Re-assessing the diagnostic value of the enhancing "capsule" in hepatocellular carcinoma imaging.

Background/Aims: The enhancing "capsule" (EC) in hepatocellular carcinoma (HCC) diagnosis has received varying degrees of recognition across major guidelines. This study aimed to assess the diagnostic utility of EC in HCC detection. Methods: We retrospectively analyzed patients who underwent pre-surgical computed tomography (CT) and hepatobiliary agent-enhanced magnetic resonance imaging (HBA-MRI) between January 2016 and December 2019. A single hepatic tumor was confirmed based on the pathology of each patient. Three radiologists independently reviewed the images according to the Liver Imaging Reporting and Data System (LIRADS) v2018 criteria and reached a consensus. Interobserver agreement for EC before reaching a consensus was quantified using Fleiss κ statistics. The impact of EC on the LI-RADS classification was assessed by comparing the positive predictive values for HCC detection in the presence and absence of EC. Results: In total, 237 patients (median age, 60 years; 184 men) with 237 observations were included. The interobserver agreement for EC detection was notably low for CT (κ=0.169) and HBA-MRI (κ=0.138). The presence of EC did not significantly alter the positive predictive value for HCC detection in LI-RADS category 5 observations on CT (94.1% [80/85] vs. 94.6% [88/93], P=0.886) or HBA-MRI (95.7% [88/92] vs. 90.6% [77/85], P=0.178). Conclusions: The diagnostic value of EC in HCC diagnosis remains questionable, given its poor interobserver agreement and negligible impact on positive predictive values for HCC detection. This study challenges the emphasis on EC in certain diagnostic guidelines and suggests the need to re-evaluate its role in HCC imaging.

Important Radiologic and Clinical Factors for Predicting Overall Survival in Pancreatic Adenocarcinoma Patients Who Underwent FOLFIRINOX.

BACKGROUND: To predict poor overall survival (OS) in pancreatic adenocarcinoma (PAC) who underwent FOLFIRINOX (5-fluorouracil/leucovorin/irinotecan/oxaliplatin) using clinical and computed tomography (CT) findings. METHODS: A total of 189 patients with PAC who received FOLFIRINOX were retrospectively included. Two reviewers assessed CT findings and resectability based on National Comprehensive Cancer Network guidelines. They determined tumor size changes according to Response Evaluation Criteria in Solid Tumors (RECIST 1.1). Delta measurements were performed. Clinical results, such as whether to perform surgery, were also investigated. A Cox proportional hazard model was used to identify significant predictors for OS. A CT-based nomogram was constructed to predict OS. RESULTS: Seventy-four patients (39.2%) underwent surgery. For OS, rim enhancement of PAC on baseline CT (hazard ratio [HR], 1.75; 95% confidence interval [CI], 1.10-2.77; P = 0.018), high delta tumor on baseline CT (HR, 2.46; 95% CI, 1.55-3.91; P < 0.001), progressive disease at follow-up CT (HR, 8.89; 95% CI, 2.94-26.87; P < 0.001), and without surgery (HR, 2.81; 95% CI, 1.49-5.30; P = 0.001) were important features related to poor prognosis. The nomogram showed good predictive ability for the survival. CONCLUSION: Both clinical and CT findings were useful for predicting OS after FOLFIRINOX in PAC.

Pancreas CT assessment for pancreatic ductal adenocarcinoma resectability: effect of tube voltage and slice thickness on image quality and diagnostic performance.

OBJECTIVES: To assess the resectability of pancreatic ductal adenocarcinoma (PDAC), the evaluation of tumor vascular contact holds paramount significance. This study aimed to compare the image quality and diagnostic performance of high-resolution (HR) pancreas computed tomography (CT) using an 80 kVp tube voltage and a thin slice (1 mm) for assessing PDAC resectability, in comparison with the standard protocol CT using 120 kVp. METHODS: This research constitutes a secondary analysis originating from a multicenter prospective study. All participants underwent both the standard protocol pancreas CT using 120 kVp with 3 mm slice thickness (ST) and HR-CT utilizing an 80 kVp tube voltage and 1 mm ST. The contrast-to-noise ratio (CNR) between parenchyma and tumor, along with the degree of enhancement of the abdominal aorta and main portal vein (MPV), were measured and subsequently compared. Additionally, the likelihood of margin-negative resection (R0) was evaluated using a five-point scale. The diagnostic performance of both CT protocols in predicting R0 resection was assessed through the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 69 patients (37 males and 32 females; median age, 66.5 years) were included in the study. The median CNR of PDAC was 10.4 in HR-CT, which was significantly higher than the 7.1 in the standard CT (P=0.006). Furthermore, HR-CT demonstrated notably higher median attenuation values for both the abdominal aorta (579.5 HU vs. 327.2 HU; P=0.002) and the MPV (263.0 HU vs. 175.6 HU; P=0.004) in comparison with standard CT. Following surgery, R0 resection was achieved in 51 patients. The pooled AUC for HR-CT in predicting R0 resection was 0.727, slightly exceeding the 0.699 of standard CT, albeit lacking a significant statistical distinction (P=0.128). CONCLUSION: While HR pancreas CT using 80 kVp offered a notably greater degree of contrast enhancement in vessels and a higher CNR for PDAC compared to standard CT, its diagnostic performance in predicting R0 resection remained statistically comparable.

