High-frequency versus low-frequency microwave ablation in malignant liver tumours: evaluation of local tumour control and survival

Purpose: To compare local tumour control and survival rates in patients with liver metastases treated with microwave ablation (MWA), using either a low-frequency (LF) (915?MHz) or high-frequency (HF) system (2.45?GHz).

Materials and methods: The retrospective study included 221 patients (mean age: 61.7 years) with 356 malignant hepatic lesions. Ninety-four patients with 133 lesions underwent LF-MWA between September 2008 and February 2011, while 127 patients with 223 lesions were treated with HF-MWA between March 2011 and July 2013. MRI was performed after 24?h from each procedure and at 3, 6, 9, 12, 18 and 24 months post-ablation. Both groups were compared with the Fisher’s exact test. Survival rates were calculated using the Kaplan–Meier test.

Results: The mean initial ablation volume of LF-MWA was nearly half of HF-MWA (19.1?mL vs. 39.9?mL). The difference in volume between both systems was significant (p?p?=?.00059). The 1-, 2- and 4-year overall survival rates for curative indication were 98.9%, 95.7% and 82.9% for LF-MWA, respectively, and were 100%, 97.6% and 92.9% for HF-MWA, respectively. The difference in survival rates was not significant (p?>?.05).

Conclusion: Both LF- and HF-MWA systems are effective treatment options for oligonodular liver malignant lesions, but significantly higher ablation volumes, longer time to progression and lower progression rates were observed in HF-MWA.     

Prognostic factors for local and distant control in Ewing sarcoma family of tumors.

BACKGROUND: Advances in the treatment of Ewing sarcoma family of tumors (ESFT) are the result of improvements in systemic and local therapies. The individual contributions of each treatment component cannot be analyzed separately; improvements in local and systemic control can influence each other. PATIENTS AND METHODS: We reviewed the records of 220 patients treated on institutional protocols from 1979 to 2004. Factors predictive of local and distant recurrence were analyzed. RESULTS: The median age at diagnosis was 13.7 years. Ninety-five patients relapsed at a median of 1.6 years. The 5-year overall survival estimate was 63.5% +/- 3.5%. The estimated 5-year cumulative incidence (CI) of local failure was 25.1% +/- 3.0%. Local failure was associated with treatment era (P < 0.001), tumor size (P = 0.037) and type of local control (P = 0.021). Systemic treatment intensification improved local control. The estimated 5-year CI of distant recurrence was 22.5% +/- 2.9%. Patients with localized disease (P < 0.001), smaller tumors (P = 0.018) and those who received surgery +/- radiation for local control (P = 0.023) had lower CI of distant failure. CONCLUSIONS: Successful treatment of ESFT requires optimal systemic and local therapy. Both treatment modalities are intertwined and the control of both local and distant disease is the result of the combined approach.     

Radiofrequency and microwave ablation of lung tumors

Lung cancer is the most common cause of cancer‐related mortality in the United States. Surgical resection remains the standard treatment for early stage, non‐small cell lung cancer, and limited pulmonary metastases. However, many patients with resectable disease have significant co‐morbidities which preclude surgical resection. Radiofrequency and microwave ablation are emerging modalities of treatment for these high‐risk patients. Here, we review the principles, common devices in use, and treatment results of ablative therapy for lung tumors. J. Surg. Oncol. 2009;100:645–650. © 2009 Wiley‐Liss, Inc.     

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.     

The local efficacy and influencing factors of ultrasound-guided percutaneous microwave ablation in colorectal liver metastases: a review of a 4-year experience at a single center

Purpose: To investigate the clinical effectiveness and safety of ultrasound (US)-guided percutaneous microwave ablation (MWA) for colorectal liver metastasis (CRLM) and evaluate the influencing factors of local efficacy.

Methods: From January 2013 to January 2017, 137 CRLM patients accepting US-guided percutaneous MWA were included. The 2450-MHz microwave ablation system and a cooled-shaft antenna were used. All patients were regularly followed up for at least 6?months. Technical success, complete ablation, local tumor progression (LTP), complications and side effects were assessed. Logistic regression analysis was used to identify the independent prognostic factors for LTP.

