e16457 Background: Significant anatomical variations of organs-at-risk (OARs), particularly the stomach and duodenum, pose major challenges in abdominal radiotherapy. This study aimed to quantitatively characterize the interfractional geometric stability of these organs during a standard treatment course to provide a scientific basis for adaptive planning and margin optimization. Methods: We retrospectively analyzed 10 patients with abdominal cancer who received radiotherapy. For each patient, diagnostic-quality kV-level fan-beam CT (kV-FBCT) scans were performed daily before each treatment fraction using an integrated linac system (uRT-linac 506). A total of 110 serial scans—including the initial planning CT (pCT) and 10 repeat scans per patient sampled during the treatment course—were retrieved. The stomach and duodenum were manually re-contoured on all scans by senior radiation oncologists. Geometric variations were evaluated using: 1) Volumetric change (ΔV%); 2) Surface-based agreement (MDA and HD); 3) Spatial overlap assessment (DSC). Results: A total of 110 daily kV-FBCT scans were evaluated. The stomach exhibited profound geometric instability, with a mean DSC of 0.62 ± 0.11 and extreme volumetric expansion up to 299.81% (mean ΔV%: 45.08% ± 60.66%). The mean MDA and HD for the stomach were 6.18 ± 3.17 mm and 26.55 ± 12.41 mm, respectively. The duodenum showed even poorer spatial overlap (mean DSC: 0.52 ± 0.12). These geometric variations remained unpredictable and significant throughout the treatment course, with no trend of anatomical stabilization observed. Conclusions: During abdominal radiotherapy, the stomach and duodenum undergo substantial and unpredictable interfractional shifts. The low DSC values and large Hausdorff distances observed via daily kV-FBCT suggest that static planning margins are insufficient. Our quantitative data underscore the necessity of online anatomical assessment and adaptive strategies to ensure safe treatment delivery near gastrointestinal structures.

e16270 Background: Lattice spatially fractionated radiotherapy (Lattice SFRT) creates highly heterogeneous “peak-and-valley” dose distributions within tumors, offering a novel approach for bulky hepatocellular carcinoma (HCC) where conventional radiotherapy is often limited. This study retrospectively evaluated the safety and preliminary efficacy of Lattice SFRT combined with concurrent systemic therapy in patients with bulky, unresectable HCC. Methods: Patients with bulky, unresectable HCC who received Lattice SFRT between March 1, 2023, and July 31, 2025, were retrospectively enrolled. All treatments were delivered at a frequency of five fractions per week consecutively. Using volumetric modulated arc therapy (VMAT), the prescribed doses were set as follows: the lattice vertices within the gross tumor volume (GTV) received 35 Gy in 5 fractions, while the entire GTV simultaneously received a lower dose of 10 Gy in 5 fractions, thus constructing a specific intratumoral dose distribution. The treatment regimen was individualized, with 10 patients receiving 2 courses and 3 patients receiving 3 courses of Lattice SFRT. The primary endpoints were objective response rate (ORR) and the incidence of treatment-related adverse events (TRAEs). Secondary endpoints included local control (LC), progression-free survival (PFS), and overall survival (OS). Results: A total of 32 patients were analyzed, of whom 71.9% (n = 23) had tumors with a maximum diameter ≥10 cm. All patients received Lattice SFRT combined with concurrent systemic therapy. After a median follow-up of 9.1 months, the ORR was 53.1%, and local control was maintained in all irradiated lesions. No significant differences were observed in LC (median 11.1 vs. 7.7 months, P = 0.537) or PFS (median 11.1 vs. 7.7 months, P = 0.268) between responders and non-responders. However, responders achieved a significantly longer OS (median not reached vs. 12.3 months, P = 0.005). No grade ≥3 treatment-related hepatic toxicity or unmanageable TRAEs occurred. Hepatic functional reserve remained stable overall after treatment, with improvement in Child-Pugh class observed in four patients (12.5%). Conclusions: For patients with bulky, unresectable HCC, an individualized, multi-course Lattice SFRT regimen employing a “whole-tumor low-dose (10 Gy/5 fx) combined with intratumoral vertex high-dose (35 Gy/5 fx)” strategy demonstrated favorable local control and survival benefit with an acceptable safety profile. These findings support its potential as a promising locoregional treatment option for this challenging patient population, warranting further validation in prospective studies.

