The Importance of Optimal Thermal Ablation Margins in Colorectal Liver Metastases: A Systematic Review and Meta-Analysis of 21 Studies.

BACKGROUND: Colorectal cancer (CRC) is the second most common cause of cancer-related deaths in the US. Thermal ablation (TA) can be a comparable alternative to partial hepatectomy for selected cases when eradication of all visible tumor with an ablative margin of greater than 5 mm is achieved. This systematic review and meta-analysis aimed to encapsulate the current clinical evidence concerning the optimal TA margin for local cure in patients with colorectal liver metastases (CLM). METHODS: MEDLINE, EMBASE, and the CENTRAL databases were systematically searched from inception until 1 May 2023, in accordance with the PRISMA Guidelines. Measure of effect included the risk ratio (RR) with 95% confidence interval (CI) using the random-effects model. RESULTS: Overall, 21 studies were included, comprising 2005 participants and 2873 ablated CLMs. TA with margins less than 5 mm were associated with a 3.6 times higher risk for LTP (n = 21 studies, RR: 3.60; 95% CI: 2.58-5.03; p-value < 0.001). When margins less than 5 mm were additionally confirmed by using 3D software, a 5.1 times higher risk for LTP (n = 4 studies, RR: 5.10; 95% CI: 1.45-17.90; p-value < 0.001) was recorded. Moreover, a thermal ablation margin of less than 10 mm but over 5 mm remained significantly associated with 3.64 times higher risk for LTP vs. minimal margin larger than 10 mm (n = 7 studies, RR: 3.64; 95% CI: 1.31-10.10; p-value < 0.001). CONCLUSIONS: This meta-analysis solidifies that a minimal ablation margin over 5 mm is the minimum critical endpoint required, whereas a minimal margin of at least 10 mm yields optimal local tumor control after TA of CLMs.

Ablative radiation alone in stage I lung cancer produces an adaptive systemic immune response: insights from a prospective stud.

Stereotactic ablative body radiation (SABR) delivers high rates of local control in early-stage non-small cell lung cancer (NSCLC); however, systemic immune effects are poorly understood. Here, we evaluate the early pathologic and immunologic effects of SABR. Blood/core-needle tumor biopsies were collected from six patients with stage I NSCLC before and 5-7 days after SABR (48 Gy/4 or 50 Gy/5 fractions). Serial blood was collected up to 1-year post-SABR. We used immunohistochemistry to evaluate pathological changes, immune-cell populations (CD8, FoxP3), and PD-L1/PD-1 expression within the tumor. We evaluated T-cell receptor (TCR) profile changes in the tumor using TCR sequencing. We used the MANAFEST (Mutation-Associated Neoantigen Functional Expansion of Specific T-cells) assay to detect peripheral neoantigen-specific T-cell responses and dynamics. At a median follow-up of 40 months, 83% of patients (n=5) were alive without tumor progression. Early post-SABR biopsies showed viable tumor and similar distribution of immune-cell populations as compared with baseline samples. Core-needle samples proved insufficient to detect population-level TCR-repertoire changes. Functionally, neoantigen-specific T-cells were detected in the blood prior to SABR. A subset of these patients had a transient increase in the frequency of neoantigen-specific T-cells between 1 week and 3-6 months after SABR. SABR alone could induce a delayed, transient neoantigen-specific T-cell immunologic response in patients with stage I NSCLC.

Relationship of Hepatocellular Carcinoma Stage and Hepatic Function to Health-Related Quality of Life: A Single Center Analysis.

Health-related quality of life (HRQoL) is known to be an important prognostic indicator and clinical endpoint for patients with hepatocellular carcinoma (HCC). However, the correlation of the Barcelona Clinic Liver Cancer (BCLC) stage with HRQoL in HCC has not been previously studied. We examined the relationship between BCLC stage, Child-Pugh (CP) score, and Eastern Cooperative Oncology Group (ECOG) performance status on HRQoL for patients who presented at a multidisciplinary liver cancer clinic. HRQoL was assessed using the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) questionnaire. Fifty-one patients met our inclusion criteria. The FACT-Hep total and subscales showed no significant association with BCLC stages (p = 0.224). Patients with CP B had significantly more impairment in FACT-Hep than patients with CP A. These data indicate that in patients with HCC, impaired liver function is associated with reduced quality of life, whereas the BCLC stage poorly correlates with quality of life metrics. Impairment of quality of life is common in HCC patients and further studies are warranted to determine the impact of early supportive interventions on HRQoL and survival outcomes.

