This paper aims to propose a noninvasive radiotherapy patient positioning system based on structured light surface imaging, and evaluate its clinical feasibility. First, structured light sensors were used to obtain the panoramic point clouds during radiotherapy positioning in real time. The fusion of different point clouds and coordinate transformation were realized based on optical calibration and pose estimation, and the body surface was segmented referring to the preset region of interest (ROI). Then, the global-local registration of cross-source point cloud was achieved based on algorithms such as random sample consensus (RANSAC) and iterative closest point (ICP), to calculate 6 degrees of freedom (DoF) positioning deviation and provide guidance for the correction of couch shifts. The evaluation of the system was carried out based on a rigid adult phantom and volunteers' body, which included positioning error, correlation analysis, and receiver operating characteristic (ROC) analysis. Using Cone Beam CT (CBCT) as the gold standard, the maximum translation and rotation errors of this system were (1.5 ± 0.9) mm along Vrt direction (chest) and (0.7 ± 0.3) ° along Pitch direction (head and neck). The Pearson correlation coefficient between results of system outputs and CBCT verification distributed in an interval of [0.80, 0.84]. Results of ROC analysis showed that the translational and rotational AUC values were 0.82 and 0.85, respectively. In the 4D freedom accuracy test on the human body of volunteers, the maximum translation and rotation errors were (2.6 ± 1.1) mm (Vrt direction, chest and abdomen) and (0.8 ± 0.4)° (Rtn direction, chest and abdomen) respectively. In summary, the positioning system based on structured light body surface imaging proposed in this article can ensure positioning accuracy without surface markers and additional doses, and is feasible for clinical application.
Humans ; Patient Positioning/methods* ; Phantoms, Imaging ; Cone-Beam Computed Tomography ; Algorithms ; Radiotherapy, Image-Guided/methods* ; Radiotherapy Planning, Computer-Assisted/methods*

To address the issues of difficulty in preserving anatomical structures, low realism of generated images, and loss of high-frequency image information in medical image cross-modal translation, this paper proposes a medical image cross-modal translation method based on diffusion generative adversarial networks. First, an unsupervised translation module is used to convert magnetic resonance imaging (MRI) into pseudo-computed tomography (CT) images. Subsequently, a nonlinear frequency decomposition module is used to extract high-frequency CT images. Finally, the pseudo-CT image is input into the forward process, while the high-frequency CT image as a conditional input is used to guide the reverse process to generate the final CT image. The proposed model is evaluated on the SynthRAD2023 dataset, which is used for CT image generation for radiotherapy planning. The generated brain CT images achieve a Fréchet Inception Distance (FID) score of 33.159 7, a structure similarity index measure (SSIM) of 89.84%, a peak signal-to-noise ratio (PSNR) of 35.596 5 dB, and a mean squared error (MSE) of 17.873 9. The generated pelvic CT images yield an FID score of 33.951 6, a structural similarity index of 91.30%, a PSNR of 34.870 7 dB, and an MSE of 17.465 8. Experimental results show that the proposed model generates highly realistic CT images while preserving anatomical accuracy as much as possible. The transformed CT images can be effectively used in radiotherapy planning, further enhancing diagnostic efficiency.
Humans ; Tomography, X-Ray Computed/methods* ; Magnetic Resonance Imaging/methods* ; Image Processing, Computer-Assisted/methods* ; Neural Networks, Computer ; Brain/diagnostic imaging* ; Algorithms ; Radiotherapy Planning, Computer-Assisted ; Generative Adversarial Networks

The standard treatment for locally advanced esophageal squamous cell carcinoma (ESCC) is neoadjuvant chemoradiotherapy, followed by surgery or definitive radiotherapy, but clinical results are unsatisfactory. In recent years, relevant studies have shown that immunotherapy combined with chemoradiotherapy has become a new treatment option for locally advanced ESCC. This article summarizes the current progress of chemoradiotherapy combined with immunotherapy in the treatment of locally advanced ESCC, and provides necessary theoretical basis for the comprehensive understanding and optimization of chemoradiotherapy combined with immunotherapy regimens for ESCC.
Humans ; Esophageal Squamous Cell Carcinoma/therapy* ; Esophageal Neoplasms/radiotherapy* ; Immunotherapy/methods* ; Chemoradiotherapy/methods* ; Combined Modality Therapy

