Percutaneous Radiofrequency Ablation Combined with Previous Bronchial Arterial Chemoembolization and Followed by Radiation Therapy for Pulmonary Metastasis from Hepatocellular Carcinoma

Percutaneous CT-guided radiofrequency ablation for patients with extrahepatic oligometastases of hepatocellular carcinoma: long-term results

BACKGROUND

The aim of this study was to evaluate the therapeutic outcome of percutaneous computed tomography (CT)-guided radiofrequency ablation (RFA) for extrahepatic oligometastases of hepatocellular carcinoma (HCC).

METHODS

Institutional review board approval was obtained for this retrospective study, and all patients provided written informed consent. Between April 2004 and December 2015, 116 oligometastases (diameter, 5-50 mm; 20.3 ± 10.4) in 79 consecutive HCC patients (73 men and 6 women; average age, 50.3 years ±13.0) were treated with RFA. We focussed on patients with 1-3 extrahepatic metastases (EHM) confined to 1-2 organs (including the lung, adrenal gland, bone, lymph node and pleura/peritoneum) who were treated naïve with curative intent. Survival, technical success and safety were evaluated. The log-rank test and Cox proportional hazards regression models were used to analyse the survival data.

RESULTS

No immediate technical failure occurred, and at 1 month, the technique effectiveness rate was determined to be 95.8%. After a median follow-up time of 28.0 months (range, 6-108 months), the 1-, 2- and 3-year overall survival (OS) rates were 91, 70 and 48%, respectively, with a median survival time of 33.5 months. Time to unoligometastatic progression (TTUP) of less than 6 months (p < 0.001) and a Child-Pugh score of more than 5 (p = 0.001) were significant indicators of shorter OS. The 1-, 2- and 3-year disease free survival (DFS) rates were 34, 21 and 8%, respectively, with a median DFS time of 6.8 months. DFS was better for those with lung metastases (p = 0.006). Major complication occurred in nine (9.5%, 9/95) RFA sessions without treatment-related mortality.

CONCLUSIONS

CT-guided RFA for oligometastatic HCC may provide favourable efficacy and technical success with a minimally invasive approach.

Lung cancer ablation: what is the evidence?

Percutaneous ablation of small non-small cell lung cancer (NSCLC) has been demonstrated to be both feasible and safe in nonsurgical candidates. Radiofrequency ablation (RFA), the most commonly used technique for ablation, has a reported rate of complete ablation of ~90%, with best results obtained in tumors <2 to 3 cm in diameter. The best reported 1-, 3-, and 5-year overall survival rates after RFA of NSCLC are 97.7%, 72.9%, and 55.7%, respectively. It is noteworthy that in most studies, cancer-specific survival is greater than overall survival due to severe comorbidities in patients treated with RFA for NSCLC. Aside from tumor size and tumor stage, these comorbidities are predictive of survival. Other ablation techniques such as microwave and irreversible electroporation may in the future prove to overcome some of the limitations of RFA, namely for large tumors or tumors close to large vessels. Stereotactic body radiation therapy has also been demonstrated to be highly efficacious in treating small lung tumors and will need to be compared with percutaneous ablation. This article reviews the current evidence regarding RFA for lung cancer.

Palliative radiation therapy for pulmonary metastases from hepatocellular carcinoma

Although the lung is the most common site of extrahepatic metastases from hepatocellular carcinoma (HCC), the optimal treatment for such metastases has'nt been established. External beam radiotherapy (EBRT) is becoming a useful local control therapy for lung cancer. To evaluated the efficacy of EBRT treatment for such metastases, we retrospectively studied 13 patients (11 men and 2 women; mean age, 52.6 years) with symptomatic pulmonary metastases from HCC who had been treated with EBRT in our institution. The palliative radiation dose delivered to the lung lesions ranged from 47 to 60 Gy (median 50) in conventional fractions, while the intrahepatic lesions were treated with surgery or transarterial chemoembolization, and/or EBRT. Follow-up period from radiotherapy ranged from 3.7 to 49.1 months (median, 16.7). Among the 13 patients, 23 out of a total of 31 pulmonary metastatic lesions received EBRT. In 12/13(92.3%) patients, significant symptoms were completely or partially relieved. An objective response was observed in 10/13(76.9%) of the subjects by computed tomography imaging. The median progression-free survival for all patients was 13.4 months. The 2-year survival rate from pulmonary metastasis was 70.7%. Adverse effects were mild and consisted of bone marrow suppression in three patients and pleural effusion in one patient (all CTCAE Grade II). In conclusion, EBRT with ≤60 Gy appears to be a good palliative therapy with reasonable safety for patients with pulmonary metastases from HCC. However, large-scale randomized clinical trials will be necessary to confirm the therapeutic role of this method.

Takao Hiraki’s work on interventional radiology

Dr. Takao Hiraki is a scientist carrying out interventional radiology research in the Department of Radiology at Okayama University Medical School, Japan. He has conducted animal and human clinical studies on interventional radiology for various conditions. For example, he clarified the hepatic hemodynamic changes caused by hepatic venous occlusion. He also developed new devices, such as hydrogel coils for the occlusion of the aneurismal sac after an endovascular stent-graft of an aortic aneurysm to prevent endoleakage and small intestinal submucosa-covered stents for transjugular intrahepatic portosystemic shunts. Further, he performed a number of studies on the radiofrequency ablation of lung cancer, mediastinal lymph node metastasis, and computed tomography-fluoroscopy-guided lung biopsies. He intends to continue to dedicate his academic career to expand the role of interventional radiology in clinical medicine.

Lung tumor radiofrequency ablation: where do we stand?

