Adaptive design of experiments to fit surrogate Gaussian process regression models allows fast sensitivity analysis of the input waveform for patient-specific 3D CFD models of liver radioembolization.

BACKGROUND AND OBJECTIVE: Patient-specific 3D computational fluid dynamics (CFD) models are increasingly being used to understand and predict transarterial radioembolization procedures used for hepatocellular carcinoma treatment. While sensitivity analyses of these CFD models can help to determine the most impactful input parameters, such analyses are computationally costly. Therefore, we aim to use surrogate modelling to allow relatively cheap sensitivity analysis. As an example, we compute Sobol's sensitivity indices for three input waveform shape parameters. METHODS: We extracted three characteristic shape parameters from our input mass flow rate waveform (peak systolic mass flow rate, heart rate, systolic duration) and defined our 3D input parameter space by varying these parameters within 75 %-125 % of their nominal values. To fit our surrogate model with a minimal number of costly CFD simulations, we developed an adaptive design of experiments (ADOE) algorithm. The ADOE uses 100 Latin hypercube sampled points in 3D input space to define the initial design of experiments (DOE). Subsequently, we re-sample input space with 10,000 Latin Hypercube sampled points and cheaply estimate the outputs using the surrogate model. In each of 27 equivolume bins which divide our input space, we determine the most uncertain prediction of the 10,000 points, compute the true outputs using CFD, and add these points to the DOE. For each ADOE iteration, we calculate Sobol's sensitivity indices, and we continue to add batches of 27 samples to the DOE until the Sobol indices have stabilized. RESULTS: We tested our ADOE algorithm on the Ishigami function and showed that we can reliably obtain Sobol's indices with an absolute error <0.1. Applying ADOE to our waveform sensitivity problem, we found that the first-order sensitivity indices were 0.0550, 0.0191 and 0.407 for the peak systolic mass flow rate, heart rate, and the systolic duration, respectively. CONCLUSIONS: Although the current study was an illustrative case, the ADOE allows reliable sensitivity analysis with a limited number of complex model evaluations, and performs well even when the optimal DOE size is a priori unknown. This enables us to identify the highest-impact input parameters of our model, and other novel, costly models in the future.

Safety and Efficacy of 90Y Selective Internal Radiation Therapy Using Glass Microspheres in Hepatocellular Carcinoma: A Southeast Asian Single-Institution Initial Experience.

Our objective was to demonstrate primarily the safety and secondarily the efficacy of 90Y glass microspheres in selective internal radiation therapy (SIRT) for hepatocellular carcinoma (HCC) in a local Southeast Asian hospital. Methods: Eleven consecutive patients with small, unresectable, nonmetastatic HCC and referred for locoregional therapy with SIRT with a curative intention were followed up for 6 mo after the procedure by way of interviews, blood tests, and anatomic scans. Results: Although 5 patients had deranged liver function tests after the procedure, in only 1 patient did this constitute a grade 1 toxicity (in alkaline phosphatase) by the Common Terminology Criteria for Adverse Events. Half the patients showed a reduction in serum α-fetoprotein measurements, and 6 of 11 patients demonstrated an objective response (complete or partial) on imaging. Conclusion: SIRT with 90Y glass microspheres is a safe and efficacious locoregional therapy for unresectable HCC. There are similar articles published in the West; however, the patient population there comprises far fewer Asians and the underlying cause for HCC is different from that in the Asian population. Despite these differences, SIRT is an equally effective and safe option for such patients.

Microinvasion in hepatocellular carcinoma: predictive factor and application for definition of clinical target volume for radiotherapy.

