Treatment Outcomes of Percutaneous Radiofrequency Ablation for Hepatocellular Carcinomas:Effects of the Electrode Type and Placement Method

Objective@#To investigate the association among the electrode placement method, electrode type, and local tumor progression (LTP) following percutaneous radiofrequency ablation (RFA) for small hepatocellular carcinomas (HCCs) and to assess the risk factors for LTP. @*Materials and Methods@#In this retrospective study, we enrolled 211 patients, including 150 males and 61 females, who had undergone ultrasound-guided RFA for a single HCC < 3 cm. Patients were divided into four combination groups of the electrode type and placement method: 1) tumor-puncturing with an internally cooled tip (ICT), 2) tumor-puncturing with an internally cooled wet tip (ICWT), 3) no-touch with ICT, and 4) no-touch with ICWT. Univariable and multivariable Cox proportional-hazards regression analyses were performed to evaluate the risk factors for LTP. The major RFA-related complications were assessed. @*Results@#Overall, 83, 34, 80, and 14 patients were included in the ICT, ICWT, no-touch with ICT, and no-touch with ICWT groups, respectively. The cumulative LTP rates differed significantly among the four groups. Compared to tumor puncturing with ICT, tumor puncturing with ICWT was associated with a lower LTP risk (adjusted hazard ratio [aHR] = 0.11, 95% confidence interval [CI] = 0–0.88, P = 0.034). However, the cumulative LTP rate did not differ significantly between tumorpuncturing with ICT and no-touch RFA with ICT (aHR = 0.34, 95% CI = 0.03–1.62, P = 0.188) or ICWT (aHR = 0.28, 95% CI = 0–2.28, P = 0.294). An insufficient ablative margin was a risk factor for LTP (aHR = 6.13, 95% CI = 1.41–22.49, P = 0.019). The major complication rates were 1.2%, 0%, 2.5%, and 21.4% in the ICT, ICWT, no-touch with ICT, and no-touch with ICWT groups, respectively. @*Conclusion@#ICWT was associated with a lower LTP rate compared to ICT when performing tumor-puncturing RFA. An insufficient ablation margin was a risk factor for LTP.

Percutaneous radiofrequency ablation of hepatocellular carcinoma in a recent cohort at a tertiary cancer center: incidence and factors associated with major complications and unexpected hospitalization events

Purpose@#This study aimed to assess the incidence of and factors associated with major complications, delayed discharge, and emergency room (ER) visits or readmission after percutaneous radiofrequency ablation (RFA) for single hepatocellular carcinoma (HCC) <3 cm in a recent cohort at a tertiary cancer center. @*Methods@#A total of 188 patients with treatment-naïve single HCCs <3 cm who underwent RFA between January 2018 and April 2021 were included in the analysis. Univariable and multivariable logistic regression analyses were performed to identify the factors associated with major complications, delayed discharge, and ER visits or readmission. Local tumor progression (LTP) and overall survival were estimated using the Kaplan-Meier method and Cox proportional-hazards regression analysis. @*Results@#Major complications occurred in 3.2% (6/188) of the patients. The longest diameter of the ablation zone was significantly larger in patients with major complications (P=0.023). Delayed discharge occurred in 5.8% (9/188) of the patients, for which albumin-bilirubin grade 3 was identified as an important determinant. No variables other than major complications were significantly associated with ER visits or readmission, which occurred in 7.0% (13/188) of the patients. Major complications, delayed discharge, and ER visits or readmission were not substantially related to the post-treatment outcomes of LTP and overall survival. @*Conclusion@#This study confirmed RFA as a highly safe procedure for single HCCs <3 cm, despite the rapidly changing RFA techniques in the most recent cohort. A large ablation zone and poor liver function were predictors of major complications and delayed discharge, respectively.

