The field of interventional oncology with use of image-guided tumor ablation requires standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments that use different technologies, such as chemical (ethanol or acetic acid) ablation, and thermal therapies, such as radiofrequency, laser, microwave, ultrasound, and cryoablation. This document provides a framework that will hopefully facilitate the clearest communication between investigators and will provide the greatest flexibility in comparison between the many new, exciting, and emerging technologies. An appropriate vehicle for reporting the various aspects of image-guided ablation therapy, including classification of therapies and procedure terms, appropriate descriptors of imaging guidance, and terminology to define imaging and pathologic findings, are outlined. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the group's intention that adherence to the recommendations will facilitate achievement of the group's main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and, ultimately, to improved patient outcomes.

https://radiologie-uni-frankfurt.de/sites/radiologieinstitut/content/e4864/e299/e1255/e10384/Goldberg_Image-guidedtumorablation_standardizationofterminology_ger.pdf

Image-guided Tumor Ablation: Standardization of Terminology and Reporting Criteria

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.

/pdf/image-guided-tumor-ablation-standardization-of-terminology-2zniyc9l69.pdf

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

Microwave ablation is the most recent development in the field of tumor ablation. The technique allows for flexible approaches to treatment, including percutaneous, laparoscopic, and open surgical access. With imaging guidance, the tumor is localized, and a thin (14.5-gauge) microwave antenna is placed directly into the tumor. A microwave generator emits an electromagnetic wave through the exposed, noninsulated portion of the antenna. Electromagnetic microwaves agitate water molecules in the surrounding tissue, producing friction and heat, thus inducing cellular death via coagulation necrosis. The main advantages of microwave technology, when compared with existing thermoablative technologies, include consistently higher intratumoral temperatures, larger tumor ablation volumes, faster ablation times, and an improved convection profile. Microwave ablation has promising potential in the treatment of primary and secondary liver disease, primary and secondary lung malignancies, renal and adrenal tumors, and bone metastases. The technology is still in its infancy, and future developments and clinical implementation will help improve the care of patients with cancer.

https://pubs.rsna.org/doi/pdf/10.1148/rg.25si055501

Microwave ablation : Principles and applications

Hepatocellular carcinoma (HCC) is a common cause of death in patients with cirrhosis. Cirrhosis develops as a result of chronic liver injury secondary to extrinsic environmental factors in the vast majority of affected individuals. Hepatitis B or C virus infection, aflatoxin B1 or other mycotoxin ingestion, and prolonged ethanol abuse are the major causes of cirrhosis. 1 The worldwide population at risk for developing HCC because of one or more of these etiologic factors numbers in the tens of millions: in the United States and Italy, for example, there are an estimated 7.5 million persons with chronic hepatitis C virus infection. 2,3

In most patients with HCC, treatment options are limited by the liver dysfunction caused by chronic inflammation and cirrhosis. Although complete surgical resection of HCC offers the best chance of long-term survival, cirrhosis may limit the amount of parenchymal resection that will be tolerated and increases the risk of postoperative liver failure and death. 4–6 Systemic or regional chemotherapy is at best palliative in a small subset of patients (although rarely patients have sufficient tumor downstaging to convert an unresectable to a resectable lesion), but at the cost of significant side effects and a reduced quality of life. 1 In most patients with cirrhosis and HCC confined to the liver, resection is not safe, and local tumor-ablation therapies are considered as alternative treatment options.

Radiofrequency ablation (RFA) is a thermal treatment technique designed to produce localized tumor destruction by heating tumor tissue to temperatures that exceed 50°C. When tumor cells are heated to temperatures above 45° to 50°C for more than 3 minutes, intracellular protein denaturation and melting of lipid bilayers results in direct tumor cell death. 7–10 RFA uses alternating current passed across needle electrode arrays placed directly into the tumor. Ionic stimulation induced by the alternating current in tissue surrounding the electrode array produces gradual frictional heating, and the tissue temperatures rise to 80° to 110°C, which results in coagulative necrosis of the tissue in proximity to the electrode. The basic principle is similar to that of the surgical electrocautery units used to achieve intraoperative hemostasis.

We performed this prospective study using RFA to treat HCC in patients with cirrhosis to determine treatment efficacy, safety, local tumor control, patterns of failure, and treatment-related complications.

Radiofrequency ablation of hepatocellular cancer in 110 patients with cirrhosis.

https://aasldpubs.onlinelibrary.wiley.com/doi/pdf/10.1053/jhep.2000.20456

Results of surgical and nonsurgical treatment for small-sized hepatocellular carcinomas: A retrospective and nationwide survey in Japan

BACKGROUND

A small number of microwave electrode insertions and microwave irradiations were used to obtain complete tumor necrosis in hepatocellular carcinomas (HCC) measuring > 2.0 cm but ≤ 3.0 cm in greatest dimension. The efficacy of combining transcatheter arterial chemoembolization (TACE) with subsequent percutaneous microwave coagulation therapy (PMCT) was assessed in this study.



METHODS

Eighteen patients with cirrhosis and HCCs measuring > 2.0 cm but ≤ 3.0 cm in greatest dimension underwent TACE followed within 1–2 days by ultrasonographically guided PMCT.



