Objective To propose and validate a decomposition method based on half-projection reconstruction for dual-energy cone beam CT(DE CBCT),thereby providing a potentially feasible low-dose imaging solution for anatomical monitoring and dose reconstruction optimization in adaptive radiotherapy.Methods Dual-energy scans were performed on a Gammex phantom using the on-board kilovoltage CBCT system of a VitalBeam accelerator at acquisition frame rates of 15 and 7 frames per second(f/s).Images were reconstructed from the projection data,and dual-energy decomposition was applied to the 7 f/s dual-energy images to derive relative electron density(RED)and stopping power ratio(SPR)using weighted formulas and empirical functions,followed by accuracy evaluation.Additionally,the weighted CT dose index was calculated for different scanning parameters.Results Dual-energy decomposition effectively suppressed image artifacts,with RED and SPR errors remaining below 2.82%and 2.56%,respectively.Compared with the traditional dual-scan method which required high-and low-energy acquisitions,the weighted CT dose index of the half-projection DE CBCT was reduced by 11.60 mGy(a 52.90%reduction).Furthermore,it was 2.58 mGy lower than the dose of the full-projection high-energy CBCT alone(a 19.98%reduction)and only 1.31 mGy higher than that of the low-energy CBCT(a 14.52%increase).Conclusion The proposed method effectively suppresses image artifacts while maintaining high accuracy in RED and SPR under low radiation dose conditions,demonstrating its potential value for scenarios requiring frequent image guidance,such as adaptive radiotherapy.

Objective:To apply statistical process control (SPC) techniques to the quality assurance of non-normal radiotherapy plans through Johnson transformation, establishing patient-specific tolerance and action limits based on treatment sites and dose/distance assessment criteria, thereby enhancing the intensity-modulated radiation therapy (IMRT) verification accuracy and dose delivery precision.Methods:In this study, 951 gamma analysis data of patient-specific quality assurance (PSQA) executed on the Halcyon accelerator platform were selected and categorized into six groups based on treatment sites, including brain (102 cases), head and neck (100 cases), breast (229 cases), lung (154 cases), esophagus (223 cases), and pelvic (143 cases) groups. The six groups of data were statistically analyzed through Anderson-Darling normality tests ( α = 0.05) using Minitab 21 software. Non-normal data were transformed into normal data through Johnson transformation and then were used to establish treatment site-specific tolerance and action limits, which were compared with the Shewhart control charts based on normal distributions. Results:The PSQA result of the six groups all exhibited non-normal distributions ( P < 0.05). Through Johnson transformation, the tolerance and action limits for the head and neck, breast, lung, esophagus, and pelvic areas under the 3%/2 mm criterion ranged from 95.13% to 96.16% and 94.19% to 95.91%, respectively. In contrast, the tolerance and action limits ranged from 91.15% to 94.86% and 89.94% to 94.78% under the 2%/2 mm criterion. Directly applying Shewhart control charts without normality assumptions yielded higher tolerance limits compared to the application of Johnson transformation, increasing the false positive rate in the non-normal PSQA process. Conclusions:Applying the SPC techniques directly to a non-normal process can lead to an increased false alarm rate and wrong process interpretation. The SPC techniques combined with Johnson transformation enable more effective monitoring of a non-normal PSQA process, facilitating timely identification of potential factors that may lead to an out-of-control process based on the treatment site-specific limits.

Objective To propose and validate a decomposition method based on half-projection reconstruction for dual-energy cone beam CT(DE CBCT),thereby providing a potentially feasible low-dose imaging solution for anatomical monitoring and dose reconstruction optimization in adaptive radiotherapy.Methods Dual-energy scans were performed on a Gammex phantom using the on-board kilovoltage CBCT system of a VitalBeam accelerator at acquisition frame rates of 15 and 7 frames per second(f/s).Images were reconstructed from the projection data,and dual-energy decomposition was applied to the 7 f/s dual-energy images to derive relative electron density(RED)and stopping power ratio(SPR)using weighted formulas and empirical functions,followed by accuracy evaluation.Additionally,the weighted CT dose index was calculated for different scanning parameters.Results Dual-energy decomposition effectively suppressed image artifacts,with RED and SPR errors remaining below 2.82%and 2.56%,respectively.Compared with the traditional dual-scan method which required high-and low-energy acquisitions,the weighted CT dose index of the half-projection DE CBCT was reduced by 11.60 mGy(a 52.90%reduction).Furthermore,it was 2.58 mGy lower than the dose of the full-projection high-energy CBCT alone(a 19.98%reduction)and only 1.31 mGy higher than that of the low-energy CBCT(a 14.52%increase).Conclusion The proposed method effectively suppresses image artifacts while maintaining high accuracy in RED and SPR under low radiation dose conditions,demonstrating its potential value for scenarios requiring frequent image guidance,such as adaptive radiotherapy.

