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Journal of Nuclear Cardiology :... Feb 2024
Topics: Humans; Stroke Volume; Heart; Magnetic Resonance Imaging; Positron-Emission Tomography
PubMed: 38245396
DOI: 10.1016/j.nuclcard.2024.101795 -
Acta Oncologica (Stockholm, Sweden) Nov 2023Analyses of clinical outcomes following radiotherapy (RT) have advanced our understanding of fundamental radiobiological characteristics in head and neck squamous cell...
BACKGROUND
Analyses of clinical outcomes following radiotherapy (RT) have advanced our understanding of fundamental radiobiological characteristics in head and neck squamous cell carcinoma (HNSCC). Low fractionation sensitivity appears to be a common feature, as well as susceptibility to changes in overall treatment time (OTT). Large tumors should be harder to cure if a successful RT requires the sterilization of all clonogenic cells. Congruently, primary tumor volume has proven to be an important parameter. However, most findings come from an era when p16-negative HNSCC was the dominant tumor type. HPV-associated, p16-positive, oropharyngeal tumors (OPSCC) are more radiosensitive and have better outcome. The current study aims to investigate the role of primary tumor volume, OTT and estimate α-ratio for p16-positive OPSCC, and to quantify the differences in radiosensitivity depending on p16-status.
METHODS
A cohort of 523 patients treated with RT was studied using a tumor control probability (TCP)-model that incorporates primary tumor volume (V) raised to an exponent , OTT and α-estimation. The significance of V was also investigated in Cox-regression models.
RESULTS
In the p16-positive cohort ( = 433), the volume exponent was 1.44 (95%CI 1.06-1.91), compared to 0.90 (0.54-1.32) for p16-negative tumors ( = 90). Hazard ratios per tumor volume doubling were 2.37 (1.72-3.28) and 1.83 (1.28-2.62) for p16-positive and p16-negative, respectively. The estimated α-ratio was 9.7 Gy (-2.3-21.6), and a non-significant daily loss of 0.30 Gy (-0.17-0.92) was found. An additional dose of 6.8 Gy (interquartile range 4.8-9.1) may theoretically counteract the more radioresistant behavior of p16-negative tumors.
CONCLUSION
Primary tumor volume plays a crucial role in predicting local tumor response, particularly in p16-positive OPSCC. The estimated α/β-ratio for p16-positive oropharyngeal tumors aligns with previous HNSCC studies, whereas the impact of prolonged OTT was slightly less than previously reported. The differences in radiosensitivity depending on p16-status were quantified. The findings should be validated in independent cohorts.
Topics: Humans; Squamous Cell Carcinoma of Head and Neck; Carcinoma, Squamous Cell; Tumor Burden; Oropharyngeal Neoplasms; Head and Neck Neoplasms; Papillomavirus Infections; Cyclin-Dependent Kinase Inhibitor p16; Prognosis
PubMed: 37682690
DOI: 10.1080/0284186X.2023.2251084 -
Bioengineering (Basel, Switzerland) Oct 2023Clinical indications for adipose tissue therapy are expanding towards a regenerative-based approach. Adipose-derived stromal vascular fraction consists of extracellular... (Review)
Review
Clinical indications for adipose tissue therapy are expanding towards a regenerative-based approach. Adipose-derived stromal vascular fraction consists of extracellular matrix and all nonadipocyte cells such as connective tissue cells including fibroblasts, adipose-derived stromal cells (ASCs) and vascular cells. Tissue stromal vascular fraction (tSVF) is obtained by mechanical fractionation, forcing adipose tissue through a device with one or more small hole(s) or cutting blades between syringes. The aim of this scoping review was to assess the efficacy of mechanical fractionation procedures to obtain tSVF. In addition, we provide an overview of the clinical, that is, therapeutic, efficacy of tSVF isolated by mechanical fraction on skin rejuvenation, wound healing and osteoarthritis. Procedures to obtain tissue stromal vascular fraction using mechanical fractionation and their associated validation data were included for comparison. For clinical outcome comparison, both animal and human studies that reported results after tSVF injection were included. We categorized mechanical fractionation procedures into filtration ( = 4), centrifugation ( = 8), both filtration and centrifugation ( = 3) and other methods ( = 3). In total, 1465 patients and 410 animals were described in the included clinical studies. tSVF seems to have a more positive clinical outcome in diseases with a high proinflammatory character such as osteoarthritis or (disturbed) wound healing, in comparison with skin rejuvenation of aging skin. Isolation of tSVF is obtained by disruption of adipocytes and therefore volume is reduced. Procedures consisting of centrifugation prior to mechanical fractionation seem to be most effective in volume reduction and thus isolation of tSVF. tSVF injection seems to be especially beneficial in clinical applications such as osteoarthritis or wound healing. Clinical application of tSVF appeared to be independent of the preparation procedure, which indicates that current methods are highly versatile.
