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

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

Myeloid-derived suppressor cells attenuate the antitumor efficacy of radiopharmaceutical therapy using 90Y-NM600 in combination with androgen deprivation therapy in murine prostate tumors.

RATIONALE: Androgen deprivation therapy (ADT) is pivotal in treating recurrent prostate cancer and is often combined with external beam radiation therapy (EBRT) for localized disease. However, for metastatic castration-resistant prostate cancer, EBRT is typically only used in the palliative setting, because of the inability to radiate all sites of disease. Systemic radiation treatments that preferentially irradiate cancer cells, known as radiopharmaceutical therapy or targeted radionuclide therapy (TRT), have demonstrable benefits for treating metastatic prostate cancer. Here, we explored the use of a novel TRT, 90Y-NM600, specifically in combination with ADT, in murine prostate tumor models. METHODS: 6-week-old male FVB mice were implanted subcutaneously with Myc-CaP tumor cells and given a single intravenous injection of 90Y-NM600, in combination with ADT (degarelix). The combination and sequence of administration were evaluated for effect on tumor growth and infiltrating immune populations were analyzed by flow cytometry. Sera were assessed to determine treatment effects on cytokine profiles. RESULTS: ADT delivered prior to TRT (ADT→TRT) resulted in significantly greater antitumor response and overall survival than if delivered after TRT (TRT→ADT). Studies conducted in immunodeficient NRG mice failed to show a difference in treatment sequence, suggesting an immunological mechanism. Myeloid-derived suppressor cells (MDSCs) significantly accumulated in tumors following TRT→ADT treatment and retained immune suppressive function. However, CD4+ and CD8+ T cells with an activated and memory phenotype were more prevalent in the ADT→TRT group. Depletion of Gr1+MDSCs led to greater antitumor response following either treatment sequence. Chemotaxis assays suggested that tumor cells secreted chemokines that recruited MDSCs, notably CXCL1 and CXCL2. The use of a selective CXCR2 antagonist, reparixin, further improved antitumor responses and overall survival when used in tumor-bearing mice treated with TRT→ADT. CONCLUSION: The combination of ADT and TRT improved antitumor responses in murine models of prostate cancer, however, this was dependent on the order of administration. This was found to be associated with one treatment sequence leading to an increase in infiltrating MDSCs. Combining treatment with a CXCR2 antagonist improved the antitumor effect of this combination, suggesting a possible approach for treating advanced human prostate cancer.

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.

Radiosynovectomy in haemophilic synovitis and arthropathy of the knee: A scoping review.

INTRODUCTION: Radiosynovectomy is an established treatment for chronic synovitis in patients with haemophilia. Although its role in rheumatological diseases has diminished, it remains an accepted therapy for haemophilic synovitis. AIM: The aim of this scoping review was to map and summarise the evidence surrounding radiosynovectomy in haemophilic knees, identify gaps in the literature and inform future research. RESULTS: Forty-three manuscripts and abstracts were identified for this review. Evidence was limited to observational studies and Yttrium-90 was the most studied licensed radioisotope. Radiosynovectomy was associated with a reduction in bleeding frequency and pain, improvements in range of motion and a reduction in the use of factor replacement. CONCLUSION: The literature reviewed lacks studies of sufficient methodological quality to permit systematic review and meta-analysis. Systematic review using risk of bias assessment for observational studies should be undertaken to better evaluate the efficacy and safety of radiosynovectomy. A causal relationship between RSV and key clinical outcomes remains undetermined.

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.

Tumor Size and Watershed Area Correlate with Incomplete Treatment and Tumor Progression after Selective Radioembolization for Hepatocellular Carcinoma.

