Resin Microspheres Research Articles

Polymer composite microspheres loading 177Lu radionuclide for interventional radioembolization therapy and real-time SPECT imaging of hepatic cancer

BackgroundTransarterial radioembolization (TARE) with 90Y-labeled glass and resin microspheres is one of the primary treatment strategies for advanced-stage primary and metastatic hepatocellular carcinoma (HCC). However, difficulties of real-time monitoring post administration and embolic hypoxia influence treatment prognosis. In this study, we developed a new biodegradable polymer microsphere that can simultaneously load 177Lu and MgO nanoparticle, and evaluated the TARE therapeutic efficacy and biosafety of 177Lu-PDA-CS-MgO microspheres for HCC treatment.MethodsChitosan microspheres were synthesized through emulsification crosslink reaction and then conducted surface modification with polydopamine (PDA). The 177Lu and nano MgO were conjugated to microspheres using active chemical groups of PDA. The characteristics of radionuclide loading efficiency, biodegradability, blood compatibility, and anti-tumor effectwere evaluated both in vitro and in vivo. SPECT/CT imaging was performed to monitor bio-distribution and bio-stability of 177Lu-PDA-CS-MgO after TARE treatment. The survival duration of each rat was monitored. HE analysis, TUNEL analysis, immunohistochemical analysis, and western blot analysis were conducted to explore the anti-tumor effect and mechanism of composited microspheres. Body weight, liver function, blood routine examination were monitored at different time points to evaluate the bio-safety of microspheres.ResultsThe composite 177Lu-PDA-CS-MgO microsphere indicated satisfactory degradability, biocompatibility, radionuclide loading efficiency and radiochemical stability in vitro. Cellular evaluation showed that 177Lu-PDA-CS-MgO had significant anti-tumor effect and blocked tumor cell cycles in S phase. Surgical TARE treatment with 177Lu-PDA-CS-MgO significantly prolonged the medial survival time from 49 d to 105 d, and effectively inhibited primary tumor growth and small metastases spreading. Moreover, these microspheres indicated ideal in vivo stability and allowed real-time SPECT/CT monitoring for up to 8 weeks. Immunostaining and immunoblotting results also confirmed that 177Lu-PDA-CS-MgO had potential in suppressing tumor invasion and angiogenesis, and improved embolic hypoxia in HCC tissues. Further evaluations of body weight, blood test, and pathological analysis indicated good biosafety of 177Lu-PDA-CS-MgO microspheres in vivo.ConclusionOur study demonstrated that 177Lu-PDA-CS-MgO microsphere hold great potential as interventional brachytherapy candidate for HCC therapy.Graphical Polymer composite microspheres loading 177Lu radionuclide and MgO nanoparticles for interventional radioembolization therapy and real-time SPECT imaging of hepatic cancer.

Spherical activated carbons derived from resin-microspheres for the adsorption of acetic acid

Separation of small-molecule carboxylic acids, especially acetic acid, from wastewater is challenging due to its high-water solubility, acidity, and low concentration. In this work, resin-derived spherical activated carbon (RSAC) was directly prepared from resin spheres through facile pre-oxidation and carbonization processes. RSAC was characterized by SEM, N2 physisorption, XRD, Raman, element analysis and XPS. RSAC showed high removal rates (> 95.8 %) for a variety of small-molecule carboxylic acids. The initial adsorption capacity of acetic acid over RSAC was 23.4 mg/g and 94 % of the removal rate was retained after five successive adsorption-desorption cycles for 1000 mg/L acetic acid. In addition, RSAC showed a high total organic carbon removal rate (> 80 %) for the high-salinity effluent of catalytic wet air oxidation (CWAO) process. The adsorption of acetic acid over RSAC complied with the pseudo-second-order model and Langmuir model ideally, through Vander Waals force and pore-filling effect. Furtherly, discarded resin microspheres were used to prepare spherical active carbon, which showed 88.2 % removal of acetic acid (1000 mg/L). The benign scheme of “treating wastes by wastes” from economical and environmental aspects was realized.

