Single-Session Ablative Transarterial Radioembolization for Patients with Hepatocellular Carcinoma to Streamline Care: An Initial Experience.

PURPOSE: Transarterial radioembolization (TARE) for hepatocellular carcinoma (HCC) is performed after a mapping angiogram involving infusion of radiolabeled macroaggregated albumin to assess for non-target embolization and pulmonary shunting. The purpose of this case series was to evaluate the safety and feasibility of single-session TARE without the initial procedure. MATERIALS AND METHODS: A single-institution case series of 16 consecutive procedures on 15 patients with 18 tumors who underwent an attempted single-session TARE procedures with glass microspheres are presented. A lung shunt fraction (LSF) of 5% was assumed for planning purposes. RESULTS: Sixty-seven percent (10/15) of patients were male with a median age of 72 years. Median tumor size was 2.5 cm (IQR 2.0-3.2 cm). Sixteen of the 18 targeted tumors were untreated prior to the single-session TARE. Rate of technical success was 88% (14/16). Two patients did not ultimately receive a single-session TARE due to intraprocedural findings. The mean administered activity was 2.0 GBq, and the mean MIRD dose was 464 Gy based on pre-treatment anatomic imaging and 800 Gy based on cone-beam CT. There were no cases of radiation pneumonitis. Mean post-procedural calculated lung dose was 4.9 Gy (range 3.1-9.3) based on SPECT. CONCLUSIONS: An initial experience with single-session TARE using Y-90 glass microspheres without pre-procedural mapping angiography and lung shunt estimation demonstrates that it is a feasible and safe treatment option for select patients with small (< 5 cm) HCC. LEVEL OF EVIDENCE IV: Level 4 case series.

Thymic Carcinoma Presenting as a Mediastinal Mass Resembling a Cardiac Tumor.

Thymoma and thymic carcinomas are a few of the rarest malignancies seen in humankind. They are mostly seen in the Asian population, many of which are reported in the Southeast Asia region like Japan, China, Vietnam, etc. They usually can be a sequela of other underlying conditions such as myasthenia gravis or some unknown mutations that express later in life.   Our patient is a young 41-year-male, a healthy and active individual who presented for evaluation of acute shortness of breath, two months after recovering from SARS-CoV-19 infection. His shortness of breath progressed while on oxygen and diuretics, a Point of Care Ultrasound (POCUS) showed cardiac tamponade and moderate pleural effusion. A Computerized Tomographic (CT) scan of the chest/abdomen/pelvis showed cardiomegaly, pleural effusion, and a mass abutting the heart. A pericardiocentesis revealed malignant cells. Thymic carcinoma was confirmed with a core biopsy and the patient was initiated on treatment rapidly to help improve symptoms and contain the growing mass.  .

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 Holmium-166 selective internal radiotherapy of primary and secondary liver cancer confirmed by real-world data.

Purpose: Holmium-166 has emerged as a promising option for selective internal radiotherapy (SIRT) for hepatic malignancies, but data on routine clinical use are lacking. The purpose of this study was to describe the safety and effectiveness of Holmium-166 SIRT in real-world practice through retrospective analysis of a multicenter registry. Methods: Retrospective analysis was conducted on Holmium-166 SIRT procedures performed between July 15, 2019, and July 15, 2021, across seven European centers. Treatment planning, treatment realization and post-treatment follow-up were conducted according to routine local practice. Safety and effectiveness data were extracted from the patients' health records. Primary endpoint analysis was assessed for the entire study population with separate analysis for subgroups with hepatocellular carcinoma, metastatic colorectal cancer and intrahepatic cholangiocarcinoma. Results: A total of 167 SIRT procedures in 146 patients (mean age 66 ± 11 years, 68% male) were retrospectively evaluated. Most common tumor entities were hepatocellular carcinoma (n=55), metastatic colorectal cancer (n=35), intrahepatic cholangiocarcinoma (n=19) and metastatic neuroendocrine tumors (n=10). Nine adverse events grade ≥ 3 according to Common Terminology Criteria for Adverse Events were recorded, including one fatal case of radioembolization-induced liver disease. Response rates and median overall survival for the above mentioned subgroups were comparable to results from previous Holmium-166 trials as well as to results from Yttrium-90 registries. Conclusion: This study confirms that the safety and effectiveness of Holmium-166 SIRT derived from prospective trials also applies in routine clinical practice, reinforcing its potential as a viable treatment option for primary and secondary liver cancer.