Conventional vs. Drug-Eluting Beads Transarterial Chemoembolization for Unresectable Hepatocellular Carcinoma-A Propensity Score Weighted Comparison of Efficacy and Safety.

This study compared the efficacy and safety of conventional transarterial chemoembolization (cTACE) with drug-eluting beads (DEB)-TACE in patients with unresectable hepatocellular carcinoma (HCC). This retrospective analysis included 370 patients with HCC treated with cTACE (n = 248) or DEB-TACE (n = 122) (January 2000-July 2014). Overall survival (OS) was assessed using uni- and multivariate Cox proportional hazards models and Kaplan-Meier analysis. Additionally, baseline imaging was assessed, and clinical and laboratory toxicities were recorded. Propensity score weighting via a generalized boosted model was applied to account for group heterogeneity. There was no significant difference in OS between cTACE (20 months) and DEB-TACE patients (24.3 months, ratio 1.271, 95% confidence interval 0.876-1.69; p = 0.392). However, in patients with infiltrative disease, cTACE achieved longer OS (25.1 months) compared to DEB-TACE (9.2 months, ratio 0.366, 0.191-0.702; p = 0.003), whereas DEB-TACE proved more effective in nodular disease (39.4 months) than cTACE (18 months, ratio 0.458, 0.308-0681; p = 0.007). Adverse events occurred with similar frequency, except for abdominal pain, which was observed more frequently after DEB-TACE (101/116; 87.1%) than cTACE (119/157; 75.8%; p = 0.02). In conclusion, these findings suggest that tumor morphology and distribution should be used as parameters to inform decisions on the selection of embolic materials for TACE for a more personalized treatment planning in patients with unresectable HCC.

Bronchial Artery Chemoembolization With Radiopaque Doxorubicin Eluding Beads in Patients With Malignant Hemoptysis from Metastatic Lung Cancer.

Purpose:This pilot study was designed to assess the technical feasibility and safety of bronchial artery chemoembolization with radiopaque doxorubicin eluting beads (DEB-BACE) in patients with malignant hemoptysis from pulmonary metastasis. Materials & Methods: Four patients underwent DEB-BACE using 70-150 µm radiopaque DEB (LC Beads LUMI, Boston Scientific). Beads delivery and deposition were assessed under fluoroscopy and cone beam computed tomography (CT), respectively. Results: All 4 procedures were technically successful. Beads delivery and deposition were successfully visualized under fluoroscopy and cone beam CT guidance in all cases. Hemoptysis was resolved after embolization in all 4 patients. There were no adverse events or immediate or early complications after DEB-BACE. Two patients (50%) required repeat DEB-BACE within 1 week due to recurrent hemoptysis, and 1 patient had DEB-BACE 1.5 years later due to recurrent hemoptysis from the contralateral lung. All targeted lesions decreased in size in follow-up studies (mean 16 months, range 1-33 months). One patient died of progressive cancer disease invading the heart 1 month after DEB-BACE. Conclusions: DEB-BACE using radiopaque LC Beads LUMI loaded with doxorubicin is technically feasible and safe for controlling hemoptysis and cancer progression in patients with metastatic lung tumors. Visualization of beads delivery under fluoroscopy and deposition of beads under cone beam CT facilitate delivery of beads and embolization of bronchial arteries.

Analysis of Tumor Burden as a Biomarker for Patient Survival with Neuroendocrine Tumor Liver Metastases Undergoing Intra-Arterial Therapies: A Single-Center Retrospective Analysis.

