A Phase II Trial of Image-Guided Radiofrequency Ablation of Small Invasive Breast Carcinomas: Use of Saline-Cooled Tip Electrode

Background Local ablative therapy of breast cancer represents the next frontier in the evolution of minimally-invasive breast conservation therapy. We performed this Phase II trial to determine the efficacy and safety of Radiofrequency (RF) ablation of small invasive breast carcinomas. Methods Seventeen patients with biopsy-proven invasive breast cancer, ≤ 1.5 cm in diameter were enrolled in this trial. Under ultrasound guidance, the tumor and a 5 mm margin of surrounding breast tissue were ablated with saline-cooled RF electrode followed by surgical resection. Pathologic and immunohistochemical stains were performed to assess tumor viability. We examined whether loss of ER, PR receptor and pancytokeratin expression following RF ablation would correlate with non-viability. Results Fifteen patients completed the treatment. The mean tumor size was 1.28 cm. The mean ablation time was 21 minutes using a mean power of 35.5 watts. During ablation, the tumors became progressively echogenic that corresponded with the region of severe electrocautery injury at pathological examination. Of the 15 treated patients, NADPH viability staining was available for 14 patients and in 13 (92.8%), there was no evidence of viable malignant cells. ER, PR expression and pancytokeratin immunohistochemistry analysis were unreliable surrogates for determining non-viability. Following RF ablation, 2 patients developed skin puckering. Conclusions RF ablation is a promising minimally invasive treatment of small breast carcinomas, as it can achieve effective cell killing with a low complication rate. Further research is necessary to optimize this image-guided technique and evaluate its future role as the sole local therapy.     

Radiofrequency ablation of breast cancer: first report of an emerging technology.

HYPOTHESIS: Radiofrequency (RF) energy applied to breast cancers will result in cancer cell death. DESIGN: Prospective nonrandomized interventional trial. SETTING: A university hospital tertiary care center. PATIENTS: Five women with locally advanced invasive breast cancer, aged 38 to 66 years, who were undergoing surgical resection of their tumor. One patient underwent preoperative chemotherapy and radiation therapy, 3 patients received preoperative chemotherapy, and 1 had no preoperative therapy. All patients completed the study. INTERVENTIONS: While patients were under general anesthesia and just before surgical resection, a 15-gauge insulated multiple-needle electrode was inserted into the tumor under sonographic guidance. Radiofrequency energy was applied at a low power by a preset protocol for a period of up to 30 minutes. Only a portion of the tumor was treated to evaluate the zone of RF ablation and the margin between ablated and nonablated tissue. Immediately after RF ablation, the tumor was surgically resected (4 mastectomies, 1 lumpectomy). Pathologic analysis included hematoxylin-eosin staining and enzyme histochemical analysis of cell viability with nicotinamide adenine dinucleotide-diaphorase (NADH-diaphorase) staining of snap-frozen tissue to assess immediate cell death. MAIN OUTCOME MEASURE: Cancer cell death as visualized on hematoxylin-eosin-stained paraffin section and NADH-diaphorase cell viability stains. RESULTS: There was evidence of cell death in all patients. Hematoxylin-eosin staining showed complete cell death in 2 patients. In 3 patients there was a heterogeneous pattern of necrotic and normal-appearing cells within the ablated tissue. The ablated zone extended around the RF electrode for a diameter of 0.8 to 1.8 cm. NADH-diaphorase cell viability stains of the ablated tissue showed complete cell death in 4 patients. The fifth patient had a single focus of viable cells (<1 mm) partially lining a cyst. There were no perioperative complications related to RF ablation. CONCLUSIONS: Intraoperative RF ablation results in invasive breast cancer cell death. Based on this initial report of the use of RF ablation in breast cancer, this technique merits further investigation as a percutaneous minimally invasive modality for the local treatment of breast cancer.     

