Minimally invasive nephron-sparing surgery (MINSS) for renal tumours. Part II: probe ablative therapy

OBJECTIVES: To review the evolution and current status of probe ablative methods of minimally invasive nephron-sparing surgery (MINSS) for renal tumours. METHODS: The English language literature of the past 10 yr was reviewed by using the National Library of Medicine database and the following keywords: chemoablation, cryoablation, high-intensity focused ultrasound, kidney, laser interstitial thermotherapy, microwave thermotherapy, nephron-sparing surgery, radiofrequency ablation, radiosurgery, renal, and tumour. Over 300 papers were identified, 50 of which were selected for this review on the basis of their contribution in advancing the field with regards to (1) evolution of concepts, (2) development and refinement of techniques, and (3) intermediate- and long-term clinical outcomes. RESULTS: Open partial nephrectomy is the reference standard for nephron-sparing surgery against which all MINSS techniques should be measured. Although the initial outcomes of cryoablation and radiofrequency ablation (RFA) are encouraging, long-term studies are necessary to confirm lasting efficacy. The optimal modality for tumour targeting, monitoring therapy, and follow-up remains to be determined. These ablative techniques should be reserved for carefully selected patients, the data should be prospectively accrued, and the long-term cancer cure rates should be compared with the reference standard. CONCLUSIONS: Promising long-term data are available for cryoablation. RFA is still considered developmental, and instances of incomplete cell kill, despite nonenhancement, are concerning. Other modalities are still experimental.     

Interstitial ablative techniques for hepatic tumours

BACKGROUND: Most patients with liver tumours are not suitable for surgery but interstitial ablative techniques may control disease progression and improve survival rates. METHODS: A review was undertaken using Medline of all reported studies of cryoablation, radiofrequency ablation, microwave ablation, interstitial laser photocoagulation, high-intensity focused ultrasound and ethanol ablation of primary liver tumours and hepatic metastases. RESULTS: Although there are no randomized clinical trials, cryoablation, thermal ablation and ethanol ablation have all been shown to be associated with improved palliation in patients with primary and secondary liver cancer. The techniques can be undertaken safely with minimal morbidity and mortality. CONCLUSION: Although surgical resection remains the first line of treatment for selected patients with primary and secondary liver malignancies, interstitial ablative techniques are promising therapies for patients not suitable for hepatic resection or as an adjunct to liver surgery.     

Energy ablative techniques for treatment of small renal tumors

PURPOSE OF REVIEW: The success of partial nephrectomy for the treatment of small renal cancers has led to the development of energy ablative technologies, which are less invasive alternatives for performing nephron-sparing surgery. Currently, cryoablation and radiofrequency ablation are the two most reported technologies. Both technologies use very different means to cause cellular injury. Additionally, three newer technologies, high-frequency ultrasound ablation, laser interstitial therapy, and microwave therapy are emerging in the literature. RECENT FINDINGS: Three- and 4-year data for cryoablation and radiofrequency ablation are now becoming available. On the basis of these studies, it is clear that ablative technologies can be effective treatments for select small renal tumors. It is also evident that both percutaneous and laparoscopic approaches offer minimal morbidity. SUMMARY: As long-term (5 years and greater) outcome data for ablative technologies accumulate, we are likely to see an increase in clinical reports, including more patients who may be candidates for extirpative surgery. Technology will advance, leading to smaller probes with larger treatment zones, making it possible to treat larger tumors and potentially even tumors in the advanced disease state.     