PubMed: 37892905
DOI: 10.3390/bioengineering10101175 -
Seminars in Radiation Oncology Jul 2023Improvements in radiotherapy delivery have enabled higher therapeutic doses and improved efficacy, contributing to the growing number of long-term cancer survivors.... (Review)
Review
Improvements in radiotherapy delivery have enabled higher therapeutic doses and improved efficacy, contributing to the growing number of long-term cancer survivors. These survivors are at risk of developing late toxicity from radiotherapy, and the inability to predict who is most susceptible results in substantial impact on quality of life and limits further curative dose escalation. A predictive assay or algorithm for normal tissue radiosensitivity would allow more personalized treatment planning, reducing the burden of late toxicity, and improving the therapeutic index. Progress over the last 10 years has shown that the etiology of late clinical radiotoxicity is multifactorial and informs development of predictive models that combine information on treatment (eg, dose, adjuvant treatment), demographic and health behaviors (eg, smoking, age), co-morbidities (eg, diabetes, collagen vascular disease), and biology (eg, genetics, ex vivo functional assays). AI has emerged as a useful tool and is facilitating extraction of signal from large datasets and development of high-level multivariable models. Some models are progressing to evaluation in clinical trials, and we anticipate adoption of these into the clinical workflow in the coming years. Information on predicted risk of toxicity could prompt modification of radiotherapy delivery (eg, use of protons, altered dose and/or fractionation, reduced volume) or, in rare instances of very high predicted risk, avoidance of radiotherapy. Risk information can also be used to assist treatment decision-making for cancers where efficacy of radiotherapy is equivalent to other treatments (eg, low-risk prostate cancer) and can be used to guide follow-up screening in instances where radiotherapy is still the best choice to maximize tumor control probability. Here, we review promising predictive assays for clinical radiotoxicity and highlight studies that are progressing to develop an evidence base for clinical utility.
Topics: Male; Humans; Quality of Life; Prostatic Neoplasms; Dose Fractionation, Radiation; Radiation Tolerance; Radiation Injuries; Radiotherapy Dosage
PubMed: 37331785
DOI: 10.1016/j.semradonc.2023.03.010 -
Scientific Data May 2024Infra-fraction motion of the prostate was recorded during 3.423 fractions of image guided radiotherapy (IGRT) in 191 patients, 14 of which were treated by intensity...
Infra-fraction motion of the prostate was recorded during 3.423 fractions of image guided radiotherapy (IGRT) in 191 patients, 14 of which were treated by intensity modulated radiation therapy (IMRT), and 177 of which were treated by volumetric arc therapy (VMAT). The prostate was imaged by three-dimensional and time-resolved transperineal ultrasound (4D-US) of type Clarity by Elekta AB, Stockholm, Sweden. The prostate volume was registered and the prostate position (center of volume) was recorded at a frequency of 2.0 samples per second. This raw data set contains a total of 1.985.392 prostate and patient couch positions over a time span of 272 hours, 52 minutes and 34 seconds of life radiotherapy as exported by the instrument software. This data set has been used for the validation of models of prostate intra-fraction motion and for the estimation of the dosimetric impact of actual intra-fraction motion on treatment quality and side effects. We hope that this data set may be reused by other groups for similar purposes.
Topics: Humans; Male; Movement; Prostate; Prostatic Neoplasms; Radiotherapy, Image-Guided; Radiotherapy, Intensity-Modulated; Ultrasonography
PubMed: 38755158
DOI: 10.1038/s41597-024-03365-2 -
BMC Cardiovascular Disorders Sep 2023Highly accelerated compressed sensing cine has allowed for quantification of ventricular function in a single breath hold. However, compared to segmented breath hold... (Meta-Analysis)
Meta-Analysis
PURPOSE
Highly accelerated compressed sensing cine has allowed for quantification of ventricular function in a single breath hold. However, compared to segmented breath hold techniques, there may be underestimation or overestimation of LV volumes. Furthermore, a heterogeneous sample of techniques have been used in volunteers and patients for pre-clinical and clinical use. This can complicate individual comparisons where small, but statistically significant differences exist in left ventricular morphological and/or functional parameters. This meta-analysis aims to provide a comparison of conventional cine versus compressed sensing based reconstruction techniques in patients and volunteers.
