MR-guided laser-induced thermotherapy (LITT) of liver tumours: experimental and clinical data.

MR-guided laser-induced interstitial thermotherapy (LITT) is a percutaneous, minimally invasive treatment modality for treating liver lesions/metastases, soft tissue tumours and musculoskeletal lesions. In this group, MR-guided LITT is currently performed under local anaesthesia on an out-patient basis with a specially designed saline-cooled laser application system. Nd:YAG laser (1064 nm wave length) was used for tumour ablation. Magnetic resonance imaging (MRI) using both open and closed MR units has proven clinically effective in validating the exact positioning of optical fibres. It also allows for real time-monitoring of thermal effects and the evaluation of treatment-induced coagulation necrosis. In liver tumours, percutaneous MR-guided LITT achieves a local tumour control rate of 98.7% at 3 months post-therapy and 97.3% at 6 months with metastases smaller than 5 cm in diameter. The mean survival rate for 1259 patients with 3440 metastases treated with 14 694 laser applications at the institute (calculated with the Kaplan-Meier method) was 4.4 years (95% confidence interval: 4.1-4.8 years) and median survival was 3.00 years. No statistically significant difference in survival rates was observed in patients with liver metastases from colorectal cancer vs metastases from other primary tumours. The rate of clinically relevant side effects and complications requiring secondary treatment was 2.2%. The clinical use of MR guided LITT (size < 5 cm, number < 5) is justified in patients with liver metastases of colorectal and/or breast cancers if the inclusion criteria are carefully observed. Further indications for MR guided LITT include recurrent cancer lesions in the head and neck, lung metastases and bone and soft tissue lesions.     

Magnetic resonance-guided percutaneous microwave coagulation therapy for liver metastases of breast cancer in a case

Real-time magnetic resonance (MR) imaging enables the application of percutaneous microwave coagulation for high-risk patients with metastatic liver tumours. The tumours, local vessels and bile ducts can be observed clearly in three-dimensional sections and a sufficient surgical margin can be confirmed on the MR image even during the coagulation procedure. MR-guided percutaneous microwave coagulation therapy is effective for treatment of not only primary liver tumours but also metastatic breast cancers in the liver, which are not diffuse but discrete, and difficult to treat with only chemo-and endocrine therapy. We report a 44-year-old Japanese woman who underwent modified radical mastectomy for right breast cancer (T1c N0 M0 Stage I). Three years after the operation, she developed two metastatic liver tumours and was treated by MR-guided percutaneous microwave coagulation, achieving a complete response (CR) without any recurrence for 15 months as of the present. The most beneficial aspect of MR-guided percutaneous microwave coagulation is its safety. It is only minimally invasive and can be repeated. This therapy, therefore promises to prolong the disease free period. Additional clinical trials will be valuable to delineate the effectiveness and safety of MR-guided percutaneous microwave coagulation therapy for controlling the liver metastases of breast cancer.     

Ablation therapy of non-colorectal cancer lung metastases: retrospective analysis of tumour response post-laser-induced interstitial thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA)

Purpose: To retrospectively compare the local tumour response and survival rates in patients with non-colorectal cancer lung metastases post-ablation therapy using laser-induced thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA).

Material and methods: Retrospective analysis of 175 computed tomography (CT)-guided ablation sessions performed on 109 patients (43 males and 66 females, mean age: 56.6 years). Seventeen patients with 22 lesions underwent LITT treatment (tumour size: 1.2–4.8?cm), 29 patients with 49 lesions underwent RFA (tumour size: 0.8–4.5?cm) and 63 patients with 104 lesions underwent MWA treatment (tumour size: 0.6–5?cm). CT scans were performed 24-h post-therapy and on follow-up at 3, 6, 12, 18 and 24 months.

Results: The overall-survival rates at 1-, 2-, 3- and 4-year were 93.8, 56.3, 50.0 and 31.3% for patients treated with LITT; 81.5, 50.0, 45.5 and 24.2% for patients treated with RFA and 97.6, 79.9, 62.3 and 45.4% for patients treated with MWA, respectively. The mean survival time was 34.14 months for MWA, 34.79 months for RFA and 35.32 months for LITT. In paired comparison, a significant difference could be detected between MWA versus RFA (p?=?0.032). The progression-free survival showed a median of 23.49?±?0.62 months for MWA,19.88?±?2.17 months for LITT and 16.66?±?0.66 months for RFA (p?=?0.048). The lowest recurrence rate was detected in lesions ablated with MWA (7.7%; 8 of 104 lesions) followed by RFA (20.4%; 10 of 49 lesions) and LITT (27.3%; 6 of 22 lesions) p value of 0.012. Pneumothorax was detected in 22.16% of MWA ablations, 22.73% of LITT ablations and 14.23% of RFA ablations.

