Prognostic value of ultra-low-pass whole-genome sequencing of circulating tumor DNA in hepatocellular carcinoma under systemic treatment.

BACKGROUND/AIMS: New prognostic markers are needed to identify patients with hepatocellular carcinoma (HCC) who carry a worse prognosis. Ultra-low-pass whole-genome sequencing (ULP-WGS) (≤0.5× coverage) of cell-free DNA (cfDNA) has emerged as a low-cost promising tool to assess both circulating tumor DNA (ctDNA) fraction and large structural genomic alterations. Here, we studied the performance of ULP-WGS of plasma cfDNA to infer prognosis in patients with HCC. METHODS: Plasma samples were obtained from patients with HCC prior to surgery, locoregional or systemic therapy, and were analyzed by ULP-WGS of cfDNA to an average genome-wide fold coverage of 0.3x. ctDNA and copy number alterations (CNA) were estimated using the software package ichorCNA. RESULTS: Samples were obtained from 73 HCC patients at different BCLC stages (BCLC 0/A: n=37, 50.7%; BCLC B/C: n=36, 49.3%). ctDNA was detected in 18 out of 31 patients who received systemic treatment. Patients with detectable ctDNA showed significantly worse overall survival (median, 13.96 months vs not reached). ctDNA remained an independent predictor of prognosis after adjustment by clinical-pathologic features and type of systemic treatment (hazard ratio 7.69; 95%, CI 2.09-28.27). Among ctDNA-positive patients under systemic treatments, the loss of large genomic regions in 5q and 16q arms was associated with worse prognosis after multivariate analysis. CONCLUSION: ULP-WGS of cfDNA provides clinically relevant information about the tumor biology. The presence of ctDNA and the loss of 5q and 16q arms in ctDNA-positive patients are independent predictors of worse prognosis in patients with advanced HCC receiving systemic therapy.

The Impact of Portal Hypertension Assessment Method on the Outcomes of Hepatocellular Carcinoma Resection: A Meta-Analysis of Matched Cohort and Prospective studies.

OBJECTIVE: Examine PHT impact on postoperative and survival outcomes in HCC patients after LR, specifically exploring distinctions between indirect signs and invasive measurements of PHT. SUMMARY BACKGROUND DATA: PHT has historically discouraged LR in individuals with HCC, due to the elevated risk of morbidity, including liver decompensation (LD). METHODS: A systematic review was conducted using 3 databases to identify prospective controlled and matched cohort studies until December 28, 2022. Focus on comparing postoperative outcomes (mortality, morbidity, and liver-related complications) and OS in HCC patients with and without PHT undergoing LR. Three meta-analysis models were utilized: For aggregated data (fixed-effects inverse variance model), for patient-level survival data (one-stage frequentist meta-analysis with gamma-shared frailty Cox proportional hazards model), and for pooled data (Freeman-Tukey exact and double arcsine method). RESULTS: Nine studies involving 1,124 patients were analyzed. Indirect signs of PHT were not significantly associated with higher mortality, overall complications, PHLF or LD. However, LR in patients with HVPG ≥10 mmHg significantly increased the risk of overall complications, PHLF and LD. Despite elevated risks, the procedure resulted in a 5-year OS rate of 55.2%. Open LR significantly increased the risk of overall complications, PHLF and LD. Conversely, PHT did not show a significant association with worse postoperative outcomes in MILR. CONCLUSIONS: LR with indirect PHT signs poses no increased risk of complications. Yet, in HVPG ≥10 mmHg patients, LR increases overall morbidity and liver-related complications risk. Transjugular HVPG assessment is crucial for LR decisions. MI approach seems to be vital for favorable outcomes, especially in HVPG ≥10 mmHg patients.

Artificial intelligence-based pathology as a biomarker of sensitivity to atezolizumab-bevacizumab in patients with hepatocellular carcinoma: a multicentre retrospective study.

