Liver transplantation following two conversions in a patient with huge hepatocellular carcinoma and portal vein invasion: A case report.

BACKGROUND: Surgical resection and liver transplantation (LT) are the most effective curative options for hepatocellular carcinoma (HCC). However, few patients with huge HCC (> 10 cm in diameter), especially those with portal vein tumor thrombus (PVTT), can receive these treatments. Selective internal radiation therapy (SIRT) can be used as a conversion therapy for them because it has the dual benefit of shrinking tumors and increasing residual hepatic volume. However, in patients with huge HCC, high lung absorbed dose often prevents them from receiving SIRT. CASE SUMMARY: A 35-year-old man was admitted because of emaciation and pain in the hepatic region for about 1 month. The computed tomography scan showed a 20.2 cm × 19.8 cm tumor located in the right lobe-left medial lobes with right portal vein and right hepatic vein invasion. After the pathological type of HCC was confirmed by biopsy, two conversions were presented. The first one was drug-eluting bead transarterial chemoembolization plus hepatic arterial infusion chemotherapy and lenvatinib and sintilimab, converted to SIRT, and the second one was sequential SIRT with continued systemic treatment. The tumor size significantly decreased from 20.2 cm × 19.8 cm to 16.2 cm × 13.8 cm, then sequentially to 7.8 cm × 6.8 cm. In the meantime, the ratio of spared volume to total liver volume increased gradually from 34.4% to 55.7%, then to 62.9%. Furthermore, there was visualization of the portal vein, indicating regression of the tumor thrombus. Finally, owing to the new tumor in the left lateral lobe, the patient underwent LT instead of resection without major complications. CONCLUSION: Patients with inoperable huge HCC with PVTT could be converted to SIRT first and accept surgery sequentially.

Conversion Therapy to Transplant or Surgical Resection in Patients with Unresectable Hepatocellular Carcinoma Treated with Boosted Dose of Yttrium-90 Radiation Segmentectomy.

BACKGROUND/OBJECTIVES: The aim of this study was to assess the efficacy of boosted dose yttrium-90 radioembolization (TARE) as a modality for conversion therapy to transplant or surgical resection in patients with unresectable hepatocellular carcinoma (HCC). METHODS: In this single-center retrospective study, all patients with a diagnosis of HCC who were treated with boosted dose TARE (>190 Gy) between January 2013 and December 2023 were reviewed. Treatment response and decrease in tumor size were assessed with the RECIST v1.1 and mRECIST criteria. Milan and University of California, San Francisco (UCSF), criteria were used to determine transplant eligibility, and Barcelona Clinic Liver Cancer (BCLC) surgical resection recommendations were used to evaluate tumor resectability. RESULTS: Thirty-eight patients with primary HCC who were treated with boosted dose TARE were retrospectively analyzed. The majority of the patients were Child-Pugh A (n = 35; 92.1%), BCLC C (n = 17; 44.7%), and ECOG performance status 0 (n = 25; 65.8%). The mean sum of the target lesions was 6.0 cm (standard deviation; SD = 4.0). The objective response rate (ORR) was 31.6% by RECIST and 84.2% by mRECIST. The disease control rate (DCR) was 94.7% by both RECIST and mRECIST. Among patients outside of Milan or UCSF, 13/25 (52.0%, Milan) and 9/19 (47.4%, UCSF) patients were successfully converted to within transplant criteria. Of patients who were initially unresectable, conversion was successful in 7/26 (26.9%) patients. CONCLUSIONS: This study provides further real-world data demonstrating that boosted-dose TARE is an effective modality for conversion of patients with unresectable HCC to transplant or resection.

Transarterial radioembolization vs transarterial chemoembolization with drug-eluting beads for treating hepatocellular carcinoma: a cost-effectiveness analysis in Japanese healthcare system.