Yttrium-90 Radioembolization as the Major Treatment of Hepatocellular Carcinoma.

The purpose of this study was to assess the safety and efficacy of Yttrium-90 radioembolization using in unresectable hepatocellular carcinoma. From 2017 to 2021, 32 patients with unresectable hepatocellular carcinoma, with mean tumor diameter about 7cm (21 males, 11 females; median age, 57.5 years of age), treated with Yttrium-90 radioembolization using resin microspheres were reviewed at pre-Yttrium-90 and post-Yttrium-90 follow-up. Tumor response was assessed according to the modified Response Evaluation Criteria in Solid Tumors. Outcomes including overall survival and progression-free survival were reported. Median follow-up was 18 months. At follow-up examinations at 3-, 6-, and 12-months follow-up, the overall survival rates were 94%, 87% and 59%, and the progression-free survival rates were 78%, 64% and 60%, respectively. Complete response, partial response, stable disease, and progressive disease were noted in 7 (21.9%), 14 (43.7%), 4 (12.5%), and 7 (21.9%) patients, respectively. The disease control rate was 78.1%, the objective response rate was 65.6%, and the successful downstage rate was 34.4% (11 of 32). Nine of thirty-two patients underwent resection or transplantation after Yttrium-90 radioembolization with 2-year overall survival being 100%. No serious adverse events occurred after Yttrium-90 treatment. Worse overall survival was related to the larger tumor, higher stage, Eastern Cooperative Oncology Group performance status, and Child-Pugh score. And worse progression-free survival was related to the higher tumor burden, and pre-Yttrium-90 serum α-fetoprotein level >100. Yttrium-90 Radioembolization can control hepatocellular carcinoma well even in advanced diseases. Patients successfully downstaging/bridging to resection or transplantation have excellent overall survival.

Phase I prospective trial of TAS-102 (trifluridine and tipiracil) and radioembolization with 90Y resin microspheres for chemo-refractory colorectal liver metastases

BackgroundExtrahepatic disease progression limits clinical efficacy of Yttrium-90 (90Y) radioembolization (TARE) for patients with chemotherapy-refractory metastatic colorectal cancer (mCRC). Trifluridine and tipiracil (TAS-102) has overall survival benefit for patients with refractory mCRC and may be a radiosensitizer.MethodsSequential lobar TARE using 90Y resin microspheres in combination with TAS-102 in 28-day cycles were used to treat adult patients with bilobar liver-dominant chemo-refractory mCRC according to 3 + 3 dose escalation design with a 12-patient dose expansion cohort. Study objectives were to establish safety and determine maximum tolerated dose (MTD) of TAS-102 in combination with TARE.ResultsA total of 21 patients (14 women, 7 men) with median age of 60 years were enrolled. No dose limiting toxicities were observed. Treatment related severe adverse events included cytopenias (10 patients, 48%) and radioembolization-induced liver disease (2 patients, 10%). Disease control rate in the liver lobes treated with TARE was 100%. Best observed radiographic responses were partial response for 4 patients (19%) and stable disease for 12 patients (57%).ConclusionsThe combination of TAS-102 and TARE for patients with liver-dominant mCRC is safe and consistently achieves disease control within the liver.Trial registrationClinicalTrials.gov identifier NCT02602327 (first posted 11/11/2015).

How the Rigid and Deformable Image Registration Approaches Affect the Absorbed Dose Estimation Using Images Collected before and after Transarterial Radioembolization with 90Y Resin Microspheres in a Clinical Setting

