Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update

Long-term results of liver thermal ablation in patients with hepatocellular carcinoma and colorectal cancer liver metastasis regarding spatial features and tumor-specific variables

PURPOSE

Colorectal cancer liver metastasis (CRLM) and hepatocellular carcinoma (HCC) are widely treated using microwave and radiofrequency ablation. Local tumor progression (LTP) may develop depending on the shortest vascular distance and large lesion diameter. This study aims to explore the effect of these spatial features and to investigate the correlation between tumor-specific variables and LTP.

METHODS

This is a retrospective study covering the period between January 2007 and January 2019. One hundred twenty-five patients (CRLM: HCC: 64:61) with 262 lesions (CRLM: HCC: 142:120) were enrolled. The correlation between LTP and the variables was analyzed using the chi-square test, Fischer's exact test, or the Fisher-Freeman-Halton test where applicable. The local progression-free survival (Loc-PFS) was analyzed using the Kaplan-Meier method. Univariable and multivariable Cox regression analyses were performed to identify prognostic factors.

RESULTS

Significant correlations were observed for LTP in both CRLM and HCC at a lesion diameter of 30-50 mm (P = 0.019 and P < 0.001, respectively) and SVD of ≤3 mm (P < 0.001 for both). No correlation was found between the ablation type and LTP (CRLM: P = 0.141; HCC: P = 0.771). There was no relationship between residue and the ablation type, but a strong correlation with tumor size was observed (P = 0.127 and P < 0.001, respectively). In CRLM, LTP was associated with mutant K-ras and concomitant lung metastasis (P < 0.001 and P = 0.003, respectively). In HCC, a similar correlation was found for Child-Pugh B, serum alpha-fetoprotein (AFP) level of >10 ng/mL, predisposing factors, and moderate histopathological differentiation (P < 0.001, P = 0.008, P = 0.027, and P < 0.001, respectively). In CRLM, SVD of ≤3 mm proved to be the variable with the greatest negative effect on Loc-PFS (P = 0.007), followed by concomitant lung metastasis (P = 0.027). In HCC, a serum AFP level of >10 ng/mL proved to be the variable with the greatest negative effect on Loc-PFS (P = 0.045).

CONCLUSION

In addition to the lesions' spatial features, tumor-specific variables may also have an impact on LTP.

Safety and efficacy of percutaneous image-guided ablation for soft tissue sarcoma metastases to the liver

PURPOSE

To evaluate outcomes following percutaneous image-guided ablation of soft tissue sarcoma metastases to the liver.

MATERIALS AND METHODS

A single-institution retrospective analysis of patients with a diagnosis of metastatic soft tissue sarcoma who underwent percutaneous image-guided ablation of hepatic metastases between January 2011 and December 2021 was performed. Patients with less than 60 days of follow-up after ablation were excluded. The primary outcome was local tumor progression-free survival (LPFS). Secondary outcomes included overall survival, liver-specific progression-free survival. and chemotherapy-free survival.

RESULTS

Fifty-five patients who underwent percutaneous ablation for 84 metastatic liver lesions were included. The most common histopathological subtypes were leiomyosarcoma (23/55), followed by gastrointestinal stromal tumor (22/55). The median treated liver lesions was 2 (range, 1-8), whereas the median size of metastases were 1.8 cm (0.3-8.7 cm). Complete response at 2 months was achieved in 90.5% of the treated lesions. LPFS was 83% at 1 year and 80% at 2 years. Liver-specific progression-free survival was 66% at 1 year and 40% at 2 years. The overall survival at 1 and 2 years was 98% and 94%. The chemotherapy-free holiday from the start of ablation was 71.2% at 12 months. The complication rate was 3.6% (2/55); one of the complications was Common Terminology Criteria for Adverse Events grade 3 or higher. LPFS subgroup analysis for leiomyosarcoma versus gastrointestinal stromal tumor suggests histology-agnostic outcomes (2 years, 89% vs 82%, p = .35).

CONCLUSION

Percutaneous image-guided liver ablation of soft tissue sarcoma metastases is safe and efficacious.

Imaging Considerations before and after Liver-Directed Locoregional Treatments for Metastatic Colorectal Cancer

Colorectal cancer is a leading cause of cancer-related death. Liver metastases will develop in over one-third of patients with colorectal cancer and are a major cause of morbidity and mortality. Even though surgical resection has been considered the mainstay of treatment, only approximately 20% of the patients are surgical candidates. Liver-directed locoregional therapies such as thermal ablation, Yttrium-90 transarterial radioembolization, and stereotactic body radiation therapy are pivotal in managing colorectal liver metastatic disease. Comprehensive pre- and post-intervention imaging, encompassing both anatomic and metabolic assessments, is invaluable for precise treatment planning, staging, treatment response assessment, and the prompt identification of local or distant tumor progression. This review outlines the value of imaging for colorectal liver metastatic disease and offers insights into imaging follow-up after locoregional liver-directed therapy.

Three-Dimensional Margin as a Predictor of Local Tumor Progression after Microwave Ablation: Intraprocedural versus 4-8-Week Postablation Assessment

PURPOSE

To evaluate the prognostic accuracy of intraprocedural and 4-8-week (current standard) post-microwave ablation zone (AZ) and margin assessments for prediction of local tumor progression (LTP) using 3-dimensional (3D) software.

MATERIALS AND METHODS

Data regarding 100 colorectal liver metastases (CLMs) in 75 patients were collected from 2 prospective fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT)-guided microwave ablation (MWA) trials. The target CLMs and theoretical 5- and 10-mm margins were segmented and registered intraprocedurally and at 4-8 weeks after MWA contrast-enhanced CT (or magnetic resonance [MR] imaging) using the same methodology and 3D software. Tumor and 5- and 10-mm minimal margin (MM) volumes not covered by the AZ were defined as volumes of insufficient coverage (VICs). The intraprocedural and 4-8-week post-MWA VICs were compared as predictors of LTP using receiver operating characteristic curve analysis.

RESULTS

The median follow-up time was 19.6 months (interquartile range, 7.97-36.5 months). VICs for 5- and 10-mm MMs were predictive of LTP at both time assessments. The highest accuracy for the prediction of LTP was documented with the intra-ablation 5-mm VIC (area under the curve [AUC], 0.78; 95% confidence interval, 0.66-0.89). LTP for a VIC of 6-10-mm margin category was 11.4% compared with 4.3% for >10-mm margin category (P < .001).

CONCLUSIONS

A 3D 5-mm MM is a critical endpoint of thermal ablation, whereas optimal local tumor control is noted with a 10-mm MM. Higher AUCs for prediction of LTP were achieved for intraprocedural evaluation than for the 4-8-week postablation 3D evaluation of the AZ.

Transbronchial Microwave Ablation of Peripheral Lung Tumors: The NAVABLATE Study

BACKGROUND

Image-guided thermal ablation is a minimally invasive local therapy for lung malignancies. NAVABLATE characterized the safety and performance of transbronchial microwave ablation (MWA) in the lung.

METHODS

The prospective, single-arm, 2-center NAVABLATE study (NCT03569111) evaluated transbronchial MWA in patients with histologically confirmed lung malignancies ≤30 mm in maximum diameter who were not candidates for, or who declined, both surgery and stereotactic body radiation therapy. Ablation of 1 nodule was allowed per subject. The nodule was reached with electromagnetic navigation bronchoscopy. Cone-beam computed tomography was used to verify the ablation catheter position and to evaluate the ablation zone postprocedure. The primary end point was composite adverse events related to the transbronchial MWA device through 1-month follow-up. Secondary end points included technical success (nodule reached and ablated according to the study protocol) and technique efficacy (satisfactory ablation based on 1-month follow-up imaging).

RESULTS

Thirty subjects (30 nodules; 66.7% primary lung, 33.3% oligometastatic) were enrolled from February 2019 to September 2020. The pre-procedure median nodule size was 12.5 mm (range 5 to 27 mm). Procedure-day technical success was 100% (30/30), with a mean ablative margin of 9.9±2.7 mm. One-month imaging showed 100% (30/30) technique efficacy. The composite adverse event rate related to the transbronchial MWA device through 1-month follow-up was 3.3% (1 subject, mild hemoptysis). No deaths or pneumothoraces occurred. Four subjects (13.3%) experienced grade 3 complications; none had grade 4 or 5.

CONCLUSION

Transbronchial microwave ablation is an alternative treatment modality for malignant lung nodules ≤30 mm. There were no deaths or pneumothorax. In all, 13.3% of patients developed grade 3 or above complications.

High-intensity focused ultrasound for endometrial ablation in adenomyosis: a clinical study

Objective

The present study aimed to investigate the clinical efficacy of endometrial ablation with high-intensity focused ultrasound (HIFU) for symptom relief in women with adenomyosis.

Methods

Between July 2014 and July 2020, 167 patients with adenomyosis treated at the Zhongshan City People's Hospital were enrolled in this study. Patients were divided into two groups according to patient aspirations: the control group, including patients who only underwent ablation of adenomyosis lesions (group A) and the treatment group, including patients who underwent removal of adenomyosis lesions and endometrial ablation (group B).

Results

The reduced dysmenorrhea scores (visual analog scale) and menstrual volume scores (pictorial blood assessment chart) were measured before and after treatment. The scores were obtained by subtracting the postoperative scores from the preoperative scores and were compared to determine whether the symptoms had alleviated. Compared with the menstrual volume of group A, that in group B showed significant improvements. The average relief rates of dysmenorrhea in the two groups also showed significant improvement. However, the scores in group B showed a more significant improvement than those in group A.

Conclusion

Therefore, our findings suggest that endometrial ablation using HIFU may be superior to conventional therapy with regard to alleviating the symptoms of increased menstruation in women with adenomyosis.

