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

Imaging of the thorax after percutaneous thermal ablation of lung malignancies

Image-guided thermal ablation is a minimally invasive treatment option for patients with early stage non-small cell lung cancer or metastatic disease to the lungs. Percutaneous ablation treats malignant tumours in situ, which precludes histopathological evaluation of the ablated tumours. Imaging studies are used as surrogates to assess technical and clinical success. Although it is not universally accepted, a common protocol for surveillance imaging includes contrast-enhanced computed tomography (CT) at 1, 3, 6, 9, 12, 18, 24 months, and yearly thereafter. Integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose positron-emission tomography (PET)/CT imaging is recommended at 3 and 12 months and when recurrent disease is suspected. There is a complex evolution of the ablation zone on CT and PET imaging studies. The zone of ablation, initially larger than the ablated tumour, undergoes gradual involution. In the process, it may cavitate and resemble a lung abscess. Different contrast-enhancement and radionuclide uptake patterns in and around the ablation zone may indicate a wide range of diagnostic possibilities from a normal physiological response to local progression. Ultimately, the zone of ablation may be replaced by a variety of findings including linear bands of density, pleural thickening, or residual necrotic tumour. Diagnostic and interventional radiologists interpreting post-ablation imaging studies must have a clear understanding of the ablation process and imaging findings on surveillance studies. Accurate and timely recognition of complications and/or local recurrence is necessary to guide further therapy. The purpose of this article is to review imaging protocols and salient imaging findings after thermal ablation of lung malignancies.

Percutaneous radiofrequency ablation in the treatment of pulmonary malignancies: efficacy, safety and predictive factors

Purpose

The purpose of this study was to evaluate the efficacy, safety and predictive factors of RFA of primary and secondary lung malignancies.

Patients and Methods

79 patients with 129 primary and secondary lung malignancies were enrolled in a retrospective study. We treated 74 pulmonary metastases of colorectal cancer, 13 malignant melanoma lesions, 13 renal cancer metastases, 5 primary lung malignancies and 24 tumors of other different entities. All patients were considered to be unsuitable candidates for surgery, radiotherapy or chemotherapy. The primary endpoint was local tumor control, secondary endpoints were overall survival, safety and predictive factors, e.g. distance to pleura, vessels and bronchi.

Results

The median tumor size was 1.2 cm (0.5–3.0 cm). After a median follow-up of 14 months (3–81 months), the LTC was 85.3 %. There were 34 lesions (26.4%) with complete remission, 48 (37.2 %) partial remission, 28 (21.7%) stable disease and 19 lesions (14.7%) with progressive disease. We evaluated an OS of 27 months. Pneumothorax in 19 cases (14.7%) and pleural effusion in 2 cases (1.6 %) were the leading complications (CTCAE, 5 grade III adverse events). The only significant influence regarding the outcome after RFA was the initial tumor size (p = 0.01). Distance to vessel, bronchi, and pleura showed no significant effect (p = 0.81; p = 0.82; p = 0.80).

Lung Ablation: Whats New?

Lung cancer had an estimated incidence of 221,200 in 2015, making up 13% of all cancer diagnoses. Tumor ablation is an important treatment option for nonsurgical lung cancer and pulmonary metastatic patients. Radiofrequency ablation has been used for over a decade with newer modalities, microwave ablation, cryoablation, and irreversible electroporation presenting as additional and possibly improved treatment options for patients. This minimally invasive therapy is best for small primary lesions or favorably located metastatic tumors. These technologies can offer palliation and sometimes cure of thoracic malignancies. This article discusses the current available technologies and techniques available for tumor ablation.

From diagnosis to therapy in lung cancer: management of CT detected pulmonary nodules, a summary of the 2015 Chinese-German Lung Cancer Expert Panel