Results: In total, 411 lesions (mean diameter 15.4?±?7.2?mm, range 5–67?mm) were treated. Complete ablation was achieved in 99.27% (408/411) of lesions and 97.81% (134/137) of patients. LTP occurred in 5.35% (22/411) of lesions and 16.06% (22/137) of patients. LTP was more likely to occur in lesions larger than 3?cm in diameter (OR: 14.71; p?<?.001; 95% CI: 3.7 3–57.92), near a large vascular structure (OR: 7.04; p?<?.001; 95% CI: 2.41–20.60), near the diaphragm (OR: 4.02; p?=?.049; 95% CI: 1.05–16.11) and in patients with no response to chemotherapy before MWA (OR: 3.25; p?=?.032; 95% CI: 1.14–15.30). MWA was well tolerated, with a major complication rate of 3.65%, a minor complication rate of 8.03% and a mortality rate of 0%. Fever and pain were the most common side effects after MWA.

Conclusions: US-guided percutaneous MWA of CRLM is a safe and effective method that is expected to become a routine treatment for local tumor control of CRLM.     

腹腔镜辅助下微波固化术治疗特殊部位肝癌的临床体会

目的:探讨腹腔镜辅助下微波固化术在治疗特殊部位肝癌中的临床意义.方法:对我科2011年01月至2012年06月住院行腹腔镜辅助下肝癌微波固化术的45例患者资料总结,分析术后并发症的发生情况.结果:各病例均未出现出血导致的介入止血及开腹手术止血、空腔脏器穿孔导致腹腔感染、气胸、血胸等手术相关并发症.结论:腹腔镜辅助下微波固化术在治疗特殊部位肝癌中有重要的临床应用价值.     

Evaluation of microwave ablation of liver malignancy with enabled constant spatial energy control to achieve a predictable spherical ablation zone

Objectives: To evaluate the clinical performance of a new microwave ablation (MWA) system with enabled constant spatial energy control (ECSEC) to achieve spherical ablation zones in the treatment of liver malignancies.

Materials and methods: In this retrospective study, 56 hepatic tumours in 48 patients (23 men, 25 women; mean age: 59.6 years) were treated using a new high-frequency MWA-system with ECSEC. Parameters evaluated were technical success, technical efficacy, tumour diameter, tumour and ablation volume, complication rate, 90-day mortality, local tumour progression (LTP) at the 12-month follow-up, ablative margin and ablation zone sphericity. These parameters were compared using the Kruskal–Wallis test with the same parameters collected retrospectively from cohorts of patients treated with conventional high-frequency (HF) MWA (n?=?20) or low-frequency (LF) MWA (n?=?20).

Results: Technical success was achieved in all interventions. The technical efficacy was 100% (ECSEC) vs. 100% (LF-MWA) vs. 95% (HF-MWA). There were no intra-procedural deaths or major complications. Minor complications occurred in 3.57% (2/56), 0% (0/20) and 0% (0/20) of the patients, respectively. The one-year mortality rate was 16.1% (9/56), 15% (3/20) and 10% (2/20), respectively. The LTP was 3.57% (2/56), 5% (1/20) and 5% (1/20), respectively. The median deviation from ideal sphericity (1.0) was 0.135 (ECSEC) vs. 0.344 (LF-MWA) vs. 0.314 (HF-MWA) (p?p?Conclusions: Microwave ablation of liver malignancies is a safe and efficient treatment independent of the system used. Hepatic MWA with ECSEC achieves significantly more spherical ablation zones and higher minimal ablative margins.     