Ultrastable PLGA-Coated 177Lu-Microspheres for Radioembolization Therapy of Hepatocellular Carcinoma.

Transarterial radioembolization (TARE) is a highly effective localized radionuclide therapy that has been successfully used to treat hepatocellular carcinoma (HCC). Extensive research has been conducted on the use of radioactive microspheres (MSs) in TARE, and the development of ideal radioactive MSs is crucial for clinical trials and patient treatment. This study presents the development of a radioactive MS for TARE of HCC. These MSs, referred to as 177Lu-MS@PLGA, consist of poly(lactic-co-glycolic acid) (PLGA) copolymer and radioactive silica MSs, labeled with 177Lu and then coated with PLGA. It has an extremely high level of radiostability. Cellular experiments have shown that it can cause DNA double-strand breaks, leading to cell death. In vivo radiostability of 177Lu-MS@PLGA is demonstrated by microSPECT/CT imaging. In addition, the antitumor study has shown that TARE of 177Lu-MS@PLGA can effectively restrain tumor growth without harmful side effects. Thus, 177Lu-MS@PLGA exhibits significant potential as a radioactive MS for the treatment of HCC.

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.

Prognostic Value of Liver Biomarkers in Hepatocellular Carcinoma Patients Undergoing Yttrium 90 Transarterial Radioembolization (TARE): A Retrospective Pilot Study.

INTRODUCTION: Hepatocellular carcinoma (HCC) is a common cause of cancer-related death worldwide. The prognosis for HCC depends on the tumor stage, and curative therapies are more accessible in the early stages. However, effective treatments are available even in advanced stages. Transarterial radioembolization (TARE) is an alternative to transarterial chemoembolization (TACE) with reduced risk and extended disease progression time. Identifying prognostic indicators and treatment response biomarkers remains crucial. The purpose of this study was to assess the association between biomarkers related to fibrosis, liver function, and immune inflammation with tumor response to yttrium 90 transarterial radiotherapy (Y90 or TARE) in patients with HCC. METHODS: This study enrolled patients who underwent Y90 radiotherapy for bridging, downstaging, or palliative treatment after discussion in a multidisciplinary tumor board. Using the modified Response Evaluation Criteria in Solid Tumors (mRECIST), tumor response was classified into two groups: "responders" (complete and partial response) and "non-responders" (stable and progressive disease). Logistic regression analysis was used to evaluate the association between predictors, biomarkers such as aspartate aminotransferase (AST)-to-platelet ratio index (APRI), fibrosis-4 (FIB-4), albumin-bilirubin (ALBI) score, model for end-stage liver disease (MELD) score, MELD sodium, and the systemic immune-inflammatory indexes, at established cut-offs and tumor response. RESULTS: Of 35 patients, 22 (63%) were Whites and non-Hispanics, 32 (91%) were diagnosed with cirrhosis, and 14 (40%) of these had a viral etiology. According to mRECIST, 18 (51%) patients were classified as "responders." In multivariable logistic regression analysis, biomarkers associated with tumor response were ALBI score ≤-2.8 (odds ratio (OR) 6.1, 95%CI 2.7-14.4) and the neutrophil-to-lymphocyte ratio (NLR) ≤ 1.92 (OR 5.1, 95%CI 0.8-11.9). Biomarkers had moderate accuracy in predicting tumor response (C-statistic 0.75). CONCLUSION: The ALBI score is a reliable predictor of treatment response following TARE. The NLR index may offer further prognostic information, and both biomarkers can be used in combination; however, further research in larger sample sets is needed.

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.

Contralateral Hypertrophy Post Yttrium-90 Transarterial Radioembolization in Patients With Hepatocellular Carcinoma and Portal Vein Tumor Thrombus.