Clinical outcomes of percutaneous microwave ablation for pulmonary oligometastases from hepatocellular carcinoma: a retrospective, multicenter study

BACKGROUND

Pulmonary oligometastases are common in hepatocellular carcinoma (HCC), however, the existing therapeutic options have several limitations. This study aimed to assess the safety and efficacy of microwave ablation (MWA) in the treatment of HCC-originating pulmonary oligometastases.

METHODS

A total of 83 patients, comprising 73 males and 10 females with a median age of 57 years, who had pulmonary oligometastases from HCC, underwent MWA treatment at four different medical institutions. Inclusion criteria for patients involved having primary HCC under control and having less than three oligometastases with a maximum diameter of ≤ 5 cm in the unilateral lung or less than five oligometastases with a maximum diameter of ≤ 3 cm in the bilateral lung. A total of 147 tumors were treated with MWA over 116 sessions. The primary endpoints assessed included technical success, treatment efficacy, and local progression rate, while secondary endpoints encompassed complications, clinical outcomes, overall survival (OS), local progression-free survival (LPFS), and prognostic factors.

RESULTS

The technical success rate for MWA was 100% (116/116 sessions), and the treatment efficacy rate was 82.3% (121/147 tumors). Six months after MWA, the local progression rate was 23.1% (18/147 tumors). Complications were observed in 10.3% (major) and 47.4% (minor) of the 116 sessions, with no cases of ablation-related deaths. The median follow-up period was 21.6 months (range: 5.7-87.8 months). Median OS was 22.0 months, and the 1-, 2-, and 3-year OS rates were 82.6%, 44.5%, and 25.2%, respectively. Median LPFS was 8.5 months. Multivariate Cox regression analysis identified α-fetoprotein (AFP) levels during initial diagnosis and the number of oligometastases as potential independent prognostic factors for OS (p = 0.017 and 0.045, respectively).

CONCLUSION

Percutaneous MWA is a safe and effective treatment modality for pulmonary oligometastases originating from HCC.

Cholecystokinin to Enhance the Safety of Ablation of Liver Tumors Adjacent to the Gallbladder

This retrospective case review describes the potential for intravenous cholecystokinin (CCK) to improve the safety margin between the hepatic tumor and gallbladder (GB) for hepatic tumor ablation. Eight patients with primary hepatic neoplasms adjacent to the GB underwent CCK administration before ablation. GB volume and contact area measurements were performed before and after CCK administration to assess the degree of contraction. The planned ablation was successful in 7 patients (88%) after CCK administration, although 5 patients (63%) also had hydrodissection. After CCK, the median GB volume reduction was 22%, and tumor contact area with the GB was reduced by 20%. There was no evidence for CCK-related adverse events. CCK administration before ablation of hepatic neoplasms abutting the GB is a safe and simple method that may be an adjunct to needle decompression or hydrodissection of the GB.

Efficacy and influencing factor analysis of high-intensity focused ultrasound therapy for abdominal wall endometriosis: a case series

OBJECTIVE

The aim of this retrospective study was to investigate the short-term and long-term efficacy of high-intensity focused ultrasound (HIFU) therapy for abdominal wall endometriosis (AWE) and explore its potential influencing factors.

MATERIALS AND METHODS

A total of 80 patients with AWE who underwent HIFU therapy were retrospectively analyzed. Follow-ups were also conducted to evaluate the changes in lesion size and pain relief. Multivariate logistic regression analysis was applied to investigate factors influencing HIFU therapy for AWE.

RESULTS

Among the 80 patients with AWE who received HIFU therapy, the effective rates were 76.3%, 80.5%, and 90.5% after 3, 12 and 24 months of follow-up, respectively. Multivariate logistic regression analysis revealed that the AWE lesion diameter and sonication intensity had statistically significant effects on the 3-month and 12-month efficacy of HIFU therapy for AWE, while age, BMI, disease duration, average sonication power and grey-scale changes did not have statistically significant effects. Four patients with AWE experienced recurrence after HIFU therapy, for a three-year cumulative recurrence rate of 6.3%. Furthermore, ten patients required reintervention after treatment, for a five-year cumulative reintervention rate of 13.9%.

CONCLUSIONS

This study further confirmed the safety and effectiveness of HIFU therapy for AWE. Factors such as AWE lesion diameter and sonication intensity have been identified as key influencers affecting the short-term and long-term efficacy of HIFU therapy for AWE. The first two years following HIFU therapy constitute crucial periods for observation, and judiciously extending follow-up intervals during this timeframe is advised.

US-guided percutaneous irrigation of extra-shoulder calcific tendinitis

OBJECTIVES

To investigate the efficacy and safety of ultrasound-guided percutaneous irrigation of calcific tendinopathy (US-PICT) applied out of the shoulder, comparing its effectiveness to US-PICT of the rotator cuff.

METHODS

Patients subjected to US-PICT for extra-shoulder calcific tendinitis (Case Group) were compared to those subjected to US-PICT of the rotator cuff (Control Group). We had pre-procedure Visual Analogue Scale (VAS) pain score, 1- and 3-month VAS of patients of the Case Group, pre-procedure and 3-month VAS of patients of the Control Group.

RESULTS

The Case Group consisted of 41 patients (27 women; mean age: 45 ± 9years): 26 gluteus medius, 5 patellar tendon, 3 rectus femoris, 2 gluteus maximus, 2 common extensor tendon, 1 extensor carpi radialis longus, 1 pes anserinus, and 1 peroneus longus. The Control Group included 41 patients (27 women; mean age: 47 ± 11 years). The mean pre-procedure VAS of the Case Group was 8.8 ± 0.7 with a significant (P < .001) drop at 1 month (4.5 ± 0.6) and 3 months (3.6 ± 0.6). The mean pre-procedure VAS of the Control Group was 8 ± 1.4 and dropped to 3.1 ± 1.6 after 3 months (P < .001). Post-treatment VAS at 3 months was not significantly different between two Groups (P = 0.134). Similarly, the decrease of VAS from baseline to 3 months was not significantly different between the two Groups (P = 0.264).

CONCLUSIONS

US-PICT is a safe and effective procedure that can be used out of the shoulder.

ADVANCES IN KNOWLEDGE

This study demonstrated the safety and effectiveness of US-PICT as a valuable therapeutic option for extra-shoulder calcific tendinitis, with similar clinical outcome to the same procedure performed in the rotator cuff. The technique must be adapted in some deeply located calcifications by means of the use of different needles and by thoroughly planning the access point for the procedure.

Five-year follow-up results of thermal ablation for benign thyroid nodules: Systematic review and meta-analysis

OBJECTIVES

Confidence in long-term treatment results of thermal ablation for benign thyroid nodules (BTNs) is required in comparison with surgery. The objective of this meta-analysis is to report 5-year follow-up results of thermal ablation for BTNs.

METHODS

Ovid PUBMED, COCHRANE, and EMBASE databases were searched through Feb 30, 2023, for studies reporting outcomes in patients with BTNs treated with thermal ablation and followed up for about 5 years. Pooled volume reduction rates (VRRs) at 6, 12, 24, 36, 48, and 60 months after thermal ablation were assessed. Data were extracted and methodological quality was assessed independently by two radiologists according to the PRISMA guidelines.

RESULTS

Five studies, involving 939 patients, met the inclusion criteria through database searches. 137 patients experienced local nodules recurrence during a mean pooled 59.25-month follow-up. Seventeen of them proved to be non-benign. Fifty of all patients with nodules regrowth had a secondary surgery, while 35 had a secondary thermal ablation. The pooled mean major complication rate was 7.70 %, with no patient experiencing life-threatening or delayed complications.

CONCLUSIONS

Thermal ablation is an excellent local nodules control method in patients with BTNs, and results in a clinically significant and long-lasting volume reduction of BTNs. The risk of regrowth and needing retreatment was lower after thermal ablation.

Sonographic Evolution and Pathologic Findings of Papillary Thyroid Cancer After Radiofrequency Ablation: A Five-Year Retrospective Cohort Study

Background: The criteria for determining technical efficacy of thermal ablation for papillary thyroid carcinoma (PTC) are not clearly defined. We analyzed the involution process of the ablation zone with clear pathologic results on core-needle biopsy (CNB) to clarify the relationship between sonographic changes and pathologic findings. Methods: This retrospective cohort study included 382 patients with unifocal T1N0M0 PTC who underwent radiofrequency ablation (RFA) between May 2014 and August 2021. Patients with a single ablation zone biopsy (recommended at 3 or 6 months for T1a and 6 or 12 months for T1b) and regular neck ultrasound (US)/contrast-enhanced ultrasound imaging follow-up at 1, 3, 6, and 12 months and every 6-12 months thereafter after RFA were included. Patients also underwent yearly chest computed tomography. CNB was performed in the target lesion ablation zone's central, peripheral, and surrounding thyroid parenchyma to detect the presence of tumor cells. If the thyrotropin (TSH) was >2 mU/L, levothyroxine was prescribed with the intention of keeping the TSH 0.5-2 mU/L. Technical efficacy was defined as tumor disappearance by imaging follow-up together with the pathologically confirmed absence of tumor cells in the ablation zone. Results: During the mean follow-up period of 67.8 ± 18.2 months (22-110 months), the overall incidence of persistent disease and the technical efficacy rate were 3.9% (15/382; 2.9% of T1a, and 12.2% of T1b) and 96.1%, respectively. Tumor size (p = 0.03) and subcapsular location (p = 0.04) were risk factors associated with persistent disease. The technical success rate was 100%. Of the 367 ablation zones with benign CNB results, 336 (91.6%) showed tumor disappearance on US and no re-emergence of imaging-visible tumors during follow-up. Male sex (p = 0.006), age <40 years (p = 0.003), T1a tumor (p < 0.01), and energy per milliliter (p < 0.03) were significantly associated with tumor disappearance. Conclusions: US-guided RFA is an effective treatment for small low-risk PTC. Tumor disappearance on US after RFA may suggest an excellent prognosis and confirm complete ablation of the macroscopic tumor, but this sonographic finding is generally late and requires histological confirmation.

