Factors Associated With Complete Pathologic Necrosis of Hepatocellular Carcinoma on Explant Evaluation After Locoregional Therapy: A National Analysis Using the UNOS Database

Harnessing Electrophiles In Vivo: A Pilot Study in Swine Using a Hydrophobic Radiopaque Formulation of 2-Propylpentanoyl Chloride

Manipulating biology through chemistry is older than the discipline of chemistry itself. Traditionally, selectivity of oral or intravenous drugs relied on preferential drug-receptor binding. A novel approach exploiting image-guided techniques to impart spatial selectivity opens up a wide range of new possibilities for study and manipulation of biology. Motivated initially by the poor prognosis for solid tumors such as liver cancer, we demonstrate the use of an extreme form of in vivo chemistry for targeted delivery of 2-propylpentanoyl chloride in a swine model. The ensuing reaction in tissue devitalizes it by multiple mechanisms with lasting effects and, critically, demonstrates very low systemic exposure compared to controls. This work points toward a new, powerful strategy for investigating the interface between chemistry and biology in vivo.

Chemistry Outside the Flask: Redefining Selectivity In Vivo with Image Guidance

Fundamental to drug dosing and formulation strategies are the therapeutic index and maintaining a plasma concentration within a safe but therapeutic window. This holds true for oral, intravenous, transdermal, and intramuscular delivery methods. A key factor in plasma concentration is the half-life for any drug, because this affects the appropriate dose. Drugs with a very short half-life pose a particular challenge. Therefore, highly reactive compounds are not generally used for therapeutic purposes. However, targeted delivery under direct visualization, combined with cessation of blood flow in the area, could potentially allow the use of these highly reactive compounds. Such a strategy requires that little or none of the material reach systemic circulation to cause off-target toxicities. If this approach were applied to cancer, multiple mechanisms could be activated to disrupt cellular metabolism. We report our experience in a swine model using a strong electrophile, dichloroacetyl chloride, dissolved in a hydrophobic vehicle and delivered to the liver with high spatial selectivity using a microcatheter. Compared with positive controls, very little of the reaction product, dichloroacetate, a known inhibitor of pyruvate dehydrogenase kinase, was detected in plasma over 4 h. We further demonstrated persistence of the material for 24 h with highly localized and well-defined coagulative necrosis in the target vascular bed, without evidence of dose-limiting toxicity over the duration of the experiment.

CT/MRI LI-RADS 2024 Update: Treatment Response Assessment

With the rising incidence of hepatocellular carcinoma, there has been increasing use of local-regional therapy (LRT) to downstage or bridge to transplant, for definitive treatment, and for palliation. The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) Treatment Response Assessment (TRA) algorithm provides guidance for step-by-step tumor assessment after LRT and standardized reporting. Current evidence suggests that the algorithm performs well in the assessment of tumor response to arterial embolic and loco-ablative therapies and fair when assessing response to radiation-based therapies, with limited data to validate the latter. Both evidence-based and expert-based refinements of the algorithm are needed to improve its diagnostic accuracy after varying types of LRT. This review provides an overview of the challenges and limitations of the LI-RADS TRA algorithm version 2017 and discusses the refinements introduced in the updated 2024 LI-RADS algorithm for CT/MRI.

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.

Pushing the limits of treatment for hepatocellular carcinoma

PURPOSE OF REVIEW

We review existing and newer strategies for treatment and surveillance of hepatocellular carcinoma (HCC) both pre and postliver transplantation.

SUMMARY

HCC is rising in incidence and patients are often diagnosed at later stages. Consequently, there is a need for treatment strategies which include collaboration of multiple specialties. Combinations of locoregional, systemic, and surgical therapies are yielding better postliver transplantation (post-LT) outcomes for patients with HCC than previously seen. Tumor biology (tumor size, number, location, serum markers, response to therapy) can help identify patients who are at high risk for HCC recurrence posttransplantation and may expand transplant eligibility for some patients.

Downstaging Hepatocellular Carcinoma before Transplantation: Role of Immunotherapy Versus Locoregional Approaches

Hepatocellular carcinoma (HCC) continues to be a leading cause of cancer-related death in the United States. With advances in locoregional therapy for unresectable HCC during the last 2 decades and the recent expansion of transplant criteria for HCC, as well as ongoing organ shortages, patients are spending more time on the waitlist, which has resulted in an increased usage of locoregional therapies. The plethora of molecularly targeted therapies and immune checkpoint inhibitors under investigation represent the new horizon of treatment of HCC not only in advanced stages but also potentially at every stage of diagnosis and management.

Outcomes of Radiation Segmentectomy for Hepatocellular Carcinoma in Patients with Non-Alcoholic Fatty Liver Disease versus Chronic Viral Hepatitis

Purpose

To compare the outcomes of radiation segmentectomy for early-stage hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD) versus hepatitis C virus (HCV).

Materials and Methods

A retrospective analysis of consecutive patients with NAFLD- or HCV-related HCC treated with radiation segmentectomy from 01/2017-06/2022 was performed. Eligibility criteria included solitary tumor ≤8 cm or up to 3 HCC ≤3 cm, ECOG 0-1, and absence of vascular invasion or extrahepatic spread. Imaging best response was assessed per modified Response Evaluation Criteria in Solid Tumors. Target tumor and overall progression, time-to-progression (TTP), and overall survival (OS) were calculated. All outcomes were censored for liver transplantation (LT). Complete pathologic response (CPN) was assessed in patients who underwent LT.

Results

Of 142 patients included (NAFLD: 61; HCV: 81), most had cirrhosis (NAFLD: 87%; HCV: 86%) and small tumors (median size NAFLD: 2.3 cm; HCV: 2.5 cm). Patients with NAFLD had higher BMI (p<0.001) and worse ALBI scores (p=0.003). Patients with HCV were younger (p<0.001) and had higher AFP levels (p=0.034). Median radiation dose (NAFLD: 508 Gy; HCV: 452 Gy) and specific activity (NAFLD: 700 Bq; HCV: 698 Bq) were similar between cohorts. Objective response was 100% and 97% in the NAFLD and HCV cohorts, respectively. Target tumor progression occurred in 1 (2%) NAFLD and 8 (10%) HCV patients. Target tumor TTP was not met for either cohort. Overall progression occurred in 23 (38%) NAFLD and 39 (48%) HCV patients. Overall TTP was 17.4 months (95% CI 13.5-22.2) in NAFLD and 13.5 months (95% CI 0.4-26.6) in HCV patients (p=0.86). LT was performed in 27 (44%) NAFLD and 33 (41%) HCV patients, with a CPN rate of 63% and 54%, respectively. OS was not met in the NAFLD cohort and was 53.9 months (95% CI 32.1-75.7) in the HCV cohort (p=0.15).

Conclusion

Although NAFLD and HCV are associated with different mechanisms of liver injury, patients with early-stage HCC treated with radiation segmentectomy achieve comparable outcomes.