Newly developed sarcopenia after liver transplantation, determined by a fully automated 3D muscle volume estimation on abdominal CT, can predict post-transplant diabetes mellitus and poor survival outcomes.

BACKGROUND: Loss of muscle mass is the most common complication of end-stage liver disease and negatively affects outcomes for liver transplantation (LT) recipients. We aimed to determine the prognostic value of a fully automated three-dimensional (3D) muscle volume estimation using deep learning algorithms on abdominal CT in patients who underwent liver transplantation (LT). METHODS: This retrospective study included 107 patients who underwent LT from 2014 to 2015. Serial CT scans, including pre-LT and 1- and 2-year follow-ups were performed. From the CT scans, deep learning-based automated body composition segmentation software was used to calculate muscle volumes in 3D. Sarcopenia was calculated by dividing average skeletal muscle area by height squared. Newly developed-(ND) sarcopenia was defined as the onset of sarcopenia 1 or 2 years after LT in patients without a history of sarcopenia before LT. Patients' clinical characteristics, including post-transplant diabetes mellitus (PTDM) and Model for end-stage liver disease score, were compared according to the presence or absence of sarcopenia after LT. A subgroup analysis was performed in the post-LT sarcopenic group. The Kaplan-Meier method was used for overall survival (OS). RESULTS: Patients with ND-sarcopenia had poorer OS than those who did not (P = 0.04, hazard ratio [HR], 3.34; 95% confidence interval [CI] 1.05 - 10.7). In the subgroup analysis for post-LT sarcopenia (n = 94), 34 patients (36.2%) had ND-sarcopenia. Patients with ND-sarcopenia had significantly worse OS (P = 0.002, HR 7.12; 95% CI 2.00 - 25.32) and higher PTDM occurrence rates (P = 0.02, HR 4.93; 95% CI 1.18 - 20.54) than those with sarcopenia prior to LT. CONCLUSION: ND-sarcopenia determined by muscle volume on abdominal CT can predict poor survival outcomes and the occurrence of PTDM for LT recipients.

Clinical feasibility of radiofrequency ablation using novel adjustable separable electrodes with a multipurpose needle for treating small hepatocellular carcinomas: a prospective single center study.

BACKGROUND: The novel separable clustered electrode system with two adjustable active tips (ICAEs) and a fine multipurpose needle (MPN) for in situ temperature monitoring and adjuvant agent injection was developed and validated in an animal study. The purpose of this study was to evaluate the technical efficacy and complication of the novel electrode system for patients who have small HCC. METHODS: In this prospective, single-center clinical trial, ten participants with 14 small (≤ 2 cm, BCLC 0-A) HCCs referred for RFA were enrolled. A novel electrode system consisting of two ICAEs and one MPN with a thermometer and side holes was used for RFA. The RF energy was delivered using a multichannel RF system combining bipolar and switching monopolar modes. Technical success, efficacy, and complications were evaluated on immediate and one-month follow-up CT. RESULTS: Technical success was achieved in 92.9% (13/14) of tumors. One participant withdrew consent after RFA, and technical efficacy was achieved in 91.7% (11/12) of tumors. None showed thermal injury to nontarget organs. All patients were discharged the day after RFA without major complications. The active electrode lengths were adjusted in 60% (6/10) of patients during the procedure to tailor the ablation zone (83.3%, n = 5) or treat two tumors with different sizes (16.7%, n = 1). MPN was capable of continuous temperature monitoring during all ablations (100%, 14/14). CONCLUSIONS: RFA using a novel electrode system showed acceptable technical efficacy and safety in patients with small HCCs. Further comparative studies are needed for the investigation of the system's potential benefits compared to conventional electrodes.

Abbreviated MRI for Secondary Surveillance of Recurrent Hepatocellular Carcinoma After Presumed Curative Treatment.

