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2818 citation(s) found for "C, Liu".

Human Immunodeficiency Virus (HIV) Status Drives Diffuse Large B Cell Lymphoma through Oncogenic Signaling Pathways
Maguire, Alanna , Fogel, Gary B. , Liu, Enoch S., Wisner, Lee, Ramsower, Colleen , Glinsmann‐Gibson, Betty, Lamers, Susanna L. , McGrath, Michael S. , Maguire, Alanna , Maguire, Alanna , Kendrick, Samantha , Rimsza, Lisa M.

Blood | July 28, 2022 | Volume: 130 | Issue: Suppl_1 | Pages: 5128-5128

10.1182/blood.v130.suppl_1.5128.5128 Get It

Abstract Introduction: Diffuse Large B cell Lymphoma (DLBCL) is up to 80-fold more likely to occur and follows a more aggressive clinical course in HIV positive (+) individuals compared to HIV negative (-) individuals. Moreover, the vast majority frequently present at advanced stages with high tumor burdens with poor prognosis. The molecular pathology underpinning the clinical features of DLBCL in HIV(+) patients relative to the general population is poorly understood; however, it is suspected to depend on decreased host immune surveillance and alternative mechanisms of tumorogenesis. In this study, we sought to identify the differences in gene expression between HIV(+) and HIV(-) DLBCL cohorts that may contribute to the unique features of HIV(+) DLBCL. Methods: We performed a retrospective gene expression profiling (GEP) study using a total of 70 DLBCL cases, 31 HIV(+) obtained from AIDS Cancer Specimen Resource Network (https://acsr.ucsf.edu/) and 39 HIV(-) institutional cases. The H&Es for all cases were reviewed by a hematopathologist and tumor content determined. Cases that did not meet the minimum tumor content threshold of 70% were macro-dissected. RNA was extracted from 4x 5µm formalin fixed, paraffin embedded (FFPE) sections using the Qiagen AllPrep DNA/RNA FFPE Kit and quantified using a NanoDrop. The Lymph2Cx assay, which accurately subtypes DLBCL in FFPE tissues (Scott et al 2014), was used to determine the cell of origin (COO) subtypes: Germinal Center B cell (GCB), Activated B cell (ABC) and Unclassifiable (UNC). Digital GEP was performed using the NanoString PanCancer Pathways and Immunology panels, targeting a total of over 1300 genes with known roles in cancer or immune signaling. Results: Of the 31 HIV(+) cases, Lymph2Cx subtyping showed 74% (23/31) were GCB, 13% (4/31) were ABC and 13% (4/31) were UNC. In a similar distribution to the HIV(+), and comparable to prior literature, 54% (21/39) of HIV(-) cases were GCB, 31% (12/39) were ABC and 15% (6/39) were UNC. Differential gene expression was observed between HIV(+) and HIV(-) cases, but no association with COO subtype was found. When the data was re-analyzed within the GCB subtype alone, stratification by HIV status was observed. Particularly, reduced expression of genes associated with immune regulation was observed in HIV(+) GCB cases compared to HIV(-) GCB cases. In contrast, expression of genes associated with cell cycle regulation and homologous recombination (the predominate double stranded DNA repair pathway employed during the cell cycle), were higher in HIV(+) cases compared to HIV(-) GCB cases. Conclusions: The results show, that within the GCB subtype, marked differences in gene expression are associated with HIV status. Our results suggest that the aggressive nature of DLBCL in HIV(+) patients may, in part, be mediated by enhanced cell proliferation potentiated by aberrant DNA repair. Disclosures Fogel: Natural Selection Inc: Employment. Liu: Natural Selection Inc: Employment. Lamers: Bioinfoexperts LLC: Employment.
Elevated plasma homocysteine level is associated with poor ST-segment resolution in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention at high altitude
Liu, Bei , Yang, Lixia , Guo, Ruiwei , Yang, Shujuan , Zhang, Bin , Guo, Ruiwei

