Radioembolization Research Articles

Abstract No. 543 90Y Selective Internal Radiation Therapy for Ocular Melanoma Metastatic to the Liver: Dosimetry and Response Assessment

Abstract No. 543 90Y Selective Internal Radiation Therapy for Ocular Melanoma Metastatic to the Liver: Dosimetry and Response Assessment

Dosimetric impact of 3D motion-compensated SPECT reconstruction for SIRT planning

BackgroundIn selective internal radiation therapy, 99mTc SPECT images are used to optimize patient treatment planning, but they are affected by respiratory motion. In this study, we evaluated on patient data the dosimetric impact of motion-compensated SPECT reconstruction on several volumes of interest (VOI), on the tumor-to-normal liver (TN) ratio and on the activity to be injected.MethodsTwenty-nine patients with liver cancer or hepatic metastases treated by radioembolization were included in this study. The biodistribution of 90Y is assumed to be the same as that of 99mTc when predictive dosimetry is implemented. A total of 31 99mTc SPECT images were acquired and reconstructed with two methods: conventional OSEM (3D) and motion-compensated OSEM (3Dcomp). Seven VOI (liver, lungs, tumors, perfused liver, hepatic reserve, healthy perfused liver and healthy liver) were delineated on the CT or obtained by thresholding SPECT images followed by Boolean operations. Absorbed doses were calculated for each reconstruction using Monte Carlo simulations. Percentages of dose difference (PDD) between 3Dcomp and 3D reconstructions were estimated as well as the relative differences for TN ratio and activities to be injected. The amplitude of movement was determined with local rigid registration of the liver between the 3Dcomp reconstructions of the extreme phases of breathing.ResultsThe mean amplitude of the liver was 9.5 ± 2.7 mm. Medians of PDD were closed to zero for all VOI except for lungs (6.4%) which means that the motion compensation overestimates the absorbed dose to the lungs compared to the 3D reconstruction. The smallest lesions had higher PDD than the largest ones. Between 3D and 3Dcomp reconstructions, means of differences in lung dose and TN ratio were not statistically significant, but in some cases these differences exceed 1 Gy (4/31) and 8% (2/31). The absolute differences in activity were on average 3.1% ± 5.1% and can reach 22.8%.ConclusionThe correction of respiratory motion mainly impacts the lung and tumor doses but only for some patients. The largest dose differences are observed for the smallest lesions.

Downstaging locally advanced hepatocellular carcinoma with selective internal radiation therapy.

536 Background: Locally advanced HCC (beyond BCLC A, including PVT but without extra-hepatic metastases) that are unresectable because of inadequate future liver remnant may be downstaged by selective internal radiation therapy (SIRT) with Yttrium-90 to subsequently receive interval surgical resection. We hypothesized that HCC that required downstaging before resection will have some disparity in overall survival (OS) and recurrence-free survival (RFS) compared to HCCs that were resected upfront. Methods: We reviewed all patients who underwent surgical resection for HCC between 1st January 2000 and 31st December 2019 and identified those that had locally advanced HCC and were downstaged with Y90-SIRT and referred for consideration of surgical resection. OS and RFS of patients resected upfront for early and locally advanced HCC and those resected after downstaging were obtained using the Kaplan Meier method and compared using Log-rank (Mantel-Cox) test after propensity score matching. Results: 1141 patients had surgical resection for HCC within the study period. 245 patients were excluded for other primary cancers or metastatic disease at diagnosis. 875 were resected upfront (473 early, 402 locally advanced) and 23 locally advanced HCC were downstaged with SIRT before resection. Locally advanced HCC patients downstaged with Y90 before resection have significantly better OS and RFS than locally advanced HCC with upfront resection (5-year OS of 69.0% versus 47.5% p = 0.048; 5-year RFS of 53.5% vs 27.0%, p = 0.047) and similar OS and RFS with resected early HCC (5-year OS of 69.0% versus 62.6% p=0.475; 5-year RFS of 53.5% vs 39.0%, p = 0.736). Conclusions: In addition to downstaging HCC to resection, Y90-SIRT also produces a change in tumour biology that favours better prognosis. A randomised controlled trial to the role of SIRT as neoadjuvant therapy in locally advanced HCC is justified and can potentially change practice.

Liver Resection and Transplantation Following Yttrium-90 Radioembolization for Primary Malignant Liver Tumors: A 15-Year Single-Center Experience.

