Tiziana Ierace

Radiofrequency thermal ablationof hepatic metastases

Abstract Percutaneous radiofrequency (RF) ablation is a promising therapeutic option for liver metastases, which may result in prolonged survival and chance for cure. Recent technological advancements provide larger coagulation volumes, allowing treatment of medium- and large-size metastases. Candidates are patients with metachronous liver metastases from colorectal or other primary cancers, in whom surgery is contraindicated and with one to four nodules each smaller than approx. 4 cm. We treated 109 patients with 172 colorectal metastases in the liver. Local control was obtained in 70.4% of lesions. Recurrence was significantly more frequent in lesions >3 cm. One major complication occurred (0.6% of sessions), a large bowel perforation requiring surgery. Seven minor complications did not require therapy. New metastases developed at follow-up in 50.4% of patients. Survival rates are 67% and 33% after 2 and 3 years, respectively; estimated median survival being 30 months. RF ablation advantages include minimal-invasiveness (no mortality, significantly lower complications), reduced costs and hospital stays compared to surgery, feasibility in non-surgical candidates, and the potential of repeated treatment if local recurrence occurs or new metastases develop.

Small Liver Colorectal Metastases Treated with Percutaneous Radiofrequency Ablation: Local Response Rate and Long-term Survival with Up to 10-year Follow-up

PURPOSE To determine the long-term (10-year) survival of patients with colorectal liver metastases treated with radiofrequency (RF) ablation and systemic chemotherapy with intention to treat. MATERIALS AND METHODS Institutional review board approval was obtained for this study. From 1997 to 2006, 99 consecutive patients with 202 small (0.8-4.0 cm; mean: 2.2 cm ± 1.1) metachronous colorectal liver metastases underwent ultrasonography-guided percutaneous RF ablation with internally-cooled electrodes in association with systemic chemotherapy. Patients ineligible for surgery (n = 80) or whose lesions were potentially resectable and who refused surgery (n = 19) were included. Patients were followed up with contrast agent-enhanced computed tomography and/or magnetic resonance imaging for a minimum of 3 years to more than 10 years after RF ablation (n = 99, 67, 49, and 25 for 3, 5, 7, and 10 or more years, respectively). Overall local response rates and long-term survival rates were assessed. For each of these primary endpoints, Kaplan-Meier curves were generated and log-rank tests were used to assess for statistically significant differences. RESULTS Primary and secondary technical success rates were 93.1% (188 of 202) and 100% (14 of 14), respectively. Local tumor progression occurred in 11.9% (24 of 202) metastases, and 54.2% (13 of 24) of these were re-treated. Patient survival rates increased with re-treatment versus no re-treatment (P < .001). At follow-up, 125 new liver metastases were found, and of these 32.8% (41 of 125) were treated with RF ablation. Overall survival rates were 98.0%, 69.3%, 47.8%, 25.0%, and 18.0% (median: 53.2 months) at 1, 3, 5, 7, and 10 years, respectively. The major complication rate was 1.3% (two of 156), and there were no procedure-related deaths. At the time this article was written, 32.3% (32 of 99) of the patients were alive, and 67.7% (67 of 99) were deceased, with a median follow-up of 72 months. CONCLUSION Adding RF ablation to systemic chemotherapy achieved local control in a large majority of metachronous colorectal liver metastases. The 3- to 10-year survival rates of this relatively large series of patients were essentially equivalent to those of most surgical series reported in the literature.

Percutaneous Laser Ablation of Metastatic Lymph Nodes in the Neck From Papillary Thyroid Carcinoma: Preliminary Results