Objectives Contralateral hypertrophy of non-irradiated liver following Yttrium-90 (90Y) transarterial radioembolization (TARE) is increasingly recognized as an option to facilitate curative surgical resection in patients that would otherwise not be surgical candidates due to a small future liver remnant (FLR). This study aimed to investigate the correlation between patient features and liver hypertrophy and identify potential predictors for liver growth in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT) undergoing TARE. Methodology Twenty-three patients with HCC and PVTT were included. Contralateral liver hypertrophy was assessed at six months posttreatment based on CT or MRI imaging. Thirteen patient features were selected for statistical and prediction analysis. Univariate Spearman correlation and analysis of variance (ANOVA) tests were performed. Subsequently, four feature-selection methods based on multivariate analysis were used to improve model generalization performance. The selected features were applied to train linear regression models, with fivefold cross-validation to assess the performance of the predicted models. Results The ratio of disease-free target liver volume to spared liver volume and total liver volume showed the highest correlations with contralateral hypertrophy (P-values = 0.03 and 0.05, respectively). In three out of four feature-selection methods, the feature of disease-free target liver volume to total liver volume ratio was selected, having positive correlations with the outcome and suggesting that more hypertrophy may be expected when more volume of disease-free liver is irradiated. Conclusions Contralateral hypertrophy post-90Y TARE can be an option for facilitating surgical resection in patients with otherwise small FLR.

The Apparent Diffusion Coefficient of the Paraspinal and Psoas Muscles Are of Prognostic Relevance in Patients With Hepatocellular Carcinoma Undergoing Transarterial Radioembolization.

Background/Aim: Transarterial radioembolization (TARE) is a treatment option for early or intermediate stage hepatocellular carcinoma (HCC). Sarcopenia is defined as loss of muscle strength and quality which can be estimated by imaging modalities and has been associated with prognosis and treatment response in HCC patients. Apparent diffusion coefficient (ADC) values derived from diffusion-weighted imaging (DWI) can reflect the tissue composition and might be better to determine muscle changes of sarcopenia than the standard method of computed tomography (CT). The present study sought to elucidate ADC values of the abdominal wall muscles as a prognostic factor in patients undergoing TARE. Patients and Methods: A retrospective analysis was performed between 2016 and 2020. Overall, 52 patients, 9 women (17.3%) and 43 men (82.7%), with a mean age of 69±8.5 years were included into the analysis. In every case, the first pre-interventional magnetic resonance imaging (MRI) including DWI was used to measure the ADC values of paraspinal and psoas muscle. The 12-month survival after TARE was used as the primary study outcome. Results: Overall, 40 patients (76.9%) of the patient cohort died within the 12-month observation period. Mean overall survival was 10.9 months after TARE for all patients. Mean ADC values for all muscles were 1.31±0.13×10-3mm2/s. The ADC values of the paraspinal muscles were statistically significantly higher compared to the ADC values of the psoas muscles (p=0.0031). A positive correlation was identified between mean ADC and the thrombocyte count (r=0.37, p=0.005) and serum bilirubin (r=-0.30, p=0.03). In the multivariate Cox regression analysis, the mean ADC values of all muscles were associated with the survival after 12 months (HR=0.98, 95% CI=0.97-0.99, p=0.04). Conclusion: ADC values of the abdominal wall muscles could be used as a prognostic biomarker in patients with HCC undergoing TARE. These preliminary results should be confirmed by further studies using external validation cohorts and other treatment modalities.

Use of dose-volume histograms for metabolic response prediction in hepatocellular carcinoma patients undergoing transarterial radioembolization with Y-90 resin microspheres.

INTRODUCTION: Voxel-based dosimetry offers improved outcomes in the treatment of hepatocellular carcinoma (HCC) with transarterial radioembolization (TARE) using glass microspheres. However, the adaptation of voxel-based dosimetry to resin-based microspheres has been poorly studied, and the prognostic relevance of heterogeneous dose distribution remains unclear. This study aims to explore the use of dose-volume histograms for resin microspheres and to determine thresholds for objective metabolic response in HCC patients treated with resin-based TARE. METHODS: We retrospectively reviewed HCC patients who underwent TARE with Y-90-loaded resin microspheres in our institution between January 2021 and December 2022. Voxel-based dosimetry was performed on post-treatment Y-90 PET/CT images to extract parameters including mean dose absorbed by the tumor (mTD), the percentage of the targeted tumor volume (pTV), and the minimum doses absorbed by consecutive percentages within the tumor volume (D10, D25, D50, D75, D90). Assessment of metabolic response was done according to PERCIST criteria with F-18 FDG PET/CT imaging at 8-12 weeks after the treatment. RESULTS: This study included 35 lesions targeted with 22 TARE sessions in 19 patients (15 males, 4 females, mean age 60 ± 13 years). Objective metabolic response was achieved in 43% of the lesions (n = 15). Responsive lesions had significantly higher mTD, pTV, and D25-D90 values (all p < 0.05). Optimal cut-off values for mTD, pTV, and D50 were 94.6 Gy (sensitivity 73%, specificity 70%, AUC 0.72), 94% (sensitivity 73%, specificity 55%, AUC 0.64), and 91 Gy (sensitivity 80%, specificity 80%, AUC 0.80), respectively. CONCLUSION: Parameters derived from dose-volume histograms could offer valuable insights for predicting objective metabolic response in HCC patients treated with resin-based TARE. If verified with larger prospective cohorts, these parameters could enhance the precision of dose distribution and potentially optimize treatment outcomes.