METHODS
Two investigators performed systematic searches for eligible studies using PubMed/MEDLINE and Web of Science to identify studies published 1/1/2010-3/1/2021. Ultimately, 15 studies were included for comparison between compressed sensing cine and conventional imaging.
RESULTS
Compared to conventional cine, there were small, statistically significant overestimation of LV mass, underestimation of stroke volume and LV end diastolic volume (mean difference 2.65 g [CL 0.57-4.73], 2.52 mL [CL 0.73-4.31], and 2.39 mL [CL 0.07-4.70], respectively). Attenuated differences persisted across studies using prospective gating (underestimated stroke volume) and non-prospective gating (underestimation of stroke volume, overestimation of mass). There were no significant differences in LV volumes or LV mass with high or low acceleration subgroups in reference to conventional cine except slight underestimation of ejection fraction among high acceleration studies. Reduction in breath hold acquisition time ranged from 33 to 64%, while reduction in total scan duration ranged from 43 to 97%.
CONCLUSION
LV volume and mass assessment using compressed sensing CMR is accurate compared to conventional parallel imaging cine.
Topics: Humans; Magnetic Resonance Imaging; Heart; Heart Ventricles; Breath Holding; Magnetic Resonance Spectroscopy
PubMed: 37735355
DOI: 10.1186/s12872-023-03426-1 -
Physics in Medicine and Biology Aug 2023Radiation-induced cell death is a complex process influenced by physical, chemical and biological phenomena. Although consensus on the nature and the mechanism of the...
Radiation-induced cell death is a complex process influenced by physical, chemical and biological phenomena. Although consensus on the nature and the mechanism of the bystander effect were not yet made, the immune process presumably plays an important role in many aspects of the radiotherapy including the bystander effect. A mathematical model of immune response during and after radiation therapy is presented.Immune response of host body and immune suppression of tumor cells are modelled with four compartments in this study; viable tumor cells, T cell lymphocytes, immune triggering cells, and doomed cells. The growth of tumor was analyzed in two distinctive modes of tumor status (immune limited and immune escape) and its bifurcation condition.Tumors in the immune limited mode can grow only up to a finite size, named as terminal tumor volume analytically calculated from the model. The dynamics of the tumor growth in the immune escape mode is much more complex than the tumors in the immune limited mode especially when the status of tumor is close to the bifurcation condition. Radiation can kill tumor cells not only by radiation damage but also by boosting immune reaction.The model demonstrated that the highly heterogeneous dose distribution in spatially fractionated radiotherapy (SFRT) can make a drastic difference in tumor cell killing compared to the homogeneous dose distribution. SFRT cannot only enhance but also moderate the cell killing depending on the immune response triggered by many factors such as dose prescription parameters, tumor volume at the time of treatment and tumor characteristics. The model was applied to the lifted data of 67NR tumors on mice and a sarcoma patient treated multiple times over 1200 days for the treatment of tumor recurrence as a demonstration.
Topics: Mice; Animals; Neoplasms; Dose Fractionation, Radiation; Immunity; Radiotherapy
PubMed: 37459862
DOI: 10.1088/1361-6560/ace819 -
Plastic and Reconstructive Surgery Mar 2024Autologous fat grafting is frequently used for volume augmentation and tissue regeneration. The uniform physical and biological characteristics of fat grafts, however,...
BACKGROUND
Autologous fat grafting is frequently used for volume augmentation and tissue regeneration. The uniform physical and biological characteristics of fat grafts, however, limit their optimal effects in various situations. Subjecting fat tissue to different mechanical processes results in adipose-derived products with distinct biological components and physical features. The present study describes a novel facial fat-grafting strategy, adipose component transplantation (ACT), that yields different adipose products that can be applied to specific injection sites.
METHODS
All patients who underwent ACT were evaluated retrospectively. Fat tissue samples were fractionated into high-density fat, adipose matrix complex, stromal vascular fraction gel, and adipose collagen fragment, as described. Each of these fractions was processed and injected into indicated recipient sites. Additional SVF gel was cryopreserved and, if necessary, injected during the following 3 months. Patients were followed up after 1, 2, 3, and 6 months, and annually thereafter.
RESULTS
From March of 2020 to September of 2021, 78 patients underwent whole face fat grafting using the ACT strategy. All operations and secondary injections of cryopreserved SVF gel were uneventful. There were no major complications, and final aesthetic results were satisfactory in 91% of patients.