Radiofrequency Ablation for Benign Thyroid Nodules

CONTEXT

Thermal ablative techniques of the thyroid have recently gained clinical traction as a therapeutic alternative that provides symptomatic relief and confers potential advantages over surgery. A truly multidisciplinary technique, thyroid ablation is currently performed by endocrinologists, interventional radiologists, otolaryngologists, and endocrine surgeons. Radiofrequency ablation (RFA), specifically, has seen widespread adoption, particularly in the treatment of benign thyroid nodules. This review summarizes current evidence on the application of RFA in benign thyroid nodules, and provides a start to finish overview of procedural preparation, performance, and outcomes.

EVIDENCE ACQUISITION

A narrative review of literature focusing on RFA in the treatment of benign nodular disease was performed. Emphasis was placed on consensus statements, best practice guidelines, multi-institutional studies, and systematic reviews to summarize key concepts in candidacy, techniques, expectations, and outcomes.

FINDINGS

RFA is increasingly recognized as a first-line treatment strategy in the management of symptomatic nonfunctional benign thyroid nodules. It can also be considered in functional thyroid nodules with small volumes or in patients ineligible for surgery. A targeted and efficacious technique, RFA results in gradual volume reduction that preserves the function of the surrounding thyroid parenchyma. Proper procedural technique, proficiency in ultrasound, and experience in ultrasound-guided procedures are instrumental to maintaining low complication rates and achieving successful ablation outcomes.

CONCLUSIONS

In pursuit of a personalized approach, physicians across disciplines are increasingly incorporating RFA into their treatment algorithms, most commonly for benign nodules. As with any intervention, thoughtful selection and implementation ensure a safe procedure with optimal patient benefit.

Thermal ablation of hepatocellular carcinoma

Percutaneous treatment of hepatocellular carcinoma (HCC) by means of thermal ablation (TA) has been introduced in clinical guidelines as a potentially curative treatment for the early stages of the disease since the early 2000s. Due to its safety profile and cost-effectiveness, TA can be offered as a first-line treatment for patients with HCC smaller than 3 cm. Thermal ablative techniques are in fact widely available at many centres worldwide and include radiofrequency (RF) and microwave (MW) ablation, with the latter increasingly applied in clinical practice in the last decade. Pre-clinical studies highlighted, as potential advantages of MW-based ablation, the ability to achieve higher temperatures (>100°C) and larger ablation zones in shorter times, with less susceptibility to blood flow-induced heat sink effects. Despite these advantages, there is no evidence of superior overall survival in patients treated with MW as compared to those treated with RF ablation. Local control has been proven to be superior to MW ablation with a similar complication rate. It is expected that further improvement of TA results in the treatment of HCC will result from the refinement of guidance and monitoring tools and the careful assessment of ablation margins. Thermal ablative treatments may also be performed on nodules larger than 3 cm by applying multiple devices or combining percutaneous and intra-arterial approaches. The role of novel immunotherapy regimens in combination with ablation is also currently under evaluation in clinical trials, with several potential benefits. In this review, indications, technical principles, results, and future prospects of TA for the treatment of HCC will be examined.

Study Protocol STEREOLAB: Stereotactic Liver Ablation Assisted with Intra-Arterial CT Hepatic Arteriography and Ablation Confirmation Software Assessment

PURPOSE

This study aims to evaluate the technical efficacy and local tumor progression-free survival (LTPFS) of a standardized workflow for thermal ablation of colorectal liver metastases (CRLM) consisting of CT during hepatic arteriography (CTHA)-based imaging analysis, stereotactic thermal ablation, and computer-based software assessment of ablation margins.

MATERIALS AND METHODS

This investigator initiated, single-center, single-arm prospective trial will enroll up to 50 patients (≤ 5 CRLM, Measuring ≤ 5 cm). Procedures will be performed in an angio-CT suite under general anesthesia. The primary objective is to estimate LTPFS with a follow-up of up to 2 years and secondary objectives are analysis of the impact of minimal ablative margins on LTPFS, adverse events, contrast media utilization and radiation exposure, overall oncological outcomes, and anesthesia/procedural time. Adverse events (AE) will be recorded by CTCAE (Common Toxicity Criteria for Adverse Events), and Bayesian optimal phase-2 design will be applied for major intraprocedural AE stop boundaries. The institutional CRLM ablation registry will be used as benchmark for comparative analysis with the historical cohort.

DISCUSSION

The STEREOLAB trial will introduce a high-precision and standardized thermal ablation workflow for CRLM consisting of CT during hepatic arteriography imaging, stereotactic guidance, and ablation confirmation. Trial Registration ClinicalTrials.gov identifier: (NCT05361551).

Combination Therapy of Bland Transarterial Embolization and Microwave Ablation for Hepatocellular Carcinoma within the Milan Criteria Leads to Significantly Higher Overall Survival

A comparison of the combination therapy consisting of microwave ablation (MWA) after bland lipiodol-based transarterial embolization (TAE) with MWA alone in the treatment of hepatocellular carcinoma (HCC) within the Milan criteria. Forty-nine patients in the TAE-MWA group (12 women and 37 men; mean age: 63.3 ± 9.6 years) with 55 tumors and 63 patients in the MWA group (18 women and 45 men; mean age: 65.9 ± 10.5 years) with 67 tumors were retrospectively enrolled in this study. For the investigation of treatment protocols based upon both safety and efficacy, patients' cases were analyzed with regard to complications, local tumor progression (LTP), intrahepatic distant recurrence (IDR), overall survival (OS), and progression-free survival (PFS). There were no cases of major complications in either group. The LTP rate was 5.5% in the MWA-TAE group and 7.5% in the MWA group (p = 0.73). The rate of IDR was 42.9% in the MWA-TAE group and 52.4% in the MWA group (p = 0.42). The 12-, 24-, and 36-month OS rates starting at the date of tumor diagnosis were 97.7%, 85.1%, and 78.8% in the TAE-MWA group, and 91.9%, 71.4%, and 59.8% in the MWA group, respectively (p = 0.004). The 6-, 12-, and 24-month PFS rates were 76.5%, 55%, and 44.6% in the TAE-MWA group, and 74.6%, 49.2%, and 29.6% in the MWA group, respectively (p = 0.18). The combination therapy of TAE-MWA was significantly superior to MWA monotherapy according to OS in treating HCC within the Milan criteria.

Percutaneous ablation of colorectal liver metastases: a comparison between the outcomes of grayscale US guidance and Sonazoid CEUS Kupffer phase guidance using propensity score matching

PURPOSE

To assess the utility of Sonazoid contrast-enhanced ultrasound (CEUS) for guiding percutaneous microwave ablation (MWA) for colorectal liver metastases (CRLMs).

MATERIALS AND METHODS

The medical records of patients who had undergone ultrasound (US)-guided percutaneous MWA between July 2020 and June 2022, were reviewed. Propensity score matching (PSM) with a ratio of 1:1 was used to balance the potential bias between the grayscale US-guided and Sonazoid CEUS-guided groups. Local tumor progression (LTP), intrahepatic recurrence (IR), and complication rates were compared between the two groups.

RESULTS

Of 252 patients enrolled, 247 achieved complete ablation, and the technical effectiveness was 98.0% (247/252). Of these 247 patients, 158 were in the grayscale US-guided group and 89 in the Sonazoid CEUS-guided group. The median follow-up period was 14.6 months. After PSM, there were no significant differences in LTP, IR, or complication rates between the two groups (p = 0.100, p = 0.511, p > 0.99, respectively). Multivariate analysis identified tumor size ≥ 3 cm (hazard ratio [HR], 7.945; 95% CI, 2.591-24.370; p < 0.001), perivascular (HR, 2.331; 95% CI, 1.068-5.087; p = 0.034), and tumor depth > 8 cm (HR, 3.194; 95% CI, 1.439-7.091; p = 0.004) as significant factors associated with LTP. For tumors with poor vision on grayscale US, Sonazoid CEUS-guided ablation achieved a better LTP rate than grayscale US-guided ablation (3.7% vs.14.8%, p = 0.032).

CONCLUSION

For tumors with poor vision on grayscale US, Sonazoid CEUS guidance is recommended for better local tumor control.

Can the Unipedicular Approach Replace Bipedicular Percutaneous Balloon Kyphoplasty for the Management of Metastatic Vertebral Lesions?

RATIONALE AND OBJECTIVES

To compare the clinical and radiographic results of bipedicular and unipedicular approaches(UPK and BPK) in the management of metastatic vertebral lesions MATERIALS AND METHODS: Eighty-two patients with 159 metastatic vertebral lesions who underwent UPK(25 cases, 69 lesions) or BPK(57 cases, 90 lesions) were retrospectively evaluated. Clinical results were assessed mainly depending on the Visual Analogue Scale(VAS) score, Oswestry Disability Index(ODI) and Quality of Life(QoL). Radiographic outcomes were evaluated primarily on the basis of bone cement distribution and changes in vertebral body height(VBH). Major and minor complications were systematically evaluated and compared to assess the safety of the 2 procedures.