Impact of scatter correction on personalized dosimetry in selective internal radiotherapy using 166Ho-PLLA: a single-center study including Monte-Carlo simulation, phantom and patient imaging.

BACKGROUND: Developments in transarterial radioembolization led to the conception of new microspheres loaded with holmium-166 (166Ho). However, due to the complexity of the scatter components in 166Ho single photon emission computed tomography (SPECT), questions about image quality and dosimetry are emerging. The aims of this work are to investigate the scatter components and correction methods to propose a suitable solution, and to evaluate the impact on image quality and dosimetry including Monte-Carlo (MC) simulations, phantom, and patient data. METHODS: Dual energy window (DEW) and triple energy window (TEW) methods were investigated for scatter correction purposes and compared using Contrast Recovery Coefficients (CRC) and Contrast to Noise Ratios (CNR). First, MC simulations were carried out to assess all the scatter components in the energy windows used, also to confirm the choice of the parameter needed for the DEW method. Then, MC simulations of acquisitions of a Jaszczak phantom were conducted with conditions mimicking an ideal scatter correction. These simulated projections can be reconstructed and compared with real acquisitions corrected by both methods and then reconstructed. Finally, both methods were applied on patient data and their impact on personalized dosimetry was evaluated. RESULTS: MC simulations confirmed the use of k = 1 for the DEW method. These simulations also confirmed the complexity of scatter components in the main energy window used with a high energy gamma rays component of about half of the total counts detected, together with a negligible X rays component and a negligible presence of fluorescence. CRC and CNR analyses, realized on simulated scatter-free projections of the phantom and on scatter corrected acquisitions of the same phantom, suggested an increased efficiency of the TEW method, even at the price of higher level of noise. Finally, these methods, applied on patient data, showed significant differences in terms of non-tumoral liver absorbed dose, non-tumoral liver fraction under 50 Gy, tumor absorbed dose, and tumor fraction above 150 Gy. CONCLUSIONS: This study demonstrated the impact of scatter correction on personalized dosimetry on patient data. The use of a TEW method is proposed for scatter correction in 166Ho SPECT imaging.

Outcome of transarterial radioembolization in patients with hepatocellular carcinoma as a first-line interventional therapy and after a previous transarterial chemoembolization.

Purpose: Due to a lack of data, there is an ongoing debate regarding the optimal frontline interventional therapy for unresectable hepatocellular carcinoma (HCC). The aim of the study is to compare the results of transarterial radioembolization (TARE) as the first-line therapy and as a subsequent therapy following prior transarterial chemoembolization (TACE) in these patients. Methods: A total of 83 patients were evaluated, with 38 patients having undergone at least one TACE session prior to TARE [27 male; mean age 67.2 years; 68.4% stage Barcelona clinic liver cancer (BCLC) B, 31.6% BCLC C]; 45 patients underwent primary TARE (33 male; mean age 69.9 years; 40% BCLC B, 58% BCLC C). Clinical [age, gender, BCLC stage, activity in gigabecquerel (GBq), Child-Pugh status, portal vein thrombosis, tumor volume] and procedural [overall survival (OS), local tumor control (LTC), and progression-free survival (PFS)] data were compared. A regression analysis was performed to evaluate OS, LTC, and PFS. Results: No differences were found in OS (95% CI: 1.12, P = 0.289), LTC (95% CI: 0.003, P = 0.95), and PFS (95% CI: 0.4, P = 0.525). The regression analysis revealed a relationship between Child-Pugh score (P = 0.005), size of HCC lesions (>10 cm) (P = 0.022), and OS; neither prior TACE (Child-Pugh B patients; 95% CI: 0.120, P = 0.729) nor number of lesions (>10; 95% CI: 2.930, P = 0.087) correlated with OS. Conclusion: Prior TACE does not affect the outcome of TARE in unresectable HCC.

