Microwave Ablation For Liver Metastases Research Articles

PD-1 blockade combined with chemotherapy and bevacizumab in DNA mismatch repair-proficient/microsatellite stable colorectal liver metastases.

Single-agent immunotherapy is less effective in patients with DNA mismatch repair-proficient/microsatellite stable (pMMR/MSS) metastatic colorectal cancer (mCRC). Whether pMMR/MSS mCRC patients benefit from combination immunotherapy remains unclear. This study aimed to evaluate the efficacy and safety of anti-programmed cell death protein 1 (PD-1) therapy combined with chemotherapy and bevacizumab in pMMR/MSS colorectal liver metastases (CRLM) patients. A total of 12 patients with pMMR/MSS CRLM treated at The Sixth Affiliated Hospital of Sun Yat-sen University were enrolled. All patients were treated with at least 4 doses of PD-1 monoclonal antibody combined with chemotherapy and bevacizumab as neoadjuvant/adjuvant therapy. A total of 10 of the 12 patients received the combined therapies before primary tumor resection; the disease control rate (DCR) was 100% (10/10), and the objective response rate (ORR) was 70% (7/10). The ORR of liver metastases was 75% (9/12). Pathological complete response (pCR) was achieved in 1 primary tumor patient and 2 patients with hepatic lesions. A total of 5 patients underwent simultaneous resection of the primary tumor and liver metastases; 9 patients underwent microwave ablation for liver metastases. A total of 7 patients were assessed as having no evidence of disease (NED) with a median progression-free survival (PFS) interval of 9.2 (1.5-15.8) months after multimodality treatments for both primary and metastatic lesions. No severe immune-related adverse events (irAEs) and operational complications were observed. PD-1 blockade combined with chemotherapy and bevacizumab might be safe and effective for patients with pMMR/MSS CRLM. This treatment strategy might lead to better tumor regression and a higher chance of achieving NED.

Radiofrequency and microwave ablation controls hepatic oligoprogression of advanced gastroenteropancreatic neuroendocrine tumors.

In progression of multifocal liver metastases of gastroenteropancreatic neuroendocrine tumors (GEP-NET) escalation of systemic therapy is indicated. The aim of this retrospective study was to investigate the potential of local thermal ablation in hepatic oligoprogression and otherwise stable disease in GEP-NET. Patients with hepatic oligoprogression and otherwise stable disease, who underwent radiofrequency ablation (RFA) or microwave ablation (MWA) for local control, were included in the study. Thermal ablation was performed while maintaining the ongoing systemic therapy or without addition of a systemic therapy. The effectiveness of this therapeutic approach was evaluated by determination of local treatment success, improvement of progression-free survival (PFS) and the safety. Seventeen thermal ablation procedures were performed in 13 patients with well differentiated NET including seven ileum NET, four pancreatic NET, one appendix NET and one rectum NET. RFA and MWA of liver metastases were well tolerated without major complications. Thermal ablation resulted in an estimated median PFS of 62.6 weeks (mean 50.5 weeks; range 10.1-78.9 weeks) per procedure. In four patients, two ablation procedures were performed throughout the course of their disease resulting in an estimated median PFS of 69.1 weeks (mean 71.6 weeks; range 10.1-123.1 weeks) per patient. Start or change of systemic therapy could be delayed up to 123.1 weeks by using thermal ablations for isolated progression of single liver metastases. 88% of thermal ablations prolonged PFS. Thermal ablation of liver metastases in a non-curative intent has the potential to provide focal growth control and to prolong PFS in GEP-NET patients with hepatic oligoprogression.