PURPOSE: Transarterial radioembolization (TARE) is effective for unresectable hepatocellular carcinoma; however, it awaits approval in Japan. This study aimed to simulate the cost-effectiveness of TARE over chemoembolization when TARE is approved in Japan and identify the requirements for cost-effectiveness. MATERIALS AND METHODS: A Markov model was constructed to analyze the costs and effectiveness associated with TARE and transarterial chemoembolization with drug-eluting beads (DEB-TACE) for 2-month cycles over 5 years. In the primary analysis, the intention-to-treat survival data were used to calculate transition probabilities, whereas the ancillary analysis assessed the per-protocol survival data. DEB-TACE costs were calculated using the Japanese nationwide claims Diagnosis Procedure Combination database between April 2018 and March 2022, whereas TARE costs were estimated using database and international sources. The incremental cost-effectiveness ratio (ICER) was determined based on the payer's perspective and compared with the Japanese willingness-to-pay threshold of 5 million Japanese yen (JPY) (31,250 USD) per quality-adjusted life years (QALY). RESULTS: From the claims database, 6,986 patients with hepatocellular carcinoma who received DEB-TACE were identified. In the primary analysis, the ICER was 5,173,591 JPY (32,334 USD)/QALY, surpassing the Japanese willingness-to-pay threshold. However, the ancillary analysis showed a lower ICER of 4,156,533 JPY (25,978 USD)/QALY, falling below the threshold. The one-way deterministic sensitivity analysis identified progression-free survival associated with TARE and DEB-TACE, DEB-TACE costs, and radioactive microsphere reimbursement price as key ICER influencers. The primary analysis suggested that setting the reimbursement price of radioactive microspheres below 1.399 million JPY (8,744 USD), approximately 2.8% lower than the price in the United Kingdom, would place the ICER below the Japanese willingness-to-pay threshold. CONCLUSIONS: Under specific conditions, TARE can be a more cost-effective treatment than DEB-TACE. If the reimbursement price of radioactive microspheres is set approximately 2.8% lower than that in the United Kingdom, TARE could be cost-effective compared with DEB-TACE.

Utility of pre-procedural [99mTc]TcMAA SPECT/CT Multicompartment Dosimetry for Treatment Planning of 90Y Glass microspheres in patients with Hepatocellular Carcinoma: comparison of anatomic versus [99mTc]TcMAA-based Segmentation.

PURPOSE: Pre-treatment [99mTc]TcMAA-based radioembolization treatment planning using multicompartment dosimetry involves the definition of the tumor and normal tissue compartments and calculation of the prescribed absorbed doses. The aim was to compare the real-world utility of anatomic and [99mTc]TcMAA-based segmentation of tumor and normal tissue compartments. MATERIALS AND METHODS: Included patients had HCC treated by glass [90Y]yttrium microspheres, ≥ 1 tumor, ≥ 3 cm diameter and [99mTc]TcMAA SPECT/CT imaging before treatment. Segmentation was performed retrospectively using dedicated dosimetry software: (1) anatomic (diagnostic CT/MRI-based), and (2) [99mTc]TcMAA threshold-based (i.e., using an activity-isocontour threshold). CT/MRI was co-registered with [99mTc]TcMAA SPECT/CT. Logistic regression and Cox regression, respectively, were used to evaluate relationships between total perfused tumor absorbed dose (TAD) and objective response rate (ORR) and overall survival (OS). In a subset-analysis pre- and post-treatment dosimetry were compared using Bland-Altman analysis and Pearson's correlation coefficient. RESULTS: A total of 209 patients were enrolled. Total perfused tumor and normal tissue volumes were larger when using anatomic versus [99mTc]TcMAA threshold segmentation, resulting in lower absorbed doses. mRECIST ORR was higher with increasing total perfused TAD (odds ratio per 100 Gy TAD increase was 1.22 (95% CI: 1.01-1.49; p = 0.044) for anatomic and 1.19 (95% CI: 1.04-1.37; p = 0.012) for [99mTc]TcMAA threshold segmentation. Higher total perfused TAD was associated with improved OS (hazard ratio per 100 Gy TAD increase was 0.826 (95% CI: 0.714-0.954; p = 0.009) and 0.847 (95% CI: 0.765-0.936; p = 0.001) for anatomic and [99mTc]TcMAA threshold segmentation, respectively). For pre- vs. post-treatment dosimetry comparison, the average bias for total perfused TAD was + 11.5 Gy (95% limits of agreement: -227.0 to 250.0) with a strong positive correlation (Pearson's correlation coefficient = 0.80). CONCLUSION: Real-world data support [99mTc]TcMAA imaging to estimate absorbed doses prior to treatment of HCC with glass [90Y]yttrium microspheres. Both anatomic and [99mTc]TcMAA threshold methods were suitable for treatment planning. TRIAL REGISTRATION NUMBER: NCT03295006.