RESULTS

No statistically significant differences were observed in age, sex, types of lesions, location of lesions, posterior vertebral body and/or pedicle involvement, percentage of vertebra invasion between the groups(p=0.17-0.83). The radiographic parameter VBH was similarly improved in both groups(p=0.26-0.93). There was a significant improvement in the clinical parameters VAS score, ODI, and QoL at each follow-up examination compared with the preoperative results(p<0.001). Significant improvement was observed in the VBH at each follow-up point(p<0.05) compared to pre-procedure. UPK was superior to BPK in terms of the operative duration(p<0.001), cement volume(p=0.004), and surgical complications(p=0.04).

CONCLUSION

Both UPK and BPK resulted in similar clinical and radiographic outcomes in patients with metastatic vertebral lesions. The UPK had advantages including a shorter operation and lower cement volume than the BPK, which may have played an important role in reducing the incidence of complications. UPK can replace BPK in the treatment of metastatic vertebral lesions.

The Added Diagnostic Value of Transcatheter CT Hepatic Arteriography for Intraprocedural Detection of Previously Unknown Colorectal Liver Metastases During Percutaneous Ablation and Impact on the Definitive Treatment Plan

PURPOSE

This study assessed the diagnostic value of CT hepatic arteriography (CTHA) for the intraprocedural detection of previously unknown colorectal liver metastases (CRLM) and the impact on the definitive treatment plan.

MATERIALS AND METHODS

All patients treated with CTHA-guided percutaneous ablation for CRLM between January 2012 and March 2022 were identified from the Amsterdam Colorectal Liver Met Registry (AmCORE). Radiology reports of the ablative procedure and follow-up imaging were reviewed to see if (a) previously unknown CRLM were detected intra-procedurally and if (b) new CRLM, potentially missed on CTHA, appeared within 6 months following the procedure; three abdominal radiologists re-reviewed the baseline CTHA scans of these patients with early recurrence. To ratify immediate ablations of concomitantly detected CRLM, the upper limit of false positives was predefined at 10%.

RESULTS

One hundred and fifty-two patients were included. With CTHA, a total of 17 additional tumours in 15 patients were diagnosed and treated immediately, two representing disappeared tumours following systemic chemotherapy. Compared to the conventional contrast-enhanced (ce)CT, ceMRI and 18F-FDG PET-CT, adding CTHA was superior for the detection of CRLM (P < .001). Within 12 months of follow-up 121, new CRLM appeared in 49/152 patients (32.2%); retrospective blinded assessment revealed 56 to already be visible on the baseline CTHA scan (46%); four lesions without substrate on follow-up scans were considered false positives (n = 4/60; 7%). Arterial ring enhancement was the most frequently reported imaging characteristic (n = 45/60; 75%).

CONCLUSION

The subsequent use of CTHA has added value for the detection of previously unknown and vanished CRLM. Taking into account the low number of false positives (7%) and the favourable safety profile of percutaneous ablation, we believe that immediate ablation of typical ring-enhancing supplementary tumours is justified and sufficiently validated.

LEVEL OF EVIDENCE

Level 3; individual cross-sectional study with consistently applied reference standard and blinding.

Multi-Probe RFA vs. Single-Probe MWA in an Ex Vivo Bovine Liver Model: Comparison of Volume and Shape of Coagulation Zones

OBJECTIVES

To compare the volumes and shapes of the coagulation zone (CZ) of a multi-probe RFA system (three RFA electrodes) and a single-probe MWA system from the same vendor in an ex vivo bovine liver model.

MATERIAL & METHODS

A total of 48 CZs were obtained in bovine liver specimens with three different ablation system configurations (single-probe MWA vs. multi-probe RFA with 20 mm inter-probe distance [confluent CZ] vs. multi-probe RFA with 50 mm inter-probe distance [three individual CZs]) at 4, 6, 8, and 10 min ablation time using a fixed ablation protocol. Ablation diameters were measured and ellipticity indices (EIs) and volumes calculated. Calculations for all systems/configurations were compared.

RESULTS

Volumes and diameters increased with ablation time for all configurations. At 4 and 6 min ablation time volumes obtained with the RFA 50 mm setup, and at 8 and 10 min with the RFA 20 mm setup were the largest at 26.5 ± 4.1 mL, 38.1 ± 5.8 mL, 46.3 ± 4.9 mL, 48.4 ± 7.3 mL, respectively. The single-probe MWA could not reach the volumes of the RFA setups for any of the ablation times evaluated. EI were very similar and almost round for RFA 20 mm and single-probe MWA, and differed significantly to the more ovoid ones for the RFA 50 mm configuration.

CONCLUSIONS

The multi-probe RFA system employing three electrodes achieved significantly larger ablation volumes in both configurations (confluent CZ and three individual CZs) per time as compared with a single-probe MWA system in this ex vivo bovine liver model.

Proliferation inhibition and apoptosis of liver cancer cells treated by blue light irradiation

Blue light (BL) irradiation has been a potentially efficient treatment for many kinds of tumors. In this study, a BL irradiation (centered at 453 nm in wavelength) was proposed to treat the common human liver cancer cell lines of SMMC-7721 and HepG2, examined by means of flow cytometry, western blot, fluorescence microscope assay. In comparison to control groups, the apoptosis and proliferation inhibition of both BL-treated cells are expressively enhanced by mitochondrial apoptosis. The mechanism of apoptosis is related to the more production of reactive oxygen species (ROS) induced by BL and the corresponding changes in the expression of apoptosis-related Bcl-2, Bax and Bad proteins. In addition, the migration rate of the cancer cells could be reduced after BL irradiation. These results demonstrate that introducing BL irradiation is helpful to establish an effective and low toxicity strategy for the clinical treatment of liver tumors.

Interventional Treatment Strategies in Intrahepatic Cholangiocarcinoma and Perspectives for Combined Hepatocellular-Cholangiocarcinoma

cHCC-CCA is an uncommon type of liver cancer that exhibits clinical and pathological characteristics of both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), which are the two main forms of primary liver cancer. The similarity to HCC and CCA makes therapeutical strategies challenging. The poor prognosis of CCA in general, as well as for cHCC-CCA, is mainly attributable to the fact that diagnosis is often at an advanced stage of disease. During the last decade, locoregional therapies usually performed by interventional radiologists and its established role in HCC treatment have gained an increasing role in CCA treatment as well. These comprise a wide range of options from tumor ablation procedures such as radiofrequency ablation (RFA), microwave ablation (MWA), computed tomography high-dose rate brachytherapy (CT-HDRBT), and cryoablation to transarterial chemoembolization (TACE), including the option of intra-arterial administration of radioactive spheres (transarterial radioembolization-TARE), and much attention has focused on the potential of individual concepts in recent years. The purpose of this review is to provide an overview of current radiologic interventions for CCA (excluding options for eCCA), to review and appraise the existing literature on the topic, and to provide an outlook on whether such interventions may have a role as treatment for cHCC-CCA in the future.

Immunomodulatory effect of locoregional therapy in the tumor microenvironment

Cancer immunotherapy appears to be a promising treatment option; however, only a subset of patients with cancer responds favorably to treatment. Locoregional therapy initiates a local antitumor immune response by disrupting immunosuppressive components, releasing immunostimulatory damage-associated molecular patterns, recruiting immune effectors, and remodeling the tumor microenvironment. Many studies have shown that locoregional therapy can produce specific antitumor immunity alone; nevertheless, the effect is relatively weak and transient. Furthermore, increasing research efforts have explored the potential synergy between locoregional therapy and immunotherapy to enhance the long-term systemic antitumor immune effect and improve survival. Therefore, further research is needed into the immunomodulatory effects of locoregional therapy and immunotherapy to augment antitumor effects. This review article summarizes the key components of the tumor microenvironment, discusses the immunomodulatory role of locoregional therapy in the tumor microenvironment, and emphasizes the therapeutic potential of locoregional therapy in combination with immune checkpoint inhibitors.

Microwave Ablation of Recurrent Hepatocellular Carcinoma after Curative Surgical Resection

Purpose: To evaluate the efficacy and safety of microwave ablation (MWA) as a treatment for recurrent hepatocellular carcinoma (HCC) after initial successful surgical resection. Methods: This retrospective study included 40 patients (11 women and 29 men; mean age: 62.3 ± 11.7 years) with 48 recurrent lesions of HCC after initial surgical resection that were treated by percutaneous MWA. Several parameters including complications, technical success, local tumor progression (LTP), intrahepatic distant recurrence (IDR), overall survival (OS), and progression-free survival (PFS) were evaluated in order to investigate the safety and efficacy of MWA for these recurrent HCC lesions after surgical treatment. Results: All MWA treatments were performed without complications or procedure-related deaths. Technical success was achieved in all cases. Two cases developed LTP at a rate of 5%, and IDR occurred in 23 cases at a rate of 57.5% (23/40). The 1-, 2-, 3-, 4-, and 6-year OS rates were 97%, 89.2%, 80.3%, 70.2%, and 60.2%, respectively. The 1- and 3-year PFS rates were 50.2% and 34.6%, respectively. Conclusion: MWA is effective and safe as a local treatment for recurrent HCC after initial surgical resection.

Long-term outcomes of combined radiofrequency ablation and multipronged ethanol ablation for the treatment of unfavorable hepatocellular carcinoma

PURPOSE

To evaluate the local efficacy, safety, and long-term outcomes of combined radiofrequency ablation (RFA) and multipronged ethanol ablation (EA) in the treatment of unfavorable hepatocellular carcinoma (HCC) and to determine the prognostic factors for survival.