Conclusion: LITT, RFA and MWA may provide an effective therapeutic option for non-colorectal cancer lung metastases with an advantage for MWA regarding local tumour control and progression-free survival rate.     

The safety and efficacy of microwave ablation for the treatment of CRC pulmonary metastases

Purpose: Microwave ablation (MWA) is a recently developed thermal ablation technique that has been used for the treatment of different types of tumours. In the present study, we retrospectively evaluated the safety and efficacy of CT-guided percutaneous MWA for the treatment of colorectal cancer (CRC) pulmonary metastases.

Materials and methods: From June 2010 to June 2015, 48 unresectable lesions in 32 patients with CRC pulmonary metastases were subjected to CT-guided MWA. Imaging follow-up was with contrast-enhanced CT and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT.

Results: Oncologic imaging showed that 42 (87.5%) of the 48 lesions in the 32 patients were completely ablated. Needle track metastatic seeding was not found, and no patient deaths occurred within 30?d after ablation. The mean hospital stay was 3?d (range, 2–7?d). Pneumothorax was the most frequent complication and occurred in 6 (12.5%) of the 48 lesions. The median survival time was 31?months (95% CI: 15.4–46.6). The 1-, 2- and 3-year survival rates were 79.5%, 63.1% and 44.4%, respectively. Univariate Cox regression analysis showed that tumour size, disease-free interval (DFI) and number of tumours were significantly related to the overall survival time (p?=?.007, p?=?.022 and p?=?.030, respectively). Multivariate analysis showed that tumour size was an independent prognostic factor for survival (p?=?.017).

Conclusion: CT-guided percutaneous MWA is a safe and effective minimally invasive method for treating CRC pulmonary metastases.     

Repeated transarterial chemoembolisation using different chemotherapeutic drug combinations followed by MR-guided laser-induced thermotherapy in patients with liver metastases of colorectal carcinoma

Background:

To evaluate a treatment protocol with repeated transarterial-chemoembolisation (TACE) downsizing before MR-guided laser-induced interstitial thermotherapy (LITT) using different chemotherapeutic combinations in patients with unresectable colorectal cancer (CRC) liver metastases.

Methods:

Two hundred and twenty-four patients were included in the current study. Transarterial-chemoembolisation (mean 3.4 sessions per patient) was performed as a downsizing treatment to meet the LITT requirements (number⩽5, diameter <5 cm). The intra-arterial protocol consisted of either Irinotecan and Mitomycin (n=77), Gemcitabine and Mitomycin (n=49) or Mitomycin alone (n=98) in addition to Lipiodol and Embocept in all patients. Post TACE, all patients underwent LITT (mean 2.2 sessions per patient).

Results:

Overall, TACE resulted in a mean reduction in diameter of the target lesions of 21.4%. The median time to progression was 8 months, calculated from the start of therapy and the median local tumour control rate was 7.5 months, calculated as of therapy completion. Median survival of patients calculated from the beginning of TACE was 23 months (range 4–110 months), in patients treated with Irinotecan and Mitomycin the median was 22.5 months, Gemcitabine and Mitomycin 23 months and Mitomycin only 24 months with a statistically significant difference between the groups (P<0.01).

Conclusion:

Repeated TACE offers adequate downsizing of CRC liver metastases to allow further treatment with LITT. The combined treatment illustrates substantial survival rates and high local tumour control with statistically significant differences between the three protocols used. Further randomised trials addressing the current study results are required.     

Improving laser-induced thermotherapy of liver metastases--effects of arterial microembolization and complete blood flow occlusion.