Use of selective internal radiation therapy with yttrium-90 as a bridge to liver resection: a 5-year single-center experience.

BACKGROUND: Selective internal radiation therapy (SIRT) with yttrium-90 (Y-90) has been historically reserved for unresectable liver malignancy. Evidence is emerging for the use of SIRT to increase future liver remnant (FLR), allowing for the resection of previously inoperable disease. METHODS: This was a 5-year retrospective review of all patients undergoing SIRT with Y-90 at a tertiary institute. Patient demographics, clinicopathologic data, surgical details, and postoperative outcomes were reviewed. The primary outcome, safety of liver resection after SIRT, was evaluated with 90-day morbidity and mortality. RESULTS: A total of 134 SIRT procedures were performed on 113 patients. Post-SIRT complications occurred in 18 patients (15.9%), with a single 30-day mortality. In addition, 17 patients underwent SIRT with the intent to augment FLR for liver resection. After SIRT, mean hepatic mebrofenin extraction and FLR increased from 2.5%/min/m2 and 30.5% to 4.2%/min/m2 and 52.5% (P = .01 and P < .0001, respectively). Ten patients underwent resection, and there were 2 intraoperative complications. The median time from SIRT to resection was 5.2 months. The 90-day postoperative morbidity was 20% (n = 2), and complications were analyzed according to the Clavien-Dindo II classification scale. There was no 30-day or 90-day postoperative mortality. CONCLUSION: Post-SIRT liver resection is a challenging procedure with low postoperative mortality and morbidity.

Yttrium-90 (90Y) brachytherapy for squamous carcinoma: Treatment of the conjunctiva, cornea, and sclera.

Purpose: Patients with conjunctival squamous cell carcinoma that present with persisting disease or recurrence following topical chemotherapy and/or surgery especially when invading the sclera are challenging to treat. Herein, we describe the use of high-dose-rate (HDR), FDA-cleared, yttrium-90 (90Y) plaque brachytherapy for such lesions. Observation: Three cases of invasive conjunctival squamous cell carcinoma that had exhibited a poor response or recurrence following topical chemotherapy and/or surgery are described. As treatment, HDR 90Y beta-radiation was applied to the tumor and margins for a single, continuous duration. In contrast to low-dose-rate (LDR) plaque, HDR 90Y brachytherapy did not require episcleral sutures, amniotic membrane buffering of the cornea, a Gunderson flap, outpatient dwell time, or second surgery. Radiation safety was improved by eliminating LDR-implant related post-operative radiation exposure to health care personnel, the community, family, and pets. Follow-up examination at one month revealed complete tumor resolution in all patients. At last follow-up (8, 11 and 18 months) all patients remained clinically tumor-free as confirmed by slit-lamp biomicroscopy, anterior segment optical coherence tomography, and high-frequency ultrasound imaging. There were no acute complications (e.g., corneal edema, iridocyclitis, scleropathy, keratopathy or cataract). Conclusion and Importance: 90Y brachytherapy demonstrated efficacy as a single-surgery, minimally invasive, outpatient irradiation for squamous carcinoma of the ocular surface. While short-term results were promising, long-term follow-up monitoring for side-effects and recurrence are essential.