PURPOSE: To assess the value of quantitative analysis of tumor burden on baseline MRI for prediction of survival in patients with neuroendocrine tumor liver metastases (NELM) undergoing intra-arterial therapies. MATERIALS AND METHODS: This retrospective single-center analysis included 122 patients with NELM who received conventional (n = 74) or drug-eluting beads, (n = 20) chemoembolization and radioembolization (n = 28) from 2000 to 2014. Overall tumor diameter (1D) and area (2D) of up to 3 largest liver lesions were measured on baseline arterially contrast enhanced MR images. Three-dimensional quantitative analysis was performed using the qEASL tool (IntelliSpace Portal Version 8, Philips) to calculate enhancing tumor burden (the ratio between enhancing tumor volume and total liver volume). Based on Q-statistics, patients were stratified into low tumor burden (TB) or high TB. RESULTS: The survival curves were significantly separated between low TB and high TB groups for 1D (p < 0.001), 2D (p < 0.001) and enhancing TB (p = 0.008) measurements, with, respectively, 2.7, 2.6 and 2.2 times longer median overall survival (MOS) in the low TB group (p < 0.001, p < 0.001 and p = 0.008). Multivariate analysis showed that 1D, 2D, and enhancing TB were independent prognostic factors for MOS, with respective hazard ratios of 0.4 (95%CI: 0.2-0.6, p < 0.001), 0.4 (95%CI: 0.3-0.7, p < 0.001) and 0.5 (95%CI: 0.3-0.8, p = 0.003). CONCLUSION: The overall tumor diameter, overall tumor area, and enhancing tumor burden are strong prognostic factors of overall survival in patients with neuroendocrine tumor liver metastases undergoing intra-arterial therapies.

CT-Guided Celiac Ganglion Block for Neurogenic Gastrointestinal Dysmotility.

PURPOSE: To determine whether celiac ganglion block can serve as a diagnostic test for dysautonomia as the cause of gastrointestinal dysmotility-related symptoms. MATERIALS AND METHODS: This was an institutional review board-approved, prospective, single-arm, registered study, from January 2020 to May 2021, and included patients aged 14-85 years with gastrointestinal symptoms of food intolerance, abdominal pain, or angina. Patients with nonneurogenic causes (ie, chronic cholecystitis, peptic ulcer disease, gastroesophageal reflux, and malabsorption syndrome) were excluded. All 15 patients underwent computed tomography-guided celiac ganglion block with 100 mg of liposomal bupivacaine. Patients filled out the dysautonomia-validated questionnaire Composite Autonomic Symptom Score 31 (COMPASS-31) before and after intervention. Differences (before vs after) were compared with the exact permutation method. RESULTS: Fifteen women (median age, 17 years; range, 14-41 years) were included. Average COMPASS-31 score improved significantly, from baseline 11 (SD ± 2.8) to 4 (SD ± 1.9) (improvement, 7 points ± 2.8; P < .001). All patients reported significant reduction in abdominal angina. Fourteen of the 15 patients (93%) reported complete resolution, and 14 of 15 (93%) reported a significant reduction in non-postprandial abdominal pain (P < .01). Only 1 patient reported no improvement. Eight of those 14 patients (57%) reported complete resolution of abdominal pain. There was a significant improvement in functional scores (vomiting, P = .01; constipation frequency, P = .02; constipation severity, P < .01; and nausea, P < .01). The rate of minor and major adverse events was 13% and 0%, respectively, per the Society of Interventional Radiology adverse event classification. CONCLUSIONS: Celiac ganglion block is a safe diagnostic tool for confirming dysautonomia as the underlying condition in patients with gastrointestinal dysmotility-related symptoms. It could provide early diagnosis, lead to definitive treatment (ganglionectomy) earlier, or obviate unnecessary surgery.

Three-Dimensional Quantitative Tumor Response and Survival Analysis of Hepatocellular Carcinoma Patients Who Failed Initial Transarterial Chemoembolization: Repeat or Switch Treatment?

OBJECTIVES: The purpose of this study was to assess treatment responses and evaluate survival outcomes between responders and non-responders after each transarterial chemoembolization (TACE) session using the 3D quantitative criteria of the European Association for the Study of the Liver (qEASL) in hepatocellular carcinoma (HCC) patients. METHODS: A total of 94 consecutive patients who underwent MR imaging before and after TACE were retrospectively included. Volumetric tumor enhancement (qEASL) was expressed in cubic centimeters (cm3). The Kaplan-Meier method with the log-rank test was used to calculate the overall survival (OS) for the non-/responders. RESULTS: In total, 28 (29.8%) patients showed a response after the first TACE. These responders demonstrated a clear trend toward longer OS compared with the non-responders (36.7 vs. 21.5 months, p = 0.071). Of the 43 initial non-responders who underwent a second TACE within 3 months and had complete follow-up imaging, 15/43 (34.9%) achieved a response, and their median OS was significantly longer than that of the 28 non-responders to the second TACE (47.8 vs. 13.6 months, p = 0.01). Furthermore, there was no significant difference in OS between the 28 patients who achieved a response after the first TACE and the 15 initial non-responders who achieved a response after the second TACE (36.7 vs. 47.8 months, p = 0.701). The difference in OS between the responders and non-responders after the third TACE was not significant (11.4 months vs. 13.5 months, p = 0.986). CONCLUSION: Our study quantitatively demonstrated that a second TACE can be beneficial in terms of tumor response and survival for HCC patients who do not initially respond to TACE.