Microwave ablation in treating intrahepatic recurrence of hepatocellular carcinoma after liver transplantation: An analysis of 11 cases

Abstract

Purpose: This study was designed to evaluate the efficacy and safety of microwave ablation (MWA) in the treatment of intrahepatic recurrence of hepatocellular carcinoma (HCC) after liver transplantation. Materials and methods: Between October 2008 and August 2014, a total of 11 cases with 19 lesions were enrolled. All the subjects had confirmed HCC recurrence after liver transplantation by at least two types of enhanced imaging. Real-time monitoring and small ethanol doses were used as an additional technique to assist with ablation. Contrast imaging was performed to evaluate the technique efficacy. The technique efficacy rate, local tumour progression rate, 3, 6, 9, 12, 18 and 24 months survival rates, and the incidence of complications were comprehensively analysed. Results: The follow-up period ranged from 5–33 months. All tumours achieved full ablation. The first MWA technique efficacy rate was 84.2% (16/19), while the second technique efficacy rate was 100%. Local tumour progression was identified in three cases (15.8%) at 1, 3 and 7 months after MWA. The 3, 6, 9, 12, 18 and 24 months accumulative survival rates were 90.9%, 81.8%, 71.6%, 51.5%, 30.7% and 15.3%, respectively, the average survival time was 17.3 months (3.5–33 months). Mild side effects included five patients (45.4%) with fevers, three with (27.3%) nausea and vomiting, five (45.4%) with local pain, and eight (72.7%) with increased blood transaminase levels; no serious complications occurred. Conclusion: MWA treatment is a promising technique for intrahepatic recurrence after liver transplantation without serious complications or side effects.     

CT-guided percutaneous microwave ablation of adrenal malignant carcinoma: preliminary results

BACKGROUND:

Microwave ablation has recently been developed as a safe and effective treatment for a variety of tumors. The authors evaluated the safety and efficacy of computed tomography (CT)‐guided percutaneous microwave ablation of adrenal malignant tumors.

METHODS:

Nine patients between 41 and 83 years of age (average age, 54 years) with adrenal carcinoma (a total of 10 lesions) received CT‐guided percutaneous water‐cooled microwave ablation. The 9 cases included 1 primary adrenocortical carcinoma and 8 metastatic carcinomas (4 from lung cancer, 2 from hepatocellular carcinoma, 1 from intrahepatic cholangiocarcinoma, and 1 from left tibial osteosarcoma). Of the 8 metastatic cases, 7 were unilateral, and 1 was bilateral. All cases were pathologically confirmed by aspiration biopsy or postsurgical biopsy. The tumor diameters ranged from 2.1 cm to 6.1 cm (average, 3.8 cm). The average number of ablation sites was 1.5 sites (1‐3 sites), and the average accumulated ablation time was 7.7 minutes (4‐15 minutes). The procedures were performed using a cooled‐shaft antenna.

RESULTS:

The patients were followed for 3‐37 months, with an average of 11.3 months. Nine of 10 lesions were completely necrotized after first treatment. The other lesion was completely necrotized after 2 treatments. One of the patients experienced hypertensive crisis during treatment. No patient experienced recurrent tumor at the treated site, and this lack of recurrence indicated effective local control. All patients had progression of metastatic disease at extra‐adrenal sites.

CONCLUSIONS:

CT‐guided percutaneous water‐cooled microwave ablation is a minimally invasive and effective method for the treatment of adrenal carcinoma. Cancer 2011;. © 2011 American Cancer Society.     

射频消融及125I粒子植入在预防肝癌切除术后局部复发的作用

目的探讨降低原发性肝癌切除术后局部复发的方法,提高肝癌患者的长期生存率。方法78例肿瘤靠近第一、第二肝门,估计切缘距肿瘤<1cm的肝癌患者,按就诊单双日分为单纯切除组和联合组。单纯切除组38例,仅行常规肝癌切除;联合组40例,在肝癌切除后,切缘行射频消融和~(125)I粒子植入。全部患者术后均定期随访。结果联合组术后1、3、5年肿瘤复发率分别为7.5%、30.0%和45.0%,术后1、3、5年生存率分别为92.5%、67.5%和30.0%,与单纯切除组比较,其中3、5年复发率差异有统计学意义((x~2=7.340,P<0.01;x~2=15.740,P<0.01);联合组的3、5年生存率较单纯切除组呈现明显升高的趋势。结论肝癌切除后切缘射频消融和~(125)I粒子植入能有效地降低术后局部复发率,提高治疗效果,且有可能延长肝癌患者的生存期。     

Risk factors of local recurrence after surgery in extraabdominal desmoid‐type fibromatosis: A multicenter study in Japan