INTRODUCTION: A prerequisite for an oncologically curative application of laser-induced thermotherapy (LITT) of liver metastases is complete tumor destruction. This increased effectiveness was achieved experimentally by combining LITT with interrupted hepatic perfusion. The aim of this study was to evaluate whether an interventional selective arterial microembolization might be as effective as complete blood flow occlusion using an open Pringle's maneuver. PATIENTS AND METHODS: We included patients with unresectable colorectal liver metastases. LITT was performed without interrupted hepatic perfusion (control group) compared to LITT in combination with interrupted perfusion either by embolization of intraarterial degradable starch microspheres (DSM) (percutaneous access) or by complete hepatic inflow occlusion (Pringle's maneuver; open access). Online monitoring was performed using intraoperative ultrasound or MRI. Volumetric techniques were used to assess metastases and postinterventional lesions. RESULTS: Fifty-six patients with 104 metastases (control group (25), DSM (37), and Pringle (42)) were treated. The preinterventional tumor volumes were significantly smaller than the postinterventional lesion volumes (control group: 9.8 vs. 25.3 cm3; DSM: 9.5 vs. 65.4 cm3; Pringle: 12.9 vs. 76.5 cm3). The morbidity rate was 21.4% without treatment-related mortalities. After 6 months follow-up, tumor recurrence was diagnosed in 6 patients (control group (4), LITT with DSM (1), and Pringle (1)). CONCLUSIONS: Combining LITT with blood flow occlusion leads to a significant increase in lesion size. The application of DSM offers a safe and effective alternative to the open access with Pringle's maneuver. Compared to LITT-monotherapy, this modality achieves significantly larger thermal lesions with the need of fewer applications.     

Hepatic resection for secondary tumours

The role of liver resection for secondary tumours is reviewed, with particular reference to secondary disease from primary colorectal cancer. While there are no controlled trials producing direct evidence of improved survival following resection, figures on five year survivors without resection are anecdotal. Numerous series now report five year survival of up to 50% following resection, instances of five year survival without resection are now fallen to around 5% in most major series. Factors which adversely affect survival after resection seem to be poor tumour clearance, number of metastases and possibly Dukes' C primary tumours. Other factors, including the extent of resection and size of the tumour, may affect perioperative morbidity and mortality but should not influence long-term survival. Resectional treatment is rapidly gaining an established position in the treatment of colorectal secondaries, and may be considered also for some non-colorectal lesions, particularly endocrine tumours.     

Thymidine phosphorylase and dihydropyrimidine dehydrogenase protein expression in colorectal cancer.

It is essential for actively proliferating cells to increase their rate of DNA synthesis to progress through the cell cycle. This is reflected in the increased uracil usage that is a common feature in solid tumours. Thymidine phosphorylase (TP) anabolises formation of pyrimidine nucleosides available for DNA synthesis, whereas dihydropyrimidine dehydrogenase (DPD) catabolises the degradation of pyrimidine bases, thereby reducing levels of uracil and thymine available for DNA synthesis. In addition, tissue levels of TP or DPD have been associated with the clinical efficacy of pyrimidine anti-metabolites commonly used in the treatment of colorectal cancer. There is little information, however, on the relative expression or degree of co-ordinated regulation of either protein in primary or metastatic colorectal cancer. DPD and TP protein levels were measured in 15 primary colorectal carcinomas, 10 colorectal liver metastases and 25 adjacent uninvolved tissues. DPD was reduced in 67% (10/15) of colorectal tumours (mean tumour/normal = 0.52) and in all liver metastases (mean tumour/normal = 0.41) compared with the corresponding normal tissue. In contrast, TP was increased in 80% (12/15) of colorectal tumours (mean tumour/normal = 18.91) and in all metastases (mean tumour/normal = 3.70). TP and DPD protein expression were highly variable in uninvolved and tumour tissues. The ratio of TP:DPD was higher in 87% of colorectal tumours and in all liver metastases compared with the adjacent uninvolved tissues. This suggests the presence of co-ordinated regulation of these pyrimidine metabolic enzymes and offers a strategy for optimising the use of pyrimidine-based chemotherapy.     

The results of 1115 patients with colorectal cancer treated over an 8-year period in a single hospital

The results of treatment of 1115 patients with colorectal cancer, from one hospital, are presented. The mean age of the patients was 67.24 (+/- 0.35 SEM) years and there were the same number of male and female patients. Forty per cent of patients were admitted as an emergency, and 67% of the tumours were in the rectum or sigmoid colon. 46.7% of the patients were considered to have undergone a 'curative' resection. Six per cent of the tumours were Dukes' Stage A lesions; 37% were Stage B and 57% Stage C. Twenty-six per cent had liver metastases. The overall hospital mortality was 21.5% and the operative mortality 14%. One-third of the patients admitted as an emergency died during their first admission. The overall 5-year survival was 25.8%; those with Dukes' Stage A tumours had a 5-year survival of 82.1%, Stage B 53.6% and Stage C 12.8%. The sex, site of tumour or duration of symptoms had no effect on prognosis.     