BACKGROUND: Clinical benefits of atezolizumab plus bevacizumab (atezolizumab-bevacizumab) are observed only in a subset of patients with hepatocellular carcinoma and the development of biomarkers is needed to improve therapeutic strategies. The atezolizumab-bevacizumab response signature (ABRS), assessed by molecular biology profiling techniques, has been shown to be associated with progression-free survival after treatment initiation. The primary objective of our study was to develop an artificial intelligence (AI) model able to estimate ABRS expression directly from histological slides, and to evaluate if model predictions were associated with progression-free survival. METHODS: In this multicentre retrospective study, we developed a model (ABRS-prediction; ABRS-P), which was derived from the previously published clustering-constrained attention multiple instance learning (or CLAM) pipeline. We trained the model fit for regression analysis using a multicentre dataset from The Cancer Genome Atlas (patients treated by surgical resection, n=336). The ABRS-P model was externally validated on two independent series of samples from patients with hepatocellular carcinoma (a surgical resection series, n=225; and a biopsy series, n=157). The predictive value of the model was further tested in a series of biopsy samples from a multicentre cohort of patients with hepatocellular carcinoma treated with atezolizumab-bevacizumab (n=122). All samples in the study were from adults (aged ≥18 years). The validation sets were sampled between Jan 1, 2008, to Jan 1, 2023. For the multicentre validation set, the primary objective was to assess the association of high versus low ABRS-P values, defined relative to cross-validation median split thresholds in the first biopsy series, with progression-free survival after treatment initiation. Finally, we performed spatial transcriptomics and matched prediction heatmaps with in situ expression profiles. FINDINGS: Of the 840 patients sampled, 641 (76%) were male and 199 (24%) were female. Across the development and validation datasets, hepatocellular carcinoma risk factors included alcohol intake, hepatitis B and C virus infections, and non-alcoholic steatohepatitis. Using cross-validation in the development series, the mean Pearson's correlation between ABRS-P values and ABRS score (mean expression of ABRS genes) was r=0·62 (SD 0·09; mean p<0·0001, SD<0·0001). The ABRS-P generalised well on the external validation series (surgical resection series, r=0·60 [95% CI 0·51-0·68], p<0·0001; biopsy series, r=0·53 [0·40-0·63], p<0·0001). In the 122 patients treated with atezolizumab-bevacizumab, those with ABRS-P-high tumours (n=74) showed significantly longer median progression-free survival than those with ABRS-P-low tumours (n=48) after treatment initiation (12 months [95% CI 7-not reached] vs 7 months [4-9]; p=0·014). Spatial transcriptomics showed significantly higher ABRS score, along with upregulation of various other immune effectors, in tumour areas with high ABRS-P values versus areas with low ABRS-P values. INTERPRETATION: Our study indicates that AI applied on hepatocellular carcinoma digital slides is able to serve as a biomarker for progression-free survival in patients treated with atezolizumab-bevacizumab. This approach could be used in the development of inexpensive and fast biomarkers for targeted therapies. The combination of AI heatmaps with spatial transcriptomics provides insight on the molecular features associated with predictions. This methodology could be applied to other cancers or diseases and improve understanding of the biological mechanisms that drive responses to treatments. FUNDING: Institut National du Cancer, Fondation ARC, China Scholarship Council, Ligue Contre le Cancer du Val de Marne, Fondation de l'Avenir, Ipsen, and Fondation Bristol Myers Squibb Pour la Recherche en Immuno-Oncologie.

Partial Radiation Nephrectomy Using 90 Y Resin Microspheres: A Treatment Option for Renal Tumors With Malignant Characteristics in Patients Not Candidates for Surgery.

ABSTRACT: Contrast-enhancing renal masses are likely to be malignant in over 90% of cases due to the high diagnostic accuracy of abdominal imaging. In this situation, tumor biopsy is unnecessary and should be managed as a renal cell carcinoma. Resection remains the only potentially curative treatment. However, as in the case herein presented, comorbidities can prevent surgical resection. Radioembolization with 90 Y microspheres is an intra-arterial procedure capable of delivering high doses of radiation to tumors. The present case demonstrates the concept of partial radiation nephrectomy in treating renal tumors with malignant characteristics in patients not amenable to surgery.

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

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

Evaluation of the quality of multiple-choice questions according to the students' academic level.

