Increase in fluorodeoxyglucose positron emission tomography activity following complete radiofrequency ablation of lung tumors. J Comput Assist Tomogr. 2013;37:9-14. [PMID: 23321827 DOI: 10.1097/rct.0b013e3182732341]

Systematic Review of Image-Guided Thermal Ablation for Treatment of High-Risk Patients with Stage I Non-Small Cell Lung Cancer

Image-guided thermal ablation (IGTA) applied to pulmonary pathology is an alternative to surgery in high-risk patients with stage I non-small cell lung cancer (NSCLC). Its application to lung neoplasm was first introduced in 2001 and has been implemented to treat metastatic disease to the lung or in select medically inoperable patients with peripheral stage I NSCLC. IGTA may also be an alternative to treat stage I NSCLC in non-operable patients with interstitial lung disease in whom a radiation modality is deemed too high risk. There are 3 methods of delivery: radiofrequency ablation (RFA), microwave ablation and cryoablation. Observational series and some prospective trials have shown safety and efficacy across all three modalities. Despite accumulating experience, there are no large randomized clinical trials comparing the outcomes of lung IGTA to alternative locoregional therapies (eg, stereotactic body radiotherapy or sublobar pulmonary resection) for the treatment of stage I NSCLC. Because IGTA is a local therapy, a higher risk of locoregional recurrence is inherently understood as compared with anatomic resection. In the literature, primary tumor control after RFA ranges from 47 to 90% and is dependent on tumor size and proximity to bronchovascular structures. Local failure ranges from 10 to 47%, and tumors ≥3 cm have the highest rate of local recurrence. The most prevalent side effects are pneumothorax and reactive pleural effusion; hemorrhage is uncommon. Of note, observational series show no significant loss of lung function after IGTA. This expert review contextualizes limitations, complications and outcomes of IGTA in patients with stage I NSCLC.

A path toward the clinical translation of nano-based imaging contrast agents

Recently, nanoparticles have evolved ubiquitously in therapeutic applications to treat a range of diseases. Despite their regular use as therapeutic agents in the clinic, we have yet to see much progress in their clinical translation as diagnostic imaging agents. Several clinical and preclinical studies support their use as imaging contrast agents, but their use in the clinical setting has been limited to off-label imaging procedures (i.e., Feraheme). Since diagnostic imaging has been historically used as an exploratory tool to rule out disease or to screen patients for various cancers, nanoparticle toxicity remains a concern, especially when introducing exogenous contrast agents into a potentially healthy patient population, perhaps rationalizing why several nano-based therapeutic agents have been clinically translated before nano-based imaging agents. Another potential hindrance toward their clinical translation could be their market potential, as most therapeutic drugs have higher earning potential than small-molecule imaging contrast agents. With these considerations in mind, perhaps a clinical path forward for nano-based imaging contrast agents is to help guide/manage therapy. Several studies have demonstrated the ability of nanoparticles to produce more accurate imaging preoperatively, intraoperatively, and postoperatively. These applications illustrate a more reliable method of cancer detection and treatment that can prevent incomplete tumor resection and incorrect assessment of tumor progression following treatment. The aim of this review is to highlight the research that supports the use of nanoparticles in biomedical imaging applications and offer a new perspective to illustrate how nano-based imaging agents have the potential to better inform therapeutic decisions. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Follow-up after radiological intervention in oncology: ECIO-ESOI evidence and consensus-based recommendations for clinical practice

Interventional radiology plays an important and increasing role in cancer treatment. Follow-up is important to be able to assess treatment success and detect locoregional and distant recurrence and recommendations for follow-up are needed. At ECIO 2018, a joint ECIO-ESOI session was organized to establish follow-up recommendations for oncologic intervention in liver, renal, and lung cancer. Treatments included thermal ablation, TACE, and TARE. In total five topics were evaluated: ablation in colorectal liver metastases (CRLM), TARE in CRLM, TACE and TARE in HCC, ablation in renal cancer, and ablation in lung cancer. Evaluated modalities were FDG-PET-CT, CT, MRI, and (contrast-enhanced) ultrasound. Prior to the session, five experts were selected and performed a systematic review and presented statements, which were voted on in a telephone conference prior to the meeting by all panelists. These statements were presented and discussed at the ECIO-ESOI session at ECIO 2018. This paper presents the recommendations that followed from these initiatives. Based on expert opinions and the available evidence, follow-up schedules were proposed for liver cancer, renal cancer, and lung cancer. FDG-PET-CT, CT, and MRI are the recommended modalities, but one should beware of false-positive signs of residual tumor or recurrence due to inflammation early after the intervention. There is a need for prospective preferably multicenter studies to validate new techniques and new response criteria. This paper presents recommendations that can be used in clinical practice to perform the follow-up of patients with liver, lung, and renal cancer who were treated with interventional locoregional therapies.