Radiofrequency Ablation of Invasive Breast Carcinomas: A Phase II Trial

Background Local ablative therapy of breast cancer represents the next frontier in the minimally invasive breast-conservation treatment. We conducted a phase II trial to evaluate radiofrequency ablation (RFA) of invasive breast carcinomas. Methods Consecutive patients from two Mexican Institutions with invasive breast cancers < 4 cm, with no multicentric tumors and no previous chemotherapy were included in this trial. Under ultrasound guidance, the tumor and a 5 mm margin of surrounding breast tissue were ablated with saline-cooled RFA electrode followed by surgical resection. Routine pathologic analysis and viability evaluation with NADPH-diaphorase stain were performed to assess tumor ablation. Procedure-associated morbidity was recorded. Results Twenty-five patients were included. Mean patient age was 55.3 years (range 42–89 years). Mean tumor size was 2.08 cm (range 0.9–3.8 cm). Fourteen tumors (56%) were <2 cm. The mean ablation time was 11 minutes using a mean power of 35 W. During ablation, the tumors become progressively echogenic that corresponded with the region of severe RFA injury at pathologic examination. Of the 25 patients treated, NADPH stain showed no evidence of viable malignant cells in 19 patients (76%), with significant difference between tumors <2 cm (complete necrosis in 13 of 14 cases, 92.8%) vs. those >2 cm (complete necrosis 6 of 11 cases, 54.5%) (P < .05). No significant morbidity was recorded. Conclusions RFA is a promising minimally invasive treatment of small breast carcinomas, as it can achieve effective cell killing with a low complication rate. Further studies are necessary to optimize the technique and evaluate its future role as local therapy for breast cancer.     

Minimally-invasive treatment of early stage breast cancer: A feasibility study using radiofrequency ablation under local anesthesia

The objective of this study was to assess efficacy and safety of percutaneous ultrasound (US) guided preferential radiofrequency ablation (PRFA) in early breast carcinoma under local anesthesia and to evaluate a new assessment protocol. Eighteen breast cancer patients were enrolled in order to receive PRFA treatment three weeks prior to resection. Pain assessment was performed using the visual analoge scale. Analysis of treatment success was performed using magnetic resonance imaging (MRI) as well as histological assays for hematoxylin & eosin (H&E) and cytokeratine 8 (CK8). In a subset of patients contrast enhanced ultrasound (CEUS) was performed before and after treatment. MRI showed no residual tumor growth in 100% (18/18) of cases. Complete tumor devitalization was indicated in 83% (15/18) of patients as judged by H&E staining and in 89% (16/18) as judged by immunostaining for CK8. In 100% (18/18) at least one histologic method showed devitalization in the entire tumor. Treatment was well tolerated. Pain experienced during the procedure was mild. US-guided PRFA of small breast carcinoma is feasible under local anesthesia. MRI and CK8 have proven valuable additions to the RF breast tumor ablation protocol. CEUS shows potential as a modality for radiological follow-up.     

腔镜保乳手术联合射频消融术治疗早期乳腺癌的临床研究

目的 探索腔镜保乳手术联合射频消融术治疗早期乳腺癌的可行性及疗效分析.方法 回顾性分析2014年1月-2016年12月首都医科大学附属北京友谊医院普通外科行腔镜保乳手术的55例早期乳腺癌女性患者的病例资料,其中27例行腔镜保乳手术联合射频消融术,28例行单纯腔镜保乳手术而未行射频消融术,并通过t检验及x2检验的统计学方法来明确两组之间的差异是否存在统计学意义.本临床研究主要评价指标为术后局部复发情况、脂肪液化的发病率、手术时间、术后住院时间、住院费用.结果 腔镜保乳手术联合射频消融术组局部复发率低于未行射频消融术组(分别为0和7.69％).同时,在脂肪液化这一可能影响术后康复的并发症方面,两组之间差异无统计学意义(P =0.236).但是,腔镜保乳手术联合射频消融术组较未行射频消融术组住院费用高[分别为(4.1±0.7)万元和(2.3±0.6)万元,P＜0.05].结论 采用腔镜保乳手术联合射频消融术治疗早期乳腺癌,虽然因使用射频消融术相关设备和器械会导致住院费用增加,但此手术方式不仅具备清除乳腺残腔中微小癌残留的优点,而且在减少术后肿瘤复发率的同时不增加术后脂肪液化的发病率.因此,此手术方式将会成为乳腺癌微创手术治疗的重要发展方向之一.     

