Subcapsular Location Research Articles

Assessment of real-time US-CT/MR-guided percutaneous gold fiducial marker implementation in malignant hepatic tumors for stereotactic body radiation therapy

Backgrounds/Aims: This study explored the initial institutional experience of using gold fiducial markers for stereotactic body radiotherapy (SBRT) in treating malignant hepatic tumors using real-time ultrasound-computed tomography (CT)/magnetic resonance (MR) imaging fusion-guided percutaneous placement.Methods: From May 2021 to August 2023, 19 patients with 25 liver tumors that were invisible on pre-contrast CT received fiducial markers following these guidelines. Postprocedural scans were used to confirm their placement. We assessed technical and clinical success rates and monitored complications. The implantation of fiducial markers facilitating adequate treatment prior to SBRT, which was achieved in 96% of the cases (24 of 25 tumors), was considered technical success. Clinical success was the successful completion of SBRT without evidence of marker displacement and was achieved in 88% of cases (22 of 25 tumors). Complications included one major subcapsular hematoma and marker migration into the right atrium in two cases, which prevented SBRT.Results: Among the treated tumors, 20 of 24 (83.3%) showed a complete response, three of 24 (12.5%) remained stable, and one of 24 (4.2%) progressed during an average 11.7-month follow-up (range, 2-32 months).Conclusions: This study confirms that percutaneous gold fiducial marker placement using real-time CT/MR guidance is effective and safe for SBRT in hepatic tumors, but warns of marker migration risks, especially near the hepatic veins and in subcapsular locations. Using fewer markers than traditionally recommended-typically two per patient, the outcomes were still satisfactory, particularly given the increased risk of migration when markers were placed near major hepatic veins.

Preoperative Clinical and Ultrasonographic Predictors for Aggressive Behaviors in Sporadic Medullary Thyroid Carcinomas.

Objective: To explore the clinical and ultrasonographic predictors for aggressive behaviors preoperatively in sporadic medullary thyroid carcinomas (MTCs). Materials and Methods: The preoperative clinical and ultrasonographic characteristics of patients diagnosed with MTCs between January 2009 and May 2022 were retrospectively reviewed. MTCs were described and categorized according to the American College of Radiology (ACR) thyroid imaging reporting and data system classification by 2 radiologists. Interobserver agreement was evaluated by kappa test. Univariate and multivariate analyses were performed to identify predictors of aggressive behaviors in MTCs. The log-rank test was utilized to compare differences in Kaplan-Meier (K-M) curves for postoperative disease-free survival (PDFS). Results: A total of 120 patients were enrolled in the final study. Male sex was significant risk factor for metastasis, perithyroidal invasion, and lateral cervical lymph node (LCLN) metastasis [odds ratio (OR): 3.109, P = .019; OR: 5.316, P = .018; OR: 5.154 P = .012, respectively]. The kappa values for all ultrasonic characteristics were high (ranged from 0.811 to 0.941). Size, focality, and margin of the nodule were independent risk factors for metastasis, as well as for LCLN metastasis. Whereas margin (P < .001) and a subcapsular location (P = .021) were risk factors for perithyroidal invasion. According to K-M analysis, PDFS of patients differed significantly between groups with/without metastasis (P < .001), groups with/without perithyroidal extension (P < .001) and groups with/without LCLN metastasis (P < .001). Conclusions: Male sex is an independent risk factor for metastasis, perithyroidal invasion, and LCLN metastasis. The large size (≥2.55 cm for metastasis, ≥2.15 cm for LCLN metastasis, respectively), multifocality, and irregular margin of nodules were independent risk factors for both metastasis and LCLN metastasis. Extrathyroidal extension and a subcapsular location were risk factors for perithyroidal invasion. Moreover, patients with metastasis/perithyroidal extension/LCLN metastasis exhibited worse PDFS.

A new histopathological location of parathyroid gland with high possibility of unintended parathyroidectomy.

