The Diagnosis and Staging of Hepatocellular Carcinoma: A Review of Current Practices

Promoting the early detection and diagnosis of hepatocellular carcinoma (HCC) is a critical strategy to improve patient outcomes as this can lead to greater access to curative treatments. This review highlights the diagnostic tests for HCC, including the use of the Liver Imaging Reporting and Data System systems and histopathology. Staging is essential for informing prognosis and guiding treatment decisions; this review also covers a widely used and well-validated staging system called the Barcelona-Clinic Liver Cancer (BCLC) algorithm. The BCLC incorporates tumor status, liver function, and patient performance to stage patients with newly diagnosed HCC.

Diagnostic performance of contrast-enhanced ultrasound in traumatic solid organ injuries in children: a systematic review and meta-analysis

BACKGROUND

Blunt abdominal trauma (BAT) is a significant contributor to pediatric mortality, often causing liver and spleen injuries. Contrast-enhanced computed tomography (CT), the gold standard for diagnosing solid organ injury, poses radiation risks to children. Contrast-enhanced ultrasound (CEUS) may be a promising alternative imaging modality.

OBJECTIVES

To evaluate the diagnostic utility of CEUS for detecting solid organ injuries following BAT in the pediatric population.

METHODS

A systematic review and meta-analysis were conducted through a thorough literature search in PubMed, Scopus, Web of Science, and Embase databases up to October 1, 2023. Diagnostic accuracy metrics were aggregated using a bivariate model, and subgroup meta-analysis compared CEUS accuracy across various organs.

RESULTS

Meta-analysis from four studies, including 364 pediatric patients, revealed a pooled sensitivity of 88.5% (95%CI 82.5-92.6%) and specificity of 98.5% (95%CI 94.9-99.6%), with an area under the curve of 96% (95%CI 88 - 99%). Splenic injuries showed higher sensitivity than liver injuries (P-value < 0.01), while kidney assessments demonstrated higher specificity (P-value < 0.05).

CONCLUSION

This study highlights the diagnostic potential of CEUS for pediatric solid organ injuries caused by BAT. Further large-scale studies are needed due to the limited number and sample size of the included studies.

The role of microwave ablation in combination with surgery in the management of multiple high-risk pulmonary nodules

AIM

To evaluate the feasibility and safety of surgical resection combined with microwave ablation (MWA) for patients with multiple high-risk pulmonary nodules.

MATERIALS AND METHODS

From September 2010 to November 2023, a total of 166 early multiple high-risk pulmonary nodule patients in our institution were retrospectively analyzed. Fifty-three patients who underwent surgical resection in combination with MWA were considered as the observation group, and 113 patients who underwent two operations or one operation to remove nodules in two lobes of the lungs were considered as the control group. The primary endpoint was postoperative progression-free survival (PFS). Secondary endpoints were lung function, postoperative complications, and length and cost of hospitalization.

RESULTS

In the observation group, the median PFS was 37 months (1-63 months), 9 patients (16.98%) had postoperative recurrence, and the 1-year and 3-year PFS rates were 97.6% and 89.0%, respectively. In the control group, the median PFS was 36 months (1-56 months), 10 patients (8.84%) had postoperative recurrence, and the 1-year and 3-year PFS rates were 99% and 97.8%, respectively. The difference between the two groups was not statistically significant (P = 0.392). Lung function measurements showed a decrease in patients after surgery (P<0.05), and no significant change in patients after MWA (P > 0.05). Compared with two surgical resections, the combined treatment required less hospitalization and cost (P < 0.05).

CONCLUSION

For patients with multiple high-risk pulmonary nodules, surgical resection in combination with microwave ablation is an effective and safe treatment, which has less hospitalization and cost than using surgical resection alone.

Navigated Intraoperative Ultrasound Offers Effective and Efficient Real-Time Analysis of Intracranial Tumor Resection and Brain Shift

BACKGROUND AND OBJECTIVES

Neuronavigation is a fundamental tool in the resection of intracranial tumors. However, it is limited by its calibration to preoperative neuroimaging, which loses accuracy intraoperatively after brain shift. Therefore, surgeons rely on anatomic landmarks or tools like intraoperative MRI to assess the extent of tumor resection (EOR) and update neuronavigation. Recent studies demonstrate that intraoperative ultrasound (iUS) provides point-of-care imaging without the cost or resource utilization of an intraoperative MRI, and advances in neuronavigation-guided iUS provide an opportunity for real-time imaging overlaid with neuronavigation to account for brain shift. We assessed the feasibility, efficacy, and benefits of navigated iUS to assess the EOR and restore stereotactic accuracy in neuronavigation after brain shift.

METHODS

This prospective single-center study included patients presenting with intracranial tumors (gliomas, metastasis) to an academic medical center. Navigated iUS images were acquired preresection, midresection, and postresection. The EOR was determined by the surgeon intraoperatively and compared with the postoperative MRI report by an independent neuroradiologist. Outcome measures included time to perform the iUS sweep, time to process ultrasound images, and EOR predicted by the surgeon intraoperatively compared with the postoperative MRI.

RESULTS

This study included 40 patients consisting of gliomas (n = 18 high-grade gliomas, n = 4 low-grade gliomas, n = 4 recurrent) and metastasis (n = 18). Navigated ultrasound sweeps were performed in all patients (n = 83) with a median time to perform of 5.5 seconds and a median image processing time of 29.9 seconds. There was 95% concordance between the surgeon's and neuroradiologist's determination of EOR using navigated iUS and postoperative MRI, respectively. The sensitivity was 100%, and the specificity was 94%.

CONCLUSION

Navigated iUS was successfully used for EOR determination in glioma and metastasis resection. Incorporating navigated iUS into the surgical workflow is safe and efficient and provides a real-time assessment of EOR while accounting for brain shift in intracranial tumor surgeries.

Hepatocellular carcinoma: updates on epidemiology, surveillance, diagnosis and treatment

Hepatocellular carcinoma (HCC) is a major global burden, ranking as the third leading cause of cancer-related mortality. HCC due to chronic hepatitis B virus (HBV) or C virus (HCV) infection has decreased due to universal vaccination for HBV and effective antiviral therapy for both HBV and HCV, but HCC related to metabolic dysfunction-associated steatotic liver disease and alcohol-associated liver disease is increasing. Biannual liver ultrasonography and serum α-fetoprotein are the primary surveillance tools for early HCC detection among high-risk patients (e.g., cirrhosis, chronic HBV). Alternative surveillance tools such as blood-based biomarker panels and abbreviated magnetic resonance imaging (MRI) are being investigated. Multiphasic computed tomography or MRI is the standard for HCC diagnosis, but histological confirmation should be considered, especially when inconclusive findings are seen on cross-sectional imaging. Staging and treatment decisions are complex and should be made in multidisciplinary settings, incorporating multiple factors including tumor burden, degree of liver dysfunction, patient performance status, available expertise, and patient preferences. Early-stage HCC is best treated with curative options such as resection, ablation, or transplantation. For intermediate-stage disease, locoregional therapies are primarily recommended although systemic therapies may be preferred for patients with large intrahepatic tumor burden. In advanced-stage disease, immune checkpoint inhibitor-based therapy is the preferred treatment regimen. In this review article, we discuss the recent global epidemiology, risk factors, and HCC care continuum encompassing surveillance, diagnosis, staging, and treatments.

Radiofrequency Ablation of Low-Risk Papillary Thyroid Microcarcinoma: A Retrospective Cohort Study Including Patients with More than 10 Years of Follow-up

Background: The longest reported follow-up for thermal ablation of papillary thyroid microcarcinoma (PTMC) is 5 years. We evaluated the long-term efficacy and safety of radiofrequency ablation (RFA) in patients with low-risk PTMC with clinical follow-up of more than 10 years. Methods: In this retrospective cohort study, we included patients with low-risk PTMC who had more than 10 years of follow-up after ultrasound (US)-guided RFA (performed between May 2008 and December 2013). Sixty-five consecutive patients with 71 low-risk PTMCs who were unsuitable for surgery or declined surgery were included. Before RFA, all patients underwent US and thyroid computerized tomography. Repeat RFA for staged ablation was performed when the first RFA did not secure sufficient safety margins because of the tumor closely abutting the recurrent laryngeal nerve. Follow-up US imaging was performed at 1 week, 3 months, 6 months, every 6 months until 2 years, and then annually afterward. Primary outcomes were the respective cumulative rates of disease progression (defined by local tumor progression, lymph node, or distant metastasis), newly developed thyroid cancer, and conversion surgery. Secondary outcomes were serial volume reduction rate (VRR), complete disappearance rate of ablated PTMC, and adverse events associated with procedures. Results: Of 65 patients included in the study, 60 had unifocal and 5 had multifocal PTMCs. The mean number of RFA sessions per tumor was 1.2, and the median follow-up duration was 151 months (interquartile ranges, 131-157). Twenty percent (13/65) of patients required repeat RFA. There were no cases of disease progression. Five patients (5/65, 7.7%) developed a new papillary thyroid cancer (four treated with RFA and one with lobectomy). At 24 months, the mean VRR was 100%, and this was maintained throughout the final follow-up. The complete tumor disappearance rates after one or more RFA treatments were 40.8% (29/71), 74.6% (53/71), and 100% (71/71) at 6, 12, and 24 months, respectively. One major (subclinical hypothyroidism) and three minor adverse events occurred. Conclusions: In our experience, RFA of low-risk PTMC is effective and safe. During more than 10 years of follow-up, we observed no incident local tumor progression nor metastases, but 7.7% of patients developed a new papillary thyroid cancer.

