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Purpose: Unresectable intrahepatic cholangiocarcinoma (ICC) signifies a poor prognosis with limited treatment options beyond systemic chemotherapy. This study's purpose was to evaluate the safety, efficacy, and potential for downstaging to resection of yttrium-90 (Y90) radioembolization for treatment of unresectable ICC. Materials and Methods: From 2004 to 2020, 136 patients with unresectable ICC were treated with radioembolization at a single institution. Retrospective review was performed of a prospectively collected database. Outcomes were (1) biochemical and clinical toxicities, (2) local tumor response, (3) time to progression, and (4) overall survival (OS) after Y90. Univariate/multivariate survival analyses were performed. A subgroup analysis was performed to calculate post-resection recurrence and OS in patients downstaged to resection after Y90. Results: Grade 3+ clinical and biochemical toxicities were 7.6% (n = 10) and 4.9% (n = 6), respectively. Best index lesion response was complete response in 2 (1.5%), partial response in 42 (32.1%), stable disease in 82 (62.6%), and progressive disease in 5 (3.8%) patients. Median OS was 14.2 months. Solitary tumor (P < 0.001), absence of vascular involvement (P = 0.009), and higher serum albumin (P < 0.001) were independently associated with improved OS. Eleven patients (8.1%) were downstaged to resection and 2 patients (1.5%) were bridged to transplant. R0-resection was achieved in 8/11 (72.7%). Post-resection median recurrence and OS were 26.3 months and 39.9 months, respectively. Conclusion: Y90 has an acceptable safety profile and high local disease control rates for the treatment of unresectable ICC. Downstaging to resection with > 3 years survival supports the therapeutic role of Y90 for unresectable ICC. Level of Evidence: Level 3, single-arm single-center cohort study. [ABSTRACT FROM AUTHOR]

Purpose: To perform precision dosimetry in yttrium-90 radioembolization through CT imaging of radiopaque microspheres in a rabbit liver model and to compare extracted dose metrics to those produced from conventional PET-based dosimetry. Materials and methods: A CT calibration phantom was designed containing posts with nominal microsphere concentrations of 0.5 mg/mL, 5.0 mg/mL, and 25.0 mg/mL. The mean Hounsfield unit was extracted from the post volumes to generate a calibration curve to relate Hounsfield units to microsphere concentration. A nominal bolus of 40 mg of microspheres was administered to the livers of eight rabbits, followed by PET/CT imaging. A CT-based activity distribution was calculated through the application of the calibration curve to the CT liver volume. Post-treatment dosimetry was performed through the convolution of yttrium-90 dose-voxel kernels and the PET- and CT-based cumulated activity distributions. The mean dose to the liver in PET- and CT-based dose distributions was compared through linear regression, ANOVA, and Bland–Altman analysis. Results: A linear least-squares fit to the average Hounsfield unit and microsphere concentration data from the calibration phantom confirmed a strong correlation (r2 > 0.999) with a slope of 14.13 HU/mg/mL. A poor correlation was found between the mean dose derived from CT and PET (r2 = 0.374), while the ANOVA analysis revealed statistically significant differences (p < 10−12) between the MIRD-derived mean dose and the PET- and CT-derived mean dose. Bland–Altman analysis predicted an offset of 15.0 Gy between the mean dose in CT and PET. The dose within the liver was shown to be more heterogeneous in CT than in PET with an average coefficient of variation equal to 1.99 and 1.02, respectively. Conclusion: The benefits of a CT-based approach to post-treatment dosimetry in yttrium-90 radioembolization include improved visualization of the dose distribution, reduced partial volume effects, a better representation of dose heterogeneity, and the mitigation of respiratory motion effects. Post-treatment CT imaging of radiopaque microspheres in yttrium-90 radioembolization provides the means to perform precision dosimetry and extract accurate dose metrics used to refine the understanding of the dose–response relationship, which could ultimately improve future patient outcomes. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Precision dosimetry in yttrium-90 radioembolization through CT imaging of radiopaque microspheres in a rabbit liver model." The correction adds James J. Karnia from the Department of Veterinary Medicine and Surgery at the University of Missouri to the list of authors. It also revises the Authors' Contributions section to include the specific roles and contributions of each author. The original article has been updated accordingly. The publisher, Springer Nature, maintains a neutral stance on jurisdictional claims and institutional affiliations. [Extracted from the article]