Precise spatial distribution of interstitial needles is critical for 3D-printing-assisted brachytherapy in cervical cancer. This study proposes a greedy algorithm-based needle trajectory planning (GANTP) framework to generate patient-specific needle configurations while ensuring needle collision avoidance and achieving clinically acceptable high-risk clinical target volume (HR-CTV) coverage in compliance with OAR dose constraints. The GANTP framework comprises three core steps: (1) Generation of candidate trajectories anchored within clinically viable entry zones; (2) Parameter-driven greedy selection of needle trajectories based on a geometric influence radius (δ) evaluated at three discrete values (12, 15, and 18 mm), where δ serves as a geometric surrogate for dose coverage, together with a geometric coverage-ratio threshold (γ = 98

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.

Purpose. This study aims to synthesize CT from MR images for radiotherapy planning of head and neck tumor using an improved three-dimensional conditional generative adversarial network (3D cGAN) based on dual-attention modules.Methods. A total of 212 paired CT and T1-weighted MRI datasets are utilized, including 180 publicly available cases and 32 clinical cases from our hospital. Building upon the 3D cGAN framework, we implement structural modifications to the generator, discriminator, and loss functions. In particular, a lightweight dual-attention mechanism module is introduced to the generator based on 3D residual network. The model is trained on 186 datasets and evaluated on 26 test cases. Quantitative metrics including normalized cross-correlation (NCC), structural similarity index measure (SSIM), peak signal-to-noise ratio (PSNR), and mean absolute error (MAE) are calculated to assess the similarity between synthetic CT (sCT) and ground-truth CT images. A comparative analysis with U-Net, CycleGAN and basic 3D cGAN is conducted to validate performance improvements.Results. The proposed dual-attention enhanced 3D cGAN generates clinically acceptable sCT images across all 26 test cases. Quantitative evaluations demonstrate high accuracy with NCC of 97.06%, SSIM of 90.24%, PSNR of 28.23 ± 0.42, and MAE of 32.53 ± 2.49 HU. In quantitative comparison, the proposed dual-attention enhanced 3D cGAN approach outperforms U-Net, CycleGAN and the basic 3D cGAN across all metrics.Conclusion. This study proposes an improved dual-attention enhanced 3D cGAN algorithm. The method can rapidly and automatically generate sCT images from MR images for patients of head and neck tumor, which holds significant importance for implementing MR-only radiotherapy planning.

Background and purposeOne of the current roadblocks to the widespread use of Total Marrow Irradiation (TMI) and Total Marrow and Lymphoid Irradiation (TMLI) is the challenging difficulties in tumor target contouring workflow. This study aims to develop a hybrid neural network model that promotes accurate, automatic, and rapid segmentation of multi-class clinical target volumes.Materials and methodsPatients who underwent TMI and TMLI from January 2018 to May 2022 were included. Two independent oncologists manually contoured eight target volumes for patients on CT images. A novel Dual-Encoder Alignment Network (DEA-Net) was developed and trained using 46 patients from one internal institution and independently evaluated on a total of 39 internal and external patients. Performance was evaluated on accuracy metrics and delineation time.ResultsThe DEA-Net achieved a mean dice similarity coefficient of 90.1 % ± 1.8 % for internal testing dataset (23 patients) and 91.1 % ± 2.5 % for external testing dataset (16 patients). The 95 % Hausdorff distance and average symmetric surface distance were 2.04 ± 0.62 mm and 0.57 ± 0.11 mm for internal testing dataset, and 2.17 ± 0.68 mm, and 0.57 ± 0.20 mm for external testing dataset, respectively, outperforming most of existing state-of-the-art methods. In addition, the automatic segmentation workflow reduced delineation time by 98 % compared to the conventional manual contouring process (mean 173 ± 29 s vs. 12168 ± 1690 s; P < 0.001). Ablation study validate the effectiveness of hybrid structures.ConclusionThe proposed deep learning framework achieved comparable or superior target volume delineation accuracy, significantly accelerating the radiotherapy planning process.