The Relationship Between Rim-like Enhancement on Pre-ablation Contrast-enhanced Ultrasound of Colorectal Liver Metastasis and Early Intrahepatic Progression After Thermal Ablation: A Preliminary Study

OBJECTIVE

To investigate the relationship between the rim-like enhancement pattern on pre-ablation contrast-enhanced ultrasound (CEUS) of colorectal liver metastasis (CRLM) and the therapeutic efficacy of percutaneous microwave ablation (MWA).

METHODS

Patients with CRLM underwent MWA and were evaluated using CEUS before ablation in our hospital between February 2020 and February 2023 were enrolled in this retrospective study. The enhancement patterns of CRLM were assessed by two radiologists and classified as rim-like enhancement and non-rim-like enhancement patterns. The therapeutic outcomes, including cumulative intrahepatic progression rate and early intrahepatic progression rate, were followed up and analyzed.

RESULTS

Overall, 50 patients with 121 nodules were enrolled. Rim-like enhancement pattern was observed in 18 patients (18/50, 36.0%). The cumulative intrahepatic progression rate was significantly higher in the rim-like enhancement group than the rate in the non-rim-like enhancement group (p = 0.022). The early intrahepatic progression rate in the rim-like enhancement group was also significantly higher than the rate in the non-rim-like enhancement group (12/17, 70.6% vs. 6/24, 25.0%, p = 0.005). The multivariable analysis demonstrated that the rim-like enhancement pattern of CRLM was a significant risk factor associated with early intrahepatic progression after MWA (p = 0.013).

CONCLUSION

Rim-like enhancement pattern on pre-ablation CEUS of CRLM was associated with a higher risk of intrahepatic progression after MWA.

Limited Effectiveness in Early Human Clinical Experience with Pulsed Electrical Field Ablation

PURPOSE

To evaluate oncological outcomes, abscopal effect, and adverse events (AEs) of pulsed electrical field (PEF) ablation of tumors in the chest, abdomen, and pelvis.

MATERIALS AND METHODS

PEF ablations performed at an academic medical center between May 2023 and January 2024 were retrospectively analyzed. Eleven patients (4 males and 7 females; age, 58 years ± 19) underwent 11 PEF sessions targeting 13 tumors (lung metastasis from solitary fibrous tumor [n = 3] and colorectal carcinoma (CA) [n = 1], osteosarcoma pleural metastases [n = 2], hepatocellular CA [n = 2], liver metastasis from colorectal CA [n = 1] and leiomyosarcoma [n = 1], metastatic melanoma to the pancreas [n = 1], metastatic retroperitoneal lymph node from endometrial CA [n = 1], and recurrence of endometrial CA in the vaginal cuff [n = 1]) with the goal of complete coverage (n = 11/13) or debulking (n = 2/13). The mean tumor diameter was 1.9 cm (SD ± 1.0; range, 0.4-3.3 cm). Cross-sectional imaging follow-up was 5.3 months (SD ± 2.2; range, 1.9-7.9 months). Oncological outcomes, abscopal effect, and AEs categorized according to the Society of Interventional Radiology (SIR) guidelines were analyzed.

RESULTS

Of 11 tumors that underwent ablation for complete coverage, complete coverage was achieved for 1 (9%), and residual was detected in 9 (81%). Ten (91%) of 11 patients showed either residual, local, or distant progression within a median of 3 months. No abscopal effect was observed. There were 2 mild and 2 severe AEs.

CONCLUSIONS

PEF ablation showed a low rate of complete coverage (9%) and a high rate (91%) of residual, local, or distant progression. No abscopal effect was observed in any patient within a median of 5.1 months after the ablation.

Ablative techniques in colorectal liver metastases: A systematic review, descriptive summary of practice, and recommendations for optimal data reporting

BACKGROUND

Radiofrequency Ablation (RFA) and Microwave Ablation (MWA) are alternative treatments for colorectal liver metastasis (CRLM) patients that are unsuitable for resection. However, consensus is lacking regarding selection criteria, tumour characteristics, ablation technique delivery, and device settings. This study aims to summarise current evidence to inform future prospective studies.

METHODS

A systematic review was conducted following PRISMA guidelines. Studies assessing RFA and MWA treatment of CRLM were identified in Medline, Embase, Web of Science and the Cochrane database of systematic reviews, from inception until 31st August 2024.

RESULTS

Fifty-two studies were included (retrospective cohort n = 45, prospective cohort n = 5, non-randomized comparative studies n = 2). Fifty-four inclusion criteria were used across 45 studies and were not stated in 7 studies. Tumours varied in mean number [1-8] and diameter (1.54-4.35 cm). Neoadjuvant chemotherapy use (10-100 % of patients), ablation delivery approach (open n = 4, laparoscopic n = 11, percutaneous n = 26, mixed n = 5), anaesthetic mode (GA n = 18, LA n = 11, mixed n = 2) and delivering clinician (radiologist n = 11, surgeon n = 16, both n = 1) all varied. Thirty-two studies lacked complete ablation device settings. Six studies followed a standardized ablation algorithm and 14 studies had specific settings. Five-year survival ranged from 0 to 69.7 % for ablation.

CONCLUSIONS

There is significant heterogeneity in the reporting of study design, patient selection, and ablation techniques for CRLM. The lack of standardized approaches and inconsistent reporting of methodology and outcomes make it challenging to determine the optimal ablative treatment for CRLM. We recommend that future research should focus on clearly defining selection and treatment criteria, as well as treatment delivery.

US & MR/CT Image Fusion with Markerless Skin Registration: A Proof of Concept

This paper presents an innovative automatic fusion imaging system that combines 3D CT/MR images with real-time ultrasound acquisition. The system eliminates the need for external physical markers and complex training, making image fusion feasible for physicians with different experience levels. The integrated system involves a portable 3D camera for patient-specific surface acquisition, an electromagnetic tracking system, and US components. The fusion algorithm comprises two main parts: skin segmentation and rigid co-registration, both integrated into the US machine. The co-registration aligns the surface extracted from CT/MR images with the 3D surface acquired by the camera, facilitating rapid and effective fusion. Experimental tests in different settings, validate the system's accuracy, computational efficiency, noise robustness, and operator independence.

Efficacy and Oncologic Outcomes of Thermal Ablation Techniques in the Treatment of Primary Low-Risk Papillary Thyroid Carcinoma: A Systematic Review and Network Meta-Analysis

BACKGROUND

This study aimed to evaluate the safety, efficacy, and oncologic outcomes of thermal ablation techniques, including radiofrequency, laser, and microwave ablation, in treating primary thyroid cancer compared with surgical resection.

METHOD

We conducted a systematic review and network meta-analysis, which included 21 comparative studies and 40 noncomparative studies.

RESULTS

The three thermal ablation techniques showed significant superiority over surgical resection in terms of operative time, pain, cost, quality of life, and complications. Three years after the procedure, the tumor volume reduction and complete disappearance rates for the three thermal ablation techniques were similar, at approximately 99% and 93%-95%, respectively. The recurrence rate remained comparable (approximately 2%-3%) among the three thermal ablation techniques and surgical resection during a follow-up period exceeding 3 years.

CONCLUSIONS

The safety, efficacy, and oncologic outcomes of thermal ablation techniques may be acceptable and comparable to surgical resection for selected cases of primary thyroid cancer.

Preclinical testing of a new radiofrequency ablation device in a porcine perianal fistula model

PURPOSE

Anorectal fistulas present a treatment challenge, with conventional surgical methods potentially resulting in complications such as fecal incontinence. To improve patient outcomes, more effective and minimally invasive therapies are critically needed. In this study, an optimal porcine model for the creation of anorectal fistulas was developed and used to evaluate the efficacy of radiofrequency ablation (RFA) therapy.

METHODS

Two distinct but related experiments were conducted. In the first experiment, a reliable and standardized porcine anorectal fistula model was developed. In the second, the healing process was assessed, and outcomes were compared between the RFA-treated group and the control group using the established porcine model.

RESULTS

The results indicated that a 3.5-cm fistula tract length and a 14-day evaluation period following seton removal are optimal for the porcine anorectal fistula model. In the second experiment, the RFA group tended to exhibit better outcomes regarding fistula closure, although the differences were not statistically significant. Histopathologically, no significant difference in inflammation grade was observed between groups; however, scar tissue was more predominant in the RFA group.

CONCLUSIONS

The findings suggest that RFA therapy may offer potential benefits in the treatment of anorectal fistulas, as demonstrated using a porcine model. To validate these results and explore the mechanisms of action underlying RFA therapy for anorectal fistulas, further research involving larger sample sizes and a more robust study design is required.

Safety and effectiveness of balloon catheter-assisted ultrasound-guided percutaneous microwave ablation in difficult-site liver cancer

BACKGROUND

Balloon catheter isolation is a promising auxiliary method for thermal ablation treatment of liver cancer. We aimed to explore the safety and effectiveness of balloon catheter isolation-assisted ultrasound-guided percutaneous microwave ablation (MWA) in treating liver cancer in difficult anatomical locations.

METHODS

Data of 132 patients with 145 difficult-site liver cancer treated with ultrasound-guided percutaneous MWA were retrospectively analyzed. Participants were classified into the isolation (n = 40) and non-isolation (n = 92) groups based on whether the patients were treated using a balloon catheter prior to ablation. The major complication rates, local tumor residuals (LTR), and tumor follow-up for local tumor progression (LTP) at 6 and 12 months post-ablation were compared between the two groups.