BACKGROUND: Little is known about the performance of abbreviated MRI (AMRI) for secondary surveillance of recurrent hepatocellular carcinoma (HCC) after curative treatment. PURPOSE: To evaluate the detection performance of AMRI for secondary surveillance of HCC after curative treatment. STUDY TYPE: Retrospective. POPULATION: A total of 243 patients (183 men and 60 women; median age, 65 years) who underwent secondary surveillance for HCC using gadoxetic acid-enhanced MRI after more than 2 year of disease-free period following curative treatment, including surgical resection or radiofrequency ablation (RFA). FIELD STRENGTH/SEQUENCE: A 3.0 T/noncontrast AMRI (NC-AMRI) (T2-weighted fast spin-echo, T1-weighted gradient echo, and diffusion-weighted images), hepatobiliary phase AMRI (HBP-AMRI) (T2-weighted fast spin-echo, diffusion-weighted, and HBP images), and full-sequence MRI ASSESSMENT: Four board-certified radiologists independently reviewed NC-AMRI, HBP-AMRI, and full-sequence MRI sets of each patient for detecting recurrent HCC. STATISTICAL TESTS: Per-lesion sensitivity, per-patient sensitivity and specificity for HCC detection at each set were compared using generalized estimating equation. RESULTS: A total of 42 recurred HCCs were confirmed in the 39 patients. The per-lesion and per-patient sensitivities did not show significant differences among the three image sets for either reviewer (P ≥ 0.358): per-lesion sensitivity: 59.5%-83.3%, 59.5%-85.7%, and 59.5%-83.3%, and per-patient sensitivity: 53.9%-83.3%, 56.4%-85.7%, and 53.9%-83.3% for NC-AMRI, HBP-AMRI, and full-sequence MRI, respectively. Per-lesion pooled sensitivities of NC-AMRI, HBP-AMRI, and full-sequence MRI were 72.6%, 73.2%, and 73.2%, with difference of -0.6% (95% confidence interval: -6.7, 5.5) between NC-AMRI and full-sequence MRI and 0.0% (-6.1, 6.1) between HBP-AMRI and full-sequence MRI. Per-patient specificity was not significantly different among the three image sets for both reviewers (95.6%-97.1%, 95.6%-97.1%, and 97.6%-98.5% for NC-AMRI and HBP-AMRI, respectively; P ≥ 0.117). DATA CONCLUSION: NC-AMRI and HBP-AMRI showed no significant difference in detection performance to that of full-sequence gadoxetic acid-enhanced MRI during secondary surveillance for HCC after more than 2-year disease free interval following curative treatment. Based on its good detection performance, short scan time, and lack of contrast agent-associated risks, NC-AMRI is a promising option for the secondary surveillance of HCC. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 2.

Can "no-touch" radiofrequency ablation for hepatocellular carcinoma improve local tumor control? Systematic review and meta-analysis.

OBJECTIVES: Percutaneous radiofrequency ablation (RFA) is one of the curative treatments for hepatocellular carcinoma (HCC), but local tumor progression (LTP) has been a main limitation of RFA. This study aims to evaluate the LTP of percutaneous no-touch RFA (NtRFA) for HCC ≤ 5 cm and compare with conventional RFA (intratumoral puncture) through a systematic review and meta-analysis. METHODS: MEDLINE, EMBASE, and Cochrane Library were searched for studies on percutaneous NtRFA for HCC ≤ 5 cm. The pooled proportions of the overall and cumulative incidence rates at 1, 2, and 3 years for LTP after NtRFA were assessed using a random-effects model. For studies comparing NtRFA with conventional RFA, relative risks (RR) and hazard ratios (HR) were meta-analytically pooled with LTP as the outcome. RESULTS: Twelve studies with 900 patients were included. The pooled overall rate of LTP after NtRFA was 6% (95% CI, 4-8%). The pooled 1-, 2-, and 3-year cumulative incidence rates of LTP were 3% (95% CI, 2-5%), 5% (95% CI, 3- 9%), and 8% (95% CI, 6-11%), respectively. Compared to conventional RFA, the pooled RR and HR of LTP were 0.26 (95% CI, 0.16-0.41) and 0.28 (95% CI, 0.11-0.70), respectively (both p < 0.01). Subgroup analysis including only randomized controlled studies also showed better local tumor control of NtRFA with HR of 0.13 (95% CI, 0.14-0.42). CONCLUSIONS: Percutaneous NtRFA is an effective treatment for HCC ≤ 5 cm with an overall LTP rate of 6% and provides lower LTP compared with conventional RFA. KEY POINTS: • The pooled 1-, 2-, and 3-year cumulative incidence rates of local tumor progression after no-touch radiofrequency ablation for HCC ≤ 5 cm were 3% (95% CI, 2-5%), 5% (95% CI, 3-9%), and 8% (95% CI, 6-11%). • No-touch radiofrequency ablation had significantly lower rates of local tumor progression compared to conventional radiofrequency ablation (hazard ratio, 0.28; 95% CI, 0.11-0.70; relative risk, 0.26; 95% CI, 0.16-0.41; p < 0.01, respectively).

Colon cancer CT staging according to mismatch repair status: Comparison and suggestion of imaging features for high-risk colon cancer.

BACKGROUND: Neoadjuvant treatment with either chemotherapy or immunotherapy is gaining momentum in colon cancers (CC). To reduce over-treatment, increasing staging accuracy using computed tomography (CT) is of high importance. PURPOSE: To assess and compare CT imaging features of CC between mismatch repair-proficient (pMMR) and MMR-deficient (dMMR) tumours and identify CT features that can distinguish high-risk (pT3-4, N+) CC according to MMR status. METHODS: Primary staging CTs of 266 patients who underwent primary surgical resection of a colon tumour were retrospectively and independently evaluated by two radiologists. Logistic regression analysis was performed to identify significant associations between imaging features and positive lymph node status. Receiver operating characteristic (ROC) curves of significantly associated features were assessed and validated in an external cohort of 104 patients. RESULTS: Among pT3 tumours only, dMMR CC were significantly larger than pMMR CC in both length and thickness (length 59.39 ± 26.28 mm versus 48.70 ± 23.72, respectively, p = 0.031; thickness 20.54 mm ± 11.17 versus 16.34 ± 8.73, respectively, p = 0.027). For pMMR tumours, nodal internal heterogeneity on CT was significantly associated with a positive lymph node status (odds ratio (OR) = 2.66, p = 0.027), while for dMMR tumours, the largest short diameter of the nodes was associated with lymph node status (OR = 2.01, p = 0.049). The best cut-off value of the largest short diameter of involved nodes was 10.4 mm for dMMR and 7.95 mm for pMMR. In the external validation cohort, AUCs for predicting involved nodes based on the largest short diameter was 0.764 for dMMR tumours using 10 mm size cut-off and 0.624 for pMMR tumours using 7 mm cut-off. CONCLUSION: These data show that CT imaging features of primary CC differ between dMMR and pMMR tumours, suggesting that the assessment of CT-based CC staging should take MMR status into consideration, especially for lymph node status, and thus may help in selecting patients for neoadjuvant treatment.