METHODS

Between August 2009 and December 2017, 98 patients with 110 unfavorable HCC nodules who underwent combined RFA and multipronged EA were retrospectively enrolled in the study. Unfavorable HCC was defined as a medium (3.1-5.0 cm) or large (5.1-7.0 cm) HCC nodule, a tumor located at a high-risk site, or a perivascular tumor. The treatment response, overall survival (OS), and recurrence-free survival (RFS) were analyzed. The Kaplan-Meier method and Cox proportional hazards regression model were used to evaluate the prognostic factors.

RESULTS

Complete ablation was obtained in 80.9% (89/110) of the tumors after initial treatment. Major complications were observed in 3 (3.1%) patients. The cumulative incidence of local tumor progression (LTP) was 23.5% at five years, and no variable was found to be an independent predictive factor for LTP. The five-year OS and RFS rates were 41.9% and 34.0%, respectively. Multivariate analysis showed that the serum alpha-fetoprotein level, tumor size, presence of residual tumor after ablation, and extrahepatic metastases were significant prognostic factors for OS (P = 0.023, P = 0.030, P = 0.001, and P = 0.010, respectively). Tumor type and the number of tumors were predictive factors for RFS (P = 0.029 and P = 0.001, respectively). A perivascular tumor was not an independent predictive factor for OS or RFS.

CONCLUSION

Combined RFA and multipronged EA is a safe and effective treatment for unfavorable HCC, especially for perivascular tumors.

Use of Contrast Media During CT-guided Thermal Ablation of Colorectal Liver Metastasis for Procedure Planning is Associated with Improved Immediate Outcomes

PURPOSE

The aim of this study was to analyze the impact of using intra-procedural pre-ablation contrast-enhanced CT prior to percutaneous thermal ablation (pre-ablation CECT) of colorectal liver metastases (CLM) on local outcomes.

MATERIALS AND METHODS

This retrospective analysis of a prospectively collected liver ablation registry included 144 consecutive patients (median age 57 years IQR [49, 65], 60% men) who underwent 173 CT-guided ablation sessions for 250 CLM between October 2015 and March 2020. In addition to oncologic outcomes, technical success was retrospectively evaluated using a biomechanical deformable image registration software for 3D-minimal ablative margin (3D-MAM) quantification. Bayesian regression was used to estimate effects of pre-ablation CECT on residual unablated tumor, 3D-MAM, and local tumor progression-free survival (LTPFS).

RESULTS

Pre-ablation CECT was acquired in 71/173 (41%) sessions. Residual unablated tumor was present in one (0.9%) versus nine tumors (6.6%) ablated with versus without using pre-ablation CECT, respectively (p = 0.024). Pre-ablation CECT use decreased the odds of residual disease on first follow-up by 78% (CI95% [5, 86]) and incomplete ablation (3D-MAM ≤ 0 mm) by 58% (CI95% [13, 122]). The odds ratio for residual unablated tumor for larger CLM was lower when pre-ablation CECT was used (odds ratio 1.0 with pre-ablation CECT vs. 2.52 without). Pre-ablation CECT use was not associated with improvements on LTPFS.

CONCLUSIONS

Pre-ablation CECT is associated with improved immediate outcomes by significantly reducing the incidence of residual unablated tumor and by mitigating the risk of incomplete ablation for larger CLM. We recommend performing baseline intra-procedural pre-ablation CECT as a standard imaging protocol.

LEVEL OF EVIDENCE

Level 3 (retrospective cohort study).

Percutaneous cryoablation versus partial nephrectomy for cT1b renal tumors: An inverse probability weight analysis

PURPOSE

To investigate differential clinical outcomes in patients treated with partial nephrectomy (PN) vs. percutaneous cryoablation (PCA) for cT1b renal tumors.

MATERIALS AND METHODS

We retrospectively analyzed the records of 119 patients who had undergone PN (n = 90) or PCA (n = 29) for cT1b renal tumors. Inverse probability weighting (IPW) was used for balancing patient demographics, including renal function and tumor complexity. Perioperative complications, renal function preservation rates, and oncological outcomes such as local recurrence-free, metastasis-free, cancer-specific, and overall survival were compared using IPW-adjusted restricted mean survival times (RMSTs).

RESULTS

PCA was more likely to be selected for octogenarians (odds ratio: 11.4, 95% confidence interval [CI]: 3.33-45.1). During the median follow-up of 43 months in the PCA group and 36.5 months in the PN group, unablated local residue or local recurrence was noted in 6 patients in the PCA group and local recurrence was noted in 4 patients in the PN groups. Of the 6 patients in the PCA group, 4 underwent salvage PCA, and local control had been achieved at the last visit. In the IPW-adjusted population, PCA had significantly worse local recurrence-free survival compared with PN (IPW-adjusted RMST difference: -22.7 months, 95% CI: -45.3 to -0.4, P = 0.046). IPW-adjusted RMST for metastasis-free survival (P = 0.23), cancer-specific survival (P = 0.77), and overall survival (P = 0.11) did not differ between PCA and PN. In addition, PN was not a predictor for local control failure at the last visit (odds ratio: 0.30, 95%CI: 0.05-1.29). There were no statistically significant differences between PN and PCA in renal function preservation or overall/severe complication rates.

CONCLUSIONS

In patients with cT1b renal tumor, although the local recurrence rate is higher for PCA than for PN, PCA provides comparable distant oncologic outcomes. PCA can be an alternative treatment option for elderly, comorbid patients, even those with cT1b renal tumors.

Targeted exome-based predictors of patterns of progression of colorectal liver metastasis after percutaneous thermal ablation

BACKGROUND

Percutaneous thermal ablation is a curative-intent locoregional therapy (LRT) for selected patients with unresectable colorectal liver metastasis (CLM). Several factors have been identified that contribute to local tumour control after ablation. However, factors contributing to disease progression outside the ablation zone after ablation are poorly understood.

METHODS

In this retrospective study, using next-generation sequencing, we identified genetic biomarkers associated with different patterns of progression following thermal ablation of CLM.

RESULTS

A total of 191 ablation naïve patients between January 2011 and March 2020 were included in the analysis, and 101 had genomic profiling available. Alterations in the TGFβ pathway were associated with increased risk of development of new intrahepatic tumours (hazard ratio [HR], 2.75, 95% confidence interval [95% CI] 1.39-5.45, P = 0.004); and alterations in the Wnt pathway were associated with increased probability of receiving salvage LRT for any intrahepatic progression (HR, 5.8, 95% CI 1.94-19.5, P = 0.003).

CONCLUSIONS

Our findings indicate that genomic alterations in cancer-related signalling pathways can predict different progression patterns and the likelihood of receiving salvage LRT following percutaneous thermal ablation of CLM.

Comparisons of Radiofrequency Ablation, Microwave Ablation, and Irreversible Electroporation by Using Propensity Score Analysis for Early Stage Hepatocellular Carcinoma

BACKGROUND

Despite the diversity of thermal ablations, such as radiofrequency ablation (RFA) and microwave ablation (MWA), and non-thermal ablation, such as irreversible electroporation (IRE) cross-comparisons of multiple ablative modalities for hepatocellular carcinoma (HCC) treatment remain scarce. Thus, we investigated the therapeutic outcomes of different three ablation modalities in the treatment of early stage HCC.

METHODS

A total of 322 consecutive patients with 366 HCCs (mean tumor size ± standard deviation: 1.7 ± 0.9 cm) who underwent RFA (n = 216, 59.0%), MWA (n = 91, 28.3%), or IRE (n = 15, 4.7%) were included. Local tumor progression (LTP) rates for LTP were compared among the three modalities. Propensity score-matched analysis was used to reduce selection bias.

RESULTS

A significant difference in 2-year LTP rates between the IRE and RFA groups (IRE, 0.0% vs. RFA, 45.0%; p = 0.005) was found. There was no significant difference in 2-year LTP rates between the IRE and MWA groups (IRE, 0.0% vs. MWA, 25.0%; p = 0.103) as well as between the RFA and MWA groups (RFA, 18.2% vs. MWA, 20.6%; p = 0.586).

CONCLUSION

IRE provides better local tumor control than RFA as a first-line therapeutic option for small perivascular HCC.

Radiofrequency versus Ethanol Ablation for Single-Session Treatment of Benign Cystic Thyroid Nodules: A Short-Term Retrospective Study

Objective

This study aims to compare 1-month's efficacy and safety of single-session ethanol ablation and radiofrequency ablation for treating both purely cystic nodules and predominantly cystic thyroid nodules.

Materials and methods

This short-term retrospective study was approved by the Ethics Committee of the Institutional Review Board of Danang Family hospital, and written informed consent for procedures was obtained for all patients. Thirty-nine patients who presented with cystic thyroid nodules and met inclusion criteria were extracted from the computerized medical records. The internal fluid of cystic thyroid nodules was aspirated as much as possible. Ethanol ablation was performed using 18-gauge needles with 99.5% ethanol, and RFA used a cooled-electrode RFA system and 18-gauge internally cooled electrodes via the trans-isthmic approach, moving-shot technique. Nodule volume, therapeutic success rate, the largest diameter, thyroid function tests, and complications were evaluated and compared before and after treatment in each group.

Results

Among 39 patients, 17 patients were undergone EA (mean age of 47.35 years; the proportion of female of 76.5%; purely thyroid cyst percentage of 41.4%) and 22 patients were undergone RFA (mean age of 46.63 years; the proportion of female of 86.4%; purely thyroid cyst percentage of 54.5%). Both treatment techniques showed a significant reduction of the largest diameter and nodule volume (p<0.05) without complications. RFA reduced nodule volume and the largest nodule size greater than EA treatment at 1-month post-ablation (p<0.05). In addition, the therapeutic success rate in the RFA group was higher than in the EA group.