BACKGROUND: To investigate the correlation between microinvasion and various features of hepatocellular carcinoma (HCC), and to clarify the microinvasion distance from visible HCC lesions to subclinical lesions, so as to provide clinical basis for the expandable boundary of clinical target volume (CTV) from gross tumor volume (GTV) in the radiotherapy of HCC. METHODS: HCC patients underwent hepatectomy of liver cancer in our hospital between July 2019 and November 2021 were enrolled. Data on various features and tumor microinvasion distance were collected. The distribution characteristics of microinvasion distance were analyzed to investigate its potential correlation with various features. Tumor size compared between radiographic and pathologic samples was analyzed to clarify the application of pathologic microinvasion to identify subclinical lesions of radiographic imaging. RESULTS: The average microinvasion distance was 0.6 mm, with 95% patients exhibiting microinvasion distance less than 3.0 mm, and the maximum microinvasion distance was 4.0 mm. A significant correlation was found between microinvasion and liver cirrhosis (P = 0.036), serum albumin level (P = 0.049). Multivariate logistic regression analysis revealed that HCC patients with cirrhosis had a significantly lower risk of microinvasion (OR = 0.09, 95%CI = 0.02 ~ 0.50, P = 0.006). Tumor size was overestimated by 1.6 mm (95%CI=-12.8 ~ 16.0 mm) on radiographic size compared to pathologic size, with a mean %Δsize of 2.96% (95%CI=-0.57%~6.50%). The %Δsize ranged from - 29.03% to 34.78%. CONCLUSIONS: CTV expanding by 5.4 mm from radiographic GTV could include all pathologic microinvasive lesions in the radiotherapy of HCC. Liver cirrhosis was correlated with microinvasion and were independent predictive factor of microinvasion in HCC.

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.

Outcomes of Y90 Radioembolization for Hepatocellular Carcinoma in Patients Previously Treated with Transarterial Embolization.

The aim of this study was to evaluate outcomes of transarterial radioembolization (TARE) for hepatocellular carcinoma (HCC) in patients previously treated with transarterial embolization (TAE). In this retrospective study, all HCC patients who received TARE from 1/2012 to 12/2022 for treatment of residual or recurrent disease after TAE were identified. Overall survival (OS) was estimated using the Kaplan-Meier method. Univariate Cox regression was performed to determine significant predictors of OS after TARE. Twenty-one patients (median age 73.4 years, 18 male, 3 female) were included. Median dose to the perfused liver volume was 121 Gy (112-444, range), and 18/21 (85.7%) patients received 112-140 Gy. Median OS from time of HCC diagnosis was 32.9 months (19.4-61.4, 95% CI). Median OS after first TAE was 29.3 months (15.3-58.9, 95% CI). Median OS after first TARE was 10.6 months (6.8-27.0, 95% CI). ECOG performance status of 0 (p = 0.038), index tumor diameter < 4 cm (p = 0.022), and hepatic tumor burden < 25% (p = 0.018) were significant predictors of longer OS after TARE. TARE may provide a survival benefit for appropriately selected patients with HCC who have been previously treated with TAE.

Image-guided percutaneous strategies to improve the resectability of HCC: Portal vein embolization, liver venous deprivation, or radiation lobectomy?

Despite considerable advances in surgical technique, many patients with hepatic malignancies are not operative candidates due to projected inadequate hepatic function following resection. Consequently, the size of the future liver remnant (FLR) is an essential consideration when predicting a patient's likelihood of liver insufficiency following hepatectomy. Since its initial description 30 years ago, portal vein embolization has become the standard of care for augmenting the size and function of the FLR preoperatively. However, new minimally invasive techniques have been developed to improve surgical candidacy, chief among them liver venous deprivation and radiation lobectomy. The purpose of this review is to discuss the status of preoperative liver augmentation prior to resection of hepatocellular carcinoma with a focus on these three techniques, highlighting the distinctions between them and suggesting directions for future investigation.

Effect of cytokines on advanced hepatocellular carcinoma prognosis receiving radiotherapy and tislelizumab plus anlotinib: a single-center phase II clinical trial.

