Radiofrequency ablation of primary and metastatic lung cancers

Radiofrequency versus microwave ablation for treatment of the lung tumours: LUMIRA (lung microwave radiofrequency) randomized trial

The LUMIRA trial evaluated the effectiveness of radiofrequency (RFA) and microwave ablation (MWA) in lung tumours ablation and defining more precisely their fields of application. It is a controlled prospective multi-centre random trial with 1:1 randomization. Fifty-two patients in stage IV disease (15 females and 37 males, mean age 69 y.o., range 40-87) were included. We randomized the patients in two different subgroups: MWA group and RFA group. For each group, we evaluated the technical and clinical success, the overall survival and complication rate. Inter-group difference was compared using Chi-square test or Fisher's exact test for categorical variables and one-way ANOVA test for continuous variables. For RFA group, there was a significant reduction in tumour size only between 6 and 12 months (p value = 0.0014). For MWA group, there was a significant reduction in tumour size between 6 and 12 months (p value = 0.0003) and between pre-therapy and 12 months (p value = 0.0215). There were not significant differences between the two groups in terms of survival time (p value = 0.883), while the pain level in MWA group was significantly less than in RFA group (1.79 < 3.25, p value = 0.0043). In conclusion, our trial confirms RFA and MWA are both excellent choices in terms of efficacy and safety in lung tumour treatments. However, when compared to RFA therapy, MWA produced a less intraprocedural pain and a significant reduction in tumour mass.

Pulmonary radiofrequency ablation (Part 1): current state

The risks involved in surgical treatment and conventional radiotherapy in patients with early lung cancer or lung metastases often make these treatments difficult to justify. However, on the other hand, it is also unacceptable to allow these lesions to evolve freely because, left untreated, these neoplasms will usually lead to the death of the patient. In recent years, alternative local therapies have been developed, such as pulmonary radiofrequency ablation, which has proven to increase survival with a minimal risk of complications. There are common recommendations for these treatments, and although the specific indications for using one technique or another have yet to be established, there are clearly defined situations that will determine the outcome of the treatment. It is important to know these situations, because appropriate patient selection is essential for therapeutic success. This article aims to describe the characteristics and constraints of pulmonary radiofrequency ablation and to outline its role in thoracic oncology in light of the current evidence.

A phase II study of radiofrequency ablation therapy for thoracic malignancies with evaluation by FDG-PET

PURPOSE

Computed tomography (CT)-guided radiofrequency ablation (RFA) is safe and effective for patients with unresectable primary, recurrent, or metastatic thoracic malignancies. Several studies have shown the benefit of employing 18-fluoro-deoxyglucose positron-emission tomography (FDG-PET) to follow thoracic malignancies treated with RFA. In this prospective study, we show the safety and therapeutic efficacy of RFA and the utility of FDG-PET as tool for early detection of local recurrence.

METHODS

Twenty patients were enrolled in this study, and 24 lesions were ablated. Seven lesions were primary lung cancer, and 17 lesions were recurrent tumors or metastases from extrathoracic sites. Tumor size was in the range of 0.4-3.3 cm in diameter (mean: 1.5 cm). CT and FDG-PET scans were scheduled 7-14 days and 3-6 months after RFA treatment.

RESULTS

There were 17 adverse events (70.8 %) in 24 ablations included 13 pneumothoraces, two cases of chest pain, and two episodes of fever. With a median follow-up of 35.9 months (range 1-62 months), the overall 2-year survival rate was 84.2 %. Local recurrence occurred at four sites (2-year local control rate was 74.3 %). The FDG-PET results 7-14 days after RFA did not predict recurrence, whereas positive findings 3-6 months after RFA significantly correlated with local recurrence (p = 0.0016).

CONCLUSIONS

We confirmed the effectiveness of RFA for unresectable primary and secondary thoracic malignancies. FDG-PET analysis 3-6 months after ablation is a useful tool to assess local control.

Ki 67 is an independent predictive biomarker of cancer specific and local recurrence-free survival after lung tumor ablation

BACKGROUND

The objective of this work was to evaluate the feasibility of histopathological analysis of tissue extracted on multitined electrodes and assess whether tissue characteristics can be used as biomarkers of oncologic outcomes after lung tumor radiofrequency (RF) ablation.