BACKGROUND: One of the most important challenges in medical education is the preparation of multiple-choice questions able to discriminate between students with different academic level. Average questions may be very easy for students with good performance, reducing their discriminant power in this group of students. The aim of this study was to analyze if the discriminative power of multiple-choice questions is different according to the students' academic performance. METHODS: We retrospectively analyzed the difficulty and discrimination indices of 257 multiple-choice questions used for the end of course examination of pathophysiology and analyzed whether the discrimination indices were lower in students with good academic performance (group 1) than in students with moderate/poor academic performance (group 2). We also evaluated whether case-based questions maintained their discriminant power better than factual questions in both groups of students or not. Comparison of the difficulty and discrimination indices between both groups was based on the Wilcoxon test. RESULTS: Difficulty index was significantly higher in group 1 (median: 0.78 versus 0.56; P <  0.001) and discrimination index was significantly higher in group 2 (median: 0.21 versus 0.28; P <  0.001). Factual questions had higher discriminative indices in group 2 than in group 1 (median: 0.28 versus 0.20; P <  0.001), but discriminative indices of case-based questions did not differ significantly between groups (median: 0.30 versus 0.24; P = 0.296). CONCLUSIONS: Multiple-choice question exams have lower discriminative power in the group of students with high scores. The use of clinical vignettes may allow to maintain the discriminative power of multiple-choice questions.

Nivolumab after selective internal radiation therapy for the treatment of hepatocellular carcinoma: a phase 2, single-arm study.

PURPOSE: To evaluate the safety and efficacy of selective internal radiation therapy (SIRT) in combination with a PD-1 inhibitor in patients with unresectable hepatocellular carcinoma (uHCC) and liver-only disease ineligible for chemoembolization. PATIENTS AND METHODS: NASIR-HCC is a single-arm, multicenter, open-label, phase 2 trial that recruited from 2017 to 2019 patients who were naïve to immunotherapy and had tumors in the BCLC B2 substage (single or multiple tumors beyond the up-to-7 rule), or unilobar tumors with segmental or lobar portal vein invasion (PVI); no extrahepatic spread; and preserved liver function. Patients received SIRT followed 3 weeks later by nivolumab (240 mg every 2 weeks) for up to 24 doses or until disease progression or unacceptable toxicity. Safety was the primary endpoint. Secondary objectives included objective response rate (ORR), time to progression (TTP), and overall survival (OS). RESULTS: 42 patients received SIRT (31 BCLC-B2, 11 with PVI) and were followed for a median of 22.2 months. 27 patients discontinued and 1 never received Nivolumab. 41 patients had any-grade adverse events (AE) and 21 had serious AEs (SAE). Treatment-related AEs and SAEs grade 3-4 occurred in 8 and 5 patients, respectively. Using RECIST 1.1 criteria, ORR reported by investigators was 41.5% (95% CI 26.3% to 57.9%). Four patients were downstaged to partial hepatectomy. Median TTP was 8.8 months (95% CI 7.0 to 10.5) and median OS was 20.9 months (95% CI 17.7 to 24.1). CONCLUSIONS: The combination of SIRT and nivolumab has shown an acceptable safety profile and signs of antitumor activity in the treatment of patients with uHCC that were fit for SIRT. TRIAL REGISTRATION NUMBER: NCT03380130.

Phase I/II Multicenter Trial of a Novel Therapeutic Cancer Vaccine, HepaVac-101, for Hepatocellular Carcinoma.

PURPOSE: Immunotherapy for hepatocellular carcinoma (HCC) shows considerable promise in improving clinical outcomes. HepaVac-101 represents a single-arm, first-in-human phase I/II multicenter cancer vaccine trial for HCC (NCT03203005). It combines multipeptide antigens (IMA970A) with the TLR7/8/RIG I agonist CV8102. IMA970A includes 5 HLA-A*24 and 7 HLA-A*02 as well as 4 HLA-DR restricted peptides selected after mass spectrometric identification in human HCC tissues or cell lines. CV8102 is an RNA-based immunostimulator inducing a balanced Th1/Th2 immune response. PATIENTS AND METHODS: A total of 82 patients with very early- to intermediate-stage HCCs were enrolled and screened for suitable HLA haplotypes and 22 put on study treatment. This consisted in a single infusion of low-dose cyclophosphamide followed by nine intradermal coadministrations of IMA970A and CV8102. Only patients with no disease relapse after standard-of-care treatments were vaccinated. The primary endpoints of the HepaVac-101 clinical trial were safety, tolerability, and antigen-specific T-cell responses. Secondary or exploratory endpoints included additional immunologic parameters and survival endpoints. RESULTS: The vaccination showed a good safety profile. Transient mild-to-moderate injection-site reactions were the most frequent IMA970A/CV8102-related side effects. Immune responses against ≥1 vaccinated HLA class I tumor-associated peptide (TAA) and ≥1 vaccinated HLA class II TAA were respectively induced in 37% and 53% of the vaccinees. CONCLUSIONS: Immunotherapy may provide a great improvement in treatment options for HCC. HepaVac-101 is a first-in-human clinical vaccine trial with multiple novel HLA class I- and class II-restricted TAAs against HCC. The results are initial evidence for the safety and immunogenicity of the vaccine. Further clinical evaluations are warranted.