Small cell lung cancer (SCLC) is the thoracic malignant tumor and accounts for about 15% of lung malignancies and transfer often occurs by the time of diagnosis. Extensive stage-small cell lung cancer (ES-SCLC) accounts for about 2/3 of all SCLC. For many years, radiotherapy has occupied an important position in the treatment of SCLC, especially in the treatment of ES-SCLC, because SCLC is more sensitive to radiotherapy. However, in recent years, immune checkpoint inhibitor has shown more excellent antitumor activity in the treatment of ES-SCLC and become the mainstream argument for the treatment of ES-SCLC. However, will radiotherapy be buried by the times among the therapeutic approaches for ES-SCLC? In this article, we will review the clinical progress of radiotherapy, immunotherapy and combination therapy for ES-SCLC.
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Humans ; Small Cell Lung Carcinoma/therapy* ; Lung Neoplasms/therapy* ; Immunotherapy ; Neoplasm Staging ; Radiotherapy/methods* ; Combined Modality Therapy

Tianhe procedure^® is a functional sphincter-preserving surgical approach developed for rectal cancer patients following radiotherapy. This technique involves extended proximal resection of the colon beyond the pelvic cavity, followed by anastomosis of the non-irradiated proximal colon to the distal rectum or anal canal. This strategy aims to reduce the incidence of anastomotic complications and postoperative bowel dysfunction. However, there is currently a lack of standardized practice guideline for implementing Tianhe procedure^® in China. Therefore, the Chinese Radiation Intestinal Injury Research Group, the Colorectal Surgery Group of Surgery Branch of the Chinese Medical Association, the Anorectal Branch of Chinese Medical Doctor Association, the Colorectal Cancer Committee of the Chinese Medical Doctor Association, and the Colorectal Cancer Committee of China Anti-cancer Association, and the Gastrointestinal Surgical Branch of Guangdong Medical Doctor Association, have jointly convened a panel of national experts to discuss and establish this standardized surgical procedure. This standard, based on the latest evidence from literature, research advancements, and expert experience, focuses on key aspects of the Tianhe procedure^®, including its precise definition, indications, critical procedural steps, postoperative complications, and functional rehabilitation strategies. It aims to promote standardized implementation and broader clinical adoption of this innovative surgical technique.
Humans ; Rectal Neoplasms/radiotherapy* ; Anal Canal/surgery* ; Anastomosis, Surgical/methods* ; Organ Sparing Treatments/methods* ; Rectum/surgery* ; Postoperative Complications/prevention & control* ; Digestive System Surgical Procedures/methods*

OBJECTIVE: Automatic planning is a commonly used alternative to manual planning. This study evaluated the clinical performance of automatic plans available in commercial treatment planning systems for nasopharyngeal carcinoma (NPC) treatment by comparing automatic planning with manual planning. METHODS: A total of 14 patients with nasopharyngeal carcinoma were enrolled in the study. For each patient, three different sets of clinical goals were used to generate three hybrid automatic plans based on 3D dose distribution prediction and three automatic plans based on script, respectively, which were compared with the manual plans used in clinic. RESULTS: The dose coverage performance of the automatic planning based on 3D dose distribution prediction on the planning target volume (PTV) was comparable to that of the manual planning. Automatic planning based on 3D dose prediction achieved the level of manual planning in most organs at risk. However, automatic planning based on scripts did not perform well in the prediction of some organs at risk, especially the parotid gland. CONCLUSION The hybrid automatic plan based on 3D dose distribution prediction can reach the level of manual planning and have good robustness with the change of clinical objective.
Humans ; Nasopharyngeal Neoplasms/radiotherapy* ; Radiotherapy Planning, Computer-Assisted/methods* ; Nasopharyngeal Carcinoma ; Male ; Female ; Middle Aged ; Adult ; Carcinoma ; Radiotherapy Dosage