Background: Transarterial radioembolization (TARE) relies on directly injected 90Y- or 166Ho-loaded microspheres in the hepatic arteries. The activity to be injected is generally based on pre-TARE 99mTc-macro-aggregated-albumin (MAA) imaging, while the actual dose distribution is based on post-treatment images. The volume of interest (VOIs) propagation methods (i.e., rigid and deformable) from pre- to post-TARE imaging might affect the estimation of the mean absorbed dose in the tumor and non-tumoral liver (NTL), i.e., DT and DNTL, respectively. Methods: In 101 consecutive patients, liver and tumor were delineated on pre-TARE images and semi-automatically transferred on 90Y-PET/CT images with a rigid or deformable registration approach. Pre- and post-TARE volumes and DT/DNTL/DL were compared using correlation coefficient (CC) indexes, such as intra-class (ICC), Pearson’s (PCC), concordance (CCCo) and Bland–Altman analyses. The Kaplan–Meier curves of overall survival (OS) were calculated according to DT. Results: All computed CCs indicated very good (>0.92) agreement for volume comparison, while they suggested good (ICC ≥ 0.869, PCC ≥ 0.876 and CCCo ≥ 0.790) and moderate agreement in the intra- and inter-modality DT/DNTL/DL comparisons, respectively. Bland–Altman analyses showed percentage differences between the manual and deformable approaches of up to about −31%, 9% and 62% for tumoral volumes, DT and DNTL, respectively. The overall survival analysis showed statistically significant differences using DT cutoffs of 110, 90 and 85 Gy for the manual, rigid and deformable approaches, respectively. Conclusions: The semi-automatic transfer of VOIs from pre- and post-TARE imaging is feasible, but the selected method might affect prognostic DT/DNTL constraints.

Survival and Toxicities after Yttrium-90 Transarterial Radioembolization of Cholangiocarcinoma in the RESiN Registry

PurposeTo report outcomes in patients with intrahepatic cholangiocarcinoma treated with yttrium-90 resin microspheres (transarterial radioembolization [TARE]) from a multicenter, prospective observational registry. Materials and MethodsNinety-five patients (median age, 67 years [interquartile range {IQR}, 59–74]; 50 men) were treated in 27 centers between July 2015 and August 2020. Baseline demographic characteristics included imaging findings, performance status, and previous systemic or locoregional treatments. Dosimetry method was tracked. Overall survival (OS) and progression-free survival were calculated using the Kaplan-Meier method. The best imaging response was calculated using the Response Evaluation Criteria in Solid Tumors v1.1. Grade ≥3 toxicities were assessed using Common Terminology Criteria for Adverse Events v5. Cox regression analysis was performed. ResultsFifty-two of 86 (60%) patients had multifocal tumors, and 24/89 (27%) had extrahepatic tumors. The median index tumor diameter was 7.0 cm (IQR, 4.9–10 cm). The activity calculation method was reported in 59/95 (62%) patients, with body surface area being the most frequently used method (45/59, 76%). Median OS for the cohort was 14 months (95% confidence interval, 12–22). OS at 3, 6, 12, and 24 months was 94%, 80%, 63%, and 34%, respectively. Median OS was longer in patients without cirrhosis (19.1 vs 12.2 months, P = .05). Cirrhosis, previous chemotherapy (OS, 19.1 vs 10.6 months for treatment-naïve; P = .07), and imaging response at 6 months (OS, 16.4 vs 9.5 months for no response; P = .06) underwent regression analysis. Imaging response predicted OS at regression (hazard ratio, 0.39; P = .008). Grade 3–4 bilirubin toxicities were noted in 5 of 72 (7%) patients. Grade 3 albumin toxicity was noted in 1 of 72 (1.4%) patients. ConclusionsObjective response at 6 months predicted longer OS after TARE for intrahepatic cholangiocarcinoma. The incidence of liver function toxicity was <10%.

Temporary Reversal of Hepatoenteric Collaterals during 90Y Radioembolization Planning and Administration