PURPOSE: To identify factors of incomplete treatment after segmental transarterial radioembolization (TARE) for treatment-naive and solitary hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 75 consecutive patients (age, 68.5 years [SD ± 8.0]; 25/75 [33.3%] women) with treatment-naive, solitary HCC underwent segmental or subsegmental TARE with glass microspheres (tumor size, 3.8 cm [SD ± 2.2]; administered dose, 222.6 Gy [SD ± 123.9]) at a single institution from November 2015 to June 2022. Radiologic response and progression-free survival (PFS) were assessed as per modified Response Evaluation Criteria in Solid Tumors. RESULTS: Complete treatment was achieved in 48 of 75 (64.0%) patients (mean follow-up, 33.2 months [SD ± 27.4]). Patients with incomplete treatment (27/75, 36%) presented with larger tumor size (5.0 [SD ± 2.5] vs 3.1 [SD ± 1.6] cm; P = .0001), with more tumors located in the watershed zone (81.5% vs 41.7%; P = .001). These patients were less likely to be bridged to transplant or resection (22.2% vs 52.1%; P = .015). Watershed tumors demonstrated worse target tumor PFS (median PFS, 19 months vs not reached; P = .0104) and overall PFS (9.1 months vs not reached; P = .0077). Watershed location was associated with worse PFS among tumors >3 cm in size (8.4 months vs not reached; P = .035) but not in tumors ≤3 cm in size (52.2 months vs not reached; P = .915). CONCLUSIONS: Tumor size and watershed location were associated with incomplete treatment after segmental TARE for HCC. Watershed tumors were associated with worse PFS, particularly tumors larger than 3 cm. These tumors may require careful treatment planning and repeated treatments to ensure a durable response.

Radioembolization plus Immune Checkpoint Inhibitor Therapy Compared with Radioembolization plus Tyrosine Kinase Inhibitor Therapy for the Treatment of Hepatocellular Carcinoma.

PURPOSE: To investigate if combination therapy with immune checkpoint inhibitor (ICI) and yttrium-90 (90Y) radioembolization results in superior outcomes than those yielded by tyrosine kinase inhibitor (TKI) therapy and 90Y for the treatment of intermediate- to advanced-stage hepatocellular carcinoma (HCC). METHODS: A retrospective review of patients presented at an institutional multidisciplinary liver tumor board between January 1, 2012 and August 1, 2023 was conducted. In total, 44 patients with HCC who underwent 90Y 4 weeks within initiation of ICI or TKI therapy were included. Propensity score matching was conducted to account for baseline demographic differences. Kaplan-Meier analysis was used to compare median progression-free survival (PFS) and overall survival (OS), and univariate statistics identified disease response and control rate differences. Duration of imaging response was defined as number of months between the first scan after therapy and the first scan showing progression as defined by modified Response Evaluation Criteria in Solid Tumors (mRECIST) or immune Response Evaluation Criteria in Solid Tumors (iRECIST). Adverse events were analyzed per Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. RESULTS: Patients in the 90Y+ICI therapy group had better objective response rates (ORRs) (89.5% vs 36.8%; P < .001) and disease control rates (DCRs) (94.7% vs 63.2%; P < .001) by mRECIST and iRECIST (ORR: 78.9% vs 36.8%; P < .001; DCR: 94.7% vs 63.2%; P < .001). Median PFS (8.3 vs 4.1 months; P = .37) and OS (15.8 vs 14.3 months; P = .52) were not statistically different. Twelve patients (63.1%) in the 90Y+TKI group did not complete systemic therapy owing to adverse effects compared with 1 patient (5.3%) in the 90Y+ICI group (P < .001). Grade 3/4 adverse events were not statistically different (90Y+TKI: 21.1%; 90Y+ICI: 5.3%; P = .150). CONCLUSIONS: Patients with HCC who received 90Y+ICI had better imaging response and fewer regimen-altering adverse events than those who received 90Y+TKI. No significant combination therapy adverse events were attributable to radioembolization.

Selective Internal Radiation Therapy Using Y-90 Resin Microspheres for Metastatic Colorectal Cancer: An Updated Systematic Review and Network Meta-Analysis.

INTRODUCTION: This literature review and exploratory network meta-analysis (NMA) aimed to compare the clinical effectiveness and tolerability of selective internal radiation therapy (SIRT) using yttrium-90 (Y-90) resin microspheres, regorafenib (REG), trifluridine-tipiracil (TFD/TPI), and best supportive care (BSC) in adult patients with chemotherapy-refractory or chemotherapy-intolerant metastatic colorectal cancer (mCRC). METHODS: In light of recently published data, the literature was searched to complement and update a review published in 2018. Studies up to December 2022 comparing two or more of the treatments and reporting overall survival (OS), progression-free survival (PFS), or incidence of adverse events (AE) were included. The NMA compared hazard ratios (HRs) for OS and PFS using Markov chain Monte Carlo techniques. RESULTS: Fifteen studies were included, with eight studies added (none addressing SIRT). All active treatments improved OS in relation to BSC. SIRT had the longest OS among all treatments, although without statistically significant differences (HR [95% credible interval] for SIRT, 0.48 [0.27, 0.87]; TFD/TPI, 0.62 [0.46, 0.83]; REG, 0.78 [0.57, 1.05]) in a fixed effects model. Information regarding SIRT was insufficient for PFS analysis, and TFD/TPI was the best intervention (HR 2.26 [1.6, 3.18]). One SIRT study reported radioembolization-induced liver disease in > 10% of the sample; this was symptomatically managed. Non-haematological AEs (hand-foot skin reaction, fatigue, diarrhoea, hypertension, rash or desquamation) were more common with REG, while haematological events (neutropoenia, leukopenia, and anaemia) were more common with TFD/TPI. CONCLUSION: Current evidence supports SIRT treatment in patients with chemotherapy-refractory or chemotherapy-intolerant mCRC compared to newer oral agents, with comparable OS and low incidence of AEs.