Unintended parathyroidectomy occasionally happens despite meticulous capsular dissection and the histopathological location of removed parathyroid glands were traditionally classified as extracapsular, subcapsular, and intrathyroidal location. This study aimed to investigate the new histopathological location of parathyroid gland with high possibility of unintended parathyroidectomy that was difficult to be found with naked eye despite capsular dissection. This study investigated unintended parathyroidectomy that occurred in 743 patients who received thyroid surgery by reviewing pathology reports and slides. The histopathological location of unintentionally removed parathyroid glands was classified as intracapsule and extracapsule, and the intracapsular glands were further classified as completely buried in the thyroid parenchyme, partially buried, and subcapsular locations. The incidence of unintended parathyroidectomy was 12.8%. Among the 103 unintentionally removed parathyroid glands, 74 (71.8%) were found intracapsular and 29 were extracapsular. Among the intracapsular glands, 57 (55.4%) parathyroid glands were found in difficult locations such as completely buried (40.8%) and partially buried (14.6%). The partially buried parathyroid gland can act as a risk factor for unintended parathyroidectomy comparable to intrathyroidal parathyroid gland despite the surgeon's best effort with meticulous capsular dissection. However, continued advances in visualizing technique such as autofluorescence imaging may lower the chance of incidentally removed partially buried parathyroid glands in the future.

Ultrasound and demographic predictors of papillary thyroid cancer local metastasis at the preoperative stage: a predictive model

Background. Due to the low sensitivity and specificity of neck ultrasound in the evaluation of the central lymph nodes, it is necessary to find alternative ways to predict central lymph node metastases in patients with papillary thyroid cancer (PTC). The purpose of the study is to develop a prognostic model for assessing the risk of local metastasis of papillary thyroid cancer based on preoperative ultrasound and demographic predictors. Materials and methods. A retrospective monocenter cohort study was conducted. The data of 401 patients who underwent surgery for PTC were processed. The main group included 179 patients in whom central lymph node metastases were detected during histopathological examination. The comparison group consisted of 222 patients without metastases according to the results of histopathological examination. When conducting the analysis, the following signs were considered as risk factors: subcapsular location of the tumor; size; blurred boundaries; the presence of calcification areas (microcalcifications); age of a patient. Inclusion criteria: PTC that was cytologically confirmed at the preoperative stage; surgeries (thyroidectomy/hemithyroidectomy and central neck lymph node dissection). Exclusion criteria: history of neck surgery; multifocal lesions of the thyroid gland. Results. The following logistic equation was obtained using the StatPlus program: y = –1.839 – 0.037 × X1 + 0.097 × X2 + 1.123 × X3 + 1.198 × X4 + + 0.692 × X5, where X1, X2, X3, X4, X5 are age (years), size (mm), subcapsular location (presence), blurred boundaries (presence), calcifications (presence), respectively. The obtained prognostic model provided the following operational characteristics when specifying the threshold value for P, which is equal to 0.44 (the decisive rule X &gt; T): sensitivity — 75.4 %, specificity — 79.3 %, diagnostic efficiency — 75.1 %. To assess the quality of the model, the receiver operator characteristic (ROC) analysis was performed. The following data were obtained: area under the ROC curve = 0.797 (95% confidence interval: 0.753–0.841), which corresponds to the good quality of the model, and Youden index J = 0.5155. Checking the quality of the model on a control group of 100 people gave the following results: sensitivity — 72.2 %, specificity — 76.1 %, diagnostic efficiency — 75.8 %. Conclusions. The application of a prognostic model based on ultrasound data and the patient’s age makes it possible to predict the presence of local metastases of the PTC at the preoperative stage with a diagnostic efficiency of 75.8 %. No prognostic model gives 100% prediction accuracy. When choosing the treatment, additional influencing factors (history of radiation exposure, burdened family history, etc.) for a specific patient should be considered.

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.

Long-Term Outcomes and Risk Factors of Radiofrequency Ablation for T1N0M0 Papillary Thyroid Carcinoma