Pure laparoscopic major liver resection after yttrium90 radioembolization: a case-matched series analysis of feasibility and outcomes.

BACKGROUND: Liver surgery after radioembolization (RE) entails highly demanding and challenging procedures due to the frequent combination of large tumors, severe RE-related adhesions, and the necessity of conducting major hepatectomies. Laparoscopic liver resection (LLR) and its associated advantages could provide benefits, as yet unreported, to these patients. The current study evaluated feasibility, morbidity, mortality, and survival outcomes for major laparoscopic liver resection after radioembolization. MATERIAL AND METHODS: In this retrospective, single-center study patients diagnosed with hepatocellular carcinoma, intrahepatic cholangiocarcinoma or metastases from colorectal cancer undergoing major laparoscopic hepatectomy after RE were identified from institutional databases. They were matched (1:2) on several pre-operative characteristics to a group of patients that underwent major LLR for the same malignancies during the same period but without previous RE. RESULTS: From March 2011 to November 2020, 9 patients underwent a major LLR after RE. No differences were observed in intraoperative blood loss (50 vs. 150 ml; p = 0.621), operative time (478 vs. 407 min; p = 0.135) or pedicle clamping time (90.5 vs 74 min; p = 0.133) between the post-RE LLR and the matched group. Similarly, no differences were observed on hospital stay (median 3 vs. 4 days; p = 0.300), Clavien-Dindo ≥ III complications (2 vs. 1 cases; p = 0.250), specific liver morbidity (1 vs. 1 case p = 1.000), or 90 day mortality (0 vs. 0; p = 1.000). CONCLUSION: The laparoscopic approach for post radioembolization patients may be a feasible and safe procedure with excellent surgical and oncological outcomes and meets the current standards for laparoscopic liver resections. Further studies with larger series are needed to confirm the results herein presented.

Neoantigens as potential vaccines in hepatocellular carcinoma.

BACKGROUND: Neoantigens, new immunogenic sequences arising from tumor mutations, have been associated with response to immunotherapy and are considered potential targets for vaccination. Hepatocellular carcinoma (HCC) is a moderately mutated tumor, where the neoantigen repertoire has not been investigated. Our aim was to analyze whether tumors in HCC patients contain immunogenic neoantigens suitable for future use in therapeutic vaccination. METHODS: Whole-exome sequencing and RNAseq were performed in a cohort of fourteen HCC patients submitted to surgery or liver transplant. To identify mutations, single-nucleotide variants (SNV) originating non-synonymous changes that were confirmed at the RNA level were analyzed. Immunogenicity of putative neoAgs predicted by HLA binding algorithms was confirmed by using in vitro HLA binding assays and T-cell stimulation experiments, the latter in vivo, by immunizing HLA-A*02.01/HLA-DRB1*01 (HHD-DR1) transgenic mice, and in in vitro, using human lymphocytes. RESULTS: Sequencing led to the identification of a median of 1217 missense somatic SNV per patient, narrowed to 30 when filtering by using RNAseq data. A median of 13 and 5 peptides per patient were predicted as potential binders to HLA class I and class II molecules, respectively. Considering only HLA-A*02.01- and HLA-DRB1*01-predicted binders, 70% demonstrated HLA-binding capacity and about 50% were immunogenic when tested in HHD-DR1 mice. These peptides induced polyfunctional T cells that specifically recognized the mutated but not the wild-type sequence as well as neoantigen-expressing cells. Moreover, coimmunization experiments combining CD8 and CD4 neoantigen epitopes resulted in stronger CD8 T cell responses. Finally, responses against neoantigens were also induced in vitro using human cells. CONCLUSION: These results show that mutations in HCC tumors may generate immunogenic neoantigens with potential applicability for future combinatorial therapeutic strategies.