Voxel-based dosimetry with integrated Y-90 PET/MRI and prediction of response of primary and metastatic liver tumors to radioembolization with Y-90 glass microspheres.

PURPOSE: In this study, we aimed to evaluate the response of the primary and metastatic liver tumors to radioembolization with 90Y glass microspheres and investigate its correlations with dosimetric variables calculated with 90Y PET/MRI. METHODS: In this ambispective study, 44 patients treated with 90Y glass microspheres and imaged with 90Y PET/MRI were included for analysis. Dosimetric analysis was performed for every perfused lesion using dose-volume histograms. Response was assessed by comparing pre-treatment and follow-up total lesion glycolysis (TLG) values derived from 18F-FDG PET imaging. The relationship between ΔTLG and log-transformed dosimetric variables was analyzed with linear mixed effects regression models. ROC analyses were performed to compare discriminatory power of the variables in predicting response and complete response. RESULTS: Regression and ROC analyses demonstrated that mean tumor dose and almost all D values were statistically significant predictors of treatment response and complete treatment response. Specifically, D60, D70 and D80 values exhibited significantly higher discriminatory power for predicting treatment response compared to the mean dose (Dmean) delivered to tumor. High specificity cut-off values to predict response were determined as 160.75 Gy for Dmean, 95.50 Gy for D60, 89 Gy for D70, and 59.50 Gy for D80. Similarly, high-specificity cut-off values to predict complete response were 262.75 Gy for Dmean, 173 Gy for D70, 140.5 Gy for D80, and 100 Gy for D90. CONCLUSION: In this study, we demonstrated that voxel-based dosimetry with post-treatment 90Y PET/MRI can predict response to treatment. D60, D70 and D80 variables also did have greater discriminatory power compared to Dmean in prediction of response. In addition, we present high-specificity cut-offs to predict response (CR + PR) and complete response (CR) for both Dmean and several D variables derived from dose-volume histograms.

Prognostic factors influencing outcomes in hepatocellular carcinoma patients undergoing selective internal radiation therapy.

Selective internal radiation therapy (SIRT) has emerged as a viable endovascular treatment strategy for hepatocellular carcinoma (HCC). According to the Barcelona Clinic Liver Cancer (BCLC) classification, SIRT is currently recommended for early- and intermediate-stage HCC that is unsuitable for alternative locoregional therapies. Additionally, SIRT remains a recommended treatment for patients with advanced-stage HCC and portal vein thrombosis (PVT) without extrahepatic metastasis. Several studies have shown that SIRT is a versatile and promising treatment with a wide range of applications. Consequently, given its favourable characteristics in various scenarios, SIRT could be an encouraging treatment option for patients with HCC across different BCLC stages. Over the past decade, an increasing number of studies have focused on better understanding the prognostic factors associated with SIRT to identify patients who derive the most benefit from this treatment or to refine the optimal technical procedures of SIRT. Several variables can influence treatment decisions, with a growing emphasis on a personalised approach. This review, based on the literature, will focus on the prognostic factors associated with the effectiveness of radioembolization and related complications. By comprehensively analysing these factors, we aimed to provide a clearer understanding of how to optimise the use of SIRT in managing HCC patients, thereby enhancing outcomes across various clinical scenarios.

Paraneoplastic Diarrhea From Medullary Thyroid Carcinoma Resolved With Yttrium-90 Radioembolization of Liver Metastases.