Objective:To apply statistical process control (SPC) techniques to the quality assurance of non-normal radiotherapy plans through Johnson transformation, establishing patient-specific tolerance and action limits based on treatment sites and dose/distance assessment criteria, thereby enhancing the intensity-modulated radiation therapy (IMRT) verification accuracy and dose delivery precision.Methods:In this study, 951 gamma analysis data of patient-specific quality assurance (PSQA) executed on the Halcyon accelerator platform were selected and categorized into six groups based on treatment sites, including brain (102 cases), head and neck (100 cases), breast (229 cases), lung (154 cases), esophagus (223 cases), and pelvic (143 cases) groups. The six groups of data were statistically analyzed through Anderson-Darling normality tests ( α = 0.05) using Minitab 21 software. Non-normal data were transformed into normal data through Johnson transformation and then were used to establish treatment site-specific tolerance and action limits, which were compared with the Shewhart control charts based on normal distributions. Results:The PSQA result of the six groups all exhibited non-normal distributions ( P < 0.05). Through Johnson transformation, the tolerance and action limits for the head and neck, breast, lung, esophagus, and pelvic areas under the 3%/2 mm criterion ranged from 95.13% to 96.16% and 94.19% to 95.91%, respectively. In contrast, the tolerance and action limits ranged from 91.15% to 94.86% and 89.94% to 94.78% under the 2%/2 mm criterion. Directly applying Shewhart control charts without normality assumptions yielded higher tolerance limits compared to the application of Johnson transformation, increasing the false positive rate in the non-normal PSQA process. Conclusions:Applying the SPC techniques directly to a non-normal process can lead to an increased false alarm rate and wrong process interpretation. The SPC techniques combined with Johnson transformation enable more effective monitoring of a non-normal PSQA process, facilitating timely identification of potential factors that may lead to an out-of-control process based on the treatment site-specific limits.

Objective:To study the risk factors of metabolic bone disease (MBD) associated fracture in very low birth weight premature infants.Methods:From January 2012 to December 2019, premature infants (gestational age <32 weeks, birth weight <1 500 g) were admitted to our hospital and followed-up regularly for 1.5 years (once every month within first 6 months, then once every 3 months). The infants were assigned into two groups according to X-ray diagnosis: the fracture group and the non-fracture group. The clinical data of the two groups were compared and the risk factors of fracture were analyzed.Results:A total of 62 preterm infants with MBD were included in this study, including 11 in the fracture group and 51 in the non-fracture group. The risk factors of MBD associated fracture included intrauterine growth restriction (IUGR), birth weight <1 000 g, gestational age, respiratory support duration and total parenteral nutrition (TPN) duration ( P<0.05). Logistic regression analysis showed that IUGR ( P<0.05, OR=2.159, 95% CI 1.536~2.759) and TPN duration ( P<0.05, OR=1.143, 95% CI 1.042~1.270) were independent risk factors for fracture. Serum alkaline phosphatase (ALP) in the fracture group was significantly higher than the non-fracture group and 25(OH)VitD was significantly lower than the non-fracture group ( P<0.05). Conclusions:IUGR and TPN duration are risk factors for MBD associated fracture in preterm infants. As biochemical markers of bone metabolism, ALP and 25(OH)VitD levels have clinical value predicting MBD associated fracture.