CONCLUSIONS
The ACT strategy allows specific adipose products to be applied to specific injection sites, as warranted. Adipose matrix complex is indicated for sufficient rigid support, high-density fat when large volumes are required, SVF gel for precise injection and cryopreservation, and ACF as mesotherapy for skin rejuvenation. The ACT strategy optimizes the biological functions and physical features of different adipose-derived products.
CLINICAL QUESTION/LEVEL OF EVIDENCE
Therapeutic, IV.
Topics: Humans; Retrospective Studies; Rejuvenation; Adipose Tissue; Wound Healing; Face
PubMed: 36988657
DOI: 10.1097/PRS.0000000000010483 -
Journal of the Science of Food and... Sep 2023Afidopyropen is a novel biorational insecticide for controlling piercing pests with great potential for application in tea gardens that can form the metabolite M440I007...
BACKGROUND
Afidopyropen is a novel biorational insecticide for controlling piercing pests with great potential for application in tea gardens that can form the metabolite M440I007 when utilized for crops. However, because of a lack of analytical method for afidopyropen and M440I007 in tea, there is no means of monitoring the residues. Therefore, method development, validation and simultaneous determination of afidopyropen and M440I007 in fresh tea leaves, dried tea and tea infusion is of prime significance.
RESULTS
A TPT cartridge-based method was developed for the solid phase extraction of afidopyropen and M440I007 from tea matrices. Extraction and clean-up conditions, including the composition, volume and temperature of elutions, were optimized to achieve the best results. Both targets were extracted using water and acetonitrile, with a water:acetonitrile (v/v) ratio of 4:10 for fresh leaves and 8:10 for dried tea, which were then cleaned and analyzed using ultraperformance liquid chromatography-tandem mass spectrometry. Both analytes demonstrated excellent linearity with a correlation coefficient above 0.998. The optimized analytical method offered limits of quantifications of 0.005, 0.005 and 0.002 mg kg (converted to dried tea) in fresh tea shoots, dried tea and tea infusion for both targets, respectively. Average recoveries of afidopyropen and M440I007 ranged from 79.0% to 101.5%, with relative standard deviations ≤ 14.7%.
CONCLUSION
The results showed that the method of determination for these insecticides in tea matrices was practical and efficient. © 2023 Society of Chemical Industry.
Topics: Tandem Mass Spectrometry; Tea; Insecticides; Chromatography, High Pressure Liquid; Solid Phase Extraction; Acetonitriles; Water
PubMed: 37144352
DOI: 10.1002/jsfa.12691 -
Physics and Imaging in Radiation... Oct 2023Automation is desirable for organ segmentation in radiotherapy. This study compared deep learning methods for auto-segmentation of organs-at-risk (OARs) and clinical...
BACKGROUND AND PURPOSE
Automation is desirable for organ segmentation in radiotherapy. This study compared deep learning methods for auto-segmentation of organs-at-risk (OARs) and clinical target volume (CTV) in prostate cancer patients undergoing fractionated magnetic resonance (MR)-guided adaptive radiation therapy. Models predicting dense displacement fields (DDFMs) between planning and fraction images were compared to patient-specific (PSM) and baseline (BM) segmentation models.
MATERIALS AND METHODS
A dataset of 92 patients with planning and fraction MR images (MRIs) from two institutions were used. DDFMs were trained to predict dense displacement fields (DDFs) between the planning and fraction images, which were subsequently used to propagate the planning contours of the bladder, rectum, and CTV to the daily MRI. The training was performed either with true planning-fraction image pairs or with planning images and their counterparts deformed by known DDFs. The BMs were trained on 53 planning images, while to generate PSMs, the BMs were fine-tuned using the planning image of a given single patient. The evaluation included Dice similarity coefficient (DSC), the average (HD) and the 95th percentile (HD) Hausdorff distance (HD).
RESULTS
The DDFMs with DSCs for bladder/rectum of 0.76/0.76 performed worse than PSMs (0.91/0.90) and BMs (0.89/0.88). The same trend was observed for HDs. For CTV, DDFM and PSM performed similarly yielding DSCs of 0.87 and 0.84, respectively.
CONCLUSIONS
DDFMs were found suitable for CTV delineation after rigid alignment. However, for OARs they were outperformed by PSMs, as they predicted only limited deformations even in the presence of substantial anatomical changes.
PubMed: 37928618
DOI: 10.1016/j.phro.2023.100498