Stereotactic radiation therapy (SBRT) has emerged as a promising treatment modality for locally advanced pancreatic cancer. The aim of this study is to assess the dosimetric efficacy of online adaptive radiotherapy (ART) in comparison to image-guided radiation therapy (IGRT) for pancreatic cancer. We conducted a retrospective analysis involving 8 patients diagnosed with locally advanced pancreatic cancer. The gross tumor volume (GTV) delineates the visible extent of the tumor on imaging, while the planning tumor volume (PTV) was generated by expanding 5 mm from the GTV and ensuring a 3 mm distance from the small intestine, duodenum, and stomach simultaneously. Treatment planning was executed using the United Imaging Healthcare Treatment Planning System workstation. The control group underwent evaluation based on daily validated fan-beam CT (FBCT) scans, assessing both the dose delivered to actual organs at risk (OARs) and the target volume. Radiotherapy plans were developed utilizing simulation CT, and conventional radiotherapy with daily image-guided radiation therapy (IGRT) was administered using FBCT-Linac. Conversely, patients in the study group received daily validated FBCT-guided adaptive radiotherapy plans, with a focus on mean dose assessment of both the target volume and OARs. Subsequently, we compared the average outcomes of each treatment fraction between IGRT and online adaptive radiotherapy (ART). Comparison between ART and IGRT treatment plans revealed significant differences in various dosimetric parameters: For PTV: V98%: ART (96.28%) vs IGRT (89.73%), p = 0.000, V95%: ART (96.28%) vs IGRT (89.73%), p = 0.031, V90%: ART (98.58%) vs IGRT (93.65%), p = 0.000, Dmean: ART (4912.91) vs IGRT (4804.11), p = 0.000. For GTV: V100%: ART (97.96%) vs IGRT (94.85%), p = 0.314, V98%: ART (100.00%) vs IGRT (96.83%), p = 0.000, V90%: ART (100.00%) vs IGRT (97.75%), p = 0.000, Dmean: ART (4972.17) vs IGRT (4907.23), p = 0.000. For the duodenum: D0.5cc: ART (2883.92) vs IGRT (3359.35), p = 0.000, D1cc: ART (2726.32) vs IGRT (3128.66), p = 0.001, D5cc: ART (2051.96) vs IGRT (2273.93), p = 0.015, D10cc: ART (1650.73) vs IGRT (1731.74), p = 0.211. For the small bowel: D0.5cc: ART (3022.3) vs IGRT (3142.64), p = 0.037. D5cc: ART (2151.09) vs IGRT (2389.15), p = 0.043, D10cc: ART (1775.20) vs IGRT (1942.00), p = 0.079. For the stomach: D0.5cc: ART (3353.92) vs IGRT (4117.85), p = 0.000, D5cc: ART (2860.20) vs IGRT (3235.41), p = 0.000, D10cc: ART (2553.72) vs IGRT (2836.73), p = 0.000. For the Dmean of the left kidney and right kidney: Left kidney: ART (248.28) vs IGRT (239.65), p = 0.100. Right kidney: ART (314.55) vs IGRT (307.17), p = 0.345. These results suggest significant improvements in PTV coverage and sparing of OARs with ART compared to IGRT, indicating the potential of ART in optimizing treatment outcomes for pancreatic cancer patients. Compared to conventional IGRT-guided SBRT programs, ART-based SBRT for pancreatic cancer not only enhances the dose distribution to the target volume but also mitigates the radiation exposure to critical organs-at-risk (OARs) such as the duodenum, small intestine, and stomach. This approach may offer a more favorable safety profile while concurrently enhancing treatment efficacy.

