Watershed Hepatocellular Carcinomas: The Risk of Incomplete Response following Transhepatic Arterial Chemoembolization

Tumor Size and Watershed Area Correlate with Incomplete Treatment and Tumor Progression after Selective Radioembolization for Hepatocellular Carcinoma

PURPOSE

To identify factors of incomplete treatment after segmental transarterial radioembolization (TARE) for treatment-naive and solitary hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A total of 75 consecutive patients (age, 68.5 years [SD ± 8.0]; 25/75 [33.3%] women) with treatment-naive, solitary HCC underwent segmental or subsegmental TARE with glass microspheres (tumor size, 3.8 cm [SD ± 2.2]; administered dose, 222.6 Gy [SD ± 123.9]) at a single institution from November 2015 to June 2022. Radiologic response and progression-free survival (PFS) were assessed as per modified Response Evaluation Criteria in Solid Tumors.

RESULTS

Complete treatment was achieved in 48 of 75 (64.0%) patients (mean follow-up, 33.2 months [SD ± 27.4]). Patients with incomplete treatment (27/75, 36%) presented with larger tumor size (5.0 [SD ± 2.5] vs 3.1 [SD ± 1.6] cm; P = .0001), with more tumors located in the watershed zone (81.5% vs 41.7%; P = .001). These patients were less likely to be bridged to transplant or resection (22.2% vs 52.1%; P = .015). Watershed tumors demonstrated worse target tumor PFS (median PFS, 19 months vs not reached; P = .0104) and overall PFS (9.1 months vs not reached; P = .0077). Watershed location was associated with worse PFS among tumors >3 cm in size (8.4 months vs not reached; P = .035) but not in tumors ≤3 cm in size (52.2 months vs not reached; P = .915).

CONCLUSIONS

Tumor size and watershed location were associated with incomplete treatment after segmental TARE for HCC. Watershed tumors were associated with worse PFS, particularly tumors larger than 3 cm. These tumors may require careful treatment planning and repeated treatments to ensure a durable response.

Quantitative differences in volumetric calculations for radiation dosimetry in segmental Y90 treatment planning using hybrid angiography-CT compared with anatomic segmentation

OBJECTIVE

To compare treatment volumes reconstructed from hybrid Angio-CT catheter-directed infusion imaging and Couinaud anatomic model as well as the implied differences in Y-90 radiation dosimetry.

METHODS

Patients who underwent transarterial radioembolization (TARE) using Y-90 glass microspheres with pretreatment CT or MRI imaging as well as intraprocedural angiography-CT (Angio-CT) were analysed. Treatment volumes were delineated using both tumoural angiosomes (derived from Angio-CT) and Couinaud anatomic landmarks. Segmental and lobar treatment volumes were calculated via semi-automated contouring software. Volume and dose differences were compared by the two-tailed Student t test or Wilcoxon signed-rank test. Factors affecting volume and dose differences were assessed via simple and/or multiple variable linear regression analysis.

RESULTS

From September 2018 to March 2021, 44 patients underwent 45 lobar treatments and 38 patients received 56 segmental treatments. All target liver lobes and all tumours were completely included within the field-of-view by Angio-CT. Tumour sizes ranged between 1.1 and 19.5 cm in diameter. Segmental volumes and treatment doses were significantly different between the Couinaud and Angio-CT volumetry methods (316 vs 404 mL, P < .0001 and 253 vs 212 Gy, P < .01, respectively). Watershed tumours were significantly correlated with underestimated volumes by the Couinaud anatomic model (P < .001). There was a significant linear relationship between tumour diameter and percent volume difference (R2 = 0.44, P < .0001). The Couinaud model overestimated volumes for large tumours that exhibited central hypovascularity/necrosis and for superselected peripheral tumours.

CONCLUSIONS

Angio-CT may confer advantages over the Couinaud anatomic model and enable more accurate, personalized dosimetry for TARE.

ADVANCES IN KNOWLEDGE

Angio-CT may confer advantages over traditional cross-sectional and cone-beam CT imaging for selective internal radiation therapy planning.