Feasibility study on the treatment of small breast carcinoma using percutaneous US-guided preferential radiofrequency ablation (PRFA)

The purpose of this study was to determine the safety and efficacy of percutaneous ultrasound (US) guided preferential radiofrequency ablation (PRFA) of unifocal human invasive breast carcinoma with largest radiological diameters of up to 16 mm. Thirty-three patients were enrolled in a study to be treated prior to scheduled partial mastectomy. A needle-shaped treatment electrode, successively developed in two different sizes, was placed into the center of the lesions using ultrasound guidance. A temperature of 85 °C was maintained for 10 min. The analysis of the resected specimen was performed using conventional histopathological methods with the aim to determine the size of the lesion as well as the potential viability of tumor cells. Of the 33 patients enrolled 31 were treated. In 26 (84%) patients a complete ablation of the tumor was achieved. Ultrasound guided preferential radiofrequency ablation of small breast carcinoma is feasible and patient friendly. The success rate depends on accurate preoperative diagnostic imaging as well as an exact position of the needle electrode.     

Can we change the operative criteria for the MAZE procedure combined with valve surgery in the era of radiofrequency devices?

Purpose  

After radiofrequency (RF) ablation became available, the indication of MAZE procedure conducted with bipolar RF was expanded. We examined the efficacy and feasibility of the RF MAZE procedure in valve surgery and identified the predictors of atrial fibrillation (AF) recurrence.     

Radiofrequency Ablation of Metastases from Renal Cell Carcinoma: Technique,Complications, and Midterm Outcome

ObjectivesTo determine the therapeutic effect of radiofrequency ablation of metastases from renal cell carcinoma (RCC) with respect to complications and local tumor control.MethodsSixty-six radiofrequency ablations under computed tomography (CT) fluoroscopy control were performed in 38 patients with metastatic RCC. The ablation was performed for local tumor volume reduction in 7 patients and for complete local tumor control in 31 patients. Sites of ablation included the liver (39), lung (11), kidney (11), adrenal glands (2), and lymph nodes or soft tissue (3). CT scanning was performed immediately after the ablation procedure and at 3, 6, 12,18, and 24 mo during the follow-up period. Size of the target lesion, ablation duration and temperature, and complications associated with the ablation procedure and rate of local recurrence were recorded.ResultsAt a mean follow-up of 10 mo (median: 12 mo; range: 3–47 mo), no complications were observed except two pneumothoraces that did not require further intervention. The average metastasis size was 7.9 cm in patients treated for volume reduction and 2.3 cm in patients treated for local tumor control. One local recurrence in the kidney, caused by incorrect needle placement during the ablation procedure, was detected on the first imaging control. The average ablation duration per metastasis was 11.5 min; a mean temperature of 70.5 °C was reached in the target lesion.ConclusionsPercutaneous radiofrequency ablation represents a safe treatment technique for metastases from RCC. Indications in selected patients may be both tumor volume reduction and complete ablation of the metastatic site.     

Radiofrequency ablation lesions in a pig liver model.

