64 research outputs found

    2D Slice-driven Physics-based 3D Motion Estimation Framework for Pancreatic Radiotherapy

    Full text link
    Pancreatic diseases are difficult to treat with high doses of radiation, as they often present both periodic and aperiodic deformations. Nevertheless, we expect that these difficulties can be overcome, and treatment results may be improved with the practical use of a device that can capture 2D slices of organs during irradiation. However, since only a few 2D slices can be taken, the 3D motion needs to be estimated from partially observed information. In this study, we propose a physics-based framework for estimating the 3D motion of organs, regardless of periodicity, from motion information obtained by 2D slices in one or more directions and a regression model that estimates the accuracy of the proposed framework to select the optimal slice. Using information obtained by slice-to-slice registration and setting the surrounding organs as boundaries, the framework drives the physical models for estimating 3D motion. The R2 score of the proposed regression model was greater than 0.9, and the RMSE was 0.357 mm. The mean errors were 5.11 ±\pm 1.09 mm using an axial slice and 2.13 ±\pm 0.598 mm using concurrent axial, sagittal, and coronal slices. Our results suggest that the proposed framework is comparable to volume-to-volume registration, and is feasible

    Impact of pathological tumor stage for salvage radiotherapy after radical prostatectomy in patients with prostate-specific antigen < 1.0 ng/ml

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>To evaluate prognostic factors in salvage radiotherapy (RT) for patients with pre-RT prostate-specific antigen (PSA) < 1.0 ng/ml.</p> <p>Methods</p> <p>Between January 2000 and December 2009, 102 patients underwent salvage RT for biochemical failure after radical prostatectomy (RP). Re-failure of PSA after salvage RT was defined as a serum PSA value of 0.2 ng/ml or more above the postradiotherapy nadir followed by another higher value, a continued rise in serum PSA despite salvage RT, or initiation of systemic therapy after completion of salvage RT. Biochemical relapse-free survival (bRFS) was estimated using the Kaplan-Meier method. Multivariate analysis was performed using the Cox proportional hazards regression model.</p> <p>Results</p> <p>The median follow-up period was 44 months (range, 11-103 months). Forty-three patients experienced PSA re-failure after salvage RT. The 4-year bRFS was 50.9% (95% confidence interval [95% CI]: 39.4-62.5%). In the log-rank test, pT3-4 (p < 0.001) and preoperative PSA (p = 0.037) were selected as significant factors. In multivariate analysis, only pT3-4 was a prognostic factor (hazard ratio: 3.512 [95% CI: 1.535-8.037], p = 0.001). The 4-year bRFS rates for pT1-2 and pT3-4 were 79.2% (95% CI: 66.0-92.3%) and 31.7% (95% CI: 17.0-46.4%), respectively.</p> <p>Conclusions</p> <p>In patients who have received salvage RT after RP with PSA < 1.0 ng/ml, pT stage and preoperative PSA were prognostic factors of bRFS. In particular, pT3-4 had a high risk for biochemical recurrence after salvage RT.</p

    Enhanced in vivo osteogenesis by nanocarrier-fused bone morphogenetic protein-4

    Get PDF
    Purpose: Bone defects and nonunions are major clinical skeletal problems. Growth factors are commonly used to promote bone regeneration; however, the clinical impact is limited because the factors do not last long at a given site. The introduction of tissue engineering aimed to deter the diffusion of these factors is a promising therapeutic strategy. The purpose of the present study was to evaluate the in vivo osteogenic capability of an engineered bone morphogenetic protein-4 (BMP4) fusion protein. Methods: BMP4 was fused with a nanosized carrier, collagen-binding domain (CBD), derived from fibronectin. The stability of the CBD-BMP4 fusion protein was examined in vitro and in vivo. Osteogenic effects of CBD-BMP4 were evaluated by computer tomography after intramedullary injection without a collagen-sponge scaffold. Recombinant BMP-4, CBD, or vehicle were used as controls. Expressions of bone-related genes and growth factors were compared among the groups. Osteogenesis induced by CBD-BMP4, BMP4, and CBD was also assessed in a bone-defect model. Results: In vitro, CBD-BMP4 was retained in a collagen gel for at least 7 days while BMP4 alone was released within 3 hours. In vivo, CBD-BMP4 remained at the given site for at least 2 weeks, both with or without a collagen-sponge scaffold, while BMP4 disappeared from the site within 3 days after injection. CBD-BMP4 induced better bone formation than BMP4 did alone, CBD alone, and vehicle after the intramedullary injection into the mouse femur. -Bone-related genes and growth factors were expressed at higher levels in CBD-BMP4-treated mice than in all other groups, including BMP4-treated mice. Finally, CBD-BMP4 potentiated more bone formation than did controls, including BMP4 alone, when applied to cranial bone defects without a collagen scaffold. Conclusion: Altogether, nanocarrier-CBD enhanced the retention of BMP4 in the bone, thereby promoting augmented osteogenic responses in the absence of a scaffold. These results suggest that CBD-BMP4 may be clinically useful in facilitating bone formation

