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Höfer M, Schäfer M, Wang Y, Wink S, Xu S. Genome-wide association study of metabolic traits in the giant duckweed Spirodela polyrhiza. PLANT BIOLOGY (STUTTGART, GERMANY) 2025; 27:18-28. [PMID: 39630110 DOI: 10.1111/plb.13747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Accepted: 10/23/2024] [Indexed: 12/20/2024]
Abstract
The exceptionally high growth rate and high flavonoid content make the giant duckweed Spirodela polyrhiza (L.) Schleid. (Arales: Lemnaceae Martinov) an ideal organism for food production and metabolic engineering. To facilitate this, identification of the genetic basis underlying growth and metabolic traits is essential. Here, we analysed growth and content of 42 metabolites in 137 S. polyrhiza genotypes and characterized the genetics underpinning these traits using a genome-wide association (GWA) approach. We found that biomass positively correlated with the content of many free amino acids, including L-glutamine, L-tryptophan, and L-serine, but negatively correlated with specialized metabolites, such as flavonoids. GWA analysis showed that several candidate genes involved in processes such as photosynthesis, protein degradation, and organ development were jointly associated with multiple metabolic traits. The results suggest the above genes are suitable targets for simultaneous optimization of duckweed growth and metabolite levels. This study provides insights into the metabolic diversity of S. polyrhiza and its underlying genetic architecture, paving the way for industrial applications of this plant via targeted breeding or genetic engineering.
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Li Z, Kang D, Xu S, Xi G, Li L, Zheng L, Guo W, Fu F, Wang C, Ma J, Han X, Xu S, Chen J, Chen J. Collagen signature adds prognostically significant information to staging for breast cancer. ESMO Open 2024; 9:103990. [PMID: 39577107 PMCID: PMC11616558 DOI: 10.1016/j.esmoop.2024.103990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Revised: 10/17/2024] [Accepted: 10/21/2024] [Indexed: 11/24/2024] Open
Abstract
BACKGROUND Tumor-associated collagen signature (TACS) is an independent prognostic factor for breast cancer. However, it is unclear whether the complete collagen signature, including TACS, the TACS-based collagen microscopic features (TCMF1), and the TACS-based nuclear features (TCMF2), can provide additional prognostic information for the current tumor-node-metastasis (TNM) staging system. PATIENTS AND METHODS We included 941 patients with breast cancer from three cohorts: the training (n = 355), internal (n = 334), and external validation cohorts (n = 252). TACS and TCMF1 were obtained by multiphoton microscopy (MPM). TCMF2 was extracted on the hematoxylin and eosin images colocated with MPM images. They were linearly combined to establish a complete collagen signature score for reclassifying current TNM staging into stage Ⅰ (II and Ⅲ)/low risk and stage Ⅰ (II and Ⅲ)/high risk. RESULTS The low-risk collagen signatures 'downstaged' patients in stage II or Ⅲ, while the high-risk collagen signatures 'upstaged' patients with stage Ⅰ tumors. After incorporating the complete collagen signature into the current TNM staging system, the modified staging system had a higher ability to stratify patients [referent, Ⅰ-new; Ⅱ-new, hazard ratio (HR) 8.655, 6.136, and 4.699 in the training, internal validation, and external validation cohorts, respectively; Ⅲ-new, HR 14.855, 11.201, and 13.245 in the corresponding three cohorts, respectively] than the current TNM staging system (referent, Ⅰ; Ⅱ, HR 1.642, 1.853, and 1.371 in the corresponding three cohorts, respectively; Ⅲ, HR 4.131, 4.283, and 3.711 in the corresponding three cohorts, respectively). Furthermore, the modified staging system showed a higher area under the curve than the current TNM staging system (training cohort: 0.843 versus 0.683; internal validation cohort: 0.792 versus 0.661; and external validation cohort: 0.793 versus 0.646). CONCLUSIONS The complete collagen signature is an independent predictor of survival outcomes in breast cancer. It adds significant information about the biological behavior of the disease to staging for breast cancer.
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Zhou BW, Zhang J, Ye XB, Liu GX, Xu X, Wang J, Liu ZH, Zhou L, Liao ZY, Yao HB, Xu S, Shi JJ, Shen X, Yu XH, Hu ZW, Lin HJ, Chen CT, Qiu XG, Dong C, Zhang JX, Yu RC, Yu P, Jin KJ, Meng QB, Long YW. Zhou et al. Reply. PHYSICAL REVIEW LETTERS 2024; 133:169602. [PMID: 39485969 DOI: 10.1103/physrevlett.133.169602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2024] [Accepted: 08/23/2024] [Indexed: 11/03/2024]
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Liu Y, Jiao S, Liu L, Yao S, Xu S. Predicting neuroendocrine neoplasm grade with dual tracer positron emission tomography/computed tomography (PET/CT) using 18F-fluorodeoxyglucose ( 18F-FDG) and 18F-AlF-NOTA-octreotide: a lesion-based analysis. Clin Radiol 2024; 80:106715. [PMID: 39504887 DOI: 10.1016/j.crad.2024.09.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 09/17/2024] [Accepted: 09/22/2024] [Indexed: 11/08/2024]
Abstract
AIM The aim of this study was to investigate the ability of dual tracer positron emission tomography/computed tomography (PET/CT) using 18F-fluorodeoxyglucose (18F-FDG) and 18F-AlF-NOTA-octreotide (18F-OC) in predicting neuroendocrine neoplasm (NEN) grade. The lesions that have been histologically confirmed were accurately located using both 18F-FDG and 18F-OC PET/CT. MATERIALS AND METHODS For each lesion, the standardized uptake value (SUV)max was measured, and tumor-to-background ratio was calculated by dividing the SUVmax by the SUVmean of background tissue at the two scans. SUVR was calculated by dividing the SUVmax of the lesion at 18F-OC PET/CT by the SUVmax at 18F-FDG PET/CT. For evaluating the correlation between continuous variables and lesion grade, the Spearman rank correlation test was used. Receiver operating characteristic (ROC) curve was used to evaluate the performance of PET/CT parameter in discriminating lesions of different grades. RESULTS A total of 49 patients (22 males, 27 females; mean age: 56.5 ± 14.3 years; range: 14-85 years) and 65 lesions were included in this study. A substantial correlation was observed between SUVR and lesion grade (rho = -0.655, p < 0.001), better than other PET/CT parameters. For discriminating G1/2 neuroendocrine tumor (NET) from G3 NET and neuroendocrine carcinoma (NEC), SUVR had the largest area under ROC curve (AUC) of 0.88. With the cut-off value of 2.217, we got the best Youden's index, 0.668. For discriminating G1/2/3 NET from NEC, SUVR and OC SUVmax had the largest AUC of 0.923. With the cut-off value of OC SUVmax of 4.35, we got the best Youden's index, 0.805. CONCLUSION This study suggests that 18F-FDG and 18F-OC PET/CT are complementary in evaluating the grade of NEN and that SUVR is a promising tool for predicting NEN grade.
