Sintilimab plus bevacizumab combined with radiotherapy as first-line treatment for hepatocellular carcinoma with portal vein tumor thrombus: A multicenter, single-arm, phase 2 study.

BACKGROUND AND AIMS: Systemic treatments are listed as first-line therapies for HCC with portal vein tumor thrombus (PVTT), resulting in modest efficacy. We aimed to evaluate the efficacy and safety of sintilimab plus bevacizumab combined with radiotherapy in HCC with PVTT and to identify prognostic biomarkers. APPROACH AND RESULTS: This open-label, multicenter, single-arm, phase 2 clinical trial was conducted at 3 tertiary hospitals in China. A total of 46 patients with HCC with PVTT were enrolled. All the patients received the first cycle of i.v. sintilimab (200 mg, day 1) plus bevacizumab (15 mg/kg, day 1) within 3 days after enrollment. Radiotherapy (30-50 Gy/10 fractions) was administered after 2 cycles of Sin-Bev. Sin-Bev was disrupted during radiotherapy and resumed 2 weeks after radiotherapy and continued every 3 weeks thereafter until disease progression, unacceptable toxicity, or withdrawal of consent. The primary end point was objective response rate. Patients obtained an objective response rate of 58.7% and a disease control rate of 100%. After a median follow-up time of 26.0 months (95% CI: 24.0-26.0), the median OS was 24.0 months (95% CI: 19.0 to not applicable) and the median progression-free survival was 13.8 months (95% CI: 12.0-21.0), respectively. No unexpected adverse events or treatment-related deaths occurred. Mutations of PCTMD1 were predictive of shorter OS and progression-free survival. CONCLUSIONS: Sintilimab plus bevacizumab combined with radiotherapy provides favorable treatment response and survival outcomes along with an acceptable safety profile in the first-line setting for patients with HCC with PVTT (ClinicalTrials.gov Identifier: NCT05010434).

Charged Gold Nanoparticles for Target Identification-Alignment and Automatic Segmentation of CT Image-Guided Adaptive Radiotherapy in Small Hepatocellular Carcinoma.

Because of the challenges posed by anatomical uncertainties and the low resolution of plain computed tomography (CT) scans, implementing adaptive radiotherapy (ART) for small hepatocellular carcinoma (sHCC) using artificial intelligence (AI) faces obstacles in tumor identification-alignment and automatic segmentation. The current study aims to improve sHCC imaging for ART using a gold nanoparticle (Au NP)-based CT contrast agent to enhance AI-driven automated image processing. The synthesized charged Au NPs demonstrated notable in vitro aggregation, low cytotoxicity, and minimal organ toxicity. Over time, an in situ sHCC mouse model was established for in vivo CT imaging at multiple time points. The enhanced CT images processed using 3D U-Net and 3D Trans U-Net AI models demonstrated high geometric and dosimetric accuracy. Therefore, charged Au NPs enable accurate and automatic sHCC segmentation in CT images using classical AI models, potentially addressing the technical challenges related to tumor identification, alignment, and automatic segmentation in CT-guided online ART.

Palliative radiotherapy versus best supportive care in patients with painful hepatic cancer (CCTG HE1): a multicentre, open-label, randomised, controlled, phase 3 study.

BACKGROUND: Palliative treatment options for painful hepatic cancer can be restricted due to patients eventually becoming refractory to standard treatment. The aim of this study was to determine whether radiotherapy improves hepatic pain from cancer. METHODS: In this open-label, randomised, controlled, phase 3 trial (CCTG HE1) done in nine cancer centres across Canada, we included patients aged 18 years or older with hepatocellular carcinoma or liver metastases, who were refractory to standard treatment, with an Eastern Cooperative Oncology Group performance status of 0-3, with life expectancy of more than 3 months, and pain or discomfort at its worst in the past 24 hours on the Brief Pain Inventory (BPI) of at least 4 out of 10, which was stable for up to 7 days before randomisation. Patients were randomly assigned (1:1), via a minimisation method after stratification by centre and type of cancer (hepatocellular carcinoma vs liver metastases), to single-fraction radiotherapy (8 Gy) to the liver with 8 mg ondansetron (or equivalent) orally and 4 mg dexamethasone orally given 1-2 h before radiotherapy plus best supportive care (including non-opioid or opioid analgesia, or dexamethasone, or a combination of these) or best supportive care alone. The primary endpoint was improvement in patient-reported liver cancer pain or discomfort of at least 2 points on worst pain intensity on the BPI at 1 month after randomisation. All patients with both baseline and 1-month assessments were included in the primary endpoint analysis. Safety was assessed in all patients randomly assigned to treatment. This trial is registered with ClinicalTrials.gov, NCT02511522, and is complete. FINDINGS: Between July 25, 2015, and June 2, 2022, 66 patients were screened and randomly assigned to radiotherapy plus best supportive care (n=33) or best supportive care (n=33). Median age was 65 years (IQR 57-72), 37 (56%) of 66 patients were male, 29 (44%) were female, 43 (65%) had liver metastases, and 23 (35%) had hepatocellular carcinoma (data on race and ethnicity were not collected). As of data cutoff (Sept 8, 2022), median follow-up was 3·2 months (95% CI 3·0-3·4). 24 (73%) of 33 in the radiotherapy plus best supportive care group and 18 (55%) of 33 in the best supportive care only group completed baseline and 1-month assessments. An improvement in hepatic pain of at least 2 points in worst pain intensity on the BPI at 1 month was seen in 16 (67%) of 24 patients in the radiotherapy plus best supportive care group versus four (22%) of 18 patients in the best supportive care group (p=0·0042). The most common grade 3-4 adverse events within 1 month after randomisation were abdominal pain (three [9%] of 33 in the radiotherapy group vs one [3%] of 33 in best supportive care group) and ascites (two [6%] vs one [3%]). No serious adverse events or treatment-related deaths were observed. INTERPRETATION: Single-fraction radiotherapy plus best supportive care improved pain compared with best supportive care alone in patients with liver cancer, and could be considered a standard palliative treatment. FUNDING: Canadian Cancer Society.