The purpose of this study was to investigate the relationship between circulating cytokines and liver function and prognosis of patients with advanced hepatocellular carcinoma (HCC) treated with radiotherapy combined with tislelizumab and anlotinib. The liver function indexes and pre-treatment levels of cytokines in 47 patients were measured by chemical method and flow cytometry. The median follow-up was 23.1 months. The objective response and the disease control rates were 46.8% and 68.1%, while overall survival (OS) and progression-free survival (PFS) were 12.6 and 11.4 months, respectively. Adverse events (2.1%) were grade 3-4. In addition to stage, intrahepatic metastasis and Child-Pugh score, pre-treatment interleukin-6 (IL-6) was the main cytokine affecting OS and PFS (p < 0.05). The OS (14.63 pg/mL as cutoff value) and PFS (9.85 pg/mL as cutoff value) of patients with low IL-6 levels exceeded those with high levels (21.0 and 6.9, 15.8 and 10.0 months, respectively). The risks of death and disease progression were reduced by 63.0% (HR = 0.37, 95% CI: 0.19-0.72) and 43.0% (HR = 0.57, 95% CI: 0.22-1.47), respectively. Pre-treatment IL-6 levels may be a simple and effective prognostic indicator for patients with advanced HCC treated with radiotherapy combined with immunotargeted therapy.

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.

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.

Selective internal radiation therapy segmentectomy: A new minimally invasive curative option for primary liver malignancies?

Transarterial radioembolization or selective internal radiation therapy (SIRT) has emerged as a minimally invasive approach for the treatment of tumors. This percutaneous technique involves the local, intra-arterial delivery of radioactive microspheres directly into the tumor. Historically employed as a palliative measure for liver malignancies, SIRT has gained traction over the past decade as a potential curative option, mirroring the increasing role of radiation segmentectomy. The latest update of the BCLC hepatocellular carcinoma guidelines recognizes SIRT as an effective treatment modality comparable to other local ablative methods, particularly well-suited for patients where surgical resection or ablation is not feasible. Radiation segmentectomy is a more selective approach, aiming to deliver high-dose radiation to one to three specific hepatic segments, while minimizing damage to surrounding healthy tissue. Future research efforts in radiation segmentectomy should prioritize optimizing radiation dosimetry and refining the technique for super-selective administration of radiospheres within the designated hepatic segments.

Long-term outcome of adjuvant radiotherapy upon postoperative relapse of centrally located hepatocellular carcinoma: a real-world study.

Despite that surgical resection is widely regarded as the most effective approach to the treatment of liver cancer, its safety and efficacy upon centrally located hepatocellular carcinoma (HCC) remain unsatisfactory. In consequence, seeking an integrated treatment, like combined with adjuvant radiotherapy, to enhance the prognosis of patients is of critical importance. By recruiting patients undergoing surgical resection for centrally located HCC ranging from June 2015 to 2020, they were divided into liver resection combined with adjuvant radiotherapy (LR + RT) and mere liver resection (LR) groups. The calculation of propensity score and model of Cox proportional hazards regression were utilized. 193 patients were recruited in aggregation, containing 88 ones undergoing LR + RT, while 105 handled with LR. RT was verified to be an independent factor of prognosis for relapse (HR 0.60). In propensity-score analyses, significant association existed between adjuvant radiotherapy and better disease-free survival (DFS) (Matched, HR 0.60; Adjustment of propensity score, HR 0.60; Inverse probability weighting, HR 0.63). The difference of DFS was apparent within two groups (p value = 0.022), and RT significantly down-regulated early relapse (p value < 0.05) in subgroup analysis. The calculation of E-value revealed robustness of unmeasured confounding. The combination of liver surgical resection with RT is safe and effective towards patients with centrally located HCC, which would notably enhance the prognosis and decrease the early relapse of HCC.

Proton Beam Radiotherapy as a Curative Alternative to Radiofrequency Ablation for Newly Diagnosed Hepatocellular Carcinoma.