2450-MHz microwave ablation of liver metastases under 3.0 T wide-bore magnetic resonance guidance: a pilot study

To investigate the feasibility and effectiveness of 3.0 T wide-bore magnetic resonance (MR)-guided microwave ablation (MA) of liver metastases (LM). From October 2018 to May 2020, 39 patients with 63 LM were treated with 3.0 T wide-bore MR-guided 2450-MHz MA therapy. The procedure parameters, technical success, complications, biochemical index changes, local tumor response, local tumor progression (LTP), 12-month disease-free survival (DFS) and 12-month overall survival (OS) were recorded and analyzed. The mean tumor maximum diameter and total procedure time were 3.0 cm and 55.2 min, respectively. Technical success was 100%, but 5 cases (12.8%) had grade-1 complications. Alanine transaminase, aspartate transaminase and total bilirubin showed a slight transient increase on day 3 (P < 0.05) and returned to normal by day 30 (P > 0.05). The complete ablation rates for ≤ 2.5 and > 2.5 cm lesions were 100% and 92.5%, respectively. During the median follow-up of 12.0 months, the LTP rate was 4.8% (3/63), and the 12-month DFS and OS rates were 61.3% and 92.2%, respectively. 3.0 T wide-bore MR-guided MA for LM is a safe and effective approach, especially for small LM.

PD-1 blockade combined chemotherapy and bevacizumab in DNA mismatch repair-proficient/microsatellite stable colorectal liver metastases.

e15547 Background: Although PD-1 blockade has been recommended as the first line treatment in DNA mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer (mCRC), it is worthwhile to investigate whether mCRC with DNA mismatch repair-proficient/microsatellite stable(pMMR/MSS) tumors benefit from a combination treatment with PD-1 blockade. Methods: In this cohort, ten patients with pMMR/MSS colorectal liver metastases (CRLM) treated in the 6th Affiliated Hospital of Sun Yat-sen University were enrolled. All the patients were exploratively treated with at least four doses of PD-1 monoclonal antibody combined with chemotherapy and bevacizumab as neoadjuvant/adjuvant therapy. The aim of the study was to evaluate the short-term efficacy and safety of this combined strategy. Results: All the 10 patients were confirmed pMMR/MSS by IHC or next generation sequencing (NGS). Eight of the 10 patients accepted the combined therapies before primary tumor resections, disease control rate (DCR) was 100% (8/8) and objective response rate (ORR) was 62.5% (5/8). The ORR of liver metastases was 70% (7/10) after this treatment. Pathologic complete response (pCR) was achieved in one patient’s primary tumor and was also achieved in another patient’s hepatic lesion. Four patients underwent simultaneous resection of primary tumor and liver metastases. Nine patients underwent microwave ablation for liver metastases. Five patients were assessed no evidence of disease (NED) with a median progress-free survival (PFS) of 5.0 (4.2-9.9) months after multimodality treatments for both primary and metastatic lesions. No immunotherapeutic associated sever adverse event (SAE) or operational complications were found in this cohort. Conclusions: PD-1 blockade combined chemotherapy and bevacizumab was safe and effective for patients with pMMR/MSS CRLM, which might lead to better tumor regression as well as more chances of NED. Further clinical phase II studies of evaluation of long-term efficacy of this combined strategy was needed.

Biliothoracic Fistula after Microwave Ablation of Liver Metastasis : Literature Review.

Microwave ablation is a safe and effective interventional approach, widely used in the treatment of unresectable primary or metastatic hepatic lesions. Thoracobiliary fistula is a rare postablation complication that can be treated with a conservative or surgical approach. We reviewed aetiology, pathogenesis, clinical picture, diagnostic possibilities, and therapeutic options for biliothoracic fistula developed after microwave ablation of liver metastasis. Furthermore, we reported our experience of successful conservative management of a nonhealing thoracobiliary fistula occurred after percutaneous thermal ablation of colorectal cancer liver metastasis. Our case supports a conservative approach based on percutaneous biliary system decompression and synthetic glue embolization for the treatment of combined biliopleural and biliobronchial fistula.

Capsule and Ablation Tract Related Features of Local Recurrence in Ultrasound Guided Microwave Ablation of Liver Metastases