RESULTS

The rates of major postoperative complications did not significantly differ between the isolation and non-isolation groups (2.5% vs. 4.3%, P = 0.609). The postoperative LTR rates were significantly different between the isolation and non-isolation groups (4.8% vs. 17.5%, P = 0.032). Balloon catheter isolation [odds ratio (OR) = 0.225, 95% confidence interval (CI): 0.085-0.595, P = 0.009] and tumor diameter (OR = 2.808, 95% CI: 1.186-6.647, P = 0.019) were identified as independent factors influencing LTR rate. The cumulative LTP rates at 6 and 12 months after ablation showed no significant differences between the isolation and non-isolation groups (2.6% vs. 7.9%, P = 0.661; 4.9% vs. 9.8%, P = 0.676, respectively). Cox proportional hazards regression analysis showed that tumor diameter was an independent risk factor for cumulative LTP rate (OR = 3.445, 95% CI: 1.406-8.437, P = 0.017).

CONCLUSIONS

Balloon catheter isolation-assisted MWA was safe and effective in the treatment of difficult-site liver cancer. Additionally, tumor diameter significantly influenced LTR and LTP rates after ablation.

Risk Reduction of Intrahepatic Abscess After Locoregional Therapy for Liver Cancer in Patients with Prior Hepatobiliary Intervention

Intrahepatic abscess is an exceedingly rare complication of locoregional therapy for patients with liver cancer. However, in patients who underwent prior hepatobiliary intervention, the incidence of liver abscess increases significantly, causing morbidity and even mortality in such patients. Here, we will review the relative risk of developing a liver abscess after intraarterial and ablative locoregional therapies in patients with liver cancer depending on whether they underwent any kind of prior hepatobiliary procedures that resulted in violation of the Ampulla of Vater. As a result, patients deemed at high risk of developing a liver abscess were treated prophylactically, with the combination of bowel preparation and antibiotics nearly eliminating the occurrence of a liver abscess after locoregional therapy. Therefore, given the significant risk of developing a liver abscess in patients with prior hepatobiliary procedures, management consisting of prophylactic bowel preparation with antibiotic coverage followed by antibiotics post-locoregional therapy is recommended.

Evaluation of parotid and submandibular salivary glands with ultrasonography in diabetic patients

OBJECTIVES

The main symptom of diabetes mellitus (DM) is hyperglycaemia, and patients with DM often have microvascular complications, such as retinopathy, neuropathy, and nephropathy; macrovascular complications, such as coronary heart disease, peripheral arterial disease and cerebrovascular disease; and oral complications, such as xerostomia, hyposalivation and periodontal disease. The main aim of this study was to evaluate the submandibular and parotid glands in type 2 DM patients and healthy individuals and to determine the changes in the salivary glands caused by diabetes.

MATERIALS AND METHODS

In this study, the salivary glands of 100 patients (50 individuals with type 2 DM and 50 healthy individuals) were evaluated by ultrasonography (US). Echogenicity, parenchymal homogeneity, hypoechogenic and hyperechogenic areas, margin characteristics, and vascularity of the glands were analysed. The anteroposterior, superoinferior, and mediolateral lengths and volumes of the submandibular glands were measured.

RESULTS

Statistically significant differences in submandibular gland echogenicity, parotid gland vascularity, and hyperechogenic reflections of the parotid glands were observed between the groups (p < 0.05). In addition, the volume and dimensions of the submandibular glands were significantly greater in the type 2 DM group.

CONCLUSIONS

DM leads to changes in the salivary glands. US, which has many advantages for salivary gland imaging, is a highly effective method for investigating these changes in individuals with diabetes.

CLINICAL RELEVANCE

US, which is well tolerated by patients and does not involve ionizing radiation, can be used for long-term monitoring of the effects of diabetes mellitus on the salivary glands.

Construction of nomogram model based on contrast-enhanced ultrasound parameters to predict the degree of pathological differentiation of hepatocellular carcinoma

Objective

To predict the degree of pathological differentiation of hepatocellular carcinoma (HCC) by quantitative analysis the correlation between the perfusion parameters of contrast-enhanced ultrasound (CEUS) and the pathological grades of HCC using VueBox® software.

Methods

We enrolled 189 patients who underwent CEUS and liver biopsy at our hospital from July 2019 to September 2024 and were pathologically confirmed with primary HCC. The Edmondson-Steiner pathological classification system was used as the gold standard for dividing the patients into the low-grade and high-grade groups. The patients were randomly divided into training set and testing set in a ratio of 7:3, in which the parameters of the training set were analyzed by univariate analysis and then stepwise regression to construct the prediction model, and the diagnostic efficacy of the validation model was evaluated by discrimination, calibration, and clinical applicability.

Results

A total of 189 patients with primary hepatocellular carcinoma were enrolled, including 118 patients in the low-grade group and 71 patients in the high-grade group; they were randomly divided into training set of 128 patients and testing set of 61 patients. The prediction model was constructed by logistic regression in the training set, and the final model included three variables: mTTI, FT, and maximum diameter of a single lesion, resulting in the equation was Y = - 2.360 + 1.674 X 1 + 1.019 X 2 + 0.753 X 3 ( 2 ) + 1.570 X 3 ( 3 ) .The area under the ROC curve (AUC) of the training set was 0.831, with a sensitivity of 82.0% and a specificity of 79.5%; the area under the ROC curve (AUC) of the testing set was 0.811, with a sensitivity of 81.0% and a specificity of 70.0%.

Conclusion

The regression model constructed by combining multiple parameters can effectively improve the diagnostic performance of CEUS in predicting the pathological differentiation grade of HCC, thus providing a clinical basis and empirical support for the use of CEUS as a diagnostic imaging method for this disease.

Microwave ablation for liver metastases from colorectal cancer: A comprehensive review of clinical efficacy and safety

Microwave ablation (MWA) is emerging as a highly effective treatment for colorectal liver metastases (CRLMs). This review explores the advantages of MWA compared to other ablative techniques such as radiofrequency ablation and cryoablation and highlights its clinical efficacy, safety, and technical considerations. MWA offers significant benefits, including higher intratumoral temperatures, larger ablation zones, and reduced susceptibility to the heat-sink effect, which make it particularly suitable for tumors near large blood vessels. This review details the patient selection criteria, procedural approaches, and the use of advanced imaging techniques to improve the precision and effectiveness of MWA. Clinical outcomes indicate that MWA achieves high rates of complete tumor ablation and long-term survival with a favorable safety profile. This review is significant because it provides updated insights into the expanding role of MWA in treating unresectable CRLM and its potential as an alternative to surgical resection for resectable tumors. By summarizing recent studies and clinical trials, this review highlights the comparative effectiveness, safety, and integration with systemic therapies of MWA. In conclusion, MWA is a promising treatment option for CRLM and offers outcomes comparable to or better than those of other ablative techniques. Future research should focus on optimizing technical parameters, integrating MWA with systemic therapies, and conducting large-scale randomized controlled trials to establish standardized treatment protocols. Advancing our understanding of MWA will enhance its application and improve long-term survival and quality of life for patients with CRLM.

Comparative outcomes of ultrasound-guided radiofrequency ablation vs. microwave ablation for patients with T1N0M0 papillary thyroid carcinoma: a retrospective cohort study

OBJECTIVE

To compare the clinical outcomes between radiofrequency ablation (RFA) and microwave ablation (MWA) for the treatment of T1N0M0 papillary thyroid carcinoma (PTC) in a large cohort.

MATERIALS AND METHODS

This retrospective study included 1111 patients with solitary T1N0M0 PTC treated with RFA (n = 894) or MWA (n = 215) by experienced physicians. A propensity score matching was used to compare disease progression, including lymph node metastases (LNM), recurrent tumors and persistent tumors, recurrence-free survival (RFS), volume reduction ratio (VRR), and complications between the RFA and MWA groups. The subgroup outcomes of T1a and T1b tumors treated with RFA and MWA were also compared.

RESULTS

During a mean follow-up period of 41.7 ± 12.6 months, the overall incidence rates of disease progression, LNM, recurrent tumors, and persistent tumors were 2.1%, 0.7%, 1.2%, and 0.2%, respectively. Eight patients (0.7%) experienced transient voice change and recovered within 3 months. After 1:1 matching, there were no significant differences in disease progression (3.3% vs. 3.7%, p = 0.793), LNM (1.4% vs. 1.9%, p = 1.000), recurrent tumor (1.4% vs. 1.9%, p = 1.000), persistent tumors (0.5% vs. 0%, p = 0.317), RFS rates (96.7% vs. 96.3%, p = 0.821), VRR (99.3 ± 3.0% vs. 98.3 ± 8.5%, p = 0.865), tumor disappearance rate (87.9% vs. 81.4%, p = 0.061) and complications (1.4% vs. 1.9%, p = 1.000) between the RFA and MWA groups. For T1a and T1b tumors, clinical outcomes were comparable between RFA and MWA.

CONCLUSIONS

RFA and MWA did not show significant differences in clinical outcomes for T1N0M0 PTC. The choice between RFA and MWA could depend on physician expertise and resources of local center resources. A qualified and experienced physician with extensive knowledge of the modalities is recommended when thermal ablation is performed.

KEY POINTS

Question With radiofrequency ablation (RFA) and microwave ablation (MWA) used worldwide for T1N0M0 papillary thyroid carcinoma (PTC), is one of them superior to the others? Findings There were no significant differences in disease progression, recurrence-free survival, volume reduction ratio, tumor disappearance, or complications between techniques for solitary T1N0M0 papillary thyroid carcinoma. Clinical relevance The choice between RFA and MWA could depend on physician expertise and resources of the local center resources. A qualified and experienced physician with extensive knowledge of the modalities is recommended when thermal ablation is performed.

Multicenter study of thermal ablation versus partial thyroidectomy for paratracheal papillary thyroid microcarcinoma

OBJECTIVE

To compare the clinical outcomes of patients with unifocal paratracheal papillary thyroid microcarcinoma (PTMC) after thermal ablation (TA) vs. partial thyroidectomy (PT).