BACKGROUND/AIM: This study aimed to compare the oncological outcomes of proton beam radiotherapy (PBT) with those of radiofrequency ablation (RFA) for newly diagnosed hepatocellular carcinoma (HCC). PATIENTS AND METHODS: This study included 323 patients who underwent PBT (n=40) or RFA (n=283) as a curative treatment for previously untreated HCC between October 2016 and June 2021. The primary endpoints were local progression and toxicity. RESULTS: The median follow-up was 3.4 years (range=1.1-5.7 years). In terms of portal vein tumor thrombosis, tumor size, alpha-fetoprotein, and prothrombin-induced by vitamin K absence-II, the PBT group had significantly more severe tumor burdens than those of the RFA group (p<0.0001, p<0.0001, p=0.0004, and p<0.0001, respectively). No significant difference was observed in cumulative local progression rate (10.4% in PBT vs. 7.8% in RFA at 3-years, p=0.895). Grade 3 or higher toxicity was reported in only one patient (0.4%) after RFA. Multivariable analysis demonstrated that treatment modality was not a significant prognostic factor for local progression (hazard ratio=1.05; 95% confidence interval=0.32-3.48; p=0.934). CONCLUSION: PBT demonstrated comparable local control with acceptable toxicity to RFA in newly diagnosed HCC. Therefore, PBT may be a valid alternative.

Prognostic analysis of radiation-induced liver damage following carbon-ion radiotherapy for hepatocellular carcinoma.

BACKGROUND: Radiation-induced liver damage (RILD) occasionally occurs following carbon-ion radiotherapy (CIRT) for liver tumors, such as hepatocellular carcinoma (HCC), in patients with impaired liver function disease. However, the associated risk factors remain unknown. The present study aimed to determine the risk factors of RILD after CIRT. METHODS: We retrospectively analyzed 108 patients with HCC treated with CIRT at the Osaka Heavy Ion Therapy Center between December 2018 and December 2022. RILD was defined as a worsening of two or more points in the Child-Pugh score within 12 months following CIRT. The median age of the patients was 76 years (range 47-95 years), and the median tumor diameter was 41 mm (range 5-160 mm). Based on the pretreatment liver function, 98 and 10 patients were categorized as Child-Pugh class A and B, respectively. We analyzed patients who received a radiation dose of 60 Gy (relative biological effectiveness [RBE]) in four fractions. The median follow-up period was 9.7 months (range 2.3-41.1 months), and RILD was observed in 11 patients (10.1%). RESULTS: Multivariate analysis showed that pretreatment Child-Pugh score B (p = 0.003, hazard ratio [HR] = 6.90) and normal liver volume spared from < 30 Gy RBE (VS30 < 739 cm3) (p = 0.009, HR = 5.22) were significant risk factors for RILD. The one-year cumulative incidences of RILD stratified by Child-Pugh class A or B and VS30 < 739 cm3 or ≥ 739 cm3 were 10.3% or 51.8% and 39.6% or 9.2%, respectively. CONCLUSION: In conclusion, the pretreatment Child-Pugh score and VS30 of the liver are significant risk factors for RILD following CIRT for HCC.

Quetiapine Significantly Improves the Effectiveness of Radiotherapy in Combating Hepatocellular Carcinoma Progression in a Hep3B Xenograft Mouse Model.

BACKGROUND/AIM: In hepatocellular carcinoma (HCC) treatment, radiotherapy (RT) stands as a pivotal approach, yet the emergence of radioresistance poses a formidable challenge. This study aimed to explore the potential synergy between quetiapine and RT for HCC treatment. MATERIALS AND METHODS: A Hep3B xenograft mouse model was used, the investigation tracked tumor progression, safety parameters, and molecular mechanisms. RESULTS: The findings revealed a synergistic anti-HCC effect when quetiapine was coupled with RT that prolonged tumor growth time and a significantly higher growth inhibition rate compared to the control group. Safety assessments indicated minimal pathological changes, suggesting potential of quetiapine in mitigating RT-induced alterations in liver and kidney functions. Mechanistically, the combination suppressed metastasis and angiogenesis-related proteins, while triggering the activation of apoptosis-related proteins via targeting Epidermal growth factor receptor (EGFR)-mediated signaling. CONCLUSION: The potential of the quetiapine and RT combination is emphasized, offering enhanced anti-HCC efficacy, a safety profile, and positioning quetiapine as a radiosensitizer for HCC treatment.