Lung Mean Dose Prediction in Transarterial Radioembolization (TARE): Superiority of [166Ho]-Scout Over [99mTc]MAA in a Prospective Cohort Study.

PURPOSE: Radiation pneumonitis is a serious complication of radioembolization. In holmium-166 ([166Ho]) radioembolization, the lung mean dose (LMD) can be estimated (eLMD) using a scout dose with either technetium-99 m-macroaggregated albumin ([99mTc]MAA) or [166Ho]-microspheres. The accuracy of eLMD based on [99mTc]MAA (eLMDMAA) was compared to eLMD based on [166Ho]-scout dose (eLMDHo-scout) in two prospective clinical studies. MATERIALS AND METHODS: Patients were included if they received both scout doses ([99mTc]MAA and [166Ho]-scout), had a posttreatment [166Ho]-SPECT/CT (gold standard) and were scanned on the same hybrid SPECT/CT system. The correlation between eLMDMAA/eLMDHo-scout and LMDHo-treatment was assessed by Spearman's rank correlation coefficient (r). Wilcoxon signed rank test was used to analyze paired data. RESULTS: Thirty-seven patients with unresectable liver metastases were included. During follow-up, none developed symptoms of radiation pneumonitis. Median eLMDMAA (1.53 Gy, range 0.09-21.33 Gy) was significantly higher than median LMDHo-treatment (0.00 Gy, range 0.00-1.20 Gy; p < 0.01). Median eLMDHo-scout (median 0.00 Gy, range 0.00-1.21 Gy) was not significantly different compared to LMDHo-treatment (p > 0.05). In all cases, eLMDMAA was higher than LMDHo-treatment (p < 0.01). While a significant correlation was found between eLMDHo-scout and LMDHo-treatment (r = 0.43, p < 0.01), there was no correlation between eLMDMAA and LMDHo-treatment (r = 0.02, p = 0.90). CONCLUSION: [166Ho]-scout dose is superior in predicting LMD over [99mTc]MAA, in [166Ho]-radioembolization. Consequently, [166Ho]-scout may limit unnecessary patient exclusions and avoid unnecessary therapeutic activity reductions in patients eligible for radioembolization. TRAIL REGISTRATION: NCT01031784, registered December 2009. NCT01612325, registered June 2012.

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.

Real-world evidence of Pressure-Enabled Drug Delivery for trans-arterial chemoembolization and radioembolization among patients with hepatocellular carcinoma and liver metastases.