This paper aims to evaluate the safety and efficacy of the temporary redirection of blood flow of hepatoenteric collaterals using a balloon catheter in the common hepatic artery (CHA) to prevent the nontarget deposition of 90Y microspheres. In this retrospective single-center study of patients who received 90Y radioembolization (RE) from September 2010 to September 2015, diagnostic (67 patients) or treatment (72 patients) angiograms with the attempted use of a balloon catheter in the CHA to temporarily direct blood flow away from the hepatoenteric arteries were analyzed. SPECT/CT nuclear scintigraphy was performed after both diagnosis and treatment. Overall, only 12 hepatoenteric arteries in 11 patients required embolization due to persistent hepatoenteric flow despite the use of the balloon occlusion technique in a total of 86 patients. Physicians performed the 90Y RE using balloon occlusion with glass (n = 22) or resin (n = 50) microspheres. Over 80% administration of the prescribed 90Y dose was accomplished in 34 (67%) resin and 20 (95%) glass microsphere patients. Post-treatment 90Y RE scintigraphy confirmed the absence of extrahepatic activity in all patients. One grade 2 gastrointestinal ulcer was present after 90 days of follow-up. Temporary CHA occlusion with a balloon catheter is a reliable and reproducible alternative to the conventional coil embolization of hepatoenteric arteries during diagnostic Tc-99m macroaggregated albumin and therapeutic 90Y RE delivery.

PD32 Cost-Utility Of Selective Internal Radiation Therapy Using Y-90 Resin Microspheres For Chemotherapy-Refractory Metastatic Colorectal Cancer In Brazil

IntroductionThere were an estimated 55,102 new cases of colorectal cancer (CRC) in Brazil in 2020, comprising 9.3 percent of all newly diagnosed cancers, and making it the third most common cancer in the Brazilian population. Up to half of all patients with CRC will develop liver metastases, and the prognosis for these patients is poor. The objective of the present analysis was to evaluate the cost-utility of selective internal radiation therapy (SIRT) using Y-90 resin microspheres versus best supportive care (BSC) in patients with unresectable, liver-dominant, chemotherapy-refractory metastatic CRC (mCRC).MethodsA three-state partitioned survival model was developed in Microsoft Excel to evaluate the cost-utility of SIRT using Y-90 resin microspheres versus BSC. Membership of the three model states of pre-progression, post-progression and death was governed by parametric models of Kaplan-Meier data from a retrospective, interventional study. Costs associated with SIRT using Y-90 resin microspheres, BSC, and adverse events were obtained from Brazilian sources and reported in 2021 United States dollars (USD). Future costs and effects were discounted at 5 percent. One-way and probabilistic sensitivity analyses (PSA) were performed. A willingness-to-pay threshold of USD 53,936 was used based on a 2017 review of Brazilian healthcare technology adoption.ResultsThe base case analysis showed that Y-90 resin microspheres would result in an increase of 0.76 QALYs versus BSC, increasing quality-adjusted life expectancy from 0.67 QALYs to 1.43 QALYs. The improvement in quality-adjusted life expectancy was accompanied by an increase in costs from USD 9,884 to USD 40,399 over the model time horizon, corresponding to an increase of USD 30,515, and yielding an incremental cost-utility ratio (ICUR) of USD 40,265 per QALY gained. PSA showed there was a 90.8 percent likelihood of cost-effectiveness at USD 53,936 per QALY gained.ConclusionsSIRT using Y-90 resin microspheres was cost-effective versus BSC in the treatment of unresectable, liver-dominant mCRC patients and should be considered for incorporation in the Brazilian Private Healthcare System.

PD28 Cost-Effectiveness Of Selective Internal Radiation Therapy Using Y-90 Resin Microspheres For Unresectable Hepatocellular Carcinoma In Brazil