Patients diagnosed with HCC and ICC treated by RE with further liver resection (LR) or LT between 2005-2020 were included. All patients selected were discarded for the upfront surgical approach for not accomplishing oncological or surgical safety criteria after a multidisciplinary team assessment. Data for clinicopathological details, postoperative, and survival outcomes were retrospectively reviewed from a prospectively maintained database. A total of 34 patients underwent surgery following RE (21 LR and 13 LT). Clavien-Dindo grade III-IV complications and mortality rates were 19.0% and 9.5% for LR and 7.7% and 0% for LT, respectively. After RE, for HCC and ICC patients in the LR group, 10-year OS rates were 57% and 60%, and 10-year DFS rates were 43.1% and 60%, respectively. For HCC patients in the LT group, 10-year OS and DFS rates from RE were 51.3% and 43.3%, respectively. Liver resection after RE is safe and feasible with optimal short-term outcomes. Patients diagnosed with unresectable or high biological risk HCC or ICC, treated with RE, and rescued by LR may achieve optimal global and DFS rates. On the other hand, bridging or downstaging strategies to LT with RE in HCC patients show adequate recurrence rates as well as long-term survival.

Microfluidic Fabrication of Silica Microspheres Infused with Positron Emission Tomography Imaging Agents.

Selective internal radiation therapy (SIRT) is a treatment which delivers radioactive therapeutic microspheres via the hepatic artery to destroy tumorigenic tissue of the liver. However, the dose required varies significantly from patient to patient due to nuances in individual biology. Therefore, a positron emission tomography (PET) imaging surrogate, or radiotracer, is used to predict in vivo behavior of therapeutic Y-90 spheres. The ideal surrogate should closely resemble Y-90 microspheres in morphology for highest predictive accuracy. This work presents the fabrication of positron-emitting silica microspheres infused with PET radiotracers copper, fluorine, and gallium. A quick one-pot synthesis is used to create precursor sol, followed by droplet formation with flow-focusing microfluidics, and finally thermal treatment to yield 10-50 μm microspheres with narrow size distribution. Loading of the infused element is controllable in the sol synthesis, while the final sphere size is tunable based on microfluidic flow rates and device channel width. The system is then employed to make radioactive Ga-68 microspheres, which are tested for radioactivity and stability. The fabrication method can be completed within a few hours, depending on the desired microsphere quantity. A microfluidic system is applied to fabricate silica particles loaded with diverse elemental infusions, including radioactive Ga-68.

Is the Y90-radioembolization treatment effective on the intermediate-advanced stage of hepatocellular carcinoma and what is the albumin-bilirubin score's prediction factor for survival?

Radioembolization (RE) is a one of the palliative treatments that have been used to down stage and/or increase the survival time in intermediate-advanced stages of HCC. We aimed to evaluate the clinical impact of RE and the clinical use of the albumin-bilirubin (ALBI) score as a predictor for survival in HCC patients. Fifty-nine unresectable hepatocellular carcinoma (HCC) patients were enrolled. RE was performed in 28 of them (group 1) and 31 patients were followed up in the natural course (NC) (group 2). Patients were classified according to the Child-Pugh score (only cirrhotic patients), Barcelona clinic liver cancer (BCLC) staging, and ALBI scores were also calculated. All patients in Group 1 were cirrhotic and their BCLC stages were as follows: 60.7% stage B and 39.3% stage C. In Group 2, 83.9% of patients were cirrhotic and their BCLC stages were as follows: 9.7% stage B, 51.6% stage C, and 38.7% stage D. Mortality rates were 82% and 100% in Groups 1 and 2, respectively. The median overall survival (OS) was 13.5 months (95% CI: 10.4-16.6 months) and 4.5 months (95% CI: 3.5-5.5 months) in Groups 1 and 2, respectively (p=0.000). When RE was applied to patients with ALBI Grade 1 and 2, the median OS was statistically higher than in the NC group, respectively (p<0.001, p<0.001). RE is an effective treatment method at the advanced stages of HCC. The ALBI score is a more useful and practical than the other prognostic tools.

Liver Resection in Patients with Hepatocellular Carcinoma after Selective Internal Radiation Therapy. Single Centre Experience

Liver Resection in Patients with Hepatocellular Carcinoma after Selective Internal Radiation Therapy. Single Centre Experience

Intraoperative indocyanine green clearance in liver surgery: a useful tool to promote parenchymal preservation?