Percutaneous radiofrequency ablation for hepatic metastasis of colorectal cancer: assessment of tumor visibility and the feasibility of the procedure with planning ultrasonography

Purpose@#The aim of this study was to assess the incidence and causes of percutaneous radiofrequency ablation (RFA) infeasibility in cases of metastatic colorectal cancer and to evaluate factors affecting the invisibility of the tumor on planning ultrasonography (US). @*Methods@#This study screened 386 patients who underwent planning US using fusion imaging and/or contrast-enhanced US for percutaneous RFA for suspected metastatic colorectal cancer between January 2013 and December 2020, from whom 136 patients with a single hepatic metastasis from colorectal cancer measuring <3 cm were included. The factors related to the infeasibility of percutaneous RFA were investigated. Univariate and multivariate analyses were performed to assess the factors associated with tumor invisibility on planning US. @*Results@#Among the 136 patients, percutaneous RFA was considered infeasible in 24.3% (33/136) due to a high risk of the heat-sink effect caused by the abutment of a large vessel (n=12), an inconspicuous tumor on planning US (n=11), a high risk of collateral thermal damage to an adjacent organ (n=8), and the absence of a safe electrode path (n=2). In univariate and multivariate analyses, tumor size was a statistically significant factor affecting invisibility on planning US (P=0.003 and P=0.018, respectively). @*Conclusion@#Percutaneous RFA was infeasible in approximately one-fourth of patients with metastatic colorectal cancer. The reason for the infeasibility was mainly an unfavorable tumor location and invisibility on planning US. Small tumor size was the sole significant factor affecting the invisibility of hepatic metastases on planning US.

Direction of Tissue Contraction after Microwave Ablation: A Comparative Experimental Study in Ex Vivo Bovine Liver

Objective@#This study aimed to investigate the direction of tissue contraction after microwave ablation in ex vivo bovine liver models. @*Materials and Methods@#Ablation procedures were conducted in a total of 90 sites in ex vivo bovine liver models, including the surface (n = 60) and parenchyma (n = 30), to examine the direction of contraction of the tissue in the peripheral and central regions from the microwave antenna. Three commercially available 2.45-GHz microwave systems (Emprint, Neuwave, and Surblate) were used. For surface ablation, the lengths of two overlapped square markers were measured after 2.5- and 5-minutes ablations (n = 10 ablations for each system for each ablation time). For parenchyma ablation, seven predetermined distances between the markers were measured on the cutting plane after 5- and 10-minutes ablations (n = 5 ablations for each system for each ablation time). The contraction in the radial and longitudinal directions and the sphericity index (SI) of the ablation zones were compared between the three systems using analysis of variance. @*Results@#In the surface ablation experiment, the mean longitudinal contraction ratio and SI from a 5-minutes ablation using the Emprint, Neuwave, and Surblate systems were 28.92% and 1.04, 20.10% and 0.53, and 24.90% and 0.45, respectively (p < 0.001). A positive correlation between longitudinal contraction and SI was noted, and a similar radial contraction was observed. In the parenchyma ablation experiment, the mean longitudinal contraction ratio and SI from a 10-minutes ablation using the three pieces of equipment were 38.60% and 1.06, 32.45% and 0.61, and 28.50% and 0.50, respectively (p < 0.001). There was a significant difference in the longitudinal contraction properties, whereas there was no significant difference in the radial contraction properties. @*Conclusion@#The degree of longitudinal contraction showed significant differences depending on the microwave ablation equipment, which may affect the SI of the ablation zone.

Percutaneous radiofrequency ablation of solitary hepatic metastases from colorectal cancer: risk factors of local tumor progression-free survival and overall survival

Purpose@#This study aimed to evaluate local tumor progression-free survival (LTPFS) and overall survival (OS) after percutaneous radiofrequency ablation (RFA) for solitary colorectal liver metastases (CLM) <3 cm and to identify the risk factors associated with poor LTPFS and OS after percutaneous RFA. @*Methods@#This study screened 219 patients who underwent percutaneous RFA for CLM between January 2013 and November 2020. Of these, 92 patients with a single CLM <3 cm were included. LTPFS and OS were calculated using the Kaplan-Meier method, and the differences between curves were compared using the log-rank test. Risk factors for LTPFS and OS were assessed using Cox proportional-hazard regression models. @*Results@#Technical efficacy was achieved in the first (n=91) or second (n=1) RFA sessions. During the follow-up (median, 20.0 months), cumulative LTPFS rates at 1, 3, and 5 years were 92.4%, 83.4%, and 76.5%, respectively. During the follow-up (median, 27.8 months), the corresponding OS rates were 97.5%, 81.3%, and 74.8%, respectively. In multivariable Cox regression analyses, the group with both tumor-puncturing RFA and a T4 stage primary tumor (hazard ratio, 3.3; 95% confidence interval, 1.1 to 10.2; P=0.037) had poor LTPFS. In the univariable analysis, no factors were significantly associated with poor OS. @*Conclusion@#Both LTPFS and OS were promising after percutaneous RFA for a single CLM <3 cm. The group with both tumor-puncturing RFA and a T4 stage primary tumor showed poor LTPFS. No risk factors were identified for poor OS.