IntroductionHepatocellular cancer (HCC) is a severe condition with poor prognosis and a significant burden. Selective internal radiation therapy (SIRT) is recommended as an alternative treatment option to overcome some limitations of current treatments. This analysis estimated the cost-effectiveness of SIRT using Y-90 resin microspheres for the treatment of unresectable HCC in Brazil.MethodsThis study was conducted from the Brazilian payer perspective according to local guidelines, with a lifetime horizon. The use of SIRT in patients with intermediate- or advanced-stage HCC, without extrahepatic disease and ineligible to transarterial chemoembolization, was compared with sorafenib, the commonly used HCC systemic treatment in Brazil. A sensitivity analysis included the subgroup of patients with low tumour burden and preserved liver function.A partitioned-survival model was developed, which included a tunnel state for patients downstaged to receive a treatment with a curative intent such as liver surgery, transplantation or ablation. Survival curves, utilities and adverse events incidence were extracted from published sources of pivotal randomized control trials. Effectiveness of health interventions was measured in quality-adjusted-life-years (QALYs) and life-years (LYs). Local costs from Brazil were applied. Future costs and effects were discounted at five percent. A willingness-to-pay threshold of USD 53,936 was used, based on a 2017 review of healthcare technology adoption in Brazil.ResultsLYs and QALYs were higher for SIRT using Y-90 resin microspheres versus sorafenib (0.27 and 0.20 incremental LYs and QALYs, respectively) and costs were slightly higher for SIRT (USD 3,056 incremental costs). The incremental cost-effectiveness ratio (ICER) was USD 14,948 per QALY in the basecase.One-way and probabilistic sensitivity analyses confirmed the robustness of the analyses. Scenario analyses tested different model assumptions and reinforced the basecase results indicating that SIRT using Y-90 resin microspheres was highly likely to be cost-effective compared with sorafenib. Also, the ICER was lower in the subgroup compared with the overall population.ConclusionsSIRT using Y-90 resin microspheres represents a cost-effective option compared with sorafenib in Brazil.

EE191 A Budget Impact Analysis of Selective Internal Radiation Therapy Using Y-90 Resin Microspheres Versus Atezolizumab-Bevacizumab as First-Line Therapy in Barcelona Clinic Liver Cancer Stage C Hepatocellular Carcinoma in England

EE191 A Budget Impact Analysis of Selective Internal Radiation Therapy Using Y-90 Resin Microspheres Versus Atezolizumab-Bevacizumab as First-Line Therapy in Barcelona Clinic Liver Cancer Stage C Hepatocellular Carcinoma in England

Factors impacting survival after transarterial radioembolization in patients with hepatocellular carcinoma: Results from the prospective CIRT study

Transarterial radioembolization (TARE) with Yttrium-90 resin microspheres is an established treatment option for patients with hepatocellular carcinoma (HCC). However, optimising treatment application and patient selection remains challenging. We report here on the effectiveness, safety and prognostic factors, including dosing methods, associated with TARE for HCC in the prospective observational CIRT study. We analysed 422 patients with HCC enrolled between Jan 2015 and Dec 2017, with follow-up visits every 3 months for up to 24 months after first TARE. 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 3-month follow-up visit. We used the multivariable Cox proportional hazard model and propensity score matching to identify independent prognostic factors for effectiveness outcomes. The median OS was 16.5 months, the median PFS was 6.1 months, and the median hepatic PFS was 6.7 months. Partition model dosimetry resulted in improved OS compared to body surface area calculations on multivariable analysis (hazard ratio 0.65; 95% CI 0.46-0.92; p= 0.0144), which was confirmed in the exact matching propensity score analysis (hazard ratio 0.56; 95% CI 0.35-0.89; p= 0.0136). Other independent prognostic factors for OS were ECOG-performance status >0 (p= 0.0018), presence of ascites (p= 0.0152), right-sided tumours (p= 0.0002), the presence of portal vein thrombosis (p= 0.0378) and main portal vein thrombosis (p= 0.0028), ALBI grade 2 (p= 0.0043) and 3 (p= 0.0014). Adverse events were recorded in 36.7% of patients, with 9.7% of patients experiencing grade 3 or higher adverse events. This large prospective observational dataset shows that TARE is an effective and safe treatment in patients with HCC. Using partition model dosimetry was associated with a significant improvement in survival outcomes. Transarterial radioembolization (TARE) is a form of localised radiation therapy and is a potential treatment option for primary liver cancer. We observed how TARE was used in real-life clinical practice in various European countries and if any factors predict how well the treatment performs. We found that when a more complex but personalised method to calculate the applied radiation activity was used, the patient responded better than when a more generic method was used. Furthermore, we identified that general patient health, ascites and liver function can predict outcomes after TARE. NCT02305459.