Medullary thyroid carcinoma (MTC) can often have an indolent course despite distant metastatic disease. Additionally, given that metastatic MTC is incurable and systemic therapies have non-negligeable toxicities, localized treatments are often favored in presence of oligo-progressive disease. Transarterial radioembolization (TARE) with yttrium-90 (Y90) has emerged as a safe and efficacious treatment for nonresectable primary and metastatic liver tumors, yet data supporting its use in metastatic MTC are limited. We present the case of a patient with hereditary MTC and large bilobar liver metastases who demonstrated tumor response and resolution of their paraneoplastic diarrhea following TARE with Y90 microspheres.

Transarterial Radioembolization (TARE) Global Practice Patterns: An International Survey by the Cardiovascular and Interventional Radiology Society of Europe (CIRSE).

PURPOSE: An international survey was conducted by the Cardiovascular Interventional Radiological Society of Europe (CIRSE) to evaluate radioembolization practice and capture opinions on real-world clinical and technical aspects of this therapy. MATERIALS AND METHODS: A survey with 32 multiple choice questions was sent as an email to CIRSE members between November and December 2022. CIRSE group member and sister societies promoted the survey to their local members. The dataset was cleaned of duplicates and entries with missing data, and the resulting anonymized dataset was analysed. Data were presented using descriptive statistics. RESULTS: The survey was completed by 133 sites, from 30 countries, spanning 6 continents. Most responses were from European centres (87/133, 65%), followed by centres from the Americas (22/133, 17%). Responding sites had been performing radioembolization for 10 years on average and had completed a total of 20,140 procedures over the last 5 years. Hepatocellular carcinoma treatments constituted 56% of this total, colorectal liver metastasis 17% and cholangiocarcinoma 14%. New sites had opened every year for the past 20 years, indicating the high demand for this therapy. Results showed a trend towards individualized treatment, with 79% of responders reporting use of personalized dosimetry for treatment planning and 97% reporting routine assessment of microsphere distribution post-treatment. Interventional radiologists played an important role in referrals, being present in the referring multi-disciplinary team in 91% of responding centres. CONCLUSION: This survey provides insight into the current state of radioembolization practice globally. The results reveal the increasing significance placed on dosimetry, evolving interventional techniques and increased technology integration.

High-Dose-Rate Yttrium-90 (90Y) Episcleral Plaque Brachytherapy for Iris and Iridociliary Melanoma.

Purpose: To describe a pilot study on the use of single-session, high-dose-rate, Food and Drug Administration-cleared, yttrium-90 (Y90) plaque brachytherapy for iris and iridociliary melanoma. Design: A single-center, clinical case series. Participants: Six consecutive patients were included in this study. Each was diagnosed with an iris or iridociliary melanoma based on clinical examination with or without biopsy. Methods: Each tumor was staged according to the American Joint Committee on Cancer criteria and received Y90 eye plaque brachytherapy. The main variables were tumor size, patient age, sex, and method of diagnosis (clinical or biopsy). Surgical techniques, treatment durations, and ocular side effects were recorded. Local control was defined as a lack of tumor growth or regression determined by clinical examinations, including slit-lamp and gonio photography, as well as high-frequency ultrasound measurements. Toxicity parameters included acute and short-term corneal/scleral change, anterior segment inflammation, and cataract progression. Main Outcome Measures: Local and systemic cancer control, tumor regression, visual acuity, as well as radiation-related normal tissue toxicity. Results: High-dose-rate Y90 plaque brachytherapy was used to treat small (American Joint Committee on Cancer cT1) category melanomas. Single-surgery high-dose-rate irradiations were performed under anesthesia. Because of short treatment durations, high-dose-rate Y90 did not require the additional procedures used for low-dose-rate plaque (e.g., sutures, amniotic membrane epicorneal buffering, Gunderson flaps, and second surgeries for plaque removal). Only conjunctival recession was used to avoid normal tissue irradiation. High-dose-rate Y90 treatment durations averaged 8.8 minutes (median, 7.9; range, 5.8-12.9). High-dose-rate Y90 brachytherapy was associated with no periorbital, corneal (Descemet folds), or conjunctival edema. There was no acute or short-term anterior uveitis, secondary cataract, scleropathy, radiation retinopathy, maculopathy, or optic neuropathy. The follow-up was a mean of 16.0 (range 12-24) months. Evidence of local control included a lack of expansion of tumor borders (n = 6, 100%), darkening with or without atrophy of the tumor surface (n = 5/6, 83%), and a mean 24.5% reduction in ultrasonographically measured tumor thickness. There were no cases of metastatic disease. Conclusions: High-dose-rate Y90 brachytherapy allowed for single-surgery, minimally invasive, outpatient irradiation of iris and iridociliary melanomas. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

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.