OBJECTIVE: To analyze the time characteristics of the Ethos online adaptive radiotherapy (OART) process in clinical practice and provide guidance for the comprehensive optimization of each stage of adaptive radiotherapy. METHODS: The study involved 61 patients with cervical, rectal, gastric, lung, esophageal, and breast cancers who underwent Ethos OART. The mean ± standard deviation of segmental time, total time, and target volume for these patients were tracked. The time characteristics for different cancer types were evaluated, and the average time for target and organ at risk (OAR) modifications was compared with the average target volume for each cancer type. RESULTS: Cervical cancer born the longest total treatment time, while breast cancer had the shortest. For all cancer types except breast cancer, the modification time for target and OAR was the most time-consuming segment. The average time for target and OAR modifications aligned with the trend of the average target volume. CONCLUSION The total treatment time for various cancers ranges from 15 to 35 minutes, indicating room for improvement.
Humans ; Radiotherapy Planning, Computer-Assisted/methods* ; Neoplasms/radiotherapy* ; Female

3D printing technology, with a layer-by-layer construction method, enables the fabrication of intricately shaped and customizable bolus. In contrast to traditional preparation methods, 3D printing technology addresses challenges such as poor bolus fit and cumbersome production processes, offering a novel approach to efficient and personalized bolus fabrication. This article discusses the research progress of 3D printing technology in radiotherapy bolus from aspects such as the preparation process, clinical application, and research advancements, combined with the actual printing experience of Department of Radiation Oncology in Chongqing University Cancer Hospital.
Printing, Three-Dimensional ; Humans ; Radiotherapy/methods*

OBJECTIVE: To study effective methods for reducing lung V₅, V₁₀, and mean lung dose (MLD) in the design of volumetric modulated arc therapy for central lung cancer by using different arc configurations and dose-limiting blocks designs. METHODS: Five groups of plans were designed for the enrolled patients. Group A used a full-arc field. Group B used a partial-arc field. Groups C, D, and E used full-arc fields with vertical-length, semi-ring, and triangular dose-limiting blocks added respectively. The dosimetric similarities of target areas and the dosimetric differences in lung V₅, V₁₀, V₂₀, and MLD among the groups were compared. RESULTS: Compared with group A, groups B, C, D, and E had decreased homogeneity and conformity of the target area, but significantly lower V₅ and V₁₀ of the whole lung. The MLD of groups C, D, and E was lower than that of group A. CONCLUSION Using a full-arc field combined with dose-limiting blocks can effectively reduce lung V₅, V₁₀, MLD, and monitor units (MU).
Lung Neoplasms/radiotherapy* ; Humans ; Radiotherapy, Intensity-Modulated/methods* ; Radiotherapy Planning, Computer-Assisted/methods* ; Radiotherapy Dosage ; Lung/radiation effects*

OBJECTIVE: To evaluate the feasibility and accuracy of cone-beam CT (CBCT) images for radiotherapy dose calculation in pelvic tumors. METHODS: An improved volumetric density coverage method was used to establish CT value-relative electron density (RED) curves for CBCT images. The planning CT plans were transferred to the CBCT images, and the constructed density curves were applied to calculate doses for CBCT plans while maintaining the optimization parameters unchanged. Dose calculation deviations between the two plans were analyzed. RESULTS: The mean differences in dosimetric parameters for the target volume and organs at risk (OAR) between the two plans were less than 1% and 1.5%, respectively. The target conformity index (CI), homogeneity index (HI), and gamma passing rates were highly consistent, with no statistically significant differences. CONCLUSION CBCT images corrected by this method can be used for dose calculation in pelvic tumor radiotherapy planning.
Cone-Beam Computed Tomography/methods* ; Humans ; Radiotherapy Planning, Computer-Assisted/methods* ; Radiotherapy Dosage ; Pelvic Neoplasms/diagnostic imaging*