Synthesis of octavinyl polyhedral oligomeric silsesquioxane (ovi‐POSS) based organic/inorganic hybrid resin microspheres for rapid and efficient oils absorption

AbstractIn this work, a hybrid nanocomposite of poly(styrene‐co‐butyl acrylate‐co‐dodecyl acrylate) and octavinyl polyhedral oligomeric silsesquioxane (ovi‐POSS) was synthesized by suspension polymerization and the composite resin was characterized by Fourier transform infrared, scanning electron microscopy energy‐dispersive spectrometer and thermal gravimetric analysis. The effects of ovi‐POSS content on the oil absorbency of hybrid composite resin were investigated. The results indicated that the maximum saturated oil absorption rate of sample PSBLA/ovi‐POSS‐1 with 1 wt% ovi‐POSS content toward four oils and organic solvents (toluene, xylene, gasoline, and diesel) are, respectively, 20.51, 18.56, 12.48, and 7.03 g g−1, and the process taken just about 5 min. The absorption kinetic model fitting proved that the adsorption behavior of the four oils on PSBLA/ovi‐POSS‐1 resin microspheres was dominated by the physical adsorption. Besides, PSBLA/ovi‐POSS‐1 has good oil retention rate (stay over 95% after centrifuging at 3000 rpm for 5 min) and reusability (for 12 times). These excellent oil absorption performances are attributed to the loose network structure of the composite resin. The rapid and efficient oils absorption properties give the composite resin potential practical applications in many areas.

A Chelating Resin of EDTA-Type Modified Cross-Linking Polystyrene to Preconcentrate Trace Metals for Seawater Detection.

The determination of trace metals in seawater is an important project of marine environmental monitoring. However, the presence of many alkali metal ions with high concentration, such as sodium ion, seriously interferes with the detection limit and accuracy of atomic absorption spectrometry (AAS, flame/graphite furnace integrated). The conventional chemical methods for the enrichment of trace metals are complex, and low boiling point organic solvents are used. In this paper, a kind of commercial cross-linked polystyrene resin microspheres was chloromethylated and aminated to introduce EDTA-type amino polycarboxylic groups and then loaded in a column as the absorption filler. A set of seawater pretreatment and enrichment devices was designed and assembled. The enriching process and conditions of trace Cu, Zn, Pb, and Cd in standard seawater were studied. 10 g of the modified resin could enrich the equivalent seawater and remove successfully the light metal ions. pH = 5∼9 and 0.2 mL/min of the flow rate were the suitable conditions for preconcentration. The enriched metal ions in the eluent were analyzed on the AAS. Compared with the conventional solvent method, the novel material and enrichment device have high preconcentration efficiency, strong anti-interference ability, and low cost and could be directly applied for routine seawater detection.

PET/CT calibration for post-treatment standard body scan acquisition with yttrium-90 resin micro-SPHERES

IntroductionAmong the objectives in treatments with yttrium-90 spheres, is to demonstrate that the tumoricidal dose is achieved and that hepatotoxic doses are avoided, as well as that there is no extrahepatic deposition. Material and methodsWe use different amounts of yttrium-90 resin micro-spheres and a NEMA NU2-2007 phantom to check if the scanner maintains a response that allows real dosimetric calculations. ResultsThe Gemini tomograph responds linearly in a wide range of activities with R2 = 0.9983. ConclusionThe detection capacity of the PET equipment allows us to carry out standard body studies with dosimetric purposes with times of five minutes per bed. It also make possible to verify the absence of extrahepatic deposition of significant amounts of yttrium 90 spheres.

Prognostic Factors for Effectiveness Outcomes After Transarterial Radioembolization in Metastatic Colorectal Cancer: Results From the Multicentre Observational Study CIRT