Immunoscintigraphy of colorectal cancer using a monoclonal antibody 77-1

The monoclonal antibody (mAb) 77-1 recognizes epithelial membrane antigen (EMA) expressed by the majority of colorectal cancers. Following administration of indium-111 labelled 77-1, gamma camera imaging was carried out on 16 patients with known or suspected colorectal cancer prior to surgery or endoscopic laser therapy. Fourteen of the patients were found to have cancer, with one patient having two primary lesions. Two patients suspected of tumour recurrence were not found to have a lesion at laparotomy. Imaging before operation or laser therapy detected 10 out of 15 lesions (67%). Tumours which produced positive images were found to express the target antigen on immunocytochemical staining of the excised tumours. A mean tumour to normal colon ratio of 1.63 +/- S.D. 0.46 and a mean tumour to blood ratio of 3.60 +/- 1.48 were found at day 6 after antibody administration. A high uptake of radiolabel by the liver prevented the detection of hepatic metastases, present in three patients. Of the two patients with suspected recurrence a false positive scan was found in one owing to the presence of inflammatory tissue. Indium-111 labelled 77-1 may have a role in the imaging or targeting of colorectal cancer.     

CT-guided intratumoural administration of cisplatin/epinephrine gel for treatment of malignant liver tumours

To analyze prospectively the interventional and clinical aspects of computed tomography-guided direct intratumoural injection of a novel chemotherapeutic administration and the parenchymal changes of tumour and necrosis in malignant liver tumours. Eight patients with 17 colorectal liver metastases were treated with a mean of 5.1 injections and nine patients with 13 hepatocellular carcinoma nodules with a mean of 3.1 treatments with computed tomography guided local applications of a novel cisplatin/epinephrine gel. This application provides a higher local and lower systemic drug concentration. Volumes of tumour and necrosis prior and after treatment were measured by computer generated volumetric analysis. Contrast enhanced studies verified pretherapeutic viable tumour volumes with a value of 77.4 ml in the metastases and 29.2 ml in the hepatocellular carcinoma nodules. Intratumoural drug application resulted in a significant increase of necrosis and a decrease in viable tumour volume to be 68.3 ml in metastases and 14.5 ml in hepatocellular carcinoma. Local therapy control rate for the follow up to 6 months was 38 and 71% for the group of metastases and hepatocellular carcinoma, respectively. Direct intratumoural injection of cisplatin/epinephrine injectable gel is a feasible and good tolerated method and results in the development of a statistically significant increase in necrosis in malignant liver tumours. For hepatocellular carcinoma a higher local therapy control rate compared to colorectal metastases can be reported.     

Interventionelle Tumordestruktion durch thermische Verfahren

The aim of this article is to present interventional therapy methods based on thermal ablation, such as radiofrequency ablation (RFA), laser-induced thermotherapy (LITT) and microwave ablation (MWA) for palliative therapy of secondary malignant liver and lung tumors. This report provides information on data about local tumor control rates, survival data, progression-free survival (PFS) and complications. In liver metastases of colorectal carcinoma (CRC) the local tumor control rate is 85% for RFA, 95% for LITT and 93% for MWA, long-time survival is 22 months for RFA, 37 months for LITT and 32 months for MWA, progression-free survival is 84 months for RFA, 97 months for LITT and 93 months for MWA. Recent studies showed improved results with combined systemic and regional chemotherapy (e.g. TACE). Local recurrences of head and neck malignoma, lymph node infiltration and pelvic neoplasia are less frequent indications for tumor ablation.     

MR-guided laser-induced thermo-ablation of liver tumors: clinical experiences and therapy control concepts

Minimally-invasive, laser-induced interstitial thermotherapy (LITT) of solid tumors represents a valid alternative to surgical procedures such as tumor resections. Within the framework of a palliative study on 16 patients, a total of 25 metastases in the liver were treated in an open MR system (0.5 T). The intraoperative scanner design allows patient-based navigation, decisive for a safe applicator positioning, as well as temperature monitoring and direct inspection of the therapy result, without need for patient transfer or repositioning. Although the MR thermometry applied in the open scanner assisted LITT monitoring, the current accuracy of temperature data was not sufficient to serve automatic irradiation control. Therefore, an experimental monitoring and control system was developed in a closed MR scanner (1.5 T) featuring a calibrated MR thermometry. The system provides also an interface to the laser system, allowing the automatic off/on switching of the laser power according to preoperatively defined control criteria. The basic functionality of the automatic laser control was successfully demonstrated with laser ablation experiments of liver samples using irradiation parameters close to typical clinical values.     