Radiofrequency ablation (RFA) has gained increasing interest as a minimally invasive procedure to treat low-risk papillary thyroid carcinoma (PTC). Considering the indolent nature of this disease, studies in large populations with long follow-up would be invaluable to further substantiate the effectiveness of RFA. To evaluate the long-term (58.5 months) outcomes of patients with T1N0M0 PTC who underwent RFA and investigate risk factors for local tumor progression (LTP). This cohort study included 1613 patients aged 18 years or older with T1N0M0 PTC who underwent ultrasonography-guided RFA between January 2014 and December 2020 at the Chinese People's Liberation Army General Hospital in Beijing, China. Included in the analysis were patients with PTC (confirmed by biopsy) with a maximum diameter of 20 mm or less; no evidence of extrathyroidal extension (capsular disruption or involvement of perithyroidal tissue), lymph node metastasis, or distant metastasis on ultrasonography or computed tomography; and no evidence of an aggressive subtype of PTC on biopsy. Patients with PTC larger than 2 cm, less than 12 months of follow-up, or inadequate follow-up information were excluded. Data were analyzed in April 2023. Long-term progression rate, disease-free survival, and complete tumor disappearance and their associations with patient and tumor characteristics. Disease-free survival was calculated using Kaplan-Meier analysis. Cox proportional hazards regression analyses were performed to assess risk factors for LTP and complete tumor disappearance. The study comprised 1613 patients (mean [SD] age, 43.3 [10.2] years; 1256 women [77.9%]) with 1834 T1N0M0 PTC tumors. During a mean follow-up of 58.5 months (range, 27 to 111 months), LTP was observed in 69 patients (4.3%), including 42 (2.6%) with tumor recurrence and 27 (1.7%) with tumor persistence. Cumulative disease-free survival rates at 1, 3, 5, and 8 years were 98.0%, 96.7%, 96.0%, and 95.7%, respectively. The overall complication rate was 2.0% (32 patients), with 6 (0.4%) major complications. Independent risk factors for LTP included subcapsular tumor location 2 mm or less from the capsule or trachea (hazard ratio [HR], 3.36; 95% CI, 2.02-5.59; P < .001) and multifocal tumors (HR, 2.27; 95% CI, 1.30-3.96; P = .004). Furthermore, 1376 patients (85.3%) showed complete tumor disappearance at follow-up ultrasonographic examination. Factors associated with complete tumor disappearance included age 40 years or less (HR, 0.78; 95% CI, 0.70-0.87; P < .001), stage T1a tumors (HR, 0.37; 95% CI, 0.31-0.45; P < .001), and unifocal tumors (HR, 0.50; 95% CI, 0.42-0.60; P < .001). In this cohort study, ultrasonography-guided RFA for T1N0M0 PTC had excellent long-term outcomes. Patients with unifocal T1N0M0 PTC and subcapsular tumor location more than 2 mm from the capsule or trachea may be the best candidates for RFA.

Feasibility and safety of bipolar radiofrequency track cautery during percutaneous image-guided abdominal biopsy procedures.

The purpose of this study was to assess the feasibility and safety of using a bipolar radiofrequency track cautery device during percutaneous image-guided abdominal biopsy procedures in at-risk patients. Forty-two patients (26-79 years old; female 44%) with at least one bleeding risk factor who underwent an abdominal image-guided (CT or US) biopsy and intended bipolar radiofrequency track cautery (BRTC) were retrospectively studied. An 18G radiofrequencyelectrode was inserted through a 17G biopsy introducer needle immediately following coaxial 18G core biopsy, to cauterize the biopsy track using temperature control. Bleeding risk factors, technical success, and adverse events were recorded. BRTC was technically successful in 41/42 (98%) of procedures; in one patient, the introducer needle retracted from the liver due to respiratory motion prior to BRTC. BRTC following percutaneous biopsy was applied during 41 abdominal biopsy procedures (renal mass = 12, renal parenchyma = 10, liver mass = 9, liver parenchyma = 5, splenic mass or parenchyma = 4, gastrohepatic mass = 1). All patients had one or more of the following risk factors: high-risk organ (spleen or renal parenchyma), hypervascular mass, elevated prothrombin time, renal insufficiency, thrombocytopenia, recent anticoagulation or anticoagulation not withheld for recommended interval, cirrhosis, intraprocedural hypertension, brisk back bleeding observed from the introducer needle, or subcapsular tumor location. No severe adverse events (grade 3 or higher) occurred. Two (2/41, 5%) mild (grade 1) bleeding events did not cause symptoms or require intervention. Bipolar radiofrequency track cautery was feasible and safe during percutaneous image-guided abdominal biopsy procedures. IRB approval: MBG 2022P002277.

Radiofrequency ablation of subcapsular versus nonsubcapsular hepatocellular carcinomas ≤ 3cm: analysis of long-term outcomes from two large-volume liver centers.

