Objective:To validate the effectiveness of the leaf position data of multi-leaf collimator (MLC) recorded in the Infinity medical linear accelerator log file (LF).Methods:In this study, the establishment of the film dose calibration curve involved two steps. Initially, the pixel values obtained from scanning the film were converted into net optical density values. Subsequently, a sixth-order polynomial fit was performed on the net optical density and dose data. The picket fence (PF) tests were performed on the electronic portal imaging device (EPID) and film, and the corresponding acquired PF test images were analyzed using the relative leaf travel distance, relative leaf position, relative leaf pair full-width half -maximum (FWHM), and relative leaf pair neighbor region width analysis index, and compared with the relevant results in LF. In addition, to investigate the effect of gravity on the recorded leaf position data by the Infinity medical linear accelerator LF, the above PF tests were executed at 0°, 90°, 180°, and 270° gantry angles, respectively. Intergroup differences were assessed with the Wilcoxon rank-sum test.Results:The film dose calibration curve demonstrated high goodness-of-fit, with a correlation coefficient ( R2) of 0.9994. Across all gantry angles, the dispersion of overall leaf position data for EBT3 film, EPID, and LF followed a consistent pattern based on four analysis metrics: EBT3 film > EPID > LF. Moreover, for each analysis metric, inter-tool differences in standard deviations of results were consistently below 0.1 mm, and this pattern was invariant to gantry angle. Conclusions:The leaf position data recorded in the Infinity medical linear accelerator LF have a high degree of accuracy, and can be used as reference for the actual position of the MLC leaf. Furthermore, gravitational forces exhibit negligible impact on leaf position data acquired via LF.

Objective:To prepare heparin (Hep)-modified gelatin methacryloyl (GelMA) microspheres and to investigate their application in liver-targeted delivery of adipose-derived mesenchymal stem cells (ADSCs).Methods:GelMA microspheres were modified with Hep to obtain GelMA-Hep microspheres. The surface morphology of the GelMA-Hep microspheres was observed by scanning electron microscopy. The changes of carbon atoms, nitrogen atoms and sulfur atoms on the surface of the GelMA-Hep microspheres were detected by X-ray photoelectron spectroscopy. The surface chemical group composition of the GelMA-Hep microspheres was analyzed by Fourier transform infrared spectrometer. The swelling properties of the GelMA-Hep microspheres were detected by water absorption swelling experiment. Human liver HL-7702 cells transfected with lentivirus were co-cultured with GelMA, GelMA-dopamine (GelMA-dop) and GelMA-Hep microspheres. The effects of microspheres on cell proliferation activity were evaluated by cell counting kit-8 method and live/dead cell staining experiment. The adhesion of microspheres to cells was observed by confocal microscopy. The GelMA-Hep microspheres loaded with ADSCs were injected into C57BL/6 mice through the tail vein, and its efficiency of liver-targeted delivery of ADSCs was observed by a small animal in vivo imaging system. The data were compared by independent sample t test or one-way analysis of variance. Results:The GelMA-Hep microspheres were prepared by modifying the GelMA microspheres with Hep. Compared with the GelMA microspheres, the size of the GelMA-Hep microspheres did not change significantly, and the surface did not collapse and showed some crystalline particles. The binding energy of sulfur atoms on the surface of the GelMA-Hep microspheres increased from 166 eV to 168 eV. On the surface of the GelMA-Hep microspheres, the characteristic peaks of sulfonic acid and sulfate groups of Hep were detected at 1 490 cm ?1 and from 1 135 cm ?1 to 1 050 cm ?1, respectively. The swelling rate of the GelMA-dop microspheres was uniform, while the swelling rate of the GelMA microspheres and the GelMA-Hep microsphere was quite different, but the final swelling mass of the three microspheres tended to be consistent at 5 min. After 12, 24, 36 and 48 h of culture, the relative proliferation of cells in the GelMA-Hep group (1.61±0.29, 1.78±0.05, 2.27±0.08, 2.26±0.33) were higher than those in the negative control group (1.00±0.00, 1.28±0.06, 1.39±0.02, 1.41±0.04) (all P<0.05). After 36 h of culture, the relative proliferation of cells in the GelMA-Hep group was higher than that in the GelMA-dop group (1.63±0.21), with significant difference ( P<0.05). Live/dead cell staining experiment showed that after 12 h of cell culture in the GelMA-Hep group, only a few microspheres had cell adhesion; at 24 h, the cells were densely distributed on the surface of the microspheres. After 36 h, the number of cells increased further. At 48 h, live cells were distributed throughout the microspheres. Confocal microscopy showed that after 24 h of culture, cells adhered to the surface of the microspheres in the GelMA-Hep group and showed a stretched morphology. The liver of the GelMA-Hep+ADSCs group showed strong fluorescence at 0.5 h, and the fluorescence brightness continued to 48.0 h. The number of ADSCs reaching the liver was more than that of ADSCs group and GelMA+ADSCs group. Conclusions:GelMA-Hep microspheres were successfully prepared, which can improve the efficiency of liver-targeted delivery of ADSCs.