PC4-mediated Ku complex PARylation facilitates NHEJ-dependent DNA damage repair.

Radiotherapy is one of the mainstay treatments for hepatocellular carcinoma (HCC). However, a substantial number of patients with HCC develop radioresistance and eventually suffer from tumor progression or relapse, which is a major impediment to the use of radiotherapy. Therefore, elucidating the mechanisms underlying radioresistance and identifying novel therapeutic targets to improve patient prognosis are important in HCC management. In this study, using in vitro and in vivo models, laser microirradiation and live cell imaging methods, and coimmunoprecipitation assays, we report that a DNA repair enhancer, human positive cofactor 4 (PC4), promotes nonhomologous end joining-based DNA repair and renders HCC cells resistant to radiation. Mechanistically, PC4 interacts with poly (ADP-ribose) polymerase 1 and directs Ku complex PARylation, resulting in the successful recruitment of the Ku complex to damaged chromatin and increasing the efficiency of nonhomologous end joining repair. Clinically, PC4 is highly expressed in tumor tissues and is correlated with poor prognosis in patients with HCC. Taken together, our data suggest that PC4 is a DNA repair driver that can be targeted to radiosensitize HCC cells.

Tumor cell-intrinsic MELK enhanced CCL2-dependent immunosuppression to exacerbate hepatocarcinogenesis and confer resistance of HCC to radiotherapy.

BACKGROUND: The outcome of hepatocellular carcinoma (HCC) is limited by its complex molecular characteristics and changeable tumor microenvironment (TME). Here we focused on elucidating the functional consequences of Maternal embryonic leucine zipper kinase (MELK) in the tumorigenesis, progression and metastasis of HCC, and exploring the effect of MELK on immune cell regulation in the TME, meanwhile clarifying the corresponding signaling networks. METHODS: Bioinformatic analysis was used to validate the prognostic value of MELK for HCC. Murine xenograft assays and HCC lung metastasis mouse model confirmed the role of MELK in tumorigenesis and metastasis in HCC. Luciferase assays, RNA sequencing, immunopurification-mass spectrometry (IP-MS) and coimmunoprecipitation (CoIP) were applied to explore the upstream regulators, downstream essential molecules and corresponding mechanisms of MELK in HCC. RESULTS: We confirmed MELK to be a reliable prognostic factor of HCC and identified MELK as an effective candidate in facilitating the tumorigenesis, progression, and metastasis of HCC; the effects of MELK depended on the targeted regulation of the upstream factor miR-505-3p and interaction with STAT3, which induced STAT3 phosphorylation and increased the expression of its target gene CCL2 in HCC. In addition, we confirmed that tumor cell-intrinsic MELK inhibition is beneficial in stimulating M1 macrophage polarization, hindering M2 macrophage polarization and inducing CD8 + T-cell recruitment, which are dependent on the alteration of CCL2 expression. Importantly, MELK inhibition amplified RT-related immune effects, thereby synergizing with RT to exert substantial antitumor effects. OTS167, an inhibitor of MELK, was also proven to effectively impair the growth and progression of HCC and exert a superior antitumor effect in combination with radiotherapy (RT). CONCLUSIONS: Altogether, our findings highlight the functional role of MELK as a promising target in molecular therapy and in the combination of RT therapy to improve antitumor effect for HCC.