Aim: To evaluate the capsule and ablation tract related features of local recurrence after ultrasound (US) guided percutaneous microwave ablation (MWA) of the liver metastases independently.&#x0D; Methods: Between February 2016 and December 2019, 101 patients with US-guided percutaneous MWA of the liver metastases were analyzed. Nineteen patients having thirty-two ablated lesions with local recurrence (LR) were included in the study. Histopathologic type of tumor, preablative features of the lesions and the ablation procedure data were noted. Tumor size, the closest distance between the lesion and the liver capsule was measured. The site of LR related to the liver capsule and related to ablation tract and the shape of the LR were noted&#x0D; Results: The median time of LR was 8.46±4.54 months (range, 3-20). The patient (n=19) and the ablated lesion (n=32) depended LR rates were 19% and 20% respectively. All LR of the parenchymal localized metastatic lesions originated from either tip or the side of the ablation tract and this relationship was found as statistically significant (p=0.035). no statistically significant relationship was found between vessel closeness and shape of LR (p=0,704) and between the site and the shape of LR (p=0.683). &#x0D; Conclusion: We defined some features of LR related to the ablation tract and liver capsule independently such as the relation between the recurrence and the blood vessel proximity, side of the LR throughout the ablation tract and its relation with the liver capsule.

The Application of Laparoscopic B-Ultrasound Microwave Ablation Technology in Liver Metastasis of Colorectal Cancer

Liver is the most common metastasis target organ in the late stage of colorectal cancer. More than 50% of colorectal cancer patients will have simultaneous or heterochronous liver metastasis. The survival time of patients with colorectal cancer and liver metastasis (CRLM) is short; not all patients can get radical resection of liver metastasis. For this part of patients, microwave ablation technology has been proved to be one of the effective methods for the treatment of liver metastasis. Laparoscopic B-ultrasound ablation also highlights a lot of minimally invasive advantages; this paper reviews the relevant literature of PubMed database, Wanfang database and CNKI database, in order to provide the treatment basis for clinical application of microwave ablation technology under laparoscopic B-ultrasound in the treatment of CRLM. The results showed that the safety and effectiveness of microwave ablation for liver metastases under the location of B-ultrasonic laparoscopy were confirmed, and patients with liver metastases of colorectal cancer who could not be resected could choose this treatment.

Clinical Efficacy of Stereotactic Radiotherapy and Microwave Ablation for Liver Metastases From Colorectal Cancer.

Clinical Efficacy of Stereotactic Radiotherapy and Microwave Ablation for Liver Metastases From Colorectal Cancer.

Real-Time US-18FDG-PET/CT Image Fusion for Guidance of Thermal Ablation of 18FDG-PET-Positive Liver Metastases: The Added Value of Contrast Enhancement.

To assess the feasibility of US-18FDG-PET/CT fusion-guided microwave ablation of liver metastases either poorly visible or totally undetectable with US, CEUS and CT, but visualized by PET imaging. Twenty-three patients with 58 liver metastases underwent microwave ablation guided by image fusion system that combines US with 18FDG-PET/CT images. In 28/58 tumors, 18FDG-PET/CT with contrast medium (PET/CECT) was used. The registration technical feasibility, registration time, rates of correct targeting, technical success at 24h, final result at 1year and complications were analyzed and compared between the PET/CT and PET/CECT groups. Registration was successfully performed in all cases with a mean time of 7.8 + 1.7min (mean + standard deviation), (4.6 + 1.5min for PET/CECT group versus 10.9 + 1.8min for PET/CT group, P < 0.01). In total, 46/58 (79.3%) tumors were correctly targeted, while 3/28 (10.7%) and 9/30 (30%) were incorrectly targeted in PET/CT and PET/CECT group, respectively (P < 0.05). Complete ablation was obtained at 24h in 70.0% of cases (n = 40 tumors), 23/28 (82.1%) in the PET/CECT group and 17/30 (56.7%) in the PET/CT group (P < 0.037). Fourteen tumors underwent local retreatment (11 ablations, 2 with resection and 1 with stereotactic body radiation therapy), while 4 tumors could not be retreated because of distant disease progression and underwent systemic therapy. Finally, 54/58 (93.1%) tumors were completely treated at 1year. One major complication occurred, a gastrointestinal hemorrhage which required surgical repair. Percutaneous ablation of 18FDG-PET-positive liver metastases using fusion imaging of real-time US and pre-acquired 18FDG-PET/CT images is feasible, safe and effective. Contrast-enhanced PET/CT improves overall ablation accuracy and shortens procedural duration time.

Percutaneous Thermal Ablation with Ultrasound Guidance. Fusion Imaging Guidance to Improve Conspicuity of Liver Metastasis.