Extrahepatic 90Y Complication; Gastric Ulcer Secondary to 90Y Therapy for Liver Metastasis Despite Negative Preprocedural Imaging.

Transarterial radioembolization using yttrium-90 (90Y) therapy has become a standard modality of treatment for primary and metastatic liver malignancies due to its high efficacy rate and relatively low risk of adverse effects compared to other forms of locoregional and systemic therapies. Non-target distribution of radio embolic beads and adjacent structure radiation are the two most common adverse effects. However, these are rarely encountered due to thorough imaging and mapping studies prior to 90Y therapy. We present the case of a 66-year-old male who developed a radiation-induced gastric ulcer following 90Y therapy with negative pre-procedural imaging and mapping who was retrospectively found to have an accessory artery from the left hepatic artery to the gastric antrum.

The Influence of Additional Treatments on the Survival of Patients Undergoing Transarterial Radioembolization (TARE).

The aim of this study was to present our preliminary experience with transarterial radioembolization (TARE) using Yttrium-90 (90Y), compare the cancer-specific survival (CSS) of patients with hepatocellular carcinoma (HCC) and colorectal cancer (CRC) liver metastases undergoing TARE, and investigate the influence of additional treatments on CSS. Our database was interrogated to retrieve patients who had undergone TARE using Yttrium-90 (90Y) glass or resin microspheres. Kaplan-Meier curves and the log-rank test were employed to conduct survival analysis for the different groups (p < 0.05). Thirty-nine patients were retrieved (sex: 27 M, 12 F; mean age: 63.59 ± 15.66 years): twenty-three with hepatocellular carcinoma (HCC) and sixteen with CRC liver metastasis. Globally, the patients with HCC demonstrated a significantly longer CSS than those with CRC liver metastasis (22.64 ± 2.7 vs. 7.21 ± 1.65 months; p = 0.014). Among the patients with CRC liver metastasis, those receiving TARE and additional concomitant treatments (n = 10) demonstrated a longer CSS than the CRC patients receiving only TARE (9.97 ± 2.21 vs. 2.59 ± 0.24 months; p = 0.06). In the HCC group, there was a trend of a longer CSS in patients (n = 8) receiving TARE and additional treatments (27.89 ± 3.1 vs. 17.69 ± 3.14 months; p = 0.15). Patients with HCC seem to achieve a longer survival after TARE compared to patients with CRC liver metastases. In patients with CRC liver metastases, the combination of TARE and additional concomitant treatments may improve survival.

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.

Factors Impacting Survival After Transarterial Radioembolization in Patients with Unresectable Intrahepatic Cholangiocarcinoma: A Combined Analysis of the Prospective CIRT Studies.

PURPOSE: Transarterial radioembolization (TARE) with Yttrium-90 resin microspheres is a treatment option for patients with intrahepatic cholangiocarcinoma (ICC). However, optimising the timing of TARE in relation to systemic therapies and patient selection remains challenging. We report here on the effectiveness, safety, and prognostic factors associated with TARE for ICC in a combined analysis of the prospective observational CIRT studies (NCT02305459 and NCT03256994). METHODS: A combined analysis of 174 unresectable ICC patients enrolled between 2015 and 2020 was performed. Patient characteristics and treatment-related data were collected at baseline; adverse events and time-to-event data (overall survival [OS], progression-free survival [PFS] and hepatic PFS) were collected at every follow-up visit. Log-rank tests and a multivariable Cox proportional hazard model were used to identify prognostic factors. RESULTS: Patients receiving a first-line strategy of TARE in addition to any systemic treatment had a median OS and PFS of 32.5 months and 11.3 months. Patients selected for first-line TARE alone showed a median OS and PFS of 16.2 months and 7.4 months, whereas TARE as 2nd or further treatment-line resulted in a median OS and PFS of 12 and 9.3 months (p = 0.0028), and 5.1 and 3.5 months (p = 0.0012), respectively. Partition model dosimetry was an independent predictor for better OS (HR 0.59 [95% CI 0.37-0.94], p = 0.0259). No extrahepatic disease, no ascites, and < 6.1 months from diagnosis to treatment were independent predictors for longer PFS. CONCLUSION: This combined analysis indicates that in unresectable ICC, TARE in combination with any systemic treatment is a promising treatment option. LEVEL OF EVIDENCE: level 3, Prospective observational.

