Percutaneous ablation is an accepted treatment modality for primary hepatocellular carcinoma (HCC) and liver metastases. The goal of curative ablation is to cause the necrosis of all tumour cells with an adequate margin, akin to surgical resection, while minimising local damage to non-target tissue. Aside from the ablative modality, the proceduralist must decide the most appropriate imaging modality for visualising the tumour and monitoring the ablation zone. The proceduralist may also employ protective measures to minimise injury to non-target organs. This review article discusses the important considerations an interventionalist needs to consider when performing the percutaneous ablation of liver tumours. It covers the different ablative modalities, image guidance, and protective techniques, with an emphasis on new and advanced ablative modalities and adjunctive techniques to optimise results and achieve satisfactory ablation margins.

Objective: To explore various microwave (MW) time/power combinations to achieve maximum single-probe system performance in a live pig liver model. Methods: Fifty-one microwave ablations performed in 12 female pigs using the following time/power combinations: 65 W for 10 min (65W 10MIN), ramped from 20 to 65 W (RAMPED), 95 W pulses with cooling periods (95W PULSED), 40 W for 16 min 15 s (LOW POWER), 1 min 95 W pulse then 8 min 65 W then a second 1 min 95 W pulse (BOOKEND 95W) and 65 W for 15 min (65W 15MIN). Temperatures 1.5 cm from the antenna were measured. Livers were excised, and ablations were measured and compared. Results: At fixed overall energy, LOW POWER produced ablation zones with the smallest volume compared to 65W 10MIN, RAMPED and 95W PULSED. At a fixed time of 10-min, BOOKEND 95W protocol achieved wider and larger ablation zones than 65W 10MIN (p = 0.038, p = 0.008) and 95W PULSED (p = 0.049, p = 0.004). The 65W 15MIN combination had significantly larger diameters (p = 0.026), larger lengths (p = 0.014) and larger volumes (p = 0.005) versus 65W 10MIN. Maximum temperatures were highest with BOOKEND 95W (62.9 °C) and 65 W 15 MIN (63.0 °C) and lowest with LOW POWER (45.9 °C), p = 0.009. Conclusions: Low power ablations, even if controlled for total energy delivery, create small ablation zones. High peak powers are associated with larger ablation zones and high margin temperatures if cooling pauses are avoided. Ramping and pulsing protocols with interleaved cooling appear to be of no benefit versus continuous 65 W for creating large ablation zones.

Objective:To assess the feasibility of cone-beam computed tomography (CBCT) in achieving unipedicular access during spinal cement augmentation.Methods:A retrospective review of all patients who underwent CBCT-guided unipedicular spinal augmentation procedures between 1st January 2012 and 15th June 2015 was performed. Fifty-nine patients (43 women 16 men; mean-age, 74.0 years; range, 52-90 years) underwent unipedicular spinal augmentation in 78 vertebral levels (T5-T9 n=14, T10-L2 n=42, L3-L5 n=22). Degree of crossover in contralateral hemi-vertebral body, complications and 30-day mortality were recorded.Results:Ninety-seven percent (76/78) of procedures were technically successful. Two procedures failed due to vertebral sclerosis; For vertebroplasty, all cases (6/6) demonstrated crossover filling of cement, and 50% (3/6) showed cement crossover >50% of contralateral half. For kyphoplasty, 13 out of 15 demonstrated balloon and cement crossover >50% of contralateral half. Two kyphoplasty procedures required...