Response assessment methods for patients with hepatic metastasis from rare tumor primaries undergoing transarterial chemoembolization.

PURPOSE: This study assessed the response to conventional transarterial chemoembolization (cTACE) in patients with liver metastases from rare tumor primaries using one-dimensional (1D) and three-dimensional (3D) quantitative response assessment methods, and investigate the relationship of lipiodol deposition in predicting response. MATERIALS AND METHODS: This retrospective bicentric study included 16 patients with hepatic metastases from rare tumors treated with cTACE between 2002 and 2017. Multi-phasic MR imaging obtained before and after cTACE was used for assessment of response. Response evaluation criteria in solid tumors (RECIST) and modified-RECIST (mRECIST) were utilized for 1D response assessment, and volumetric RECIST (vRECIST) and enhancement-based quantitative European Association for Study of the Liver EASL (qEASL) were used for 3D response assessment. The same day post-cTACE CT scan was analyzed to quantify intratumoral lipiodol deposition (%). RESULTS: The mean and standard deviation (SD) of diameter of treated lesions per targeted area was 7.5 ± 5.4 cm, and the mean and SD of number of metastases in each targeted area was 4.2 ± 4.6. cTACE was technically successful in all patients, without major complications. While RECIST and vRECIST methods did not allocate patients with partial response, mRECIST and qEASL identified patients with partial response. Intratumoral lipiodol deposition significantly predicted treatment response according qEASL (R2 = 0.470, p < 0.01), while no association was shown between lipiodol deposition within treated tumor area and RECIST or mRECIST (p > 0.212). CONCLUSION: 3D quantitative volumetric response analysis can be used for stratification of response to cTACE in patients with hepatic metastases originating from rare primary tumors. Lipiodol deposition could potentially be used as an early surrogate to predict response to cTACE.

Radiofrequency Ablation versus Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma Awaiting Liver Transplant: An Analysis of the Scientific Registry of Transplant Recipients.

PURPOSE: To evaluate differences in waitlist mortality and dropout in liver transplant candidates with hepatocellular carcinoma (HCC) who undergo radiofrequency (RF) ablation versus transarterial chemoembolization (TACE). MATERIAL AND METHODS: From 2004 to 2013, 11,824 patients with HCC in the Scientific Registry of Transplant Recipients who underwent RF ablation or TACE were included and followed until December 31, 2019, or 5 years, whichever came first, and were stratified by the Milan criteria. Competing risk and Cox regression analyses to compare waitlist mortality and dropout were performed using adjusted hazard ratios (asHRs, with RF ablation group as reference). Regression models were adjusted for age, race, sex, calculated Model for End-Stage Liver Disease score, tumor size, and number. RESULTS: There was no difference in waitlist mortality and dropout for patients outside the Milan criteria (n = 1,226) who underwent TACE (19.2%) or RF ablation (19.0%) (asHR, 0.91; 95% CI, 0.79-1.03). There was also no difference for patients inside the Milan criteria (n = 10,598) in waitlist mortality/dropout (TACE 13.4% vs RF ablation 12.9%) (asHR, 1.29; 95% CI, 0.79-2.09). A subgroup analysis within the Milan criteria demonstrated no difference between TACE and RF ablation treatments in patients with a single tumor of ≤3 cm (asHR, 0.92; 95% CI, 0.77-1.10), with a single tumor of >3 cm (asHR, 1.03; 95% CI, 0.79-1.34), or with >1 tumor (asHR, 0.89; 95% CI, 0.72-1.09). CONCLUSIONS: Using the national registry data, no difference was found in waitlist mortality and dropout for transplant candidates with HCC who received TACE versus RF ablation.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors.

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.

