Feng Chi

To compare the incidence of radiation-induced temporal lobe injury (TLI) between helical tomotherapy (HT) and conventional intensity-modulated radiotherapy

This study aimed to investigate the progression of taste dysfunction (TD) in patients with head and neck cancer (HNC) receiving radiotherapy (RT) and to de

Background: This retrospective cohort study aims to study the changes of the exposed volume of the bladder and rectum under different filling states, and to clarify the influences of the morphing organs on themselves and each other, to provide the basis for reducing the risk of organ damage by intensity-modulated radiotherapy (IMRT) for cervical cancer. Methods: A retrospective analysis was performed on 24 patients with cervical cancer who received IMRT. Before radiotherapy, a comfortably full bladder and active defecation was ensured for all patients, and interative cone-beam computed tomography (iCBCT) was performed to delineate the bladder, rectum, and small intestine. The filling degree of the bladder, rectum, and small intestine and their intersection with the planned target volume were recorded. Results: 83.44% of patients exhibited reduced bladder volume during treatment. When the planned bladder volume was 400–500 cc, the bladder volume changed the least during treatment (F = 58.39, P < .001). The exposed volume of the small intestine was moderately correlated with the degree of bladder filling ( r = −.674, P < .01). For every 10% increase in bladder volume, the exposed volume of the small intestine decreased by 24.05% ( P < .01). Furthermore, 45.83% patients had an increase in rectum volume during treatment. The exposed volume increased by 9.47% for every 10% increase in rectum volume ( P < .01). Conclusion: Comfortable bladder and active defecation regimens may not keep bladder and rectal stability. Targeting a planned bladder volume of 400 to 500cc minimizes intrafraction variability. Strategic bladder filling optimization may mitigate small intestine exposure.

Objective: The objective of this study is to evaluate the impact of different belly board and daily changes in patient's body‐mass factor (BMF) on setup displacement in radiotherapy for rectal cancer.Methods: Twenty‐five patients were immobilized using the thermoplastic mask with belly board (TM‐BB), and 30 used the vacuum bag cushion with belly board (VBC‐BB), performing daily cone‐beam computed tomography (CBCT) scans 625 times and 750 times, respectively. Daily pretreatment CBCT scans were registered to the planned CT images for BMF change determination and setup displacement measurement. Independent t‐tests compared setup displacement between the two groups in left‐right (LR), superior‐inferior (SI), and anterior‐posterior (AP) directions, as well as the BMF changes. The impact of daily BMF changes on setup displacement was evaluated using multivariate logistic regression and 10‐fold cross‐validation.Results: The setup displacement for TM‐BB in the LR, SI, and AP directions were 0.31 ± 0.25, 0.58 ± 0.40, and 0.19 ± 0.18 cm, respectively, while VBC‐BB showed 0.19 ± 0.15, 0.26 ± 0.22, and 0.36 ± 0.29 cm in the corresponding directions, respectively. Margins of planning target volume (PTV) for TM‐BB were 8, 10, and 6 mm in LR, SI, and AP directions, while VBC‐BB showed margins of 5,7, and 8 mm, respectively. The daily BMF changes for both groups were ranked in descending order as follows: sacral rotation angle (RS), hip lateral diameter (HLD), and hip anterior‐posterior diameter (HAPD). HAPD was the main factor affecting setup displacement in both the AP and SI directions in TM‐BB, while RS was the primary factor for setup displacement in the AP direction in VBC‐BB.Conclusion: Compared with TM‐BB, VBC‐BB had a larger AP displacement but smaller in LR and SI displacement. Daily changes in BMF have distinct effects on setup displacement in different immobilization devices. Image‐guided radiation therapy (IGRT) is highly recommended and BMF changes should be given consideration during radiotherapy.

Objective. The aim of this study was to reconstruct volumetric computed tomography (CT) images in real-time from ultra-sparse two-dimensional x-ray projections, facilitating easier navigation and positioning during image-guided radiation therapy. Approach. Our approach leverages a voxel-sapce-searching Transformer model to overcome the limitations of conventional CT reconstruction techniques, which require extensive x-ray projections and lead to high radiation doses and equipment constraints. Main results. The proposed XTransCT algorithm demonstrated superior performance in terms of image quality, structural accuracy, and generalizability across different datasets, including a hospital set of 50 patients, the large-scale public LIDC-IDRI dataset, and the LNDb dataset for cross-validation. Notably, the algorithm achieved an approximately 300% improvement in reconstruction speed, with a rate of 44 ms per 3D image reconstruction compared to former 3D convolution-based methods. Significance. The XTransCT architecture has the potential to impact clinical practice by providing high-quality CT images faster and with substantially reduced radiation exposure for patients. The model's generalizability suggests it has the potential applicable in various healthcare settings.