To compare the safety and efficacy of RFA for single HCCs ≤ 3cm in subcapsular versus nonsubcapsular locations using a propensity score matched analysis. This retrospective study included patients with solitary HCCs ≤ 3cm in size who underwent percutaneous RFA from 2005 to 2015 as initial treatment at two large-volume liver centers. Patients were divided into two groups, consisting of those with subcapsular and nonsubcapsular tumor locations. Complications, local tumor progression (LTP), and overall survival (OS) were compared in these two groups before and after propensity score matching (PSM). The study population consisted of 964 patients (712 men [74%]) of mean age 58.3years. Of these 964 patients, 561 (58%) had nonsubcapsular and 403 (42%) had subcapsular HCCs. PSM generated 402 pairs of patients. Major complication rate was low, but significantly higher in the subcapscular group (p = 0.047). Rates of technical effectiveness in these two groups were 99% and 98%, respectively (p = 0.315). However, during follow-up, cumulative 1-, 3-, 5-, and 10-year LTP and OS rates did significantly differ in both entire and PSM cohorts, resulting in the latter 8%, 15%, 20%, and 26% in the nonsubcapsular group vs. 13%, 24%, 30%, and 31% in the subcapsular group (p = 0.015), and 99%, 91%, 80%, and 59% vs. 98%, 85%, 73%, and 50% in the two groups (p = 0.004), respectively. Rates of major complications, LTP, and OS differed significantly following first-line RFA treatment of single HCCs ≤ 3cm in favor of the nonsubcapsular locations. This large-scale study provides evidence that radiofrequency ablation for small (≤ 3cm) hepatocellular carcinomas is safer and more effective in nonsubcapsular location than in subcapsular location. • There exist conflicting outcomes on the effectiveness of RFA for early HCC depending on tumor location. • Rate of local tumor progression was significantly higher in the subcapsular hepatocellular carcinomas. • Overall survival rate was significantly poorer in the subcapsular hepatocellular carcinomas.

Predicting Infectious Complications after Percutaneous Thermal Ablation of Liver Malignancies: A 12-year Single-Center Experience.

Background Infectious complications after percutaneous thermal ablation are seldom discussed, but better understanding of risk factors and early prediction is critical. Purpose To estimate the incidence of infectious complications after percutaneous thermal ablation of liver malignancies and to develop prediction models. Materials and Methods This single-center retrospective study reviewed the data of 3167 patients who underwent 7545 percutaneous US-guided thermal ablation procedures of liver malignancies between January 2010 and January 2022. All procedures with infectious complications were included as the case group. For each case, one treatment date-matched control subject without infection was randomly selected following a nested case-control design. Independent factors of overall and hepatobiliary infection were investigated with multivariable logistic regression. Results A total of 80 patients (median age, 59 years; IQR, 51-68 years; 64 men, 16 women) developed infectious complications after 80 ablation procedures; the incidence was 1.1% (80 of 7545 procedures). Of those with infection, 18% (14 of 80 patients) were severe, and 10% (eight of 80 patients) died as a result. Independent risk factors for overall infectious complication included prior biliary intervention (odds ratio [OR], 18.6; 95% CI: 4, 86; P < .001), prior transarterial chemoembolization (TACE) (OR, 2.4; 95% CI: 1.0, 5.8; P = .045), and the largest tumor size (OR, 1.9; 95% CI: 1.3, 2.8; P = .002); on this basis, subcapsular location was an additional risk factor of hepatobiliary infection. Prediction models for overall and hepatobiliary infection had an area under the receiver operating characteristics curve (AUC) of 0.77 and 0.82, respectively, both of which showed better AUC compared with the models, including prior biliary intervention alone (AUC = 0.63 and 0.65, respectively; P = .01 and P = .005, respectively). Conclusion Infectious complications after percutaneous thermal ablation of liver malignancies were uncommon but potentially fatal. Independent predictors were prior biliary intervention, prior transarterial chemoembolization, and the largest tumor size. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Ben-Arie and Sosna in this issue.

Factors associated with increased risk of peritoneal seeding after radiofrequency ablation for hepatocellular carcinoma.

To evaluate the incidence, risk factors, and prognosis associated with peritoneal seeding after percutaneous radiofrequency ablation (RFA) for HCC, focusing on viable tumors after previous locoregional treatment, including TACE and RFA. Exactly 290 patients (mean age, 67.9years ± 9.74; 223 men) with 383 HCCs (mean size, 15.9mm ± 5.49) who underwent RFA between June 2012 and December 2019 were included in this retrospective study. Among them, 158 had history of previous treatment (mean number, 1.3 ± 1.8) with 109 viable HCCs. Cumulative seeding after RFA was estimated using the Kaplan-Meier method. Independent factors affecting seeding were investigated using multivariable Cox proportional hazards regression analysis. Median follow-up was 1175days (range: 28-4116). Seeding incidence was 4.1 (12/290) and 4.7% (17/383) per patient and tumor, respectively. The median time interval between RFA and detection of seeding was 785days (range: 81-1961). Independent risk factors for seeding included subcapsular tumor location (hazard ratio [HR] 4.2; 95% confidence interval [CI] 1.4, 13.0; p = 0.012) and RFA for viable HCC after previous locoregional treatment (HR 4.5; 95% CI 1.7, 12.3; p = 0.003). Subgroup analysis for viable tumors, revealed no significant difference in cumulative seeding rates between the TACE and RFA groups (p = 0.078). Cumulative overall survival rates differed significantly between patients with and without seeding metastases (p < 0.001). Peritoneal seeding after RFA is a rare, delayed complication. Subcapsular-located and viable HCC after previous locoregional treatment are potential risk factors for seeding. Seeding metastases could affect the prognosis of patients who cannot receive local therapy.