Identifying high-risk colon cancer on CT an a radiomics signature improve radiologist's performance for T staging?

PURPOSE: To assess the role of radiomics in detection of high-risk (pT3-4) colon cancer and develop a combined model that combines both radiomics and CT staging of colon cancer. METHODS: We included 292 colon cancer patients who underwent pre-operative CT and primary surgical resection within 2 months. Three-dimensional segmentations and CT staging of primary colon tumors were done. From each 3D segmentation of colon tumor, radiomic features were automatically extracted. Logistic regression analysis was performed to identify associations between radiomic features and high-risk (pT3-4) colon tumors. A combined model that integrated both radiomics and CT staging was developed and their diagnostic performance was compared with that of conventional CT staging. Tenfold cross-validation was used to validate the performance of the model and CT staging. RESULTS: The model that combined radiomic features and CT staging demonstrated a significantly better performance in detection of high-risk colon tumors in training set (AUC = 0.799, 95% CI: 0.720-0.839 for combined model and AUC = 0.697, 95% CI = 0.538-0.756 for CT staging only, p < 0.001 for difference). Cross-validation results also demonstrated significantly better detection performance of combined model (AUC = 0.727, 95% Confidence Interval (CI): 0.621-0.777 for combined model and AUC = 0.628, 95% CI = 0.558-0.689 for CT staging only, Boot CI = 0.099). CONCLUSION: CT radiomic features of primary colon cancer, combined with CT staging, can improve the detection of high-risk colon cancer patients.

LI-RADS Version 2018 Targetoid Appearances on Gadoxetic Acid-Enhanced MRI: Interobserver Agreement and Diagnostic Performance for the Differentiation of HCC and Non-HCC Malignancy.

BACKGROUND. In LI-RADS version 2018, observations showing at least one of five targetoid appearances in different sequences or postcontrast phases are categorized LR-M, indicating likely non-hepatocellular carcinoma (HCC) malignancy. OBJECTIVE. The purpose of this study was to evaluate interobserver agreement for LI-RADS targetoid appearances among a large number of radiologists of varying experience and the diagnostic performance of targetoid appearances for differentiating HCC from non-HCC malignancy. METHODS. This retrospective study included 100 patients (76 men, 24 women; mean age, 58 ± 9 [SD] years) at high risk of HCC who underwent gadoxetic acid-enhanced MRI within 30 days before hepatic tumor resection (25 randomly included patients with non-HCC malignancy [13, intrahepatic cholangiocarcinoma; 12, combined HCC-cholangiocarcinoma]; 75 matched patients with HCC). Eight radiologists (four more experienced [8-15 years]; four less experienced [1-5 years]) from seven institutions independently assessed observations for the five targetoid appearances and LI-RADS categorization. Interobserver agreement and diagnostic performance for non-HCC malignancy were evaluated. RESULTS. Interobserver agreement was poor for peripheral washout (κ = 0.20); moderate for targetoid transitional phase or hepatobiliary phase appearance (κ = 0.33), delayed central enhancement (κ = 0.37), and targetoid restriction (κ = 0.43); and substantial for rim arterial phase hyperenhancement (κ = 0.61). Agreement was fair for at least one targetoid appearance (κ = 0.36) and moderate for at least two, three, or four targetoid appearances (κ = 0.43-0.51). Agreement for individual targetoid appearances was not significantly different between more experienced and less experienced readers other than for targetoid restriction (κ = 0.63 vs 0.43; p = .001). Agreement for at least one targetoid appearance was fair among more experienced (κ = 0.29) and less experienced (κ = 0.37) reviewers. Agreement for at least two, three, or four targetoid appearances was moderate to substantial among more experienced reviewers (κ = 0.45-0.63) and moderate among less experienced reviewers (κ = 0.42-0.56). Existing LR-M criteria of at least one targetoid appearance had median accuracy for non-HCC malignancy of 62%, sensitivity of 84%, and specificity of 54%. For all reviewers, accuracy was highest when at least three (median accuracy, 79%; sensitivity, 68%; specificity, 82%) or four (median accuracy, 80%; sensitivity, 54%; specificity, 88%) targetoid appearances were required. CONCLUSION. Targetoid appearances and LR-M categorization exhibited considerable interobserver variation among both more and less experienced reviewers. CLINICAL IMPACT. Requiring multiple targetoid appearances for LR-M categorization improved interobserver agreement and diagnostic accuracy for non-HCC malignancy.

LI-RADS Tumor in Vein at CT and Hepatobiliary MRI.