Quaternary nanoparticles enable sustained release of bortezomib for hepatocellular carcinoma.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) represents the third leading cause of cancer-related mortality in the world. Over the past two decades, there has been minimal improvement in therapies as well as clinical outcomes for patients with Barcelona Clinic Liver Cancer (BCLC)-B. These patients are treated with local interventions, including transarterial chemoembolization. Current methodologies only allow sustained intratumoral release measured in hours. Methodologies to allow sustained local release of the drug cargo over days to weeks are acutely needed. We hypothesize that tumor response as well as outcomes of patients with BCLC-B can be improved through utilization of a highly cytotoxic agent delivered with a sustained release platform. APPROACH AND RESULTS: High-throughput drug screening across 40 HCC patient-derived organoids identified bortezomib (BTZ) as a highly cytotoxic small molecule for HCC. We designed and manufactured sustained release BTZ nanoparticles (BTZ-NP) using a flash nanocomplexation/nanoprecipitation process. We quantified the release profile and tested the anti-tumoral effects in vivo. The BTZ-NP formulation demonstrated a sustained release of BTZ of 30 days. This BTZ-NP formulation was highly effective in controlling tumor size and improved survival in vivo in three animal models of HCC, including when delivered via the hepatic artery, as we envision its delivery in patients. In addition, the BTZ-NP formulation was superior to treatment with doxorubicin-drug eluting beads. CONCLUSIONS: The BTZ-NP formulation provides a potent and safe treatment of HCC via a localized delivery approach. These results warrant additional preclinical studies to advance this technology to human clinical trials.

Optimization of the BCLC Staging System for Locoregional Therapy for Hepatocellular Carcinoma by Using Quantitative Tumor Burden Imaging Biomarkers at MRI.

Background Patients with intermediate- and advanced-stage hepatocellular carcinoma (HCC) represent a highly heterogeneous patient collective with substantial differences in overall survival. Purpose To evaluate enhancing tumor volume (ETV) and enhancing tumor burden (ETB) as new criteria within the Barcelona Clinic Liver Cancer (BCLC) staging system for optimized allocation of patients with intermediate- and advanced-stage HCC to undergo transarterial chemoembolization (TACE). Materials and Methods In this retrospective study, 682 patients with HCC who underwent conventional TACE or TACE with drug-eluting beads from January 2000 to December 2014 were evaluated. Quantitative three-dimensional analysis of contrast-enhanced MRI was performed to determine thresholds of ETV and ETB (ratio of ETV to normal liver volume). Patients with ETV below 65 cm3 or ETB below 4% were reassigned to BCLC Bn, whereas patients with ETV or ETB above the determined cutoffs were restratified or remained in BCLC Cn by means of stepwise verification of the median overall survival (mOS). Results This study included 494 patients (median age, 62 years [IQR, 56-71 years]; 401 men). Originally, 123 patients were classified as BCLC B with mOS of 24.3 months (95% CI: 21.4, 32.9) and 371 patients as BCLC C with mOS of 11.9 months (95% CI: 10.5, 14.8). The mOS of all included patients (including the BCLC B and C groups) was 15 months (95% CI: 12.3, 17.2). A total of 152 patients with BCLC C tumors were restratified into a new BCLC Bn class, in which the mOS was then 25.1 months (95% CI: 21.8, 29.7; P < .001). The mOS of the remaining patients (ie, BCLC Cn group) (n = 222; ETV ≥65 cm3 or ETB ≥4%) was 8.4 months (95% CI: 6.1, 11.2). Conclusion Substratification of patients with intermediate- and advanced-stage hepatocellular carcinoma according to three-dimensional quantitative tumor burden identified patients with a survival benefit from transarterial chemoembolization before therapy. © RSNA, 2022 Online supplemental material is available for this article.

Incidence and Contemporary Management of Delayed Bleeding Following Pancreaticoduodenectomy.

BACKGROUND: Delayed bleeding after pancreaticoduodenectomy (PD) is a life-threatening complication. However, the optimal management remains unclear. We summarize our experience of the management of delayed bleeding after PD and define the outcomes associated with different types of management. METHODS: All patients who underwent a PD between January 1987 and June 2020 at Johns Hopkins University were retrospectively reviewed. Delayed bleeding was defined as bleeding on or after postoperative day 5 following PD. Incidence, outcomes, and trends were reported. RESULTS: Among the 6201 patients that underwent PD, delayed bleeding occurred in 130 (2.1%) at a median of 12 days (IQR: 9, 24) postoperation. The pattern of bleeding was classified as intraluminal (51.5%), extraluminal (40.8%), and mixed (7.7%). A clinically relevant postoperative pancreatic fistula and an intraabdominal abscess preceded the delayed bleeding in 43.1% and 31.5% of cases, respectively. Arterial pseudoaneurysm or bleeding from peripancreatic vessels was the most common reason (54.6%) with the gastroduodenal artery being the most common source (18.5%). Endoscopy, angiography, and reoperation were performed as a first-line approach in 35.4%, 52.3%, and 6.2% of patients, respectively. The overall mortality was 16.2% and decreased over the study period (p < 0.01). CONCLUSIONS: Delayed bleeding following PD remains a life-threatening complication. The most common location of delayed bleeding is from the gastroduodenal artery. Angiography with embolization should be the initial approach for urgent bleeding with surgical re-exploration reserved for unstable patients or failed control of bleeding after interventional angiography or endoscopy.