Inverse Compton scattering X-rays are commonly generated by the collision of the incident relativistic high-energy electrons with the low-energy photons of laser pulses. Compared with the X-rays from bremsstrahlung radiation, which are often used in clinical settings, inverse Compton X-rays have unique advantages in radiological diagnosis and treatment due to their distinctive physical properties. In these years, the demand of precision radiotherapy technology has been increasingly emphasized. Inverse Compton X-rays may provide such a promising path for the development of precision radiotherapy. However, only a few facilities worldwide can achieve the generation of inverse Compton X-rays, and relevant studies in the field of radiation therapy are also in the exploratory stage. In this article, recent research progress at home and abroad were reviewed to introduce the ways of inverse Compton X-rays generation as well as their characteristics and advantages in radiation physics, aiming to provide reference for evaluating their application values and prospects in radiation therapy.

Objective:To investigate the impact of different target sites, number of treatments, and age on setup errors in dual-isocenter radiotherapy for breast cancer, and to provide a basis for planning target volume (PTV) margin expansion.Methods:A retrospective analysis was conducted on data from 15 patients with left-sided breast cancer who underwent dual-isocenter breath-hold radiotherapy in the Department of Radiotherapy Oncology at the Second Hospital of Hebei Medical University from May 2021 to May 2023. Setup errors were acquired using a Varian TrueBeam STX linear accelerator. Patients were grouped by target site (supraclavicular/chest wall), treatment phase (early/late), and age (younger/older). Non-parametric tests were used to analyze differences in setup errors in : vertical (Vrt), longitudinal (Lng), lateral (Lat) directions, and pitch, roll, and rotation (Rtn) angles. The formula proposed by van Herk was applied to calculate PTV margins.Results:The Vrt direction setup error in the supraclavicular region (0.2 cm) was smaller than that in the chest wall region (0.26 cm), but errors and margin expansions in other directions were larger ( P<0.05 for Lng and Lat directions). No significant correlation was observed in Vrt direction errors between the two sites ( P=0.062), while significant correlations were found in the other directions and angles (all P<0.05). As treatment progressed, setup errors increased in the Vrt and Rtn directions for the supraclavicular region, and in the Vrt, Lng, Lat directions and Rtn angle for the chest wall region. Among these, only the increase in Lat direction error for the chest wall region was statistically significant ( P=0.028). The PTV margins in the late phase group (except for the Lat direction of the supraclavicular region) were greater than or equal to those in the early phase group. Elderly patients had significantly larger setup errors than younger patients in Vrt, Lng, and Lat directions for the supraclavicular region, as well as in Vrt and Lat directions for the chest wall region (all P<0.05). Conclusions:In dual-isocenter radiotherapy for breast cancer, the supraclavicular region requires larger PTV margins than the chest wall region, and elderly patients require greater margins overall. Mid-course rescanning is recommended. If cone-beam CT guidance cannot be ensured for every session, expansion of PTV margins should be considered for the supraclavicular region and elderly patients to reduce the risk of geographic miss.