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Hanel W, Marchenko N, Xu S, Yu SX, Weng W, Moll U. Correction to: Two hot spot mutant p53 mouse models display differential gain of function in tumorigenesis. Cell Death Differ 2024; 31:1394. [PMID: 39256520 PMCID: PMC11445441 DOI: 10.1038/s41418-024-01366-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2024] Open
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Xu S, Luo J, Tang W, Bao H, Wang J, Chang S, Zou Z, Fan X, Liu Y, Jiang C, Wu X. Detecting pulmonary malignancy against benign nodules using noninvasive cell-free DNA fragmentomics assay. ESMO Open 2024; 9:103595. [PMID: 39088983 PMCID: PMC11345357 DOI: 10.1016/j.esmoop.2024.103595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 05/02/2024] [Accepted: 05/14/2024] [Indexed: 08/03/2024] Open
Abstract
BACKGROUND Early screening using low-dose computed tomography (LDCT) can reduce mortality caused by non-small-cell lung cancer. However, ∼25% of the 'suspicious' pulmonary nodules identified by LDCT are later confirmed benign through resection surgery, adding to patients' discomfort and the burden on the healthcare system. In this study, we aim to develop a noninvasive liquid biopsy assay for distinguishing pulmonary malignancy from benign yet 'suspicious' lung nodules using cell-free DNA (cfDNA) fragmentomics profiling. METHODS An independent training cohort consisting of 193 patients with malignant nodules and 44 patients with benign nodules was used to construct a machine learning model. Base models using four different fragmentomics profiles were optimized using an automated machine learning approach before being stacked into the final predictive model. An independent validation cohort, including 96 malignant nodules and 22 benign nodules, and an external test cohort, including 58 malignant nodules and 41 benign nodules, were used to assess the performance of the stacked ensemble model. RESULTS Our machine learning models demonstrated excellent performance in detecting patients with malignant nodules. The area under the curves reached 0.857 and 0.860 in the independent validation cohort and the external test cohort, respectively. The validation cohort achieved an excellent specificity (68.2%) at the targeted 90% sensitivity (89.6%). An equivalently good performance was observed while applying the cut-off to the external cohort, which reached a specificity of 63.4% at 89.7% sensitivity. A subgroup analysis for the independent validation cohort showed that the sensitivities for detecting various subgroups of nodule size (<1 cm: 91.7%; 1-3 cm: 88.1%; >3 cm: 100%; unknown: 100%) and smoking history (yes: 88.2%; no: 89.9%) all remained high among the lung cancer group. CONCLUSIONS Our cfDNA fragmentomics assay can provide a noninvasive approach to distinguishing malignant nodules from radiographically suspicious but pathologically benign ones, amending LDCT false positives.
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Xu S, Qu LJ, Chen X, Zhu XL, Niu FN. [Clinical, imaging, and pathological characteristics of 35 cases of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome]. ZHONGHUA NEI KE ZA ZHI 2024; 63:674-679. [PMID: 38951091 DOI: 10.3760/cma.j.cn112138-20231227-00411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
Objective: To summarize the clinical, imaging, and pathological characteristics of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome (MELAS) to improve the diagnosis of this rare disease. Methods: A retrospective case series was conducted to collect the clinical data and results of genetic testing, muscle biopsy, and imaging studies including computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS) of 35 patients with MELAS admitted to the Nanjing Drum Tower Hospital from 2012 to 2021. Descriptive statistical analysis including mean, standard deviation, and frequency percentage were carried out. Results: The average age of onset of the patients was 30.2±2.3 years; the prevalence of family history was 20%. The two main initial symptoms were limb weakness and convulsions. The clinical manifestations of the neuromuscular system were proximal muscle weakness and exercise intolerance. The endocrine system is the most affected outside the neuromuscular system, with diabetes being the most common condition. Among the five patients who underwent brain CT, four showed hypodense lesions and two had calcified lesions. Brain MRI in 26 patients showed that the lesions more often affected the parietal lobe, basal ganglia, temporal lobe, occipital lobe, and frontal lobe than the infratentorial areas. Twelve of these individuals exhibited different levels of brain atrophy. Among the 10 patients who underwent 1H-MRS, nine showed a decrease in N-acetylaspartate (NAA) levels, eight exhibited abnormal lactate elevation (Lac peaks), whereas six had both reduced NAA levels and the presence of Lac peaks. Thirty-one patients underwent genetic testing; among them, 25 were found to have the mt.3243A>G mutation, while the remaining six exhibited rare gene alterations. Muscle biopsies were performed in 21 patients, and 15 showed abnormal mitochondrial proliferation manifested by ragged red fibers and defective oxidative phosphorylation manifested by cytochrome C oxidase (COX) enzyme-deficient muscle fibers. Conclusion: The clinical manifestations of MELAS syndrome are variable and complex, and early atypical symptoms could be missed or misdiagnosed. A detailed clinical history, imaging MRS analysis, muscle biopsy, and genetic testing are necessary to confirm the accurate diagnosis of MELAS.