Impact of the COVID-19 Pandemic on Liver Cancer Staging at a Multidisciplinary Liver Cancer Clinic.

To compare liver cancer resectability rates before and during the COVID-19 pandemic. Background: Liver cancers usually present with nonspecific symptoms or are diagnosed through screening programs for at-risk patients, and early detection can improve patient outcomes. In 2020, the COVID-19 pandemic upended medical care across all specialties, but whether the pandemic was associated with delays in liver cancer diagnosis is not known. Methods: We performed a retrospective review of all patients evaluated at the Johns Hopkins Multidisciplinary Liver Cancer Clinic from January 2019 to June 2021 with a new diagnosis of suspected or confirmed hepatocellular carcinoma (HCC) or biliary tract cancer (BTC). Results: There were 456 liver cancer patients (258 HCC and 198 BTC). From January 2019 to March 2020 (pre-pandemic), the surgical resectability rate was 20%. The subsequent 6 months (early pandemic), the resectability rate decreased to 11%. Afterward from October 2020 to June 2021 (late pandemic), the resectability rate increased to 27%. The resectability rate early pandemic was significantly lower than that for pre-pandemic and later pandemic combined (11% lower; 95% confidence interval [CI], 2%-20%). There was no significant difference in resectability rates pre-pandemic and later pandemic (7% difference; 95% CI, -3% to 16%). In subgroup analyses, the early pandemic was associated with a larger impact in BTC resectability rates than HCC resectability rates. Time from BTC symptom onset until Multidisciplinary Liver Clinic evaluation increased by over 6 weeks early pandemic versus pre-pandemic (Hazard Ratio, 0.63; 95% CI, 0.44-0.91). Conclusions: During the early COVID-19 pandemic, we observed a drop in the percentage of patients presenting with curable liver cancers. This may reflect delays in liver cancer diagnosis and contribute to excess mortality related to the COVID-19 pandemic.

Lipiodol Deposition and Washout in Primary and Metastatic Liver Tumors After Chemoembolization.

BACKGROUND/AIM: Lipiodol is the key component of conventional trans-arterial chemoembolization. Our aim was to evaluate lipiodol deposition and washout rate after conventional trans-arterial chemoembolization in intrahepatic cholangiocarcinoma and hepatic metastases originating from neuroendocrine tumors and colorectal carcinoma. PATIENTS AND METHODS: This was a retrospective analysis of 44 patients with intrahepatic cholangiocarcinoma and liver metastasis from neuroendocrine tumors or colorectal carcinoma who underwent conventional trans-arterial chemoembolization. Lipiodol volume (cm3) was analyzed on non-contrast computed tomography imaging obtained within 24 h post conventional trans-arterial chemoembolization, and 40-220 days after conventional trans-arterial chemoembolization using volumetric image analysis software. Tumor response was assessed on contrast-enhanced magnetic resonance imaging 1 month after conventional trans-arterial chemoembolization. RESULTS: The washout rate was longer for neuroendocrine tumors compared to colorectal carcinoma, with half-lives of 54.61 days (p<0.00001) and 19.39 days (p<0.001), respectively, with no exponential washout among intrahepatic cholangiocarcinomas (p=0.83). The half-life for lipiodol washout was longer in tumors larger than 300 cm3 compared to smaller tumors (25.43 vs. 22.71 days). Lipiodol wash out half-life was 54.76 days (p<0.01) and 29.45 days (p<0.00001) for tumors with a contrast enhancement burden of 60% or more and less than 60%, respectively. A negative exponential relationship for lipiodol washout was observed in non-responders (p<0.00001). CONCLUSION: Lipiodol washout is a time-dependent process, and occurs faster in colorectal carcinoma tumors, tumors smaller than 300 cm3, tumors with baseline contrast enhancement burden of less than 60%, and non-responding target lesions.