This case report details the treatment process and outcomes of an elderly patient with locally advanced pancreatic cancer (LAPC) managed with online adaptive radiotherapy (ART) guided by fan-beam computed tomography. The patient exhibited significant tumor regression (partial response) during the treatment course. Follow-up imaging one year after treatment confirmed sustained tumor remission and maintained a good quality of life. These findings highlight the potential efficacy of online ART in the management of LAPC.

PurposeTo assess the dosimetric effectiveness of image-guided radiation treatment (IGRT) and online adaptive radiation therapy (oART) for cervical cancer. As well as survival follow-up was conducted to validated the safety and efficacy of oART.MethodsA total of 15 cervical cancer patients were enrolled. oART was performed on a CT-integrated linear accelerator. The initial plan was revised to include the distribution of IGRT dose using daily fan-beam CT (FBCT) images, after which the distinctions between ART and IGRT in terms of target coverage and organs at risk (OARs) sparing were analyzed. Survival follow-up was conducted to validated the safety and efficacy of oART in this group.ResultsPTV Dmax value decreased by 1.23 Gy in the ART plan when compared to that in the IGRT plan; PTV D95 increased by 1.34 Gy; PTV V50 coverage increased by 4.86%; CTV coverage increased by 3.02%; PTV D2cc of the colon, rectum, and small intestine decreased by 1.24 Gy, 1.29 Gy, and 1.12 Gy, respectively. The V10 and V30 of the pelvis increased by 1.27% and 0.56%, respectively, while the V30 of the left and right femoral heads dropped by 2.82% and 3.41%, respectively. Except for the pelvic changes, all other differences were statistically significant (p < 0.01). The average time for the ART procedure was 21.22 min (range: 18.72–24.90 min). The median follow-up time is 28.0 months. Median event-free survival and overall survival were not reached. EFS rate and OS rate at 3 years were 79.4% and 92.9%.ConclusionOnline ART for cervical cancer can minimize the dose of OARs and enhance the target volume coverage significantly when compared to IGRT with satisfied survival time.

BACKGROUND AND PURPOSE:3D-printed templates are used in intracavitary/interstitial brachytherapy (3DP-IC/IS) for locally advanced cervical cancer (LACC). We applied failure mode and effects analysis (FMEA) twice in one year to improve 3DP-IC/IS safety. MATERIALS AND METHODS:A risk assessment group was established. We created a process map for 3DP-IC/IS procedures, identifying potential failure modes (FMs) and evaluating occurrence (O), detectability (D), severity (S), and risk priority number (RPN = O*D*S). High RPN values identified high-risk FMs, and quality control (QC) methods were determined by root cause analysis. A second FMEA was performed a year later. RESULTS:The 3DP-IC/IS process included 10 main steps, 48 subprocesses, and 54 FMs. Initial RPN values ranged from 4.50 to 171.00 (median 50.50; average 52.18). Ten high-risk FMs were identified: (1) unreasonable needle track design (171.00/85.50), (2) noncoplanar needle label identification failure (126.00/64.00), (3) template model reconstruction failure (121.50/62.50), (4) improper gauze filling (112.00/60.25), (5) poor needle position (112.00/52.50). QC interventions lowered all high-risk RPN values during the second assessment. CONCLUSIONS:A feasible 3DP-IC/IS process was proposed. Staff training, automatic needle path planning, insertion guidance diagrams, template checking, system commissioning, and template design improvements effectively enhanced process safety.

目的 验证最新国产联影uRT-linac 506c医用直线加速器的剂量输出水平和稳定性.方法 对我院联影uRT-linac 506c医用直线加速器与瓦里安IX5570医用直线加速器进行每日质控,采集标准测试条件下的绝对剂量,并采集剂量输出的平坦度和对称性,分析两种直线加速器剂量输出稳定性.结果 联影uRT-linac 506c和瓦里安IX5570两种加速器6 MV能量的绝对剂量分别为(100.33±0.267)、(99.54±0.460)MU,剂量输出均符合正态分布.对于10cm×10cm辐射野的平坦度和对称性,联影uRT-linac 506c加速器和瓦里安IX5570加速器K-S检验为非正态分布,两种加速器平坦度平均在105％左右,整体分布均优于法规要求的106％;对称性平均分布在101％左右,整体分布均优于法规要求的103％.GT和LR方向平坦度和对称性测量误差均在0.5％以内.结论 考虑到测量过程、摆位以及测量工具等带来的误差,联影uRT-linac 506c加速器与瓦里安IX5570绝对剂量、平坦度、对称性和稳定性基本在同一水平,即国产联影uRT-linac 506c直线加速器具有较高的稳定性.