Laparoscopic radiofrequency ablation versus percutaneous radiofrequency ablation for subphrenic hepatocellular carcinoma

Purpose@#Radiofrequency ablation is a curative treatment option for very early-stage or earlystage hepatocellular carcinoma (HCC). However, percutaneous radiofrequency ablation (PRFA) for subphrenic tumors is technically challenging. Laparoscopic radiofrequency ablation (LRFA) has been used to overcome this disadvantage. This study compared the treatment outcomes between LRFA and PRFA for subphrenic HCC. @*Methods@#This retrospective study screened patients who underwent PRFA or LRFA for subphrenic HCC between 2013 and 2018. Therapeutic outcomes, including local tumor progression (LTP), intrahepatic distant recurrence (IDR), extrahepatic metastasis (EM), disease-free survival (DFS), and overall survival (OS), were compared between the two groups. @*Results@#Thirty patients in the PRFA group and 23 patients in the LRFA group were included. LTP was observed in six patients in the PRFA group (20%), but in no patients in the LRFA group. The cumulative LTP rates at 1, 3, and 5 years were 3.7%, 23.4%, and 23.4%, respectively, in the PRFA group and 0.0% in the LRFA group (P=0.015). The IDR, EM, and DFS rates were not significantly different between the two groups (P=0.304, P=0.175, and P=0.075, respectively). The OS rates at 1, 3, and 5 years were 96.6%, 85.7%, and 71.6%, respectively, in the PRFA group and 100%, 95.7%, and 95.7%, respectively, in the LRFA group (P=0.049). @*Conclusion@#LRFA demonstrated better therapeutic outcomes than did PRFA for subphrenic tumors in terms of LTP and OS. Therefore, LRFA can be considered as the first-line treatment option for subphrenic HCC.

Laparoscopic Hepatic Resection Versus Laparoscopic Radiofrequency Ablation for Subcapsular Hepatocellular Carcinomas Smaller Than 3 cm: Analysis of Treatment Outcomes Using Propensity Score Matching

Objective@#To compare the therapeutic outcomes of laparoscopic hepatic resection (LHR) and laparoscopic radiofrequency ablation (LRFA) for single subcapsular hepatocellular carcinoma (HCC). @*Materials and Methods@#We screened 244 consecutive patients who had received either LHR or LRFA between January 2014 and December 2016. The feasibility of LRFA in patients who underwent LHR was retrospectively assessed by two interventional radiologists. Finally, 60 LRFA-feasible patients who had received LHR and 29 patients who had received LRFA as the first treatment for a solitary subcapsular HCC between 1 cm and 3 cm were finally included. We compared the therapeutic outcomes, including local tumor progression (LTP), recurrence-free survival (RFS), and overall survival (OS) between the two groups before and after propensity score (PS) matching. Multivariable Cox proportional hazard regression was also used to evaluate the difference in OS and RFS between the two groups for all 89 patients. @*Results@#PS matching yielded 23 patients in each group. The cumulative LTP and OS rates were not significantly different between the LHR and LRFA groups after PS matching (p = 0.900 and 0.003, respectively). The 5-year LTP rates were 4.6% and 4.4%, respectively, and OS rates were 100% and 90.7%, respectively. The RFS rate was higher in LHR group without statistical significance (p = 0.070), with 5-year rates of 78.3% and 45.3%, respectively. OS was not significantly different between the LHR (reference) and LRFA groups in multivariable analyses, with a hazard ratio (HR) of 1.33 (95% confidence interval, 0.12–1.54) (p = 0.818). RFS was higher in LHR (reference) than in LRFA without statistical significance in multivariable analysis, with an HR of 2.01 (0.87–4.66) (p = 0.102). @*Conclusion@#There was no significant difference in therapeutic outcomes between LHR and LRFA for single subcapsular HCCs measuring 1–3 cm. The difference in RFS should be further evaluated in a larger study.