BackgroundTransarterial radioembolisation (TARE) with Yttrium-90 resin microspheres is a treatment option for patients with metastatic colorectal cancer in the liver (mCRC). A better understanding of the prognostic factors and treatment application can improve survival outcomes. MethodsWe analysed the safety and effectiveness of 237 mCRC patients included in the prospective observational study CIRSE Registry for SIR-Spheres Therapy (CIRT) for independent prognostic factors for overall survival (OS), progression-free survival (PFS) and hepatic progression-free survival (hPFS) using the Cox proportional-hazard model. ResultsThe median OS was 9.8 months, median PFS was 3.4 months and median hPFS was 4.2 months. Independent prognostic factors for an improved overall survival were the absence of extra-hepatic disease (P= .0391), prior locoregional procedures (P= .0037), an Aspartate transaminase to Platelet Ratio Index (APRI) value of ≤0.40 (P< .0001) and International Normalized Ratio (INR) ≤1 (P= .0078). Partition model dosimetry resulted in improved OS outcomes compared to the body surface area model (P = .0120). Independent predictors for PFS were APRI >0.40 (P = .0416) and prior ablation (P = .0323), and for hPFS these were 2 to 5 tumor nodules (P = .0148), Albumin-bilirubin (ALBI) grade 3 (P = .0075) and APRI >0.40 (P = .0207). During the study, 95 of 237 (40.1%) patients experienced 197 adverse events, with 28 of 237 (11.8%) patients having a grade 3 or higher adverse events. ConclusionIncluding easy-to-acquire laboratory markers INR, APRI, ALBI and using partition model dosimetry can identify mCRC patients that may benefit from TARE.

Radiation dose aspects and establishment of diagnostic reference levels for 90Y radioembolisation during angiographic procedure

90Y radioembolisation (RE) is an angiographic procedure used in patients with both primary and secondary hepatic malignancies. Local tumour control can be achieved by short range tumour irradiation by the regional intra-arterial administration of glass or resin microspheres loaded with 90yttrium that accumulate in the tumorous tissue. The aim of this study was to investigate the radiation exposure of RE and to establish a local diagnostic reference level (DRL). In this retrospective study, dose data from 397 procedures in 306 patients (mean age 67.4 ± 10.6 years, 82 female) who underwent RE between 06/2017 and 01/2022 using one of two different angiography systems were analysed. DRL was set as the 75th percentile of the dose distribution. In the overall population, dose area product (DAP) (median (interquartile range, IQR)) was 26 Gy cm2 (IQR 12–50) with a median fluoroscopy time (FT) of 4.5 min (IQR 2.9–8.0). FT and DAP increased significantly with the number of infusion positions (median, IQR): one position 23 Gy cm2 (12–46), two positions 33 Gy cm2 (14–60), three positions 50 Gy cm2 (24–82) (p < 0.0001). Local DRL is 47 Gy cm2 for RE and 111 Gy cm2 for RE with additional embolisation. Radiation exposure and FT are significantly higher with increasing number of infusion positions as well as additional embolisation. Our established DRLs for RE may serve as a benchmark for dose optimisation.

The Radiation Dose Absorbed by Healthy Parenchyma Is a Predictor for the Rate of Contralateral Hypertrophy After Unilobar Radioembolization of the Right Liver.

To investigate the predictors of contralateral hypertrophy in patients treated with unilobar transarterial radioembolization (TARE) with yttrium-90-loaded resin microspheres due to unresectable right-liver tumors. Patients who underwent right unilobar TARE with resin microspheres between May 2019 and September 2021 were screened retrospectively. Contralateral hypertrophy was evaluated by calculating the kinetic growth rate (KGR) in 8-10 weeks after TARE. The predictors of increased KGR were determined with linear regression analysis. A total of 24 patients (16 with primary and 8 with metastatic liver tumors) were included in the study. After right unilobar TARE, mean volume of the left lobe increased from 368.26 to 436.16 mL, while the mean volume of the right lobe decreased from 1576.22 to 1477.89 mL. The median KGR of the left lobe was 0.28% per week. The radiation dose absorbed by the healthy parenchyma of the right lobe was significantly higher in patients with increased KGR (31.62 vs. 18.78 Gy, p = 0.037). Linear regression analysis showed that the dose absorbed by healthy parenchyma was significantly associated with increased KGR (b = 0.014, p = 0.043). Patients who received right unilobar TARE for liver malignancies could develop a substantial contralateral hypertrophy, and the radiation dose absorbed by the healthy parenchyma of the right lobe was significantly associated with increased KGR in the left lobe. TARE could have a role for inducing contralateral hypertrophy as it offers the advantage of concurrent local tumor control along with its hypertrophic effect.