METHODS

Treatment-related data regarding RF ablation of lung malignancies at our institution was collected using a Health Insurance Portability and Accountability Act-compliant ablation database. Institutional review board waiver was obtained for this study. Immunohistochemical analysis of tissue extracted from the electrodes after lung tumor RF ablation was performed for proliferation (Ki-67) and apoptosis (caspase-3). Patient, tumor demographics, and ablation parameters were recorded. Local tumor progression-free survival (LPFS), disease-specific survival (DSS), and overall survival (OS) were assessed using Kaplan-Meier methodology. Multivariate analysis determined factors affecting these oncological outcomes.

RESULTS

A total of 47 lung tumors in 42 patients were ablated; 30 specimens were classified as coagulation necrosis (CN) and 17 as Ki-67-positive (+) tumor cells (viable). Tumor sizes were similar in the CN and Ki-67+ groups (P = 0.32). Median LPFS was 10 versus 16 months for Ki-67+ and CN groups, and 1-year LPFS was 34 and 75 %, respectively (P = 0.003). Median OS was 20 and 46 months (P = 0.12), and median DSS was 20 and 68 months (P = 0.01) for the Ki-67 + and CN groups, respectively. Identification of Ki-67+ tumor cells more than tripled the risk of death from cancer [hazard ratio (HR) = 3.65; 95 % confidence interval (95 % CI), 1.34-9.95; P = 0.01] and tripled the risk of local tumor progression (LTP) (HR = 3.01; 95 % CI, 1.39-6.49; P = 0.005).

CONCLUSIONS

Ki-67+ tumor cells on the electrode after pulmonary tumor RF ablation is an independent predictor of LTP, shorter LPFS, and DSS.

Microwave ablation treatment of liver cancer with a 2,450-MHz cooled-shaft antenna: pilot study on safety and efficacy

To evaluate efficacy of microwave ablation in a primary clinical study, sixty patients (44 men, 16 women; mean age 53 years) with 96, 1-8 cm (mean 3.20 ± 0.17 cm) liver cancers were treated with 2,450-MHz internally cooled-shaft antenna. Complete ablation (CA) and local tumor progression (LTP) rates as well as complications were determined. CA rates in small (<3.0 cm), intermediate (3.1-5.0 cm) and large (5.1-8.0 cm) liver cancers were 96.4% (54/56), 92.3% (24/26) and 78.6% (11/14), respectively. During a mean follow-up period of 17.17 ∓ 6.52 months, LTP occurred in five (5.21%) treated cases. There was no significant difference in the CA and LTP rates between the HCC and liver metastasis patient subgroups (P<0.05). Microwave ablation provides a reliable, efficient, and safe technique to perform hepatic tumor ablation.

[Radiofrequency ablation for the treatment of lung neoplasms: a retrospective study of 329 cases]

背景与目的

射频消融（radiofrequency ablation, RFA）是近年来用于无法手术的肺部恶性肿瘤及肺转移瘤治疗的替代方案。本研究旨在评估肺射频消融术的安全性和临床疗效。

方法

本研究回顾性分析1999年10月-2006年7月在第四军医大学唐都医院胸腔外科进行肺部恶性肿瘤射频消融术的患者329例（其中肺部原发肿瘤237例，转移瘤92例），对其进行射频治疗后的并发症、局部进展以及1年、2年和5年总生存期的临床资料进行了研究及评价分析。

结果

行射频手术的患者术后出现的并发症包括：气胸63例（19.1%），咯血14例（死亡1例，4.2%），血胸10例（3.0%），肺炎15例（4.5%）和心包填塞3例（死亡1例，0.9%），术后30天内的死亡率为0.6%，针道肿瘤种植的患者6例（1.8%）。中位无进展时间为21.6个月。1年、2年和5年总生存率分别为68.2%、35.3%和20.1%。共有78例（23.7%）患者出现后期肿瘤局部进展。肺部肿瘤原位局部进展的患者的肿瘤包块直径大多 > 4 cm; 在肿瘤局部进展方面，肿瘤 < 3 cm的患者与直径介于3 cm-4 cm的肿瘤患者相比没有明显差异，这两组患者与直径 > 4 cm的肿瘤患者间存在明显差异。

结论

对于肺部恶性肿瘤来说，射频治疗是一种耐受性良好、疗效可靠安全的治疗方法。

Ablation of pulmonary malignancy: current status

Since the first reported use of radiofrequency ablation of the lung in 2000, the field of image-guided lung ablation has received a considerable amount of attention. Survival studies have demonstrated the potential utility of thermal ablation in the treatment of patients with early-stage primary and limited secondary pulmonary tumors with promising results. Diagnostic imaging studies have advanced the understanding of the expected immediate postablation appearance of treated lesions, leading the way for early detection of local tumor progression. These survival studies and the expected imaging follow-up of these patients are reviewed herein.