BACKGROUND: Radiofrequency (RF) ablation has been reported as a means of liver tumor destruction. This study evaluates the use of ultrasound monitoring of radiofrequency lesion creation and describes the morphology, histologic characteristics, and vascular effects of radiofrequency ablations in a pig liver model. MATERIALS AND METHODS: Hemodynamic monitoring was established and laparotomies were performed in 50-kg pigs. Under ultrasound guidance, radiofrequency needle probes were placed in the liver at predetermined locations. Radiofrequency energy was applied over 15 min to generate lesions 3 cm in diameter. Eighty lesions were generated in 10 animals. At the completion of the experiment, the lesions were examined with ultrasound and then excised for CT, gross, and histologic examination. RESULTS: There were no adverse systemic effects. Ultrasound imaging demonstrated the size, shape, and position of the lesions. Gross examination demonstrated a core of ablated tissue with a surrounding 1- to 2-mm hemorrhagic perimeter. Lesion volumes averaged 12.8 cc(3) (range 5-34 cc(3)). Final lesion shape and size were frequently altered by the cooling effect of local blood flow. Histologic stains demonstrated microvascular thrombosis and coagulative necrosis within the lesions. There appeared to be 100% cellular destruction within the lesion by cytochemical staining. CONCLUSIONS: We demonstrated that RF ablation is capable of killing large volumes of normal liver tissue; however, local vasculature plays a significant a role in defining the ultimate size and shape of the lesion created. This may interfere with the utility of radiofrequency ablation as a modality for local tumor control.     

Cryoablation of Early-Stage Breast Cancer: Work-in-Progress Report of a Multi-Institutional Trial

Background With recent improvements in breast imaging, our ability to identify small breast tumors has markedly improved, prompting significant interest in the use of ablation without surgical excision to treat early-stage breast cancer. We conducted a multi-institutional pilot safety study of cryoablation in the treatment of primary breast carcinomas.Methods Twenty-nine patients with ultrasound-visible primary invasive breast cancer 2.0 cm were enrolled. Twenty-seven (93%) successfully underwent ultrasound-guided cryoablation with a tabletop argon gas-based cryoablation system with a double freeze/thaw cycle. Standard surgical resection was performed 1 to 4 weeks after cryoablation. Patients were monitored for complications, and pathology data were used to assess efficacy.Results Cryoablation was successfully performed in an office-based setting with only local anesthesia. There were no complications to the procedure or postprocedural pain requiring narcotic pain medications. Cryoablation successfully destroyed 100% of cancers <1.0 cm. For tumors between 1.0 and 1.5 cm, this success rate was achieved only in patients with invasive ductal carcinoma without a significant ductal carcinoma-in-situ (DCIS) component. For unselected tumors >1.5 cm, cryoablation was not reliable with this technique. Patients with noncalcified DCIS were the cause of most cryoablation failures.Conclusions Cryoablation is a safe and well-tolerated office-based procedure for the ablation of early-stage breast cancer. At this time, cryoablation should be limited to patients with invasive ductal carcinoma 1.5 cm and with <25% DCIS in the core biopsy. A multicenter phase II clinical trial is planned.     

eRFA: Excision Followed by RFA—a New Technique to Improve Local Control in Breast Cancer

Introduction Excision followed by RFA (eRFA) may allow improved cosmesis while ensuring negative margins in patients with breast cancer. This technique utilizes heat to create an additional tumor-free zone around the lumpectomy cavity. We hypothesized that eRFA will decrease the need for re-excision of inadequate margins.Methods Between July 2002 and January 2005, we conducted a multiphase trial of RFA of prophylactic mastectomy specimens and of women desiring lumpectomy. In both models, a lumpectomy was performed, the RFA probe was deployed 1 cm circumferentially into the walls of the lumpectomy cavity and maintained at 100°C for 15 min. Whole mount slides were used to measure the zone of ablation for ex vivo specimens. Hematoxylin and eosin staining of in vivo lumpectomy margins <3 mm was considered inadequate.Results Nineteen prophylactic mastectomy ablations revealed a consistent perimeter of ablation. Forty-one patients (mean age 63 ± 14 years) had an average tumor size of 1.6 ± 1.5 cm underwent in vivo eRFA, and 25% had inadequate margins: one focally positive, one <2 mm, eight <1 mm and one grossly positive. Only the grossly positive margin was re-excised. Overall complication rate of in vivo ablations was 7.5%. Twenty-four of 41 patients did not have post-eRFA XRT. No in-site local recurrences have occurred during a median follow-up of 24 months (12–45 months). Two patients have occurred elsewhere.Conclusions The ex vivo ablation model reliably created a 5–10 mm perimeter of ablation. In vivo, this zone reduced the need for re-excision for inadequate margins by 91% (10/11). Short-term follow-up suggests that eRFA could reduce re-excision surgery and local recurrence.     