Percutaneous thermal ablation for the treatment of colorectal liver metastases and hepatocellular carcinoma: a comparison of local therapeutic efficacy

Aim: This study aimed to compare the local therapeutic efficacy of percutaneous thermal ablation for colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC).

Methods: One hundred sixty-one CRLM nodules in 101 patients and 122 HCC nodules in 97 patients were treated with thermal ablation. Complications and local efficacy were retrospectively compared.

Results: Major complications were observed in two (2.0%) patients in the CRLM group and one (1.0%) in the HCC group (p?=?1.000). The complete ablation (CA) rate of lesions ≤?3?cm was lower in the CRLM group than in the HCC group (p?=?0.018). After a mean follow-up period of 21.1?±?20.7 months in the CRLM group and 22.1?±?17.6 months in the HCC group, the local tumour progression (LTP) rate of lesions >?3?cm was higher in the CRLM group than in the HCC group (p?=?0.036). The multivariate analysis revealed that only safety margin (≤?0.5?cm/>?0.5?cm) was a significant predictor of LTP in both CRLM and HCC.

Conclusions: To achieve better local tumour control, thermal ablation should be more aggressive for CRLM than for HCC, especially for large tumours in clinical.     

Scanning electron microscopy study of the blood supply of human colorectal liver metastases

AIMS: The failure of hepatic artery directed treatment of colorectal liver metastases may reflect a major portal venous contribution to tumour blood supply. This study provides ultrastructural details of the blood supply of colorectal liver metastases and their association with the portal vein and hepatic artery. METHODS: Resected liver specimens from six patients with colorectal liver metastases were examined by histology and scanning electron microscopy (SEM), following vascular resin casting. RESULTS: Nine metastatic colorectal adenocarcinomas were identified. The main feature of all tumours on SEM was direct communication between hepatic sinusoids and tumour vessels. A direct portal venous connection with tumour vessels was observed in a single specimen, whilst a direct arteriole connection was not identified. CONCLUSIONS: It appears that both the hepatic artery and portal vein contribute to the blood supply of colorectal liver metastases through sinusoidal connections with tumour specific blood vessels. SEM provides useful additional information on the morphological features of tumour vasculature.     

Percutaneous radiofrequency ablation for malignant liver tumours in challenging locations

Purpose: To evaluate the treatment results of radiofrequency ablation (RFA) for primary and metastatic malignant liver tumours in challenging locations and also to present the treatment strategy that was used in these cases. Patients and Methods: From January 2007 to January 2010, we performed CT‐guided RFA on 528 lesions in 402 patients (265 men and 137 women; mean age 65.1 years, range 19–82 years) with liver tumours (primary and metastatic) of which 98 lesions in 84 patients (55 men and 29 women; mean age 67.8 years, range 33–82 years) were located in challenging locations, defined as less than 5 mm from a large vessel or an extrahepatic organ (heart, lung, gall bladder, right kidney or gastrointestinal tract). The sizes of the tumours ranged 1.5–6 cm. We used two different RFA systems with an expandable needle electrode (RITA; Rita Medical Systems, Inc, Mountain View, CA, USA and MIRAS; Invatec S.r.l., Roncadelle, Italy).The tumours were considered as ablated completely if no viability was found on dual‐phase dynamic contrast‐enhanced CT at 1 month after RFA. Results: Complete ablation was obtained in 89.7% (88/98) of the high‐risk located lesions, while 10 (10.3%) of the lesions were managed with repeated RFA because of tumour residue. The 1‐, 2‐ and 3‐year survival rates were 82.6, 67.3 and 54.1%, respectively. Minor complications occurred in eight of the 84 patients (9.5%), including small sub‐capsular haematoma in four, small pleural effusion in three and partial liver infarction in one. Local tumour progression rate was 9.2% (9/98). Conclusion: RFA is a safe and effective method of treatment of primary and metastatic liver tumours even located in challenging locations when performed by a well‐trained and experienced interventional radiologist.     

Relevance of Ki-67 antigen expression and K-ras mutation in colorectal liver metastases.