Imaging technologies in breast diagnosis and surgical treatment

The diagnostic and surgical management of breast cancer has changed dramatically over the past 2 decades. All facets in the multidisciplinary management of breast cancer are rapidly evolving and being driven forward by technological advances. Conventional imaging techniques are now being augmented with advances in molecular imaging that probe biological properties of tissue to create images, and optical imaging which reflects physical properties of normal and diseased tissues. Automated computer assisted biopsy techniques are being developed to sample breast tissue with a higher degree of accuracy and patient comfort. As the trend toward minimally invasive breast surgery continues ablative techniques such as radiofrequency ablation, cryoablation, interstitial laser ablation and focused ultrasound ablation are being explored to potentially avoid the need for surgery all together. New intraoperative lesion localization techniques such as 3-dimensional ultrasonographic tumor models, magnetic resonance imaging (MRI)-guided projection and reproduction, radioguided occult lesion localization and optical imaging techniques are being developed to improve surgical guidance. Evaluation of advanced imaging and intraoperative guidance techniques requires more comprehensive histopathological examination of surgical specimens, prompting the development of techniques aimed at to improving upon the current limitations in breast pathology. This review will describe the development of new technologies in breast imaging, tumor ablation, intraoperative surgical guidance and tissue processing aimed at advancing minimally invasive diagnosis and treatment of breast cancer.     

Other Thermal Ablation Techniques: Microwave and Interstitial Laser Ablation of Liver Tumors

Background: Thermal ablation of hepatic malignancies is becoming a widespread treatment approach. In addition to radiofrequency ablation, microwave coagulation (MCT) and laser-induced interstitial thermotherapy (LITT) are being used clinically to treat patients with liver cancers.Methods: The principles and clinical indications for MCT and LITT are described. Treatment approaches and results from published clinical studies are reviewed. The evolution of these thermal treatment modalities and limitations of currently available equipment is provided.Results: The interstitial probes and equipment used for MCT and LITT for liver tumors are undergoing changes to improve treatment efficacy. Both MCT and LITT have been limited by the relatively small zone of coagulation produced with a single probe placement. Both techniques can be performed safely, and local recurrence and long-term survival rates are being established.Conclusions: MCT and LITT are two alternative thermal ablation techniques being used to treat patients with primary and metastatic hepatic malignancies. The utility of these two treatments has been limited by the relatively small area of thermal necrosis produced around the interstitial probes, but design modifications and new equipment may improve these limitations.     

Target ablation—Image-guided therapy in prostate cancer

IntroductionCurrent treatment options for prostate cancer, other than active surveillance, are limited to entire prostate gland destruction through removal (radical prostatectomy), radiation (external beam, brachytherapy, or a combination of both), or thermal ablation (cryoablation, high-intensity focused ultrasound, or radiofrequency). There has been a demand to develop ablative therapies that attempt to reduce treatment burden while retaining cancer control and avoiding the psychological morbidity associated with surveillance.Materials and methodsWe reviewed the literature to concentrate on the practical aspects of focal therapy for Pca with the following key words: photodynamic therapy, HIFU, cryotherapy, focal laser ablation, electroporation, radiofrequency, external beam radiation, organ-sparing approach, focal therapy, prostate cancer. The aim of this article is to review these energy modalities' functional and oncologic results.ResultsProstatic tumor ablation can be achieved with different energies: freezing effect for cryotherapy, thermal effect using focalized ultrasound for HIFU and using thermal effect of light for FLA and activation of a photosensitizer by light for PDT, among others. Radiofrequency and microwave therapy have been tested in this field and demonstrated their usefulness. Electroporation is currently being developed on preclinical models. External beam radiation with microboost on neoplastic foci is under evaluation. HIFU and cryotherapy require the use of sophisticated and expensive machines. However, series published short term effective with low morbity, reversible therapy.ConclusionSeveral energy modalities are being developed to achieve the trifecta of continence, potency, and oncologic efficiency. Comparison of the different focal approaches is complex owing to important heterogeneity of the trials. In the future, it seems likely that each technique will have its own selective indications.     