Conclusion

Both RFA and EA treatment with single-session confirm the efficacy and safety for cystic thyroid nodules at 1-month follow-up, RFA reduced greater in nodule volume and the largest nodule size than the EA treatment. Thus, the therapeutic success rate in the RFA group was higher than in the EA group.

Ultrasound-Guided Percutaneous Thermal Ablation of Renal Cancers-In Search for the Ideal Tumour

Over the recent years, the progress in imaging techniques has led to an increased detection of kidney tumours, including small renal masses. While surgery is still the standard of care, there is a growing interest in minimally invasive methods. Ultrasound (US)-guided percutaneous ablation is particularly attractive because it is a safe and relatively simple procedure. In this study, we investigated the success of percutaneous radiofrequency ablation (RFA) in relation to kidney tumour diameter and location. Between August 2016 and September 2021, 253 patients with 259 renal tumours underwent US-guided RFA as a primary treatment in our institution. A total of 67 patients were excluded from this study. Abdominal computed tomography (CT) and tumour biopsy were performed before the procedure. Patients were followed with contrast-enhanced CT, the average follow-up time was 28 months. The studied group was composed of 186 patients with 191 renal tumours-only biopsy-confirmed renal cancers were included. During the follow-up, 46 cases of residual disease and 4 cases of local progression were found. There was a significant correlation between tumour size and the ablation success rate. The success rate was 73.5% and 87.6% for lesions ≤25 mm, 94.6% for lesions ≤25 mm and exophytic, 79.1% for lesions 26-30 mm and 84.4% for lesions 26-30 mm and exophytic, respectively. Four Clavien-Dindo grade ≥2 complications were observed. US-guided percutaneous RFA of T1a renal cancers is safe and well-tolerated. Its effectiveness depends on tumour size, with best results for exophytic lesions smaller than 3 cm. Most of the recurrent or residual tumours can be successfully re-treated with US-guided percutaneous RFA.

Imaging Features of Main Hepatic Resections: The Radiologist Challenging

Liver resection is still the most effective treatment of primary liver malignancies, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), and of metastatic disease, such as colorectal liver metastases. The type of liver resection (anatomic versus non anatomic resection) depends on different features, mainly on the type of malignancy (primary liver neoplasm versus metastatic lesion), size of tumor, its relation with blood and biliary vessels, and the volume of future liver remnant (FLT). Imaging plays a critical role in postoperative assessment, offering the possibility to recognize normal postoperative findings and potential complications. Ultrasonography (US) is the first-line diagnostic tool to use in post-surgical phase. However, computed tomography (CT), due to its comprehensive assessment, allows for a more accurate evaluation and more normal findings than the possible postoperative complications. Magnetic resonance imaging (MRI) with cholangiopancreatography (MRCP) and/or hepatospecific contrast agents remains the best tool for bile duct injuries diagnosis and for ischemic cholangitis evaluation. Consequently, radiologists should be familiar with the surgical approaches for a better comprehension of normal postoperative findings and of postoperative complications.

Nomogram Based on Preoperative Absolute Lymphocyte Count to Predict Local Recurrence in Patients with Non-Small Cell Lung Cancer After Microwave Ablation

Purpose

This study aims to investigate the prognostic value of preoperative absolute lymphocyte count (preALC) for non-small cell lung cancer (NSCLC) after microwave ablation (MWA) and build a combined nomograph with clinical features to predict the local recurrence.

Patients and Methods

A total of 118 NSCLC patients who underwent microwave ablation were enrolled in this study. The median local recurrence-free survival (LRFS) was 35.5 months. Independent prognostic factors obtained by multivariate analysis were included in the prediction model. The prognostic value of the model was assessed by the area under the time-dependent receiver operating characteristic curve (T-AUC).

Results

Histological subtype and preALC were independent risk factors for local relapse-free survival. According to the time-dependent receiver operating characteristic curve (T-ROC), the optimal cut-off value of preALC was 1.965×10⁹/L, the sensitivity was 0.837, and the specificity was 0.594. The area under the T-ROC curve (AUC) of preALC was 0.703. To establish a nomogram to predict the local recurrence rate of NSCLC after MWA based on the prognostic factors revealed by Cox regression.

Conclusion

Preoperative lymphocyte count reduction is associated with poor prognosis of NSCLC. The nomogram model combined with preALC can provide a good individualized prediction of local recurrence after microwave ablation.

A Multi-centre, Single Arm, Non-randomized, Prospective European Trial to Evaluate the Safety and Efficacy of the HistoSonics System in the Treatment of Primary and Metastatic Liver Cancers (#HOPE4LIVER)

PURPOSE

Image-guided thermal ablation are established treatment options for non-surgical patients with primary and metastatic liver cancers. However, there are limitations with nonuniformity of cancer tissue destruction, heat sink effect and the risk of thermal ablative injury. The current non-thermal ablative techniques have high risk of local recurrence and are not widely adopted. Histotripsy is a treatment technology that destroys targeted tissue under ultrasound visualization via mechanical destruction through the precise application of acoustic cavitation and can offer the potential of non-invasive, non-thermal and non-ionizing radiation cancer treatment. The aim of this multi-centre non-randomized phase I/II trial is to assess the initial safety and efficacy of the prototype investigational 'System' in the treatment of primary and metastatic liver cancers.

METHODS/DESIGN

All non-surgical patients with primary/metastatic liver cancers having had previous liver directed therapy, radiation therapy or image-guided ablation may be offered image-guided Histotripsy as per trial protocol. The co-primary endpoints are technical success and procedural safety. Technical success is determined, at ≤ 36 h post procedure, by evaluating the histotripsy treatment size and coverage. The procedural safety is defined by procedure related major complications, defined as Common Terminology Criteria for Adverse Events (CTCAE version 5) grade 3 or higher toxicities, up to 30 days post procedure. This phase I/II trial has intended to recruit up to 45 patients to show safety and efficacy of image-guided histotripsy in liver cancers.

TRAIL REGISTRATION

Clinicaltrials.gov identifier-NCT04573881; NIHR CRN CPMS-ID 47572.

Impact of the Ablative Margin on Local Tumor Progression after Radiofrequency Ablation for Lung Metastases from Colorectal Carcinoma: Supplementary Analysis of a Phase II Trial (MLCSG-0802)

PURPOSE

To explore what extent of ablative margin depicted by computed tomography (CT) immediately after radiofrequency (RF) ablation is required to reduce local tumor progression (LTP) for colorectal cancer (CRC) lung metastases.

MATERIALS AND METHODS

This retrospective study was undertaken as a supplementary analysis of a previous prospective trial. Seventy patients (49 men and 21 women; mean age ± standard deviation, 64.9 years ± 10.6 years) underwent RF ablation for CRC lung metastases, and 95 tumors that were treated in the trial and followed up with CT at least 12 months after RF ablation were evaluated. The mean tumor size was 1.0 cm ± 0.5 cm. The ablative margin was estimated as the shortest distance between the outer edge of the tumor and the surrounding ground-glass opacity on CT obtained immediately after RF ablation. The impact of the ablative margin on LTP was evaluated using logistic regression analysis. Multivariate logistic regression analysis was also performed to identify the risk factors for LTP. The result was validated with multivariate logistic regression applying a bootstrap method (1,000 times resampling).

RESULTS

The mean ablative margin was 2.7 mm ± 1.3 (range, 0.4-7.3 mm). LTP developed in 6 tumors (6%, 6/95) 6-19 months after RF ablation. The LTP rate was significantly higher when the margin was less than 2 mm (P = .023). A margin of <2 mm was also found to be a significant factor for LTP (P = .048) on multivariate analysis and validated using the bootstrap method (P = .025).

CONCLUSIONS

An ablative margin of at least 2 mm is important to reduce LTP after RF ablation for CRC lung metastases.

Outcomes of laser-induced thermotherapy for thyroid nodules at the West Vascular Center, Ukraine

Thyroid nodules are common, occurring in 50-60% of healthy patients. Currently, there are no effective conservative treatment options for nodular goiter, and surgery can have limitations and potential complications. The purpose of this study was to evaluate the efficacy, tolerability, and long-term results of using sclerotherapy and laser-induced interstitial thermotherapy (LITT) to treat benign thyroid nodules. A retrospective analysis was conducted on 456 patients with benign nodular goiter who received LITT. The volume of the nodular goiter was measured at 1, 3, 6, and 12 months post-treatment, and a repeated fine needle aspiration (FNA) with the cytological examination was performed to verify the structure of the nodular goiter in the long term. The results showed that LITT was an effective method for treating nodular mass (nodules), as evidenced by a decrease in the volume of NG by 51-85% after 6-12 months. FNA results 2-3 years after LITT showed no thyrocytes, only connective tissue, indicating the efficacy of LITT for benign thyroid nodules. LITT is highly effective in most cases, often resulting in the disappearance or significant decrease in nodular formations.

Efficacy and safety of single- and multiple-antenna microwave ablation for the treatment of hepatocellular carcinoma and liver metastases: A systematic review and network meta-analysis

BACKGROUND

There is a myriad of microwave ablation (MWA) systems used in clinical settings worldwide for the management of liver cancer that offer a variety of features and capabilities. However, an analysis on which features and capabilities result in the most favorable efficacy and safety results has never been completed due to a lack of head-to-head comparisons. The aim of this study is to compare single-antenna and multiple-antenna MWA using radiofrequency ablation (RFA) as a common comparator in the treatment of very-early, early hepatocellular carcinoma (HCC) and ≤5 cm liver metastases.

METHODS

This network meta-analysis was performed according to PRISMA guidelines. PubMed, Cochrane, and Web of Science databases were searched for comparative studies. Complete ablation (CA) rate, local tumor progression-free (LTPF) rate, overall survival (OS), and major complication rate were assessed. Subgroup analyses were further performed based on synchronous or asynchronous MWA generators and tumor size (<2 cm or ≥2 cm).