A 66-year-old woman was diagnosed with sigmoid carcinoma with bilobar unresectable liver metastases. Primary tumor resection was performed. Neoadjuvant chemotherapy was administered to downstage liver disease. Following FOLFOX/panitumumab (4 cycles), disease progression was observed within the liver. Therefore, chemotherapy regimen was switched to FOLFIRI/cetuximab (12 cycles). At restaging, 7 out of 10 metastases showed complete radiologic response and 3 showed disease progression. Selective internal radiation therapy (SIRT) with Yttrium-90 was performed on these 3 metastases with very good local radiologic response. Surgical resection with curative intent was attempted. ICG was administered 72 hours before surgery to help localization of liver metastases. Intraoperatively, very poorICG clearance was demonstrated and therefore parenchyma-sparing resections were performed (segment II, III, IV and VII). At final histology, major pathologic response was observed with steatosis of the liver parenchyma. Postoperative course was uneventful and adjuvant capecitabine was administered (8 cycles). No recurrence was demonstrated at 38 months follow-up. However, eighteen months following surgery, she developed impairment of hepatic function and portal hypertension. Conclusion: Preoperative ICG administration could be helpful to intraoperatively detect patients that can develop late post hepatectomy impairment of hepatic function, especially following SIRT2 (REF2), and promote parenchymal preservation.

Selective internal radiation therapy across Barcelona Clinic Liver Cancer (BCLC) stages of hepatocellular carcinoma: literature review

Selective internal radiation therapy across Barcelona Clinic Liver Cancer (BCLC) stages of hepatocellular carcinoma: literature review

The Current Status and Future Prospects for Conversion Therapy in the Treatment of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide. In China, most HCC patients are diagnosed with advanced disease and in these cases surgery is challenging. Conversion therapy can be used to change unresectable HCC into resectable disease and is a potential breakthrough treatment strategy. The resection rate for unresectable advanced HCC has recently improved as a growing number of patients have benefited from conversion therapy. While conversion therapy is at an early stage of development, progress in patient selection, optimum treatment methods, and the timing of surgery have the potential to deliver significant benefits. In this article, we review the current evidence and clinical experience of conversion therapy in HCC. General conversion modalities such as systemic treatments (systemic chemotherapy, targeted therapy, or immunotherapy), locoregional therapy (transarterial chemoembolization, hepatic arterial infusion chemotherapy, or selective internal radiation therapy), and combination therapy were summarized. We also discuss the current challenges of conversion therapy and provide identify areas for future research to improve the development of conversion therapy in advanced HCC.

Selective Internal Radiotherapy in Germany: a review of indications and hospital mortality from 2012 to 2019

Selective Internal Radiotherapy in Germany: a review of indications and hospital mortality from 2012 to 2019

Main challenges in radiation protection with emerging radionuclide therapies.

The recent development of radionuclide therapy and radioligand therapy has raised a call for achieving the highest quality standards, for either radiopharmacy or radiation protection. Novel radionuclides are now being used, either under the form of in-house production radiopharmaceuticals or available from companies. Over the last 20 years, they include radiolabeled microspheres for selective internal radiotherapy (SIRT), the introduction of the first commercially available alpha emitter radiopharmaceutical, 223Ra, and the radiosynoviorthesis which is highly variable across Europe. More important is the development of radioligand therapy, often called theranostics. In this concept, a diagnostic radiopharmaceutical can determine the chance of success of a therapeutic one. Typically, diagnostic radiopharmaceuticals for positron emission tomography, are labeled with 18F or 68Ga, such as the PSMA ligands or somatostatin analogs, and the therapeutic radiopharmaceutical is labeled with 177Lu. This has revolutionized the world of Nuclear Medicine, but also all concepts that shall be applied to properly apply quality assurance and radiation protection in the field. This article will follow the example of 131I as the main used radionuclide for therapy during the last 80 years. Proposals can be general, and in parallel expert's articles will give specific guidance on issues with particular radionuclides, i.e., alpha emitters and 177Lu. This article will also give insight in the radiation protection issues related to the use of microspheres radiolabeled with either 90Y or 166Ho.