Rates and Patterns of Recurrence After Microwave Ablation of Colorectal Liver Metastases: A Per Lesion Analysis of 416 Tumors in the Era of 2.45GHz Generators.

For some patients with colorectal liver metastases (CRLMs), surgical resection of all visible disease can lead to long-term survival and even cure. When complete resection is not feasible, microwave ablation (MWA) can help achieve hepatic disease control. As modern 2.45-GHz MWA generators gain popularity, the characteristics of tumors most likely to benefit from this method remain unclear. This study aimed to evaluate local recurrence (LR) rates, patterns of recurrence, and factors contributing to treatment failure after 2.45-GHz MWA of CRLM. Patients with CRLM who underwent operative 2.45-GHz MWA between 2011 and 2019 were identified in a prospectively maintained single-institution database. Recurrence outcomes were ascertained for each lesion by imaging review. Factors associated with LR were analyzed. The study enrolled 184 patients bearing 416 ablated tumors. Most of the patients (65.8%) had high clinical risk scores (3-5), and 165 (90%) underwent concurrent liver resection. The median tumor size was 10 mm. After a median follow-up period of 28.8 months, LR was observed in 45 tumors, and the cumulative incidence of LR at 24 months was 10.9% (95% confidence interval [CI], 8.0-14.3%]. In 7%, LR was the first recurrence site, often combined with recurrence elsewhere. The cumulative incidence of LR at 24 months was 6.8% (95% CI 3.8-11.0%) for tumors 10 mm in size or smaller, 12.4% (95% CI 7.8-18.1%) for tumors 11 to 20 mm in size, and 30.2% (95% CI 14.2-48.0%) for tumors larger than 20 mm. In the multivariable analysis, tumors larger than 20 mm with a subcapsular location were significantly associated with increased LR risk. Treatment of CRLM with 2.45-GHz MWA offers excellent local control at 2 years and is most successful for small tumors deep within the parenchyma.

Transarterial Chemoembolization Combined with Simultaneous Thermal Ablation for Solitary Hepatocellular Carcinomas in Regions with a High Risk of Recurrence.

We evaluated the safety and efficacy of transarterial chemoembolization combined with percutaneous thermal ablation (radiofrequency or microwave ablation) in the treatment of solitary hepatocellular carcinoma tumors ranging from 2 to 4.5 cm at subdiaphragmatic, subcapsular, or perivascular locations. Fifteen patients (12 men, mean [range] age of 66.6 ± 10.88 [34-75] y) who received transarterial chemoembolization combined with simultaneous percutaneous radiofrequency ablation (n = 5) or microwave ablation (n = 10) for hepatocellular carcinoma in regions with high risk of recurrence (subdiaphragmatic, subcapsular, or perivascular) between 2012 and 2018 were evaluated. We retrospectively investigated tumor diameter and localization, success rate, safety, local efficacy (imaging at month 1 after treatment), local tumor response (3 months posttreatment), local tumor progression, intrahepatic distant recurrence, overall survival and complications. Tumor diameter ranged from 20 to 45 mm (mean 31.7 ± 7.37 mm). Hepatocellular carcinoma diameter was 2 to 3 cm in 7 patients and 3.1 to 4.5 cm in 8 patients. The technical success rate was 100%, with no life-threatening complications. At enhanced imaging at 1-month follow-up, the complete necrosis rate was 100%; at 3 months, 100% of patients had a complete response. During a mean follow-up of 26 ± 13.6 months, 7 patients (46.7%) had tumor progression. Three patients (20%) had local tumor response, and 4 patients (26.7 %) experienced distant recurrences in the untreated liver. The mean local tumor progression and mean intrahepatic distance recurrence times were 11 months and 29.5 months, respectively. Overall survival rates were 100% at 1 year, 73% at 3 years, and 47% at 5 years. Transarterial chemoembolization combined with simultaneous percutaneous thermal ablation is safe, feasible, and effective in enhancing the local control rate for solitary hepatocellular carcinoma ranging from 2 to 4.5 cm in regions with high risk of recurrence.

Retrospective Evaluation and Significance of Neutrophil-to-Lymphocyte Ratio Prior to and 1 month Following Microwave Ablation of Hepatocellular Carcinoma.