18F-FDG PET/CT for the prediction and detection of local recurrence after radiofrequency ablation of malignant lung lesions

The utility of (18)F-FDG PET/CT for response assessment in malignant lung tumors treated with radiofrequency ablation (RFA) and for the detection and prediction of local recurrence was investigated.

METHODS

Between December 17, 2003, and April 9, 2008, 68 consecutive patients (mean age, 68 y) with 94 pulmonary lesions, including metastases (n = 38) and primary lung cancers (n = 44), underwent RFA. Because of inadequate imaging follow-up in 12 patients, only 82 lesions were analyzed (CT scans, n = 82; (18)F-FDG PET/CT scans, n = 62). The median follow-up was 25 mo (range, 12-66 mo). A baseline study was defined as (18)F-FDG PET/CT performed no more than 3 mo before RFA. The first postablation scan was defined as PET/CT performed between 1 and 4 mo after RFA; additional follow-up studies were obtained in some cases between 6 and 12 mo after RFA. The unidimensional maximum diameter of the lesion was recorded on a pretherapy diagnostic CT scan or on the CT component of a pretherapy (18)F-FDG PET/CT scan, whichever was obtained most recently, using lung windows. Maximum standardized uptake values (SUVs) were recorded for all lesions imaged by (18)F-FDG PET/CT. (18)F-FDG uptake patterns on post-RFA scans were classified as favorable or unfavorable. Survival and recurrence probabilities were estimated using the Kaplan-Meier method. Uni- and multivariate analyses were also performed.

RESULTS

Before RFA, factors predicting greater local recurrence-free survival included initial lesion size less than 3 cm (P = 0.01) and SUV less than 8 (P = 0.02), although the latter was not an independent predictor in multivariate analysis. Treated metastases recurred less often than treated primary lung cancers (P = 0.03). Important post-RFA factors that related to reduced recurrence-free survival included an unfavorable uptake pattern (P < 0.01), post-RFA SUV (P < 0.01), and an increase in SUV over time after ablation (P = 0.05).

CONCLUSION

(18)F-FDG PET/CT parameters on both preablation and postablation scans may predict local recurrence in patients treated with RFA for lung metastases and primary lung cancers.

Microwave ablation treatment of liver cancer with 2,450-MHz cooled-shaft antenna: an experimental and clinical study

PURPOSE

To evaluate effects of microwave ablation with a 2,450-MHz internally cooled-shaft antenna in animal experiments and in a clinical study.

METHODS

Microwave ablation was performed using a cooled-shaft antenna in eight in vivo (36 ablations) porcine livers. The coagulation diameters achieved in different microwave ablation parameter groups were compared. Sixty patients (44 men, 16 women; mean age 53 years) with 96, 1-8 cm (mean 3.20 +/- 0.17 cm) liver cancers were treated with the same microwave ablation technique. Complete ablation (CA), local tumor progression (LTP) rates and complications were determined.

RESULTS

In vivo livers, short axis diameter correlated with the coagulation duration in a sigmoidal curve fashion (60-W group R(2) = 0.76, 80-W group R(2) = 0.87), with a relative plateau achieved within 10 min for power settings of 60 or 80 W. Within 10 min in the 60 and 80-W groups, respectively, 89 and 85.76% of maximum short axis diameter were achieved. CA rates in small (3.0 cm), intermediate (3.1-5.0 cm) and large (5.1-8.0 cm) liver cancers were 96.43% (54/56), 92.31% (24/26) and 78.57% (11/14), respectively. During a mean follow-up period of 17.17 +/- 6.52 months, LTP occurred in five (5.21%) treated cancers. There was no significant difference in the CA and LTP rate between the HCC and liver metastasis patient subgroups (P > 0.05).

CONCLUSIONS

The short axis diameter enlargement has a relative plateau within 10 min by fixing power output to 60 or 80 W, using the 2,450-MHz internally cooled-shaft antenna in vivo porcine livers. Effective local tumor control was achieved during one microwave ablation session.