Percutaneous Liver Tumour Ablation: Image Guidance, Endpoint Assessment, and Quality Control

Cardiac tamponade after radiofrequency ablation for hepatocellular carcinoma: Case report and literature review

RATIONALE

Radiofrequency ablation (RFA) is a safe and effective local treatment modality with a low complication rate and is commonly used to treat hepatocellular carcinoma (HCC). The clinical outcome of RFA may be closely related to the location, size, and shape of index tumors, and major complications, including hemorrhage, liver abscess, infarction, visceral organ perforation, hemothorax, pneumothorax, tumoral seeding, and hepatic failure. Cardiac tamponade is a rare and serious life-threatening complication associated with RFA. To date, a review of the medical literature reported 5 cases of cardiac tamponade after RFA for HCC. Herein, we report another case of cardiac tamponade after RFA for HCC in a 56-year-old man.

PATIENT CONCERNS

He had suffered from liver cirrhosis due to alcohol abuse. He had chronic obstructive pulmonary disease. Magnetic resonance imaging showed a 3.0-cm exophytic subcapsular HCC in segment IVa of left hepatic lobe. As the patient was at high risk for surgery because of poor lung function, RFA was selected as the treatment of choice. The index tumor was located in the vicinity of the diaphragm and colon. During RFA procedure, thermal injury to the adjacent diaphragm and colon was minimized by introducing artificial ascites. Bleeding or tumoral seeding was prevented by ablating the electrode track during electrode retraction.

DIAGNOSIS

Two hours after RFA, the patient presented with dyspnea, chest discomfort, and low blood pressure (80/60 mm Hg), suggesting cardiac tamponade. Immediate follow-up contrast-enhanced computed tomography image depicted the slightly high attenuated hemopericardium. Transthoracic echocardiography (TTE) showed a moderate amount of pericardial effusion with tamponade and a large hematoma.

INTERVENTIONS

Under fluoroscopy and portable echocardiography guidance, a cardiologist immediately inserted a 7-French pigtail catheter into the pericardial space and collected more than 200 cc of bloody pericardial fluid.

OUTCOMES

After pericardiocentesis, the patient's symptoms and hemodynamic status were dramatically improved. Follow-up TTE showed scanty amount of pericardial effusion and the drainage catheter was removed. The patient was discharged.

LESSONS

When treating HCC in the left lobe (especially segments II and IVa), attention should be paid to cardiac tamponade. The early diagnosis and immediate treatment of cardiac tamponade may increase the chance of cure.

An overview of interventional strategies for the management of oncologic pain

Pain is a ubiquitous part of the cancer experience. Often the presenting symptom of malignancy, pain becomes more prevalent in advanced or metastatic disease and often persists despite curative treatment. Although management of cancer pain improved following publication of the WHO's analgesic ladder, when used in isolation, conservative approaches often fail to control pain and are limited by intolerable side effects. Interventional strategies provide an option for managing cancer pain that remains refractory to pharmacologic therapy. The purpose of this review is to investigate these strategies and discuss the risks and benefits which must be weighed when considering their use. Therapies anticipated to have an increasingly important role in the future of cancer pain management are also discussed.

Volumetric 3D assessment of ablation zones after thermal ablation of colorectal liver metastases to improve prediction of local tumor progression

PURPOSE

The goal of this study was to develop and evaluate a volumetric three-dimensional (3D) approach to improve the accuracy of ablation margin assessment following thermal ablation of hepatic tumors.

METHODS

The 3D margin assessment technique was developed to generate the new 3D assessment metrics: volumes of insufficient coverage (VICs) measuring volume of tissue at risk post-ablation. VICs were computed for the tumor and tumor plus theoretical 5- and 10-mm margins. The diagnostic accuracy of the 3D assessment to predict 2-year local tumor progression (LTP) was compared to that of manual 2D assessment using retrospective analysis of a patient cohort that has previously been reported as a part of an outcome-centered study. Eighty-six consecutive patients with 108 colorectal cancer liver metastases treated with radiofrequency ablation (2002-2012) were used for evaluation. The 2-year LTP discrimination power was assessed using receiver operating characteristic area under the curve (AUC) analysis.

RESULTS

A 3D assessment of margins was successfully completed for 93 out of 108 tumors. The minimum margin size measured using the 3D method had higher discrimination power compared with the 2D method, with an AUC value of 0.893 vs. 0.790 (p = 0.01). The new 5-mm VIC metric had the highest 2-year LTP discrimination power with an AUC value of 0.923 (p = 0.004).

CONCLUSIONS

Volumetric semi-automated 3D assessment of the ablation zone in the liver is feasible and can improve accuracy of 2-year LTP prediction following thermal ablation of hepatic tumors.

KEY POINTS

• More accurate prediction of local tumor progression risk using volumetric 3D ablation zone assessment can help improve the efficacy of image-guided percutaneous thermal ablation of hepatic tumors. • The accuracy of evaluation of ablation zone margins after thermal ablation of colorectal liver metastases can be improved using a volumetric 3D semi-automated assessment approach and the volume of insufficient coverage assessment metric. • The new 5-mm volume-of-insufficient-coverage metric, indicating the volume of tumor plus 5-mm margin that remained untreated, had the highest 2-year local tumor progression discrimination power.

Colorectal liver metastases: surgery versus thermal ablation (COLLISION) - a phase III single-blind prospective randomized controlled trial

Background

Radiofrequency ablation (RFA) and microwave ablation (MWA) are widely accepted techniques to eliminate small unresectable colorectal liver metastases (CRLM). Although previous studies labelled thermal ablation inferior to surgical resection, the apparent selection bias when comparing patients with unresectable disease to surgical candidates, the superior safety profile, and the competitive overall survival results for the more recent reports mandate the setup of a randomized controlled trial. The objective of the COLLISION trial is to prove non-inferiority of thermal ablation compared to hepatic resection in patients with at least one resectable and ablatable CRLM and no extrahepatic disease.

Methods

In this two-arm, single-blind multi-center phase-III clinical trial, six hundred and eighteen patients with at least one CRLM (≤3 cm) will be included to undergo either surgical resection or thermal ablation of appointed target lesion(s) (≤3 cm). Primary endpoint is OS (overall survival, intention-to-treat analysis). Main secondary endpoints are overall disease-free survival (DFS), time to progression (TTP), time to local progression (TTLP), primary and assisted technique efficacy (PTE, ATE), procedural morbidity and mortality, length of hospital stay, assessment of pain and quality of life (QoL), cost-effectiveness ratio (ICER) and quality-adjusted life years (QALY).

Discussion

If thermal ablation proves to be non-inferior in treating lesions ≤3 cm, a switch in treatment-method may lead to a reduction of the post-procedural morbidity and mortality, length of hospital stay and incremental costs without compromising oncological outcome for patients with CRLM.

Trial registration

NCT03088150, January 11th 2017.