Efficacy of stereotactic ablative radiotherapy in patients with oligometastatic hepatocellular carcinoma: A phase II study.

BACKGROUND & AIMS: Stereotactic ablative radiotherapy (SABR) can extend survival and offers the potential for cure in some patients with oligometastatic disease (OMD). However, limited evidence exists regarding its use in oligometastatic hepatocellular carcinoma (HCC). We aimed to prospectively investigate the efficacy and safety of SABR in patients with oligometastatic HCC. METHODS: We enrolled patients with controlled primary HCC and one to five metastatic lesions amenable to SABR. The primary endpoint was treatment efficacy defined as overall survival (OS) and progression-free survival (PFS). The secondary endpoints included time to local progression, objective response rate, disease control rate, toxicities, and quality of life (QOL), assessed using the EORTC QLQ-C30 before, and 0, 1, and 3 months after SABR. RESULTS: Overall, 40 consecutive patients received SABR on 62 lesions between 2021 and 2022. The most common locations for OMD were the lungs (48.4%), lymph nodes (22.6%), and bone (17.7%). After a median follow-up of 15.5 months, the 2-year OS was 80%. Median PFS was 5.3 months, with 1- and 2-year PFS rates of 21.2% and 0%, respectively. A shorter time to OMD from the controlled primary independently correlated with PFS (p = 0.039, hazard ratio 2.127) alongside age, Child-Pugh class, and alpha-fetoprotein (p = 0.002, 0.004, 0.019, respectively). The 2-year time to local progression, objective response rate, and disease control rate were 91.1%, 75.8%, and 98.4%, respectively. Overall, 10% of patients experienced acute toxicity, and 7.5% experienced late toxicity, with no grade 3+ toxicity. All QOL scores remained stable, whereas the patients without systemic treatments had improved insomnia and social functioning scores. CONCLUSIONS: SABR is an effective and feasible option for oligometastatic HCC that leads to excellent local tumor control and improves survival without adversely affecting QOL. IMPACT AND IMPLICATIONS: Stereotactic ablative radiotherapy (SABR) is a non-invasive treatment approach capable of efficiently ablating the target lesion; however, neither the oligometastatic disease concept nor the potential benefits of SABR have been well-defined in hepatocellular carcinoma (HCC). According to this study, SABR is an effective and safe treatment option for oligometastatic HCC, yielding excellent local tumor control and survival improvement without worsening patients' quality of life, regardless of tumor sites. We also demonstrated that patients with a later presentation of OMD from the controlled primary and lower alpha-fetoprotein levels achieved better survival outcomes. This is the first prospective study of SABR in oligometastatic HCC, providing insights for the development of novel strategies to improve oncologic outcomes. CLINICAL TRIAL NUMBER: NCT05173610.

Transarterial Radioembolization for Management of Hepatocellular Carcinoma.

Transarterial radioembolization (TARE) with Yttrium-90 (Y90) is a growing area of study due to its benefits in early-, intermediate-, and late-stage hepatocellular carcinoma. Treatment intent, including curative therapy, bridging to transplant, and downstaging disease, informs treatment approach and dosimetry goals. Radiation lobectomy (RL) and radiation segmentectomy (RS) are the 2 main forms of Y90 administration which have shown improved survival outcomes with the development of personalized dosimetry. RS aims to achieve complete pathological necrosis with dose escalation and RL aims for local disease control as well as induction of contralateral lobe hypertrophy to improve hepatic reserve. Furthermore, TARE has been validated in head-to-head comparison to other locoregional and systemic therapies. Lastly, early potential exists for combination therapy between TARE and immune checkpoint inhibitors for advanced stage disease.

A Pilot Study of Pembrolizumab in Combination With Y90 Radioembolization in Subjects With Poor Prognosis Hepatocellular Carcinoma.

BACKGROUND: Combination checkpoint inhibition therapy with yttrium-90 (Y90) radioembolization represents an emerging area of interest in the treatment of advanced hepatocellular carcinoma (HCC). HCRN GI15-225 is an open-label, single-arm multicenter, pilot study (NCT03099564). METHODS: Eligible patients had poor prognosis, localized HCC defined as having portal vein thrombus, multifocal disease, and/or diffuse disease that were not eligible for liver transplant or surgical resection. Patients received pembrolizumab 200 mg intravenously every 3 weeks in conjunction with glass yttrium-90 (Y90) radioembolization TheraSphere. Primary endpoint was 6-month progression-free survival (PFS6) per RECIST 1.1. Secondary endpoints included time to progression (TTP), objective response rate (ORR), overall survival (OS), and safety/tolerability. RESULTS: Between October 23, 2017 and November 24, 2020, 29 patients were enrolled: 2 were excluded per protocol. Fifteen of the remaining 27 patients were free of progression at 6 months (55.6%; 95% CI, 35.3-74.5) with median PFS 9.95 months (95% CI, 4.14-15.24) and OS 27.30 months (95% CI, 10.15-39.52). One patient was not evaluable for response due to death; among the remaining 26 patients, ORR was 30.8% (95% CI, 14.3-51.8) and DCR was 84.6% (95% CI, 65.1-95.6). CONCLUSION: In patients with localized, poor prognosis HCC, pembrolizumab in addition to glass Y90 radioembolization demonstrated promising efficacy and safety consistent with prior observations (ClinicalTrials.gov Identifier: NCT03099564; IRB Approved: 16-3255 approved July 12, 2016).