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Xie Y, Fang X, Wang A, Xu S, Li Y, Xia W. Association of cord plasma metabolites with birth weight: results from metabolomic and lipidomic studies of discovery and validation cohorts. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2024; 64:87-96. [PMID: 38243991 DOI: 10.1002/uog.27591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 11/29/2023] [Accepted: 01/15/2024] [Indexed: 01/22/2024]
Abstract
OBJECTIVE Birth weight is a good predictor of fetal intrauterine growth and long-term health, and several studies have evaluated the relationship between metabolites and birth weight. The aim of this study was to investigate the association of cord blood metabolomics and lipidomics with birth weight, using a two-stage discovery and validation approach. METHODS Firstly, a pseudotargeted metabolomics approach was applied to detect metabolites in 504 cord blood samples in the discovery set enrolled from the Wuhan Healthy Baby Cohort, China. Metabolome-wide association scan analysis and pathway enrichment were applied to identify metabolites and metabolic pathways that were significantly associated with birth weight adjusted for gestational age Z-score (BW Z-score). Logistic regression models were used to analyze the association of metabolites in the most significantly associated pathways with small-for-gestational age (SGA) at delivery and low birth weight (LBW). Subsequently, 350 cord blood samples in a validation cohort were subjected to targeted analysis to validate the metabolites identified by screening in the discovery cohort. RESULTS In the discovery set, of 2566 metabolites detected, 2418 metabolites were retained for subsequent analysis after data preprocessing. Of these, 513 metabolites were significantly associated with BW Z-score (P-value adjusted for false discovery rate (PFDR) < 0.05), of which 298 Kyoto Encyclopedia of Genes and Genomes (KEGG)-annotated metabolites were included in the pathway analysis. The primary bile acid biosynthesis pathway was the most relevant metabolic pathway associated with BW Z-score. Elevated cord plasma primary bile acids were associated with lower BW Z-score and higher risk of SGA or LBW in the discovery and validation cohorts. In the validation set, a 2-fold increase in taurochenodeoxycholic acid (TCDCA) and in taurocholic acid (TCA) was associated with a decrease in BW Z-score (estimated β coefficient, -0.10 (95% CI, -0.20 to 0.00) and -0.18 (95% CI, -0.31 to -0.04), respectively), after adjusting for covariates. In addition, a 2-fold increase in cord plasma TCDCA and of cord plasma TCA was associated with an increased risk of SGA (adjusted odds ratio (OR), 1.52 (95% CI, 1.00-2.30) and 1.77 (95% CI, 1.05-2.98), respectively). The adjusted OR for LBW, for a 2-fold increase in TCDCA and TCA concentration, were 2.39 (95% CI, 1.00-5.71) and 3.21 (95% CI, 0.96-10.74), respectively. CONCLUSIONS These results indicate a significant association of elevated primary bile acids, particularly TCDCA and TCA, in cord blood with lower BW Z-score, as well as increased risk of SGA and LBW. Abnormalities of primary bile acid metabolism may play an important role in restricted fetal development. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.
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Liu J, Fang X, Cao S, Shi Y, Li S, Liu H, Li Y, Xu S, Xia W. Associations of ambient temperature and total cloud cover during pregnancy with newborn vitamin D status. Public Health 2024; 231:179-186. [PMID: 38703492 DOI: 10.1016/j.puhe.2024.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 02/24/2024] [Accepted: 03/27/2024] [Indexed: 05/06/2024]
Abstract
OBJECTIVES We aimed to estimate the effects of temperature and total cloud cover before birth on newborn vitamin D status. STUDY DESIGN Prospective birth cohort. METHODS This study included 2055 mother-newborn pairs in Wuhan, Hubei province, China. The data of temperature and total cloud cover from 30 days before birth were collected, and cord blood 25-hydroxyvitamin D [25(OH)D] were determined. Restricted cubic spline regression models, multiple linear regression models, and logistic regression models were applied to estimate the associations. RESULTS A "J" shaped curve was observed between temperature and vitamin D status, and an inverse "J" shaped curve was observed between total cloud cover and vitamin D status. Compared to the fourth quartile (75-100th percentile, Q4) of average temperature (30 days before birth), the odds ratio (OR) for Q1 (0-25th percentile) associated with the vitamin D deficiency occurrence (<20 ng/mL) was 3.63 (95% CI, 1.54, 8.65). Compared to Q1 of the average total cloud cover (30 days before birth), the OR associated with the occurrence of vitamin D deficiency was 2.38 (95% CI, 1.63, 3.50) for the Q4. CONCLUSIONS Low temperature and high cloud cover before delivery were significantly associated with an increased probability of vitamin D deficiency in newborns. The findings suggested that pregnancy women lacking sufficient sunlight exposure still need vitamin D supplement to overcome the potential vitamin D deficiency status.
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Xu S, Tang J. [Biological threats to global malaria elimination II Deletion in the malaria rapid diagnostic test target Plasmodium falciparum histidine-rich protein 2/3 genes]. ZHONGGUO XUE XI CHONG BING FANG ZHI ZA ZHI = CHINESE JOURNAL OF SCHISTOSOMIASIS CONTROL 2024; 36:239-242. [PMID: 38952308 DOI: 10.16250/j.32.1374.2024089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
The global malaria epidemic is still severe. Because of simple procedures, rapid detection and accuracy results, rapid diagnostic test (RDT) has become the most important and the most widely used diagnostic tool for malaria prevention and control. However, deletions in the RDT target Plasmodium falciparum histidine-rich protein 2/3 (Pfhrp2/3) genes may cause false-negative results of RDT, which has been included as one of the four biological threats to global malaria elimination. This article reviews the applications of RDT in the global malaria diagnosis, analyzes the threats and challenges caused by Pfhrp2/3 gene deletion, proposes methods for monitoring Pfhrp2/3 gene deletion, and summarizes the causes and countermeasures of negative RDT detections, so as to provide insights into consolidation of malaria elimination achievements in China and contributions to global malaria elimination.