A novel method for predicting hepatocellular carcinoma response to chemoembolization using an intraprocedural CT hepatic arteriography-based enhancement mapping: a proof-of-concept analysis

BACKGROUND

To evaluate the feasibility of a novel approach for predicting hepatocellular carcinoma (HCC) response to drug-eluting beads transarterial chemoembolization (DEB-TACE) using computed tomography hepatic arteriography enhancement mapping (CTHA-EM) method.

METHODS

This three-institution retrospective study included 29 patients with 46 HCCs treated with DEB-TACE between 2017 and 2020. Pre- and posttreatment CTHA-EM images were generated using a prototype deformable registration and subtraction software. Relative tumor enhancement (T_Post/pre-RE) defined as the ratio of tumor enhancement to normal liver tissue was calculated to categorize tumor response as residual (T_Post-RE > 1) versus non-residual (T_Post-RE ≤ 1) enhancement, which was blinded compared to the response assessment on first follow-up imaging using modified RECIST criteria. Additionally, for tumors with residual enhancement, CTHA-EM was evaluated to identify its potential feeding arteries.

RESULTS

CTHA-EM showed residual enhancement in 18/46 (39.1%) and non-residual enhancement in 28/46 (60.9%) HCCs, with significant differences on T_Post-RE (3.05 ± 2.4 versus 0.48 ± 0.23, respectively; p < 0.001). The first follow-up imaging showed non-complete response (partial response or stable disease) in 19/46 (41.3%) and complete response in 27/46 (58.7%) HCCs. CTHA-EM had a response prediction sensitivity of 94.7% (95% CI, 74.0-99.9) and specificity of 100% (95% CI, 87.2-100). Feeding arteries to the residual enhancement areas were demonstrated in all 18 HCCs (20 arteries where DEB-TACE was delivered, 2 newly developed collaterals following DEB-TACE).

CONCLUSION

CTHA-EM method was highly accurate in predicting initial HCC response to DEB-TACE and identifying feeding arteries to the areas of residual arterial enhancement.

Limitations of Fluorine 18 Fluoromisonidazole in Assessing Treatment-induced Tissue Hypoxia after Transcatheter Arterial Embolization of Hepatocellular Carcinoma: A Prospective Pilot Study

Purpose To determine the variance and correlation with tumor viability of fluorine 18 (¹⁸F) fluoromisonidazole (FMISO) uptake in hepatocellular carcinoma (HCC) prior to and after embolization treatment. Materials and Methods In this single-arm, single-center, prospective pilot study between September 2016 and March 2017, participants with at least one tumor measuring 1.5 cm or larger with imaging or histologic findings diagnostic for HCC were enrolled (five men; mean age, 68 years; age range, 61-76 years). Participants underwent ¹⁸F-FMISO PET/CT before and after bland embolization of HCC. A tumor-to-liver ratio (TLR) was calculated by using standardized uptake values of tumor and liver. The difference in mean TLR before and after treatment was compared by using a Wilcoxon rank sum test, and correlation between TLR and tumor viability was assessed by using the Spearman rank correlation coefficient. Results Four participants with five tumors were included in the final analysis. The median tumor diameter was 3.2 cm (IQR, 3.0-3.9 cm). The median TLR before treatment was 0.97 (IQR, 0.88-0.98), with a variance of 0.02, and the median TLR after treatment was 0.85 (IQR, 0.79-1), with a variance of 0.01; both findings indicate a narrow range of ¹⁸F-FMISO uptake in HCC. The Spearman rank correlation coefficient was 0.87, indicating a high correlation between change in TLR and nonviable tumor. Conclusion Although there was a correlation between change in TLR and response to treatment, the low signal-to-noise ratio of ¹⁸F-FMISO in the liver limited its use in HCC. Keywords: Molecular Imaging-Clinical Translation, Embolization, Abdomen/Gastrointestinal, Liver Clinical trial registration no. NCT02695628 © RSNA, 2022.

Combined transarterial iodized oil injection and computed tomography-guided thermal ablation for hepatocellular carcinoma: utility of the iodized oil retention pattern

Purpose

To investigate whether the iodized oil (Lipiodol, Guerbet Group, Villepinte, France) retention pattern influences the treatment efficacy of combined transarterial Lipiodol injection (TLI) and thermal ablation in patients with hepatocellular carcinoma (HCC).