RESULTS

On dynamic computed tomography, 17 of the 18 patients showed complete necrosis of their tumor lesions and the treated tumor margins (≥ 5 mm). Necroses of tumors and noncancerous margins surrounding the tumors were obtained using 4 microwave irradiations (1 session) in 14 patients, 5 microwave irradiations (2 sessions) in 2 patients, and 6 microwave irradiations (2 sessions) in 1 patient.



The follow-up period was short (12–31 mos), and all patients remained alive. No local recurrences in the treated areas were detected. No fatal complications were observed. Pleural effusion was observed in 1 patient only.



CONCLUSIONS

This combined therapy of PMCT applied within 1–2 days of TACE effectively treated HCCs measuring > 2.0 cm but ≤ 3.0 cm in greatest dimension. A small number of microwave electrode insertions and microwave irradiations were used. Cancer 2000;89:1245–51. © 2000 American Cancer Society.

Combination therapy with transcatheter arterial chemoembolization and percutaneous microwave coagulation therapy for hepatocellular carcinoma

We report one patient who showed rapid progression of hepatocellular carcinoma (HCC) after undergoing transcatheter arterial chemoembolization (TACE) and percutaneous radiofrequency ablation (PRFA) for a small HCC measuring 2.5 cm in diameter. Enhanced magnetic resonance imaging (MRI) following treatment showed complete tumour necrosis and did not reveal the presence of a tumour around the treated area. Furthermore, the serum alpha-fetoprotein (AFP) level decreased at the completion of therapy. However, the HCC advanced in a very short time. Numerous tumours around the treated area were observed on enhanced computed tomography (CT) 50 days after PRFA. It is strongly suspected that the tumour was disseminated through the portal system because of the presence pattern of tumours. We believe this to be the first case illustrating a hepatic cancer that progressed rapidly following TACE and PRFA.

Rapid progression of hepatocellular carcinoma after transcatheter arterial chemoembolization and percutaneous radiofrequency ablation in the primary tumour region.

Percutaneous microwave coagulation therapy for solitary metastatic liver tumors from colorectal cancer: a pilot clinical study

Since November 1973, intraoperative radiotherapy has been performed on five patients with unresectable, advanced carcinoma of the bile duct at the hepatic hilus and six patients with unresectable carcinoma of the gallbladder. A treatment cone with a diameter ranging from 4--10 cm was directly applied at the lesion. A single dose of 2500--3000 rad with 11 to 20 meV electrons was delivered. In all patients, recanalization of the obstructed bile duct was observed by the postoperative cholangiography. The local efficacy was confirmed histopathologically in eight autopsied materials and a specimen resected 105 days after radiotherapy. Mean survival time of patients with unresectable tumors was 10.9 +/- 5.6 (SD) months after this radiotherapy. Intraoperative radiotherapy increased the effectiveness and length of palliation for the unresectable lesion.

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.1002/1097-0142%2819801115%2946%3A10%3C2179%3A%3AAID-CNCR2820461014%3E3.0.CO%3B2-Y

Intraoperative radiotherapy for advanced carcinoma of the biliary system

The objective of this study was to clarify the relationship between the serum level of the Lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (AFP-L3) and the clinical features including sex, age, Child's classification, virus markers, tumour size, tumour stage, distant metastasis, histopathologic findings, portal thrombus and outcome of hepatocellular carcinoma (HCC). We measured the AFP-L3 levels in 170 HCC cases at the time of diagnosis using lectin-affinity electrophoresis followed by antibody-affinity blotting. The patients were divided into two groups, those who were AFP-L3 positive (n=56; AFP-L3 >/=15% relative to the total alpha-fetoprotein (AFP) concentration) and those who were AFP-L3 negative (n=114; AFP-L3 <15%). Then we examined the association between the serum AFP-L3 level and the clinical features of HCC. No significant differences were found in age, sex, and virus markers between the AFP-L3-positive and -negative groups. However, patients in the positive group had worse liver function and larger tumours compared to the negative group. They also had more advanced cancer with poor tumour histology compared to the negative group. Distant metastasis was diagnosed significantly more often in the positive group than that in the negative group. There was no significant correlation between the AFP-L3 level and portal thrombus. Although the follow-up period was brief the prognosis for the positive group clearly was poor. These results suggest that AFP-L3 is a useful indicator of distant metastasis and a poor prognosis for HCC.

Usefulness of Lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (AFP-L3) as a marker of distant metastasis from hepatocellular carcinoma.

Akira Nishimura

Papers

Combination therapy with transcatheter arterial chemoembolization and percutaneous microwave coagulation therapy for hepatocellular carcinoma

Rapid progression of hepatocellular carcinoma after transcatheter arterial chemoembolization and percutaneous radiofrequency ablation in the primary tumour region.

Percutaneous microwave coagulation therapy for solitary metastatic liver tumors from colorectal cancer: a pilot clinical study

Intraoperative radiotherapy for advanced carcinoma of the biliary system

Usefulness of Lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (AFP-L3) as a marker of distant metastasis from hepatocellular carcinoma.