MATERIALS AND METHODS

This retrospective multicenter study included 436 patients with unifocal, clinical N0 paratracheal PTMC who underwent TA (210 patients) or PT (236 patients) between June 2014 and December 2020. The propensity score matching method was used to mitigate confounding factors between the two groups. Disease progression, progression-free survival (PFS), complications, and treatment variables were compared. Adjusted Cox regression models were utilized to assess the impact of treatment on disease progression.

RESULTS

After matching, a comparable incidence of disease progression (3.3% vs. 2.2%, p = 0.79) and comparable 5-year PFS rates (97.0% vs. 97.4%, p = 0.75) were observed between the TA and PT groups. Adjusted Cox regression models showed no significant correlation between TA and disease progression. TA was associated with shorter hospitalization (0 vs. 6.0 days), less estimated blood loss (0 vs. 15.0 mL), shorter incision length (0.3 vs. 6.0 cm), and lower costs ($1748.3 vs. $2898.0) compared with PT (all p < 0.001). The complication rate was 1.1% after TA and 3.3% after PT (p = 0.28), with permanent complications were exclusively observed in the PT group.

CONCLUSION

The mid-term incidence of disease progression and PFS rates were similar between TA and PT in patients with unifocal paratracheal PTMC. TA might represent a promising alternative treatment to PT for eligible patients with paratracheal PTMC.

KEY POINTS

Question Is thermal ablation a viable alternative treatment to partial thyroidectomy for treating paratracheal papillary thyroid microcarcinoma? Findings Comparable incidence of disease progression and 5-year progression-free survival rates were observed between thermal ablation and partial thyroidectomy. Clinical relevance Thermal ablation, as a minimally invasive procedure, provides a promising alternative to partial thyroidectomy, with comparable clinical outcomes for patients with paratracheal papillary thyroid microcarcinoma.

Application value of different imaging methods in the early diagnosis of small hepatocellular carcinoma: a network meta-analysis

Objective

To determine the diagnostic value of ultrasound, multi-phase enhanced computed tomography, and magnetic resonance imaging of small hepatocellular carcinoma.

Methods

Experimental studies on diagnosing small hepatocellular carcinoma in four databases: PubMed, Cochrane Library, Web of Science, and Embase, were comprehensively searched from October 2007 to October 2024. Relevant diagnostic accuracy data were extracted and a Bayesian model that combined direct and indirect evidence was used for analysis.

Results

16 original studies were included and data from 2,447 patients were collated to assess the diagnostic value of 10 different methods. The methodological quality of the included studies was good and there was no obvious publication bias. The pooled DOR of all diagnostic methods was 19.61, which was statistically significant (I2 = 76.0%, P < 0.01, 95% CI:13.30 - 28.92). Normal US + CEUS + ultrasonic elastic imaging had the highest specificity (92.9), accuracy (93.6), and positive predictive value (94.4). Unenhanced MRI + Contrast-enhanced MRI had the highest sensitivity (96.6) and negative predictive value (96.6), but specificity (12.5) and positive predictive value (34.4) were extremely poor. Contrast-enhanced MRI had the highest diagnostic value in individual imaging methods (sensitivity: 66, specificity: 55.5, accuracy: 67.9, positive predictive value: 64.4, negative predictive value: 66.5). There was significant inconsistency and high heterogeneity in this study.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024507883.

A Novel Ultrasound Thermometry Method Based on Thermal Strain and Short and Constant Acoustic Bursts: Preliminary Study in Phantoms

In the field of ultrasound therapy, the estimation of temperature to monitor treatments is becoming essential. We hypothesize that it is possible to measure temperature directly using a constant acoustic power burst. Under the assumption that the acoustic attenuation does not change significantly with temperature, the thermal strain induced by such bursts presents a linear relation with temperature. A mathematical demonstration is given in the introduction. Then, simulations of ultrasound waves in a canine liver model were conducted at different temperatures (from 20 °C to 90 °C). Finally, experimental measurements on phantom samples were performed over the same temperature range. The simulation and experimental results both showed a linear relation between thermal strain and temperature. This relation may suggest the foundation of a new ultrasound-based thermometry method. The potential and limitations of the method are discussed.

How Can We Improve the Survival of Patients with Colorectal Liver Metastases Using Thermal Ablation?

Thermal ablation has been widely used for patients with small colorectal liver metastases (CRLMs), even for resectable cases; however, solid evidence has been scarce. (1) Thermal ablation versus liver resection. Some propensity-score matching studies using patients with balanced baseline characteristics have confirmed less invasiveness and the comparable survival benefits of thermal ablation to liver resection. A more recent pivotal randomized controlled trial comparing thermal ablation and liver resection was presented during the American Society of Clinical Oncology 2024 meeting. Diameter ≤ 3 cm, ten or fewer resectable and ablatable CRLMs were assigned to thermal ablation or liver resection. No differences were observed in the overall survival and local and distant progression-free survival with less morbidity. (2) Combination of thermal ablation and liver resection. Four matching studies demonstrated comparable data between the combination and liver resection alone groups in the long-term survival and recurrence rates without increasing the postoperative complication rates. The selection of the two approaches depends primarily on the number, size, and location of the CRLMs. (3) Chemotherapy in combination with thermal ablation. A propensity-score matching study comparing thermal ablation ± neoadjuvant chemotherapy was conducted. The addition of neoadjuvant chemotherapy was an independent predictive factor for good progression-free survival without increasing morbidity. Two randomized controlled trials demonstrated that additional thermal ablation to systemic chemotherapy can improve the overall survival for initially unresectable CRLMs. (4) Conclusions. Thermal ablation can provide survival benefits for patients with CRLMs in various situations, keeping adequate indications.

Fiber Bragg Grating Thermometry and Post-Treatment Ablation Size Analysis of Radiofrequency Thermal Ablation on Ex Vivo Liver, Kidney and Lung

Radiofrequency ablation (RFA) is a minimally invasive procedure that utilizes localized heat to treat tumors by inducing localized tissue thermal damage. The present study aimed to evaluate the temperature evolution and spatial distribution, ablation size, and reproducibility of ablation zones in ex vivo liver, kidney, and lung using a commercial device, i.e., Dophi™ R150E RFA system (Surgnova, Beijing, China), and to compare the results with the manufacturer's specifications. Optical fibers embedding arrays of fiber Bragg grating (FBG) sensors, characterized by 0.1 °C accuracy and 1.2 mm spatial resolution, were employed for thermometry during the procedures. Experiments were conducted for all the organs in two different configurations: single-electrode (200 W for 12 min) and double-electrode (200 W for 9 min). Results demonstrated consistent and reproducible ablation zones across all organ types, with variations in temperature distribution and ablation size influenced by tissue characteristics and RFA settings. Higher temperatures were achieved in the liver; conversely, the lung exhibited the smallest ablation zone and the lowest maximum temperatures. The study found that using two electrodes for 9 min produced larger, more rounded ablation areas compared to a single electrode for 12 min. Our findings support the efficacy of the RFA system and highlight the need for tailored RFA parameters based on organ type and tumor properties. This research provides insights into the characterization of RFA systems for optimizing RFA techniques and underscores the importance of accurate thermometry and precise procedural planning to enhance clinical outcomes.

Principles of Doppler Ultrasonography and Basic Applications for the Clinician

Doppler ultrasonography has evolved into a cornerstone of ultrasound imaging. In this article, we delve into the fundamental principles of Doppler ultrasonography, introduce color and spectral Doppler analysis, and highlight common applications relevant to point-of-care (POCUS) practitioners. From enhancing the safety of bedside procedures to estimating cardiac output, to exploring findings of venous congestion, we review the key advantages, disadvantages, and challenges of using Doppler in POCUS.

Role of volumetric tumor enhancement on CT in predicting overall survival in patients with unresectable pancreatic ductal adenocarcinoma

PURPOSE

To assess the utility of volumetric tumor enhancement on CT to predict tumor treatment response and the overall survival (OS) of patients with PDAC undergoing FOLFIRINOX-based systemic chemotherapy. Additionally, we aim to explore the performance of a novel model that incorporates relevant volumetric CT-derived parameters to the established RECIST 1.1 in predicting both treatment response and OS.

MATERIAL AND METHODS

In this retrospective single-institution study, 127 patients with PDAC who received FOLFIRINOX neoadjuvant chemotherapy between December 2012 and November 2021 were included. Manual volumetric segmentation of the single largest tumor was performed on portal venous phase images. Total and enhancing tumor volumes were calculated. Response by RECIST 1.1 was compared to response by tumor volume and enhancing tumor volume on follow-up CT.

RESULTS

There was no association between overall survival and RECIST 1.1 (p-value = 0.284), volumetric RECIST (p-value = 0.402), and other volumetric CT variables, except for a percentage reduction in enhancing tumor volume (p-value = 0.043). Using univariate survival analysis for categorical thresholds defined by CART, the percentage change in enhancing tumor volume was associated with OS (p-value = 0.018). There was also a significant association between baseline enhancing tumor volume and OS (p-value <0.0001). Using these two categories, we defined a multivariable model associated with OS (p-value <0.0001).

CONCLUSION

Percentage reduction in enhancing tumor volume was related to OS in non-surgical PDAC patients treated with FOLFIRINOX chemotherapy and could potentially be incorporated into patient survival prediction models.

Smart goggles augmented reality CT-US fusion compared to conventional fusion navigation for percutaneous needle insertion

PURPOSE

Targeting accuracy determines outcomes for percutaneous needle interventions. Augmented reality (AR) in IR may improve procedural guidance and facilitate access to complex locations. This study aimed to evaluate percutaneous needle placement accuracy using a goggle-based AR system compared to an ultrasound (US)-based fusion navigation system.