Nonablative minimally invasive thermal therapies in the treatment of symptomatic benign prostatic hyperplasia

PURPOSE OF REVIEW: As all new treatment modalities nonablative thermal therapy for minimal invasive treatment of benign prostatic hyperplasia should be critically analyzed. This review discusses the literature to identify the merits of these so-called minimally invasive treatments and the place they should take in the armamentarium of benign prostatic hyperplasia therapy options. RECENT FINDINGS: In this review we analyze the different techniques and clinical studies of hot water induced thermotherapy, transurethral microwave thermotherapy, transurethral needle ablation and high intensity focused ultrasound. The high intensity focused ultrasound treatment is noninvasive, but due to the poor clinical results in benign prostatic hyperplasia and its need for anesthesia, this therapeutic option shifted towards the selective ablation of prostate cancer. The transurethral needle ablation treatment can be performed in an outpatient setting although most centers do not. The treatment is not suitable for the bigger prostates and therefore narrows its indication. Water induced thermotherapy is a very promising therapy, although without comparative studies a justified positioning remains difficult. SUMMARY: Of all nonablative thermal therapies, transurethral microwave thermotherapy is the best documented and with several randomized studies comparing transurethral microwave thermotherapy to surgical treatments of the prostate, this therapy definitively found its place as a serious alternative to the ablative surgical treatment options.     

Third Prize: Comparison of radical nephrectomy, laparoscopic microwave thermotherapy, cryotherapy, and radiofrequency ablation for destruction of experimental VX-2 renal tumors in rabbits

BACKGROUND AND PURPOSE: Currently available minimally invasive renal tumor-ablation procedures include cryotherapy, radiofrequency ablation, and microwave thermotherapy. In this study, we investigated the ability of these three approaches to destroy experimental renal tumors in rabbits. The mechanism of potential tumor metastasis was also explored. MATERIALS AND METHODS: The VX-2 tumor line is an aggressive rabbit epidermoid tumor with a high metastatic potential. An initial experiment comparing cooled-tip microwave thermotherapy with cryotherapy and radical nephrectomy for treatment of small VX-2 tumors revealed that all microwave-treated rabbits had local recurrence and that several also had diffuse intraperitoneal carcinomatosis. In view of these results, a second experiment was performed in which 45 New Zealand White rabbits were implanted laparoscopically with VX-2 xenografts underneath the kidney capsule and divided into five groups of 9 each. The test groups were microwave thermotherapy with a 3.5-mm cooled-tip probe, microwave thermotherapy with a 3.5-mm noncooled- tip probe, radiofrequency ablation with a 1.5-mm cooled-tip probe, radiofrequency ablation with a 1.5- mm non-cooled tip probe, and cryotherapy with a 2.3-mm cryoprobe. The control groups were five rabbits that were not treated, five rabbits with tumors that had the tumor pierced with a probe but were untreated, and five rabbits that underwent nephrectomy after piercing of the tumor. Treatment was initiated 5 days after tumor implantation. One month later, all animals were euthanized and autopsied. RESULTS: At 5 days after tumor implantation, laparoscopic inspection revealed no visible peritoneal metastases. At 1 month, in the cooled and non-cooled microwave-thermotherapy groups, carcinomatosis occurred in five and six of nine animals, respectively. In comparison, carcinomatosis was detected in two of nine animals in the cryotherapy group at autopsy. With respect to cooled and non-cooled radiofrequency ablation, carcinomatosis was observed in four of nine rabbits in each group. In the control groups, none of the animals with unpierced tumors exhibited carcinomatosis, while carcinomatosis was seen in two of the five rabbits with tumor violated by piercing and in three of the five rabbits that underwent immediate nephrectomy after piercing of the tumor. CONCLUSION: Carcinomatosis occurred most frequently in animals treated with microwave thermotherapy, followed by radiofrequency ablation, and lastly cryoablation. The simple act of piercing a highly aggressive tumor can result in local spread. More disconcerting, and less well understood, is why certain ablative modalities appear to increase the rate of intraperitoneal spread.     