Radiomics Features Extracted From Pre- and Postprocedural Imaging in Early Prediction of Treatment Response in Patients Undergoing Transarterial Radioembolization of Hepatic Lesions: A Systematic Review, Meta-Analysis, and Quality Appraisal Study.

INTRODUCTION: Transarterial radioembolization (TARE) is one of the most promising therapeutic options for hepatic masses. Radiomics features, which are quantitative numeric features extracted from medical images, are considered to have potential in predicting treatment response in TARE. This article aims to provide meta-analytic evidence and critically appraise the methodology of radiomics studies published in this regard. METHODS: A systematic search was performed on PubMed, Scopus, Embase, and Web of Science. All relevant articles were retrieved, and the characteristics of the studies were extracted. The Radiomics Quality Score and Checklist for Evaluation of Radiomics Research were used to assess the methodologic quality of the studies. Pooled sensitivity, specificity, and area under the receiver operating characteristic curve in predicting objective response were determined. RESULTS: The systematic review included 15 studies. The average Radiomics Quality Score of these studies was 11.4 ± 2.1, and the average Checklist for Evaluation of Radiomics Research score was 33± 6.7. There was a notable correlation (correlation coefficient = 0.73) between the two metrics. Adherence to quality measures differed considerably among the studies and even within different components of the same studies. The pooled sensitivity and specificity of the radiomics models in predicting complete or partial response were 83.5% (95% confidence interval 76%-88.9%) and 86.7% (95% confidence interval 78%-92%), respectively. CONCLUSION: Radiomics models show great potential in predicting treatment response in TARE of hepatic lesions. However, the heterogeneity seen between the methodologic quality of studies may limit the generalizability of the results. Future initiatives should aim to develop radiomics signatures using multiple external datasets and adhere to quality measures in radiomics methodology.

Impact of Low Muscle Mass on Hepatocellular Carcinoma Patients Undergoing Transcatheter Liver-Directed Therapies: Systematic Review & Meta-Analysis.

BACKGROUND AND AIM: Transcatheter liver-directed intra-arterial therapies are mainstream treatment options for intermediate-stage hepatocellular carcinoma (HCC). However, the effect of low skeletal muscle mass (LSMM) on overall survival (OS) in these patients remains uncertain. We aimed to ascertain the prevalence and prognostic effect of LSMM in this population. METHOD: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a comprehensive search was performed in the PubMed and Embase databases until Oct 2023. Random-effects meta-analysis was performed to determine the pooled prevalence of LSMM and calculate the hazard ratio (HR) for OS with a 95% confidence interval (CI) in patients with intermediate-stage HCC undergoing various transarterial therapies, comparing those with and without LSMM. RESULTS: Twelve studies involving 2450 patients were included. The pooled prevalence of LSMM was 46% (95% CI, 38-55%), and the results were consistent across different treatments, regions, and age subgroups. The meta-analysis indicated that LSMM was significantly associated with decreased OS (HR, 1.78; 95% CI, 1.36-2.33; I2, 75%). Subgroup analyses reassured the main findings across various therapies, including transarterial chemoembolization (TACE) (HR, 1.68; 95% CI, 1.23-2.30; I2, 81%), transarterial embolization (TAE) (HR, 2.45; 95% CI, 1.42-4.22; I2, 0%), and transarterial radioembolization (TARE) (HR, 1.94; 95% CI, 1.01-3.73; I2, 0%). CONCLUSIONS: In intermediate-stage HCC, LSMM is common and associated with reduced OS. To achieve an optimal prognosis, clinicians should incorporate routine LSMM measurement into practice, while caring for patients with intermediate-stage HCC, irrespective of TACE, TAE, and TARE.