A new animal model of atrophy-hypertrophy complex and liver damage following Yttrium-90 lobar selective internal radiation therapy in rabbits.

Lobar selective internal radiation therapy (SIRT) is widely used to treat liver tumors inducing atrophy of the treated lobe and contralateral hypertrophy. The lack of animal model has precluded further investigations to improve this treatment. We developed an animal model of liver damage and atrophy-hypertrophy complex after SIRT. Three groups of 5-8 rabbits received transportal SIRT with Yttrium 90 resin microspheres of the cranial lobes with different activities (0.3, 0.6 and 1.2 GBq), corresponding to predicted absorbed radiation dose of 200, 400 and 800 Gy, respectively. Another group received non-loaded microspheres (sham group). Cranial and caudal lobes volumes were assessed using CT volumetry before, 15 and 30 days after SIRT. Liver biochemistry, histopathology and gene expression were evaluated. Four untreated rabbits were used as controls for gene expression studies. All animals receiving 1.2 GBq were euthanized due to clinical deterioration. Cranial SIRT with 0.6 GBq induced caudal lobe hypertrophy after 15 days (median increase 34% -ns-) but produced significant toxicity. Cranial SIRT with 0.3 GBq induced caudal lobe hypertrophy after 30 days (median increase 82%, p = 0.04). No volumetric changes were detected in sham group. Transient increase in serum transaminases was detected in all treated groups returning to normal values at 15 days. There was dose-dependent liver dysfunction with bilirubin elevation and albumin decrease. Histologically, 1.2 GBq group developed permanent severe liver damage with massive necrosis, 0.6 and 0.3 GBq groups developed moderate damage with inflammation and portal fibrosis at 15 days, partially recovering at 30 days. There was no difference in the expression of hepatocyte function and differentiation genes between 0.3 GBq and control groups. Cranial SIRT with 0.3 GBq of 90Y resin microspheres in rabbits is a reliable animal model to analyse the atrophy-hypertrophy complex and liver damage without toxicity.

Decreased Long-Term Severe Acute Respiratory Syndrome Coronavirus 2-Specific Humoral Immunity in Liver Transplantation Recipients 12 Months After Coronavirus Disease 2019.

Long-term humoral immunity and its protective role in liver transplantation (LT) patients have not been elucidated. We performed a prospective multicenter study to assess the persistence of immunoglobulin G (IgG) antibodies in LT recipients 12 months after coronavirus disease 2019 (COVID-19). A total of 65 LT recipients were matched with 65 nontransplanted patients by a propensity score including variables with recognized impact on COVID-19. LT recipients showed a lower prevalence of anti-nucleocapsid (27.7% versus 49.2%; P = 0.02) and anti-spike IgG antibodies (88.2% versus 100.0%; P = 0.02) at 12 months. Lower index values of anti-nucleocapsid IgG antibodies were also observed in transplantation patients 1 year after COVID-19 (median, 0.49 [interquartile range, 0.15-1.40] versus 1.36 [interquartile range, 0.53-2.91]; P < 0.001). Vaccinated LT recipients showed higher antibody levels compared with unvaccinated patients (P < 0.001); antibody levels reached after vaccination were comparable to those observed in nontransplanted individuals (P = 0.70). In LT patients, a longer interval since transplantation (odds ratio, 1.10; 95% confidence interval, 1.01-1.20) was independently associated with persistence of anti-nucleocapsid IgG antibodies 1 year after infection. In conclusion, compared with nontransplanted patients, LT recipients show a lower long-term persistence of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. However, SARS-CoV-2 vaccination after COVID-19 in LT patients achieves a significant increase in antibody levels, comparable to that of nontransplanted patients.

Web-based formative assessment through clinical cases: role in pathophysiology teaching.