OBJECTIVES: Pressure-Enabled Drug Delivery (PEDD), a method using pressure to advance catheter-delivered drug distribution, can improve treatment for hepatocellular carcinoma (HCC) and liver metastases, but real-world evidence is limited. We compared baseline patient characteristics, clinical complexity, and post-procedure healthcare resource utilization (HRUs) and clinical complications for PEDD and non-PEDD procedures. METHODS: This study used a retrospective, longitudinal, cohort design of claims data from Clarivate's Real World Data Repository, which includes 98% of US payers with over 300 million unique patients from all US states. We identified patients with a trans-arterial chemoembolization (TACE) or trans-arterial radioembolization (TARE) from 1 January 2019 to 31 December 2022. Subsamples grouped patients with HCC receiving a TARE procedure at their first embolization and patients with metastatic colorectal cancer (CRC) that received a TARE procedure. We reported descriptive comparisons of our full sample of patients with HCC and liver metastases receiving PEDD versus non-PEDD procedures. We then conducted a matching-adjusted comparison of HRUs and clinical complications for PEDD and non-PEDD patients among our subsamples (HCC receiving a TARE procedure at their first embolization and patients with metastatic CRC that received a TARE procedure). Matching was based on baseline demographic and clinical characteristics using coarsened exact matching and propensity-score matching. HRUs included inpatient, outpatient, and emergency department visits. Clinical complications included ascites, cholecystitis, fatigue, gastric ulcer, gastritis, jaundice, LFT increase, lymphopenia, portal hypertension, and post-embolization syndrome. RESULTS: PEDD procedures were used on patients with worse baseline disease burdens: baseline Charlson comorbidity index (mean of 6.5 vs. 5.8), any prior clinical complication related to underlying disease (33.7 vs. 31.0%), and prior systemic therapy (22.1% vs. 16.2%). PEDD patients had a greater number of procedural codes indicative of technical complexity for TACE (PEDD mean = 226.3; non-PEDD mean = 134.5; p value <.01) and TARE (PEDD mean = 205.56; non-PEDD mean = 94.8; p value <0.01). Matching-adjusted analyses of patients with HCC and CRC demonstrated comparable HRU and clinical complications for PEDD and non-PEDD procedures post-index. CONCLUSION: Despite higher baseline disease burden and complexity, post-procedure HRU and clinical complications for PEDD patients were similar to non-PEDD patients. The complex baseline clinical profile may reflect selection of challenging cases for PEDD use. Future studies should validate the benefits observed with PEDD embolization in larger samples with greater statistical power.

PET/CT and SPECT/CT imaging of 90Y hepatic radioembolization at therapeutic and diagnostic activity levels: Anthropomorphic phantom study.

PURPOSE: Prior to 90Y radioembolization procedure, a pretherapy simulation using 99mTc-MAA is performed. Alternatively, a small dosage of 90Y microspheres could be used. We aimed to assess the accuracy of lung shunt fraction (LSF) estimation in both high activity 90Y posttreatment and pretreatment scans with isotope activity of ~100 MBq, using different imaging techniques. Additionally, we assessed the feasibility of visualising hot and cold hepatic tumours in PET/CT and Bremsstrahlung SPECT/CT images. MATERIALS AND METHODS: Anthropomorphic phantom including liver (with two spherical tumours) and lung inserts was filled with 90Y chloride to simulate an LSF of 9.8%. The total initial activity in the liver was 1451 MBq, including 19.4 MBq in the hot sphere. Nine measurement sessions including PET/CT, SPECT/CT, and planar images were acquired at activities in the whole phantom ranging from 1618 MBq down to 43 MBq. The visibility of the tumours was appraised based on independent observers' scores. Quantitatively, contrast-to-noise ratio (CNR) was calculated for both spheres in all images. RESULTS: LSF estimation. For high activity in the phantom, PET reconstructions slightly underestimated the LSF; absolute difference was <1.5pp (percent point). For activity <100 MBq, the LSF was overestimated. Both SPECT and planar scintigraphy overestimated the LSF for all activities. Lesion visibility. For SPECT/CT, the cold tumour proved too small to be discernible (CNR <0.5) regardless of the 90Y activity in the liver, while hot sphere was visible for activity >200 MBq (CNR>4). For PET/CT, the cold tumour was only visible with the highest 90Y activity (CNR>4), whereas the hot one was seen for activity >100 MBq (CNR>5). CONCLUSIONS: PET/CT may accurately estimate the LSF in a 90Y posttreatment procedure. However, at low activities of about 100 MBq it seems to provide unreliable estimations. PET imaging provided better visualisation of both hot and cold tumours.

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

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

Radiomics-Based Prediction Model for Outcome of Radioembolization in Metastatic Colorectal Cancer.