BackgroundA novel CT-linac (kilovolt fan-beam CT-linac) has been introduced into total marrow and lymphoid irradiation (TMLI) treatment. Its integrated kilovolt fan-beam CT (kV FBCT) can be used not only for image guidance (IGRT) but also to re-calculate the dose.PurposeThis study reported our clinical routine on performing TMIL treatment on the CT-linac, as well as dose distribution comparison between planned and re-calculated based on IGRT FBCT image sets.Methods11 sets of data from 5 male and 6 female patients who had underwent the TMLI treatment with uRT-linac 506c were selected for this study. The planning target volumes consist of all skeletal bones exclusion of the mandible and lymphatic sanctuary sites. A planned dose of 10 Gy was prescribed to all skeletal bones exclusion of the mandible in two fractions and 12 Gy in two fractions was prescribed to lymphatic sanctuary sites. Each TMLI plan contained two sub-plans, one dynamic IMRT for the upper body and the other VMAT for the lower extremity. Two attempts were made to obtain homogeneous dose in the overlapping region, i.e., applying two plans with different isocenters for the treatment of two fractions, and using a dose gradient matching scheme. The CT scans, including planning CT and IGRT FBCT, were stitched to a whole body CT scan for dose distribution evaluation.ResultsThe average beam-on time of Planupper is 30.6 min, ranging from 24.9 to 37.5 min, and the average beam-on time of Planlower is 6.3 min, ranging from 5.7 to 8.2 min. For the planned dose distribution, the 94.79% of the PTVbone is covered by the prescription dose of 10 Gy (V10), and the 94.68% of the PTVlymph is covered by the prescription dose of 12 Gy (V12). For the re-calculated dose distribution, the 92.17% of the PTVbone is covered by the prescription dose of 10 Gy (V10), and the 90.07% of the PTVlymph is covered by the prescription dose of 12 Gy (V12). The results showed that there is a significant difference (p < 0.05) between planning V10, V12 and delivery V10, V12. There is no significant difference (p > 0.05) between planned dose and re-calculated dose on selected organs, except for right lens (p < 0.05, Dmax). The actual delivered maximum dose of right lens is apparently larger than the planned dose of it.ConclusionTMLI treatment can be performed on the CT-linac with clinical acceptable quality and high efficiency. Evaluation of the recalculated dose on IGRT FBCT suggests the treatment was delivered with adequate target coverage.

Abstract Purpose Hematopoietic stem cell transplantation (HSCT) is a curative option for various hematologic malignancies (HM), however, the risk of relapse hampers favorable HSCT outcomes. Augmentation of irradiation to sites of disease is one potential strategy to overcome this risk. This study evaluated the feasibility of radiation dose escalation of total marrow and lymphoid irradiation (TMLI) as part of the conditioning regimen prior to HSCT. Methods and Materials 53 patients (5 acute myelogenous leukemia (AML), 29 acute lymphoblastic leukemia (ALL), 17 non-Hodgkin’s lymphoma (NHL), 2 mixed acute leukemia (MAL)) received conditioning radiation treatment with TMLI 10 Gy (8 Gy to bone marrow (BM), 10 Gy to involved lymphatic sanctuary sites in 2 fractions per day). 36 patients (5 AML, 26 ALL, 2 NHL, 3 MAL) underwent the radiation treatment with TMLI 12 Gy (8 Gy to BM, 12 Gy to involved lymphatic sanctuary sites in 2 fractions per day) before HSCT. Results The median age of patients receiving TMLI 10 Gy and 12 Gy was 24 (4–47) and 27 (8–55) years old, respectively. Median dose of organs at risk (OARs) was down-regulated by 27% − 79% and 11% − 83% of the prescription dose at TMLI 10 Gy and 12 Gy compared to standard total body irradiation (TBI). Grade 1–2 acute toxicities were primarily observed. The 2 years progression-free survival (PFS) was 73.6% at TMLI 10 Gy and 84.8% at TMLI 12 Gy (95% CI: 0.15, 1.33) and, and the 2 years overall survival (OS) was 79.1% and 65.7% respectively (95% CI: 0.28, 2.15). The 2-year relapse rate was 19% and 11%, and the non-relapse mortality was 9% and 22% at TMLI 10 Gy and 12 Gy, respectively. Conclusions This study suggests that the relapse rate and 2 years PFS of HM are considerably improved when TMLI is performed prior to HSCT, which will offer an effective strategy for treating these diseases.