    Defining Hypo-Methylated Regions of Stem Cell-Specific Promoters in Human iPS Cells Derived from Extra-Embryonic Amnions and Lung Fibroblasts

    Get PDF
    BACKGROUND: Human induced pluripotent stem (iPS) cells are currently used as powerful resources in regenerative medicine. During very early developmental stages, DNA methylation decreases to an overall low level at the blastocyst stage, from which embryonic stem cells are derived. Therefore, pluripotent stem cells, such as ES and iPS cells, are considered to have hypo-methylated status compared to differentiated cells. However, epigenetic mechanisms of "stemness" remain unknown in iPS cells derived from extra-embryonic and embryonic cells. METHODOLOGY/PRINCIPAL FINDINGS: We examined genome-wide DNA methylation (24,949 CpG sites covering 1,3862 genes, mostly selected from promoter regions) with six human iPS cell lines derived from human amniotic cells and fetal lung fibroblasts as well as two human ES cell lines, and eight human differentiated cell lines using Illumina's Infinium HumanMethylation27. A considerable fraction (807 sites) exhibited a distinct difference in the methylation level between the iPS/ES cells and differentiated cells, with 87.6% hyper-methylation seen in iPS/ES cells. However, a limited fraction of CpG sites with hypo-methylation was found in promoters of genes encoding transcription factors. Thus, a group of genes becomes active through a decrease of methylation in their promoters. Twenty-three genes including SOX15, SALL4, TDGF1, PPP1R16B and SOX10 as well as POU5F1 were defined as genes with hypo-methylated SS-DMR (Stem cell-Specific Differentially Methylated Region) and highly expression in iPS/ES cells. CONCLUSIONS/SIGNIFICANCE: We show that DNA methylation profile of human amniotic iPS cells as well as fibroblast iPS cells, and defined the SS-DMRs. Knowledge of epigenetic information across iPS cells derived from different cell types can be used as a signature for "stemness" and may allow us to screen for optimum iPS/ES cells and to validate and monitor iPS/ES cell derivatives for human therapeutic applications

    Outcomes after stereotactic body radiotherapy for lung tumors, with emphasis on comparison of primary lung cancer and metastatic lung tumors

    Get PDF
    BACKGROUND: The goal of this study was to determine the prognostic factors associated with an improved overall outcome after stereotactic body radiotherapy (SBRT) for primary lung cancer and metastatic lung tumors. METHODS: A total of 229 lung tumors in 201 patients were included in the study. SBRT of 45 Gy in 3 fractions, 48 Gy in 4 fractions, 60 Gy in 8 fractions or 60 Gy in 15 fractions was typically used to treat 172 primary lungs cancer in 164 patients and 57 metastatic lung tumors in 37 patients between January 2001 and December 2011. Prognostic factors for local control (LC) and overall survival (OS) were analyzed using a Cox proportional hazards model. RESULTS: The median biologically effective dose was 105.6 Gy based on alpha/beta = 10 (BED10). The median follow-up period was 41.9 months. The 3-year LC and OS rates were 72.5% and 60.9%, and the 5-year LC and OS rates were 67.8% and 38.1%, respectively. Radiation pneumonitis of grades 2, 3 and 5 occurred in 22 petients, 6 patients and 1 patient, respectively. Multivariate analyses revealed that tumor origin (primary lung cancer or metastatic lung tumor, p < 0.001), tumor diameter (p = 0.005), BED10 (p = 0.029) and date of treatment (p = 0.011) were significant independent predictors for LC and that gender (p = 0.012), tumor origin (p = 0.001) and tumor diameter (p < 0.001) were significant independent predictors for OS. CONCLUSIONS: SBRT resulted in good LC and tolerable treatment-related toxicities. Tumor origin and tumor diameter are significant independent predictors for both overall survival and local control

    CCN3 and bone marrow cells

    Get PDF
    CCN3 expression was observed in a broad variety of tissues from the early stage of development. However, a kind of loss of function in mice (CCN3 del VWC domain -/-) demonstrated mild abnormality, which indicates that CCN3 may not be critical for the normal embryogenesis as a single gene. The importance of CCN3 in bone marrow environment becomes to be recognized by the studies of hematopoietic stem cells and Chronic Myeloid Leukemia cells. CCN3 expression in bone marrow has been denied by several investigations, but we found CCN3 positive stromal and hematopoietic cells at bone extremities with a new antibody although they are a very few populations. We investigated the expression pattern of CCN3 in the cultured bone marrow derived mesenchymal stem cells and found its preference for osteogenic differentiation. From the analyses of in vitro experiment using an osteogenic mesenchymal stem cell line, Kusa-A1, we found that CCN3 downregulates osteogenesis by two different pathways; suppression of BMP and stimulation of Notch. Secreted CCN3 from Kusa cells inhibited the differentiation of osteoblasts in separate culture, which indicates the paracrine manner of CCN3 activity. CCN3 may also affect the extracellular environment of the niche for hematopoietic stem cells

