 54.8% patients Low ⊕⊕⨀⨀ Critical 8/9 OS 3 y K = 1 RCCC, N = 89 Very serious Not serious Not serious Not serious Confounding would suggest spurious effect, but no effect was observed MTA 55.8% vs RFA 44.3% patients Low ⊕⊕⨀⨀ Critical 8/9 OS 5 y K = 1 RCCC, N = 89 Very serious Not serious Not serious Not serious Confounding would suggest spurious effect, but no effect was observed MTA 44.0% vs RFA 31.7% patients Low ⊕⊕⨀⨀ Critical 8/9 Complete ablation K = 1 RCCC, N = 89 Very serious Not serious Not serious Not serious Confounding would suggest spurious effect, but no effect was observed MTA 93.5% vs RFA 84.3% patients, P = 0.094 Low ⊕⊕⨀⨀ Critical 8/9 MTA = microwave tissue ablation; OS = overall survival; RCCC = retrospective concurrent control cohort; RFA = radiofrequency ablation; RHCC = retrospective historical control cohort