The first Chinese-German Lung Cancer Expert Panel was held in November 2015 one day after the 7th Chinese-German Lung Cancer Forum, Shanghai. The intention of the meeting was to discuss strategies for the diagnosis and treatment of lung cancer within the context of lung cancer screening. Improved risk classification criteria and novel imaging approaches for screening populations are highly required as more than half of lung cancer cases are false positive during the initial screening round if the National Lung Screening Trial (NLST) demographic criteria [≥30 pack years (PY) of cigarettes, age ≥55 years] are applied. Moreover, if the NLST criteria are applied to the Chinese population a high number of lung cancer patients are not diagnosed due to non-smoking related risk factors in China. The primary goal in the evaluation of pulmonary nodules (PN) is to determine whether they are malignant or benign. Volumetric based screening concepts such as investigated in the Dutch-Belgian randomized lung cancer screening trial (NELSON) seem to achieve higher specificity. Chest CT is the best imaging technique to identify the origin and location of the nodule since 20% of suspected PN found on chest X-ray turn out to be non-pulmonary lesions. Moreover, novel state-of-the-art CT systems can reduce the radiation dose for lung cancer screening acquisitions down to a level of 0.1 mSv with improved image quality to novel reconstruction techniques and thus reduce concerns related to chest CT as the primary screening technology. The aim of the first part of this manuscript was to summarize the current status of novel diagnostic techniques used for lung cancer screening and minimally invasive treatment techniques for progressive PNs that were discussed during the first Chinese-German Lung Cancer. This part should serve as an educational part for the readership of the techniques that were discussed during the Expert Panel. The second part summarizes the consensus recommendations that were interdisciplinary discussed by the Expert Panel.

FDG-PET in the evaluation of response to nivolumab in recurrent non-small-cell lung cancer

BACKGROUND

Nivolumab, an immune checkpoint inhibitor, is recently clinically applied to non-small cell lung cancer (NSCLC) treatment, and this causes T cell activation and T cell infiltration to tumor tissue through the blockade of the interaction between programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1). 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) sometimes shows false positive because of the recruitment of neutrophils, lymphocytes, and macrophages. To date, there is only one report except our case, which described the correlation between FDG-PET and nivolumab.

CASE PRESENTATION

We report on a 75-year-old man on nivolumab treatment for metastatic non-small cell lung cancer. He had undergone right lower lobectomy for lung adenocarcinoma in the right S8 segment 10 months prior to recurrence. Pathological findings revealed invasive adenocarcinoma, pT1bN2M0 stage IIIA. Epidermal growth factor receptor (EGFR) mutation was positive for de novo T790M and anaplastic lymphoma kinase (ALK) rearrangement was negative. Immunohistochemistry was negative for PD-L1. He underwent chemotherapy with a combination of cisplatin and pemetrexed for four cycles but developed progressive disease involving the right hemithorax, multiple lymph nodes, and multiple osseous sites. Nivolumab was instituted as a second-line chemotherapy. After six courses of this immunotherapy, FDG-PET scan showed decreased FDG uptake in each recurrent lesion despite T lymphocyte activation by nivolumab. Serum carcinoembryonic antigen (CEA) level was also remarkably decreased.

CONCLUSIONS

Nivolumab's effect on recurrent NSCLC may be monitored by PET; larger studies are needed.

Ablative Approaches for Pulmonary Metastases

Pulmonary metastases are common in patients with cancer for which surgery is considered a standard approach in appropriately selected patients. A number of patients are not candidates for surgery due to a medical comorbidities or the extent of surgery required. For these patients, noninvasive or minimally invasive approaches to ablate pulmonary metastases are potential treatment strategies. This article summarizes the rationale and outcomes for non-surgical treatment approaches, including radiotherapy, radiofrequency and microwave ablation, for pulmonary metastases.

Role of PET/Computed Tomography in Radiofrequency Ablation for Malignant Pulmonary Tumors

Radiofrequency ablation (RFA) is a useful tool for local control of unresectable pulmonary neoplastic lesions. However, RFA is limited to tumors smaller than 4 cm and peripheral lesions. The sensitivity and specificity of FDG-PET are higher than those of computed tomography. FDG-PET at 3 to 6 months after RFA is important for predicting recurrence. Complications associated with RFA, such as infection and abscess formation, which concentrate glucose in the ablation area, can cause false-positive findings in PET examination. Knowledge of the morphologic imaging features of these complications is important in avoiding these potential pitfalls.

Current readings: Percutaneous ablation for pulmonary metastatic disease

Percutaneous image-guided ablation is a technique for maintaining local control of metastatic lung lesions that may, in selected patients, confer a survival benefit over no treatment or systemic therapy alone. Although the currently accepted treatment for oligometastatic pulmonary disease is surgical resection, the existing body of literature, including the recent investigations reviewed within this article, supports a role for percutaneous ablation as an important and relatively safe therapeutic option for nonsurgical and in carefully selected surgical patients, conferring survival benefits competitive with surgical metastasectomy. Continued clinical investigations are needed to further understand the nuances of thermal technologies and applications to treat lung primary and secondary pulmonary malignancy, directly compare available therapeutic options and further define the role of percutaneous image-guided ablation in the treatment of pulmonary metastatic disease.