Beta 3 Adrenoreceptor Agonist for the Management of Lower Urinary Tract Symptoms in Men With Benign Prostatic Hyperplasia: A Systematic Review / 대한배뇨장애요실금학회지

Beta-3 adrenoceptor (B3AR) agonist which mediate detrusor relaxation has been tried as a new treatment modality for men with benign prostatic hyperplasia (BPH). However, it remains unclear whether the B3AR agonist has more clinical benefits and fewer adverse effects in men with BPH than in women. We performed a comprehensive search using multiple databases, trials registries, other sources of grey literature, and conference proceedings regardless of language or publication status and included randomized controlled trials. Two review authors independently screened the literature, extracted data, and assessed risk of bias. We performed statistical analyses using a random-effects model and interpreted them according to the Cochrane Handbook for Systematic Reviews of Interventions. Primary outcomes were urologic symptom scores, quality of life (QoL), and overall adverse events. We found 4 randomized controlled trials with 1,105 participants in 3 comparisons. All studies reported short-term outcomes (ranged from 8 weeks to 12 weeks). Mirabegron, tamsulosin, silodosin, fesoterodine, and tadalafil were administrated as intervention. While B3AR agonist can improve the patient-important outcomes within group (before and after treatment), B3AR agonist combination therapy with current standard BPH treatment such as alpha blocker or anticholinergic may not have additional effects on urological symptom scores and QoL compared to alpha blocker or anticholinergic monotherapy. B3AR agonist therapy with phosphodiesterase 5 inhibitor (PDE5I) showed statistical improvement on urological symptom scores or QoL compared to PDE5I monotherapy. For safety profile, B3AR agonist in all 3 comparisons may not increase adverse event rate. While B3AR agonists may be used for the treatment of lower urinary tract symptoms in men with BPH if storage symptoms with standard BPH treatment are insufficient, B3AR agonists appear to have trivial or similar effects compared to current standard BPH treatment.

Beta 3 Adrenoreceptor Agonist for the Management of Lower Urinary Tract Symptoms in Men With Benign Prostatic Hyperplasia: A Systematic Review / 대한배뇨장애요실금학회지

Beta-3 adrenoceptor (B3AR) agonist which mediate detrusor relaxation has been tried as a new treatment modality for men with benign prostatic hyperplasia (BPH). However, it remains unclear whether the B3AR agonist has more clinical benefits and fewer adverse effects in men with BPH than in women. We performed a comprehensive search using multiple databases, trials registries, other sources of grey literature, and conference proceedings regardless of language or publication status and included randomized controlled trials. Two review authors independently screened the literature, extracted data, and assessed risk of bias. We performed statistical analyses using a random-effects model and interpreted them according to the Cochrane Handbook for Systematic Reviews of Interventions. Primary outcomes were urologic symptom scores, quality of life (QoL), and overall adverse events. We found 4 randomized controlled trials with 1,105 participants in 3 comparisons. All studies reported short-term outcomes (ranged from 8 weeks to 12 weeks). Mirabegron, tamsulosin, silodosin, fesoterodine, and tadalafil were administrated as intervention. While B3AR agonist can improve the patient-important outcomes within group (before and after treatment), B3AR agonist combination therapy with current standard BPH treatment such as alpha blocker or anticholinergic may not have additional effects on urological symptom scores and QoL compared to alpha blocker or anticholinergic monotherapy. B3AR agonist therapy with phosphodiesterase 5 inhibitor (PDE5I) showed statistical improvement on urological symptom scores or QoL compared to PDE5I monotherapy. For safety profile, B3AR agonist in all 3 comparisons may not increase adverse event rate. While B3AR agonists may be used for the treatment of lower urinary tract symptoms in men with BPH if storage symptoms with standard BPH treatment are insufficient, B3AR agonists appear to have trivial or similar effects compared to current standard BPH treatment.