Concurrent Atezolizumab Plus Bevacizumab and High-Dose External Beam Radiotherapy for Highly Advanced Hepatocellular Carcinoma.

BACKGROUND: Atezolizumab plus bevacizumab (atezo-bev) has been recommended for advanced hepatocellular carcinoma (HCC). High-dose external beam radiotherapy (RT) is recognized for its excellent local tumor control. The efficacy and safety of concurrent atezo-bev with RT for highly advanced HCC has been minimally explored. METHODS: In this preliminary retrospective study, we assessed patients with highly advanced HCC, characterized by Vp4 portal vein thrombosis or tumors exceeding 50% of liver volume, who received concurrent atezo-bev and RT (group A). Group A included 13 patients who received proton radiation at a dose of 72.6 GyE in 22 fractions, and one patient who received photon radiation at a dose of 54 Gy in 18 fractions. This group was compared with 34 similar patients treated atezo-bev alone as a control (group B). The primary objectives were to evaluate the objective response rate (ORR), overall survival (OS), and safety. RESULTS: Baseline characteristics were similar between groups, except for a higher incidence of Vp4 portal vein thrombosis in group A (78.6% vs. 21.4%, P = .05). Group A achieved a higher ORR (50.0% vs. 11.8%, P < .01) and a longer OS (not reached vs. 5.5 months, P = .01) after a median follow-up of 5.2 months. Multivariate analysis indicated that concurrent RT independently favored longer OS (hazard ratio: 0.18; 95% CI, 0.05-0.63, P < .01). Group A did not increase any grade adverse events (78.6% vs. 58.8%, P = .19) or severe adverse events of grade ≥ 3 (14.3% vs. 14.7%, P = .97) compared to group B. CONCLUSIONS: The concurrent high-dose external beam radiotherapy appears to safely enhance the effectiveness of atezolizumab plus bevacizumab for highly advanced patients with HCC. Further studies are warranted to confirm these findings.

Efficacy and Safety of Radiation Segmentectomy with 90Y Resin Microspheres for Hepatocellular Carcinoma.

Background Limited data are available on radiation segmentectomy (RS) for treatment of hepatocellular carcinoma (HCC) using yttrium 90 (90Y) resin microsphere doses determined by using a single-compartment medical internal radiation dosimetry (MIRD) model. Purpose To evaluate the efficacy and safety of RS treatment of HCC with 90Y resin microspheres using a single-compartment MIRD model and correlate posttreatment dose with outcomes. Materials and Methods This retrospective single-center study included adult patients with HCC who underwent RS with 90Y resin microspheres between July 2014 and December 2022. Posttreatment PET/CT and dosimetry were performed. Adverse events were assessed using the Common Terminology Criteria for Adverse Events, version 5.0. Per-lesion and overall response rates (ie, complete response [CR], objective response, disease control, and duration of response) were assessed at imaging using the Modified Response Evaluation Criteria in Solid Tumors, and overall survival (OS) was assessed using Kaplan-Meier analysis. Results Among 67 patients (median age, 69 years [IQR, 63-78 years]; 54 male patients) with HCC, median tumor absorbed dose was 232 Gy (IQR, 163-405 Gy). At 3 months, per-lesion and overall (per-patient) CR was achieved in 47 (70%) and 41 (61%) of 67 patients, respectively. At 6 months (n = 46), per-lesion rates of objective response and disease control were both 94%, and per-patient rates were both 78%. A total of 88% (95% CI: 79 99) and 72% (95% CI: 58, 90) of patients had a per-lesion and overall duration of response of 1 year or greater. At 1 month, a grade 3 clinical adverse event (abdominal pain) occurred in one of 67 (1.5%) patients. Median posttreatment OS was 26 months (95% CI: 20, not reached). Disease progression at 2 years was lower in the group that received 300 Gy or more than in the group that received less than 300 Gy (17% vs 61%; P = .047), with no local progression in the former group through the end of follow-up. Conclusion Among patients with HCC who underwent RS with 90Y resin microspheres, 88% and 72% achieved a per-lesion and overall duration of response of 1 year or greater, respectively, with one grade 3 adverse event. In patients whose tumors received 300 Gy or more according to posttreatment dosimetry, a disease progression benefit was noted. © RSNA, 2024 Supplemental material is available for this article.