Trans-arterial Radioembolization Dosimetry in 2022.

Trans-arterial radioembolization is currently performed using 90Y-loaded glass or resin microspheres and also using 166Ho-loaded microspheres. The goal of this review is to present dosimetry and radiobiology concepts, the different dosimetry approaches available (simulation-based dosimetry and post-treatment dosimetry), main confounding factors as main clinical dosimetry results provided during the last decade for both hepatocellular carcinoma (HCC) and metastases of colorectal carcinoma (mCRC). Based on the different number of microspheres or different isotope used, radiobiology of the three devices is different, meaning that tumouricidal doses and maximal tolerated doses are different. Tumouricidal doses described for HCCs were 100-120 grays (Gy) with 90Y resin microspheres and 205Gy with 90Y glass microspheres. For mCRC, it is 39-60 with 90Y resin microspheres, 139Gy with 90Y glass microspheres and 90Gy with 166Ho microspheres. An impact of tumoural doses with overall survival has also been reported. Personalised dosimetry has been developed and is now recommended by several international expert groups. Level-one evidence of the major impact of personalised dosimetry on response and overall survival in HCC is now available, bringing a new standard approach for TARE in clinical practice as well as for trial design.

Outcomes following transarterial radioembolization with 90Y and nanoparticles loaded resin microspheres

90Y bremsstrahlung Single-Photon Emission Tomography (SPECT) imaging is employed to check the possibility of extrahepatic uptake and the quantification of delivered dose in Transarterial Radioembolization (TARE). 90Y bremsstrahlung SPECT imaging is challenging due to the nature of bremsstrahlung photons. We reported a Monte Carlo study using the resin microspheres loaded with 90Y and Nanoparticles (NPs) in the TARE. By injection of Bismuth (Bi) and Europium (Eu) NPs into the resin microspheres, the sensitivity and the contrast to noise ratio increased for the bremsstrahlung planar images. The highest signal to background ratio was observed in the characteristic X-ray planar images taken with the energy window at the Kα1 ± 10 keV when Eu NPs were incorporated into the microsphere. The dose enhancement ratio decreased dramatically at NP concentrations >2.4 M. Incorporating NPs into the resin microspheres improves the quality of post-treatment images and establishes a standardized imaging protocol for post-treatment imaging by characteristic X-rays.

Porous carbon microspheres with controlled porosity and graphitization degree for high-performance supercapacitor

• Porous carbon microspheres are synthesized via a simple template-free method. • Porous structure and graphitization degree are controlled. • Ni-based salts and ethanolamine affect porous structure and graphitization degree. • Porous carbon microspheres exhibited excellent supercapacitor performance. The fabrication of porous carbons plays an important role in improving electrochemical performance for supercapacitors. The fabrication of carbon microspheres with controlled porous structure and graphitization degree is still a challenge in synthetic methodology, since it is difficult to achieve both goals at the same time. Porous carbon microspheres with controlled porous structure and graphitization degree are realized here via a simple template-free method, using Ni-based salts and resorcinol-formaldehyde resin microspheres as raw materials. The amount and types of Ni-based salts as well as ethanolamine significantly affect the porous structure and graphitization degree for the carbon microspheres. The porous carbon microspheres prepared with 4.0 g of Ni(CH 3 COO) 2 ·4H 2 O and 0.25 mL of ethanolamine possess the surface area of 392.1 m 2 g −1 , the pore volume of 0.395 cm 3 g −1 and the I G /I D ratio of 1.18. The as-synthesized porous carbon microspheres can serve as excellent candidates for electrode materials in supercapacitors to achieve excellent electrochemical behaviors. The as-prepared porous carbon microspheres exhibit a specific capacitance of 193.8F g −1 at 1 A g −1 , good rate capability and long cycle life in a two-electrode system. The superior electrochemical performance can be attributed to both the unique hierarchical porous structure and high graphitization degree. The hierarchical porous structure can provide fine transportation pathways and a large number of adsorption sites for electrolyte ions, and high graphitization degree can ensure rapid electron transport.