METHODS

Six interventional radiologists performed 24 independent needle placements in an anthropomorphic phantom (CIRS 057A) in four needle guidance cohorts (n = 6 each): (1) US-based fusion, (2) goggle-based AR with stereoscopically projected anatomy (AR-overlay), (3) goggle AR without the projection (AR-plain), and (4) CT-guided freehand. US-based fusion included US/CT registration with electromagnetic (EM) needle, transducer, and patient tracking. For AR-overlay, US, EM-tracked needle, stereoscopic anatomical structures and targets were superimposed over the phantom. Needle placement accuracy (distance from needle tip to target center), placement time (from skin puncture to final position), and procedure time (time to completion) were measured.

RESULTS

Mean needle placement accuracy using US-based fusion, AR-overlay, AR-plain, and freehand was 4.5 ± 1.7 mm, 7.0 ± 4.7 mm, 4.7 ± 1.7 mm, and 9.2 ± 5.8 mm, respectively. AR-plain demonstrated comparable accuracy to US-based fusion (p = 0.7) and AR-overlay (p = 0.06). Excluding two outliers, AR-overlay accuracy became 5.9 ± 2.6 mm. US-based fusion had the highest mean placement time (44.3 ± 27.7 s) compared to all navigation cohorts (p < 0.001). Longest procedure times were recorded with AR-overlay (34 ± 10.2 min) compared to AR-plain (22.7 ± 8.6 min, p = 0.09), US-based fusion (19.5 ± 5.6 min, p = 0.02), and freehand (14.8 ± 1.6 min, p = 0.002).

CONCLUSION

Goggle-based AR showed no difference in needle placement accuracy compared to the commercially available US-based fusion navigation platform. Differences in accuracy and procedure times were apparent with different display modes (with/without stereoscopic projections). The AR-based projection of the US and needle trajectory over the body may be a helpful tool to enhance visuospatial orientation. Thus, this study refines the potential role of AR for needle placements, which may serve as a catalyst for informed implementation of AR techniques in IR.

Decision-Making for Ablation of Colorectal Liver Oligometastases Patients: A 10-Year Retrospective Study of Survival Outcomes Based on Right-Versus Left-Sided Primary Tumor Location

ObjectiveTo develop a prognostic model for optimizing management of colorectal liver oligometastases (CLOM) patients with different primary tumor locations who underwent thermal ablation (TA).Materials and MethodsThe reporting of this retrospective study conforms to STROBE guidelines. A total of 525 CLOM patients who underwent TA from 3 hospitals between 2011 and 2021 were enrolled. Firstly, intra and extrahepatic disease-free survival (DFS) and overall survival (OS) for CLOM patients with different primary tumor locations were analyzed. Then, cox regression models were used to identify independent factors predicting OS. Finally, a prognostic score was developed to identify CLOM patients benefiting from TA. All patient details were de-identified.ResultsA total of 423 eligible patients were identified, with 762 CLOM (121 male, median age 59 years) and a median follow-up of 45.8 (IQR, 7.3-114.8) months. Independent predictors of OS were identified, including multiple liver metastases (P = .0085), right-sided colon cancer (P = .0210), tumor size ≥2 cm (P = .0273), and lymph node metastasis of primary colorectal cancer (P = .0302), termed as the "MRSL" score. On the basis of the best separation of MRSL score, patients were divided into high-risk (cutoff value ≥8) and low-risk groups (cutoff value <8). Further stratified analysis indicated that right-sided CLOM patients had shorter OS than left-sided patients in the high-risk group (54.9 vs 92.5 months, P = .0156). However, no significant difference in OS was observed between right-sided and left-sided CLOM patients in the low-risk group (97.7 vs 102.2 months, P = .28).ConclusionThe MRSL score-based model helps in selecting potential right-sided CLOM patients who benefit from TA.

Achieving and Maintaining Excellence: A Roadmap for Ultrasound Practices

This article outlines a roadmap to achieving and maintaining excellence in an ultrasound (US) practice. We present constructive advice on how US practices can achieve and maintain quality, patient and referring physician satisfaction, and efficiency in the setting of rising examination volumes. Accreditation, sonographer and resident/fellow physician training, advanced practice sonographers, and Picture Archiving and Communication System/Artificial Intelligence in US are discussed. Advice for how to begin offering new US examinations, begin a practice at new US locations, improve quality assurance, and enhance marketing are covered.

Global registration of kidneys in 3D ultrasound and CT images

PURPOSE

Automatic registration between abdominal ultrasound (US) and computed tomography (CT) images is needed to enhance interventional guidance of renal procedures, but it remains an open research challenge. We propose a novel method that doesn't require an initial registration estimate (a global method) and also handles registration ambiguity caused by the organ's natural symmetry. Combined with a registration refinement algorithm, this method achieves robust and accurate kidney registration while avoiding manual initialization.

METHODS

We propose solving global registration in a three-step approach: (1) Automatic anatomical landmark localization, where 2 deep neural networks (DNNs) localize a set of landmarks in each modality. (2) Registration hypothesis generation, where potential registrations are computed from the landmarks with a deterministic variant of RANSAC. Due to the Kidney's strong bilateral symmetry, there are usually 2 compatible solutions. Finally, in Step (3), the correct solution is determined automatically, using a DNN classifier that resolves the geometric ambiguity. The registration may then be iteratively improved with a registration refinement method. Results are presented with state-of-the-art surface-based refinement-Bayesian coherent point drift (BCPD).

RESULTS

This automatic global registration approach gives better results than various competitive state-of-the-art methods, which, additionally, require organ segmentation. The results obtained on 59 pairs of 3D US/CT kidney images show that the proposed method, combined with BCPD refinement, achieves a target registration error (TRE) of an internal kidney landmark (the renal pelvis) of 5.78 mm and an average nearest neighbor surface distance (nndist) of 2.42 mm.

CONCLUSION

This work presents the first approach for automatic kidney registration in US and CT images, which doesn't require an initial manual registration estimate to be known a priori. The results show a fully automatic registration approach with performances comparable to manual methods is feasible.

Microwave vs radiofrequency ablation for small renal masses: perioperative and oncological outcomes

OBJECTIVE

To conduct a comprehensive comparison of microwave ablation (MWA) vs radiofrequency ablation (RFA) outcomes in the treatment of small renal masses (SRMs), specifically: TRIFECTA ([i] complete ablation, [ii] absence of Clavien-Dindo Grade ≥III complications, and [iii] absence of ≥30% decrease in estimated glomerular filtration rate) achievement, operative time (OT), and local recurrence rate (LRR).

PATIENTS AND METHODS

We retrospectively analysed 531 patients with SRMs (clinical T1a-b) treated with MWA or RFA at a single centre (2008-2022). First, multivariable logistic regression models were used for testing TRIFECTA achievement. Second, multivariable Poisson regression models were used to evaluate variables associated with longer OT. Finally, Kaplan-Meier plots depicted LRR over time. All analyses were repeated after 1:1 propensity score matching (PSM).

RESULTS

Of 531 patients with SRMs, 373/531 (70.2%) underwent MWA and 158/531 (29.8%) RFA. MWA demonstrated superior TRIFECTA achievement (314/373 [84.2%]) compared to RFA (114/158 [72.2%], P = 0.001). These differences were driven by higher rates of complete ablation in MWA- vs RFA-treated patients (348/373 [93.3%] vs 137/158 [86.7%], P < 0.001). In multivariable logistic regression models, MWA was associated with higher TRIFECTA achievement, compared to RFA, before (odds ratio [OR] 1.92, P = 0.008) and after PSM (OR 1.99, P = 0.023). Finally, the median OT was shorter for MWA vs RFA (105 vs 115 min; P = 0.002). At Poisson regression analyses, MWA predicted shorter OT before (incidence rate ratio [IRR] 0.86, P < 0.001) and after PSM (IRR 0.85, P < 0.001). Local recurrence occurred in 17/373 (4.6%) MWA-treated patients and 21/158 (13.3%) RFA-treated patients (P = 0.29) after a median (interquartile range) follow-up of 24 (8-46) months. There were no differences in the LRR in Kaplan-Meier plots before (P = 0.29) and after PSM (P = 0.42).

CONCLUSION

Microwave ablation provides higher TRIFECTA achievement, and shorter OT than RFA. No significant differences were found regarding the LRR.

Thyroid Radiofrequency Ablation-Thermal Effects on Recurrent Laryngeal Nerve Using Continuous Intraoperative Neuromonitoring Animal Model

OBJECTIVE

When performing radiofrequency ablation for thyroid nodules, it is essential to avoid thermal injury to the recurrent laryngeal nerve. This porcine animal model study used continuous intraoperative neuromonitoring to investigate the thermal safety parameters of thyroid radiofrequency ablation.

STUDY DESIGN

Porcine animal study.

SETTING

University animal laboratory.

METHODS

Twelve piglets were tested at different radiofrequency power levels, and the real-time electromyography signal changes were recorded under continuous intraoperative neuromonitoring. The spread heat study (8 piglets) included spontaneous recovery tests and cold water irrigation tests to investigate the safety distance from the recurrent laryngeal nerve to the active tip during 5-second activation with standard stimulation patterns. The residual heat study (4 piglets) investigated the safety cooling durations by touching the recurrent laryngeal nerve with the tip after a 5-second activation.

RESULTS

In the spread heat study, substantial signal attenuation events were observed at an spread heat distance of 2, 3, 5, and 5 mm when the power was set as 10, 20, 30, and 50 W, respectively. No signal recovery could be observed in 20 minutes with or without cold water irrigation in the injured recurrent laryngeal nerve area. The residual heat study shows the residual thermal effect of the tip is minimal, and no substantial signal attenuation event was observed at all experiments.