Cardiology Plus | July 27, 2022 | Volume: 7 | Issue: 2 | Pages: 92-96

10.1097/cp9.0000000000000016 Get It

Abstract Background and purpose: Poor ST-segment resolution (STR) is strongly associated with poor prognosis in patients with ST segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). previous studies suggested higher HCY level in the people who live in high altitudes, so a retrospective analysis is conducted to examine the potential relationship between elevated serum HCY and poor STR after PPCI at high altitudes. Methods: This retrospective analysis included 308 high-altitude dwelling patients (1800-2200 meters elevation from the sea level) undergoing PPCI for STEMI during a period from September 2021 to March 2022. Clinical data were collected and statistically analyzed. Results: In comparison to the patients with normal plasma homocysteine (≤15 mmol/L; n = 155), patients with elevated homocysteine (>15 mmol/L) had higher percentage of men (92.81% vs. 80.00%; p = 0.001) and smoker (79.08% vs. 63.87%; p = 0.003), but no difference in other key baseline characteristics. The rate of complete ST-segment resolution after PPCI (≥ 70%) was 83.23% in the control group and 49.67% in the elevated HCY group (p ≤ 0.001). In multivariable regression analysis, poor ST-segment resolution (<70%) was independently associated with longer pain-to-balloon time (OR 0.832; 95%CI: 0.775–0.894), lower uric acid (OR 1.003; 95%CI: 1.000-1.005), and elevated HCY (OR 0.957 vs. normal HCY; 95%CI: 0.937–0.977). Conclusion: Elevated plasma HCY level was associated with poor ST segment resolution in patients undergoing PPCI STEMI at high altitude.
Liver Transplantation as a New Standard of Care in Patients With Perihilar Cholangiocarcinoma? Results From an International Benchmark Study
Breuer, Eva , Doyle, Majella B. , Yang, Liu , Anwar, Imran J. , Merani, Shaheed , Limkemann, Ashley , Jeddou, Heithem , Kim, Steven C. , Nassar, Ahmed , Vibert, Éric , Oliveira, Michelle, Cherqui, Daniel , Porte, Robert J. , Magliocca, Joseph F. , Fischer, Lutz , Zieniewicz, Krzysztof , Ramı́rez, Pablo , Foley, David P. , Langnas, Alan N. , Polak, Wojciech G. , Rosen, Charles B. , Dutkowski, Philipp , Clavien, Pierre‐Alain , Chapman, William C. , Taner, C. Burcin , Clavien, Pierre-Alain , Chapman, William C , Polak, Wojciech G , Mueller, Matteo , Murad, Sarwa Darwish , López‐López, Víctor , Hoogwater, Frederik J.H. , Fondevila, Constantino , Boudjéma, Karim , Schenk, Austin D. , Knechtle, Stuart J. , Chapman, William C. , Gores, Gregory J. , Heimbach, Julie K.

Annals of Surgery | July 27, 2022 | Volume: 276 | Issue: 5 | Pages: 846-853

10.1097/sla.0000000000005641 | PMID 35894433 Get It

Objective: To define benchmark values for liver transplantation (LT) in patients with perihilar cholangiocarcinoma (PHC) enabling unbiased comparisons. Background: Transplantation for PHC is used with reluctance in many centers and even contraindicated in several countries. Although benchmark values for LT are available, there is a lack of specific data on LT performed for PHC. Methods: PHC patients considered for LT after Mayo-like protocol were analyzed in 17 reference centers in 2 continents over the recent 5-year period (2014–2018). The minimum follow-up was 1 year. Benchmark patients were defined as operated at high-volume centers (≥50 overall LT/year) after neoadjuvant chemoradiotherapy, with a tumor diameter <3 cm, negative lymph nodes, and with the absence of relevant comorbidities. Benchmark cutoff values were derived from the 75th to 25th percentiles of the median values of all benchmark centers. Results: One hundred thirty-four consecutive patients underwent LT after completion of the neoadjuvant treatment. Of those, 89.6% qualified as benchmark cases. Benchmark cutoffs were 90-day mortality ≤5.2%; comprehensive complication index at 1 year of ≤33.7; grade ≥3 complication rates ≤66.7%. These values were better than benchmark values for other indications of LT. Five-year disease-free survival was largely superior compared with a matched group of nodal negative patients undergoing curative liver resection (n=106) (62% vs 32%, P<0.001). Conclusion: This multicenter benchmark study demonstrates that LT offers excellent outcomes with superior oncological results in early stage PHC patients, even in candidates for surgery. This provocative observation should lead to a change in available therapeutic algorithms for PHC.
Investigation of beam delivery time for synchrotron-based proton pencil beam scanning system with novel scanning mode
Liang, Xiaoying , Liu, Chunbo , Shen, Jiajian , Bues, Martin , Dougherty, Jingjing M. , Parisi, Alessio , Shrestha, Deepak K. , Yaddanpudi, Sridhar, Beltran, Chris , Yaddanapudi, Sridhar , Furutani, Keith M. , Shen, Jiajian , Bues, Martin , Dougherty, Jingjing M , Parisi, Alessio , Beltran, Chris J , Liang, Xiaoying , Yaddanapudi, Sridhar , Li, Heng