Methods

Data of 198 patients (280 HCC lesions), who underwent TLI plus computed tomography (CT)-guided thermal ablation at three separate medical institutions between June 2014 and September 2020, were reviewed and analyzed. The Lipiodol retention pattern was classified as complete or incomplete based on non-enhanced CT at the time of ablation. The primary outcome was local recurrence-free survival (LRFS) for lesions; the secondary outcome was overall survival (OS) for patients. Propensity score matching (PSM) was performed using a caliper width of 0.1 between the two groups. Differences in LRFS and OS between the two groups were compared using the log-rank test.

Results

A total of 133 lesions exhibited a complete Lipiodol retention pattern, while 147 exhibited an incomplete pattern. After PSM analysis of baseline characteristics of the lesions, 121 pairs of lesions were matched. LRFS was significantly longer for lesions exhibiting complete retention than for those exhibiting incomplete retention (P = 0.030). After PSM analysis of patient baseline characteristics, 74 pairs of patients were matched. There was no significant difference in OS between the two groups (P = 0.456).

Conclusion

Lipiodol retention patterns may influence the treatment efficacy of combined TLI and thermal ablation for HCC lesions. However, a survival benefit for the Lipiodol retention pattern among HCC patients was not observed and needs further confirmation.

In Vitro Model for Simulating Drug Delivery during Balloon-Occluded Transarterial Chemoembolization

Background: Balloon-occluded transarterial chemoembolization (B-TACE) has emerged as a safe and effective procedure for patients with liver cancer, which is one of the deadliest types of cancer worldwide. B-TACE consist of the transcatheter intraarterial infusion of chemotherapeutic agents, followed by embolizing particles, and it is performed with a microballoon catheter that temporarily occludes a hepatic artery. B-TACE relies on the blood flow redistribution promoted by the balloon-occlusion. However, flow redistribution phenomenon is not yet well understood. Methods: This study aims to present a simple in vitro model (IVM) where B-TACE can be simulated. Results: By visually analyzing the results of various clinically-realistic experiments, the IVM allows for the understanding of balloon-occlusion-related hemodynamic changes and the importance of the occlusion site. Conclusion: The IVM can be used as an educational tool to help clinicians better understand B-TACE treatments. This IVM could also serve as a base for a more sophisticated IVM to be used as a research tool.

Locoregional Combined With Systemic Therapies for Advanced Hepatocellular Carcinoma: An Inevitable Trend of Rapid Development

Despite the application of antiviral drugs and improved surveillance tools, the number of patients diagnosed with hepatocellular carcinoma (HCC) at an advanced stage and with a dismal prognosis is still on the rise. Systemic treatment with multiple multitargeted tyrosine kinase inhibitors (TKIs), such as sorafenib, has been a widely utilized approach for a decade. In addition, the use of a combination of TKIs with other types of compounds, including immune checkpoint inhibitors (ICIs) and antiangiogenic inhibitors, has shown efficacy in treating advanced HCC. However, the presence of intolerable adverse events, low disease response and control rates, and relative short overall survival of such combinatory therapies makes novel or optimized therapies for advance HCC urgently needed. Locoregional therapy (transarterial chemoembolization, and thermal ablation) can destroy primary tumors and decrease tumor burden and is widely used for HCC management. This type of treatment modality can result in local hypoxia and increased vascular permeability, inducing immunogenic effects by releasing tumor antigens from dying cancer cells and producing damage-associated molecular patterns that facilitate antiangiogenic therapy and antitumor immunity. The combination of systemic and locoregional therapies may further produce synergistic effects without overlapping toxicity that can improve prognoses for advanced HCC. In preliminary studies, several combinations of therapeutic modes exhibited promising levels of safety, feasibility, and antitumor effects in a clinical setting and have, thus, garnered much attention. This review aims to provide a comprehensive, up-to-date overview of the underlying mechanisms of combined systemic and locoregional therapies in the treatment of advanced HCC, commenting on both their current status and future direction.