Cryosurgery and needle ablation of renal lesions

Laparoscopic renal cryoablation is a minimally invasive alternative for treating renal tumors utilizing narrow probes cooled with a compressed gas such as argon or carbon dioxide. At this time, cryotherapy has shown the most promise as an alternative to partial nephrectomy as a nephron-sparing treatment for renal tumors. Radiofrequency ablation employs needle electrodes placed percutaneously directly into renal lesions to deliver energy, creating high temperatures leading to cell death. High-intensity focused ultrasound is a noninvasive technique in which focused ultrasound energy is applied to cause cell death within the focal zone. Microwave thermotherapy uses small applicators to deliver microwave energy to tissues, resulting in the generation of heat. Although RF, HIFU, and microwave thermotherapy show promise as energy sources for tumor ablation, they are in the early stages of development. Little is known about their acute and chronic histologic effects and long-term efficacy as a treatment for malignant disease. Further work is needed to develop cryosurgery and needle ablation in order to delineate what role these techniques will ultimately play in the management of RCC.     

经皮微波和射频消融治疗肝细胞性肝癌的临床比较研究

目的探讨经皮微波和射频消融治疗肝癌临床效果的差异。方法以相同的纳入标准,回顾性比较了肝细胞性肝癌经超声引导经皮微波消融49例98个结节和射频消融53例72结节的局部疗效、并发症和远期生存率。结果微波组与射频组比较,肿瘤完全消融率分别为94.9%(93/98)和93.1%(67/72)(P=0.75),局部复发率为11.8%(11/93)和20.9%(14/67)(P=0.12)。主要并发症发生率分别为8.2%(4/49)和5.7%(3/53)(P=0.71)。1、2、3年无瘤生存率微波组分别为45.9%、26.9%和26.9%,射频组为37.2%、20.7%和15.5%(P=0.53)。1、2、3、4年累积生存率微波组分别为81.6%、61.2%、50.5%和36.8%,射频组为71.7%、47.2%、37.6%和24.2%(P= 0.12)。结论经皮微波和射频消融治疗肝癌的局部疗效、并发症和远期生存率无显著差别,均为安全有效的肝癌治疗手段。     

Update on Thermal Ablation of Renal Cell Carcinoma: Oncologic Control,Technique Comparison,Renal Function Preservation,and New Modalities

Recent studies report mid- and long-term oncologic control with thermal ablation for small renal tumors to be equivalent to surgery. Comparisons of cryoablation, radiofrequency ablation (RFA), and laparoscopic approaches to percutaneous approaches report equivalent results. Studies report little or no decrease in renal function after ablation of renal tumors. These studies support the use of percutaneous thermal ablation for treatment of small renal malignancies. Studies also report that percutaneous ablation is a safe and durable treatment of the primary tumor in stage IV patients, ultrasound guidance for percutaneous ablation can be effective, and chyluria is relatively common after RFA. Results were disappointing for newer ablation techniques, including microwave, irreversible electroporation, and high-intensity focused ultrasound. These techniques require improvements before their use in place of RFA and cryoablation. The rates of diagnostic and subtype-specific renal tumor biopsies can be improved by using both aspirate and core techniques.     

Transurethral hot water balloon thermotherapy for benign prostatic hyperplasia

For many years the transurethral prostatectomy has been the standard therapy for benign prostatic hyperplasia (BPH). In the past 10 to 15 years, a number of competing minimally invasive technologies (MIT) have been used to treat patients with symptomatic BPH. These heat-based treatments include transurethral microwave thermotherapy, interstitial devices (eg, interstitial laser coagulation and transurethral needle ablation), high-intensity focused ultrasound, and water-induced thermotherapy (WIT). This article reviews the evidence supporting the efficacy and safety of transurethral hot water balloon thermotherapy for BPH. Appropriate patient selection factors for WIT versus other MITs are reviewed. A novel combination therapy for adenocarcinoma of the prostate also is proposed.     