CONTEXT Percutaneous laser ablation (PLA) may be useful in treating patients with metachronous metastatic lymph nodes in the neck. OBJECTIVE Our objective was to assess PLA as a treatment of difficult-to-treat metachronous cervical lymph node metastases from papillary thyroid carcinoma. DESIGN AND SETTING We conducted a retrospective analysis of prospectively collected data at a public hospital. PATIENTS Fifteen patients with previous resection of papillary thyroid carcinoma with elevated serum levels of thyroglobulin (Tg) or anti-Tg antibodies (TgAbs) and 24 metachronous nodal metastases treated between September 2010 and April 2012 were followed with [¹⁸F]fluorodeoxyglucose (¹⁸FDG) positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced ultrasound (CEUS). INTERVENTION Intervention was PLA. OUTCOME MEASURES Technique feasibility and technical success were evaluated. Tg/TgAb serum levels and ¹⁸FDG-PET/CT, and CEUS appearance were assessed at 6 and 12 months and compared with baseline. Complications were recorded. RESULTS PLA was always feasible, and technical success was achieved in all patients. At 6 months, local control was achieved in 11 of 15 patients (73%), with 6 (40%) having serum Tg/TgAb normalized (P = .017 vs baseline). Whereas 20 of 24 (83%) nodes were negative at ¹⁸FDG-PET/CT and CEUS (P < .001 vs baseline), 4 were ¹⁸FDG-PET/CT-positive (3 also CEUS-positive). At the 12-month follow-up, local control was achieved in 10 of 14 patients (71.4%). Sixteen of 20 nodes (80%) were negative at ¹⁸FDG-PET/CT and CEUS (P < .001 vs baseline), 4 were ¹⁸FDG-PET/CT-positive (2 also CEUS-positive). Four of 10 (40%) patients had normalization of serum Tg/TgAb (P = .098 vs baseline). No major complications occurred. CONCLUSIONS PLA is potentially feasible, safe, and effective for the treatment of metachronous cervical nodal metastases from papillary thyroid carcinoma. This procedure may reduce or delay a large number of highly invasive repeat neck dissections.

Benign thyroid nodules treatment using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA)

Abstract Purpose: To evaluate the reduction over time of benign thyroid nodules treated using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA) by the same equipe. Materials and methods: Ninety patients (age 55.6 ± 14.1 years) underwent ablation for benign thyroid nodule causing compression/aesthetic dissatisfaction from 2011. Fifty-nine (age 55.8 ± 14.1 years) underwent RFA and 31 (age 55.2 ± 14.2 years) PLA, ultrasound guided. Technical success, complications, duration of ablation and treatment, energy deployed, volumetric percentage reduction at 1, 6 and 12 months were derived. A regression model for longitudinal measurements was used with random intercept and random slope. Values are expressed as mean ± standard deviation or N (%). Results: Technical success was always obtained. No major complications occurred. Mean ablation time was 30.1 ± 13.8 vs. 13.9 ± 5.9 min (p < .0001) and mean energy deployment was 5422.3 ± 2484.5 J vs. 34 662.7 ± 15 812.3 J in PLA vs. RFA group. Mean volume reduced from 20.3 ± 16.4 ml to 13.17 ± 10.74 ml (42% ± 17% reduction) at 1st month, 8.7 ± 7.4 ml (60% ± 15% reduction) at 6th month and 7.1 ± 7.7 ml (70%% ± 16% reduction) at 12th month, in PLA group, and from 32.7 ± 19.5 ml to 17.2 ± 12.9 ml (51%±15% reduction) at 1st month, 12.8 ± 9.6 ml (64 ± 14% reduction) at 6th month and 9.9 ± 9.2 ml (74% ± 14% reduction) at 12th month in RFA group. No difference in time course of the relative volume reduction between the two techniques was found. Conclusions: RFA and PLA are similarly feasible, safe and effective in treating benign thyroid nodules when performed by the same equipe. RFA is faster than PLA but require significantly higher energy.

Liver cancer imaging : The need for accurate detection of intrahepatic disease spread

The last ten years have seen dramatic changes in the therapeutic approach to both primary (i.e., hepatocellular carcinoma: HCC) and secondary (i.e., metastatic lesions) focal liver malignancies. This has been due to the increasing proliferation of new modalities, including percutaneous ablative therapies (ethanol injection: PEI; radiofrequency: RF; laser; microwaves), angiographic therapies (segmental chemoembolization; hypoxic perfusion) and liver transplantation (OLT), in addition to a greater acceptance of pre-existing modalities (resection; systemic chemotherapy). Thus, a main aim of current medical management is to select for each patient the therapeutic modality which will provide the highest success rate, fewest risks and lowest costs for each given situation. However, in order to decide on the appropriate therapeutic choice, the accurate diagnosis of neoplastic lesions by means of one or more imaging modalities (ultrasound: US; computed tomography: CT; magnetic resonance: MR) is mandatory. This imaging work-up can be viewed as having three purposes: lesion detection, lesion characterization, intrahepatic and extrahepatic cancer staging. The present paper is concerned primarily with the imaging approach to liver lesion detection.

