Radiofrequency ablation of hepatocellular carcinoma guided by real-time physics-based ablation simulation: a prospective study.

OBJECTIVES: To assess the safety and efficacy of radiofrequency ablation (RFA) guidance software that incorporated patient-specific physics-based simulation of each ablation volume. MATERIALS AND METHODS: Patients referred for curative ablation of hepatocellular carcinoma (HCC) of 2-5 cm diameter were prospectively enrolled. RFA was performed under general anesthesia. Procedure planning and intraprocedural modifications were guided by computer simulation of each ablation. The segmented target (tumor with 5 mm margin) was registered to and superimposed on subsequent 3D multiplanar images. The applied RF energy was used to calculate a simulated ablation volume which was displayed relative to the electrode and segmented target, to depict any untreated target tissue. After each additional ablation, the software updated the accumulated simulated ablation volume in relation to the target. The primary endpoints were technical efficacy and rate of local tumor progression (LTP). RESULTS: Sixty-eight tumors were ablated during 57 procedures in 52 patients (68.3 ± 9.2 years old, 78.8% male); 15 (26.3%) had multiple lesions and 23 (39.1%) had prior HCC treatment. The mean tumor diameter was 2.73 (±0.64) cm. The intraprocedural simulation directed additional overlapping ablations in 75.9% of tumors. Technical success and efficacy were 100% at 3-month contrast enhanced CT or MRI follow-up after the single treatment session. Cumulative incidence function estimates for 1- and 2-year LTP were 3.9% and 20.2%, respectively. CONCLUSION: This prospective study found computer-assisted guidance that simulated each ablation was both safe and efficacious. The low rate of LTP was similar to studies that employed stereotactic guidance and ablation confirmation, without requiring a second contrast enhanced study.

Short-interval recanalization after gelfoam occlusion.

Gelfoam® is a temporary embolization agent often used in trauma where permanent arterial occlusion is not desired. Gelfoam occlusions have been shown to resolve by 2 weeks, but shorter intervals have not been studied. We report a case of spontaneous arterial hemorrhage due to ruptured hepatic malignancy where treatment was Gelfoam slurry occlusion of the right hepatic artery. Repeat hemorrhage resulted in repeat CT and hepatic arteriography, which showed that recanalization of the occluded artery had occurred in less than 48 hours. Gelfoam arterial occlusion in some cases may last less than 2 weeks.

Calciphylaxis: Comparison of radiologic imaging and histopathology.

BACKGROUND: The current gold standard for diagnosis of calciphylaxis is a skin biopsy specimen demonstrating calcification of small-caliber arteries or arterioles. OBJECTIVE: The aim of this study is to compare diameters of calcified vessels seen in skin biopsy specimens and radiology images of patients with calciphylaxis. METHODS: We conducted a retrospective study of patients with known calciphylaxis from 2009 to 2016 at a community hospital who had both skin biopsy specimens and radiology images taken as part of their routine care. Vascular calcification was compared in skin biopsy specimens and radiology images. RESULTS: Seven patients were identified. Small-vessel calcification as fine as 0.1 to 0.3 mm was identified on plain films in 3 patients; 0.1 to 0.2 mm by mammography in 3 patients, and 0.1 to 0.2 mm by computed tomography imaging in 1 patient, nearly as fine a resolution as on histopathology. LIMITATIONS: This was a single-center study with limited sample size. CONCLUSION: Radiologic imaging might enable more rapid diagnosis of calciphylaxis when skin biopsy specimen is pending or not available.