Objective:To construct an early rehabilitation exercise program for patients with agoraphobia after total knee arthroplasty (TKA) to provide guidance for orthopedic rehabilitation nursing practice.Methods:The first draft of an early rehabilitation exercise program for patients with agoraphobia after TKA was developed through literature search, semi-structured interviews, and group discussions. From November to December 2023, 20 experts from nine provinces and centrally administered municipalities were selected for two rounds of expert consultation using the Delphi method to form the final draft of the early rehabilitation exercise program for patients with agoraphobia after TKA.Results:In two rounds of consultation, the questionnaire recovery rates were 91.30% (21/23) and 95.24% (20/21), with authority coefficients of 0.92 and 0.96, and Kendall's coordination coefficients of 0.28 and 0.34, respectively ( P<0.05). After the second round of consultation, the mean importance assignment scores for all levels of indicators ranged from 3.90 to 5.00, with coefficients of variation ranging from 0 to 0.20. The finalized early rehabilitation exercise program for patients with agoraphobia after TKA contained two parts, including the preface and the main text, and the main text consisted of five first-level items, 21 second-level items, and 35 third-level items. Conclusions:The content of the early rehabilitation exercise program for patients with agoraphobia after TKA is scientific, reasonable, comprehensive, practical and targeted, which can provide a basis for clinical medical and nursing personnel to guide the early rehabilitation exercise for patients with agoraphobia after TKA.

Objective:To construct an early rehabilitation exercise program for patients with agoraphobia after total knee arthroplasty (TKA) to provide guidance for orthopedic rehabilitation nursing practice.Methods:The first draft of an early rehabilitation exercise program for patients with agoraphobia after TKA was developed through literature search, semi-structured interviews, and group discussions. From November to December 2023, 20 experts from nine provinces and centrally administered municipalities were selected for two rounds of expert consultation using the Delphi method to form the final draft of the early rehabilitation exercise program for patients with agoraphobia after TKA.Results:In two rounds of consultation, the questionnaire recovery rates were 91.30% (21/23) and 95.24% (20/21), with authority coefficients of 0.92 and 0.96, and Kendall's coordination coefficients of 0.28 and 0.34, respectively ( P<0.05). After the second round of consultation, the mean importance assignment scores for all levels of indicators ranged from 3.90 to 5.00, with coefficients of variation ranging from 0 to 0.20. The finalized early rehabilitation exercise program for patients with agoraphobia after TKA contained two parts, including the preface and the main text, and the main text consisted of five first-level items, 21 second-level items, and 35 third-level items. Conclusions:The content of the early rehabilitation exercise program for patients with agoraphobia after TKA is scientific, reasonable, comprehensive, practical and targeted, which can provide a basis for clinical medical and nursing personnel to guide the early rehabilitation exercise for patients with agoraphobia after TKA.

Inverse Compton scattering X-rays are commonly generated by the collision of the incident relativistic high-energy electrons with the low-energy photons of laser pulses. Compared with the X-rays from bremsstrahlung radiation, which are often used in clinical settings, inverse Compton X-rays have unique advantages in radiological diagnosis and treatment due to their distinctive physical properties. In these years, the demand of precision radiotherapy technology has been increasingly emphasized. Inverse Compton X-rays may provide such a promising path for the development of precision radiotherapy. However, only a few facilities worldwide can achieve the generation of inverse Compton X-rays, and relevant studies in the field of radiation therapy are also in the exploratory stage. In this article, recent research progress at home and abroad were reviewed to introduce the ways of inverse Compton X-rays generation as well as their characteristics and advantages in radiation physics, aiming to provide reference for evaluating their application values and prospects in radiation therapy.