早期乳腺癌射频消融术后疗效的评估方式及进展

随着乳房体检的推广和医学技术的提高,越来越多的早期乳腺癌患者得到确诊。传统的乳腺癌手术创伤大、并发症多,并且术后遗留较长瘢痕影响乳房美观。近年来乳腺癌微创手术逐步应用于临床,给早期乳腺癌患者带来了美学上的期望,射频消融正是其中一种被广泛应用的技术。本文对评估乳腺肿瘤是否完全消融的方式进行探讨和总结,探讨评估方式的发展前景。     

Intraoperative Radiofrequency Ablation for Hepatocellular Carcinoma: Long-Term Results in a Large Series

Background  Intraoperative radiofrequency (RF) ablation with or without surgical resection currently plays one of important roles in modern hepatocellular carcinoma (HCC) therapy. We evaluated long-term follow-up results including prognostic factors of intraoperative RF ablation for HCC that was difficult to treat percutaneously. Methods  A total of 133 patients (male, 22 female, mean age 55.8 years) underwent intraoperative RF ablations for 200 HCCs (follow-up period 3.0–79.7 months, median 22.3 months). Hepatic resection was also performed in 29 patients. Reasons for the intraoperative procedure included no safe electrode path (n = 59), excessive tumor burden (n = 41), nonvisualization of the HCC on ultrasonography (n = 20), and risk of collateral thermal damage to adjacent organs (n = 13). We evaluated the technique effectiveness rate at 1 month computed tomography (CT), cumulative local tumor progression rate, cumulative disease-free and overall survival rates, and complications. We also sought significant prognostic factors for overall survival. Results  The technique effectiveness at 1 month was 94.7% (126/133). The cumulative local tumor progression rates at 1 and 3 years were 4.9% and 8.8%, respectively. The cumulative disease-free and overall survival rates at 1, 3 and 5 years were 51.8%, 21.3%, and 16.0% and 92.3%, 72.6%, and 46.5%, respectively. Major complications occurred in nine patients (6.8%). Procedure-related mortality was 1.5% (2/133). The patients treated for recurrent HCC (P = 0.003) or with high serum alpha-fetoprotein levels (P = 0.009) had poor survival by multivariate analysis. Conclusion  The results of this study showed that intraoperative radiofrequency ablation with or without hepatic resection is a safe and effective treatment for hepatocellular carcinoma in patients who are not candidates for the percutaneous approach.     

Ablación por radiofrecuencia del lecho quirúrgico tras tumorectomía en cirugía conservadora del cáncer de mama

IntroductionObtaining tumor-free margins during breast conservative surgery (BCS) is essential to avoid local recurrence and frequently requires reoperation. Radiofrequency ablation (RFA) of surgical margins after lumpectomy seems to be a helpful tool to avoid reoperations, but evidence is insufficient. This study analyzes the efficacy and safety of RFA after BCS to obtain free surgical margins.MethodsNon-randomized experimental study performed in an intervention group of 40 patients assigned to receive RFA after lumpectomy and successive resection of surgical margins, and a historical control group of 40 patients treated with BCS alone. In the intervention group, the RFA effect on tumor cell viability in the surgical margins was analyzed. Also, reoperation rate, complications and cosmetic results were compared in both groups.ResultsA total of 240 excised margins were analyzed after RFA, obtaining a high number of tumor-free margins. Compared to the control group, the reoperation rate decreased significantly (0% vs 12%; P = .02), without differences in terms of postoperative complications (10% vs 5%; P = .67) or cosmetic results (excellent or good 92.5% vs 95%; P = .3).ConclusionsRFA after lumpectomy is a reliable, safe and successful procedure to obtain tumor-free surgical margins and to decrease the reoperation rate without affecting complications or compromising cosmetic results.     