Transarterial Yttrium-90 Radioembolization of Hepatocellular Carcinoma Perfused by the Cystic Artery: Multi-institutional Feasibility Study

PURPOSE

To assess the safety and efficacy of transarterial yttrium-90 radioembolization via the cystic artery for patients with hepatocellular carcinoma (HCC) adjacent to the gallbladder with cystic artery supply.

MATERIALS AND METHODS

This retrospective study included 17 patients treated at 4 institutions. Patients with HCC perfused by the cystic artery who received ablative-dose radioembolization were included. Median tumor size was 3.8 cm (range, 2.0-8.8 cm). Fourteen patients (82%) had Child-Pugh class A cirrhosis and 3 (18%) had class B cirrhosis. Adverse events, tumor response, and time to progression were analyzed.

RESULTS

Median dose to the tissue perfused by the cystic artery was 340 Gy (range, 200-720 Gy). There were no occurrences of acute cholecystitis warranting invasive intervention. Four patients (24%) experienced transient right upper quadrant pain, with symptom resolution within 3 mo. Six patients (35%) exhibited gallbladder wall edema on follow-up imaging. Two (12%) and 0 grade 3/4 increases in alkaline phosphatase and bilirubin were observed, respectively. Follow-up imaging demonstrated complete response in 13 target tumors (76%) and partial response in 4 (24%). There were no cases of target tumor progression during a median follow-up of 9 mo (range, 3-72 mo).

CONCLUSIONS

Direct infusion of 90Y microspheres via the cystic artery appears to have an acceptable safety profile, without resulting in acute cholecystitis warranting invasive intervention. In selected patients with HCC in whom other treatments may be contraindicated and the tumor is supplied via the cystic artery, treatment with selective ablative radioembolization can be considered.

Assessment in the Survival Outcome After Transarterial Chemoembolization Combined with Cryoablation for Hepatocellular Carcinoma (Diameter > 4cm) Based on the Albumin-Bilirubin Grade and Platelet-Albumin-Bilirubin ‎grade: ‎ A Preliminary Study

Objective

Based on the albumin-bilirubin (ALBI) and platelet-albumin-bilirubin (PALBI) grade to assess the long-term outcomes of patients with large hepatocellular carcinoma (HCC) after transarterial chemoembolization combined with cryoablation (TACE-CRA).

Materials and Methods

We studied 86 patients with HCC nodules (up to 3 HCCs with maximum diameters of 4.1–12.0 cm) who subsequently underwent TACE-CRA from July 2007 to August 2018. The overall survival (OS) was compared between groups classified by ALBI and PALBI grade. Baseline characteristics were collected to identify the risk factors for determination of poor OS after TACE-CRA. The prognostic performances of CTP class, ALBI and PALBI grade were compared.

Results

After a median follow-up time of 33.8 months, 41 patients had died. The cumulative1-, 3- and 5-year OS rates were 74.5%, 38.0% and 29.3%, respectively. Stratified according to ALBI grade, the cumulative 3- and 5-year OS rates were 41.2% and 41.2% in grade 1, respectively, and 20.9% and 9.8% in grades 2–3, respectively (P < 0.001). Stratified according to PALBI grade, the cumulative 3- and 5-year OS rates were 41.2% and 37.5% in grade 1, respectively, and 36.3% and 21.2% in grades 2–3, respectively (P = 0.002). Multivariate analysis results showed that older age, and ALBI grade 2–3 were associated with overall mortality. ALBI grade demonstrated significantly greater area under the curve values than CTP class and PALBI in predicting 1-, 3- and 5-year OS.

Conclusion

ALBI grade offers accurate prediction of long-term outcome for patients with HCC (diameter > 4 cm) after TACE-CRA.