CONCLUSIONS

This innovative study established the thermal safety parameters for radiofrequency ablation in a porcine model at various power levels, which can potentially assist operators in delineating a precise ablation field and providing effective thyroid ablation treatment safely.

Augmented Reality for Surgical Navigation: A Review of Advanced Needle Guidance Systems for Percutaneous Tumor Ablation

Percutaneous tumor ablation has become a widely accepted and used treatment option for both soft and hard tissue malignancies. The current standard-of-care techniques for performing these minimally invasive procedures require providers to navigate a needle to their intended target using two-dimensional (2D) US or CT to obtain complete local response. These traditional image-guidance systems require operators to mentally transpose what is visualized on a 2D screen into the inherent three-dimensional (3D) context of human anatomy. Advanced navigation systems designed specifically for percutaneous needle-based procedures often fuse multiple imaging modalities to provide greater awareness and planned needle trajectories for the avoidance of critical structures. However, even many of these advanced systems still require mental transposition of anatomy from a 2D screen to human anatomy. Augmented reality (AR)-based systems have the potential to provide a 3D view of the patient's anatomy, eliminating the need for mental transposition by the operator. The purpose of this article is to review commercially available advanced percutaneous surgical navigation platforms and discuss the current state of AR-based navigation systems, including their potential benefits, challenges for adoption, and future developments. Keywords: Computer Applications-Virtual Imaging, Technology Assessment, Augmented Reality, Surgical Navigation, Percutaneous Ablation, Interventional Radiology ©RSNA, 2025.

Acoustic radiation force impulse (push pulse)-induced lung hemorrhage: investigating the effect of ultrasound contrast agent in rabbits

PURPOSE

Acoustic radiation force impulse (ARFI) elastography and contrast-enhanced ultrasonography (CEUS) are emerging techniques that are becoming common in ultrasound examinations. We previously reported that ARFI (push pulse) induced lung hemorrhage in rabbits, indicating that greater risks are associated with ARFI than with conventional ultrasound. In this study, we assessed the risk of lung hemorrhage under a combination of ARFI elastography and CEUS, considering potential exacerbation of ARFI-induced lung hemorrhage as a result of the ultrasound contrast agent (UCA) used in CEUS.

METHODS

Twenty-three rabbits were divided into non-UCA and UCA groups. ARFI exposure parameters were set at six mechanical index (MI) levels (0.29, 0.45, 0.60, 0.88, 1.0, 1.39) in non-UCA groups and five MI levels (0.29, 0.66, 0.88, 0.97, 1.25) in UCA groups. Lung exposure was performed bilaterally through the intercostal space in each rabbit. Lung damage was assessed through macroscopic and microscopic observation post euthanasia.

RESULTS

Lung hemorrhage was detected at MI0.3 levels of 0.88 or higher. Logistic regression analyses showed that MI0.3 was a statistically significant factor for occurrence of lung hemorrhage in both non-UCA and UCA groups, and the MI0.3 threshold (ED05) for inducing lung hemorrhage was 0.68 and 0.71, respectively. However, multivariate logistic regression and linear regression analyses across all samples indicated that UCA did not significantly affect the occurrence or area of lung hemorrhage.

CONCLUSION

This study demonstrates that UCA does not significantly worsen ARFI-induced lung hemorrhage in terms of occurrence or severity. However, risks and benefits of ARFI elastography on the lung should be considered, irrespective of UCA administration.

Outcomes of First-Line Microwave Ablation of Treatment-Naive Epidermal Growth Factor Receptor-Mutated Advanced Lung Adenocarcinoma Treated with Tyrosine Kinase Inhibitors

PURPOSE

To investigate the outcomes of first-line image-guided microwave ablation (MWA) plus tyrosine kinase inhibitors (TKIs) in untreated epidermal growth factor receptor (EGFR)-mutant advanced lung adenocarcinoma (LUAD) and to compare with TKIs alone.

MATERIALS AND METHODS

This retrospective cohort study included patients between December 2015 and December 2021 and was divided into 2 groups (Group A: first-line MWA+TKIs; Group B: TKIs alone). Progression-free survival (PFS) was the primary end point, whereas overall survival (OS) was the secondary end point and were compared via the Kaplan-Meier methods. Univariate and multivariate analyses were used to investigate the predictors of PFS and OS. Propensity score matching (1:1 ratio) was applied between Group B and the subgroup of complete ablation in Group A.

RESULTS

A total of 117 patients were included (Group A: n = 43; Group B: n = 74). In a mean follow-up of 47.0 months (SD ± 19.4), Group A had significantly longer median PFS (19.0 vs 10.0 months; P < .001) and OS (41.0 vs 25.0 months; P = .044) than Group B. Predictors of PFS included first-line MWA (P < .001) and tumor stage (P = .020), while that of OS included first-line MWA (P = 0.039), tumor stage (P = 0.014), and usage of third-generation TKIs (P = 0.001). There were 23 pairs of patients obtained after propensity score matching (Group A1: complete ablation+TKIs; Group B1: TKIs alone). Group A1 had significantly longer median PFS (24.0 vs 10.0 months; P < .001) and OS (48.0 vs 24.0 months; P = .012) than Group B1.

CONCLUSIONS

First-line MWA significantly improved the outcomes of patients with untreated EGFR-mutant advanced LUAD treated with TKIs. Complete ablation predicted a better prognosis.

Unveiling the potential of ultrasound in brain imaging: Innovations, challenges, and prospects

Within medical imaging, ultrasound serves as a crucial tool, particularly in the realms of brain imaging and disease diagnosis. It offers superior safety, speed, and wider applicability compared to Magnetic Resonance Imaging (MRI) and X-ray Computed Tomography (CT). Nonetheless, conventional transcranial ultrasound applications in adult brain imaging face challenges stemming from the significant acoustic impedance contrast between the skull bone and soft tissues. Recent strides in ultrasound technology encompass a spectrum of advancements spanning tissue structural imaging, blood flow imaging, functional imaging, and image enhancement techniques. Structural imaging methods include traditional transcranial ultrasound techniques and ultrasound elastography. Transcranial ultrasound assesses the structure and function of the skull and brain, while ultrasound elastography evaluates the elasticity of brain tissue. Blood flow imaging includes traditional transcranial Doppler (TCD), ultrafast Doppler (UfD), contrast-enhanced ultrasound (CEUS), and ultrasound localization microscopy (ULM), which can be used to evaluate the velocity, direction, and perfusion of cerebral blood flow. Functional ultrasound imaging (fUS) detects changes in cerebral blood flow to create images of brain activity. Image enhancement techniques include full waveform inversion (FWI) and phase aberration correction techniques, focusing on more accurate localization and analysis of brain structures, achieving more precise and reliable brain imaging results. These methods have been extensively studied in clinical animal models, neonates, and adults, showing significant potential in brain tissue structural imaging, cerebral hemodynamics monitoring, and brain disease diagnosis. They represent current hotspots and focal points of ultrasound medical research. This review provides a comprehensive summary of recent developments in brain imaging technologies and methods, discussing their advantages, limitations, and future trends, offering insights into their prospects.

Optimal treatment strategies for borderline resectable liver metastases from colorectal cancer

BACKGROUND

Traditionally, colorectal liver metastases (CRLMs) are divided into "initially resectable" and "initially unresectable." The terminology "borderline resectable" continues to be elusive without any common consensus or definition. This narrative review aims to decode the conundrum of "borderline resectable CRLM (BR-CRLM)" and to discuss optimal treatment strategies.

METHODS

A comprehensive review was performed using Medline/PubMed and Web of Science databases with a search period ending on January 1, 2024. Using PubMed, the terms "CRLM," "BR-CRLM," and "management of BR-CRLM" were searched.

RESULTS

The 2016 European Society for Medical Oncology guidelines defined the term "resectability" in CRLM using the "technical (surgical) criteria" and the "oncologically criteria." These 2 criteria form the basis of defining BR-CRLM. Thus, BR-CRLM can be either technically easy but with unfavorable oncologically criteria or technically difficult with favorable oncologically criteria. Although defining BR-CRLM by incorporating both these criteria seems to be the most logical way forward, there is currently a lot of heterogeneity in the literature. It is generally agreed upon that some form of chemotherapy needs to be administered in BR-CRLM before embarking on surgery. Conversion chemotherapy is used in patients with BR-CRLM in which there is a possibility of resection after effective downsizing. Along with improved effective chemotherapy, great strides have been made in pushing the limits of surgery to achieve resectability in this subset of patients.

CONCLUSION

Advanced surgical techniques and locoregional liver-directed therapies coupled with perioperative chemotherapy with or without targeted therapy have made long-term survival benefit, a reality in patients with BR-CRLM. Thus, the time has come to recognize "BR-CRLM" as a distinct entity.

Radiofrequency Ablation for Recurrent Thyroid Cancers: 2025 Korean Society of Thyroid Radiology Guideline

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Estimating in vivo power deposition density in thermotherapies based on ultrasound thermal strain imaging

In thermal therapies, accurate estimation of in-tissue power deposition density (PDD) is essential for predicting temperature distributions over time or regularizing temperature imaging. Based on our previous work on ultrasound thermometry, namely, multi-thread thermal strain imaging (MT-TSI), this work develops an in vivo PDD estimation method. Specifically, by combining the TSI model infinitesimal echo strain filter with the bio-heat transfer theory (the Pennes equation), a finite-difference time-domain model is established to allow online extraction of the PDD. An alternating-direction implicit method is adopted to ensure numerical stability and computational efficiency in implementing the model. Based on simulations, the accuracy and effectiveness of the model are examined by comparing a preset PDD distribution with the estimated one. Then, TSI results are obtained from ultrasound data acquired in in vivo experiments; with the PDD estimated from that, TSI distributions are then "predicted" using a validated numerical procedure. The two TSI results are compared to verify the self-consistency of the proposed method. A simplified and more efficient protocol for obtaining an "equivalent spherical PDD" is also discussed.

