The results indicate that proinflammatory type 1 genes regulated by IFN-gamma are similarly increased in both SP and LP psoriasis, but a potential difference in IL-18 exists between these disease forms. The consistent activation of this set of genes argues for a central role of IFN-gamma as a molecular regulator of inflammation in these distinct subtypes of psoriasis vulgaris. In contrast, disease extent/severity must be controlled by yet other factors.

Purpose: To investigate the ability of CyberKnife to track surgical clips used as fiducial markers. Methods: The Octavius 1000SRS detector and solid water (RW3) slab phantom were used with motion platform to evaluate the study. The RW3 slab phantom was set up to measure the dose distribution from coronal plane. It consists of 9 plates and the thickness of each plate is 10mm. Among them, one plate was attached with 3 surgical clips, which are orthogonally positioned on outer region of array. The length of attached clip was represented as 1cm on planning CT. The clip plate was placed on the 1000SRS detector and 3 slabs were stacked up on the plate to build the measuring depth. Below the detector, 5 slabs were set. The two‐axis motion platform was programmed with 1D sinusoidal movement (20mm peak‐to‐peak, 3s period) toward superior/inferior and left/right directions to simulate target motion. During delivery, two clips were extracted by two X‐ray imagers, which led to translational error correction only. Synchrony was also used for dynamic tracking. After the irradiation, the measured dose distribution of coronal plane was compared with the planar dose distribution calculated by the CyberKnife treatment planning system (Multiplan) for cross verification. The results were assessed by comparing the absolute Gamma (γ) index. Results: The dose distributions measured by the 1000SRS detector were in good agreements with those calculated by Multiplan. In the dosimetric comparison using γ‐function criteria based on the distance‐to‐agreement of 3mm and the local dose difference of 3%, the passing rate with γ‐ parameter ≤1 was 91% in coronal plane. Conclusion: The surgical clips can be considered as new fiducials for robotic radiosurgery delivery by considering the target margin with less than 5mm.

Purpose: To develop an iterative reconstruction algorithm using a compressed sensing with adaptive prior image constraints to solve 4D CBCT reconstruction problem. Methods: The images reconstructed by the FDK algorithm with a full set of unsorted projections are served as prior images for partial projections in each phase group and are utilized as an initial guess. Additionally, the prior images are clustered into several regions by applying intensity‐based thresholding, which is referred to as the segmented prior images. The segmented prior images are employed to detect any possible mismatched areas compared with the target images generated by partial projection data. With these two prior images, our algorithm alternately performs the simultaneous algebraic reconstruction technique and anisotropic total variation regularization while adjusting a weighted relaxation map during the iterative reconstruction process. The weighted relaxation map depends on binary images created by the voxel‐dependent comparison between the segmented prior and segmented target images. For the segmented target images, the k‐means clustering with a geometric weighting is applied on the reconstruction images generated in each iteration step. The inverse values of the distance map converted from binary images are assigned to be the values of the relaxation map. Evaluations using Catphan504 phantom with a motion platform were carried out. Results: Qualitative and quantitative analyses showed that the method provides high‐quality CBCT reconstruction images when compared with those generated by the FDK, CS, and PICCS algorithms, with higher contrast‐to‐noise ratio and faster convergence caused by minimizing data fidelity. Especially, the proposed method was superior to PICCS in the aspect of updating locally‐mismatched region. Conclusion: The proposed method not only improves the image quality of 4D CBCT by adaptive updates during the reconstruction process, but also leads to a lower imaging dose and faster acquisition time by using a regular 3D CBCT scan.