Intra- and inter-operator variability in MRI-based manual segmentation of HCC lesions and its impact on dosimetry

PurposeThe aim was to quantify inter- and intra-observer variability in manually delineated hepatocellular carcinoma (HCC) lesion contours and the resulting impact on radioembolization (RE) dosimetry.MethodsTen patients with HCC lesions treated with Y-90 RE and imaged with post-therapy Y-90 PET/CT were selected for retrospective analysis. Three radiologists contoured 20 lesions manually on baseline multiphase contrast-enhanced MRIs, and two of the radiologists re-contoured at two additional sessions. Contours were transferred to co-registered PET/CT-based Y-90 dose maps. Volume-dependent recovery coefficients were applied for partial volume correction (PVC) when reporting mean absorbed dose. To understand how uncertainty varies with tumor size, we fit power models regressing relative uncertainty in volume and in mean absorbed dose on contour volume. Finally, we determined effects of segmentation uncertainty on tumor control probability (TCP), as calculated using logistic models developed in a previous RE study.ResultsThe average lesion volume ranged from 1.8 to 194.5 mL, and the mean absorbed dose ranged from 23.4 to 1629.0 Gy. The mean inter-observer Dice coefficient for lesion contours was significantly less than the mean intra-observer Dice coefficient (0.79 vs. 0.85, p < 0.001). Uncertainty in segmented volume, as measured by the Coefficient of Variation (CV), ranged from 4.2 to 34.7% with an average of 17.2%. The CV in mean absorbed dose had an average value of 5.4% (range 1.2–13.1%) without PVC while it was 15.1% (range 1.5–55.2%) with PVC. Using the fitted models for uncertainty as a function of volume on our prior data, the mean change in TCP due to segmentation uncertainty alone was estimated as 16.2% (maximum 48.5%).ConclusionsThough we find relatively high inter- and intra-observer reliability overall, uncertainty in tumor contouring propagates into non-negligible uncertainty in dose metrics and outcome prediction for individual cases that should be considered in dosimetry-guided treatment.

HPB P05 Loco-regional Treatment of Metachronous Oligometastases in Pancreatic Adenocarcinoma; A systematic Review

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is the twelfth commonest cancer worldwide, and predicted to be the second most common cause of cancer death by 2030. Outcomes are poor, just 20% of patients present with resectable disease of which up to 85% recur post-surgery. Loco-regional treatment of limited metastatic recurrence, termed metachronous oligometastases (a transitional state between localised and widespread systemic disease) may confer a survival benefit. In 2020 the European Organisation for Research and Treatment of Cancer recommended definitions for characterisation and classification of oligometastatic disease using consensus methods. However, there remains no universally agreed definition of this disease state, which may contribute to heterogeneous outcome reporting and limit comparison between studies. The aim of this systematic review is to i) summarise the published loco-regional treatments of metachronous oligometastatic PDAC and ii) identify reported definitions of the oligometastatic state. Methods All articles reporting management and outcomes for patients with metachronous oligometastatic PDAC cancer were eligible for inclusion. Searches for ‘pancreatic cancer’ and ‘oligometastatic disease’ were undertaken via Medline, Embase, PubMed, Web of Science, the Cochrane Central Register of Controlled Trials and Google Scholar. Bibliographies of relevant studies were used to identify additional studies. Screening was performed independently by at least two authors. Articles produced in languages other than English, abstracts and conference proceedings, case reports, reports of fewer than five patients, and articles published before 2000 were excluded. The full-text versions of articles were accessed for further assessment. Data extraction was undertaken independently by at least two authors using a standardised proforma including general demographics, treatment of primary, recorded definitions of oligometastatic disease, methods of treatment for liver oligometastatic disease, local recurrence, other sites of recurrence, and survival outcomes. Results 6602 articles were identified for title screening, 284 for full-text review and 35 articles were included, of which 29 were case series and six were non-randomised comparative studies. Of these, 29 (83%) were retrospective. Five (14%) were multicentre, and participant numbers ranged from 10 to 332. Descriptions of oligometastatic disease were variable, with no study using the same definition. No studies reported an oligometastatic subtype as described by the European Organisation for Research and Treatment of Cancer consensus recommendation. Liver oligometastases were reported in 15 studies and demonstrated variable treatments including radiofrequency (4), stereotactic body radiotherapy (SBRT) (2), and selective internal radiation therapy (SIRT) (2). Nine studies reported surgical management of liver metastasis. The Median overall survival (OS) for these treatments was 29.5, 28.9, 27.5, and 39.5 months respectively. Management of local recurrence was reported in 22 studies and included SBRT (9), trans-arterial chemoembolisation (4) radiofrequency (1), and surgical resection (8). Median OS were 28.1, 29.9, 79.3 and 49.3 respectively. Three studies reported on the treatment of peritoneal oligometastases, including SIRT (1) and surgical resection (2) with Median OS as 12.3 and 61 months respectively. Conclusions The majority of studies were single-centre, non-randomised retrospective, without comparators and with low patient numbers. Treatments offered for local and distant recurrence were heterogeneous. There was no consensus for the definition of oligometastatic disease, which resulted in a lack of consistent patient selection. There is an urgent need for future studies to use a consistent definition to allow for a more homogenous patient selection and allow meaningful comparison of treatment delivery and outcomes.

