Thermal ablation is an emerging, potentially curative approach in treating primary and metastatic liver cancer. Different technologies are available, with radiofrequency ablation (RFA) and microwave ablation (MWA) being the most widely used. Regardless of the technique, destruction of the entire tumor, including an adequate safety margin, is key. In conventional single-probe US- or CT-guided thermal ablation, the creation of such large necrosis zones is often hampered by technical limitations, especially for large tumors (i.e., >2–3 cm). These limitations have been overcome by stereotactic RFA (SRFA): a multiple needle approach with 3D treatment planning and precise stereotactic needle placement combined with intraprocedural image fusion of pre- and post-interventional CT scans for verification of treatment success. With these sophisticated tools and advanced techniques, the spectrum of locally curable liver malignancies can be dramatically increased. Thus, we strongly believe that stereotactic thermal ablation can become a cornerstone in the treatment of liver malignancies, as it offers all the benefits of a minimally invasive method while providing oncological outcomes comparable to surgery. This article provides an overview of current stereotactic techniques for thermal ablation, summarizes the available clinical evidence for this approach, and discusses its advantages.

To evaluate the efficacy, safety and overall clinical outcome of multiprobe SRFA as a treatment for recurrent colorectal liver metastases after hepatic resection (HR). A retrospective, single center study carried out between 2006 and 2018. 64 consecutive patients with recurrent or new CRLM after previous HR were treated by SRFA for 217 lesions (median size 2.7 cm, 1-7.5) in 103 ablation sessions. Endpoints consisted of i) technical efficacy ii) complication and mortality rates iii) local and distant recurrence, iv) disease free survival (DFS), and v) overall survival (OS). 213/217 tumors were successfully ablated at initial SRFA (97.7% primary technical efficacy rate). Four tumors required repeat ablation, resulting in a secondary technical efficacy rate of 99.5% (216/217). Local recurrence developed in 25/217 lesions (11.5%). Major complication rate was 5.8% (6/103 sessions) and mortality rate was 1.0% (1/103 ablation sessions), respectively.1-, 3-, and 5- year OS rates from date of first SRFA were 90.1%, 46.2%, and 34.8% (median 33.1 months). DFS rates were 54.2%, 17.2%, and 17.2%, at 1-, 3- and 5- years, respectively (median 13.3 months). SRFA is a safe, feasible and effective option for CRLM after HR with low morbidity levels and favorable clinical outcome.

Background: Robotic-based guidance systems are becoming increasingly capable of assisting in needle placement during interventional procedures. Despite these technical advances, less sophisticated low-cost guidance devices promise to enhance puncture accuracy compared with the traditional freehand technique. Purpose: To compare the in vitro accuracy and feasibility of two different aiming devices for computed-tomography (CT)-guided punctures. Methods: A total of 560 CT-guided punctures were performed by using either a robotic (Perfint Healthcare: Maxio) or a novel low-cost patient-mounted system (Medical Templates AG: Puncture Cube System [PCS]) for the placement of Kirschner wires in a plexiglass phantom with different slice thicknesses. Needle placement accuracy as well as procedural time were assessed. The Euclidean (ED) and normal distances (ND) were calculated at the entry and target point. Results: Using the robotic device, the ND at the target for 1.25 mm, 2.5 mm, 3.75 mm and 5 mm slice thickness were 1.28 mm (SD ± 0.79), 1.25 mm (SD ± 0.81), 1.35 mm (SD ± 1.00) and 1.35 mm (SD ± 1.03). Using the PCS, the ND at the target for 1 mm, 3 mm and 5 mm slices were 3.84 mm (SD ± 1.75), 4.41 mm (SD ± 2.31) and 4.41 mm (SD ± 2.11), respectively. With all comparable slice thicknesses, the robotic device was significantly more accurate compared to the low-cost device (p < 0.001). Needle placement with the PCS resulted in lower intervention time (mean, 158.83 s [SD ± 23.38] vs. 225.67 s [SD ± 17.2]). Conclusion: Although the robotic device provided more accurate results, both guidance systems showed acceptable results and may be helpful for interventions in difficult anatomical regions and for those requiring complex multi-angle trajectories.

Aim: Torsion of the testicular appendages represents the most common cause of an acute scrotum in prepubertal boys. Its sonographic appearances on gray-scale US and color Doppler US have already been presented in several studies. The aim of this analysis was to expand those already established techniques with strain elastography and thus present typical features of this entity on multiparametric US.Material and methods: Retrospective analysis of all patients presented to the urological department with an acute scrotum between January 2018 and July 2020 identified eleven patients 6-17 years old (mean, 11.1 years), discharged with the diagnosis torsion of the testicular appendages that were examined with a high-end ultrasound device. Results: On gray-scale US all patients showed a round lesion with heterogenous echotexture adjacent to the upper pole of the testis/epididymis with a diameter of 4 to 11.1 mm (mean, 7.7 mm). Scrotal skin thickening and a concomitant hydrocele were found in 9 (81.8%) and 7 (63.6%) cases, respectively. On color Doppler images, all torsed appendages were avascular and in 9 (81.8%) patients we observed hyperemia of the adjacent epididymis. Strain elastography showed increased tissue stiffness in all documented images.Conclusion: Torsion of the testicular appendages has a set of features on multiparametric US. Awareness of this features can facilitate diagnosis of torsion of the testicular appendages and reduce unnecessary surgicalscrotal exploration or unwarranted antibiotic treatment.