PURPOSE: To evaluate the benefit of a contrast-enhanced computed tomography (CT) radiomics-based model for predicting response and survival in patients with colorectal liver metastases treated with transarterial Yttrium-90 radioembolization (TARE). MATERIALS AND METHODS: Fifty-one patients who underwent TARE were included in this single-center retrospective study. Response to treatment was assessed using the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) at 3-month follow-up. Patients were stratified as responders (complete/partial response and stable disease, n = 24) or non-responders (progressive disease, n = 27). Radiomic features (RF) were extracted from pre-TARE CT after segmentation of the liver tumor volume. A model was built based on a radiomic signature consisting of reliable RFs that allowed classification of response using multivariate logistic regression. Patients were assigned to high- or low-risk groups for disease progression after TARE according to a cutoff defined in the model. Kaplan-Meier analysis was performed to analyze survival between high- and low-risk groups. RESULTS: Two independent RF [Energy, Maximal Correlation Coefficient (MCC)], reflecting tumor heterogeneity, discriminated well between responders and non-responders. In particular, patients with higher magnitude of voxel values in an image (Energy), and texture complexity (MCC), were more likely to fail TARE. For predicting treatment response, the area under the receiver operating characteristic curve of the radiomics-based model was 0.75 (95% CI 0.48-1). The high-risk group had a shorter overall survival than the low-risk group (3.4 vs. 6.4 months, p < 0.001). CONCLUSION: Our CT radiomics model may predict the response and survival outcome by quantifying tumor heterogeneity in patients treated with TARE for colorectal liver metastases.

Peptide receptor radionuclide therapy with 177Lu- or 90Y-SSTR peptides in malignant pheochromocytomas (PCCs) and paragangliomas (PGLs): results from a single institutional retrospective analysis.

BACKGROUND: Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare tumors and available systemic therapies are limited. AIM: To explore the role of peptide receptor radionuclide therapy (PRRT) with Yttrium-90 (90Y) and Lutetium-177 (177Lu) peptides in pheochromocytomas (PCCs) and paragangliomas (PGLs). METHODS: We retrospectively analyzed more than 1500 patients with histologically proven neuroendocrine tumors treated with 177Lu- or 90Y-DOTA-TATE or -TOC between 1999 to 2017 at our Institute. Overall, 30 patients with confirmed malignant PCCs and PGLs matched inclusion/exclusion criteria and were considered eligible for this analysis. RESULTS: Thirty (n = 30) patients were treated: 22 with PGLs and 8 with PCCs (12 M and 18 F, median age 47 [IQR: 35-60 years]). Eighteen patients (n = 18) had head and neck PGLs, 3 patients thoracic PGLs and 1 patient abdominal PGL. Sixteen patients (53%) had locally advanced and fourteen (47%) had metastatic disease. Twenty-seven (90%) patients had disease progression at baseline. Four (13%) patients were treated with 90Y, sixteen (53%) with 177Lu and ten (33%) with 90Y + 177Lu respectively. The median total cumulative activity from treatment with 90Y- alone was 9.45 GBq (range 5.11-14.02 GBq), from 177Lu- alone was 21.9 GBq (7.55-32.12 GBq) and from the combination treatment was 4.94 GBq from 90Y- and 6.83 GBq from 177Lu- (ranges 1.04-10.1 and 2.66-20.13 GBq, respectively). Seven out of 30 (23%) patients had partial response and 19 (63%) stable disease. Median follow up was 8.9 years (IQR: 2.9-12). The 5-y and 10-y PFS was 68% (95% CI: 48-82) and 53% (95% CI: 33-69), respectively, whereas 5-y and 10-y OS was 75% (95% CI: 54-87) and 59% (95% CI: 38-75), respectively. Grade 3 or 4 acute hematological toxicity occurred in three patients, two with leucopenia and one with thrombocytopenia, respectively. CONCLUSION: PRRT with 177Lu- or 90Y-DOTA-TATE or -TOC is feasible and well tolerated in advanced PGLs and PCCs.

[Expert consensus on the standardized procedure of selective internal radiation therapy with Yttrium-90 microspheres for liver malignancies (2024 edition)].

Yttrium-90 microsphere selective internal radiation therapy (90Y-SIRT) has been used clinically for more than 50 years for liver malignancies, with confirmed safety and efficacy. Although it has been widely used for more than 20 years abroad, 90Y-SIRT is just getting started in China. The procedure of 90Y-SIRT is relatively complex, which need multidisciplinary teamwork and higher requirements for operators. Once the ectopic distribution of 90Y microspheres occurs, it may lead to relatively serious complications. Therefore, it does need to standardize the procedure of 90Y-SIRT to ensure its efficacy, reduce the incidence of complications, and promote the popularization and application in China. It is for these reasons that experts from Chinese College of Interventionalists and Society for Hepato-pancreato-biliary Surgery of Chinese Research Hospital Association formulate the Expert consensus based on the literature evidence and clinical practice, which including patient selection, preoperative imaging examination, aim of 90Y-SIRT, prescription dose calculation, 90Y-SIRT protocol, postoperative management, common adverse reactions and complications, etc.