Long-term clinical outcomes of thermal ablation for benign thyroid nodules and unresolved issues: a comprehensive systematic review

Thermal ablation is widely accepted as an effective and safe method for treating benign thyroid nodules. Many studies reporting short-term results have consistently demonstrated the efficacy and safety of thermal ablation. However, as the clinical application of thermal ablation grows and follow-up periods extend, long-term clinical outcomes of thermal ablation have revealed several issues, including regrowth and diagnosis of malignancy in ablated lesions. In this systematic review, we analyze the long-term clinical outcomes of thyroid thermal ablation, focusing on regrowth, delayed surgery, and the potential for malignancy after thermal ablation and propose solutions to address these unresolved issues and enhance the management of benign thyroid nodules through thermal ablation.

Microwave ablation for colorectal liver metastases with ultrasound fusion imaging assistance: a stratified analysis study based on tumor size and location

PURPOSE

To investigate the efficacy of ultrasound fusion imaging-assisted microwave ablation (MWA) for patients with colorectal liver metastases (CRLM) based on stratified analysis of tumor size and location.

METHODS

Patients with CRLM who underwent ultrasound fusion imaging-assisted MWA in our hospital between February 2020 and February 2023 were enrolled into this retrospective study. Ultrasound fusion imaging was used for detection, guidance, monitoring and immediate evaluation throughout the MWA procedures. Technical success, technique efficacy, local tumor progression (LTP), intrahepatic progression and overall survival (OS) were recorded and analyzed. The subgroup analysis of intrahepatic progression of MWA for CRLM was performed according to tumor size and location.

RESULTS

A total of 51 patients with 122 nodules were enrolled. Both technical success and technique efficacy were acquired in all nodules. In a median follow-up period of 19 months, 2.5% of the nodules (3/122) were observed LTP. The 1-year and 2-year cumulative intrahepatic progression rates were 38.7% and 52.1% respectively. Patients were divided into subgroups according to tumor size (≥ 30 mm, n = 13; < 30 mm, n = 38) and tumor location (perivascular, n = 20; non-perivascular, n = 31 and subcapsular, n = 36; non-subcapsular, n = 15). The cumulative intrahepatic progression rates were similar between the subgroups regarding tumor size and perivascular location, while significantly higher in the subcapsular group than in the non-subcapsular group (p = 0.021).

CONCLUSION

Ultrasound fusion imaging-assisted MWA exhibited satisfactory local efficacy for CRLM, especially for non-subcapsular tumors.

Evaluation of Local Tumor Outcomes Following Microwave Ablation of Colorectal Liver Metastases Using CT Imaging: A Comparison of Visual versus Quantitative Methods

Purpose To compare visual versus quantitative ablation confirmation for identifying local tumor progression and residual tumor following microwave ablation (MWA) of colorectal liver metastases (CRLM). Materials and Methods This retrospective study included patients undergoing MWA of CRLM from October 2014 to February 2018. Two independent readers visually assessed pre- and postprocedure images and semiquantitatively scored for incomplete ablation, using a six-point Likert scale, and extracted quantitative imaging metrics of minimal ablative margin (MAM) and percentage of tumor outside of the ablation zone, using both rigid and deformable registration. Diagnostic accuracy and intra- and interobserver agreement were assessed. Results The study included 60 patients (median age, 71 years [IQR, 60-74.5 years]; 38 male) with 97 tumors with a median diameter of 1.3 cm (IQR, 1.0-1.8 cm). Median follow-up time was 749 days (IQR, 330-1519 days). Median time to complete rigid and deformable workflows was 3.0 minutes (IQR, 3.0-3.2 minutes) and 14.0 minutes (IQR,13.9-14.4 minutes), respectively. MAM with deformable registration had the highest intra- and interobserver agreement, with Gwet AC1 of 0.92 and 0.67, respectively, significantly higher than interobserver agreement of visual assessment (Gwet AC1, 0.18; P < .0001). Overall, quantitative methods using MAM had generally higher sensitivity, of up to 95.6%, than visual methods (67.3%, P < .001), at a cost of lower specificity (40% vs 71.1%, P < .001), using deformable image registration. Conclusion Quantitative ablation margin metrics provide more reliable assessment of outcomes than visual comparison using pre- and postprocedure diagnostic images following MWA of CRLM. Keywords: Interventional-Body, Liver, Neoplasms, Ablation Techniques Supplemental material is available for this article. Published under a CC BY 4.0 license.

Multi-stage automatic and rapid ablation and needle trajectory planning method for CT-guided percutaneous liver tumor ablation

BACKGROUND

Computer-assisted planning methods have increasingly contributed to preoperative ablation planning; however, these methods cannot automatically obtain the final optimal solution within a short time and are rarely validated in practice, greatly limiting their clinical applicability.

PURPOSE

We aimed to propose a full-automatic multi-stage ablation and needle trajectory planning method for CT-guided percutaneous liver ablation to attain the final optimal plans under multiple clinical constraints rapidly.

METHODS

Our proposed method integrates the ablation zone planning fulfilling complete tumor coverage and critical structure avoidance while reaching a trade-off between ablation number and healthy tissue damage, and needle trajectory planning under multiple clinical constraints. Our needle trajectory planning determines feasible skin entry regions based on hard constraints, where the multi-objective optimization (MOO) considering soft constraints is performed using the Pareto Optimality and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methods for the final optimal solution. The performance of our proposed method was evaluated on 30 tumors of various characteristics from 23 patients and clinically validated in five clinical cases.

RESULTS

Our proposed method achieved 99.8% treatment zone coverage and 40.5% ablation efficiency without involving critical structures, and completely satisfied multiple clinical constraints in all needle trajectory planning results. The average planning time was 23.6 s for tumors of different sizes. All the plans were considered clinically acceptable by the doctors' evaluation. Our method achieved complete tumor coverage without complications in clinical case validation.

CONCLUSION

Our proposed planning method can generate a final optimal plan satisfying multiple clinical constraints within a short time, potentially facilitating preoperative planning for hepatic tumor ablation.

Imaging Classification of Exophytic HCC and Our Experience with Microwave Ablation of Type 2 Lesions

Purpose  The purpose of this article is to classify hepatocellular carcinoma (HCC) based on imaging and to evaluate the role of ultrasound-guided microwave ablation (MWA) in the management of type 2 exophytic HCC. Materials and Methods  A retrospective study was performed at our institution after approval by the Institutional Review Board. The study was undertaken from January 2017 to May 2022. Based on the location, HCC was classified and categorized on cross-sectional imaging into four types. All MWA procedures were performed using ultrasound guidance. Patients were followed up every 3 months with cross-sectional imaging. Results  During the study period, 225 lesions were reviewed. MWA was performed in 13 type 2 exophytic HCC patients. Segment 3 (38%) was the most common site when categorized as per Couinaud classification and segment 6 was the next common site. Technical success of complete ablation, evaluated by postprocedure contrast-enhanced computed tomography scan, was 100%. The median follow-up period was 24 months (range: 9-24 months). One patient presented with a residual lesion on the first follow-up at 30 days. Two other patients followed up to 9 months were free of HCC. Ten patients followed up at 1 year showed no recurrence, while 7 of them were followed up for 24 months, and 1 of whom showed multicentric recurrence which was treated by selective intra-arterial radiation therapy. Conclusion  A classification system for exophytic lesions can allow for better patient selection, planning, and reporting of ablative outcomes. MWA has performed well when ablating these technically challenging lesions with a certain degree of planning.

Early second radiofrequency ablation treatment gave rise to significantly greater nodule shrinkage at 12 months than single-session treatment for large-volume benign thyroid nodules

INTRODUCTION

Radiofrequency ablation (RFA) is an effective nonsurgical treatment for symptomatic benign thyroid nodules. Large-volume nodules (≥20-mL) often require 2 or more radiofrequency ablation sessions to achieve desirable shrinkage but the optimal interval between sessions remains unknown. We hypothesized that early (within 6 months) retreatment could improve nodule shrinkage. This study compared the 12-month volume reduction rate (VRR) and complications between single-session radiofrequency ablation and 2-session radiofrequency ablation within 6 months for large benign thyroid nodules.

METHODS

Consecutive patients with cytologically proven benign thyroid nodules ≥20 mL undergoing radiofrequency ablation were prospectively assigned to undergo either single-session (group 1) or 2-session radiofrequency ablation within 6 months (group 2). All were followed up for at least 12 months after the initial radiofrequency ablation. Volume reduction rate was calculated as (baseline - current volume)/baseline volume × 100%. Complications were documented.

RESULTS

Out of 67 nodules ≥20 mL that underwent radiofrequency ablation, 43 nodules (group 1: n = 23, group 2: n = 20) from 42 patients were analyzed. Both groups had comparable baseline nodule volumes (33.2 ± 14.9 mL vs 34.3 ± 12.5 mL) and clinical parameters (P > .05). The 6-month volume reduction rate was comparable (65.7 ± 13.2% vs 68.6 ± 13.3%, P = .264) but the 12-month volume reduction rate was significantly greater in group 2 (65.9 ± 17.1% vs 75.6 ± 11.5%, P = .019). Group 2 nodules continued to shrink from 6 to 12 months (P = .012), whereas group 1 nodules did not (P = .503). Two-session radiofrequency ablation within 6 months was the only significant factor associated with a 12-month volume reduction rate of ≥75% (odds ratio 4.375, 95% confidence interval 1.210-15.812, P = .024). No vocal cord paresis or hematoma requiring reoperation occurred.