Objective:To investigate the impact of different target sites, number of treatments, and age on setup errors in dual-isocenter radiotherapy for breast cancer, and to provide a basis for planning target volume (PTV) margin expansion.Methods:A retrospective analysis was conducted on data from 15 patients with left-sided breast cancer who underwent dual-isocenter breath-hold radiotherapy in the Department of Radiotherapy Oncology at the Second Hospital of Hebei Medical University from May 2021 to May 2023. Setup errors were acquired using a Varian TrueBeam STX linear accelerator. Patients were grouped by target site (supraclavicular/chest wall), treatment phase (early/late), and age (younger/older). Non-parametric tests were used to analyze differences in setup errors in : vertical (Vrt), longitudinal (Lng), lateral (Lat) directions, and pitch, roll, and rotation (Rtn) angles. The formula proposed by van Herk was applied to calculate PTV margins.Results:The Vrt direction setup error in the supraclavicular region (0.2 cm) was smaller than that in the chest wall region (0.26 cm), but errors and margin expansions in other directions were larger ( P<0.05 for Lng and Lat directions). No significant correlation was observed in Vrt direction errors between the two sites ( P=0.062), while significant correlations were found in the other directions and angles (all P<0.05). As treatment progressed, setup errors increased in the Vrt and Rtn directions for the supraclavicular region, and in the Vrt, Lng, Lat directions and Rtn angle for the chest wall region. Among these, only the increase in Lat direction error for the chest wall region was statistically significant ( P=0.028). The PTV margins in the late phase group (except for the Lat direction of the supraclavicular region) were greater than or equal to those in the early phase group. Elderly patients had significantly larger setup errors than younger patients in Vrt, Lng, and Lat directions for the supraclavicular region, as well as in Vrt and Lat directions for the chest wall region (all P<0.05). Conclusions:In dual-isocenter radiotherapy for breast cancer, the supraclavicular region requires larger PTV margins than the chest wall region, and elderly patients require greater margins overall. Mid-course rescanning is recommended. If cone-beam CT guidance cannot be ensured for every session, expansion of PTV margins should be considered for the supraclavicular region and elderly patients to reduce the risk of geographic miss.

Objective:To validate the effectiveness of the leaf position data of multi-leaf collimator (MLC) recorded in the Infinity medical linear accelerator log file (LF).Methods:In this study, the establishment of the film dose calibration curve involved two steps. Initially, the pixel values obtained from scanning the film were converted into net optical density values. Subsequently, a sixth-order polynomial fit was performed on the net optical density and dose data. The picket fence (PF) tests were performed on the electronic portal imaging device (EPID) and film, and the corresponding acquired PF test images were analyzed using the relative leaf travel distance, relative leaf position, relative leaf pair full-width half -maximum (FWHM), and relative leaf pair neighbor region width analysis index, and compared with the relevant results in LF. In addition, to investigate the effect of gravity on the recorded leaf position data by the Infinity medical linear accelerator LF, the above PF tests were executed at 0°, 90°, 180°, and 270° gantry angles, respectively. Intergroup differences were assessed with the Wilcoxon rank-sum test.Results:The film dose calibration curve demonstrated high goodness-of-fit, with a correlation coefficient ( R2) of 0.9994. Across all gantry angles, the dispersion of overall leaf position data for EBT3 film, EPID, and LF followed a consistent pattern based on four analysis metrics: EBT3 film > EPID > LF. Moreover, for each analysis metric, inter-tool differences in standard deviations of results were consistently below 0.1 mm, and this pattern was invariant to gantry angle. Conclusions:The leaf position data recorded in the Infinity medical linear accelerator LF have a high degree of accuracy, and can be used as reference for the actual position of the MLC leaf. Furthermore, gravitational forces exhibit negligible impact on leaf position data acquired via LF.

The neurovascular unit (NVU) is highly responsible for cerebral homeostasis and its dysfunction emerges as a critical contributor to Alzheimer's disease (AD) pathology. Hence, rescuing NVU dysfunction might be a viable approach to AD treatments. Here, we fabricated a self-regulated muti-functional nano-modulator (siR/PIO@RP) that can intelligently navigate to damaged blood-brain barrier and release therapeutical cargoes for synergetic AD therapy. The resulting siR/PIO@RP enables self-regulation of its distribution in accordance with the physio/pathological state (low/high RAGE expression) of the target site via a feedback loop. siR/PIO@RP is capable of performing intricate tasks and goes beyond the capabilities of single-target therapeutic agents utilized in AD therapy, such as reducing cerebral Aβ load, relieving neuroinflammation, and alleviating the dysfunction of NVU. Overall, the current study provides proof of concept that normalizing NVU holds promise as a means of alleviating AD symptoms.