Radiofrequency ablation (RFA) is used to treat inoperable tumors or to treat patients ineligible for surgery due to age, presence of comorbidities, or poor general health. Goal(s) of RFA may include:

 

The procedure kills cells (cancerous and normal) by applying a heat-generating rapidly alternating current through probes inserted into the tumor. The effective volume of RFA depends on the frequency and duration of applied current, local tissue characteristics, and probe configuration (e.g., single versus multiple tips). RFA can be performed as an open surgical procedure, laparoscopically, or percutaneously with ultrasound or computed tomography (CT) guidance.

 

Potential complications associated with RFA include those caused by heat damage to normal tissue adjacent to the tumor (e.g., intestinal damage during RFA of kidney), structural damage along the probe track (e.g., pneumothorax as a consequence of procedures on the lung), or secondary tumors if cells seed during probe removal.

 

RFA was developed initially to treat inoperable tumors of the liver . Recently, reports have been published on use of RFA to treat renal cell carcinomas, breast cancer, pulmonary (primary lung cancers or metastatic tumors), bone, and other tumors. For some of these, RFA is being investigated as an alternative to surgery for operable tumors. Well-established local or systemic treatment alternatives are available for each of these malignancies. The hypothesized advantages of RFA for these cancers include improved local control and those common to any minimally invasive procedure (preserving normal organ tissue, decreasing morbidity, decreasing length of hospitalization, etc).

 

Primary lung cancers are resected if they are small, solitary masses. Adjuvant radiation and chemotherapy usually are added, most often using a platinum compound combined with one or more other drug such as a taxane, alkylating agent, vinca alkaloid, or topoisomerase inhibitor. The preferred regimen depends on histologic type. Patients with metastatic pulmonary lesions are also treated with chemotherapy, but with palliative intent or to relieve symptoms. Surgical resection of isolated metastatic lung lesions is an option, but is not used very often due to generally poor patient health, inoperability of most metastatic lesions, and lack of evidence for benefit to patients.

 

 

 

 

 

 

 

 

 

 

 

Radiofrequency ablation as a technique for ablating tumors of the lung, either primary or metastatic tumors does not meet member benefit certificate primary coverage criteria.  The effectiveness of radiofrequency ablation is being studied in clinical trials.

 

For contracts without primary coverage criteria, radiofrequency ablation as a technique for ablating tumors of the lung, either primary or metastatic tumors is considered investigational.  Investigational services are an exclusion in the member certificate of coverage.

This policy is based on an analysis of relevant literature identified in a MEDLINE/PubMed search performed in June 2003.   Most of the identified studies were uncontrolled, retrospective case series or case reports.  Furthermore, the reviewed studies generally reported only immediate or short-term effects of RFA that did not permit conclusions regarding the net health benefit of RFA for patients with these tumors.

 

One study reported use of RFA in 10 patients with sarcomas and primary lung cancers and 8 patients with metastatic tumors in the lung. All patients had potentially resectable disease after failing previous nonoperative treatment, but were not considered surgical candidates because of  "poor physiological reserve or patient refusal.” With mean follow-up of 6 months, RFA fully ablated tumors in 66% (8 of 12) of patients with tumors smaller than 5 cm, compared with 33% in larger tumors (2 of 6). Complications were common, including 1 fatality from massive hemoptysis and 1 case of transient acute respiratory failure. Nonfatal complications included pleural effusion in 50%, pneumothorax in 54% (all CT-guided group), thoracocentesis in 11%, and pneumonia/pneumonitis in 22%.

 

VanSonnenberg and colleagues reported the use of RFA in 30 patients with a spectrum of primary  and secondary  lung tumors, mesothelioma , and 5 secondarily eroded, painful ribs who underwent ablation for 36 total lesions (VanSonnenberg, 2005).  Patients were not considered surgical candidates because they had medical comorbidities or extensive disease; they had exhausted chemotherapy and radiotherapy options; or they had “refused” surgery or undergone “unsuccessful” surgery. All ablations were deemed “technically successful.” Contrast-enhanced CT or enhanced magnetic resonance imaging (MRI) studies demonstrated necrosis of 90% or better in 26 of 29 (89.7%) patients with lung lesions; pain was ameliorated in 11 of 11 (100%) patients who reported painful lesions. The longest follow-up without recurrence was 26 months. Complications included hemoptysis, pneumothorax, atrial fibrillation, respiratory difficulty, hoarseness, and a small third-degree skin burn in 1 case. Post-procedure FDG-PET showed loss of virtually all FDG activity in 9 of 10 (90%) previously positive tumors that were examined with this technology.

