David J Breen

Percutaneous cryoablation of renal tumours: outcomes from 171 tumours in 147 patients

To evaluate the technical and oncological efficacy of an image‐guided cryoablation programme for renal tumours.

Arterialised hepatic nodules in the Fontan circulation: hepatico-cardiac interactions.

Hypervascular nodules occur commonly when there is hepatic venous outlet obstruction. Their nature and determinants in the Fontan circulation is poorly understood. We reviewed the records of 27 consecutive Fontan patients who had computerized tomography scan (CT) over a 4 year period for arterialised nodules and alterations in hepatic flow patterns during contrast enhanced CT scans and related these findings to cardiac characteristics. Mean patient age was 24 ± 5.8 years, (range 16.7-39.8) and mean Fontan duration was 16.8 ± 4.8 years (range 7.3-28.7). Twenty-two patients demonstrated a reticular pattern of enhancement, 4 a zonal pattern and only 1 demonstrated normal enhancement pattern. Seven (26%) patients had a median of 4 (range 1-22) arterialised nodules, mean size 1.8 cm (range 0.5 to 3.2 cm). All nodules were located in the liver periphery, their outer aspect lying within 2 cm of the liver margin. Patients with nodules had higher mean RA pressures (18 mmHg ± 5.6 vs. 13 mmHg ± 4, p=0.025), whereas their mixed venous saturation and aortic saturation was not significantly different (70% ± 11 vs. 67% ± 9 and 92% ± 10 vs. 94% ± 4, p>0.05). Post-mortem histology suggests focal nodular hyperplasia is the underlying pathology. ConclusionsAbnormalities of hepatic blood flow and the presence of arterialised nodules are common in the failing Fontan circulation. They occur especially when central venous pressures are high, and very likely indicate arterialisation of hepatic blood flow and reciprocal portal venous deprivation. The underlying pathology is most likely focal nodular hyperplasia.

Image-guided ablation of primary liver and renal tumours

Image-guided ablation (IGA) techniques have evolved considerably over the past 20 years and are increasingly used to definitively treat small primary cancers of the liver and kidney. IGA is recommended by most guidelines as the best therapeutic choice for patients with early stage hepatocellular carcinoma (HCC)—defined as either a single tumour smaller than 5 cm or up to three nodules smaller than 3 cm—when surgical options are precluded, and has potential as first-line therapy, in lieu of surgery, for patients with very early stage tumours smaller than 2 cm. With regard to renal cell carcinoma, despite the absence of any randomized trial comparing the outcomes of IGA with those of standard partial nephrectomy, a growing amount of data demonstrate robust oncological outcomes for this minimally invasive approach and testify to its potential as a standard-of-care treatment. Herein, we review the various ablation techniques, the supporting evidence, and clinical application of IGA in the treatment of primary liver and kidney cancers.

Minimally Invasive Treatment of Small Renal Tumors: Trends in Renal Cancer Diagnosis and Management

Renal cell carcinoma is a common malignancy causing significant mortality. In recent years abdominal imaging, often for alternate symptomatology, has led the trend toward the detection and confirmation of smaller renal tumors. This has permitted the greater use of localized and nephron-sparing techniques including partial nephrectomy and image-guided ablation. This article aims to review the current role of image-guided biopsy and ablation in the management of small renal tumors. The natural history of renal cell carcinoma, the role of renal biopsy, the principles and procedural considerations of thermal energy ablation, and the oncological outcomes of these minimally invasive treatments are discussed and illustrated with cases from the authors’ institution. Image-guided ablation, in particular, has changed the treatment paradigm and, by virtue of its increasingly evident efficacy and low morbidity, now favors the treatment of smaller tumors in patients previously unfit for surgery.

The clinical effectiveness and cost-effectiveness of ablative therapies in the management of liver metastases: systematic review and economic evaluation.