Abstract Background: A novel CT-linac (kilovolt fan-beam CT-linac) has been introduced into total marrow and lymphoid irradiation (TMLI) treatment. Its integrated kilovolt fan-beam CT scanner enables accurate evaluation of the dose distribution difference between plan and delivery, which is crucial for the TMLI treatment improvement for the future. Purpose: This study evaluated the technical feasibility of kilovolt fan-beam CT-linacfor TMLI treatment and investigated the true dose distribution of the delivery. Methods: 11 sets of data from 5 male and 6 female patients who had underwent the TMLI treatment with uRT-linac 506c were selected for this study. The planning target volumes consist of all skeletal bones exclusion of the mandible and lymphatic sanctuary sites. A planned dose of 10Gy was prescribed to all skeletal bones exclusion of the mandible in two fractions and 12Gy in two fractions was prescribed to lymphatic sanctuary sites. Each TMLI plan contained two sub-plans, one dynamic IMRT for the upper body and the other VMAT for the lower extremity. Two attempts were made to obtain homogeneous dose in the overlapping region, i.e., applying two plans with different isocenters for the treatment of two fractions, and using a dose gradient matching scheme. The CT scans, including planning CT and fan-beam CT (obtained during image-guided radiation therapy) were stitched to a whole body CT scan for dose distribution evaluation. Results: Firstly, the kilovolt fan-beam CT-linac can provide the adequate target dose coverage (90% for planning and delivery) and critical organ sparing that satisfied the clinical requirements. Secondly, the beam-on time of kilovolt fan-beam CT-linac is apparently shorter than helical tomotherapy for the TMLI treatment. Thirdly, there exists the dose distribution difference of PTVs between plan and delivery (p<0.05, Wilcoxon signed-rank test), but the PTV coverage of delivery is clinically acceptable (larger than 90%). There is no significant difference (p>0.05) between the dose distribution of the plan and delivery for most organs at risk, except for right len. Fourthly, for the treatment delivery, applying two plans with different isocenters for one patient in two fractions performed better than employing only one plan for one patient in two fractions on PTV coverage for PTVbone, maximum dose for small bowel, heart, and liver. Conclusion: This radiation therapy treatment planning has proved to be effective. This research first exhibited that the dose difference between planning and delivery was evaluated, which is important for treatment evaluation and plan improvement for the future studies.

[This corrects the article DOI: 10.7150/ijbs.59430.].