To assess whether fusion imaging-guided percutaneous microwave ablation (MWA) can improve visibility and targeting of liver metastasis that were deemed inconspicuous on ultrasound (US). MWA of liver metastasis not judged conspicuous enough on US was performed under CT/US fusion imaging guidance. The conspicuity before and after the fusion imaging was graded on a five-point scale, and significance was assessed by Wilcoxon test. Technical success, procedure time, and procedure-related complications were evaluated. A total of 35 patients with 40 liver metastases (mean size 1.3±0.4cm) were enrolled. Image fusion improved conspicuity sufficiently to allow fusion-targeted MWA in 33 patients. The time required for image fusion processing and tumors' identification averaged 10±2.1min (range 5-14). Initial conspicuity on US by inclusion criteria was 1.2±0.4 (range 0-2), while conspicuity after localization on fusion imaging was 3.5±1 (range 1-5, p<0.001). Technical success rate was 83% (33/40) in intention-to-treat analysis and 100% in analysis of treated tumors. There were no major procedure-related complications. Fusion imaging broadens the scope of US-guided MWA to metastasis lacking adequate conspicuity on conventional US. Fusion imaging is an effective tool to increase the conspicuity of liver metastases that were initially deemed non visualizable on conventional US imaging.

Microwave ablation of liver metastases to overcome the limitations of radiofrequency ablation

The purpose of our study was to evaluate technical success, effectiveness and safety of microwave ablation (MWA) in patients with unresectable liver metastases, where radiofrequency ablation (RFA) presents some limits. Twenty-five patients (17 men, 8 women) with 31 liver metastases >3 cm or located near vessels (>3 mm) were treated in a total of 29 sessions. Tumours were subdivided as follows: colorectal metastases (n=21) and no colorectal metastases (n=10). All procedures were performed percutaneously under ultrasound (US) guidance. Follow-up was performed with computed tomography (CT) scan at 1, 3, 6 and 12 months after treatment; mean follow-up period was 12.04 (range, 3-36) months. Technical success, mean disease-free survival, effectiveness and safety were evaluated. Technical success was obtained in all cases. Mean disease-free survival was of 20.5 months. Local recurrence was recorded in 12.9% of metastases treated (4/31). No major complications were recorded. The rate of minor complications was 44.8% (13/29 sessions). Mortality at 30 days was 0%. Percutaneous MWA of liver metastases >3 cm or located near vessels (>3 mm) can be considered a valid and safe option, probably preferable to RFA. Further studies are required to confirm these encouraging initial results.

CT-guided Percutaneous Microwave Ablation of Liver Metastases from Nasopharyngeal Carcinoma

PurposeTo access efficacy of percutaneous microwave ablation (MWA) of liver metastases from nasopharyngeal carcinoma (NPC). Materials and MethodsFrom March 2007 to June 2012, 18 consecutive patients with NPC and liver metastases (15 men and three women; average age, 45.7 y; age range, 31–61 y) received computed tomography (CT)–guided percutaneous MWA treatment. A total of 27 ablations were performed involving 24 liver metastatic lesions in 18 patients with NPC. Average patient follow-up after ablation was 22.4 months (range, 2–52 mo). The average number of liver metastases per patient was 1.3 (range, 1–4 lesions), with lesion diameters ranging from 1.9 cm to 4.2 cm. Evaluation was then performed to assess percentage of complete necrosis, local tumor progression, and safety. ResultsTechnical success was achieved in all 27 MWA procedures performed. During follow-up, new metastatic lesions developed in four of 18 patients. Of these, two were liver metastases, and were successfully treated with repeat WMA. Only two major complications were observed: pneumothorax in a patient with an ablation pathway involving the thorax and postprocedural pain in two other patients. A median overall survival time of 41.4 months was observed (range, 2–50 mo); three of 18 patients died during follow-up. ConclusionsCT-guided MWA is safe and offers an effective treatment alternative for local tumor control in selected patients with liver metastases from NPC.