 

A number of small case series or uncontrolled cohort studies were identified  which focused primarily on technical feasibility and initial tumor response. Study quality concerns include lack of long-term follow-up; significant interstudy heterogeneity in terms of study design, patient populations, and RFA methods used; and non-uniformity of reporting and efficacy scoring criteria.

 

One retrospective study reported long-term (up to 5 years of follow-up) efficacy and safety of RFA in 153 patients with primary or metastatic pulmonary cancers (Simon, 2007).  A 5-year survival rate of 27% for RFA in stage Ia or b non-small cell lung cancer and 57% for metastatic colorectal cancer lesions suggests this technique holds promise for treatment of non-resectable pulmonary lesions. However, these results are compromised by the retrospective nature of the data; the potential confounding effects of undefined prior and adjuvant chemo- or radiotherapy; lack of histopathologic proof of treatment completeness; substantial patient and disease heterogeneity; and failure to separate overall survival rates according to disease. Other case series were reported for RFA of primary and metastatic pulmonary lesions, but none provide convincing evidence for its efficacy.

 

A prospective, single-arm, multicenter trial from 7 centers in Europe, the U.S., and Australia reported the technical success, safety, response of tumors, and survival in 106 patients with 183 lung tumors (Lencioni, 2008).  All patients were considered to be unsuitable for surgery and unfit for radiotherapy or chemotherapy. Tumors measured less than 3.5 cm and included patients with NSCLC (n=22), colorectal metastases (n=41) and other metastases (n=16). Technical success rate was 99%. Patients were followed for 2 years, and a confirmed complete response lasting at least a year was observed in 88% of assessable patients, with no differences in response rate between patients with primary and metastatic tumors. Overall survival in patients with NSCLC was 70% at 1 year  and 48% at 2 years. Overall survival in patients with metastatic colorectal cancer was 89% at one year and 66% at 2 years . Overall survival in patients with other metastases was 92% at one year and 64% at 2 years.  Patients with stage 1 NSCLC (n=13) had overall survival rates of 75%  at 2 years. Comparison of patient survival rates with those from other studies in which different modalities were used are unreliable due to the heterogeneity of the study population and the severe pulmonary impairment and significant comorbidities of the patients in this study.

 

A systematic review of RFA for primary and secondary lung tumors included studies that reported procedure-related morbidity and mortality, rates of complete tumor ablation, local recurrence and/or overall survival (Zhu, 2008).  Seventeen studies were included for a total of 707 patients, and all were observational case series with no control groups, and were classified as poor quality by the authors of the systematic review. No randomized, controlled trials or comparative studies were found. The definition of nonsurgical candidates differed from study to study, and there were differences in the criteria used for tumor resectability. An additional confounding factor was that in some studies, additional therapies were used with RFA, such as systemic chemotherapy.  The authors of the systematic review concluded that there is limited evidence reporting clinical outcomes of RFA treatment of lung tumors, and that the evidence is relatively low, with no randomized, controlled trials or case-control trials comparing the use of RFA with conventional treatment for nonsurgical patients. Of the studies that they included in their review, there were a wide range in results of local recurrence rates, heterogeneity of the patients selected and tumor characteristics, and relatively short follow-up in most.

 

In summary, the data are insufficient to permit conclusions on net health outcomes of the use of RFA in the treatment of lung tumors.

 

NCCN practice guidelines state that recent studies suggest that RFA may be an option for node-negative patients who either refuse surgery or cannot tolerate surgery, and that optimal candidates for RFA include patients with an isolated peripheral lesion less than 3 cm.

 

A phase 2 pilot study of RFA in high-risk patients with stage 1a NSCLC (NCT00109876) was identified. An additional study is ongoing (no phase specified) assessing short and long term outcomes after RFA of pulmonary malignancies in patients who are not candidates for surgical resection (NCT00280189). Parameters to be evaluated include efficacy, local tumor control, progression-free survival, overall survival, and quality of life.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

A literature search conducted through January 2017 did not reveal any new information that would prompt a change in the coverage statement.