Physics in Medicine & Biology | July 25, 2022 | Volume: 67 | Issue: 17 | Pages: 175001

10.1088/1361-6560/ac8410 | PMID 35878611 Get It

Abstract Objective. To investigate synchrotron-based proton pencil beam scanning (PBS) beam delivery time (BDT) using novel continuous scanning mode. Approach. A BDT calculation model was developed for the Hitachi particle therapy system. The model was validated against the measured BDT of 36 representative clinical proton PBS plans with discrete spot scanning (DSS) in the current Hitachi proton therapy system. BDTs were calculated with the next generation using Mayo Clinic Florida system operating parameters for conventional DSS, and novel dose driven continuous scanning (DDCS). BDTs of DDCS with and without Break Spots were investigated. Main results. For DDCS without Break Spots, the use of Stop Ratio to control the transit dose largely reduced the beam intensity and consequently, severely prolonged the BDT. DDCS with Break Spots was able to maintain a sufficiently high beam intensity while controlling transit dose. In DDCS with Break Spots, tradeoffs were made between beam intensity and number of Break Spots. Therefore, BDT decreased with increased beam intensity but reached a plateau for beam intensity larger than 10 MU s −1 . Averaging over all clinical plans, BDT was reduced by 10% for DDCS with Break Spots compared to DSS. Significance. DDCS with Break Spots reduced BDT. DDCS has the potential to further reduce BDT under the ideal scenario which requests both stable beam intensity extraction and accurately modelling the transit dose. Further investigation is warranted.
A Primer Genetic Toolkit for Exploring Mitochondrial Biology and Disease Using Zebrafish
Sabharwal, Ankit , Campbell, Jarryd M. , Schwab, Tanya L., WareJoncas, Zachary , Wishman, Mark , Ata, Hirotaka , Liu, Wiebin, Hunter, Danielle E., Bergren, Jake D., Urban, Mark D. , Urban, Rhianna , Holmberg, Shannon R. , Kar, Bibekananda , Ekker, Stephen C. , Wishman, Mark D, Ichino, Noriko , Urban, Mark D , Kar, Bibekananda , Cook, Alex, Ding, Yonghe , Ekker, Stephen C , Sabharwal, Ankit , Cook, Alex Richard , Xu, Xiaolei , Clark, Karl J.

Genes | July 24, 2022 | Volume: 13 | Issue: 8 | Pages: 1317

10.3390/genes13081317 | PMID 35893052 Get It

Mitochondria are a dynamic eukaryotic innovation that play diverse roles in biology and disease. The mitochondrial genome is remarkably conserved in all vertebrates, encoding the same 37-gene set and overall genomic structure, ranging from 16,596 base pairs (bp) in the teleost zebrafish (Danio rerio) to 16,569 bp in humans. Mitochondrial disorders are amongst the most prevalent inherited diseases, affecting roughly 1 in every 5000 individuals. Currently, few effective treatments exist for those with mitochondrial ailments, representing a major unmet patient need. Mitochondrial dysfunction is also a common component of a wide variety of other human illnesses, ranging from neurodegenerative disorders such as Huntington’s disease and Parkinson’s disease to autoimmune illnesses such as multiple sclerosis and rheumatoid arthritis. The electron transport chain (ETC) component of mitochondria is critical for mitochondrial biology and defects can lead to many mitochondrial disease symptoms. Here, we present a publicly available collection of genetic mutants created in highly conserved, nuclear-encoded mitochondrial genes in Danio rerio. The zebrafish system represents a potentially powerful new opportunity for the study of mitochondrial biology and disease due to the large number of orthologous genes shared with humans and the many advanced features of this model system, from genetics to imaging. This collection includes 15 mutant lines in 13 different genes created through locus-specific gene editing to induce frameshift or splice acceptor mutations, leading to predicted protein truncation during translation. Additionally, included are 11 lines created by the random insertion of the gene-breaking transposon (GBT) protein trap cassette. All these targeted mutant alleles truncate conserved domains of genes critical to the proper function of the ETC or genes that have been implicated in human mitochondrial disease. This collection is designed to accelerate the use of zebrafish to study many different aspects of mitochondrial function to widen our understanding of their role in biology and human disease.
Development of Parkinson Disease and Its Relationship with Incidentally Discovered White Matter Disease and Covert Brain Infarction in a Real‐World Cohort
Kent, David M. , Leung, Lester Y. , Puttock, Eric J. , Kallmes, David F. , Nelson, Jason , Vickery, Ellen M. , Chen, Wansu , Noyce, Alastair J , Kent, David M , Wang, Andy Yu-Der , Luetmer, Patrick H. , Fu, Sunyang , Zheng, Chengyi , Liu, Hongfang , Noyce, Alastair J.