Purpose: Portal vein embolization (PVE) is an established neoadjuvant method to induce future liver remnant hypertrophy prior to surgical resection of hepatic tumors. The purpose of our study was to examine the feasibility of PVE with glass 90Y microspheres (Y90 PVE) in Sprague-Dawley rats. We tested the hypothesis that increased doses of Y90 PVE would increase target lobe fibrosis and atrophy.Methods: Twenty-two rats were assigned to four groups for Y90 PVE to the right median lobe: very high- (273.8 MBq; n = 2), high- (99.9 MBq; n = 10), medium- (48.1 MBq; n = 5), and low-dose (14.8 MBq; n = 5). An untreated control group included seven rats. 90Y PET/CT of 90Y distributions confirmed lobar targeting. MRI volumes were measured at baseline, 2-, 4-, 8- and 12-weeks. Explanted hepatic lobes were weighed, sectioned, and stained for H&E and immunohistochemistry. Digitized slides allowed quantitative measurements of fibrosis (20 foci/slide).Results: Ex vivo measurements confirmed 91-97% activity was localized to the target lobe (n = 4). The percent growth of the target lobe relative to baseline was - 5.0% (95% CI - 17.0-6.9%) for high-, medium dose rats compared to + 18.6% (95% CI + 7.6-29.7%) in the low-dose group at 12-weeks (p = 0.0043). Radiation fibrosis increased in a dose-dependent fashion. Fibrotic area/microsphere was 22,893.5, 14,946.2 ± 2253.3, 15,304.5 ± 4716.6, and 5268.8 ± 2297.2 μm2 for very high- (n = 1), high- (n = 4), medium- (n = 3), and low-dose groups (n = 5), respectively.Conclusion: Y90 PVE was feasible in the rat model, resulted in target lobe atrophy, and dose-dependent increases in hepatic fibrosis at 12 weeks. The onset of imaging-based volumetric changes was 8-12 weeks. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the combination of 90Y radioembolization (Y90) and drug-eluting bead irinotecan (DEBIRI) microspheres in the VX2 rabbit model. Materials and Methods: An initial dose finding study was performed in 6 White New Zealand rabbits to identify a therapeutic but subcurative dose of Y90. In total, 29 rabbits were used in four groups: Y90 treatment (n = 8), DEBIRI treatment (n = 6), Y90 + DEBIRI treatment (n = 7), and an untreated control group (n = 8). Hepatic toxicity was evaluated at baseline, 24 h, 72 h, 1 week, and 2 weeks. MRI tumor volume (TV) and enhancing tumor volume were assessed baseline and 2 weeks. Tumor area and necrosis were evaluated on H&E for pathology. Results: Infused activities of 84.0–94.4 MBq (corresponding to 55.1–72.7 Gy) were selected based on the initial dose finding study. Infusion of DEBIRI after Y90 was technically feasible in all cases (7/7). Overall, 21/29 animals survived to 2 weeks, and the remaining animals had extrahepatic disease on necropsy. Liver transaminases were elevated with Y90, DEBIRI, and Y90 + DEBIRI compared to control at 24 h, 72 h, and 1 week post-treatment and returned to baseline by 2 weeks. By TV, Y90 + DEBIRI was the only treatment to show statistically significant reduction at 2 weeks compared to the control group (p = 0.012). The change in tumor volume (week 2—baseline) for both Y90 + DEBIRI versus control (p = 0.002) and Y90 versus control (p = 0.014) was significantly decreased. There were no statistically significant differences among groups on pathology. Conclusion: Intra-arterial Y90 + DEBIRI was safe and demonstrated enhanced antitumor activity in rabbit VX2 tumors. This combined approach warrants further investigation. [ABSTRACT FROM AUTHOR]

Purpose: To identify baseline characteristics and long-term prognostic factors in non-transplant patients with unresectable hepatocellular carcinoma (HCC) who had prolonged survival after treatment with yttrium-90 radioembolization (Y90).Materials and Methods: Sixty-seven "Super Survivors" (defined as ≥ 3-year survival after Y90) were identified within our 1000-patient Y90 database (2003-2017). Baseline imaging and follow-up occurred at 1 month and every 3 months thereafter. Overall survival (OS) was calculated with Kaplan-Meier estimates with log-rank test in subgroups: Child-Pugh (CP) score, distribution of disease, portal vein thrombus (PVT), and technique (segmental vs lobar Y90).Results: Median age 69.5 years (range 45-94 years); 69% male; 60% solitary HCC; 79% unilobar disease; 12% PVT; 10% ascites; Barcelona Clinic Liver Cancer Stage A-54%/B-28%/C-16%/D-2%; CP A-70%/B-28%/C-2%. Longest baseline tumor diameter was 5.4 ± 4.0 cm (mean ± SD). All patients had an imaging response (either partial or complete response). Median OS was 67.5 months (95% CI 55.2-82.5). CP score and main PVT stratified median OS (p = 0.0007 and p = 0.0187, respectively). Beyond 3 years, segmental versus lobar Y90 was associated with improved OS with a median OS of 80.2 versus 46.7 months, respectively (p = 0.0024). Dosing > 200 Gy was not a significant predictor of improved OS.Conclusions: Super Survivors spanning the BCLC staging system maintained durable OS after radioembolization that was stratified by the extent of underlying liver disease. The common variable among all patients was an imaging response. Segmental versus lobar Y90 may have a long-term associated OS benefit. [ABSTRACT FROM AUTHOR]

Computers, both large and small, can be of great assistance to a field worker. This assistance falls mainly in the area of relieving the field worker from tedious mechanical phases such as typing, sorting. and retrieving information. An examination of field work methods identifies issues and problems which must be addressed by any system for undertaking field work. A rationale for a "loose and in clusive" (as opposed to an exhaustive and mutually exclusive) coding system is presented. Efficiency, confidentiality, data reduction, and flexibility of testing propositions are discussed as criteria for assessing any system which facilitates field work. The papa concludes by contrasting the methods previously used to collect data, reduce its bulk, code, and retrieve information with what is possible with todays computer hardware and software, and with what will be possible in the near future. [ABSTRACT FROM AUTHOR]