    Risk factors for CAR-T cell manufacturing failure among DLBCL patients: A nationwide survey in Japan

    Get PDF
    CAR-T細胞製造を成功させるためのレシピ --アフェレーシス前の下ごしらえでの工夫--. 京都大学プレスリリース. 2023-04-27.For successful chimeric antigen receptor T (CAR-T) cell therapy, CAR-T cells must be manufactured without failure caused by suboptimal expansion. In order to determine risk factors for CAR-T cell manufacturing failure, we performed a nationwide cohort study in Japan and analysed patients with diffuse large B-cell lymphoma (DLBCL) who underwent tisagenlecleucel production. We compared clinical factors between 30 cases that failed (7.4%) with those that succeeded (n = 378). Among the failures, the proportion of patients previously treated with bendamustine (43.3% vs. 14.8%; p < 0.001) was significantly higher, and their platelet counts (12.0 vs. 17.0 × 10⁴/μL; p = 0.01) and CD4/CD8 T-cell ratio (0.30 vs. 0.56; p < 0.01) in peripheral blood at apheresis were significantly lower than in the successful group. Multivariate analysis revealed that repeated bendamustine use with short washout periods prior to apheresis (odds ratio [OR], 5.52; p = 0.013 for ≥6 cycles with washout period of 3–24 months; OR, 57.09; p = 0.005 for ≥3 cycles with washout period of <3 months), low platelet counts (OR, 0.495 per 105/μL; p = 0.022) or low CD4/CD8 ratios (<one third) (OR, 3.249; p = 0.011) in peripheral blood at apheresis increased the risk of manufacturing failure. Manufacturing failure remains an obstacle to CAR-T cell therapy for DLBCL patients. Avoiding risk factors, such as repeated bendamustine administration without sufficient washout, and risk-adapted strategies may help to optimize CAR-T cell therapy for DLBCL patients

    Focal dose escalation using FDG-PET-guided intensity-modulated radiation therapy boost for postoperative local recurrent rectal cancer: a planning study with comparison of DVH and NTCP

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>To evaluate the safety of focal dose escalation to regions with standardized uptake value (SUV) >2.0 using intensity-modulated radiation therapy (IMRT) by comparison of radiotherapy plans using dose-volume histograms (DVHs) and normal tissue complication probability (NTCP) for postoperative local recurrent rectal cancer</p> <p>Methods</p> <p>First, we performed conventional radiotherapy with 40 Gy/20 fr. (CRT 40 Gy) for 12 patients with postoperative local recurrent rectal cancer, and then we performed FDG-PET/CT radiotherapy planning for those patients. We defined the regions with SUV > 2.0 as biological target volume (BTV) and made three boost plans for each patient: 1) CRT boost plan, 2) IMRT without dose-painting boost plan, and 3) IMRT with dose-painting boost plan. The total boost dose was 20 Gy. In IMRT with dose-painting boost plan, we increased the dose for BTV+5 mm by 30% of the prescribed dose. We added CRT boost plan to CRT 40 Gy (<it>summed plan 1</it>), IMRT without dose-painting boost plan to CRT 40 Gy (<it>summed plan 2</it>) and IMRT with dose-painting boost plan to CRT 40 Gy (<it>summed plan 3</it>), and we compared those plans using DVHs and NTCP.</p> <p>Results</p> <p>D<sub>mean </sub>of PTV-PET and that of PTV-CT were 26.5 Gy and 21.3 Gy, respectively. V<sub>50 </sub>of small bowel PRV in <it>summed plan 1 </it>was significantly higher than those in other plans ((<it>summed plan 1 </it>vs. <it>summed plan 2 </it>vs. <it>summed plan 3</it>: 47.11 ± 45.33 cm<sup>3 </sup>vs. 40.63 ± 39.13 cm<sup>3 </sup>vs. 41.25 ± 39.96 cm<sup>3</sup>(p < 0.01, respectively)). There were no significant differences in V<sub>30</sub>, V<sub>40</sub>, V<sub>60</sub>, D<sub>mean </sub>or NTCP of small bowel PRV.</p> <p>Conclusions</p> <p>FDG-PET-guided IMRT can facilitate focal dose-escalation to regions with SUV above 2.0 for postoperative local recurrent rectal cancer.</p
    corecore