氩氦刀冷冻消融与射频消融在肝癌治疗中的临床应用

目的探讨氩氦刀冷冻消融与冷循环射频消融(cool-tip radiofrequency ablation,RFA)在恶性肝肿瘤治疗中的临床应用价值。方法超声引导下氩氦刀冷冻消融治疗肝癌38例共42个病灶;经超声引导下RFA治疗肝癌40例共44个病灶,治疗前后经超声造影、增强CT或增强MRI检查明确诊断及评价疗效。结果 42个病灶经一次冷冻消融治疗后32个达完全消融,10例经再次冷冻消融后达到完全消融;44个病灶经一次RFA治疗后完全消融33个,11例经再次RFA后达到完全消融。两者一次完全消融率分别为76.2%(冷冻消融)和75%(RFA),差异无统计学意义。结论氩氦刀冷冻消融和冷循环RFA均能有效地原位灭活肝癌细胞,是有效的非手术治疗恶性肝肿瘤的方法之一。     

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。     

肺磨玻璃结节诊治策略与消融治疗

肺磨玻璃结节(ground-glass nodule,GGN)是体检或偶发早期肺癌的主要表现形式,常见于年轻、女性和不吸烟人群,正确的随访与处理策略可在降低肺癌死亡率的同时避免过度治疗.持续存在的GGN大多数为腺癌或前驱腺体病变,但呈惰性生长或长期不生长,有条件的随访是十分安全的.GGN必须采取个体化诊治策略,在充分考...     

Histological findings induced by different energy sources in experimental atrial ablation in sheep

The aim of this study was a detailed comparative investigation of acute cardiac alterations induced by different energy sources and approaches in a sheep model. Experiments were performed on 39 sheep. Circular lesions were created endo- or epicardially in the left atrium and at the pulmonary veins using different energy sources: cryo, microwave, laser and unipolar or bipolar radiofrequency (RF). Electrophysiological examinations were performed immediately post treatment and 2 h after ablation to prove conduction block. Altered areas of the atria and pulmonary veins were investigated histopathologically. Endocardial ablation resulted in transmural lesions, confirmed by electrophysiological examinations. However, endocardial microwave and laser induced intensive thrombus formation, whereas radiofrequency and cryoablation induced more circumscribed necrosis and led to little endocardial thrombi. Epicardial cryoablation and microwave energy were not successful in acute phase in 8 of 9 animals. In contrast, epicardial bipolar RF was efficient and resulted in well demarcated slim lesion lines but induced marked thrombus formation. It can be summarized that surgical ablation techniques using different energy sources and approaches in this acute animal model resulted in different electrophysiological effectiveness and histomorphological lesions. Further mid and long term studies are necessary to confirm these results.     

静脉内射频消融术与激光消融术治疗大隐静脉曲张的比较

目的 比较静脉内射频消融术和激光消融术治疗大隐静脉曲张的安全性和有效性.方法 回顾性分析2018年4～12月接受静脉内射频和激光消融术治疗的80例大隐静脉曲张患者临床资料,其中射频组39例,激光组41例.比较两种方法的手术并发症发生率、术后疼痛视觉模拟评分(visual analogue scale,VAS)、静脉临床...     

An overview of energy sources in clinical use for the ablation of atrial fibrillation

Recent years have seen many developments in the field of alternative energy sources for arrhythmia surgery. The impetus behind these advances is to replace the traditional, "cut-and-sew" Cox maze III procedure with lesion sets that are simpler, shorter, and safer but just as effective. There is demand for technology to make continuous, linear, transmural ablations reliably with a versatile energy source via an epicardial approach. This would make minimally invasive endoscopic surgical ablation of atrial fibrillation (AF) without cardiopulmonary bypass and with a closed chest feasible. These advances would shorten cardio-pulmonary bypass and improve outcomes in patients having surgical ablation and concomitant cardiac surgery. This review summarizes the technology behind alternative energy sources used to treat AF. Alternative energy sources include hypothermic sources (cryoablation) and hyperthermic sources (radiofrequency, microwave, laser, ultrasound). For each source, the biophysical background, mode of tissue injury, factors affecting lesion size, and advantages and complications are discussed.     