Background Diagnostic performance of the Liver Imaging Reporting and Data System tumor in vein (LR-TIV) category at CT and/or MRI has not yet been evaluated, to the knowledge of the authors. Purpose To assess the diagnostic performance of the LR-TIV category in detecting macroscopic tumors in veins (TIVs) at CT and hepatobiliary contrast agent-enhanced (HBA) MRI, with pathologic results used as the reference standard. Materials and Methods Between January 2010 and December 2019, consecutive patients with or without macroscopic TIV who underwent both CT and HBA MRI before hepatic resection or liver transplant were retrospectively included. Three radiologists independently assessed the LR-TIV features of enhancing soft tissue in vein and features suggestive of TIV (FSTIV) and reached a consensus. Macroscopic TIV at pathologic examination was the reference standard. Sensitivities and specificities of the LR-TIV category without and with FSTIV were calculated, and the added value of FSTIV was evaluated by using the McNemar test. Results In the 1322 patients with (n = 101) or without (n = 1221) macroscopic TIV (median age, 64 years [interquartile range, 58-70 years]; 1053 men), without consideration of FSTIV, the sensitivity and specificity of enhancing soft tissue in vein for detecting macroscopic TIV at pathologic examination were 64.4% (65 of 101) and 99.8% (1218 of 1221) with CT and 62.4% (63 of 101) and 99.8% (1218 of 1221) with HBA MRI, respectively. With consideration of FSTIV, the sensitivity and specificity of the LR-TIV category became 67.3% (68 of 101 patients) and 99.7% (1217 of 1221 patients) at both CT and HBA MRI. No difference was found between measurements without and with FSTIV (sensitivity, 62% vs 67% for CT [P = .45] and 64% vs 67% for HBA MRI [P = .18]; specificity, 99% for both CT and HBA MRI [P > .99 for both]). Conclusion The Liver Imaging Reporting and Data System tumor in vein category showed moderate sensitivity and high specificity in the detection of macroscopic tumors in veins at both CT and hepatobiliary contrast agent-enhanced MRI, with pathologic examination used as the reference standard. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Morrell in this issue.

LI-RADS v2018: how to appropriately use ancillary features in category adjustment from intermediate probability of malignancy (LR-3) to probably HCC (LR-4) on gadoxetic acid-enhanced MRI.

OBJECTIVES: To determine the appropriate use of ancillary features (AFs) in upgrading LI-RADS category 3 (LR-3) to category 4 (LR-4) for hepatic nodules on gadoxetic acid-enhanced MRI. METHODS: We retrospectively analyzed MRI features of solid hepatic nodules (≤ 30 mm) categorized as LR-3/4 on gadoxetic acid-enhanced MRI. In LI-RADS diagnostic table-based-LR-3 observations, logistic regression analyses were performed to identify AFs suggestive of hepatocellular carcinomas (HCCs) rather than non-malignant nodules. Using McNemar's test, the sensitivities and specificities of the final-LR-4 category for HCC diagnosis were compared according to the principles of AF application in category adjustment. RESULTS: A total of 336 hepatic nodules (191 HCCs; 145 non-malignant) in 252 patients were evaluated. Based on major HCC features, 248 nodules (123 HCCs) were assigned as table-based-LR-3 and 88 nodules (68 HCCs) as table-based-LR-4. In table-based-LR-3 observations, mild-moderate T2 hyperintensity was identified as an independent predictor of HCC as opposed to non-malignant nodules (odds ratio = 3.01, p = 0.002). For HCC diagnosis, different criteria of final-LR-4: only table-based-LR-4, allowing category upgrade using only T2 hyperintensity, or using any AFs favoring malignancy resulted in sensitivities of 35.6% (68/191), 53.9% (103/191), and 88.5% (169/191), and specificities of 86.2% (125/145), 75.9% (110/145), and 21.4% (31/145), respectively, which differed from each other (all p < 0.001). CONCLUSIONS: While the application of MRI AF in LI-RADS category adjustment increases the sensitivity of LR-4 category for HCC diagnosis, it is accompanied by a significant decrease in specificity. Mild-moderate T2 hyperintensity, a significant AF indicative of HCC, may be more appropriate for upgrading LR-3 to LR-4. KEY POINTS: • When upgrading from LR-3 to LR-4 using any MRI ancillary features favoring malignancy, LR-4 sensitivity increases but specificity decreased for HCC diagnosis. • By upgrading LR-3 to LR-4 based on MRI ancillary features found to suggest HCC rather than non-malignant nodules in multivariate analysis (i.e., mild-moderate T2 hyperintensity), LR-4 demonstrated a more balanced sensitivity and specificity for HCC diagnosis (53.9% and 75.9%, respectively).

Predictors of conversion surgery in patients with pancreatic cancer who underwent neoadjuvant or palliative FOLFIRINOX treatment using baseline and follow-up CT.