Annals of Neurology | July 22, 2022 | Volume: 92 | Issue: 4 | Pages: 620-630

10.1002/ana.26458 | PMID 35866711 Get It

Objective This study aimed to examine the relationship between covert cerebrovascular disease, comprised of covert brain infarction and white matter disease, discovered incidentally in routine care, and subsequent Parkinson disease. Methods Patients were ≥50 years and received neuroimaging for non‐stroke indications in the Kaiser Permanente Southern California system from 2009 to 2019. Natural language processing identified incidentally discovered covert brain infarction and white matter disease and classified white matter disease severity. The Parkinson disease outcome was defined as 2 ICD diagnosis codes. Results 230,062 patients were included (median follow‐up 3.72 years). A total of 1,941 Parkinson disease cases were identified (median time‐to‐event 2.35 years). Natural language processing identified covert cerebrovascular disease in 70,592 (30.7%) patients, 10,622 (4.6%) with covert brain infarction and 65,814 (28.6%) with white matter disease. After adjustment for known risk factors, white matter disease was associated with Parkinson disease (hazard ratio 1.67 [95%CI, 1.44, 1.93] for patients <70 years and 1.33 [1.18, 1.50] for those ≥70 years). Greater severity of white matter disease was associated with increased incidence of Parkinson disease(/1,000 person‐years), from 1.52 (1.43, 1.61) in patients without white matter disease to 4.90 (3.86, 6.13) in those with severe disease. Findings were robust when more specific definitions of Parkinson disease were used. Covert brain infarction was not associated with Parkinson disease (adjusted hazard ratio = 1.05 [0.88, 1.24]). Interpretation Incidentally discovered white matter disease was associated with subsequent Parkinson disease, an association strengthened with younger age and increased white matter disease severity. Incidentally discovered covert brain infarction did not appear to be associated with subsequent Parkinson disease. ANN NEUROL 2022;92:620–630
ACE2 and TMPRSS2 SARS-CoV-2 infectivity genes: deep mutational scanning and characterization of missense variants
Zhang, Lingxin , Sarangi, Vivekananda , Liu, Duan , Ho, Ming‐Fen , Grassi, Angela R, Moon, Irene, Larson, Nicholas B. , Athreya, Arjun P. , Wang, Liewei , Weinshilboum, Richard M. , Larson, Nicholas B , Weinshilboum, Richard, Liu, Duan , Ho, Ming-Fen , Wei, Lixuan , Vierkant, Robert A. , Lazaridis, Konstantinos N. , Weinshilboum, Richard M.

Human Molecular Genetics | July 21, 2022 | Volume: 31 | Issue: 24 | Pages: 4183-4192