Microwave Ablation of Liver Metastases Guided by Contrast-Enhanced Ultrasound: Experience with 125 Metastases in 39 Patients

The aim of our study was to evaluate the efficacy of microwave (MW) ablation of liver metastases guided by B-mode ultrasound (US) and contrast-enhanced US (CEUS). 39 patients (17 women and 22 men) with a total of 125 liver metastases were treated with percutaneous or intraoperative CEUS-guided MW ablation. The primary tumor was colorectal cancer (n = 31), breast cancer (n = 6), carcinoid tumor (n = 1), and gastrointestinal stromal tumor (GIST) (n = 1). The median number of metastases ablated in the 45 treatment sessions was 2 (range 1 - 11). The median size (maximum diameter) of the 125 metastases was 1.5 cm (range, 0.6 - 4.0 cm). Nineteen (15 %) of the 125 metastases were bigger than 2 cm. Metastases smaller than 2 cm were treated with a single needle, metastases bigger than 2 cm were treated with 2 or 3 parallel needles. The 45 MW ablation sessions were performed percutaneously (n = 30), during laparotomy (n = 3), or during laparotomy combined with liver resection (n = 12). The 39 patients were followed up for at least 4 months with a median duration of 11 months (range, 4 - 20 months). The technical success rate was 100 %. The clinical effectiveness was 100 % with complete coverage of the metastasis by the avascular coagulation zone evaluated on immediate post-ablation CEUS. Local tumor progression (local recurrence) was seen in 12 (9.6 %) of the 125 treated metastases, and affected 10 (26 %) of the 39 patients. One major complication was observed in the form of a liver abscess that easily resolved after percutaneous drainage. Four minor complications were observed: Three cases of pain located at the puncture site and one case of ascites. CEUS was valuable in all phases of ablation including pre-ablation staging and procedure planning, placement of MW needles in the tumor, immediate post-ablation control of coagulation size, and finally in the long term follow-up regime. CEUS-guided MW ablation of liver metastases is an efficient and safe ablation technique with several advantages compared to other ablation modalities.

2119: Evaluation of long-term therapeutic effects for ultrasound-guided percutaneous microwave ablation of liver metastases

2119: Evaluation of long-term therapeutic effects for ultrasound-guided percutaneous microwave ablation of liver metastases

Evaluation of long-term therapeutic effects of ultrasound-guided percutaneous microwave ablation of liver metastases

To explore therapeutic results of local microwave ablation for hepatic metastasis and the factors influencing the survival after percutaneous microwave ablation therapy. From July 1995 to June 2005 128 patients with 282 hepatic metastases nodules with the primary diseases of upper gastrointestinal tumor (n = 26), colorectal tumor (n = 44), breast carcinoma (n = 19), pulmonary carcinoma (n = 15), and malignant tumor in other part of the body (n = 24), underwent percutaneous microwave ablation therapy and were followed up for 29.7 +/- 19.9 months (1 - 103 months). The largest diameter of the metastatic nodules was 3.5 +/- 1.6 cm (0.7 - 8.6 cm). Sixty-four cases had 140 nodules <or= 3.0 cm in diameter, and 164 cases had 142 nodules > 3.0 cm in diameter. Forty-seven patients had single nodule, 44 patients had 2 nodules, and 93 patients had 3 or more nodules. Fifty-seven patients had tumor of low differentiation, 53 had tumor of middle differentiation, and 18 had highly differentiated tumors. Kaplan-Meier method was used to calculate the cumulative survival rate. Statistical comparison of the effects of potential predictive factors on survival rate was performed using log-rank analysis. Multivariate analysis of the survival rates was performed by using Cox's proportional hazard model. The 1, 2, 3, 4, and 5-year cumulative survival rates of all 128 patients were 90.88%, 73.84%, 51.09%, 36.14%, and 31.89% respectively. Univariate analysis showed that tumor size (P = 0.028), tumor differentiation (P = 0.026) and local recurrence or new metastases (P < 0.001) significantly affected the survival. Multivariate analysis revealed that tumor size (P = 0.035), recurrence or new metastases (P = 0.001) and tumor differentiation (P = 0.038) each had a significant effect on survival. There is a significantly higher probability of long-term survival for patients with well-differentiated tumors 3.0 cm or less in diameter and without recurrence or new metastasis after percutaneous microwave ablation.