Red Flags, Pitfalls, and Cautions in Y90 Radiotherapy

Radioembolization with yttrium-90 (Y90) microspheres is increasingly used to palliate patients with liver-dominant malignancy. With appropriate patient selection, this outpatient treatment is efficacious with limited toxicity profile. This article reviews common scenarios that can present in daily practice including evaluation of liver functions, evaluation of previous therapies, integrating Y90 into ongoing systemic therapy, determining performance status, and considering retreatment for patients who have already undergone Y90 who have hepatic dominant progression. Finally, we address the importance of evaluating tumors in potential watershed zones to maximize treatment response by using c-arm computed tomography. Many of these potential variables can overlap in an individual patient. By considering these factors individually, the consulting Interventional Radiologist can present a thorough treatment plan with a full description of expected outcomes and toxicities to clinic patients.

Combination transarterial chemoembolization and microwave ablation improves local tumor control for 3- to 5-cm hepatocellular carcinoma when compared with transarterial chemoembolization alone

PURPOSE

To compare transarterial chemoembolization (TACE) monotherapy to combination TACE and microwave ablation (MWA) for local control of 3- to 5-cm hepatocellular carcinoma (HCC).

METHODS

Patients with HCC between 3 and 5 cm treated with TACE monotherapy or combination TACE + MWA at a single institution between 2007 and 2016 were retrospectively reviewed. Twenty-four HCCs (median diameter 3.8 cm) in 16 patients (13 males; median age 64 years) were treated using TACE monotherapy. Combination TACE + MWA was used to treat 23 HCCs (median diameter 4.2 cm) in 22 patients (18 males; median age 61 years). Microwave ablation was performed at a target time of two weeks following TACE. Individual tumors were followed by serial contrast-enhanced CT or MR. Response to treatment was evaluated on a tumor-by-tumor basis using mRECIST criteria with the primary outcome being local tumor progression (LTP). Data were analyzed using Fisher's exact test for categorical variables and Wilcoxon rank sum test for continuous variables. Time to LTP was estimated with the Kaplan-Meier method.

RESULTS

Relative to TACE monotherapy, TACE + MWA provided a trend toward both a lower rate of LTP (34.8% vs. 62.5%, p = 0.11) and a higher complete response rate (65.2% vs. 37.5%; p = 0.12). Time to LTP (22.3 months vs. 4.2 months; p = 0.001) was significantly longer in the TACE + MWA group compared to TACE monotherapy.

CONCLUSIONS

Combination therapy with TACE and microwave ablation improves local control and increases time to LTP for 3-5 cm HCC.

Hepatic Arterial Embolization Using Cone Beam CT with Tumor Feeding Vessel Detection Software: Impact on Hepatocellular Carcinoma Response

PURPOSE

Dedicated tumor feeding vessel detection software (TFVDS) using cone beam CT has shown a higher sensitivity to detect tumor feeding vessels during hepatic arterial embolization (HAE) of hepatocellular carcinoma (HCC) compared to 2D imaging. Our primary hypothesis was that HCC tumors treated with HAE guided by a TFVDS would show more complete response (CR) than when treated with 2D imaging alone. Secondary analysis of the impact on X-ray exposure was performed.

MATERIALS AND METHODS

Nineteen males and 8 females (median age: 69 year, 46-85) with 44 tumors (median size: 38 mm, 6-100) treated with selective HAE between January 2013 and December 2014 were included. Exclusion criteria were: extra-hepatic supply, >4 tumors, tumor size >10 cm, and adjunctive local therapy. Baseline patient and procedure characteristics were reviewed. Differences in CR per modified Response Evaluation Criteria in Solid Tumors were assessed by univariate and multivariate analyses for tumor size, number, location, particles size, and use of TFVDS.

RESULTS

Median imaging follow-up was 20.1 months (2-33). Use of TFVDS (13 patients, 19 tumors) was the only factor predictive of CR (OR = 3.85 [CI95%: 1.09, 13.67], p = 0.04) on univariate analysis but not on multivariate analysis (OR = 3.26 [0.87, 12.23], p = 0.08). A higher rate of CR was observed for HAE using TFVDS guidance versus 2D imaging alone (68.4%, 13-19, vs. 36%, 9-25, p = 0.03). Median dose area product was lower when TFVDS was used (149.7 Gy.cm², 38-365, vs. 227.8 Gy.cm², 85.3-468.6, p = 0.05).

CONCLUSIONS

HCC embolized with TFVDS may result in improved local tumor response without increasing the dose exposure.