Today, radiofrequency ablation (RFA) of primary and metastatic lung tumor is increasingly used. Because RFA is most often used with curative intent, preablation workup must be a preoperative workup. General anesthesia provides higher feasibility than conscious sedation. The electrode positioning must be performed under computed tomography for sake of accuracy. The delivery of RFA must be adapted to tumor location, with different impedances used when treating tumors with or without pleural contact. The estimated rate of incomplete local treatment at 18 months was 7% (95% confidence interval, 3-14) per tumor, with incomplete treatment depicted at 4 months (n = 1), 6 months (n = 2), 9 months (n = 2), and 12 months (n = 2). Overall survival and lung disease-free survival at 18 months were, respectively, 71 and 34%. Size is a key point for tumor selection because large size is predictive of incomplete local treatment and poor survival. The ratio of ablation volume relative to tumor volume is predictive of complete ablation. Follow-up computed tomography that relies on the size of the ablation zone demonstrates the presence of incomplete ablation. Positron emission tomography might be an interesting option. Chest tube placement for pneumothorax is reported in 8 to 12%. Alveolar hemorrhage and postprocedure hemoptysis occurred in approximately 10% of procedures and rarely required specific treatment. Death was mostly related to single-lung patients and hilar tumors. No modification of forced expiratory volume in the first second between pre- and post-RFA at 2 months was found. RFA in the lung provides a high local efficacy rate. The use of RFA as a palliative tool in combination with chemotherapy remains to be explored.

Determinants of local progression after computed tomography-guided percutaneous radiofrequency ablation for unresectable lung tumors: 9-year experience in a single institution

The purpose of this study was to retrospectively determine the local control rate and contributing factors to local progression after computed tomography (CT)-guided radiofrequency ablation (RFA) for unresectable lung tumor. This study included 138 lung tumors in 72 patients (56 men and 16 women; age 70.0 +/- 11.6 years (range 31-94); mean tumor size 2.1 +/- 1.2 cm [range 0.2-9]) who underwent lung RFA between June 2000 and May 2009. Mean follow-up periods for patients and tumors were 14 and 12 months, respectively. The local progression-free rate and survival rate were calculated to determine the contributing factors to local progression. During follow-up, 44 of 138 (32%) lung tumors showed local progression. The 1-, 2-, 3-, and 5-year overall local control rates were 61, 57, 57, and 38%, respectively. The risk factors for local progression were age (>or=70 years), tumor size (>or=2 cm), sex (male), and no achievement of roll-off during RFA (P < 0.05). Multivariate analysis identified tumor size >or=2 cm as the only independent factor for local progression (P = 0.003). For tumors <2 cm, 17 of 68 (25%) showed local progression, and the 1-, 2-, and 3-year overall local control rates were 77, 73, and 73%, respectively. Multivariate analysis identified that age >or=70 years was an independent determinant of local progression for tumors <2 cm in diameter (P = 0.011). The present study showed that 32% of lung tumors developed local progression after CT-guided RFA. The significant risk factor for local progression after RFA for lung tumors was tumor size >or=2 cm.

Radiofrequency thermocoagulation of lung tumours. Where we are, where we are headed

Only 25% of all lung cancers are diagnosed in an early stage allowing surgical treatment. Primary tumours usually concerning lung metastasis are breast, colon, kidney, uterus/cervix, prostate, and head and neck tumours. During recent years many publications have confirmed the effectiveness and reliability of lung radiofrequency ablation (RFA) alone or together with other techniques (chemotherapy, radiotherapy...). Results suggest that survival increase and curative rates of lung radiofrequency are similar to those achieved by more aggressive procedures and present lower rates of complications. Pneumothorax, pleural effusion and alveolar haemorrhage are the most frequent complications. Indications for lung RFA must be individually evaluated by lung cancer committees. Percutaneous lung RFA may be useful in patients with pulmonary primary tumours and metastases, especially in those with nodules smaller than 3 cm and a peripheral location (>1 cm from the hilum). PET/CT seems to be the most accurate technique in patient follow up.

Percutaneous radiofrequency ablation of lung tumors close to the heart or aorta: evaluation of safety and effectiveness

PURPOSE

The authors retrospectively evaluated the safety and effectiveness of percutaneous radiofrequency ablation of lung tumors close to the heart or aorta.

MATERIALS AND METHODS

Forty-two tumors (mean diameter, 25 mm +/- 16; range, 5-73 mm) located less than 10 mm from the heart or aorta were treated with radiofrequency ablation in 47 sessions. Lung tumors were classified into two groups according to their distance from the heart or aorta: group A (n = 27) comprised tumors at a distance of 1-9 mm; group B (n = 15) comprised contiguous tumors (distance, 0 mm). The safety and technique effectiveness of the procedure, defined as no evidence of local tumor progression, were evaluated.

RESULTS

Radiofrequency ablation was feasible for all the 42 tumors. Procedural complications included asymptomatic pleural effusion (n = 5), small pneumothorax (n = 11), pneumothorax that necessitated chest tube placement (n = 4), and lung abscess (n = 1). No complications related to the specific tumor location, such as the accidental insertion of the electrode into the heart or aorta, pericardial effusion, arrhythmia, or cardiac infarction, occurred. The overall primary technique effectiveness rate was 75.8%, 45.9%, and 45.9% at 6, 12, and 24 months, respectively. This rate in group A (94.7%, 69.3%, and 69.3% at 6, 12, and 24 months, respectively) was significantly (P < .001) higher than that in group B (42.9% and 8.6% at 6 and 12 months, respectively).

CONCLUSIONS

Radiofrequency ablation of lung tumors close to the heart or aorta was safely performed. The local control of tumors contiguous to the heart or aorta was considerably lower compared with the tumors that were close but not contiguous to these structures.