Quantitative evaluation of 90Y-PET/CT and 90Y-SPECT/CT-based dosimetry following Yttrium-90 radioembolization.

BACKGROUND: Following yttrium-90 radioembolization (90Y-RE), 90Y-PET/CT and 90Y-SPECT/CT imaging provide the means to calculate the voxelized absorbed dose distribution. Given the widespread use of the two imaging modalities and lack of well-established standardized dosimetry protocols for 90Y-RE, there is a clinical need to systematically investigate and evaluate differences in the performance of voxel-based dosimetry between 90Y-PET/CT and 90Y-SPECT/CT. PURPOSE: To quantitatively analyze and compare 90Y-PET/CT and 90Y-SPECT/CT-based dosimetry following 90Y-RE. METHODS: 90Y-PET/CT and 90Y-SPECT/CT imaging was acquired for 35 patients following 90Y-RE with TheraSphere for the treatment of unresectable hepatocellular carcinoma. Dosimetry was performed using the local deposition method with known activity and the mean dose (Dmean) was calculated for perfused liver volumes (PV), tumors (T), and perfused normal livers (NL). Additionally, the absorbed dose to x% of the volume (Dx, x ∈ $ \in $ [5%, 10%, …, 90%, 95%]) and the volume receiving y Gy (Vy, y ∈ $ \in $ [10 Gy, 20 Gy, …, 190 Gy, 200 Gy]) were calculated for T and NL, respectively. Dose metrics were compared using linear regression, Bland-Altman analysis, and statistical testing. RESULTS: Both 90Y-SPECT/CT and 90Y-PET/CT-based tumor Dmean were strongly correlated (R2 ≥ 0.90) with Dx, excluding metrics on the extrema. Intra-modality comparisons of various Dx and Vy metrics yielded statistically significant differences (ANOVA, p < 0.001) for both90Y-PET/CT and 90Y-SPECT/CT. Based on statistical testing, only Dx metrics separated by greater than 20%-30% coverage, and only Vy metrics separated by greater than 40-70 Gy, reported significant differences. For PV, there was a strong correlation (R2 ≥ 0.99) between Dmean derived separately from 90Y-PET/CT and 90Y-SPECT/CT imaging. The strength of the correlation was slightly reduced for T and NL with R2 = 0.91 and R2 = 0.95, respectively. For PV, the mean bias ± standard error (SE) and 95% limits of agreement (LOA) between Dmean from the two modalities was effectively zero with -0.8 ± 0.4% (± 2.5%). For T and NL, the mean bias ± SE (± LOA) was -14.5 ± 3.7% (± 24%) and 9.4 ± 4.7% (± 27%), respectively. CONCLUSION: The strong correlation between Dmean and Dx suggests information from multiple dose metrics (e.g., D70 and Dmean) is largely redundant when establishing dose-response relationships in 90Y-RE. Dmean is highly correlated between 90Y-PET/CT and 90Y-SPECT/CT-based dosimetry, for all liver VOIs. Relative to 90Y-SPECT/CT, 90Y-PET/CT, on average, yielded higher Dmean to tumors (14%) and lower Dmean to perfused normal livers (9%). Absorbed dose differences for perfused liver volumes between 90Y-SPECT/CT and 90Y-PET/CT were negligible.