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Zheng H, Xu S, Chen SM. [Research progress on the role of memory B cells in type 2 inflammatory diseases]. ZHONGHUA ER BI YAN HOU TOU JING WAI KE ZA ZHI = CHINESE JOURNAL OF OTORHINOLARYNGOLOGY HEAD AND NECK SURGERY 2024; 59:505-509. [PMID: 38811185 DOI: 10.3760/cma.j.cn115330-20231218-00310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
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Gao Y, Hu Y, Xu S, Liang H, Lin H, Yin TH, Zhao K. Characterisation of the mitochondrial genome and phylogenetic analysis of Toxocara apodemi (Nematoda: Ascarididae). J Helminthol 2024; 98:e33. [PMID: 38618902 DOI: 10.1017/s0022149x24000221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
We first sequenced and characterised the complete mitochondrial genome of Toxocara apodeme, then studied the evolutionary relationship of the species within Toxocaridae. The complete mitochondrial genome was amplified using PCR with 14 specific primers. The mitogenome length was 14303 bp in size, including 12 PCGs (encoding 3,423 amino acids), 22 tRNAs, 2 rRNAs, and 2 NCRs, with 68.38% A+T contents. The mt genomes of T. apodemi had relatively compact structures with 11 intergenic spacers and 5 overlaps. Comparative analyses of the nucleotide sequences of complete mt genomes showed that T. apodemi had higher identities with T. canis than other congeners. A sliding window analysis of 12 PCGs among 5 Toxocara species indicated that nad4 had the highest sequence divergence, and cox1 was the least variable gene. Relative synonymous codon usage showed that UUG, ACU, CCU, CGU, and UCU most frequently occurred in the complete genomes of T. apodemi. The Ka/Ks ratio showed that all Toxocara mt genes were subject to purification selection. The largest genetic distance between T. apodemi and the other 4 congeneric species was found in nad2, and the smallest was found in cox2. Phylogenetic analyses based on the concatenated amino acid sequences of 12 PCGs demonstrated that T. apodemi formed a distinct branch and was always a sister taxon to other congeneric species. The present study determined the complete mt genome sequences of T. apodemi, which provide novel genetic markers for further studies of the taxonomy, population genetics, and systematics of the Toxocaridae nematodes.
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Ge RL, Liang Y, Xu S. [The influencing factors on the spinal sagittal alignment and global balance status of degenerative thoracolumbar kyphosis]. ZHONGHUA YI XUE ZA ZHI 2024; 104:1036-1042. [PMID: 38561298 DOI: 10.3760/cma.j.cn112137-20231027-00913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Objective: To explore the effect of degenerative thoracolumbar kyphosis (DTLK) on the sagittal alignment of the spine, as well as the impact on spinal parameters and imbalance secondary to thoracolumbar kyphosis. Methods: A case-control study. A total of 128 DTLK patients who aged over 50 years [thoracolumbar kyphosis (TLK)>15°] treated in Peking University People's Hospital from January 2018 to December 2021 (DTLK group) were retrospectively included in this study. Other 73 contemporaneous patients with lumbar spinal stenosis or disc herniation without thoracolumbar kyphosis (TLK=0°±15°) were enrolled into the control group. The following parameters were obtained on spine X-ray: TLK, thoracic kyphosis (TK), lumbar lordosis (LL) and sagittal vertical axis (SVA). In addition, the osteoporosis (OP) was evaluated by dual-emission X-ray absorptiometry (DXA), and the L5/S1 disc signal grading (Pfirrmann grading) was evaluated on MRI. Based on the age, the Lafage formula SVA=2× (age-55)+25 was used to distinguish balance/imbalance, and the DTLK patients were divided into balanced and an imbalanced group, the characteristics and influencing factors of the loss of sagittal balance in this population were clarified, and the interaction among various parts of the spine under a state of balance was analyzed too. Results: The TK (30.0°±13.5° vs 24.2°±7.4°) and TLK (26.6°±9.7° vs 6.0°±6.6°) in the DTLK group were both larger than those in control group while LL was smaller (34.4°±17.7° vs 44.2°±10.3°) (all P<0.001). TK was correlated to TLK (r=0.234, P=0.008) and LL (r=0.539, P<0.001) in DTLK group. LL loss was positively correlated to L5/S1 disc signal reduction (r=0.253, P=0.044). LL loss [RR=1.04(1.01-1.08)] and OP [RR=3.97(1.09, 14.50)] were influencing factors for the occurrence of imbalance in DTLK patients. The influencing factors for TK in DTLK balance group were LL (β=0.572, P<0.001) and age (β=0.351, P=0.045). The positive influencing factor for TK in imbalanced group is LL (β=0.209, P=0.015), and the impact is weaker than balanced group. Conclusions: Loss of LL and osteoporosis are more likely to cause imbalance and kyphosis in DTLK patients. In DTLK balance group, the proximal spine is regulated by lumbar spine, and the synergistic effect between the two parts maintains balance.
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Gao Y, Cao T, Lin KZ, Guo DL, Zhang SF, Zhu XL, Zhang RT, Yan SC, Xu S, Zhao DM, Ma X. A high resolution reaction microscope with universal two-region time-focusing method. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:043302. [PMID: 38578918 DOI: 10.1063/5.0202775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 03/19/2024] [Indexed: 04/07/2024]
Abstract
This paper presents a novel reaction microscope designed for ion-atom collision investigations, established at the Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China. Its time-of-flight (TOF) spectrometer employs an innovative flight-time focusing method consisting of two acceleration regions, providing optimal time focusing conditions for charged fragments with diverse initial velocities. The TOF spectrometer's axis intentionally tilts by 12° relative to the ion beam direction, preventing potential obstructions from the TOF grid electrodes. The introduced focusing method allows for a flexible time-focusing TOF spectrometer design without restricting the length ratio of the two regions. In addition, this configuration in our case significantly suppresses noise on the recoil ion detector produced by residual gas in the ion beam trajectory, which is a considerable challenge in longitudinal spectrometers. In a test experiment on the single electron capture reaction involving 62.5 keV/u He2+ ions and a helium atomic beam, the recoil longitudinal momentum resolution achieved 0.068 atomic units. This novel configuration and successful test run show excellent precision for ion-atom collision studies.