BACKGROUNDnMany deaths from cancer are caused by metastatic burden. Prognosis and survival rates vary, but survival beyond 5 years of patients with untreated metastatic disease in the liver is rare. Treatment for liver metastases has largely been surgical resection, but this is feasible in only approximately 20-30% of people. Non-surgical alternatives to treat some liver metastases can include various forms of ablative therapies and other targeted treatments.nnnOBJECTIVESnTo evaluate the clinical effectiveness and cost-effectiveness of the different ablative and minimally invasive therapies for treating liver metastases.nnnDATA SOURCESnElectronic databases including MEDLINE, EMBASE and The Cochrane Library were searched from 1990 to September 2011. Experts were consulted and bibliographies checked.nnnREVIEW METHODSnSystematic reviews of the literature were undertaken to appraise the clinical effectiveness and cost-effectiveness of ablative therapies and minimally invasive therapies used for people with liver metastases. Studies were any prospective study with sample size greater than 100 participants. A probabilistic model was developed for the economic evaluation of the technologies where data permitted.nnnRESULTSnThe evidence assessing the clinical effectiveness and cost-effectiveness of ablative and other minimally invasive therapies was limited. Nine studies of ablative therapies were included in the review; each had methodological shortcomings and few had a comparator group. One randomised controlled trial (RCT) of microwave ablation versus surgical resection was identified and showed no improvement in outcomes compared with resection. In two prospective case series studies that investigated the use of laser ablation, mean survival ranged from 41 to 58 months. One cohort study compared radiofrequency ablation with surgical resection and five case series studies also investigated the use of radiofrequency ablation. Across these studies the median survival ranged from 44 to 52 months. Seven studies of minimally invasive therapies were included in the review. Two RCTs compared chemoembolisation with chemotherapy only. Overall survival was not compared between groups and methodological shortcomings mean that conclusions are difficult to make. Two case series studies of laser ablation following chemoembolisation were also included; however, these provide little evidence of the use of these technologies in combination. Three RCTs of radioembolisation were included. Significant improvements in tumour response and time to disease progression were demonstrated; however, benefits in terms of survival were equivocal. An exploratory survival model was developed using data from the review of clinical effectiveness. The model includes separate analyses of microwave ablation compared with surgery and radiofrequency ablation compared with surgery and one of radioembolisation in conjunction with hepatic artery chemotherapy compared with hepatic artery chemotherapy alone. Microwave ablation was associated with an incremental cost-effectiveness ratio (ICER) of £3664 per quality-adjusted life-year (QALY) gained, with microwave ablation being associated with reduced cost but also with poorer outcome than surgery. Radiofrequency ablation compared with surgical resection for solitary metastases <u20093u2009cm was associated with an ICER of -£266,767 per QALY gained, indicating that radiofrequency ablation dominates surgical resection. Radiofrequency ablation compared with surgical resection for solitary metastases ≥u20093u2009cm resulted in poorer outcomes at lower costs and a resultant ICER of £2538 per QALY gained. Radioembolisation plus hepatic artery chemotherapy compared with hepatic artery chemotherapy was associated with an ICER of £37,303 per QALY gained.nnnCONCLUSIONSnThere is currently limited high-quality research evidence upon which to base any firm decisions regarding ablative therapies for liver metastases. Further trials should compare ablative therapies with surgery, in particular. A RCT would provide the most appropriate design for undertaking any further evaluation and should include a full economic evaluation, but the group to be randomised needs careful selection.nnnSOURCE OF FUNDINGnFunding for this study was provided by the Health Technology Assessment programme of the National Institute for Health Research.

Percutaneous image-guided cryoablation of small renal masses.

Renal cell carcinoma is a common malignancy with increasing incidence due to the incidental detection of non-symptomatic small renal masses on imaging. Management of these small tumors has evolved toward minimally invasive nephron-sparing techniques which include partial nephrectomy and image-guided ablation. Cryoablation and radiofrequency ablation are the most utilized ablation modalities with the former more suited for larger and central renal masses due to intra-procedural visualization of the ablation zone and reduced pelvicalyceal injury. In this article, we review the epidemiology and natural history of renal cell carcinoma, the role of biopsy, and the management options available—surgery, image-guided ablation, and active surveillance—with a focus on cryoablation. The clinical outcomes of the longer term maturing cryoablation data are discussed with reference to partial nephrectomy and radiofrequency ablation. Image-guided ablation has often been the management choice in patients deemed unfit for surgery; however, growing evidence from published series demonstrates image-guided ablation as a sound alternative treatment with equivalent oncological outcomes and minimal patient impact.

No-touch Wedge Ablation Technique of Microwave Ablation for the Treatment of Subcapsular Tumors in the Liver

Ablation of exophytic and border-deforming liver tumors may increase risks of tumor seeding or hemorrhage. The present report describes a no-touch wedge ablation technique intended to potentially reduce tumor disruption while achieving technically adequate ablation. The technique involves the use of multiple probe positions tangential to the tumor, and was used to treat eight tumors. Complete ablation was demonstrated in all cases on early posttreatment imaging at an average of 16 days after the procedure. At an average imaging follow-up of 244 days, there was one case of local tumor recurrence. The technique may be useful for the ablation of exophytic, border-deforming liver tumors.