A comparison of methods for in vivo activity and absorbed dose quantification with PET/CT following yttrium-90 radioembolization.

BACKGROUND: Yttrium-90 (90Y) positron emission tomography (PET)/computed tomography (CT) imaging is increasingly being used to perform tumor (T) and normal liver (NL) voxel dosimetry after 90Y-radioembolization (90Y-RE). Yet, the accuracy of in vivo 90Y-PET/CT imaging, subject to motion blur and co-registration inaccuracies, and 90Y-PET/CT dose quantification, subject to availability of different voxel dosimetry algorithms, are not well understood. PURPOSE: The purpose of this study was to investigate the accuracy of 90Y-PET/CT-based activity estimates following 90Y-RE and characterize differences between 90Y-PET/CT-based voxel dosimetry algorithms. METHODS: Thirty-five patients underwent 90Y-PET/CT imaging after 90Y-RE with TheraSphere. The net administered 90Y activity (Aadmin) was determined using a dose calibrator and pre- and post-procedure exposure rate measurements. The summation of image-based activity (Aimage) was extracted from perfused volume (PV) and 3D-isotropically 2-cm expanded PV contour (PV+2 cm). Absorbed doses were calculated using voxel S-value (VSV), local deposition method (LDM), and LDM with known activity (LDMKA) dosimetry algorithms. Linear regression and Bland-Altman analysis quantified the relationship between Aimage and Aadmin and between mean dose estimates (DLDM, DVSV, DLDM-KA) for PV, T, and perfused NL volumes. RESULTS: While Aadmin and Aimage in PV were highly correlated (R2 > 0.95), the mean bias ± standard error (SE) and (95% limits of agreement, LOA) was significantly non-zero with -22.7 ± 4.7% (± 28.4%). In PV+2 cm, the mean bias ± SE (± LOA) decreased to 1.3 ± 3.4% (± 18.0%) consistent with zero mean error. DLDM and DVSV were highly correlated (R2 > 0.99) for all volumes of interest (VOIs) and the mean bias ± SE (± LOA) was 2.2 ± 0.2% (± 1.0%), 0.7 ± 0.4% (± 2.8%), and 3.2 ± 0.5% (± 2.8%) for PV, T, and NL, respectively. DLDM-KA and DVSV were correlated with R2 = 0.86, 0.80, and 0.86 for PV, T, and NL, respectively. The mean bias ± SE (± LOA) between DLDM-KA and DVSV was significantly non-zero with -19.6 ± 5.1% (± 31.0%), -20.8 ± 4.4% (± 29.0%), and -18.1 ± 5.3% (± 31.1%) for PV, T, and NL, respectively. CONCLUSIONS: The summation of Aimage in PV was underestimated relative to Aadmin. Only by accounting for respiratory motion, limited spatial resolution, and PET/CT co-registration errors through VOI expansion was Aimage, on average, equal to Aadmin. The differences between DLDM and DVSV were not clinically relevant, though DLDM-KA was approximately 20% greater than DVSV. Given the high quantitative accuracy of dose calibrators and challenges associated with accurate 90Y-PET/CT quantification, LDMKA is the preferred algorithm for accurate 90Y-PET/CT-based dosimetry following 90Y-RE.

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

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

Comparative outcomes of trans-arterial radioembolization in patients with non-alcoholic steatohepatitis/non-alcoholic fatty liver disease-induced HCC: a retrospective analysis.