Deep learning-based automated quantification of the hepatorenal index for evaluation of fatty liver by ultrasonography

Purpose@#The aim of this study was to develop and validate a fully-automatic quantification of the hepatorenal index (HRI) calculated by a deep convolutional neural network (DCNN) comparable to the interpretations of radiologists experienced in ultrasound (US) imaging. @*Methods@#In this retrospective analysis, DCNN-based organ segmentation with Gaussian mixture modeling for automated quantification of the HRI was developed using abdominal US images from a previous study. For validation, 294 patients who underwent abdominal US examination before living-donor liver transplantation were selected. Interobserver agreement for the measured brightness of the liver and kidney and the calculated HRI were analyzed between two board-certified radiologists and DCNN using intraclass correlation coefficients (ICCs). @*Results@#Most patients had normal (n=95) or mild (n=198) fatty liver. The ICCs of hepatic and renal brightness measurements and the calculated HRI between the two radiologists were 0.892 (95% confidence interval [CI], 0.866 to 0.913), 0.898 (95% CI, 0.873 to 0.918), and 0.681 (95% CI, 0.615 to 0.738) for the first session and 0.920 (95% CI, 0.901 to 0.936), 0.874 (95% CI, 0.844 to 0.898), and 0.579 (95% CI, 0.497 to 0.650) for the second session, respectively; the results ranged from moderate to excellent agreement. Using the same task, the ICCs of the hepatic and renal measurements and the calculated HRI between the average values of the two radiologists and DCNN were 0.919 (95% CI, 0.899 to 0.935), 0.916 (95% CI, 0.895 to 0.932), and 0.734 (95% CI, 0.676 to 0.782), respectively, showing high to excellent agreement. @*Conclusion@#Automated quantification of HRI using DCNN can yield HRI measurements similar to those obtained by experienced radiologists in patients with normal or mild fatty liver.

The semi-erect position for better visualization of subphrenic hepatocellular carcinoma during ultrasonography examinations

Purpose@#This study investigated which body position is more useful for visualizing subphrenic hepatocellular carcinomas (HCCs) during ultrasonography (US) examinations. @*Methods@#This prospective study was approved by the institutional review board and written informed consent was obtained from all patients. Twenty consecutive patients with a single subphrenic HCC (treatment-naïve, 1 to 3 cm) underwent a US examination for planning radiofrequency ablation. The examinations were done by one of three radiologists and the patients were examined in four different body positions-supine, right posterior oblique (RPO), left lateral decubitus (LLD), and semi-erect-by being positioned on a tilted table. The visibility of the index tumor was prospectively assessed using a 4-point scale. Needle insertion was considered to be technically feasible if the visibility score was lower than 2. The visibility score and technical feasibility were compared using the Wilcoxon signed rank test and the McNemar test, respectively, for pairwise comparisons between different body positions. @*Results@#The visibility score was significantly lower in the semi-erect position (median, 2; interquartile range, 1 to 2.75) than in the supine (3, 2 to 4), RPO (3, 2 to 4), and LLD (4, 3.25 to 4) positions (P=0.007, P=0.005, and P=0.001, respectively). The technical feasibility of needle insertion was also significantly higher in the semi-erect position (75%, 15/20) than in the supine (45%, 9/45), RPO (35%, 7/20), and LLD (20%, 4/20) positions (P=0.031, P=0.021, and P=0.001, respectively). @*Conclusion@#The semi-erect position is more useful for the visualization of subphrenic HCCs than the supine, RPO, or LLD positions.

Effect of Perfluorobutane Microbubbles onRadiofrequency Ablation for Hepatocellular Carcinoma:Suppression of Steam Popping and Its ClinicalImplication

Objective@#To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on steam popping duringradiofrequency (RF) ablation for treating hepatocellular carcinoma (HCC), and to assess whether popping affects treatmentoutcomes. @*Materials and Methods@#The institutional review board approved this retrospective study, which included 90 consecutivepatients with single HCC, who received percutaneous RF ablation as the first-line treatment. The patients were divided intotwo groups, based on the presence or absence of the popping phenomenon, which was defined as an audible sound with asimultaneous sudden explosion within the ablation zone as detected via ultrasonography during the procedure. The factorscontributing to the popping phenomenon were identified using multivariable logistic regression analysis. Local tumor progression(LTP) and disease-free survival (DFS) were assessed using the Kaplan-Meier method with the log-rank test for performingcomparisons between the two groups. @*Results@#The overall incidence of the popping phenomenon was 25.8% (24/93). Sonazoid® was used in 1 patient (4.2%) inthe popping group (n = 24), while it was used in 15 patients (21.7%) in the non-popping group (n = 69). Multivariableanalysis revealed that the use of Sonazoid® was the only significant factor for absence of the popping phenomenon (oddsratio = 0.10, p= 0.048). There were no significant differences in cumulative LTP and DFS between the two groups (p= 0.479and p= 0.424, respectively). @*Conclusion@#The use of Sonazoid® has a suppressive effect on the popping phenomenon during RF ablation in patients withHCC. However, the presence of the popping phenomenon may not affect clinical outcomes.

