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.

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

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

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

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

Hepatic Radioembolization: A Multistep Theragnostic Procedure.

This article provides a thorough overview of the practice and multistep approach of hepatic radioembolization. The current literature on hepatic radioembolization in primary or metastatic liver tumors as well as future perspectives are discussed.

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.

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.

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.

[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.

Energy window optimization in bremsstrahlung imaging after Yttrium-90 microsphere therapy.

In imaging of Yttrium-90 patients treated hepatic primary and metastatic cancers, bremsstrahlung photons produced in a wide energy range is used. However, the image quality depends on acquisition energy window. This research aimed energy window optimization for Yttrium-90 bremsstrahlung imaging and 48 patients with various types of cancer received radioembolization therapy were investigated. Patients were imaged using a GE Healthcare Optima NM/CT 640 series gamma camera system with a medium energy general-purpose (MEGP) collimator and planar images were acquired with 8 different energy windows in the 55-400 keV energy range. The data set, formed with the % FOV, contrast, and spatial resolution of image quality parameters calculated from these images, was statistically examined with ANOVA and Tukey tests. According to the visual evaluations and ANOVA/Tukey test results, it was statistically concluded that energy window of 90-110 keV is the optimal energy window while 60-400 keV energy ranges show the lowest image quality for Y-90 bremsstrahlung imaging.

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.

90Y post-radioembolization clinical assessment with whole-body Biograph Vision Quadra PET/CT: image quality, tumor, liver and lung dosimetry.

PURPOSE: Evaluation of 90Y liver radioembolization post-treatment clinical data using a whole-body Biograph Vision Quadra PET/CT to investigate the potential of protocol optimization in terms of scan time and dosimetry. METHODS: 17 patients with hepatocellular carcinoma with median (IQR) injected activity 2393 (1348-3298) MBq were included. Pre-treatment dosimetry plan was based on 99mTc-MAA SPECT/CT with Simplicit90Y™ and post-treatment validation with Quadra using Simplicit90Y™ and HERMIA independently. Regarding the image analysis, mean and peak SNR, the coefficient of variation (COV) and lesion-to-background ratio (LBR) were evaluated. For the post-treatment dosimetry validation, the mean tumor, whole liver and lung absorbed dose evaluation was performed using Simplicit90Y and HERMES. Images were reconstructed with 20-, 15-, 10-, 5- and 1- min sinograms with 2, 4, 6 and 8 iterations. Wilcoxon signed rank test was used to show statistical significance (p < 0.05). RESULTS: There was no difference of statistical significance between 20- and 5- min reconstructed times for the peak SNR, COV and LBR. In addition, there was no difference of statistical significance between 20- and 1- min reconstructed times for all dosimetry metrics. Lung dosimetry showed consistently lower values than the expected. Tumor absorbed dose based on Simplicit90Y™ was similar to the expected while HERMES consistently underestimated significantly the measured tumor absorbed dose. Finally, there was no difference of statistical significance between expected and measured tumor, whole liver and lung dose for all reconstruction times. CONCLUSION: In this study we evaluated, in terms of image quality and dosimetry, whole-body PET clinical images of patients after having been treated with 90Y microspheres radioembolization for liver cancer. Compared to the 20-min standard scan, the simulated 5-min reconstructed images provided equal image peak SNR and noise behavior, while performing also similarly for post-treatment dosimetry of tumor, whole liver and lung absorbed doses.

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.