BACKGROUND: Active learning strategies such as formative assessment through clinical cases may help to get a deeper learning. We have studied the effect of this kind of online formative assessment in pathophysiology teaching. METHODS: Seven brief clinical cases were used to give formative assessment in the first semester of a pathophysiology course. To evaluate its effect on learning, we analyzed the proportion of students that passed the end of semester exam with a score above 60 over 100. We also analyzed the effect of the intervention according to the students' previous academic performance. RESULTS: Ninety-six students participated in the study and sat the exam. Sixty-five of them passed it. Students that passed the exam had a higher previous academic performance and had done a higher number of exercises of formative assessment, both in univariate and multivariate analysis. The participants were divided in three groups, according to their previous academic performance. In the intermediate group, the number of cases done by the students who passed the exam was significantly higher than in those who did not pass it (median: 4 versus 0; P = 0.009). CONCLUSION: Formative assessment through web-based clinical cases was followed by an improvement of the academic results in pathophysiology, mainly in students with intermediate performance.

Changes in humoral immune response after SARS-CoV-2 infection in liver transplant recipients compared to immunocompetent patients.

The protective capacity and duration of humoral immunity after SARS-CoV-2 infection are not yet understood in solid organ transplant recipients. A prospective multicenter study was performed to evaluate the persistence of anti-nucleocapsid IgG antibodies in liver transplant recipients 6 months after coronavirus disease 2019 (COVID-19) resolution. A total of 71 liver transplant recipients were matched with 71 immunocompetent controls by a propensity score including variables with a well-known prognostic impact in COVID-19. Paired case-control serological data were also available in 62 liver transplant patients and 62 controls at month 3 after COVID-19. Liver transplant recipients showed a lower incidence of anti-nucleocapsid IgG antibodies at 3 months (77.4% vs. 100%, p < .001) and at 6 months (63.4% vs. 90.1%, p < .001). Lower levels of antibodies were also observed in liver transplant patients at 3 (p = .001) and 6 months (p < .001) after COVID-19. In transplant patients, female gender (OR = 13.49, 95% CI: 2.17-83.8), a longer interval since transplantation (OR = 1.19, 95% CI: 1.03-1.36), and therapy with renin-angiotensin-aldosterone system inhibitors (OR = 7.11, 95% CI: 1.47-34.50) were independently associated with persistence of antibodies beyond 6 months after COVID-19. Therefore, as compared with immunocompetent patients, liver transplant recipients show a lower prevalence of anti-SARS-CoV-2 antibodies and more pronounced antibody levels decline.

3D voxel-based dosimetry to predict contralateral hypertrophy and an adequate future liver remnant after lobar radioembolization.

INTRODUCTION: Volume changes induced by selective internal radiation therapy (SIRT) may increase the possibility of tumor resection in patients with insufficient future liver remnant (FLR). The aim was to identify dosimetric and clinical parameters associated with contralateral hepatic hypertrophy after lobar/extended lobar SIRT with 90Y-resin microspheres. MATERIALS AND METHODS: Patients underwent 90Y PET/CT after lobar or extended lobar (right + segment IV) SIRT. 90Y voxel dosimetry was retrospectively performed (PLANET Dose; DOSIsoft SA). Mean absorbed doses to tumoral/non-tumoral-treated volumes (NTL) and dose-volume histograms were extracted. Clinical variables were collected. Patients were stratified by FLR at baseline (T0-FLR): < 30% (would require hypertrophy) and ≥ 30%. Changes in volume of the treated, non-treated liver, and FLR were calculated at < 2 (T1), 2-5 (T2), and 6-12 months (T3) post-SIRT. Univariable and multivariable regression analyses were performed to identify predictors of atrophy, hypertrophy, and increase in FLR. The best cut-off value to predict an increase of FLR to ≥ 40% was defined using ROC analysis. RESULTS: Fifty-six patients were studied; most had primary liver tumors (71.4%), 40.4% had cirrhosis, and 39.3% had been previously treated with chemotherapy. FLR in patients with T0-FLR < 30% increased progressively (T0: 25.2%; T1: 32.7%; T2: 38.1%; T3: 44.7%). No dosimetric parameter predicted atrophy. Both NTL-Dmean and NTL-V30 (fraction of NTL exposed to ≥ 30 Gy) were predictive of increase in FLR in patients with T0 FLR < 30%, the latter also in the total cohort of patients. Hypertrophy was not significantly associated with tumor dose or tumor size. When ≥ 49% of NTL received ≥ 30 Gy, FLR increased to ≥ 40% (accuracy: 76.4% in all patients and 80.95% in T0-FLR < 30% patients). CONCLUSION: NTL-Dmean and NTL exposed to ≥ 30 Gy (NTL-V30) were most significantly associated with increase in FLR (particularly among patients with T0-FLR < 30%). When half of NTL received ≥ 30 Gy, FLR increased to ≥ 40%, with higher accuracy among patients with T0-FLR < 30%.