PURPOSE: We aimed to evaluate the predictive factors of conversion surgery in pancreatic adenocarcinoma (PAC) after neoadjuvant or palliative FOLFIRINOX using baseline and follow-up CT. METHODS: We retrospectively included 189 patients who had undergone more than 4 cycles of FOLFIRINOX. We reviewed baseline CT (B-CT), 1st follow-up CT (1st-CT), and the preoperative or last follow-up CT (L-CT) and determined tumor size changes according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1). Extra-pancreatic perineural invasion (EPNI) and resectability using NCCN 2019 guideline were evaluated. Subgroup analysis by baseline resectability was performed. RESULTS: B-CT included resectable (n = 25, 23.2%), borderline (n = 55, 29.1%), locally advanced (n = 44, 23.3%), and metastatic (n = 65, 34.4%) PAC. Seventy-four patients had undergone surgery (39.2%) with an 83.8% (62/74) R0 resection. For operability, resectable status at L-CT (hazard ratio (HR) 65.5; 95% confidence interval (CI) 5.0-865; P = 0.002), RECIST (partial response) at 1st-CT (HR 3.6; 95% CI 1.1-11.7; P = 0.032), and baseline borderline resectability (HR 8.6; 95% CI 1.6-46.4; P = 0.013) were important predictors. Based on a size reduction cut-off of 22.2%, the area under the receiver operating characteristic (ROC) curve (Az) was 0.761 (sensitivity = 70.3%, specificity = 74.8%). In subgroup analysis, RECIST (partial response) at 1st-CT was a significant predictor of locally advanced PAC (HR 32; 95% CI 4.5-227, P 0.001), and the optimal cut-off was 22.2% (Az = 0.914; sensitivity = 100%, specificity = 75%). Baseline tumor size ([Formula: see text] 4 cm) (HR 5.6, 95% CI 1.3-24.3, P = 0.022) and unresectable status at 1st-CT (HR 4.8, 95% CI 1.1-20.6, P = 0.035) were significantly associated with margin-positive resection. CONCLUSION: Both baseline and follow-up CT findings are useful to predict conversion surgery for PAC after FOLFIRINOX.

CT for lymph node staging of Colon cancer: not only size but also location and number of lymph node count.

PURPOSE: To evaluate the diagnostic accuracy of imaging features to predict lymph node status of colon cancer using CT. METHODS: This was a retrospective study from 2 tertiary hospitals in South Korea and Netherlands. 317 Colon cancer patients who underwent primary surgical treatment were included. Number of lymph nodes according to the anatomical location, size, cluster, degree of attenuation, shape, presence of internal heterogeneity and ill-defined margin of the lymph node were assessed and compared according to histological lymph node status. RESULTS: The largest short diameter of lymph node and presence of internal heterogeneity of lymph node showed significant association with malignant lymph node status (P < 0.001 and P = 0.041, respectively). The ROC curve analysis revealed AUC of 0.703 for the largest short diameter of lymph node (P < 0.001), and AUC of the presence of internal heterogeneity was 0.630 (P < 0.001). In addition, our study showed that a total number of lymph nodes, regardless of size, (P = 0.022) and number of lymph nodes in peritumoral area (P < 0.001) and along the mesenteric vessels (P < 0.001) on CT demonstrated significant association with malignant status of lymph nodes in colon cancer. CONCLUSIONS: There were significant associations between lymph node status and imaging features of lymph nodes on CT in colon cancer patients. The largest short diameter of lymph node and presence of internal heterogeneity can be used to predict the malignant status of lymph node in colon cancer patients. Also, the number of lymph nodes near the colonic tumor should be considered in assessment of colon cancer lymph node involvement on CT.

Switching Monopolar No-Touch Radiofrequency Ablation Using Octopus Electrodes for Small Hepatocellular Carcinoma: A Randomized Clinical Trial.

INTRODUCTION: A switching monopolar no-touch radiofrequency ablation (RFA) technique is used for small hepatocellular carcinoma (HCC); however, there have not been any randomized clinical trials comparing this technique to the conventional RFA technique. OBJECTIVE: This study aims to compare the results of two RFA techniques, and to comparatively identify more effective methods to reduce the progression of local tumors associated with small HCC (≤2.5 cm). METHODS: This prospective randomized clinical trial (NCT03375281) recruited a total of 116 participants (M:F, 93:23; 68.3 ± 8.4 years) between October 2016 and September 2017. The primary outcome was the cumulative incidence of local tumor progression (LTP) after RFA. Secondary outcomes included technical success rate, technique efficacy, and RFA procedure characteristics. Kaplan-Meier analysis and the Cox proportional hazard regression model were used. RESULTS: The mean follow-up period was 24.1 months. A sufficient ablative margin was more frequently achieved in the no-touch RFA group (57/60 = 95%) than in the conventional RFA group (50/64 = 78.1%) on immediate follow-up CT (p = 0.01). The cumulative incidence of LTP in the no-touch RFA group was significantly lower than that in the conventional RFA group (p = 0.02). In multivariable analysis, no-touch RFA was the only predictive factor for LTP (p = 0.04, hazard ratio = 0.2, 95% confidence interval = 0.04-0.94). CONCLUSIONS: A switching monopolar no-touch RFA technique is a favorable treatment option and provides lower LTP after RFA compared with conventional RFA for small HCC.

Preoperative assessment of the resectability of pancreatic ductal adenocarcinoma on CT according to the NCCN Guidelines focusing on SMA/SMV branch invasion.