射频消融治疗复发性肝细胞癌疗效分析

目的探讨射频消融对肝细胞癌(HCC)手术切除后复发病例再治疗的效果,比较不同复发时间的疗效差别。方法以行超声引导经皮射频消融(RFA)治疗的手术切除后复发性肝细胞癌(RHCC)患者(RHCC组)和同期行RFA治疗的首发HCC患者(首发HCC组)为研究对象。(1)RHCC组42例患者,男34例,女8例,平均年龄(58±10)岁;复发灶大小1.5~6.6cm,平均(3.8±1.4)cm。RFA治疗前5例伴肝外转移。肝功能A级21例,B级19例,C级2例。手术切除距肝内初次复发时间为1~96个月,平均22.8个月。术后1年内肿瘤复发者20例40灶(RHCC近期组),术后1年以上复发者22例37灶(RHCC远期组)。(2)首发HCC组148例患者,男117例,女31例,平均年龄59岁。肿瘤大小1.2~7.0cm,平均(4.0±1.4)cm。RFA治疗后1个月采用增强CT检查评价消融成功率;比较RHCC近期组、RHCC远期组和首发HCC组的治疗效果、复发转移情况及生存期。结果首发HCC组RFA成功率为87.2%(129例),局部复发率为16.2%(24例),另位复发率为37.8%(56例),平均生存期为(39.0±2.1)个月;RHCC近期组、远期组RFA成功率分别为85.0%和95.5%(P>0.05),局部复发率分别为15.0%和13.6%(P>0.05),另位复发率为60.0%和18·2%(P=0.005),平均生存期为(15.4±2.3)个月和(39.5±4.5)个月(P<0.005)。与首发HCC组相比,RHCC远期组消融成功率与局部复发率均无显著性差异(P>0.05),RHCC近期组生存期低于首发HCC组(P<0.05)。RHCC远期组1例患者治疗后出血,经射频止血、输血等保守治疗缓解。结论RFA治疗RHCC的预后及疗效与复发的时间相关;对于术后远期复发者,行RFA治疗可获得同首发HCC相似的生存期,而手术后近期复发者疗效相对较差。     

Survival Analysis of Re-resection Versus Radiofrequency Ablation for Intrahepatic Recurrence After Hepatectomy for Hepatocellular Carcinoma

Background  

Tumor recurrence after resection of hepatocellular carcinoma is a common phenomenon. Re-resection and radiofrequency ablation (RFA) are good options for treating recurrent HCC. This study compared the efficacy of these two modalities in the treatment of intrahepatic HCC recurrence after hepatectomy.     

Feasibility study on radiofrequency ablation followed by partial mastectomy for stage I breast cancer patients

To evaluate the safety and reliability of thermal ablation therapy instead of breast-conserving surgery (BCS), we performed radiofrequency ablation (RFA) for clinical stage I breast cancer patients. Subjects were T1N0 breast cancer patients with no extensive intraductal components. Under general anesthesia, sentinel node biopsy was performed, followed by RFA and BCS. Resected specimens were examined at 5-mm intervals by hematoxylin–eosin (H&E) staining and nicotinamide adenine dinucleotide (NADH) diaphorase staining. Thirty of the 34 eligible patients were enrolled. RFA-related adverse events were observed in nine patients: two with skin burn and seven with muscle burn. Twenty-six patients (87%) showed pathological degenerative changes in tumor specimens with H&E staining. In 24 of the 26 cases (92%) examined by NADH diaphorase staining, tumor cell viability was diagnosed as negative. RFA proved to be reliable and feasible in clinical stage I breast cancer, with no extensive intraductal components. Randomized clinical trials are needed to compare RFA with BCS.     