Microwave ablation of primary and secondary liver tumours: ex vivo, in vivo, and clinical characterisation

Abstract Purpose: The aim of this study was to compare the performance of a microwave ablation (MWA) apparatus in preclinical and clinical settings. Materials and method: The same commercial 2.45 GHz MWA apparatus was used throughout this study. In total 108 ablations at powers ranging from 20 to 130 W and lasting from 3 to 30 min were obtained on ex vivo bovine liver; 28 ablations at 60 W, 80 W and 100 W lasting 5 and 10 min were then obtained in an in vivo swine model. Finally, 32 hepatocellular carcinomas (HCCs) and 19 liver metastases in 46 patients were treated percutaneously by administering 60 W for either 5 or 10 min. The treatment outcome was characterised in terms of maximum longitudinal and transversal axis of the induced ablation zone. Results: Ex vivo ablation volumes increased linearly with deposited energy (r2 = 0.97), with higher sphericity obtained at lower power for longer ablation times. Larger ablations were obtained on liver metastases compared to HCCs treated with 60 W for 10 min (p < 0.003), as ablation diameters were 4.1 ± 0.6 cm for metastases and 3.7 ± 0.3 cm for HCC, with an average sphericity index of 0.70 ± 0.04. The results on the in vivo swine model at 60 W were substantially smaller than the ex vivo and clinical results (either populations). No statistically significant difference was observed between ex vivo results at 60 W and HCC results (p > 0.08). Conclusions: For the selected MW ablation device, ex vivo data on bovine liver was more predictive of the actual clinical performance on liver malignancies than an in vivo porcine model. Equivalent MW treatments yielded a significantly different response for HCC and metastases at higher deposited energy, suggesting that outcomes are not only device-specific but must also be characterised on a tissue-by-tissue basis.

Guidance of Percutaneous Tumor Ablation Procedures

Diagnostic imaging plays a key role in all steps of radiofrequency (RF) tumor ablation. It is used in the following ways: 1) detection of lesions and selection of patients for treatment; 2) targeting of lesions and guidance of the procedure; 3) immediate assessment of treatment results; 4) long-term follow-up. Conventional, unenhanced ultrasound (US) is widely employed for screening liver disease, but variable sensitivity and well-known drawbacks limit its role in the staging of liver tumors. Furthermore, sonography represents the most commonly used imaging modality for the guidance of percutaneous ablative treatments owing to its availability, rapidity and ease of use. Differentiation of induced necrosis from a viable tumor is not possible with baseline and color Doppler sonography and therefore the immediate and long-term assessment of the therapeutic result is usually accomplished by contrastenhanced helical computer tomography (CT) and magnetic resonance (MR). In our experience, the use of contrastenhanced ultrasound (CEUS) represents a significant improvement over conventional US for each of above-mentioned steps and has proven useful in achieving optimal patient management and treatment results [1].

Ablation of Liver Metastases

Metastatic liver disease represents one of the most common clinical problems in oncology practice. Multiple treatment options are available including hepatic resection, chemoembolization, intraarterial and systemic chemotherapy, cryotherapy, and radiofrequency ablation (RFA) (1,2).

Guida alla terapia ablativa percutanea nei tumori epatici

Numerosi tipi di terapia ablativa applicabili principalmente per via percutanea sono attualmente disponibili per i tumori primitivi e metastatici del fegato: quelli che utilizzano l’energia termica (in particolare la termoablazione con radiofrequenza) hanno oggi la maggiore diffusione e le casistiche piu ampie.

Tumor Ablation Using Radiofrequency Energy

Radiofrequency ablation is used for the treatment of a variety of neoplasms including: osteoid osteoma, hepatocellular carcinoma, renal cell carcinoma, bronchopulmonary carcinoma, parathyroid adenoma;1 hepatic and retroperitoneal metastases from a variety of primary tumors. The size of the coagulation zone is a crucial factor, as only a complete coagulation of the tumor including a sufficient safety zone inhibits local recurrence. Thus many efforts have been made to enlarge the coagulation zone using multiprobe arrays, saline perfusion, internal cooling, bipolar technique, pulsed application or a combination of these mentioned techniques. Tumors up to 5 cm can now be effectively treated, taking inclusion and exclusion criteria into account. Lately published data suggests that RF ablation is far more than an electro-physical tool to generate a thermal tumor destruction, it also induces a significant activation of tumor-specific T lymphocytes.