A Theranostic Approach in SIRT: Value of Pre-Therapy Imaging in Treatment Planning

Selective internal radiation therapy (SIRT) is one of the treatment options for liver tumors. Microspheres labelled with a therapeutic radionuclide (90Y or 166Ho) are injected into the liver artery feeding the tumor(s), usually achieving a high tumor absorbed dose and a high tumor control rate. This treatment adopts a theranostic approach with a mandatory simulation phase, using a surrogate to radioactive microspheres (99mTc-macroaggregated albumin, MAA) or a scout dose of 166Ho microspheres, imaged by SPECT/CT. This pre-therapy imaging aims to evaluate the tumor targeting and detect potential contraindications to SIRT, i.e., digestive extrahepatic uptake or excessive lung shunt. Moreover, the absorbed doses to the tumor(s) and the healthy liver can be estimated and used for planning the therapeutic activity for SIRT optimization. The aim of this review is to evaluate the accuracy of this theranostic approach using pre-therapy imaging for simulating the biodistribution of the microspheres. This review synthesizes the recent publications demonstrating the advantages and limitations of pre-therapy imaging in SIRT, particularly for activity planning.

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.

A descriptive analysis of the characteristics, treatment response and prognosis of hepatic dominant solid tumors undergoing selective internal radiation therapy (SIRT)

Selective internal radiotherapy is widely used for liver dominant diseases of solid tumors. However, data about sequential treatment and prognostic factors are lacking. We consecutively included all 209 patients who received a selective internal radiotherapy intervention between January 2015 and May 2019. A retrospective analysis of their electronic patient records was performed regarding diagnosis of cancer, previous therapies and applied radioactive activity. A multicenter follow-up at least 6 weeks after intervention to assess radiological response and irregular subsequent follow-ups to asses disease progression were conducted. In addition, subgroup analyses were carried out. The most frequently treated indications were hepatocellular carcinoma (37%), colorectal cancers (14%), neuroendocrine tumors (9%), and breast cancer (8%). In hepatocellular carcinoma, selective internal radiotherapy was most performed without prior systemic therapy (40%), and for the remaining indications, most often after surgery with systemic therapy in sequence. Local radiological response, defined as either regression or stable disease, was assessed at least 6 weeks after intervention and showed 52% across all indications. Hepatocellular carcinoma (59%) and breast cancer (67%) showed an excellent, colorectal cancers (29%) a particularly poor response rate. Neuroendocrine tumors showed the third longest median post-selective internal radiation therapy (SIRT) survival with 12.4 months and the second longest median progression-free time with 5.2 months. Hepatocellular carcinoma showed even better results with a post-SIRT survival of 15.7 months and a median progression-free time of 5.3 months. Pancreatic neuroendocrine tumors showed significantly worse outcomes than other neuroendocrine tumors, regarding median post-SIRT survival and median progression-free time. No relevant SIRT related differences among sexes were detected. Patients with neuroendocrine tumors, breast cancer in late therapy lines and early-stage hepatocellular carcinoma seem to show better responses to SIRT than other entities. Colorectal cancers were mainly treated with SIRT in a second or third therapy line but with considerably weaker results than other entities.

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.

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.

EE350 Selective Internal Radiation Therapy Using Y-90 Resin Microspheres vs Conventional Transarterial Chemoembolization in Barcelona Clinic Liver Cancer Stage B Hepatocellular Carcinoma: A Budget Impact Analysis in England

Selective internal radiation therapy (SIRT) is a well-tolerated treatment for hepatocellular carcinoma (HCC) that has been investigated extensively in patients with HCC in Barcelona Clinic Liver Cancer (BCLC) stage B. The present analysis aimed to evaluate the budgetary implications of using SIRT versus conventional transarterial chemoembolization (cTACE) in treating patients with BCLC B HCC in England.