The joint use of 99mTc-MAA-SPECT/CT and cone-beam CT optimizes radioembolization planning.

PURPOSE: To determine which imaging method used during radioembolization (RE) work-up: contrast-enhanced computed tomography (CECT), 99mTc-MAA-SPECT/CT or cone beam-CT (CBCT), more accurately predicts the final target volume (TgV) as well as the influence that each modality has in the dosimetric calculation. METHODS: TgVs from 99mTc-MAA-SPECT/CT, CECT and CBCT were consecutively obtained in 24 patients treated with RE and compared with 90Y PET/CT TgV. Using the TgVs estimated by each imaging modality and a fictitious activity of 1 GBq, the corresponding absorbed doses by tumor and non-tumoral parenchyma were calculated for each patient. The absorbed doses for each modality were compared with the ones obtained using 90Y PET/CT TgV. RESULTS: 99mTc-MAA-SPECT/CT predicted 90Y PET/CT TgV better than CBCT or CECT, even for selective or superselective administrations. Likewise, 99mTc-MAA-SPECT/CT showed dosimetric values more similar to those obtained with 90Y PET/CT. Nevertheless, CBCT provided essential information for RE planning, such as ensuring the total coverage of the tumor and, in cases with more than one feeding artery, splitting the activity according to the volume of tumor perfused by each artery. CONCLUSION: The joint use of 99mTc-MAA-SPECT/CT and CBCT optimizes dosimetric planning for RE procedures, enabling a more accurate personalized approach.

Epidemiological pattern, incidence, and outcomes of COVID-19 in liver transplant patients.

BACKGROUND & AIMS: The incidence and outcomes of coronavirus disease 2019 (COVID-19) in immunocompromised patients are a matter of debate. METHODS: We performed a prospective nationwide study including a consecutive cohort of liver transplant patients with COVID-19 recruited during the Spanish outbreak from 28 February to 7 April, 2020. The primary outcome was severe COVID-19, defined as the need for mechanical ventilation, intensive care, and/or death. Age- and gender-standardised incidence and mortality ratios (SIR and SMR) were calculated using data from the Ministry of Health and the Spanish liver transplant registry. Independent predictors of severe COVID-19 among hospitalised patients were analysed using multivariate Cox regression. RESULTS: A total of 111 liver transplant patients were diagnosed with COVID-19 (SIR = 191.2 [95% CI 190.3-192.2]). The epidemiological curve and geographic distribution overlapped widely between the liver transplant and general populations. After a median follow-up of 23 days, 96 patients (86.5%) were admitted to hospital and 22 patients (19.8%) required respiratory support. A total of 12 patients were admitted to the ICU (10.8%). The mortality rate was 18%, which was lower than in the matched general population (SMR = 95.5 [95% CI 94.2-96.8]). Overall, 35 patients (31.5%) met criteria of severe COVID-19. Baseline immunosuppression containing mycophenolate was an independent predictor of severe COVID-19 (relative risk = 3.94; 95% CI 1.59-9.74; p = 0.003), particularly at doses higher than 1,000 mg/day (p = 0.003). This deleterious effect was not observed with calcineurin inhibitors or everolimus and complete immunosuppression withdrawal showed no benefit. CONCLUSIONS: Being chronically immunosuppressed, liver transplant patients have an increased risk of acquiring COVID-19 but their mortality rates are lower than the matched general population. Upon hospital admission, mycophenolate dose reduction or withdrawal could help in preventing severe COVID-19. However, complete immunosuppression withdrawal should be discouraged. LAY SUMMARY: In liver transplant patients, chronic immunosuppression increases the risk of acquiring COVID-19 but it could reduce disease severity. Complete immunosuppression withdrawal may not be justified. However, mycophenolate withdrawal or temporary conversion to calcineurin inhibitors or everolimus until disease resolution could be beneficial in hospitalised patients.