CONCLUSION

Early retreatment with 2-session radiofrequency ablation within 6 months was safe and led to significantly greater nodule shrinkage at 12 months than single-session radiofrequency ablation.

Cone Beam computed tomography (CBCT) applications in image-guided minimally invasive procedures

Cone-Beam computed tomography (CBCT) obtains three-dimensional images using a two-dimensional detector. The use of CBCT in treatment planning and evaluation increases the safety and efficacy of minimally invasive procedures. This article reviews the technical considerations, main clinical applications, and future directions of CBCT in vascular and interventional radiology and interventional neuroradiology.

Diagnosing and management of thyroid nodules and goiter - current perspectives

Due to the frequent diagnosis of benign thyroid nodules, it is necessary to deviate from the traditional paradigm based on frequent surgical treatment. This article highlights the evolution of diagnosis and treatment in recent years, beginning from standardization of ultrasound assessment of nodules and cytology results to minimally invasive techniques to reduce the size of symptomatic thyroid nodules. These achievements reduce the number of surgeries, enable more individualized care for patients with benign thyroid disease, reduce long-term complications, and promote cost-effectiveness within healthcare systems. Furthermore, although the use of minimally invasive techniques significantly decreases thyroid nodule volume, the thyroid nodule usually does not disappear and the challenges in this field are discussed (the efficacy of thermal ablation, a variable part of thyroid nodules that remains viable after thermal ablation, some of the nodules treated with thermal ablation may require a second treatment over time and the efficacy of thermal ablation in nodules with different phenotypes). However, although surgery still represents the "gold standard" for establishing the final histopathologic diagnosis, it is associated with lifelong thyroid hormone substitution need and serious complications in rare cases. Therefore, it should represent the ultima ratio only after a detailed diagnostic procedure. In the future, artificial intelligence-assisted programs for the evaluation and management of nodules are expected.

Factors Influencing the Duration of Maintenance Therapy in Metastatic Colorectal Cancer

BACKGROUND/OBJECTIVES

Metastatic colorectal cancer (mCRC) is mainly treated with 5-Fluoro-Uracil (5-FU), Oxaliplatin and Irinotecan chemotherapies and anti-Epidermal Growth Factor Receptor (EGFR) or anti-Vascular Endothelial Growth Factor (VEGF) targeted therapies. Due to chemotherapy-related toxicity, patients receive induction treatment to achieve tumour response followed by maintenance therapy with less cytotoxic molecules or a chemotherapy-free interval to reduce chemotherapy-related toxicity. In this study, the aim was to determine the patient, cancer and treatment factors that influence the duration of maintenance therapy (DMT).

METHODS

We collected retrospective data on a cohort of 133 patients treated at the Centre Georges François Leclerc (CGFL) cancer centre in Dijon between March 2014 and June 2022. Patients had unresectable or potentially resectable diseases. They received first-line induction treatment with chemotherapy and/or targeted therapy and maintenance treatment, defined as the interruption of at least one chemotherapy agent.

RESULTS

In the multivariate analysis, age (HR: 1.02, 95% CI 1.00-1.04, p = 0.031), N2 nodal status (HR: 1.78, 95% CI 1.09-2.89, p = 0.021) and the presence of peritoneal metastases (HR: 2.05, 95% CI 1.25-3.36, p = 0.004), as well as baseline carcino-embryonic antigen (CEA) level (HR: 1.10, 95% CI 1.00-1.20, p = 0.052), were significantly associated to poor DMT. Local treatment of liver metastases also significantly reduced the DMT (HR: 0.49, 95% CI 0.28-0.86, p = 0.013). In our cohort, induction triplet chemotherapy significantly increased the CEA delta (70% vs. 44%, p = 0.047) compared to doublet chemotherapy and led to a higher rate of liver surgery (40% vs. 21%, p = 0.014) and a trend for a higher rate of local treatment of metastases (62% vs. 45%, p = 0.059).

CONCLUSIONS

Duration of maintenance therapy is determined by the initial patient and colorectal cancer characteristics. However, it is significantly increased by local treatment of liver metastases. By reducing the tumour burden, a triplet induction chemotherapy regimen increases the rate of liver metastase resection.

Challenges in Diagnosing Focal Liver Lesions Using Contrast-Enhanced Ultrasound

Background: Contrast-enhanced ultrasound (CEUS) has become the preferred method for many clinicians in evaluating focal liver lesions (FLLs) initially identified through standard ultrasound. However, in clinical practice, certain lesions may deviate from the typical enhancement patterns outlined in EFSUMB guidelines. Methods: This study aims to assess FLLs that remained inconclusive or misdiagnosed after CEUS evaluation, spanning eight years of single-center experience. Following CEUS, all FLLs underwent secondary imaging (CT, MRI) or histopathological analysis for diagnostic confirmation. Results: From the initial 979 FLLs, 350 lesions (35.7%) were either inconclusive or misdiagnosed by CEUS, with hepatocellular carcinoma (HCC) and liver metastases constituting the majority of these cases. The most frequent enhancement pattern in inconclusive lesions at CEUS was hyper-iso-iso. Factors such as advanced liver fibrosis, adenomas, and cholangiocarcinoma were significantly associated with higher rates of diagnostic inaccuracies. Conclusions: Advanced liver fibrosis, adenomas, and cholangiocarcinoma were significantly associated with increased diagnostic challenges, emphasizing the need for supplementary imaging techniques.

Configuring thermal ablation volumes for treatment of distinct tumor shapes: a repeatability study using a robotic approach

Objectives

In the current clinical practice of thermal ablation treatment for liver tumors, achieving consistent and effective clinical outcomes across tumors of varying shapes, sizes and locations remains challenging. The aim of this study was to evaluate the repeatability of a novel robotic approach for configurable ablation of distinct tumor shapes and compare it to the standard ablation technique for creating ellipsoidal ablation volumes.

Materials and methods

The repeatability was evaluated in terms of width variability in created ablation volumes. Using a robotic navigation platform, custom ablation profiles configured with power, time, and distance parameters were designed to create four distinct ablation shapes. The profiles were applied for microwave ablation in a tissue-mimicking liver model. For comparison of ablation shape variability, six standard ellipsoidal shapes were created using the standard ablation technique by configuring power and time parameters. For each sample, the resulting ablation area was segmented, and the resulting shape width and length were calculated at the measurement points. Width variability was calculated as the median of the absolute pairwise differences in width at each measurement point, and configurable versus standard ablation shapes were compared using the Mann-Whitney U test.

Results

All tissue-mimicking samples were successfully ablated using both configurable (n = 48) and standard ablation technique (n = 35). Study findings revealed noninferiority regarding repeatability of created ablation shapes using the robotic platform for configurable ablation, compared to created standard ellipsoidal ablation shapes (p < 0.001, 95% CI ≤ -0.05 mm, Δ = -0.22 mm). Median repeatability of created configurable shapes was 1.00 mm, and for standard shapes 1.22 mm. Maximal repeatability for both groups was below 3 mm.

Conclusion

The repeatability of configurable ablation shapes was observed to be noninferior to the standard ablation shapes. Achieving configurable ablation volumes underscores the potential to advance personalization of thermal ablation treatment and broaden its applicability to distinct tumor cases. In-vivo validation is needed for evaluation of the clinical implications of this novel treatment technique.

In vivo imaging and pharmacokinetics of percutaneously injected ultrasound and X-ray imageable thermosensitive hydrogel loaded with doxorubicin versus free drug in swine

Intratumoral injections often lack visibility, leading to unpredictable outcomes such as incomplete tumor coverage, off-target drug delivery and systemic toxicities. This study investigated an ultrasound (US) and x-ray imageable thermosensitive hydrogel based on poloxamer 407 (POL) percutaneously delivered in a healthy swine model. The primary objective was to assess the 2D and 3D distribution of the hydrogel within tissue across three different needle devices and injection sites: liver, kidney, and intercostal muscle region. Secondly, pharmacokinetics of POL loaded with doxorubicin (POLDOX) were evaluated and compared to free doxorubicin injection (DOXSoln) with a Single End Hole Needle. Utilizing 2D and 3D morphometrics from US and x-ray imaging techniques such as Computed Tomography (CT) and Cone Beam CT (CBCT), we monitored the localization and leakage of POLDOX over time. Relative iodine concentrations measured with CBCT following incorporation of an iodinated contrast agent in POL indicated potential drug diffusion and advection transport. Furthermore, US imaging revealed temporal changes, suggesting variations in acoustic intensity, heterogeneity, and echotextures. Notably, 3D reconstruction of the distribution of POL and POLDOX from 2D ultrasound frames was achieved and morphometric data obtained. Pharmacokinetic analysis revealed lower systemic exposure of the drug in various organs with POLDOX formulation compared to DOXSoln formulation. This was demonstrated by a lower area under the curve (852.1 ± 409.1 ng/mL·h vs 2283.4 ± 377.2 ng/mL·h) in the plasma profile, suggesting a potential reduction in systemic toxicity. Overall, the use of POL formulation offers a promising strategy for precise and localized drug delivery, that may minimize adverse effects. Dual modality POL imaging enabled analysis of patterns of gel distribution and morphology, alongside of pharmacokinetics of local delivery. Incorporating hydrogels into drug delivery systems holds significant promise for improving the predictability of the delivered drug and enhancing spatial conformability. These advancements can potentially enhance the safety and precision of anticancer therapy.