Liver Imaging Reporting and Data System Contrast-Enhanced US Nonradiation Treatment Response Assessment Version 2024.

The American College of Radiology Liver Imaging Reporting and Data System (LI-RADS) standardizes the imaging technique, reporting lexicon, disease categorization, and management for patients with or at risk for hepatocellular carcinoma (HCC). LI-RADS encompasses HCC surveillance with US; HCC diagnosis with CT, MRI, or contrast-enhanced US (CEUS); and treatment response assessment (TRA) with CT or MRI. LI-RADS was recently expanded to include CEUS TRA after nonradiation locoregional therapy or surgical resection. This report provides an overview of LI-RADS CEUS Nonradiation TRA v2024, including a lexicon of imaging findings, techniques, and imaging criteria for posttreatment tumor viability assessment. LI-RADS CEUS Nonradiation TRA v2024 takes into consideration differences in the CEUS appearance of viable tumor and posttreatment changes within and in close proximity to a treated lesion. Due to the high sensitivity of CEUS to vascular flow, posttreatment reactive changes commonly manifest as areas of abnormal perilesional enhancement without washout, especially in the first 3 months after treatment. To improve the accuracy of CEUS for nonradiation TRA, different diagnostic criteria are used to evaluate tumor viability within and outside of the treated lesion margin. Broader criteria for intralesional enhancement increase sensitivity for tumor viability detection. Stricter criteria for perilesional enhancement limit miscategorization of posttreatment reactive changes as viable tumor. Finally, the TRA algorithm reconciles intralesional and perilesional tumor viability assessment and assigns a single LI-RADS treatment response (LR-TR) category: LR-TR nonviable, LR-TR equivocal, or LR-TR viable.

The cumulative antitumor effects of regorafenib and radiotherapy in hepatocellular carcinoma.

Regorafenib is a second-line standard treatment for hepatocellular carcinoma (HCC). However, the efficacy of regorafenib is often limited due to drug resistance, individual differences among patients, and irrational drug use. Radiotherapy (RT) is an important method of localized HCC treatment, and combining RT with other therapies may exert a synergetic antitumor effect. Platelet-derived growth factor receptor-like (PDGFRL) is a tumor suppressor in various solid tumors. However, the function of PDGFRL in HCC is still unknown. In this study, we explored whether regorafenib and RT exert a synergetic effect on the treatment of HCC. The antitumor effect and mechanisms of the combination of regorafenib and RT were verified in a xenograft mouse model in vivo and in HCC cells in vitro. The combination treatment significantly inhibited cell proliferation and promoted apoptosis both in vitro and in vivo. PDGFRL, a potential target of regorafenib, was increased after cumulative treatment in HCC cells, and PDGFRL suppressed HCC cell proliferation and promoted apoptosis by inhibiting STAT3 pathway activation. Furthermore, the cumulative antitumor effect was dependent on the upregulated expression of PDGFRL and inhibition of STAT3 signaling pathway activation in HCC cells. This study increased the understanding of the molecular mechanism underlying the effect of regorafenib plus RT on HCC and provided a theoretical basis for the clinical practice of HCC.

Increased IFN-ß indicates better survival in hepatocellular carcinoma treated with radiotherapy.

Preclinical data suggest that type I interferon (IFN) responsiveness is essential for the antitumor effects of radiotherapy (RT). However, its clinical value remains unclear. This study aimed to explore this from a clinical perspective. In cohort 1, data from 152 hepatocellular carcinoma (HCC) patients who received RT were analyzed. Blood samples were taken 1 day before and 2 weeks after RT. RT was found to increase serum levels of IFN-ß (a subtype of IFN-I) in HCC patients (3.42 ±â€…1.57 to 5.51 ±â€…2.11 pg/ml, P < 0.01), particularly in those with favorable responses. Higher post-RT serum IFN-ß levels (≥4.77 pg/ml) were associated with better progression-free survival (HR = 0.58, P < 0.01). Cohort 2 included 46 HCC patients, including 23 who underwent preoperative RT and 23 matched control HCC who received surgical resection without RT. Formalin-fixed paraffin-embedded samples were obtained. Neoadjuvant RT significantly increased IFN-ß expression in tumor tissues compared to direct surgery (8.13% ±â€…5.19% to 15.10% ±â€…5.89%, P < 0.01). Higher post-RT IFN-ß (>median) indicated better disease-free survival (P = 0.049). Additionally, increased CD11c+MHCII+CD141+ antigen-presenting cell subsets and CD103+CD39+CD8+ tumor-infiltrating lymphocytes were found in the higher IFN-ß group (P = 0.02, P = 0.03), which may contribute to the favorable prognosis in higher IFN-ß group. Collectively, these findings suggest that IFN-ß response activated by radiation may serve as a prognostic biomarker for HCC patients undergoing RT.