Neutrophil-to-lymphocyte ratio (NLR) recently demonstrated predictive value for hepatocellular carcinoma (HCC) recurrence after thermal ablation. Microwave ablation (MWA) has been shown to induce changes in the immune landscape after HCC treatment. This study aims at identifying predictors of local tumor progression (LTP) and post-treatment NLR kinetics after MWA. Data from 108 consecutive patients who underwent percutaneous MWA of 119 HCCs with a 2450Hz/100W generator in two institutions from October 2014 to September 2021 were retrospectively reviewed. Forty-five HCCs (42 patients) met inclusion criteria for analysis (technique efficacy, pre- and post-treatment NLR availability, follow-up > 6months, absence of complications). NLR was analyzed prior to therapy and at 1-month follow-up; difference between the two time points was defined as ΔNLR1stFU. After a median follow-up of 25months, LTP occurred in 18 HCCs (40%) and 18 patients (42.9%). Multivariate competing risk regression comprising ΔNLR1stFU > 0, cirrhosis etiology and subcapsular location showed that the only independent predictor of LTP was ΔNLR1stFU > 0, on both a per-patient (HR = 2.7, p = 0.049) and per-tumor (HR = 2.8, p = 0.047) analysis. ΔNLR1stFU > 0 occurred in 24/42 patients (57.1%). In this subgroup, higher rates of female patients (p = 0.026), higher mean baseline NLR (p < 0.0001) and lower mean energy/size (p = 0.006) were observed. Upon ROC curve analysis, energy/size < 1414J/mm predicted ΔNLR1stFU > 0 with 76% sensitivity and 70% specificity (AUC = 0.74). NLR increase after ablation was the only independent predictor of LTP, supporting the role of balance between systemic inflammation and immunity in recurrence after MWA. Ablation energy/tumor size predicted NLR increase, reinforcing the concept of immune ablation. III.

Tumor location influences perioperative and oncologic outcomes in solitary intrahepatic cholangiocarcinoma following curative resection: a multi-center analysis.

To compare perioperative and oncologic outcomes of patients with different locations of intrahepatic cholangiocarcinoma (ICC). A total of 352 ICC patients underwent curative intent hepatectomy were included. Clinical outcomes were compared between ICC patients with tumors located at subcapsular and non-subcapsular, perihepatic vein (pHV) and non-pHV, or periportal vein (pPV) and non-pPV. Kaplan-Meier curves were used to evaluate the influence of tumor location on survival outcomes. Surgical procedures for pPV ICC were associated with longer operative time and elevated intraoperative blood loss compared to non-pPV. Patients with pPV ICC significantly correlated to increased frequency of log odds of positive lymph nodes (LODDS) classification 3-4. In addition, the ICC located at pPV was correlated with both worse overall survival (OS) and disease-free survival (DFS) compared to non-pPV, whereas no significant difference was observed between subcapsular and non-subcapsular or between pHV and non-pHV. A pPV location contributed to poor perioperative outcomes and quick tumor recurrence for patients with solitary ICC undergoing curative resection. A pPV location also contributed to regional lymph node metastases and was a risk factor for intrahepatic recurrence. Subcapsular and pHV locations did not influence clinical outcomes of ICC patients.

Volumetric analyses of ablation dimensions in microwave ablation for colorectal liver metastases

Background In thermal ablation of malignant liver tumors, ablation dimensions remain poorly predictable. This study aimed to investigate factors influencing volumetric ablation dimensions in patients treated with stereotactic microwave ablation (SMWA) for colorectal liver metastases (CRLM). Methods Ablation volumes from CRLM ≤3 cm treated with SMWA within a prospective European multicentre trial were segmented. Correlations between applied ablation energies and resulting effective ablation volumes (EAV) and ablation volume irregularities (AVI) were investigated. A novel measure for AVI, including minimum enclosing and maximum inscribed ellipsoid ablation volumes, and a surrogate parameter for the expansion of ablation energy (EAV per applied energy), was introduced. Potential influences of tumor and patient-specific factors on EAV per applied energy and AVI were analyzed using multivariable mixed-effects models. Results A total of 116 ablations from 71 patients were included for analyses. Correlations of EAV or AVI and ablation energy were weak to moderate, with a maximum of 25% of the variability in EAV and 13% in AVI explained by the applied ablation energy. On multivariable analysis, ablation expansion (EAV per applied ablation energy) was influenced mainly by the tumor radius (B = −0.03, [CI –0.04, –0.007]). AVI was significantly larger with higher applied ablation energies (B = 0.002 [CI 0.0007, 0.002]]); liver steatosis, KRAS mutation, subcapsular location or proximity to major blood vessels had no influence. Conclusions This study confirmed that factors beyond the applied ablation energy might affect volumetric ablation dimensions, resulting in poor predictability. Further clinical trials including tissue sampling are needed to relate physical tissue properties to ablation expansion.