Mechanism and non-mechanism based imaging biomarkers for assessing biological response to treatment in non-small cell lung cancer

Therapeutic options in locally advanced non-small cell lung cancer (NSCLC) have expanded in the past decade to include a palate of targeted interventions such as high dose targeted thermal ablations, radiotherapy and growing platform of antibody and small molecule therapies and immunotherapies. Although these therapies have varied mechanisms of action, they often induce changes in tumour architecture and microenvironment such that response is not always accompanied by early reduction in tumour mass, and evaluation by criteria other than size is needed to report more effectively on response. Functional imaging techniques, which probe the tumour and its microenvironment through novel positron emission tomography and magnetic resonance imaging techniques, offer more detailed insights into and quantitation of tumour response than is available on anatomical imaging alone. Use of these biomarkers, or other rational combinations as readouts of pathological response in NSCLC have potential to provide more accurate predictors of treatment outcomes. In this article, the robustness of the more commonly available positron emission tomography and magnetic resonance imaging biomarker indices is examined and the evidence for their application in NSCLC is reviewed.

Percutaneous ablation of colorectal lung metastases

Lung metastasectomy can prolong survival in patients with metastatic colorectal carcinoma. Thermal ablation offers a potential solution with similar reported survival outcomes. It has minimal effect on pulmonary function, or quality of life, can be repeated, and may be considered more acceptable to patients because of the associated shorter hospital stay and recovery. This review describes the indications, technique, reported outcomes, complications and radiologic appearances after thermal ablation of colorectal lung metastases.

Would you bet on PET? Evaluation of the significance of positive PET scan results post-microwave ablation for non-small cell lung cancer

Fluodeoxyglucose-positron emission tomography (FDG-PET) imaging is an acknowledged modality for the follow-up of solid tumours treated with thermal ablation, with persistent or new FDG uptake at the ablation site considered to be a reliable indicator of local recurrence. Several cases of proven false-positive FDG-PET scans are illustrated in this pictorial essay with uptake at the site of the ablated tumour, remote from the ablated lesion and in mediastinal and hilar lymph nodes. Positive FDG-PET scans post-thermal ablation of lung tumours therefore cannot always reliably predict local tumour recurrence or nodal spread. It is important to be familiar with FDG uptake patterns post-ablation and their significance. FDG-PET avid lesions post-ablation may require histological confirmation before further therapy is planned or management is changed.

Thermal ablation of stage I non-small cell lung carcinoma

Ablation options for the treatment of localized non-small cell lung carcinoma (NSCLC) include radiofrequency ablation, microwave ablation, and cryotherapy. Irreversible electroporation is a novel ablation method with the potential of application to lung tumors in risky locations. This review article describes the established and novel ablation techniques used in the treatment of localized NSCLC, including mechanism of action, indications, potential complications, clinical outcomes, postablation surveillance, and use in combination with other therapies.

The Role of PET Imaging Before, During, and After Percutaneous Hepatic and Pulmonary Tumor Ablation

The combination of anatomic and metabolic information provided by positron emission tomography (PET)/computed tomography makes it an important imaging modality to be obtained in conjunction with percutaneous ablation of primary and secondary malignancies of the lungs and liver. Advantages include more accurate preprocedural staging to determine appropriate treatment options, intraprocedural guidance to target difficult-to-see lesions, and postprocedural detection of residual or recurrent disease. Future applications of PET include strategies for intraprocedural guidance with real-time determination of incompletely ablated tumor, and combined PET/magnetic resonance imaging before, during, and after ablation for greater sensitivity to detect disease.

Radiofrequency ablation as treatment for pulmonary metastasis of colorectal cancer

Radiofrequency ablation (RFA) causes focal coagulation necrosis in tissue. Its first clinical application was reported in 2000, and RFA has since been commonly used in both primary and metastatic lung cancer. The procedure is typically performed using computed tomography guidance, and the techniques for introducing the electrode to the tumor are simple and resemble those used in percutaneous lung biopsy. The most common complication is pneumothorax, which occurs in up to 50% of procedures; chest tube placement for pneumothorax is required in up to 25% of procedures. Other severe complications, such as pleural effusion requiring chest tube placement, infection, and nerve injury, are rare. The local efficacy depends on tumor size, and local progression after RFA is not rare, occurring in 10% or more of patients. The local progression rate is particularly high for tumors > 3 cm. Repeat RFA may be used to treat local progression. Short- to mid-term survival after RFA appears promising and is approximately 85%-95% at 1 year and 45%-55% at 3 years. Long-term survival data are sparse. Better survival may be expected for patients with small metastasis, low carcinoembryonic antigen levels, and/or no extrapulmonary metastasis. The notable advantages of RFA are that it is simple and minimally invasive; preserves pulmonary function; can be repeated; and is applicable regardless of previous treatments. Its most substantial limitation is limited local efficacy. Although surgery is still the method of choice for treatment with curative intent, the ultimate application of RFA may be to replace metastasectomy for small metastases. Randomized trials comparing RFA with surgery are needed.