AIMS: The liver is a frequent site of metastases from colorectal cancer. While these lesions are potentially amenable to surgical resection, they are usually very aggressive, and recurrence is frequent. Mutations of the proto-oncogene K- ras are thought to impart a strong growth signal to tumour cells and are closely associated with the development of malignancies of the colon and rectum. Hepatic metastases from colorectal cancer have notably elevated proliferative rates. The present study was performed to investigate the relationship between proliferation or K- ras mutation and prognosis following curative resection of colorectal liver metastases. METHODS: Colorectal liver metastases from 41 patients undergoing curative hepatic resection were examined for proliferation status and presence of K- ras mutations. The proliferative activity was assessed by Ki-67 immunohistochemistry. DNA from the same tissue samples was screened for point mutations in codon 12 of the K- ras gene using a novel microplate-based allelic-specific hybridization assay. Ki-67 scores and K- ras status were then related with patient survival as determined through retrospective analysis. RESULTS: Median survival was 40 months. Patients with high Ki-67 scores (> or = 50%) had significantly shorter median survival compared with those with low scores (30 vs 44 months, log-rank P=0.02). A high Ki-67 score was an independent negative prognostic factor by multivariate regression analysis (relative risk=3.04, P=0.036). K- ras point mutations were detected in 6/41 patients (15%), but mutational status did not correlate with Ki-67 score or survival. CONCLUSIONS: These findings suggest that the tumour proliferative index is a useful predictor of aggressive tumour behaviour and an indicator of patient survival. The presence of K- ras mutations does not appear to correlate with tumour proliferation status or patient survival. Copyright Harcourt Publishers Limited.     

乙型肝炎表面抗原、癌胚抗原与结直肠癌肝转移和预后的关系

目的 探讨HBsAg、CEA与结直肠癌肝转移和预后的关系。方法 回顾性分析2所医院1990年1月－1995年12月间收治的58 结直肠癌的病例资料，并对其HBsAg、CEA进行测定，分别观察它们与肝转移和预后的关系。结果 HBsAg阳性得肝转移率明显低于HBsAg阴性者（P＜0.05）；CEA阳性者与CEA阴性者的肝转移率无显著性差异（P＞0.05），但CEA阳性者的5年生存率（31.3%）明显低于CEA阴性者（84.2%）（P＜0.01）。结论 结直肠癌很少转移至感染乙型肝炎病毒的肝脏，CEA不能作为判断结直肠癌肝转移倾向的指标，但可以作为判断结直肠癌预后的指标之一。     

Human chorionic gonadotropin in colorectal cancer and its relationship to prognosis

The presence of human chorionic gonadotropin in large bowel cancers was studied immunohistochemically using an immunoperoxidase technique. HCG-positive tumour cells were present in 42 of 194 adenocarcinomas examined (22.0% of colon cancer and 21.2% of rectal cancers). On histological grading, the hCG-positive rate tended to rise as the degree of differentiation decreased. HCG was detected more frequently in cancers invading the total bowel wall (27%) than in those invading the partial wall (17.1%). Lymph node, liver or peritoneal metastases were present more frequently in hCG-positive tumours than in hCG-negative tumours. Furthermore, there was an intimate correlation between the presence of hCG-positive tumour cells and CEA doubling times in nine cases with untreated liver metastasis. The survival rate for patients with tissue hCG-positive cells was lower than for those with hCG-negative tumours. Thus, the presence of tissue hCG in colorectal cancers may be a biological marker of prognostic significance.     

Open-configuration MR-guided microwave thermocoagulation therapy for metastatic liver tumors from breast cancer

BACKGROUND: Liver metastases from breast cancer are associated with a poor prognosis, however, local control with microwave thermocoagulation therapy has been used in certain subgroups of these patients in the past decade. In this study, open-configuration magnetic resonance (MR) -guided microwave thermocoagulation therapy was used for metastatic liver tumors from breast cancer, and the efficacy of this treatment was assessed. METHODS: Between June 2000 and April 2004, we used MR-guided microwave thermocoagulation therapy on 11 nodules in 8 patients with metastatic liver tumors from breast cancer. The procedure was carried out under general anesthesia. A 0.5 T open-configuration MR system and a microwave coagulator were used. Near-real-time MR images and real-time temperature images were collected and displayed on the monitor. The MR-compatible thoracoscope was used and combined with MR imaging guidance. Navigation software, a 3D Slicer, was installed and customized. RESULTS: The customized navigation software displayed near-real-time MR images. The percutaneous puncture into the tumors was successful in all cases. No mortality or major complications occurred as a result of the procedures. Five of the 8 patients are alive with new metastatic foci with a mean observation period of 25.9 months. CONCLUSIONS: We developed several devices to allow safe, easy, and accurate MR-guided microwave thermocoagulation therapy of liver tumors. Open-configuration MR-guided microwave thermocoagulation therapy appears to be a feasible method for tumor ablation of metastatic liver tumors from breast cancer.