Radiotherapy enhances the anti-tumor effect of CAR-NK cells for hepatocellular carcinoma.

BACKGROUND: Chimeric antigen receptor (CAR)-NK cell therapy has shown remarkable clinical efficacy and safety in the treatment of hematological malignancies. However, this efficacy was limited in solid tumors owing to hostile tumor microenvironment (TME). Radiotherapy is commonly used for solid tumors and proved to improve the TME. Therefore, the combination with radiotherapy would be a potential strategy to improve therapeutic efficacy of CAR-NK cells for solid tumors. METHODS: Glypican-3 (GPC3) was used as a target antigen of CAR-NK cell for hepatocellular carcinoma (HCC). To promote migration towards HCC, CXCR2-armed CAR-NK92 cells targeting GPC3 were first developed, and their cytotoxic and migration activities towards HCC cells were evaluated. Next, the effects of irradiation on the anti-tumor activity of CAR-NK92 cells were assessed in vitro and in HCC-bearing NCG mice. Lastly, to demonstrate the potential mechanism mediating the sensitized effect of irradiation on CAR-NK cells, the differential gene expression profiles induced by irradiation were analyzed and the expression of some important ligands for the NK-cell activating receptors were further determined by qRT-PCR and flow cytometry. RESULTS: In this study, we developed CXCR2-armed GPC3-targeting CAR-NK92 cells that exhibited specific and potent killing activity against HCC cells and the enhanced migration towards HCC cells. Pretreating HCC cells with irradiation enhanced in vitro anti-HCC effect and migration activity of CXCR2-armed CAR-NK92 cells. We further found that only high-dose (8 Gy) but not low-dose (2 Gy) irradiation in one fraction could significantly enhanced in vivo anti-HCC activity of CXCR2-armed CAR-NK92 cells. Irradiation with 8 Gy significantly up-regulated the expression of NK cell-activating ligands on HCC cells. CONCLUSIONS: Our results indicate the evidence that irradiation could efficiently enhance the anti-tumor effect of CAR-NK cells in solid tumor model. The combination with radiotherapy would be an attractive strategy to improve therapeutic efficacy of CAR-NK cells for solid tumors.

Managing hepatocellular carcinoma across the stages: efficacy and outcomes of stereotactic body radiotherapy : A retrospective study.

PURPOSE: Hepatocellular carcinoma (HCC) poses a unique challenge due to its predilection for developing on compromised livers, often limiting surgical options. Stereotactic body radiotherapy (SBRT) has emerged as a promising local treatment modality for HCC. This study aims to assess the effectiveness of SBRT in HCC patients not suitable for surgery, focusing on local control, optimal radiation dosing, and prognostic factors. METHODS: In this retrospective analysis, 52 HCC patients treated with SBRT were examined. The study assessed local control, progression-free survival (PFS), and overall survival (OS) while conducting dosimetric analyses. The relationship between mean liver dose and Child-Pugh score (CPS) progression was also explored. RESULTS: SBRT demonstrated 93.4% freedom from local progression (FFLP) at 12 months. Notably, a near minimum dose (D98%) below 61 Gy as an equivalent dose in 2­Gy fractions with α/ß 10 Gy (EQD2α/ß10) was associated with reduced FFLP (p-value 0.034). Logistic regression analysis revealed a dose-response relationship for FFLP and D98% with 95% and 98% probability of FFLP at a dose of 56.9 and 73.1 Gy, respectively. The study observed OS rates of 63.7% at 1 year and 34.3% at 3 years. Patients with portal vein tumor thrombus (PVTT) and larger tumors (≥ 37 cm3) experienced decreased PFS and OS. Multivariate analysis identified PVTT, larger tumor volume, and performance status as independent predictors of reduced OS. Notably, classical radiation-induced disease (cRILD) was absent, but nonclassical (nc) RILD occurred in 7.7% of patients. Regression analysis linked a mean EQD2α/ß3-8 dose to the liver (12.8-12.6) with a 10% likelihood of ncRILD. CONCLUSION: SBRT offers a compelling option for achieving high local control and promising survival outcomes in HCC. The study supports a radiation dose range of 61-73.1 Gy, coupled with a mean liver dose under 12.6-12.8 Gy as EQD2, to achieve favorable FFLP rates, with acceptable toxicity rates.

Voxel-based tumor dose correlates to complete pathologic necrosis after transarterial radioembolization for hepatocellular carcinoma.