This study was undertaken to clarify the risk factors, including the mutation status of CTNNB1, for the local recurrence after surgery of the rare disease desmoid‐type fibromatosis. It was designed as a multiinstitutional joint research project with 7 major centers in Japan participating. The committee members of 7 major medical centers specializing in bone and soft tissue tumors formed this study group to develop clinical care guidelines. Of 196 cases with specimens and medical records collected from the 7 institutions, 88 surgically treated ones were analyzed regarding clinicopathologic prognostic factors including CTNNB1 mutation status. Excluding R2 cases (n = 3), 5‐year local recurrence‐free survival (LRFS) was 52.9%. No case had received pre‐ or postoperative radiotherapy. Univariate analysis revealed that extremity location (P < .001) and larger size (8 cm or more, P = .036) were significant adverse risk factors for LRFS. Multivariate analysis indicated that extremity location (P < .001) was a significantly adverse factor in addition to recurrent tumor (P = .041), S45F mutation (P = .028), and R1 surgical margin (P = .039). Preoperative drug treatment, including nonsteroidal antiinflammatory drugs, did not reduce the incidence of local recurrence (P = .199). This is the first study to analyze the factors correlating with outcomes of surgical treatment, including CTNNB1 mutation status, in a relatively large number of cases from an Asian country. Tumor location was found to be the most influential prognostic factor for local recurrence, similar to the results from Europe and North America. The development of more sensitive method(s) for determination of CTNNB1 mutation is a priority for future study.     

Impact of timing and cycles of systemic chemotherapy on survival outcome of colorectal liver metastases patients treated by percutaneous microwave ablation

Purpose: The aim of this retrospective study is to determine the optimal timing and number of cycles of systemic chemotherapy in patients with colorectal liver metastases (CLM) treated by ultrasound-guided percutaneous microwave ablation (PMWA).

Materials and methods: In total 199 patients with 318 CLM, median number of tumours one per patient and median maximum size of tumours 3.0?cm, treated by PMWA combined with or without systemic chemotherapy were included in our study. Chemotherapy was administered pre-ablatively in 148 of those patients (74.4%), and post-ablatively in 142 (73.6%). Chemotherapy regimens included FOLFOX/XELOX, FOLFIRI/XELIRI, and sequential monotherapy. Prognostic factors were evaluated by univariate and multivariate analyses, using log-rank test and Cox proportional hazards model, respectively.

Results: The estimated 5-year rates of progression free survival (PFS) and overall survival (OS) were 10.1% and 27.9%, respectively. The number of CLM (P?=?0.003), maximum size of CLM (P?<?0.001) and topography (P?=?0.030) were independent prognostic factors for PFS of patients with CLM while age (P?=?0.002), maximum size of CLM (P?=?0.006) and post-ablative chemotherapy (P?=?0.046) for OS. In further analysis, CLM patients receiving more than six cycles of post-ablative chemotherapy had significantly better OS (P?=?0.015) than those without post-ablative chemotherapy.

Conclusion: This study revealed chemotherapy administered after (more than six cycles) PMWA improved the OS of CLM patents. And, PMWA was a safe procedure in view of the absence of procedure-related death and low rate of major complications.     

Feasible temperature of percutaneous microwave ablation of dog liver abutting the bowel

Purpose: This study used a dog model to determine the optimal temperature of percutaneous microwave ablation that causes complete necrosis of liver but not the adjacent bowel, supporting the use of this method to specifically and effectively treat liver tumour abutting the bowel.

Materials and methods: Ultrasound-guided percutaneous microwave ablation of liver abutting the bowel was performed on healthy adult dogs. Temperature of the ablation margin was monitored and controlled through inserted thermal monitoring needles. Dogs were divided into three groups and received microwave ablation at 75–95°C, 65–75°C, or 55–65°C. Imaging and histological examination were used to evaluate the damage of the bowel adjacent to the ablated liver.

Results: Within one hour of treatment, the bowel adjacent to the ablated liver was seriously burned in the group receiving 75–95°C microwave ablation. Inflammation and congestion were found in the submucosa of the bowel in the group receiving 65–75°C microwave ablation. Minor inflammation was found in the mucosa of the bowel in the group receiving 55–65°C microwave ablation. Moreover, in the group receiving 55–65°C microwave ablation, ablated liver areas were covered with omenta, and histological examination revealed inflammatory reaction of the omenta 28 days after ablation.