Objective:To synthesize Gd labeled probe targeting transporter protein(TSPO) 2-(8-amino-2-(4-chlorophenyl)imidazo[1, 2-a]pyridine-3-yl)- N, N-dipropylacetamide (CB86)-diethylene triamine pentaacetic acid (DTPA), and investigate its MRI effect in rheumatoid arthritis (RA) model. Methods:CB86-DTPA was prepared by coupling a bifunctional chelating agent, and then chelated with Gd to obtain MRI targeted contrast agent CB86-DTPA-Gd. The cytotoxicity, MR relaxation rate and in vitro stability of CB86-DTPA-Gd were determined. RA model was established with Freund′s adjuvant and the biodistribution study and MRI was performed. The RA lesion and its surrounding normal tissue were used as regions of interest (ROI) to calculate the signal to noise ratio (SNR). Independent-sample t test was used to analyze the data. Results:CB86-DTPA-Gd had excellent biosafety and a good MR relaxation rate ( r1=11.05 mmol·L -1·s -1). The survival rate of RAW264.7 cells and 4T1 cells was still more than 90% at the maximum concentration (20 μmol/L) of Gd 3+. CB86-DTPA-Gd also exhibited good stability in human serum and phosphate buffer saline solution (PBS; pH=7.4). The in vivo biodistribution showed that CB86-DTPA-Gd had better inflammatory targeting efficiency, and the uptake of Gd in the inflamed site of the ankle joint was still (2.33±0.29) percent dose rate per gram of tissue (%ID/g) at 120 min after injection. MicroMRI showed that the inflammation of the right ankle joint displayed significant enhancement after the injection of CB86-DTPA-Gd and Gd-DTPA. The SNR of CB86-DTPA-Gd group was up to 23.21±1.44, and the maximum intensification time was 90 min after injection, and can be significantly inhibited by CB86-DTPA at all time points ( t values: 6.083-12.451, all P<0.05), while the Gd-DTPA group had a strengthening time of 30 min after injection with the SNR of 16.12±1.24. Conclusion:CB86-DTPA-Gd shows good macrophage targeting and good uptake in arthritic reaction sites, and is expected to be a novel MRI molecular probe for peripheral inflammation imaging.

Objective:The aim of this study was to study the characteristics of neoplasm invasion type in ovary of two orthotopic models established with human epithelial ovarian cancer solid tumor tissue slices and human ovarian carcinoma cell line OVCAR-3 in nude mice and human epithelial ovarian cancer.Methods:Tumor tissues and cell line OVCAR-3 of human epithelial ovarian cancer were grown in subcutaneous tissue and the subcutaneous tumor source was fetched and inoculated in ovarian capsule of nude mice to establish the orthotopic implantation model. The neoplasm invasion type in the two kinds of models were observed. The neoplasm invasion types were also analyzed by pathological examination in 54 cases of International Federation of Gynecology and Obstetrics (FIGO) stageⅠ-Ⅱepithelial ovarian cancer.Results:Three neoplasm invasion types were found as follows: type of pseudocapsule, type of pseudocapsule invasion, type of pseudocapsule penetration. Pseudocapsule rate in the solid tumor slices group (18.2%) were lower than those in the cell line group (42.3%) ( P<0.05), while the pseudocapsule penetration rate in the solid tumor slices (50.0%) were higher than those in the cell line group (23.1%) ( P<0.05). No difference was found of pseudocapsule invasion rate between two groups ( P>0.05). Neoplasm invasion type in ovary changed with tumor planting time. High proportion of pseudocapsule type was found at the beginning of tumor planting, and the pseudocapsule penetration rate raised with tumor planting time increased. High proportion of pseudocapsule type was also found in patients with FIGO stageⅠepithelial ovarian cancer, and pseudocapsule penetration rate increased in those with FIGO stageⅡ. No difference in neoplasm invasion type was found between two kinds of pathological types ( P>0.05). Conclusions:There are differences between the two kinds of orthotopic models established with human epithelial ovarian cancer solid tumor tissue slices and human ovarian carcinoma cell line OVCAR-3. Compared to the solid tumor slices model, the cell line model is more stable for the follow-up study. The proportion of three neoplasm invasion types in ovary were more balanced in 8 weeks after tumor planting, and 8 weeks after tumor planting is the best start time for the follow-up experiment.