RESULTS

Twenty-one studies (3424 patients), including 3 randomized controlled trials (RCTs) and 18 observational studies, met eligibility criteria. For CA, LTPF and major complications, as compared to single-antenna MWA, multiple-antenna MWA had relative risks (RRs) of 1.051 (95% CI: 0.987-1.138), 1.099 (95% CI: 0.991-1.246), and 0.605 (95% CI: 0.193-1.628), respectively. For 1-year and 3-year OS, as compared to single-antenna MWA, multiple-antenna MWA had odds ratios (ORs) of 0.9803 (95% CI: 0.6772-1.449) and 1.046 (95% CI: 0.615-1.851), respectively. Subgroup analysis found synchronized multi-antenna MWA was associated with significantly better LTPF by 22% (RR: 1.22, 95% CI 1.068, 1.421), and 21.4% (RR: 1.214, 95% CI 1.035, 1.449) compared with single-antenna MWA, and asynchronous multiple-antenna MWA, respectively, with more evident differences in larger tumors (≥2 cm).

CONCLUSION

Multi-antenna and single-antenna MWA showed similar effectiveness for local treatment of liver tumors, but synchronous multi-antenna MWA exhibited better LTPF compared to other MWA approaches, particularly for larger liver tumors (≥2 cm). Large-scale RCTs should be further conducted.

Thermal ablation for small renal masses: Identifying the most appropriate tumor size cut-off for predicting perioperative and oncological outcomes

OBJECTIVES

To test TRIFECTA achievement [1) absence of CLAVIEN-DINDO ≥3 complications; 2) complete ablation; 3) absence of ≥30% decrease in eGFR] and local recurrence rates, according to tumor size, in patients treated with thermal ablation (TA: radiofrequency [RFA] and microwave ablation [MWA]) for small renal masses.

METHODS

Retrospective analysis (2008-2020) of 432 patients treated with TA (RFA: 162 vs. MWA: 270). Tumor size was evaluated as: 1) continuously coded variable (cm); 2) tumor size strata (0.1-2 vs. 2.1-3 vs. 3.1-4 vs. >4 cm). Multivariable logistic regression models and a minimum P-value approach were used for testing TRIFECTA achievement. Kaplan-Meier plots depicted local recurrence rates over time.

RESULTS

Overall, 162 (37.5%) vs. 140 (32.4%) vs. 82 (19.0%) vs. 48 (11.1%) patients harboured, respectively, 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm tumors. In multivariable logistic regression models, increasing tumor size was associated with higher rates of no TRIFECTA achievement (OR:1.11; P< 0.001). Using a minimum P-value approach, an optimal tumor size cut-off of 3.2 cm was identified (P< 0.001). In multivariable logistic regression models, 3.1 to 4 cm tumors (OR:1.27; P< 0.001) and >4 cm tumors (OR:1.49; P< 0.001), but not 2.1 to 3 cm tumors (OR:1.05; P= 0.3) were associated with higher rates of no TRIFECTA achievement, relative to 0.1 to 2 cm tumors. The same results were observed in separate analyses of RFA vs. MWA patients. After a median (IQR) follow-up time of 22 (12-44) months, 8 (4.9%), 8 (5.7%), 11 (13.4%), and 5 (10.4%) local recurrences were observed in tumors sized 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm, respectively (P= 0.01).

CONCLUSION

A tumor size cut-off value of ≤3 cm is associated with higher rates of TRIFECTA achievement and lower rates of local recurrence over time in patients treated with TA for small renal masses.

CT-Guided Radiofrequency Thermal Ablation for the Treatment of Atypical, Early-Onset Osteoid Osteoma in Children Younger than 4 Years Old: Single-Institution Experience and Literature Review

The aim of our study is to report our experience on CT-guided radiofrequency ablation (RFA) for osteoid osteoma (OO) in children under 4 years of age and to review the literature regarding this atypical, early onset of the disease. We retrospectively reviewed the clinical and radiological records of the patients treated with CT-guided RFA for OO at our institution (2006−2021), including those under 4 years of age. Data regarding technical success, clinical success, and biopsy diagnostic yield were collected. Moreover, we performed a literature review including previous articles on early-onset OO. We found only 12 patients that were under 4 years of age (12/842−1.4%) at the time of RFA treatment: 4 F and 8 M, mean age at the time of the treatment 35.3 months (range 22−46 months). The mean follow-up was 22.8 months (range 6−96 months). Technical success was achieved in all cases (12/12). In all patients (12/12), a complete remission of the pain symptoms was achieved at clinical follow-up controls. No recurrence of pain or complications were documented. The histopathological diagnosis was confirmed in 4 patients (4/12−33.3%). Moreover, we found another 9 articles in the literature with a main focus on early-onset OO (<4 years old), with a total of 12 patients included; 6 of those patients (6/12−50%) were treated with CT-guided RFA, with success reported 5 cases (5/6−83.3%). Our series of cases treated at a single institution, together with the existing data from the literature, confirms that CT-guided RFA is effective and safe for the treatment of osteoid osteoma, even in atypical, early onset in children under 4 years of age.

Percutaneous Thermal Ablation for Managing Small Renal Metastatic Tumors

PURPOSE

To retrospectively evaluate the treatment outcomes of thermal ablation for renal metastatic tumors.

MATERIALS AND METHODS

Thirteen consecutive patients with small renal metastatic tumors (≤3 cm), who underwent thermal ablation between 2009 and 2020, were included in this study. Eight patients had extra-renal tumors during renal ablation. The primary tumors were adenoid cystic carcinoma in four patients, lung cancer in three, hemangiopericytoma in three, leiomyosarcoma in two, and thyroid cancer in one. The therapeutic effects, safety, survival rate, prognostic factor, and renal function were evaluated.

RESULTS

We performed 18 ablation sessions (cryoablation, n = 13; radiofrequency ablation, n = 5) on 19 renal metastases with a mean diameter of 1.7 cm, which resulted in a primary technique efficacy rate of 100% without procedure-related deaths or major complications. Renal function significantly declined 6 months after ablation (P = 0.0039). During the mean follow-up period of 31.2 ± 22.4 months (range, 2.7-71.4 months), one patient had local tumor progression at 11.9 months following radiofrequency ablation. The overall survival rates at 1 and 3 years after ablation were 76.9% (95% confidence interval [CI], 54.0%-99.8%) and 59.3% (95% CI, 31.3%-87.3%), respectively. Tumor size ≥ 2 cm (P = 0.02) and metastasis from non-small cell lung cancer (P = 0.001) were significant worse prognostic factors in univariate analysis, and metastasis from non-small cell lung cancer (P = 0.01) was significant in multivariate analysis.

CONCLUSIONS

Percutaneous thermal ablation for small renal metastases is safe and feasible and can control local tumors.

Imaging and histological features of tumor biopsy sample predict aggressive intrasegmental recurrence of hepatocellular carcinoma after radiofrequency ablation

Aggressive intrasegmental recurrence (AIR) is a form of local recurrence associated with a dismal prognosis and defined by multiple nodules or by an infiltrative mass with a tumor thrombus, occurring in the treated segment, after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). We aimed to identify radiological and/or histological characteristics of tumor biopsy predictive of AIR. We retrospectively analyzed patients treated by No-Touch multi-bipolar RFA (mbpRFA) for a first HCC with a systematic per-procedural tumor biopsy positive for diagnosis of HCC. The first recurrence was classified as non-aggressive local recurrence, AIR or intrahepatic distant recurrence. 212 patients were included (168 men; mean age 67.1 years; mean tumor size 28.6 mm, 181 cirrhosis). AIR occurred in 21/212 patients (10%) and was associated with a higher risk of death (57% in patients with AIR vs 30% without AIR, p = 0.0001). Non-smooth tumor margins, observed in 21% of the patients and macro-trabecular massive histological subtype, observed in 12% of the patients were independently related to a higher risk of AIR (HR: 3.7[1.57;9.06], p = 0.002 and HR:3.8[2.47;10], p = 0.005 respectively). Non smooth margins at imaging and macro-trabecular massive histological subtype are associated with AIR and could be considered as aggressive features useful to stratify therapeutic strategy.

Percutaneous image-guided cryoablation with temporary balloon occlusion of the renal artery for the treatment of central renal tumors

PURPOSE

The purpose of this study was to report the technical feasibility and outcomes of percutaneous image-guided cryoablation with temporary balloon occlusion of the renal artery for the treatment of central renal tumors.

MATERIALS AND METHODS

All consecutive patients with central renal tumors treated with cryoablation and temporary renal artery occlusion from January 2017 to October 2021 were retrospectively included. Patient demographics, tumor's characteristics, procedural data, technical success, primary and secondary clinical efficacy, complications (according to Cardiovascular and Interventional Radiology Society of Europe [CIRSE] classification) and follow-up were investigated.

RESULTS

A total of 14 patients (8 men, 6 women; mean age 72.4 years ± 21.4 [SD] years; age range: 42-93 years) with 14 central renal tumors (median size, 32 mm; IQR: 23.5, 39.5 mm; range: 13-50 mm) were treated with percutaneous image-guided cryoablation and temporary balloon occlusion of the renal artery. Technical success was 13/14 (93%), with 1/14 (7%) failure of vascular access. A median of 4 cryoprobes (IQR: 3, 4.75) were inserted and protective hydrodissection was performed in 11/14 (79%) patients. Median time to perform cryoprobes insertion, hydrodissection and vascular access was 26.5 min (IQR: 18, 35 min), 10 min (IQR: 10, 17 min) and 30 min (IQR: 20, 45 min) respectively. Median duration of the whole intervention was 150 min (IQR: 129, 180 min; range: 100-270 min). Median hospital stay was 2.5 days (IQR: 2, 4 days; range: 2-14 days). Major complications occurred in 3/14 (21%) patients. Primary efficacy rate was 93% (13/14 patients). Median oncological follow-up was 25 months (IQR: 11, 33 months; range: 6-39 months). One patient experienced renal tumor recurrence at 14-months of follow-up, which was successfully treated with repeat cryoablation.