OBJECTIVES: For patients with pancreatic adenocarcinoma (PAC), adequate determination of disease extent is critical for optimal management. We aimed to evaluate diagnostic accuracy of CT in determining the resectability of PAC based on 2020 NCCN Guidelines. METHODS: We retrospectively enrolled 368 consecutive patients who underwent upfront surgery for PAC and preoperative pancreas protocol CT from January 2012 to December 2017. The resectability of PAC was assessed based on 2020 NCCN Guidelines and compared to 2017 NCCN Guidelines using chi-square tests. Overall survival (OS) was estimated using the Kaplan-Meier method and compared using log-rank test. R0 resection-associated factors were identified using logistic regression analysis. RESULTS: R0 rates were 80.8% (189/234), 67% (71/106), and 10.7% (3/28) for resectable, borderline resectable, and unresectable PAC according to 2020 NCCN Guidelines, respectively (p < 0.001). The estimated 3-year OS was 28.9% for borderline resectable PAC, which was significantly lower than for resectable PAC (43.6%) (p = 0.004) but significantly higher than for unresectable PAC (0.0%) (p < 0.001). R0 rate was significantly lower in patients with unresectable PAC according to 2020 NCCN Guidelines (10.7%, 3/28) than in those with unresectable PAC according to the previous version (31.7%, 20/63) (p = 0.038). In resectable PAC, tumor size ≥ 3 cm (p = 0.03) and abutment to portal vein (PV) (p = 0.04) were independently associated with margin-positive resection. CONCLUSIONS: The current NCCN Guidelines are useful for stratifying patients according to prognosis and perform better in R0 prediction in unresectable PAC than the previous version. Larger tumor size and abutment to PV were associated with margin-positive resection in patients with resectable PAC. KEY POINTS: • The updated 2020 NCCN Guidelines were useful for stratifying patients according to prognosis. • The updated 2020 NCCN Guidelines performed better in the prediction of margin-positive resection in unresectable cases than the previous version. • Tumor size ≥ 3 cm and abutment to the portal vein were associated with margin-positive resection in patients with resectable pancreatic adenocarcinoma.

Reducing Pain by Artificial Ascites Infusion During Radiofrequency Ablation for Subcapsular Hepatocellular Carcinoma.

PURPOSE: To evaluate therapeutic effects of artificial ascites (AA) infusion in patients with subcapsular hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA) and to determine whether this infusion can reduce pain. METHODS AND MATERIALS: From 2011 to 2016, 123 patients with treatment-naïve single subcapsular HCC (≤ 2.5 cm) who underwent RFA were retrospectively included. Patients were divided into two groups according to AA infusion. After RFA, medical records were used to analyze pain scores during a 24-h period and to determine the opioid used that compared using Mann-Whitney U test. We also conducted subgroup analysis of the patients with HCCs located adjacent to parietal peritoneum. After follow-up period, we analyzed local tumor progression (LTP) and recurrence-free survival using Kaplan-Meier method. RESULTS: AA was infused in 76 patients (61.8%, 76/123). Pain score using numeric rating scale (NRS) was significantly lower in AA infusion group than in control group (2.54 ± 2.8 vs. 3.66 ± 3.2, p = 0.048). Dose of opioids used was not significantly different between two groups (1.62 ± 3.4 mg vs. 1.66 ± 3 mg, p = 0.698). However, in subgroup analysis (N = 45), NRS score and dose of opioids used were significantly lower in AA infusion group (p = 0.03, p = 0.032, respectively). LTP rate was not significantly different between two groups (p = 0.673). CONCLUSION: AA infusion was an effective and safe way to reduce pain when performing RFA for subcapsular HCC. In particular, in patients with subcapsular HCC adjacent to parietal peritoneum, dose of opioid to use pain control was significantly lower with AA infusion.

Tumor Stiffness Measurements on MR Elastography for Single Nodular Hepatocellular Carcinomas Can Predict Tumor Recurrence After Hepatic Resection.

BACKGROUND: Tumor stiffness (TS), measured by magnetic resonance elastography (MRE), could be associated with tumor mechanical properties and tumor grade. PURPOSE: To determine whether TS obtained using MRE is associated with survival in patients with single nodular hepatocellular carcinoma (HCC) after hepatic resection (HR). STUDY TYPE: Retrospective. POPULATION: In all, 95 patients with pathologically confirmed HCCs. FIELD STRENGTH/SEQUENCE: 1.5T/3D spin-echo echo-planar imaging MRE. ASSESSMENT: TS values of the whole tumor (TS-WT) and of a solid portion of the tumor (TS-SP) after excluding the necrotic area were measured on stiffness maps. Known imaging prognostic factors of HCC were also analyzed. After surgery, pathologic findings were evaluated from resected pathology specimens. STATISTICAL TESTS: Fisher's exact test and the Mann-Whitney U-test were performed to determine the significance of differences according to the tumor grade. Overall survival (OS) / recurrence-free survival (RFS) analyses were performed using Kaplan-Meier analyses and Cox multivariable models. RESULTS: The average TS-WT was 2.14 ± 0.74 kPa, and the average TS-SP was 2.51 ± 1.07 kPa. The cumulative incidence of RFS was 73.1%, 63.1%, and 57.3% at 1, 3, and 5 years, respectively. The TS-WT, TS-SP, and tumor size (≥5 cm) were significant prognostic factors for RFS (P < 0.001; P < 0.001; P = 0.017, respectively). The estimated overall 1-, 3-, and 5-year survival rates were 95.7%, 86.9%, and 80.8%, respectively. The alpha-fetoprotein changes, platelets, tumor size (≥5 cm), and vascular invasion in pathology were significant predictive factors for overall survival (all P < 0.05). Tumor necrosis, TS-WT, TS-SP, and vascular invasion in pathology were significantly correlated with poorly differentiated HCC (all P < 0.05). DATA CONCLUSION: The TS-WT, TW-SP, and tumor size (≥5 cm) were significant predictive factors of RFS after HR in patients with HCC. Level of Evidence Technical Efficacy Stage 5 J. MAGN. RESON. IMAGING 2021;53:587-596.