Objective To synthesize a novel 18 F labeled probe targeting translocator protein ( TSPO) ligand 2-( 5, 7-diethyl-2-( 4-( 2-fluoroethoxy ) phenyl ) pyrazolo [ 1, 5-a ] pyrimidin-3-yl )-N, N-diethylacet-amide (VUIIS1008), and evaluate its biodistribution and imaging in rheumatoid arthritis (RA) model. Methods The tosylate substrate was labeled with 18 F using a tosyloxy for fluorine nucleophilic aliphatic substitution to obtain 18 F-VUIIS1008. The labeling efficiency, radiochemical purity, and stability in vitro were determined. In vitro cellular uptake and competitive binding assay were performed on RAW264.7 mac-rophage cells. Biodistribution and microPET/CT imaging were investigated on RA mice established by Com-plete Freund's Adjuvant. Two-sample t test was used to analyze the data. Results 18 F-VUIIS1008 was syn-thesized with the labeling yield up to (41.00±5.00)％, the radiochemical purity>98.00％, and the specific radioactivity >1. 52 × 108 MBq/mmol. 18 F-VUIIS1008 was highly stable with the radiochemical purity >98. 00％ at 4 h after incubation in mouse serum. In vitro, it also exhibited high specific TSPO binding in RAW264.7 macrophage cells. The uptake ratio was (14.00±0.30)％ at 1 h after incubation, and decreased significantly ((4.00±0.70)％;t=12.894, P<0.05) after adding excessive unlabeled VUIIS1008. The half maximal inhibitory concentration (IC50) of 18F-VUIIS1008 binding to TSPO was 0.05 nmol/L in RAW264.7 macrophage cells. In vivo distribution results showed that the uptake of 18 F-VUIIS1008 in the left arthritic ankles reached the peak value of (1.33±0.02) percentage activity of injection dose per gram of tissue (％ID/g) at 1 h after injection. The radioactivity ratio of left ankle arthritic tissue to blood ( A/B) and to normal muscle ( A/M) was 4.40±0.22 and 1.65±0.07 respectively. MicroPET/CT imaging demonstrated that 18F-VUIIS1008 could specifically target and retained in the inflammation site. Conclusion 18 F-VUIIS1008 can be easily synthe-sized with high radiochemical purity and can clearly visualized in RA imaging with low background, suggesting its potential as a novel promising molecular probe targeting TSPO for RA PET imaging.

Objective To evaluate the efficacy and safety of 13-cis retinoid acid (13-CRA) and all trans retinoid acid (ATAR) redifferentiation therapy in patients with poorly differentiated thyroid cancer. Methods A single-center, randomized, double-blind, parallel controlled clinical trial was preformed. All patients were randomized into three groups. 78 cases were enrolled in each group. The patients were treated by 13-CRA in A group, by ATRA in B group, and by placebo in control group. The induced effects of retinoid acid (RA) and 131I treatment efficacies were defined as primary outcome of efficacy. Results After RA induction therapy, the effective rates in A, B, and control groups were 59.72%, 52.86% and 7.69%, respectively, with statistically significant difference among 3 groups (P<0.05). Compared with control group, A and B groups revealed significant induced efficacies (P<0.017), but there was no significant difference between A group and B group. After 131I treatment, the effective rates in A, B, and control group were 70.83%, 64.29%, and 28.21% respectively, with statistically significant difference (P<0.05). Compared with control group, the effective rates of 131I treatment in A and B groups were significantly raised (P<0.017), but there was no significant difference between A group and B group. The damage of skins and mucous membranes such as desquamation, dry skin, dry lips, dry eyes, etc occurred mostly in A group. The symptoms of nervous system such as headache, dizziness, etc occurred mostly in B group. Conclusions The induced differentiation of 13-CRA or ATRA is an effective method for the treatment of poorly differentiated thyroid carcinoma.

Aim To investigate the role of tryptophan hydroxylase-2 (TPH2),dopa-decarboxylase (DDC)and monoamine oxidase-A(MAO-A)in depression-like be-haviors induced by chronic unpredictable stress (CUS).Methods 30 male SD rats were randomly di-vided into model group(MG)and control group(CG). Rat depression model was developed by CUS for 28 consecutive days in a solitary condition.The depres-sion-like behaviors of rats were evaluated by open-field test(OFT)and forced-swimming test(FST).The real time PCR and Western blot test were used to determine the mRNA and protein expression of TPH2,DDC and MAO-A in rat telencephalon and hippocampus.Re-sults The movement scores of rats were obviously de-creased in OFT(P<0.01 ).The immobility time was obviously increased in FST (P <0.01 ).The mRNA and protein expressions of TPH2 and DDC were de-creased significantly (P <0.01,P <0.05 )and the MAO-A mRNA and protein expressions were increased significantly(P <0.01,P <0.05 )in telencephalon and hippocampus of MG rats, when compared with those in CG rats.Conclusion The TPH2,DDC and MAO-A in rat telencephalon and hippocampus were closely related with the depression-like behaviors of rats induced by CUS.