PURPOSE: The transarterial radioembolization (TARE) dose is traditionally calculated using the single-compartment Medical Internal Radiation Dose (MIRD) formula. This study utilized voxel-based dosimetry to correlate tumor dose with explant pathology in order to identify dose thresholds that predicted response. METHODS: All patients with HCC treated with TARE using yttrium-90 [90Y] glass microspheres at a single institution between January 2015 - June 2023 who underwent liver transplantation were eligible. The [90Y] distribution and dose-volume histograms were determined using Simplicity90 (Mirada Medical, Oxford UK) with a Bremsstrahlung SPECT/CT. A complete response was assigned if explant pathology showed complete necrosis and the patient had not undergone additional treatments to the same tumor after TARE. Logistic regression and receiver operator characteristic (ROC) curves were constructed to evaluate dose thresholds correlated with response. RESULTS: Forty-one patients were included. Twenty-six (63%) met criteria for complete response. Dose to 95% (D95), 70% (D70), and 50% (D50) of the tumor volume were associated with likelihood of complete response by logistic regression (all p < 0.05). For lesions with complete response versus without, the median D95 was 813 versus 232 Gy, D70 was 1052 versus 315 Gy, and D50 was 1181 versus 369 Gy (all p < 0.01). A D95 > 719 Gy had the highest accuracy at 68% (58% sensitivity, 87% specificity) for predicting complete response. Median percent of tumor volume receiving at least 100 Gy (V100), 200 Gy (V200), 300 Gy (V300), and 400 Gy (V400) also differed by pathologic response: the median V100, V200, V300, and V400 was 100% versus 99%, 100% versus 97%, 100% versus 74%, and 100% versus 43% in the complete response versus non-complete response groups, respectively (all p < 0.05). CONCLUSION: Voxel-based dosimetry was well-correlated with explant pathology. The D95 threshold had the highest accuracy, suggesting the D95 may be a relevant target for multi-compartment dosimetry.

Adjuvant holmium-166 radioembolization after radiofrequency ablation in early-stage hepatocellular carcinoma patients: a dose-finding study (HORA EST HCC trial).

PURPOSE: The aim of this study was to investigate the biodistribution of (super-)selective trans-arterial radioembolization (TARE) with holmium-166 microspheres (166Ho-MS), when administered as adjuvant therapy after RFA of HCC 2-5 cm. The objective was to establish a treatment volume absorbed dose that results in an absorbed dose of ≥ 120 Gy on the hyperemic zone around the ablation necrosis (i.e., target volume). METHODS: In this multicenter, prospective dose-escalation study in BCLC early stage HCC patients with lesions 2-5 cm, RFA was followed by (super-)selective infusion of 166Ho-MS on day 5-10 after RFA. Dose distribution within the treatment volume was based on SPECT-CT. Cohorts of up to 10 patients were treated with an incremental dose (60 Gy, 90 Gy, 120 Gy) of 166Ho-MS to the treatment volume. The primary endpoint was to obtain a target volume dose of ≥ 120 Gy in 9/10 patients within a cohort. RESULTS: Twelve patients were treated (male 10; median age, 66.5 years (IQR, [64.3-71.7])) with a median tumor diameter of 2.7 cm (IQR, [2.1-4.0]). At a treatment volume absorbed dose of 90 Gy, the primary endpoint was met with a median absorbed target volume dose of 138 Gy (IQR, [127-145]). No local recurrences were found within 1-year follow-up. CONCLUSION: Adjuvant (super-)selective infusion of 166Ho-MS after RFA for the treatment of HCC can be administered safely at a dose of 90 Gy to the treatment volume while reaching a dose of ≥ 120 Gy to the target volume and may be a favorable adjuvant therapy for HCC lesions 2-5 cm. TRIAL REGISTRATION: Clinicaltrials.gov NCT03437382 . (registered: 19-02-2018).

90Y post-radioembolization clinical assessment with whole-body Biograph Vision Quadra PET/CT: image quality, tumor, liver and lung dosimetry.