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Lee C, Xu S, Samad T, Goodyer WR, Raissadati A, Heinrich P, Wu SM. The cardiac conduction system: History, development, and disease. Curr Top Dev Biol 2024; 156:157-200. [PMID: 38556422 DOI: 10.1016/bs.ctdb.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
The heart is the first organ to form during embryonic development, establishing the circulatory infrastructure necessary to sustain life and enable downstream organogenesis. Critical to the heart's function is its ability to initiate and propagate electrical impulses that allow for the coordinated contraction and relaxation of its chambers, and thus, the movement of blood and nutrients. Several specialized structures within the heart, collectively known as the cardiac conduction system (CCS), are responsible for this phenomenon. In this review, we discuss the discovery and scientific history of the mammalian cardiac conduction system as well as the key genes and transcription factors implicated in the formation of its major structures. We also describe known human diseases related to CCS development and explore existing challenges in the clinical context.
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Wang G, Tang H, Xu S, Zhu H, Peng Y, Wang C. Gastrointestinal: Primary pancreatic epithelioid angiomyolipoma. J Gastroenterol Hepatol 2024; 39:416. [PMID: 37940773 DOI: 10.1111/jgh.16390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/10/2023] [Indexed: 11/10/2023]
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Xu S, Li L, Shen L, Wang X, Feng W, Liu S. Unexpected partial RNA deletion by two different novel COL6A2 mutations leads to Ullrich congenital muscular dystrophy. QJM 2024; 117:61-62. [PMID: 37738610 DOI: 10.1093/qjmed/hcad209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Indexed: 09/24/2023] Open
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Ivanovic M, Chan A, Cheng E, Xu S, Lee C, You J, Franquiz M, Fazal M, Batchelder R, Wu SM, Reddy SA, Katsumoto T, Ramchandran K, Colevas AD, Khan SA, Fan AC, Cheng P, Wakelee H, Witteles R, Neal JW, Waliany S, Zhu H. THE IMPACT OF ROUTINE CARDIAC TROPONIN I-BASED CARDIOTOXICITY SCREENING ON CLINICAL OUTCOMES IN PATIENTS ON CANCER IMMUNOTHERAPY. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.22.24301442. [PMID: 38343840 PMCID: PMC10854294 DOI: 10.1101/2024.01.22.24301442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Purpose Immune checkpoint inhibitors (ICI) used as cancer therapy have been associated with a range of cardiac immune-related adverse events (irAEs), including fulminant myocarditis with a high case fatality rate. Early detection through cardiotoxicity screening by biomarker monitoring can lead to prompt intervention and improved patient outcomes. In this study, we investigate the association between cardiotoxicity screening with routine serial troponin I monitoring in asymptomatic patients receiving ICI, cardiovascular adverse event (CV AE) detection, and overall survival (OS). Methods We instituted a standardized troponin I screening protocol at baseline and with each ICI dose (every 2-4 weeks) in all patients receiving ICI at our center starting Jan 2019. We subsequently collected data in 825 patients receiving ICI at our institution from January 2018 to October 2021. Of these patients, 428 underwent cardiotoxicity screening with serial troponin I monitoring during ICI administration (Jan 2019-Oct 2021) and 397 patients were unmonitored (Jan 2018-Dec 2018). We followed patients for nine months following their first dose of ICI and compared outcomes of CV AEs and OS between monitored and unmonitored patients. Additionally, we investigated rates of CV AEs, all-cause mortality, and oncologic time-to-treatment failure (TTF) between patients with an elevated troponin I value during the monitoring period versus patients without elevated troponin I. Results We found a lower rate of severe (grades 4-5) CV AEs, resulting in critical illness or death, in patients who underwent troponin monitoring (0.5%) compared to patients who did not undergo monitoring (1.8%), (HR 0.17, 95% CI 0.02-0.79, p = 0.04). There was no difference in overall CV AEs (grades 3-5) or OS between monitored and unmonitored patients. In the entire cohort, patients with at least one elevated troponin I during the follow up period, during routine monitoring or unmonitored, had a higher risk of overall CV AEs (HR 10.96, 95% CI 4.65-25.85, p<0.001) as well as overall mortality (HR 2.67, 95% CI 1.69 - 4.10, p<0.001) compared to those without elevated troponin. Oncologic time-to-treatment failure (TTF) was not significantly different in a sub-cohort of monitored vs. unmonitored patients. Conclusions Patients undergoing cardiotoxicity screening with troponin I monitoring during ICI therapy had a lower rate of severe (grade 4-5) CV AEs compared patients who were not screened. Troponin I elevation in screened and unscreened patients was significantly associated with increased CV AEs as well as increased mortality. Troponin I monitoring did not impact oncologic time-to-treatment-failure in a sub-cohort analysis of patients treated with ICI. These results provide preliminary evidence for clinical utility of cardiotoxicity screening with troponin I monitoring in patients receiving ICI therapy.
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Yan S, Zhang RT, Xu S, Zhang SF, Ma X. Molecular Ionization Dissociation Induced by Interatomic Coulombic Decay in an ArCH_{4}-Electron Collision System. PHYSICAL REVIEW LETTERS 2023; 131:253001. [PMID: 38181359 DOI: 10.1103/physrevlett.131.253001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/11/2023] [Accepted: 11/15/2023] [Indexed: 01/07/2024]
Abstract
Interatomic Coulombic decay (ICD) is a significant fragmentation mechanism observed in weakly bound systems. It has been widely accepted that ICD-induced molecular fragmentation occurs through a two-step process, involving ICD as the first step and dissociative-electron attachment (DEA) as the second step. In this study, we conducted a fragmentation experiment of ArCH_{4} by electron impact, utilizing the coincident detection of one electron and two ions. In addition to the well-known decay pathway that induces pure ionization of CH_{4}, we observed a new channel where ICD triggers the ionization dissociation of CH_{4}, resulting in the cleavage of the C-H bond and the formation of the CH_{3}^{+} and H ion pair. The high efficiency of this channel, as indicated by the relative yield of the Ar^{+}/CH_{3}^{+} ion pair, agrees with the theoretical prediction [L. S. Cederbaum, J. Phys. Chem. Lett. 11, 8964 (2020).JPCLCD1948-718510.1021/acs.jpclett.0c02259; Y. C. Chiang et al., Phys. Rev. A 100, 052701 (2019).PLRAAN2469-992610.1103/PhysRevA.100.052701]. These results suggest that ICD can directly break covalent bonds with high efficiency, bypassing the need for DEA. This finding introduces a novel approach to enhance the fragmentation efficiency of molecules containing covalent bonds, such as DNA backbone.