Phase II trial of radio frequency ablation of renal cancer: evaluation of the kill zone

PURPOSE: We report on the pathological evaluation of renal tumors after intraoperative radio frequency ablation performed immediately before surgical nephrectomy. MATERIALS AND METHODS: Ten patients with renal tumors were enrolled in a prospective, Institutional Review Board approved phase II trial of radio frequency ablation. Following surgical exposure of the kidney a single 12-minute radio frequency ablation of the tumor was performed using the Radionics Cool-tip RF Radio Frequency Ablation System (Radionics, Burlington, Massachusetts). The tumor was then excised via radical or partial nephrectomy. Gross and histological evaluations of the tumor were performed, including evaluation with nicotinamide adenine dinucleotide vital staining. RESULTS: All 10 tumors were confirmed histologically to be renal cell carcinoma. Mean tumor size was 3.2 cm. (range 1.4 to 8.0). Of the 10 tumors 8 were completely ablated with a mean treatment margin of 6.75 mm. (range 2 to 13). Of the 2 tumors that were incompletely treated 1 never attained a temperature sufficient for tissue destruction and the other measured 8 cm., far exceeding the expected ablation volume of treatment protocol. CONCLUSIONS: This study represents the initial report of the histological outcome of saline cooled radio frequency ablation of renal tumors. Our data indicate that it can completely destroy renal cancers while transmitting minimal collateral damage to surrounding renal parenchyma. Further investigation is required to determine long-term oncological outcome.     

Radiofrequency ablation in patients with primary and secondary hepatic malignancies

The aims of this study were to assess the technical effectiveness of radiofrequency (RF) ablation in patients with primary or secondary hepatic malignancies and to determine survival and complication rates. This was a retrospective analysis of prospectively collected data of patients treated with RF ablation and controlled for recurrence every 3 months by contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI). The outcome is compared with a comprehensive review of data published in recent literature. Forty-seven patients underwent 50 RF sessions for the ablation of 73 tumors. Local tumor progression was observed in 11 patients (23%). A tumor sized larger than 30 mm, a tumor load larger than 14 cm³, and a percutaneous approach were associated with a faster time to local tumor progression. At the end of a mean (±SD) follow-up period of 11.4±7.5 months, 39 patients (83%) were alive, including eight patients with recurrent disease. The overall cumulative survival rates at 12 and 24 months were 87% and 70%, respectively. In our center, RF ablation can be safely performed to achieve adequate local control and survival rates. Time to local tumor progression was significantly related to initial size of the tumor and tumor load. Presented at the biannual meeting of the Dutch Society for Surgery, Ede, The Netherlands, November 25, 2005 (oral presentation).     

Pathologic Correlation Study of Microwave Coagulation Therapy for Hepatic Malignancies Using a Three-Ring Probe

Microwave coagulation therapy (MCT) for the ablation of unresectable hepatic malignancies is a promising alternative to radiofrequency and cryoablation techniques. There are few data on the clinical effectiveness of MCT. In vivo pathologic evaluation of ablated tumor tissue is not well described for the three-ring microwave probe. The study design was a prospective trial enrolling patients with resectable hepatic malignancies. Lesions underwent in vivo MCT with the three-ring probe prior to liver resection. Gross and histologic evaluations of the tumor were performed, including nicotinamide adenine dinucleotide (NADH) vital staining. A total of nine patients with metastatic colon cancer were enrolled and had NADH stains performed of their pathologic specimens. The median size of the metastasis being ablated was 3.5 cm (range, 1.5–12.3). Fifty-six percent of the tumors demonstrated evidence of spontaneous coagulative necrosis on immediate histologic examination. The median dimensions of the ablation zones were 5 cm (range, 3–7) × 4.5 cm (range, 2.5–5.2) × 4.2 cm (range, 2–5) with a 5-min ablation at 60 W. The median ablation volume was 50.6 cm³ (range, 9–78). NADH vital staining was performed of the ablation zones with 100% absence of staining in the tumor tissue and in benign hepatic parenchyma, which is consistent with irreversible cellular damage. In conclusion, in vivo MCT of hepatic malignancies with the three-ring probe produces nonviable tumor cells after a 5-min ablation. The ablation time is significantly shorter than other available ablative techniques. Immediate histologic exam produces some evidence of coagulative necrosis. Further study of this promising technology is warranted. Poster presentation at the Society of Surgical Oncology annual meeting, March 24, 2006, San Diego, CA.