PURPOSE: Evaluation of 90Y liver radioembolization post-treatment clinical data using a whole-body Biograph Vision Quadra PET/CT to investigate the potential of protocol optimization in terms of scan time and dosimetry. METHODS: 17 patients with hepatocellular carcinoma with median (IQR) injected activity 2393 (1348-3298) MBq were included. Pre-treatment dosimetry plan was based on 99mTc-MAA SPECT/CT with Simplicit90Y™ and post-treatment validation with Quadra using Simplicit90Y™ and HERMIA independently. Regarding the image analysis, mean and peak SNR, the coefficient of variation (COV) and lesion-to-background ratio (LBR) were evaluated. For the post-treatment dosimetry validation, the mean tumor, whole liver and lung absorbed dose evaluation was performed using Simplicit90Y and HERMES. Images were reconstructed with 20-, 15-, 10-, 5- and 1- min sinograms with 2, 4, 6 and 8 iterations. Wilcoxon signed rank test was used to show statistical significance (p < 0.05). RESULTS: There was no difference of statistical significance between 20- and 5- min reconstructed times for the peak SNR, COV and LBR. In addition, there was no difference of statistical significance between 20- and 1- min reconstructed times for all dosimetry metrics. Lung dosimetry showed consistently lower values than the expected. Tumor absorbed dose based on Simplicit90Y™ was similar to the expected while HERMES consistently underestimated significantly the measured tumor absorbed dose. Finally, there was no difference of statistical significance between expected and measured tumor, whole liver and lung dose for all reconstruction times. CONCLUSION: In this study we evaluated, in terms of image quality and dosimetry, whole-body PET clinical images of patients after having been treated with 90Y microspheres radioembolization for liver cancer. Compared to the 20-min standard scan, the simulated 5-min reconstructed images provided equal image peak SNR and noise behavior, while performing also similarly for post-treatment dosimetry of tumor, whole liver and lung absorbed doses.

Combined image-guided radiofrequency and iodine-125 seeds implantation in the treatment of recurrent hepatocellular carcinoma after hepatectomy.

BACKGROUND: Currently, there is no consensus on the treatment of recurrent hepatocellular carcinoma (HCC) after hepatectomy. It is necessary to assess the efficacy and safety of radiofrequency ablation (RFA) combined with iodine-125 seeds implantation (RFA-125I) in the treatment of recurrent HCC. METHODS: This study retrospectively analyzed the clinical data of patients with postoperative recurrence of HCC receiving RFA-125I or RFA treatment from January 2013 to January 2023. Both RFA and 125I seeds implantation were performed under dual guidance of ultrasound and CT. Overall survival (OS), progression-free survival (PFS), recurrence, and complications were compared between the two groups. RESULTS: A total of 210 patients with recurrent HCC were enrolled in this study, including 125 patients in the RFA-125I group and 85 patients in the RFA group. The RFA-125I group showed a significantly better survival benefit than RFA group (median OS: 37 months vs. 16 months, P < 0.001; median PFS: 15 months vs. 10 months, P = 0.001). The uni- and multivariate analysis showed that RFA-125I was a protective factor for OS and PFS. There were no procedure-related deaths and no grade 3 or higher adverse events in both groups. CONCLUSIONS: RFA combined with 125I seeds implantation under dual guidance of ultrasound and CT is effective and safe for the treatment of HCC patients with recurrence after hepatectomy.

A randomised controlled trial of Standard Of Care versus RadioAblaTion in Early Stage HepatoCellular Carcinoma (SOCRATES HCC).

BACKGROUND: Therapeutic options for early-stage hepatocellular carcinoma (HCC) in individual patients can be limited by tumor and location, liver dysfunction and comorbidities. Many patients with early-stage HCC do not receive curative-intent therapies. Stereotactic ablative body radiotherapy (SABR) has emerged as an effective, non-invasive HCC treatment option, however, randomized evidence for SABR in the first line setting is lacking. METHODS: Trans-Tasman Radiation Oncology Group (TROG) 21.07 SOCRATES-HCC is a phase II, prospective, randomised trial comparing SABR to other current standard of care therapies for patients with a solitary HCC ≤ 8 cm, ineligible for surgical resection or transplantation. The study is divided into 2 cohorts. Cohort 1 will compromise 118 patients with tumors ≤ 3 cm eligible for thermal ablation randomly assigned (1:1 ratio) to thermal ablation or SABR. Cohort 2 will comprise 100 patients with tumors > 3 cm up to 8 cm in size, or tumors ≤ 3 cm ineligible for thermal ablation, randomly assigned (1:1 ratio) to SABR or best other standard of care therapy including transarterial therapies. The primary objective is to determine whether SABR results in superior freedom from local progression (FFLP) at 2 years compared to thermal ablation in cohort 1 and compared to best standard of care therapy in cohort 2. Secondary endpoints include progression free survival, overall survival, adverse events, patient reported outcomes and health economic analyses. DISCUSSION: The SOCRATES-HCC study will provide the first randomized, multicentre evaluation of the efficacy, safety and cost effectiveness of SABR versus other standard of care therapies in the first line treatment of unresectable, early-stage HCC. It is a broad, multicentre collaboration between hepatology, interventional radiology and radiation oncology groups around Australia, coordinated by TROG Cancer Research. TRIAL REGISTRATION: anzctr.org.au, ACTRN12621001444875, registered 21 October 2021.