Cryoablation vs radiofrequency ablation for the treatment of renal cell carcinoma: a meta-analysis of case series studies

Study Type – Therapy (systematic review) Level of Evidence 2b What's known on the subject? and What does the study add? The oncological success of partial nephrectomy in the treatment of small renal masses is well established. However, partial nephrectomy has largely supplanted the radical approach. In the last decade, laparoscopy has been adopted as the new surgical approach for the treatment of renal cell carcinoma. Laparoscopy offers the advantage of lower analgesic use, shorter hospital stay, and quicker recovery time. More recently, ablative technologies have been investigated as an alternative to laparoscopic partial nephrectomy. These techniques can often be performed percutaneously in the radiology suite, or laparoscopically without the need for hilar clamping. However, only the cryoablation and radiofrequency ablation modalities have had widespread use with several series reporting short to intermediate results. This review shows that both cryoablation and radiofrequency ablation are promising therapies in patients with small renal tumours (<4 cm), who are considered poor candidates for more involved surgery.

OBJECTIVE

• ? To determine the current status of the literature regarding the clinical efficacy and complication rates of cryoablation vs radiofrequency ablation in the treatment of small renal tumours.

METHODS

• ? A review of the literature was conducted. There was no language restriction. Studies were obtained from the following sources: MEDLINE, EMBASE and LILACS.
• ? Inclusion criteria were (i) case series design with more than one case reported, (ii) use of cryoablation or radiofrequency ablation, (iii) patients with renal cell carcinoma and, (iv) outcome reported as clinical efficacy.
• ? When available, we also quantified the complication rates from each included study.
• ? Proportional meta‐analysis was performed on both outcomes with a random‐effects model. The 95% confidential intervals were also calculated.

RESULTS

• ? Thirty‐one case series (20 cryoablation, 11 radiofrequency ablation) met all inclusion criteria.
• ? The pooled proportion of clinical efficacy was 89% in cryoablation therapy from a total of 457 cases. There was a statistically significant heterogeneity between these studies showing the inconsistency of clinical and methodological aspects.
• ? The pooled proportion of clinical efficacy was 90% in radiofrequency ablation therapy from a total of 426 cases. There was no statistically significant heterogeneity between these studies.
• ? There was no statistically significant difference regarding complications rate between cryoablation and radiofrequency ablation.

CONCLUSIONS

• ? This review shows that both ablation therapies have similar efficacy and complication rates.
• ? There is urgency for performing clinical trials with long‐term data to establish which intervention is most suitable for the treatment of small renal masses.

     

超声造影在肝癌射频消融治疗中的作用

目的：探讨超声造影（CEUS）在肝癌冷循环射频消融（RFA）治疗中的应用价值。方法：选取肝癌患者20例25个病灶为观察对象,RFA治疗前行CEUS确定肿瘤的性质、数目和大小,治疗后1个月内和随访10个月后行CEUS与增强CT对比疗效评价。结果：治疗后1个月内CEUS复查,20个消融病灶各期均无异常增强区,提示肿瘤完全灭活;4个边缘局部有早期增强,提示肿瘤残留,增强区经增强CT及穿刺活组织检查证实为肿瘤残留,当即补充RFA治疗;1个CEUS图像模糊,未能作出诊断。随访10个月,1个消融病灶有残留复发,4例患者行CEUS发现新生病灶11个,直径0.6-3.8 cm,其中2例4个直径〈1.0 cm的病灶增强CT未能发现。结论：CEUS可以在RFA治疗前为治疗方案提供依据,在治疗后判断RFA疗效,是一种有效方法,并有助于发现微小新病灶。