Important CT and histopathological findings for recurrence and overall survival in patients with pancreatic ductal adenocarcinoma who underwent surgery after neoadjuvant FOLFIRINOX.

OBJECTIVES: To investigate important factors for recurrence-free survival (RFS) and overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDA) who underwent surgery after neoadjuvant FOLFIRINOX using CT and histopathological findings. MATERIALS AND METHODS: Sixty-nine patients with PDA who underwent surgery after neoadjuvant FOLFIRINOX were retrospectively included. All patients underwent baseline and first follow-up CT. Two reviewers assessed the CT findings and resectability based on the NCCN guideline. They graded extrapancreatic perineural invasion (EPNI) using a 3-point scale focused on 5 routes. Clinical and histopathological results, such as T- and N-stage, tumor regression grade (TRG) using the College of American Pathology (CAP) grading system, and resection status, were also investigated. Kaplan-Meier methods were used for RFS and OS. The Cox proportional hazard model and logistic regression model were used to identify significant predictive factors. RESULTS: There were 57 patients (82.6%) without residual tumors (R0) and 12 patients (17.4%) with residual tumors (R1 or R2). The median RFS was 13 months (range 0~22 months). For RFS, EPNI on baseline CT (hazard ratio (HR) 2.53, 95% confidence interval (CI) 1.116-5.733, p = 0.026) and TRG (HR 1.76, 95% CI 1.000-3.076, p = 0.046) were important predictors of early recurrence. The mean OS was 48 months (range 11~35 months). For OS, TRG (HR 1.05, 95% CI 1.251-6.559, p = 0.013) was a significant factor. However, there were no independent predictors for residual tumors according to the CT findings. CONCLUSION: EPNI on baseline CT and TRG were important prognostic factors for tumor recurrence. In addition, TRG was also an important prognostic factor for OS. KEY POINTS: • CT and histopathological findings are helpful for predicting early recurrence and poor survival. • EPNI on baseline CT (HR 2.53, p = 0.026) is an important predictor of early recurrence. • The TRG is an important prognostic factor for early recurrence (HR 1.76, p = 0.046) and poor survival (HR 1.05, p = 0.013).

Prediction of microvascular invasion of hepatocellular carcinoma: value of volumetric iodine quantification using preoperative dual-energy computed tomography.

BACKGROUND: To investigate the potential value of volumetric iodine quantification using preoperative dual-energy computed tomography (DECT) for predicting microvascular invasion (MVI) of hepatocellular carcinoma (HCC). METHODS: This retrospective study included patients with single HCC treated through surgical resection who underwent preoperative DECT. Quantitative DECT features, including normalized iodine concentration (NIC) to the aorta and mixed-energy CT attenuation value in the arterial phase, were three-dimensionally measured for peritumoral and intratumoral regions: (i) layer-by-layer analysis for peritumoral layers (outer layers 1 and 2; numbered in close order from the tumor boundary) and intratumoral layers (inner layers 1 and 2) with 2-mm layer thickness and (ii) volume of interest (VOI)-based analysis with different volume coverage (tumor itself; VOIO1, tumor plus outer layer 1; VOIO2, tumor plus outer layers 1 and 2; VOII1, tumor minus inner layer 1; VOII2, tumor minus inner layers 1 and 2). In addition, qualitative CT features, including peritumoral enhancement and tumor margin, were assessed. Qualitative and quantitative CT features were compared between HCC patients with and without MVI. Diagnostic performance of DECT parameters of layers and VOIs was assessed using receiver operating characteristic curve analysis. RESULTS: A total of 36 patients (24 men, mean age 59.9 ± 8.5 years) with MVI (n = 14) and without MVI (n = 22) were included. HCCs with MVI showed significantly higher NICs of outer layer 1, outer layer 2, VOIO1, and VOIO2 than those without MVI (P = 0.01, 0.04, 0.02, 0.02, respectively). Among the NICs of layers and VOIs, the highest area under the curve was obtained in outer layer 1 (0.747). Qualitative features, including peritumoral enhancement and tumor margin, and the mean CT attenuation of each layer and each VOI were not significantly different between HCCs with and without MVI (both P >  0.05). CONCLUSIONS: Volumetric iodine quantification of peritumoral and intratumoral regions in arterial phase using DECT may help predict the MVI of HCC.