10.1093/hmg/ddac157 | PMID 35861636 Get It

Abstract The human angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) proteins play key roles in the cellular internalization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the coronavirus responsible for the coronavirus disease of 2019 (COVID-19) pandemic. We set out to functionally characterize the ACE2 and TMPRSS2 protein abundance for variant alleles encoding these proteins that contained non-synonymous single-nucleotide polymorphisms (nsSNPs) in their open reading frames (ORFs). Specifically, a high-throughput assay, deep mutational scanning (DMS), was employed to test the functional implications of nsSNPs, which are variants of uncertain significance in these two genes. Specifically, we used a ‘landing pad’ system designed to quantify the protein expression for 433 nsSNPs that have been observed in the ACE2 and TMPRSS2 ORFs and found that 8 of 127 ACE2, 19 of 157 TMPRSS2 isoform 1 and 13 of 149 TMPRSS2 isoform 2 variant proteins displayed less than ~25% of the wild-type protein expression, whereas 4 ACE2 variants displayed 25% or greater increases in protein expression. As a result, we concluded that nsSNPs in genes encoding ACE2 and TMPRSS2 might potentially influence SARS-CoV-2 infectivity. These results can now be applied to DNA sequence data for patients infected with SARS-CoV-2 to determine the possible impact of patient-based DNA sequence variation on the clinical course of SARS-CoV-2 infection.
Respiratory mucosal immunity against SARS-CoV-2 after mRNA vaccination
Tang, Jinyi , Zeng, Cong , Cox, Thomas M, Li, Chaofan , Son, Young Min , Cheon, In Su , Wu, Yue , Taylor, Justin J. , Chakaraborty, Rana, Johnson, Aaron J. , Schiavo, Dante , Utz, James P., Reisenauer, Janani , Midthun, David E. , Mullon, John J., Edell, Eric S. , Alameh, Mohamad‐Gabriel , Borish, Larry , Teague, W. Gerald , Kaplan, Mark H. , Kern, Ryan , Vassallo, Robert , Behl, Supriya, Taylor, Justin J , Chakraborty, Rana , Johnson, Aaron J. , Reisenauer, Janani S , Midthun, David E , Kaplan, Mark H , Weissman, Drew , Kern, R , Hu, Haitao , Vassallo, Robert , Liu, Shan-Lu , Sun, Jie , Tang, J , Li, Chaofan , Behl, Supriya , Chakaraborty, Rana, Liu, Shan-Lu , Sun, Jie

Science Immunology | July 19, 2022 | Volume: 7 | Issue: 76 | Pages: No page available

10.1126/sciimmunol.add4853 | PMID 35857583 Get It

SARS-CoV-2 mRNA vaccination induces robust humoral and cellular immunity in the circulation; however, it is currently unknown whether it elicits effective immune responses in the respiratory tract, particularly against variants of concern (VOCs), including Omicron. We compared the SARS-CoV-2 S–specific total and neutralizing antibody responses, and B and T cell immunity, in the bronchoalveolar lavage fluid (BAL) and blood of COVID-19–vaccinated individuals and hospitalized patients. Vaccinated individuals had significantly lower levels of neutralizing antibody against D614G, Delta (B.1.617.2), and Omicron BA.1.1 in the BAL compared with COVID-19 convalescents despite robust S-specific antibody responses in the blood. Furthermore, mRNA vaccination induced circulating S-specific B and T cell immunity, but in contrast to COVID-19 convalescents, these responses were absent in the BAL of vaccinated individuals. Using a mouse immunization model, we demonstrated that systemic mRNA vaccination alone induced weak respiratory mucosal neutralizing antibody responses, especially against SARS-CoV-2 Omicron BA.1.1 in mice; however, a combination of systemic mRNA vaccination plus mucosal adenovirus-S immunization induced strong neutralizing antibody responses not only against the ancestral virus but also the Omicron BA.1.1 variant. Together, our study supports the contention that the current COVID-19 vaccines are highly effective against severe disease development, likely through recruiting circulating B and T cell responses during reinfection, but offer limited protection against breakthrough infection, especially by the Omicron sublineage. Hence, mucosal booster vaccination is needed to establish robust sterilizing immunity in the respiratory tract against SARS-CoV-2, including infection by the Omicron sublineage and future VOCs.
Influence of endurance sports on atrial fibrillation ablation outcomes
Liu, Michael B. , Lee, Justin Z. , Klooster, Lindsay, Petty, Skye A. Buckner, Scott, Luis R. , Buckner Petty, Skye A, Liu, Michael