Radionuclide Therapy With 177 Lu-PSMA in a Patient With Hepatocellular Carcinoma.

ABSTRACT: A 69-year-old man diagnosed with progressive bone metastatic castration-resistant prostate adenocarcinoma and concurrent alcoholic cirrhosis with multiple hepatocellular carcinoma (HCC) nodules was referred to our nuclear medicine service for 177 Lu-PSMA-617 therapy. The patient's pretreatment screening using 68 Ga-PSMA-11 PET/CT revealed high prostate-specific membrane antigen expression in both prostatic and HCC lesions. The patient underwent 2 doses of 177 Lu-PSMA-617. Subsequent imaging assessments with 68 Ga-PSMA-11 PET/CT and hepatic MRI indicated progressive HCC nodules, while showing a partial response in prostatic bone metastases. Positive clinical and biological responses were observed only in prostatic disease, but not in HCC nodules.

TLR3 activation enhances abscopal effect of radiotherapy in HCC by promoting tumor ferroptosis.

Radiotherapy (RT) has been reported to induce abscopal effect in advanced hepatocellular carcinoma (HCC), but such phenomenon was only observed in sporadic cases. Here, we demonstrated that subcutaneous administration of Toll-like receptor 3 (TLR3) agonist poly(I:C) could strengthen the abscopal effect during RT through activating tumor cell ferroptosis signals in bilateral HCC subcutaneous tumor mouse models, which could be significantly abolished by TLR3 knock-out or ferroptosis inhibitor ferrostatin-1. Moreover, poly(I:C) could promote the presentation of tumor neoantigens by dendritic cells to enhance the recruitment of activated CD8+ T cells into distant tumor tissues for inducing tumor cell ferroptosis during RT treatment. Finally, the safety and feasibility of combining poly(I:C) with RT for treating advanced HCC patients were further verified in a prospective clinical trial. Thus, enhancing TLR3 signaling activation during RT could provide a novel strategy for strengthening abscopal effect to improve the clinical benefits of advanced HCC patients.

Persistent Fatigue in Patients With Hepatocellular Carcinoma Receiving Radiotherapy.

BACKGROUND: Radiation therapy has attracted much attention in the treatment of patients with hepatocellular carcinoma (HCC). However, the association between radiotherapy-related fatigue and HCC has been examined in only a few studies. PURPOSE: This study was designed to explore the change over time in fatigue in patients with HCC treated with radiotherapy and related factors. METHODS: One hundred patients were enrolled in this prospective longitudinal study using convenience sampling at a medical center in northern Taiwan. The Functional Assessment of Chronic Illness Therapy-Fatigue scale, the Brief Pain Inventory-Short Form, and the psychological subscale of Memorial Symptom Assessment Scale-Short Form were used to assess the symptoms at five time points: before radiotherapy (T0), during treatment (T1), and at 1 month (T2), 3 months (T3), and 6 months (T4) after radiotherapy. The generalized estimating equations method was used to determine the changes in fatigue and the influencing factors. RESULTS: Fatigue levels at T1, T2, T3, and T4 were significantly higher than that at T0. Higher fatigue was significantly associated with lower income and poorer functional status. Having worse pain levels and psychological symptoms were both associated with higher fatigue. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: The results indicate fatigue does not recover to the baseline (pretherapy) level by 6 months after radiotherapy. Thus, fatigue in patients with HCC receiving radiotherapy should be regularly and effectively assessed, and patients experiencing pain and psychological symptoms should be given greater attention from clinicians.