Comparison of outcome between liver resection, radiofrequency ablation, and transarterial therapy for multiple small hepatocellular carcinoma within the Milan criteria

Purpose@#Although surgical resection is usually considered for a single tumor, several reports have suggested that resection can be considered for multiple tumors. The objective of this study was to determine whether resection could provide better long-term outcome for patients with multiple hepatocellular carcinomas (HCCs) within Milan criteria. @*Methods@#A total of 276 patients with multiple HCCs within Milan criteria with liver function preserved who underwent resection, radiofrequency ablation (RFA), or transarterial chemoembolization (TACE) between 2009 and 2013 were analyzed. Propensity-score (PS) matching was conducted. @*Results@#Five-year overall survival (OS) and recurrence-free survival (RFS) were better in the resection group than that in the RFA or TACE group. Patients who underwent resection had more preserved liver function and different tumor characteristics compared to those received RFA or TACE. With similar baseline characteristics generated in the PS model, there was no difference in 5-year OS among 3 groups (79.5% vs. 72.3% or 62.0%, P = 0.232), but the 5-year RFS was better for patients who received resection than those who received RFA or TACE (51.9% vs. 22.0% or 0.0%, P < 0.001). Although the major complication rate was slightly higher than RFA or TACE, there was no significant difference between the 3 groups before and after PS matching. @*Conclusion@#Resection was associated with better RFS than RFA or TACE and showed comparable OS in multiple HCC patients within the Milan criteria, but at a cost of slightly increased risk of complication. Resection can be considered as a first-line option if selected appropriately.

Potential Utility of Prostate Health Index Density for Prostate Cancer Detection and Prediction in Korean Men: A Prospective Multicenter Study

Purpose@#We evaluated the clinical performance of Prostate Health Index (PHI) density with [-2]proPSA (p2PSA)and its derivatives in predicting the presence of prostate cancer (PCa) in Korean men. @*Materials and Methods@#A total of 706 men with total prostate-specific antigen (tPSA)≥2.5 ng/mL who underwenttheir first prostate biopsy were included in this prospective, multicenter, observational study. Diagnostic accuracyof tPSA, free-to-total PSA ratio (%fPSA), p2PSA, %p2PSA, the Beckman Coulter PHI, and PHI density wasassessed by receiver operating characteristic curve analyses and logistic regression analyses. PHI was calculatedas [(p2PSA/free PSA)×tPSA½], and density calculations were performed using prostate volume as determinedby transrectal ultrasonography. @*Results@#Overall, PCa was detected in 367 of all subjects (52%). In men with tPSA 2.5–10 ng/mL, the detectionrate of PCa was 41.1% (188 of 457). In this group, PHI and PHI density were the most accurate predictorsof PCa and significantly outperformed tPSA and %fPSA; area under the curve for tPSA, %fPSA, %p2PSA, PHI,and PHI density was 0.58, 0.68, 0.70, 0.75, 0.73 respectively. PHI and PHI density were also the strongestpredictor of PCa with Gleason score ≥7. @*Conclusions@#Based on the present prospective multicenter experience, PHI and PHI density demonstrate thesuperior clinical performance in predicting the presence of PCa in Korean men with tPSA 2.5–10 ng/mL.

Primary Leiomyosarcoma in Bladder

Leiomyosarcoma of the bladder is a very rare tumor and it has been reported in less than 200 cases in the literature which represent 0.1% of all nonurothelial bladder tumors. We experienced a case of sarcoma of bladder that protruding into the urinary bladder in 51-year-old woman. She underwent mass excision with enucleation for the bladder function preservation. Pathologically, the mass consisted of high grade leiomyosarcoma. In immunohistochemical study, tumor showed positive reactions for smooth muscle actin and desmin. After mass excision, follow-up radiation treatment is ongoing. Herein, we present the case of a high-grade leiomyosarcoma with literature review.