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Bal G, Xu S, Shi L, Voronenko Y, Narayanan M, Shao L, Kuduvalli G, Han B, Kovalchuk N, Surucu M. Evaluation of Treatment Interruptions and Recovery during Biology-Guided Radiotherapy Delivery. Int J Radiat Oncol Biol Phys 2023; 117:e722-e723. [PMID: 37786107 DOI: 10.1016/j.ijrobp.2023.06.2233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) A Biology-guided Radiotherapy (BgRT) based device is designed to use Positron Emission Tomography (PET) signals to achieve tracked dose delivery. The goal of this study is to investigate the dose delivery accuracy in case of interruption during BgRT treatment, and resumption in a separate treatment session for a multi-target delivery, as the PET activity continues to decay. MATERIALS/METHODS A custom-built large anthropomorphic phantom (LAP) including a 26 mm spherical target with 3D independent motion and two 22 mm spherical targets with 1D sinusoidal motion embedded in water was used. All three targets were filled with FGD in an 8:1 target to background uptake ratio (41.52 kBq/ml in target and 5.19 kBq/ml in background). During BgRT delivery, the treatment was intentionally paused during delivery to the second target and the current treatment session was ended to generate a partial fraction. Then the partial fraction was continued in a new session, where the CT scan localization and PET pre-scan were repeated using the existing PET activity present in the phantom. The newly acquired PET pre-scan, was then used to determine if sufficient PET counts were present to resume treatment delivery. The interruption and recovery algorithm is designed to calculate the fluence that needs to be delivered to the remaining targets as well as the residual fluence to be given to the targets that have already received partial dose prior to the interruption. Once the new fluence is recomputed, the treatment is resumed. The delivered doses were captured using radiochromic film (EBT-XD) inserted in the target as well as post-treatment dose calculations based on the delivered beamlet sequence to evaluate the results in terms of dosimetric coverage and margin loss. The margin loss is calculated as the maximum difference between the distance from the Clinical Target Volume (CTV) contour to the 97% isodose contour in the treatment plan and the on the film. The dosimetric coverage is defined as the percentage of voxels within the CTV that lies within 97% and 130% of the prescribed dose. RESULTS As shown in the table below, a margin loss of less than 3 mm for all targets and 100% CTV coverage was achieved. After treatment interruptions, the PET safety evaluation based on the PET pre-scan helped to determine whether the treatment could be continued on the same day using the same injected PET activity (an NTS value ≧ 2 and AC value ≧ 5 kBq/ml). CONCLUSION This study demonstrated that the BgRT system is able to deliver the prescribed dose to all targets with independent motion, even when an interruption and resumption occurs during treatment. In case such an interruption if the remaining PET activity satisfies the BgRT safety evaluation, the treatment can continue to deliver the remainder of the BgRT doses.
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Bal G, Kovalchuk N, Schmall J, Voronenko Y, Bailey T, Xu S, Shi L, Groll A, Sharma S, Ramos K, Shao L, Narayanan M, Kuduvalli G, Han B, Surucu M. Intrafraction Dosimetric Evaluation of Biology-Guided Radiotherapy to a Target Under Respiratory Motion. Int J Radiat Oncol Biol Phys 2023; 117:e680-e681. [PMID: 37786004 DOI: 10.1016/j.ijrobp.2023.06.2141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) To evaluate the reproducibility and variability of biology-guided radiotherapy (BgRT) treatments using a large anthropomorphic phantom modeling the motion amplitude of a lung tumor. MATERIALS/METHODS RefleXion X1 is equipped with two opposing 90 degrees PET detector arcs to capture the radionuclide emissions and direct the 6MV Linac to treat the lesions in real time. A custom-built phantom filled with a liquid [¹⁸F]Fluorodeoxyglucose (FDG) solution was used. Fillable target and OAR structures were 3D printed and attached to motion stages. The GTV = CTV was matched to the spherical 22 mm diameter target, and the PTV was a 5 mm expansion from the CTV volume. The Biology Tracking Zone (BTZ) was generated after adding 5 mm margin to the motion extent of the CTV. The OAR was a large C-shape annulus (emulating a heart) that was approximately 3 cm from the target. The 3D independent motion trajectory of the target was designed to mimic lung motion: range of +5.8 mm to -4.9 mm in LR, range of +14.4 mm to -11.3 mm in SI, and range of +5.2 mm to -5.1 mm in AP directions. The OAR motion waveform used a 1D sinusoidal pattern with a 5 mm amplitude in SI direction. The target and the OAR were filled with 40 kBq/mL while the background had 5 kBq/mL FDG. A BgRT Modeling (imaging-only) PET acquisition was performed using RefleXion X1 and used to generate a 4-fraction BgRT treatment plan prescribing 10 Gy/fraction to PTV. For each delivery, target, OAR and background were filled with the same FDG concentrations as in the BgRT Modeling PET planning scan. Dosimetry to the target and OAR were both measured using an ion-chamber (Exradin A14SL) and film in the coronal plane through the center of the GTV for all 4 fractions. RESULTS The mean activity concentration within the (BTZ) was 7.4 ± 0.8 kBq/mL. The calculated signal-to-noise ratio metric (Normalized Target Signal) within the BTZ was 4.0 ± 0.3. Total treatment times were all less than 35 minutes (34.3 ± 0.2). Prescription dose coverage to the CTV for all 4 fractions was 100%. Ion chamber measurements in the CTV were -1.6 ± 1.3% relative to the planned dose over the active area of the ion-chamber. Minimum and maximum doses to the CTV, measured on film, were -7.7 ± 2.2% and 1.3 ± 1.4%, calculated relative to the planned dose distribution, respectively. The OAR maximum point dose measured on film was -8.7 ± 2.9%, calculated relative to the maximum OAR dose predicted on the bounded dose-volume histogram. CONCLUSION Based on this initial study, accurate and reproducible dosimetry can be achieved for targets under respiratory motion using biology-guided radiotherapy over the course of a complete course of treatment. Further studies are needed to evaluate the intrafraction dosimetry of BgRT delivery under various motion models and tumor sizes.
