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

A Multimodal Approach to Evaluate for Cardiac Metastasis in a Case of Non-Small Cell Lung Cancer

Malignancies have demonstrated the ability to metastasize to cardiac tissue. However, an optimal diagnostic algorithm for cardiac tumors has not yet been established, due at least in part to the scarcity of symptomatic cases. Several case reports describe how the usage of ¹⁸F-labeled fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) incidentally revealed cardiac neoplasia. This modality, which indicates uptake sites of the radioisotope ¹⁸F-FDG, allows for whole-body imaging and is often used for preoperative determination of malignant metastasis or for assessing response to therapy over time. However, findings of false positivity are often reported due to increased FDG avidity caused by a range of other, nonmetastatic processes, most notably inflammation and infection. In this case report, an 84-year-old male with stage IV non-small cell lung cancer presented a clinical course, echocardiogram, and ¹⁸F-FDG PET-CT findings that were suggestive of endocardial metastasis. Nine months into therapy, after extensive consultation, the patient finally consented to a more complete workup using cardiac MRI (CMRI), which showed no evidence of cardiac metastasis. This case report supports the utility of CMRI as a means of further interpreting intracardiac, localized FDG uptake foci in PET-CT findings, in order to avoid false positivity and further refine proposed cardiac differential diagnoses in cancer patients.

Cryoablation of Lung Metastases: Review of Recent Literature and Ablation Technique

This article reviews the current indications for image-guided thermal ablation of pulmonary metastatic disease. It also summarizes data regarding the efficacy and complications of lung cryoablation and present techniques for performing lung cryoablation as informed by the recent literature.

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.