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.

Image-guided biopsy in the age of personalised medicine: strategies for success and safety.

Oncology has progressed into an era of personalised medicine, whereby the therapeutic regimen is tailored to the molecular profile of the patient's cancer. Determining personalised therapeutic options is achieved by using tumour genomics and proteomics to identify the specific molecular targets against which candidate drugs can interact. Several dozen targeted drugs, many for multiple cancer types are already widely in clinical use. Molecular profiling of tumours is contingent on high-quality biopsy specimens and the most common method of tissue sampling is image-guided biopsy. Thus, for radiologists performing these biopsies, the paradigm has now shifted away from obtaining specimens simply for histopathological diagnosis to acquiring larger amounts of viable tumour cells for DNA, RNA, or protein analysis. These developments have highlighted the central role now played by radiologists in the delivery of personalised cancer care. This review describes the principles of molecular profiling assays and biopsy techniques for optimising yield, and describes a scoring system to assist in patient selection for percutaneous biopsy.

The value of interventional radiology in clinical trial teams: experience from the BATTLE lung cancer trials.

AIM: To report on the multidisciplinary approach, focusing specifically on the role of the interventional radiologist (IR), used to support the Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) and BATTLE-2 trials. MATERIALS AND METHODS: Patients who underwent percutaneous image-guided biopsy for the BATTLE and BATTLE-2 trials were reviewed. A radiology-based, three-point, lesion-scoring system was developed and used by two IRs. Lesions were given a score of 3 (most likely to yield sufficient material for biomarker analysis) if they met the following criteria: size >2 cm, solid mass, demonstrated imaging evidence of viability, and were technically easy to sample. Lesions not meeting all four criteria were scored 2 with the missing criteria noted as negative factors. Lesions considered to have risks that outweighed potential benefits receive a score of 1 and were not biopsied. Univariate and multivariate analyses were performed to evaluate the score's ability to predict successful yield for biomarker adequacy. RESULTS: A total of 555 biopsies were performed. The overall yield for analysis of the required biomarkers was 86.1% (478/555), and 84% (268/319) and 88.9% (210/236) for BATTLE and BATTLE-2, respectively (p=0.09). Lesions receiving a score of 3 were adequate for biomarker analysis in 89% of cases. Lesions receiving a score of 2 with more than two negative factors were adequate for molecular analysis in 69.2% (IR1, p=0.03) and 74% (IR2, p=0.04) of cases. The two IRs scored 78.4% of the lesions the same indicating moderate agreement (kappa=0.55; 95% confidence interval [CI]: 0.48, 0.61). CONCLUSIONS: IRs add value to clinical trial teams by optimising lesions selected for biopsy and biomarker analysis.