Journal of Arrhythmia | July 15, 2022 | Volume: 38 | Issue: 5 | Pages: 694-709

10.1002/joa3.12746 | PMID 36237855 Get It

AbstractObjectivesWe aimed to investigate the outcomes of pulmonary vein isolation in athletes.MethodsWe retrospectively identified endurance athletes who underwent catheter ablation at our institution (2004–2018). Endurance athletes were defined as participating in competitive athletics for at least 1500 lifetime hours in sports at the IB or IIA Bethesda classification or higher. Primary endpoints were freedom from atrial arrhythmias at 12, 24, and 36 months after the procedure. Secondary endpoints were defined as qualitative improvement in symptoms allowing athletes to return to their previous level of activity. Athletes were compared with a control group of nonathletes in a 3‐to‐1 matched analysis by age and sex.ResultsA total of 39 endurance athletes who underwent catheter ablation were identified during the study period. At 12 months, there was no difference in treatment outcomes for athletes versus nonathletes (relative risk [RR], 1.06; 95% CI, 0.92–1.22; p = .40). Freedom from atrial arrhythmias was 35% less likely in athletes than nonathletes at 24 months (RR, 0.65; 95% CI, 0.50–0.83; p < .001) and 42% less likely at 36 months (RR, 0.58; 95% CI, 0.41–0.79; p < .001). Overall, 77% of the athletes were able to return to their previous level of activity following catheter ablation.ConclusionEndurance athletes with atrial fibrillation appear to have higher rates of atrial arrhythmia recurrence than nonathletes after catheter ablation, with higher rates of atypical flutter. The majority of athletes were able to return to their previous level of activity after ablation.
Exploratory study of seed spots analysis to characterize dose and linear‐energy‐transfer effect in adverse event initialization of pencil‐beam‐scanning proton therapy
Yang, Yunze, Patel, Samir H. , Bridhikitti, Jidapa , Wong, William W. , Halyard, Michele Y. , McGee, L.A. , Rwigema, Jean‐Claude M. , Vora, Sujay A., Liu, Tianming , Fatyga, M., Foote, Robert L. , McGee, Lisa A, Schild, Steven E. , Bues, Martin , Fatyga, Mirek, Liu, Wei

Medical Physics | July 12, 2022 | Volume: 49 | Issue: 9 | Pages: 6237-6252

10.1002/mp.15859 | PMID 35820062 Get It

AbstractBackgroundBoth dose and linear energy transfer (LET) could play a substantial role in adverse event (AE) initialization of cancer patients treated with pencil‐beam‐scanning (PBS) proton therapy. However, not all the voxels within the AE regions are directly induced from the dose and LET effect. It is important to study the synergistic effect of dose and LET in AE initialization by only including a subset of voxels that are dosimetrically important.PurposeTo perform exploratory investigation of the dose and LET effects upon AE initialization in PBS using seed spots analysis.MethodsA total of 113 head‐and‐neck (H&N) cancer patients receiving curative PBS were included. Among them, 20 patients experienced unanticipated CTCAEv4.0 grade ≥3 AEs (AE group) and 93 patients did not (control group). Within the AE group, 13 AE patients were included in the seed spot analysis to derive the descriptive features of AE initialization and the remaining 7 mandible osteoradionecrosis patients and 93 control patients were used to derive the feature‐based volume constraint of mandible osteoradionecrosis. The AE regions were contoured and the corresponding dose–LET volume histograms of AE regions were generated for all patients in the AE group. We selected high LET voxels (the highest 5% of each dose bin) with a range of moderate‐to‐high dose (≥∼40‐Gy relative biological effectiveness) as critical voxels. Critical voxels that were contiguous with each other were grouped into clusters. Each cluster was considered a potential independent seed spot for AE initialization. Seed spots were displayed in a 2D dose–LET plane based on their mean dose and LET to derive the descriptive features of AE initialization. A volume constraint of mandible osteoradionecrosis was then established based on the extracted features using a receiver operating characteristic curve.ResultsThe product of dose and LET (xBD) was found to be a descriptive feature of seed spots leading to AE initialization in this preliminary study. The derived xBD volume constraint for mandible osteoradionecrosis showed good performance with an area under curve of 0.87 (sensitivity of 0.714 and specificity of 0.807 in the leave‐one‐out cross‐validation) for the very limited patient data included in this study.ConclusionOur exploratory study showed that both dose and LET were observed to be important in AE initializations. The derived xBD volume constraint could predict mandible osteoradionecrosis reasonably well in the very limited H&N cancer patient data treated with PBS included in this study.