CONCLUSION

Percutaneous image-guided cryoablation of renal tumors with temporary balloon occlusion of the renal artery is technically feasible, with a high technical success rate and paths the way for percutaneous treatment of central renal tumors.

Ultrasound-guided percutaneous irrigation of calcific tendinopathy outside the rotator cuff: short-term evaluation

RATIONALE AND OBJECTIVES

While ultrasound-guided percutaneous irrigation for painful calcific tendinopathy (US-PICT) is the treatment of choice for the rotator cuff, there is a lack of knowledge regarding the treatment of this condition with atypical location. The purpose of our study is to assess if US-PICT can be applied safely and successfully in atypical sites, outside of the rotator cuff.

MATERIALS AND METHODS

We retrospectively reviewed the US-PICT performed outside the rotator cuff, in the last 5 years in a single institution. A total of 16 patients have been included in this study. We collected the values of the numerical rating scale (NRS) for pain pre- and post-procedure (7 days and 3-month follow-up). Moreover, we assessed the imaging studies available pre- and post-procedure (ultrasound and plain radiography) to assess complications.

RESULTS

In all the 16 patients (10F, 6 M; mean age 50.2; range 24-65-year-old), no complications have been observed during and after the procedures. The mean pain NRS before treatment was 8.7 (range 10-6) and dropped to 1.1 (6-0) after 1 week as well after 3 months 1.1 (6-0). The NRS pain reduction from baseline resulted to be statistically significant after 7 days and 3 months (p < 0.001).

CONCLUSION

Our results suggest the safety and efficacy of this procedure, underlining the great potential of US-PICT applied even in different atypical locations.

Cryptococcus granuloma mimicking local progressed tumor after cryoablation of renal cell carcinoma: A case report

Infectious granulomas arising in the kidney are rare. However, there are few reports regarding renal granulomas, such as xanthogranulomatous pyelonephritis, sarcoidosis, malakoplakia, and tuberculosis. Here, we report a case of cryptococcal granuloma resembling a locally progressed tumor after percutaneous cryotherapy for renal cell carcinoma. A male patient in his 80s with rheumatoid arthritis underwent computed tomography (CT)-guided cryoablation for biopsy-proven papillary renal cell carcinoma. Follow-up contrast-enhanced CT imaging obtained 4 months after ablation confirmed an enhanced mass on the edge of the ablation zone. There were no symptoms related to the mass. This mass was radiologically diagnosed as local tumor progression and treated with repeated cryoablation. Percutaneous biopsy of the mass was performed immediately after the second cryoablation, and the mass was pathologically diagnosed as granuloma related to Cryptococcus infection. The patient was administered antifungal fluconazole for 1 year with a good outcome.

The influence of diverse bone cement distribution patterns for metastatic vertebral lesions after bilateral percutaneous kyphoplasty

Objective

To investigate the influence of diverse bone cement distribution patterns in patients with metastatic vertebral lesions after bilateral percutaneous kyphoplasty (PKP).

Methods

Fifty-nine patients with single-level metastatic vertebral lesions who received bilateral PKP were retrospectively reviewed. According to the different bone cement distribution patterns, patients were divided into confluent (n = 35, CF) and separated (n = 24, SP) groups. Indicators including visual analogue scale (VAS), Oswestry Disability Index (ODI), vertebral body height (VBH) variation, quality of life (QoL), and related complications were reviewed and compared between the two groups.

Results

No statistically significant differences were observed between the two groups in age, sex, types of lesions, locations of lesions, posterior vertebral body and/or pedicle involvement, percentage of vertebral invasion, procedure duration or cement volume (p > 0.05). There was significant improvement in VAS, ODI, VBH and QoL at any follow-up examination (p < 0.05) compared with those preoperatively. The CF group exhibited better pain relief in VAS scores than did the SP group just at 3 days and 1 month after PKP (p < 0.05). There were no significant differences between the two groups in VAS scores at 3 months or 1 year after PKP (p > 0.05). No statistically significant differences were observed between the two groups in terms of ODI, VBH or QoL (p > 0.05). There was no statistically significant difference in the incidence of complications between the two groups (p > 0.05).

Conclusions

More rapid pain relief was achieved with confluent rather than separated bone cement distribution patterns in PKP for patients with metastatic vertebral lesions.

Differential efficacy of ablation therapy versus partial nephrectomy between clinical T1a and T1b renal tumors: A systematic review and meta-analysis

PURPOSE

To assess the differential clinical outcomes of patients treated with partial nephrectomy (PN) vs. those treated with ablation therapy (AT) such as radiofrequency ablation, cryoablation and microwave ablation for cT1b compared to cT1a renal tumors.

MATERIALS AND METHODS

Multiple databases were searched for articles published before August 2021. Studies were deemed eligible if they compared clinical outcomes in patients who underwent PN with those who underwent AT for cT1a and/or cT1b renal tumors.

RESULTS

Overall, 27 studies comprising 13,996 patients were eligible for this meta-analysis. In both cT1a and cT1b renal tumors, there was no significant difference in the percent decline of estimated glomerular filtration rates or in the overall/severe complication rates between PN and AT. Compared to AT, PN was associated with a lower risk of local recurrence in both patients with cT1a and cT1b tumors (cT1a: pooled risk ratio [RR]; 0.43, 95% confidence intervals [CI]; 0.28-0.66, cT1b: pooled RR; 0.41, 95%CI; 0.23-0.75). Subgroup analyses regarding the technical approach revealed no statistical difference in local recurrence rates between percutaneous AT and PN in patients with cT1a tumors (pooled RR; 0.61, 95%CI; 0.32-1.15). In cT1b, however, PN was associated with a lower risk of local recurrence (pooled RR; 0.45, 95%CI; 0.23-0.88). There was no difference in distant metastasis or cancer mortality rates between PN and AT in patients with cT1a, or cT1b tumors.

CONCLUSIONS

AT has a substantially relevant disadvantage with regards to local recurrence compared to PN, particularly in cT1b renal tumors. Despite the limitations inherent to the nature of retrospective and unmatched primary cohorts, percutaneous AT could be used as a reasonable alternative treatment for well-selected patients with cT1a renal tumors.

Stereotactic radiofrequency ablation as a valid first-line treatment option for hepatocellular adenomas

OBJECTIVES

This study aimed to assess the safety and efficacy of stereotactic radiofrequency ablation (SRFA) in patients with hepatocellular adenomas (HCA).

METHODS

Retrospective analyses of all patients referred for SRFA treatment at our institution between January 2010 and October 2020 revealed 14 patients (10 women; mean age 34.4 [range, 17-73 years]) with 38 HCAs treated through 18 ablation sessions. Ablations were considered successful if a safety margin >5 mm was achieved. Demographic, interventional, and outcome data were collected and analyzed. Primary and secondary technical efficacy rates were assessed based on follow-up images consisting of contrast-enhanced CT or MR scans.

RESULTS

The mean tumor size was 22 mm (range, 7-75 mm). Overall, 37/38 (97.4%) tumors were successfully ablated at the initial SRFA (primary efficacy rate of 97.4%). The median follow-up duration was 49.6 months. No deaths or adenoma-related complications (hemorrhage or malignant transformation) were observed. Disease-free survival rates at 1, 3, and 5 years from the date of the first SRFA were 100%, 85.8%, and 85.8%, respectively. Two patients developed new distant tumors retreated with consecutive re-ablation. No major complications occurred during any of the 18 ablation sessions.

CONCLUSIONS

Percutaneous thermal ablation is efficient in the treatment of HCAs and may thus be considered a valid first-line treatment option. In addition, SRFA allows for an effective, minimally invasive treatment of large and multiple hepatic tumors within one session.

Complications Risk Assessment and Imaging Findings of Thermal Ablation Treatment in Liver Cancers: What the Radiologist Should Expect

One of the major fields of application of ablation treatment is liver tumors. With respect to HCC, ablation treatments are considered as upfront treatments in patients with early-stage disease, while in colorectal liver metastases (CLM), they can be employed as an upfront treatment or in association with surgical resection. The main prognostic feature of ablation is the tumor size, since the goal of the treatment is the necrosis of all viable tumor tissue with an adequate tumor-free margin. Radiofrequency ablation (RFA) and microwave ablation (MWA) are the most employed ablation techniques. Ablation therapies in HCC and liver metastases have presented a challenge to radiologists, who need to assess response to determine complication-related treatment. Complications, defined as any unexpected variation from a procedural course, and adverse events, defined as any actual or potential injury related to the treatment, could occur either during the procedure or afterwards. To date, RFA and MWA have shown no statistically significant differences in mortality rates or major or minor complications. To reduce the rate of major complications, patient selection and risk assessment are essential. To determine the right cost-benefit ratio for the ablation method to be used, it is necessary to identify patients at high risk of infections, coagulation disorders and previous abdominal surgery interventions. Based on risk assessment, during the procedure as part of surveillance, the radiologists should pay attention to several complications, such as vascular, biliary, mechanical and infectious. Multiphase CT is an imaging tool chosen in emergency settings. The radiologist should report technical success, treatment efficacy, and complications. The complications should be assessed according to well-defined classification systems, and these complications should be categorized consistently according to severity and time of occurrence.