PURPOSE: Tumorigenesis in NAFLD/NASH-induced HCC is unique and may affect the effectiveness of trans-arterial radioembolization in this population. The purpose of this study was to retrospectively compare the effectiveness of trans-arterial radioembolization for the treatment of hepatocellular carcinoma (HCC) between patients with non-alcoholic steatohepatitis (NASH)/non-alcoholic fatty liver disease (NAFLD) and non-NASH/NAFLD liver disease. MATERIALS AND METHODS: Consecutive patients with HCC who underwent TARE at a single academic institution were retrospectively reviewed. Outcome measures including overall survival (OS), local progression-free survival (PFS), and hepatic PFS as assessed by modified response evaluation criteria in solid tumors (mRECIST) were recorded. Kaplan-Meier and Cox proportional hazard models were utilized to compare progression-free survival and overall survival. RESULTS: 138 separate HCCs in patients treated with TARE between July 2013 and July 2022 were retrospectively identified. Etiologies of HCC included NASH/NAFLD (30/122, 22%), HCV (52/122, 43%), alcoholic liver disease (25/122, 21%), and combined ALD/HCV (14/122, 11%). NASH/NAFLD patients demonstrated a significantly higher incidence of type 2 diabetes mellitus (p < 0.0001). There was no significant difference in overall survival (p = 0.928), local progression-free survival (p = 0.339), or hepatic progression-free survival between the cohorts (p = 0.946) by log-rank analysis. When NASH/NAFLD patients were compared to all combined non-NASH/NAFLD patients, there was no significant difference in OS (HR 1.1, 95% C.I. 0.32-3.79, p = 0.886), local PFS (HR 1.2, 95% C.I. 0.58-2.44, p = 0.639), or hepatic PFS (HR 1.3, 95% C.I. 0.52-3.16, p = 0.595) by log-rank analysis. CONCLUSION: TARE appears to be an equally effective treatment for NASH/NAFLD-induced HCC when compared to other causes of HCC. Further studies in a larger cohort with additional subgroup analyses are warranted.

Imaging Considerations before and after Liver-Directed Locoregional Treatments for Metastatic Colorectal Cancer.

Colorectal cancer is a leading cause of cancer-related death. Liver metastases will develop in over one-third of patients with colorectal cancer and are a major cause of morbidity and mortality. Even though surgical resection has been considered the mainstay of treatment, only approximately 20% of the patients are surgical candidates. Liver-directed locoregional therapies such as thermal ablation, Yttrium-90 transarterial radioembolization, and stereotactic body radiation therapy are pivotal in managing colorectal liver metastatic disease. Comprehensive pre- and post-intervention imaging, encompassing both anatomic and metabolic assessments, is invaluable for precise treatment planning, staging, treatment response assessment, and the prompt identification of local or distant tumor progression. This review outlines the value of imaging for colorectal liver metastatic disease and offers insights into imaging follow-up after locoregional liver-directed therapy.

First Local Experience of Intra-Cavitary Yttrium-90 Citrate Colloid Irradiation via Ommaya Reservoir for Refractory Cystic Craniopharyngioma: a Case Report.

Craniopharyngioma is uncommon benign intracranial tumour that can be cured by surgical resection followed by conventional radiotherapy. However, its anatomical localisation makes the treatment hazardous or impossible. This case report aims to discuss the first local experience of using beta-emitting Yttrium-90 radioisotope in treating a patient with refractory cystic craniopharyngioma. A 43-year-old male who has underlying refractory cystic craniopharyngioma complicated with visual impairment and panhypopituitarism was referred to our nuclear medicine department for intra-cavitary irradiation therapy. Initially, he was presented with blurring of vision and headache which he had two previous resection surgeries of cystic craniopharyngioma. However, due to persistent symptoms, he had Ommaya reservoir shunt inserted for regular aspiration. Despite regular aspiration, his symptoms worsen. He was unsuitable for radiotherapy thus was considered for intra-cystic irradiation with radioisotope. Prior to the therapy, he had pre-therapy assessment with Tc-99 m MAA. He subsequently received Ytrrium-90 citrate colloid of 300 Gy radiation dose to the inner surface of the tumour which complicated with post therapy inflammatory reaction. This first local experience highlights the role of radioisotope as the valuable minimally invasive adjuvant therapy in treating a patient with refractory cystic craniopharyngioma. Further follow-up is necessary to assess the outcome and possible late complications.

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.