Minimally invasive thermal ablation of tumours has become common since the advent of modern imaging. From the ablation of small, unresectable tumours to experimental therapies, percutaneous radiofrequency ablation, microwave ablation, cryoablation and irreversible electroporation have an increasing role in the treatment of solid neoplasms. This Opinion article examines the mechanisms of tumour cell death that are induced by the most common thermoablative techniques and discusses the rapidly developing areas of research in the field, including combinatorial ablation and immunotherapy, synergy with conventional chemotherapy and radiation, and the development of a new ablation modality in irreversible electroporation.

Thermal ablation of tumours: biological mechanisms and advances in therapy.

The main objective of this document is to improve precision in communication in the field of image-guided tumor ablation that leads to more accurate comparison of technologies and results and ultimately to improved patient outcomes.

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Image-guided Tumor Ablation: Standardization of Terminology and Reporting Criteria—A 10-Year Update

Cancer of the pancreas: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

Diagnosis and Treatment of Non-Muscle Invasive Bladder Cancer: AUA/SUO Guideline

As multidetector CT has come to play a more central role in medical care and as CT image quality has improved, there has been an increase in the frequency of detecting “incidental findings,” defined as findings that are unrelated to the clinical indication for the imaging examination performed. These “incidentalomas,” as they are also called, often confound physicians and patients with how to manage them. Although it is known that most incidental findings are likely benign and often have little or no clinical significance, the inclination to evaluate them is often driven by physician and patient unwillingness to accept uncertainty, even given the rare possibility of an important diagnosis. The evaluation and surveillance of incidental findings have also been cited as among the causes for the increased utilization of cross-sectional imaging. Indeed, incidental findings may be serious, and hence, when and how to evaluate them are unclear. The workup of incidentalomas has varied widely by physician and region, and some standardization is desirable in light of the current need to limit costs and reduce risk to patients. Subjecting a patient with an incidentaloma to unnecessary testing and treatment can result in a potentially injurious and expensive cascade of tests and procedures. With the participation of other radiologic organizations listed herein, the ACR formed the Incidental Findings Committee to derive a practical and medically appropriate approach to managing incidental findings on CT scans of the abdomen and pelvis. The committee has used a consensus method based on repeated reviews and revisions of this document and a collective review and interpretation of relevant literature. This white paper provides guidance developed by this committee for addressing incidental findings in the kidneys, liver, adrenal glands, and pancreas.

Managing incidental findings on abdominal CT: white paper of the ACR incidental findings committee.

Further characterization of the thermal profile created with additional types of clinically used electrodes and other common energy parameters selected is therefore mandated to better understand the best ways to avoid unintended thermal damage when ablating near sensitive critical structures.

https://pubs.rsna.org/doi/pdf/10.1148/radiol.12120609

Irreversible Electroporation Ablation: Is All the Damage Nonthermal?

Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric procedure, and it can be done as an isolated LSG or in conjunction with biliopancreatic diversion bypass/duodenal switch (laparoscopic duodenal switch; LDS). Gastroesophageal reflux after LSG has been described, but the mechanism is unknown and the treatment in the severest cases has not been discussed. We describe a cohort of patients who have underwent an LSG or LDS, and have suffered from a severe postoperative gastroesophageal motility disorder and/or reflux, report on their treatment, and discuss possible underlying mechanisms. Seven hundred and six patients underwent an LSG by two of the authors (AK, AB). Sixty nine patients underwent laparoscopic sleeve gastrectomy in Hadassah Medical Center, Jerusalem, Israel (January, 2006 and December 2008; 55 isolated LSG, 14 with LDS), and 637 (212 isolated LSG, 425 LDS) in Clinica San Jorge and Alcoy Hospital in Alcoy, Spain, (January 2002 and November 2008). Of them, eight patients who has suffered from a gastroesophageal dysmotility and reflux disease postoperatively and needed a specific treatment besides regular proton pump inhibitors (PPIs) were identified (1.1%). A combination of dilated upper part of the sleeve with a relative narrowing of the midstomach, without complete obstruction, was common to all eight patients who suffered from a severe gastroesophageal dysmotility and reflux. The sleeve volume, the bougie size, and the starting point of the antral resection do not seem to have an effect in this complication. Operative treatment was needed in only one case out of eight; in the rest of the patients, medical modalities were successful. More knowledge is required to understand the underlying mechanisms.

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Dilated Upper Sleeve Can be Associated with Severe Postoperative Gastroesophageal Dysmotility and Reflux

US findings in the acute period after irreversible electroporation are dynamic and evolve; the ablation zone can be best predicted by measuring the external hyperechoic rim that forms 90–120 minutes after ablation, possibly owing to hemorrhagic infiltration via widened sinusoids.

US Findings after Irreversible Electroporation Ablation: Radiologic-Pathologic Correlation

OBJECTIVE. The purpose of this study was to prospectively characterize and optimize irreversible electroporation ablation to determine the best parameters to achieve the largest target zones of coagulation for two electrodes. MATERIALS AND METHODS. Ultrasound-guided irreversible electroporation ablation (n = 110) was performed in vivo in 25 pig livers using two 18-gauge electroporation electrodes and an irreversible electroporation generator. Five variables for energy deposition and electrode configuration were sequentially studied: number of electrical pulses (n = 20–90), length of pulses (20–100 microseconds), generator voltage (2250–3000 V), interelectrode spacing (1.5–2.5 cm), and length of active electrode exposure (1.0–3.0 cm). Zones of ablation were determined at gross pathology and histopathology 2–3 hours after irreversible electroporation. Dimensions were compared and subjected to statistical analysis. RESULTS. For 1.5-cm spacing and 2-cm electrode exposure at 2250 V, there was no statistical di...

https://www.ajronline.org/doi/pdf/10.2214/AJR.11.6940

Characterization of Irreversible Electroporation Ablation in In Vivo Porcine Liver

OBJECTIVE. Adnexal torsion is most commonly a clinical diagnosis, often aided by sonographic findings. At times, the clinical presentation can mimic nongynecologic causes of acute lower abdominal pain. In these cases, CT may be the initial imaging study. The purpose of this study was to define the CT features associated with adnexal torsion.CONCLUSION. On CT, a well-defined adnexal mass abnormally located in the pelvis with ipsilateral deviation of the uterus in a woman or girl with lower abdominal pain should raise the suspicion of adnexal torsion. Inflammatory signs on CT suggest the presence of necrosis.

https://www.ajronline.org/doi/pdf/10.2214/AJR.06.0073

Liat Appelbaum

Papers

Irreversible Electroporation Ablation: Is All the Damage Nonthermal?

Dilated Upper Sleeve Can be Associated with Severe Postoperative Gastroesophageal Dysmotility and Reflux

US Findings after Irreversible Electroporation Ablation: Radiologic-Pathologic Correlation

Characterization of Irreversible Electroporation Ablation in In Vivo Porcine Liver

CT Features of Adnexal Torsion