Conclusions: Microwave ablation at 55–65°C for 6?min is preferred for ablation of liver tissue abutting the bowel in dogs. These findings may provide some valuable reference for percutaneous microwave ablation of human liver tumour adjacent to the bowel.     

Local recurrence and local control of non-metastatic osteosarcoma of the extremities: a 27-year experience in a single institution

BACKGROUND: Indications and contraindications for limb salvage versus amputation for local treatment of osteosarcoma of the extremity are still controversial. PATIENTS AND METHODS: Patients (1,126) with non-metastatic osteosarcoma of the extremity, treated in a single institution between 1972 and 1999 with different protocols of adjuvant and neoadjuvant chemotherapy were evaluated to establish factors that could influence local recurrence (LR) and outcome. RESULTS: The 5-year event-free survival and overall survival were 55% and 66%. At a follow-up ranging between 5.5 and 32.5 years (mean18.6 years) of the 1,126 evaluated patients, 607 (54%) remained continuously disease-free and 519 relapsed. LR developed in 61 patients (5.4%) after a median time of 2.3 years (0.2-17). For this group of patients the 5-year post-relapse event-free survival and overall survival from the last relapse were, respectively, 11.4% and 16.4%. At the multivariate analyses only surgical margins and histologic response to preoperative treatment resulted to be independent prognostic factors for LR. CONCLUSION: Considering the risk of LR after surgery with inadequate surgical margins and poor prognosis of LR in osteosarcoma, limb salvage procedures should be performed only when adequate margins surgical margins can be achieved. In case of inadequate margins, an immediate amputation should be considered.     

Supplementary granulocyte macrophage colony‐stimulating factor to chemotherapy and programmed death‐ligand 1 blockade decreases local recurrence after surgery in bladder cancer

Despite advances and refinements in surgery and perioperative chemotherapy, there are still unmet medical needs with respect to radical cystectomy for muscle‐invasive bladder cancer (MIBC). We investigated the potential benefit of supplementary granulocyte macrophage colony‐stimulating factor (GM‐CSF) to chemoimmunotherapy with programmed cell death protein‐1 (PD‐1)/programmed death‐ligand 1 (PD‐L1) axis blockade and standard neoadjuvant chemotherapy in bladder cancer. We inoculated 2 × 10⁵ MBT2 cells s.c. in C3H mice to create a syngeneic animal model of local recurrence (LR). When the tumor diameter reached 12 mm, the mice were allocated randomly as follows: (i) non‐treated control (vehicle only); (ii) anti‐mPD‐L1 monotherapy; (iii) mGM‐CSF monotherapy; (iv) anti‐mPD‐L1 plus mGM‐CSF; (v) gemcitabine and cisplatin (GC); (vi) GC plus anti‐mPD‐L1; (vii) GC plus mGM‐CSF; and (viii) GC plus anti‐mPD‐L1 plus mGM‐CSF. After completing 2‐week neoadjuvant therapy, tumors were resected for resection margin evaluation and immunohistochemical staining and blood was collected for flow cytometry and ELISA. Operative wounds were sutured, and the operative site was monitored to detect LR. Addition of anti‐mPD‐L1 and mGM‐CSF to neoadjuvant GC chemotherapy enhanced the antitumor effect and reduced positive resection margins (50% vs 12.5%). Combination of GC, anti‐mPD‐L1, and mGM‐CSF resulted in longer LR‐free survival and cancer‐specific survival compared to those in other groups. These effects involved an immunotherapy‐related decrease in oncological properties such as tumor invasion capacity and epithelial‐mesenchymal transition. mGM‐CSF significantly decreased the accumulation of myeloid‐derived suppressor cells in both the blood and tumor microenvironment and blood interleukin‐6 levels. Supplementary GM‐CSF to neoadjuvant GC plus PD‐L1 blockade could decrease LR after radical surgery by immune modulation in the blood and tumor microenvironment.