Understanding the current status of image-guided ablation for metastatic colorectal disease

Colorectal metastases to the liver are increasingly being detected and accurately characterized at an earlier stage and even at the subcentimeter level. The oncological case for surgical resection of this disease is widely accepted. The advent of smaller volume disease has encouraged the development of in situ ablative technologies over the last two decades and the oncological efficacy of these procedures has continued to improve through stepwise developments in ablation devices and image guidance. This article provides an overview of these techniques, currently available and future technologies, and the imaging findings encountered. It also sets out the current position image-guided ablation merits alongside chemotherapy and surgical resection. In selected cases ablation for colorectal metastases can produce oncological outcomes equivalent to surgery and critically with less morbidity in an increasingly older patient population. We examine whether with careful patient selection, optimal technology, meticulous technique, and diligent follow-up, consistently reproducible high quality outcomes will be achieved in the next few years.

Transarterial Embolization and Doxorubicin Eluting Beads- Transarterial Chemoembolization (DEB-TACE) of Malignant Extra-Adrenal Pheochromocytoma

Extra-adrenal pheochromocytomas (EAPs) are neuroendocrine tumors that arise from paraganglion cells of the sympathetic component of the autonomic nervous system. The paraganglia are chromaffin tissue complexes that extend along the paravertebral axis [1]. As part of the autonomic nervous system, these paraganglia are the dominant source of catecholamine production during early childhood [2]. Failure of involution of these paraganglia leads to the development of extra-adrenal pheochromocytomas. The majority of intra-abdominal paragangliomas present at the organ of Zuckerkandl (to the left of the aorta near the inferior mesenteric artery takeoff). Tumors below the diaphragm are typically functional with symptoms relating to excess catecholamine secretion. Generally, patients report nonspecific symptoms, such as headaches, sweating, palpitation, anxiety, and tremors. Biochemical workup demonstrates elevated levels of plasma and urinary catecholamines and their metabolites. Provided there is no contraindication, a contrastenhanced CT should be the initial imaging modality because it is readily available and highly sensitive. Scintigraphy with I-labelled metaiodobenzylguanidine (I-MIBG) is the most common functional study used. The treatment traditionally consists of open or laparoscopic exploration and resection with preoperative a and b blockade [3]. It is now known that EAPs demonstrate potential malignant change in up to 50% of patients, far greater than the 10% reported for pheochromocytomas [4]. Because there are no pathognomonic histological findings that distinguish benignity from malignancy, the diagnosis of malignant transformation is made on the basis of the development of recurrence or metastases and presence of lymph nodes.

Morphometric and chronological behavior of 2.45 GHz microwave ablation zones for colorectal cancer metastases and hepatocellular carcinoma in the liver: preliminary report

BackgroundPercutaneous microwave ablation (MWA) is increasingly utilized in the treatment of primary and secondary hepatic malignancy. As an in-situ treatment appreciation of any signs of recurrence is critical for improving long-term oncological outcomes. Volumetry has been recognized as having advantages over orthogonal measurements in the response assessment of malignant lesions. Our study set out to look at the normal involution of an ablation zone (AZ) both volumetrically and morphologically to see if this information might aid the detection of local tumor progression.MethodsCases were identified retrospectively from our database of liver MWA. We identified 34 AZs in total, 18 AZs in 16 hepatocellular carcinoma (HCC) patients with cirrhosis on imaging grounds and 13 AZs in patients with metastatic colorectal cancer. How these AZs developed over time was analyzed both morphologically and quantitatively using Siemens Syngo Via post-processing software. We used the software to produce volume measurements and short axis orthogonal measurements. A baseline measurement was taken on the first <30xa0day post-ablation scan and the chronological changes were then plotted.ResultsWe saw differences between the cirrhotic and non-cirrhotic patients both in terms of morphological and volumetric changes. 12/13 non-cirrhotic AZs had a volume of <50% of the baseline scan within the first year. The cirrhotic patients were less predictable, but 14/18 still shrunk to less than 50% of baseline volume in the first year. Orthogonal measurements were less useful in both groups. Qualitatively, there was initially a slightly less well-defined border to the AZ in the first 3xa0months, which became better defined over time and certainly over the first year of AZ involution.ConclusionVolumetric analysis is a useful adjunct to conventional measurements and qualitative analysis of AZs. This can be reassuring when orthogonal measurements are static or difficult to interpret. Our preliminary data suggest that the normal pattern in a non-cirrhotic liver is that the AZ volume should drop below 50% of baseline at 1xa0year. Volumes in cirrhotic livers are less predictable, but the majority will still follow a similar pattern. Future studies could evaluate if failure to follow these patterns correlates with local tumor progression.