Imaging features of biliary adenofibroma of the liver with malignant transformation: a case report with literature review

BackgroundBiliary adenofibroma (BAF) is a rare primary hepatic tumor with the potential risk of malignant transformation. Given the extreme rarity of the disease, the imaging features of BAF are unclear. We presented a case of malignant BAF and conducted a systematic literature review. We highlighted the key imaging features in the diagnosis and aggressiveness assessment of BAF, as well as the role of various imaging modalities in evaluating BAF.Case presentationWe reported a 64-year-old woman with a 5-months history of pain in the right upper quadrant abdomen. US of the liver showed a hypoechoic subcapsular nodule. CT scan revealed a subcapsular solid-cystic mass in segment V of the liver. The mass showed a marked enhancement in the arterial phase followed by wash-out in the venous phase. The patient underwent partial resection of liver’s right lobe. The mass was diagnosed as BAF with malignant transformation by postoperative pathology.ConclusionsCT and MRI are helpful in recognizing and characterizing BAF. The imaging features of BAF include a solitary, large solid-cystic mass with a well-defined margin, lobulated shape, and internal septa; subcapsular location; no intrahepatic bile duct communication; the presence of von Meyenberg complexes in background liver. The enhancement patterns may have the potential to assess the aggressiveness of BAF, and that marked enhancement in the arterial phase followed by wash-out in the venous phase is suggestive of malignant BAF.

Clinical characteristics and CT features of hepatic epithelioid haemangioendothelioma and comparison with those of liver metastases

BackgroundTo analyse clinical characteristics and computer tomography (CT) findings of hepatic epithelioid haemangioendothelioma (HEH) and to determine differential features compared with liver metastasis (LM).MethodsThis retrospective study included 80 patients with histopathologically confirmed HEH (n = 20) and LM (n = 60) of different primary tumours who underwent dynamic contrast-enhanced CT scans. CT findings included the location, contour, size, number, margin, and density of lesions, the patterns and degree of contrast enhancement of lesions, vascular invasion and changes in other organs. The enhancement ratio (ER) and tumour-to-normal parenchyma ratio (TNR) were calculated. Receiver operating characteristic curves (ROCs) were used to determine areas under the curve (AUCs).ResultsAbout 65% of HEH lesions were located in submarginal areas. Significant differences were observed between HEH and LM patients in age, sex, and tumour marker positivity (p < 0.05). HEH showed minimal to slight enhancement, thin ring-like enhancement in arterial phase, and slight, homogeneous, progressive enhancement in the portal phase. HEH presented capsule retraction, and the “target” sign and the “lollipop” sign were significantly more frequent than in LM (p < 0.05). The ER and TNR in the arterial phase of HEH were lower than those of LM (p < 0.05). AUCs of ER and TNR in the arterial phase were 0.74 and 0.73, respectively.ConclusionLesions in subcapsular locations, capsular retraction, slight and thin ring-like enhancement, “target” and “lollipop” signs and lower ER and TNR in the arterial phase may represent important features of HEH compared with LM.

Ablation Difficulty Score: Proposal of a new tool to predict success rate of percutaneous ablation for hepatocarcinoma

PurposeIdentify the factors related to failure ablation after percutaneous ultrasound guided single electrode radiofrequency ablation (RFA) for hepatocarcinoma (HCC) and propose a score for improving patient selection and treatment allocation. MethodsFrom 2010 to 2020 585 HCC nodules treated with RFA were prospectively collected. Ablation Difficulty Score (ADS) was built-up according to clinical and radiological factors related to failure ablation identified by Cox-logistic regression analysis. The study population was stratified in low risk (ADS 0), intermediate risk (ADS 1), and high risk (ADS ≥ 2) of failure ablation. ResultsOverall ablation success rate was 85.5%. Morbidity and mortality rates were 3.5% and 0.0%. According to per nodule analysis the following factors resulted related to failure ablation: size > 20 mm (p = 0.002), sub-capsular location (p = 0.008), perivascular location (p = 0.024), isoechoic appearance (p = 0.008), and non-cirrhotic liver (p = 0.009). The ablation success rate was 93.5% in ADS 0, 85.8% in ADS 1 and 71.3% in ADS ≥ 2 (p < 0.001). The 1-year local tumor progression (LTP) free survival was 90.2% in ADS 0, 80.6% in ADS 1, and 72.3% in ADS ≥ 2 (p = 0.009). Nodule’s size > 20 mm (p = 0.014), isoechoic appearance (p = 0.012), perivascular location (p = 0.012) resulted related to lower LTP free survival. ConclusionAblation Difficulty Score could be a simple and useful tool for guiding the treatment decision making of HCC. RFA in high risk nodules (ADS ≥ 2) should be carefully evaluated and reserved for patients not suitable for surgery or liver transplantation.