Usefulness of Virtual Expiratory CT Images to Compensate for Respiratory Liver Motion in Ultrasound/CT Image Fusion: A Prospective Study in Patients with Focal Hepatic Lesions

OBJECTIVE: To assess whether virtual expiratory (VE)-computed tomography (CT)/ultrasound (US) fusion imaging is more effective than conventional inspiratory (CI)-CT/US fusion imaging for hepatic interventional procedures. MATERIALS AND METHODS: This prospective study was approved by the Institutional Review Board, and informed consent was obtained from each patient. In total, 62 patients with focal hepatic lesions referred for hepatic interventional procedures were enrolled. VE-CT images were generated from CI-CT images to reduce the effects of respiration-induced liver motion. The two types of CT images were fused with real-time US images for each patient. The operators scored the visual similarity with the liver anatomy upon initial image fusion and the summative usability of complete image fusion using the respective five-point scales. The time required for complete image fusion and the number of point locks used were also compared. RESULTS: In comparison with CI-CT/US fusion imaging, VE-CT/US fusion imaging showed significantly higher visual similarity with the liver anatomy on the initial image fusion (mean score, 3.9 vs. 1.7; p < 0.001) and higher summative usability for complete image fusion (mean score, 4.0 vs. 1.9; p < 0.001). The required time (mean, 11.1 seconds vs. 22.5 seconds; p < 0.001) and the number of point locks (mean, 1.6 vs. 3.0; p < 0.001) needed for complete image fusion using VE-CT/US fusion imaging were significantly lower than those needed for CI-CT/US fusion imaging. CONCLUSION: VE-CT/US fusion imaging is more effective than CI-CT/US fusion imaging for hepatic interventional procedures.

Identification of Arterial Hyperenhancement in CT and MRI in Patients with Hepatocellular Carcinoma: Value of Unenhanced Images

OBJECTIVE: According to the current guidelines, arterial hyperenhancement for diagnosis of hepatocellular carcinoma (HCC) is determined using the arterial phase only. We investigated the optimal definition of arterial hyperenhancement in patients with HCC using computed tomography (CT) and magnetic resonance imaging (MRI). MATERIALS AND METHODS: The Institutional Review Board approved this retrospective study. The requirement for informed consent was waived. Between January 2011 and September 2013, 147 consecutive patients with surgically proven HCCs with both pre-operative CT and MRI were included. Identification rates of arterial hyperenhancement on CT and magnetic resonance (MR) images using arterial phase only, dual phase (unenhanced and arterial phases), and also subtraction MR images were assessed qualitatively. RESULTS: The identification rates for arterial hyperenhancement on CT were significantly different between arterial phase and dual phase (72.8% vs. 90.5%; p < 0.001), whereas the rates were similar on MRI (91.8% vs. 93.9%; p = 0.257). The identification rate of arterial hyperenhancement in MRI increased to 98.6% using subtraction MR images. CONCLUSION: Visual comparison of arterial and unenhanced phases could be recommended instead of conventional qualitative arterial phase alone assessment to determine arterial hyperenhancement of HCCs, especially when using CT.

Active contour configuration model for estimating the posterior ablative margin in image fusion of real-time ultrasound and 3D ultrasound or magnetic resonance images for radiofrequency ablation: an experimental study