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Schmall J, Bal G, Khan S, Xu S, Voronenko Y, Shi L, Mitra A, Groll A, Sharma S, Ramos K, Shao L, Narayanan M, Olcott P, Kuduvalli G, Han B, Kovalchuk N, Surucu M. Dosimetric Accuracy of Multi-Target Biology-Guided Radiotherapy Treatments in a Single Session. Int J Radiat Oncol Biol Phys 2023; 117:e722. [PMID: 37786108 DOI: 10.1016/j.ijrobp.2023.06.2232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) We present the first dosimetric measurements of single session, multi-target BgRT deliveries using a clinically realistic motion phantom on a research-only version of the RefleXion X1 system. MATERIALS/METHODS A custom-made anthropomorphic phantom of a human torso with embedded fillable targets mimicking 18F-FDG-avid lesions was used. From the three embedded spherical targets, Target 1 was 26 mm in diameter coupled with a 3D independent respiratory motion with 22 mm range, whereas Target 2 and 3 were 22 mm in diameter and moved with a 1D 5 mm maximum sinusoidal motion. The 18F-FDG concentration in the background cavity of the phantom was 5 kBq/ml, and the targets were loaded with 10:1, 8:1 and 6:1 contrast relative to the background for Targets 1, 2, 3, respectively. Spherical structures were contoured as GTVs (CTV = GTV) and a 5 mm margin was added to create PTVs. Motion extent of the tumors were captured to create biological tracking zones for each target. Treatment plans were generated using a research version of the Reflexion treatment planning software to deliver 8 Gy/fx to the PTVs. The treatment delivery was repeated 2 times, and each time the phantom was refilled according to the plan. PET image evaluation metrics for each of the three targets were also recorded. Target dosimetry was measured using a combination of radiographic film and ion chamber. The maximum distance between the 97% prescription isodose line from the plan and the film measurements was used to characterize the dosimetric accuracy of the tracked deliveries. CTV and PTV min, max, and mean doses measured on film were also recorded for each target. RESULTS Treatment plans were successfully created with 100% prescription dose coverage to each target loaded with different FDG ratios. Total treatment times for the single-plan, three-target deliveries were less than 80 minutes. PET evaluation metrics at imaging-only and pre-scan, and planning and film dosimetry to the GTV and PTV for each of the three targets is shown in table below (mean ± standard deviation of both deliveries). The CTV dose coverage was maintained for all targets. The shrinkage distance of the 97% prescription dose isodose line on the film plane for all three targets was less than 3 mm for both tests, and ranged from -0.4 to -2.34 mm. CONCLUSION These results demonstrate that high tracking accuracy and dosimetric accuracy can be achieved in single session, multi-target deliveries over a range of target-to-background 18F-FDG concentrations and target motion patterns.
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Mitra A, Bal G, Xu S, Voronenko Y, Schmall J, Narayanan M, Shao L, Kuduvalli G. Treatment Plan Creation and Delivery with and without BgRT for Static and Motion Trajectories. Int J Radiat Oncol Biol Phys 2023; 117:e697-e698. [PMID: 37786043 DOI: 10.1016/j.ijrobp.2023.06.2179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) In this work we try to validate the motion tracking capabilities of BgRT for periodic and step motion trajectories. SBRT plans that matches the corresponding BgRT plans are created and delivered to the same phantom with and without motion and results are evaluated. Using BgRT based SBRT plans eliminates any user bias and creates SBRT plans that would represent treatment delivery scenarios that could have happened if the PET guided BgRT was not present for that treatment. MATERIALS/METHODS To validate SBRT plans that matches the BgRT plans, we used three different types of motion patterns (1) static, (2) lung tumor motion and (3) one-centimeter step-shift. The lung tumor motion (∼25 mm in IEC-Y, ∼7 mm in IEC-X and ∼ 10 mm in IEC-Z) was used as it represents a continuous motion of the target for the entire length of the study while the step-shift case corresponds to the patient or tumor shifting between the localization CT and the start of treatment. First, a 10 Gy per fraction BgRT plan was created for each of the three experiments based on the corresponding PET image. Then, the BgRT plans were delivered to the corresponding targets with and without motion and results are evaluated. To perform a comparative study that assess the performance of BgRT and traditional SBRT (planning and delivery methods), the exact same plan fluence of BgRT plan for each experiment was used to create the corresponding SBRT plans. The newly created SBRT plans were delivered to the corresponding phantom experiments and were compared against BgRT delivery in terms of dose coverage and target margin loss using radiochromic film that moves with the target. The margin loss was calculated as the difference between the distance from the CTV contour to the 97% isodose contour in the treatment plan and the CTV contour to the 97% isodose contour on the film. Dosimetric coverage was on the other hand calculated as the percentage of the voxels within the CTV that lies within 97% and 130% of the prescribed dose. RESULTS The results showed that the margin loss for BgRT is less than 3 mm, while for the SBRT plans were more than 3 mm when target motion is present. The dosimetric coverage for BgRT was 100% for all three cases, however less than 100% for the SBRT cases with motion. Table showing margin loss for the various experiments for a prescription dose of 10 Gy. CONCLUSION The results shows that BgRT is capable of tracking the tumor motion and delivering the prescribed dose to the moving target.