Invasion of a Recurrent Laryngeal Nerve from Small Well-Differentiated Papillary Thyroid Cancers: Patient Selection Implications for Active Surveillance.

Background: The success of an active surveillance management approach to low-risk papillary thyroid cancer (PTC) is heavily dependent on proper patient selection. For example, primary tumors located in a subcapsular position immediately adjacent to the trachea or a recurrent laryngeal nerve (RLN) are considered to be inappropriate for active surveillance. Since preoperative imaging cannot reliably rule out extrathyroidal extension or reveal the full course of the RLN relative to the thyroid gland, it is important for clinicians to understand subcapsular tumor locations and minimum tumor sizes that are most likely to be associated with gross invasion of the RLNs. Methods: We assessed the medical records of 123 patients treated at Memorial Sloan Kettering Cancer Center (MSK) between 1986 and 2015 who had a primary PTC tumor demonstrating gross extrathyroidal extension to either the right or left RLN. Thirty patients with a primary tumor ≤2 cm in diameter demonstrating extrathyroidal extension into an RLN were included in the analysis. Results: Gross invasion of an RLN by tumors ≤2 cm is a rare event that was seen in only 0.8% (35/4334) of patients with PTC who underwent initial thyroid surgery at MSK between 1986 and 2015. Gross RLN invasion was associated with subcapsular PTC tumors located in either the right paratracheal area (60%), left paratracheal area (36.7%), or right lateral posterior lobe area not adjacent to the trachea (3.3%). Only a quarter of the patients had imaging findings suggestive of extrathyroidal extension and only 30% had clinically apparent vocal paresis/paralysis on preoperative examination. Invasion of the RLN was not observed for primary tumors <0.9 cm in diameter, regardless of tumor location. Conclusions: Well-differentiated PTC tumors ≥0.9 cm in maximal diameter that are located in the right paratracheal, left paratracheal, and right lateral posterior lobe subcapsular positions are usually not appropriate for active surveillance even in the absence of definitive evidence for nerve invasion on preoperative imaging or vocal cord examination. Patient selection for active surveillance management should take into account not only the size and growth rate of a tumor but also its location in relation to the expected course of RLNs.

Hepatic adrenal rest tumor in a patient with multifactorial liver cirrhosis: a case report with CT and MRI findings and pathologic correlation

BackgroundAdrenal rest tumor is an ectopic collection of adrenocortical cells in an extra-adrenal site, more frequently located around the kidney, retroperitoneum, spermatic cord, para-testicular region and broad ligament, but very rarely occurring also in the liver. Hepatic adrenal rest tumor poses a diagnostic challenge in differentiating it from hepatocellular carcinoma, particularly in a cirrhotic liver.Case presentationAn 83-years-old male was referred to our hospital by his family doctor for hepatological evaluation due to multifactorial liver cirrhosis. Ultrasound revealed a centimetric hypoechoic nodule in the VI hepatic segment in the context of a liver with signs of cirrhosis and steatosis. The patient first underwent MRI and then CT, which showed a fat containing focal liver lesion in the subcapsular location of the right lobe, strictly adjacent to the homolateral adrenal gland. The nodule was hypervascular in the arterial phase, washed out in the portal-venous and transitional phases, resulting hypointense in the hepato-biliary phase at MR imaging. In the suspicion of a hepatocellular carcinoma, the nodule was surgically removed, and the patient’s postoperative course was unremarkable. The final histopathological diagnosis was of adrenal rest tumor of the liver.ConclusionsHepatic adrenal rest tumor is an extremely rare hepatic tumor, often without any clinical manifestation, that can also occur in the cirrhotic liver as in our case. Although there are not specific imaging findings, the possible diagnosis of HART should be considered when we observe a well-defined lesion in the subcapsular location of the right lobe, with fat containing, hypervascularity after contrast medium injection and vascular supply from the right hepatic artery.