PURPOSE: The purpose of this study was to evaluate the accuracy of an active contour model for estimating the posterior ablative margin in images obtained by the fusion of real-time ultrasonography (US) and 3-dimensional (3D) US or magnetic resonance (MR) images of an experimental tumor model for radiofrequency ablation. METHODS: Chickpeas (n=12) and bovine rump meat (n=12) were used as an experimental tumor model. Grayscale 3D US and T1-weighted MR images were pre-acquired for use as reference datasets. US and MR/3D US fusion was performed for one group (n=4), and US and 3D US fusion only (n=8) was performed for the other group. Half of the models in each group were completely ablated, while the other half were incompletely ablated. Hyperechoic ablation areas were extracted using an active contour model from real-time US images, and the posterior margin of the ablation zone was estimated from the anterior margin. After the experiments, the ablated pieces of bovine rump meat were cut along the electrode path and the cut planes were photographed. The US images with the estimated posterior margin were compared with the photographs and post-ablation MR images. The extracted contours of the ablation zones from 12 US fusion videos and post-ablation MR images were also matched. RESULTS: In the four models fused under real-time US with MR/3D US, compression from the transducer and the insertion of an electrode resulted in misregistration between the real-time US and MR images, making the estimation of the ablation zones less accurate than was achieved through fusion between real-time US and 3D US. Eight of the 12 post-ablation 3D US images were graded as good when compared with the sectioned specimens, and 10 of the 12 were graded as good in a comparison with nicotinamide adenine dinucleotide staining and histopathologic results. CONCLUSION: Estimating the posterior ablative margin using an active contour model is a feasible way of predicting the ablation area, and US/3D US fusion was more accurate than US/MR fusion.

Diagnostic Performance of %-2proPSA and Prostate Health Index for Prostate Cancer: Prospective, Multi-institutional Study

BACKGROUND: We evaluated the clinical performance of [-2]proPSA (p2PSA) and its derivatives in predicting the presence and aggressiveness of prostate cancer (PCa) in Korean men. METHODS: A total of 246 men with total prostate-specific antigen (tPSA) ≥ 3.5 ng/mL who underwent their first prostate biopsy were included in this prospective, multicenter, observational study. Diagnostic accuracy of tPSA, free-to-total PSA ratio (%fPSA), p2PSA, %p2PSA, and the Beckman Coulter prostate health index (PHI) was assessed by receiver operating characteristic curve analyses and logistic regression analyses. RESULTS: Overall, PCa was detected in 125 (50.8%) subjects. In men with tPSA 3.5–10 ng/mL, the detection rate of PCa was 39.4% (61/155). In this group, PHI and %p2PSA were the most accurate predictors of PCa and significantly outperformed tPSA and %fPSA; area under the curve for tPSA, %fPSA, %p2PSA, and PHI was 0.56, 0.69, 0.74, and 0.76, respectively. PHI was also the strongest predictor of PCa with Gleason score ≥ 7. CONCLUSION: This study demonstrates the superior clinical performance of %p2PSA and PHI in predicting the presence and aggressiveness of PCa in Korean men. The %p2PSA and PHI appear to improve detection of PCa and provide prognostic information.

The Usefulness of Minimally Invasive Plate Osteosynthesis to Manage Comminuted Mid-Clavicle Fracture: A Comparison with Conventional Open Plating / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to compare the clinical and radiological outcomes of minimally invasive plate osteosynthesis (MIPO) with those of conventional open plating (COP) for treating comminuted mid-clavicular fractures and to evaluate the usefulness of MIPO. MATERIALS AND METHODS: Thirty-nine patients who underwent surgical treatment for mid-clavicular comminuted fractures were analyzed retrospectively. Nineteen patients were treated with MIPO and twenty patients with COP. Radiological evaluation included time to union, fracture healing, and clavicular length difference measured as the proportional length difference with the unaffected side. Clinical assessment was performed using the simple shoulder test score, American Shoulder and Elbow Surgeons score, and quick disability of the arm, shoulder and hand score. Moreover, the mean operation and radiation times, as well as exposure were compared. RESULTS: All clavicles achieved bone union. The mean time to union was 12.1 weeks in the MIPO group, and 14.6 weeks in the COP group (p=0.587). There was no significant difference between the two groups regarding the functional and radiological outcomes at 2-year follow-up. A significantly shorter operation time was observed in the MIPO group than in the COP group (75.8 min vs. 106.9 min, p=0.002). More radiation time and exposure were identified in the MIPO group (52.8 s vs. 37.1 s, p=0.002; 209.4 mGy vs. 43.1 mGy, p=0.005). CONCLUSION: Both COP and MIPO were shown to be effective treatment options for mid-clavicular comminuted fractures. MIPO may be a better alternative to COP due to shorter operation time and no need for a bone graft, although the functional and radiological outcomes were not significantly different. However, all surgeons should pay close attention to minimize radiation hazard.