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Liu Y, Chen Z, Zhou Q, Shang X, Zhao W, Zhang G, Xu S. A Feasibility Study of Dose Band Prediction in Radiotherapy: Predicting a Dose Spectrum. Int J Radiat Oncol Biol Phys 2023; 117:e691. [PMID: 37786031 DOI: 10.1016/j.ijrobp.2023.06.2164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Current deep learning-based dose prediction methods can only predict a specific dose distribution. If the predicted dose is inaccurate, no more options can be selected. We proposed a novel dose prediction method named dose band prediction, which outcomes a spectrum of predicted dose distribution for planning and quality assurance (QA). MATERIALS/METHODS Upper-Band and Lower-Band losses were involved in 3D convolution neural networks to establish the Upper-Band Network (UBN) and Lower-Band Network (LBN). Each voxel's ideal dose spectrum (dose band) was defined by the maximum/minimum rational dose predicted by UBN/LBN. 130 NPC cases with Tomotherapy (dataset 1), 49 cervix cases with IMRT (dataset 2) and 43 cervix cases with VMAT (dataset 3) were enrolled to establish and evaluate our dose band prediction method. RESULTS The dose band prediction method can successfully predict a spectrum of doses. Upper-Band/Lower-Band presents maximum/minimum rational dose; Middle-Line presents the average of Upper-Band and Lower-Band. The clinical implement dose was used as the reference dose. We evaluated the maximum interval between the reference and Upper-Band/Middle-Line/Lower-Band doses, and the percentage dose difference was used as the evaluation method. The differences in PTV for Upper-Band, Middle-Line and Lower-Band in dataset 1 were within 2.47%, 0.54%, and 2.8%; in dataset 2, they were within 0.37%, 1.15%, and 2.69%; in dataset 3, they were within 0.96%, 0.35%, and 1.66%. The mean difference of OARs for the Upper-Band, Middle-Line and Lower-Band in dataset 1 were within 8.13%, 4.97%, and 8.19%; in dataset 2, they were within 8.8%, 4.48%, and 5.52%; in dataset 3, they were within 4.01%, 3.13%, and 5.79% (shown in Table 1). CONCLUSION Dose Band prediction achieved high-accuracy dose prediction by the Middle-Line. More importantly, the Upper-Band/Lower-Band provided a spectrum of possible rational doses. Our Dose Band prediction method is based on a specific loss function, so it can easily be applied in various network and patient cases. Dose Band prediction towards a more robust plan QA and planning assistance. Table 1. The maximum interval of doses (percentage dose difference, %).
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Han B, Schmall J, Bal G, Khan S, Voronenko Y, Xu S, Shi L, Mitra A, Groll A, Sharma S, Ramos K, Shao L, Narayanan M, Olcott P, Kuduvalli G, Kovalchuk N, Surucu M. Characterization of Biology-Guided Radiotherapy Accuracy as a Function of PET Tracer Uptake. Int J Radiat Oncol Biol Phys 2023; 117:e668-e669. [PMID: 37785972 DOI: 10.1016/j.ijrobp.2023.06.2113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) To characterize the tracking capability and dosimetric accuracy of biology-guided radiotherapy (BgRT) under clinically relevant PET tracer uptake scenarios relative to the background. MATERIALS/METHODS A custom-made anthropomorphic phantom filled with a liquid 18F-FDG solution including two embedded fillable 22 mm diameter spherical structures mimicking GTV (= CTV) and OAR was coupled to motion stages to create an independent 3D respiratory motion with 22 mm maximum range for target and a 5 mm 1D sinusoidal motion in the OAR. The biology-tracking zone (BTZ) was generated by adding 5 mm margin to the motion extent. The three BgRT scenarios studied were representative of tumors with good (8:1), borderline (4:1) and undesired (2:1) PET biodistributions compared to background. The clinical safety limit of BgRT uses Activity Concentration within the BTZ (AC ≥ 5 kBq/ml) and Normalized Target Signal as a contrast metric (NTS ≧ 2.7 for planning and ≧ 2 for delivery). The BgRT deliveries were repeated 3 times with radiochromic film and integrated ion chamber capturing the target and OAR doses. Tracked dosimetry was assessed using a margin-loss calculation defined as the maximum linear difference in distance between the planned and delivered 97% prescription iso-dose lines. RESULTS The imaging-only PET images used to create BgRT plans had an AC of 7.0, 5.3, and 1.6 kBq/ml with an NTS of 6.8, 5.3, and 1.8 for 8:1, 4:1, and 2:1 concentrations, respectively. Qualitatively, the target was not visible on the planning PET images 2:1 loading scenario. At delivery, the mean pre-scan activity concentrations were 6.8, 4.7, and 3.7 kBq/ml with corresponding mean NTS of 3.7, 2.6, 1.5 for 8:1, 4:1 and 2:1 deliveries. The pre-scan values of AC or NTS did not satisfy the clinical system safety limits for 4:1 and 2:1 ratio experiments, but the engineering software allowed for the delivery to capture the resulting doses. The deliveries showed a prescription dose coverage to the CTV of 100% for the 8:1 and 4:1 cases, but 88% for the 2:1 case. When compared to the planned dose values, the delivered minimum doses were -7.6%, -8.6% and -10.9%, whereas the maximum dose differences in CTV were 1.2%, 0% and -4.8% of the planned dose distributions of the 8:1, 4:1 and 2:1 cases, respectively. Calculated margin losses were -2.3, -3.8, and -5.5 mm, for the 8:1, 4:1, and 2:1 cases, respectively. The maximum OAR doses were less than the maximum doses predicted on the bounded DVH curves for all scenarios. CONCLUSION With sufficient tracer uptake in the target, BgRT can deliver tracked dosimetry for targets with a large respiratory motion profile. Both the good BgRT candidate and borderline cases produced clinically acceptable delivered doses, even though the borderline case was flagged by the clinical system safety checks. As expected, the delivered BgRT dose distributions were suboptimal with reduced tumor over background PET contrast.
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