ObjectiveThe aim of this study was to investigate the impact of collimator angle optimization in single-isocenter coplanar volume modulated arc therapy (VMAT) stereotactic radiosurgery (SRS) for multiple metastases with respect to dosimetric quality and treatment delivery efficiency. In particular, this is achieved by a novel algorithm of sub-arc collimator angle optimization (SACAO).MethodsTwenty patients with multiple brain metastases were retrospectively included in this study. A multi-leaf collimator (MLC) conformity index (MCI) that is defined as the ratio of the area of target projection in the beam’s eye view (BEV) to the related area fitted by MLC was applied. Accordingly, for each control point, 180 MCI values were calculated with a collimator angle interval of 1°. A two-dimensional heatmap of MCI as a function of control point and collimator angle for each full arc was generated. The optimal segmentation of sub-arcs was achieved by avoiding the worst MCI at each control point. Then, the optimal collimator angle for each sub-arc would be determined by maximizing the summation of MCI. Each patient was scheduled to undergo single-center coplanar VMAT SRS based on either the novel SACAO algorithm or the conventional VMAT with static collimator angle (ST-VMAT). The dosimetric parameters, field sizes, and the monitoring units (Mus) were evaluated.ResultsThe mean dose-volumetric parameters for the target volume of SACAO were comparable to ST-VMAT, while the conformity index (CI), homogeneity index (HI), and gradient index (GI) were reduced by SACAO. Improved sparing of organs at risk (OARs) was also obtained by SACAO. In particular, the SACAO method significantly (p < 0.01) reduced the field size (76.59 ± 32.55 vs. 131.95 ± 56.71 cm2) and MUs (655.35 ± 71.99 vs. 729.85 ± 73.52) by 41.11%.ConclusionsThe SACAO method could be superior in improving the CI, HI, and GI of the targets as well as normal tissue sparing for multiple brain metastases SRS. In particular, SACAO has the potential of increasing treatment efficiency in terms of field size and MU.

目的 评价2种基于人工智能方法自动勾画软件用于勾画胸部危及器官(OAR)效果的差异.方法 采用AccuContour和United Imaging软件自动勾画24例非小细胞肺癌患者胸部OAR,包括心脏、左肺、右肺、食管及脊髓;以勾画时间、豪斯多夫距离(HD)、形状相似性指数(DSC)及平均最小距离(MDA)评价勾画效果.结果 United Imaging软件勾画时间明显短于AccuContour软件(P＜0.05).2种软件勾画的心脏HD、DSC及MDA差异均具有统计学意义(P均＜0.05).AccuContour软件勾画的右肺HD明显小于United Imaging(P＜0.05).2种软件勾画食管的HD、DSC及MDA差异均有统计学意义(P均＜0.05),United Imaging软件勾画的左肺DSC明显大于AccuContour软件(P＜0.05),MDA则明显小于AccuContour软件(P＜0.05).2种软件勾画的脊髓各项参数差异均无统计学意义(P均＞0.05).结论 AccuContour3.0和United Imaging软件自动勾画胸部不同解剖结构的效果存在差异,且二者各有所长;其勾画肺部和心脏的效果均较好,勾画食管和脊髓效果均稍差.

Purpose: Total body irradiation (TBI) has been widely utilized as part of the conditioning regimen for hematopoietic stem cell transplantation (HSCT), but is associated with significant toxicities. Targeted TBI using helical Tomotherapy allows precise and homogeneous tumor coverage and excellent sparing of organs at risk. The purpose of this study was to evaluate the clinical outcomes of a novel hypofractionation strategy for patients receiving total marrow and involved lymphoid irradiation (TMLI) as part of the conditioning regimen before HSCT. Methods and Materials: 61 patients (7 acute myelogenous leukemia (AML), 33 acute lymphoblastic leukemia (ALL), 18 non-Hodgkin's lymphoma (NHL), 3 mixed acute leukemia (MAL)) received conditioning radiation treatment with TMLI (8 Gy to bone marrow, 10 Gy to involved field in 2 fractions per day) in conjunction with chemotherapy before transplantation. Results: The median age of 61 patients with TMLI was 24 (4-54) years. The prescribed dose covered the entire bone and involved target volume, and the dose of organs at risk (OAR) was reduced by 28%-78% of the prescription dose. Grade 1-2 nausea and vomiting occurred in 12 patients and grade 1-2 pain in 6 patients during radiotherapy. Fatigue occurred in 16 patients. 2 patients had diarrhea, enteritis, and 1 patient had fever. None of patient had grade 3-4 non-hematologic adverse reactions. Late (30 days after HSCT) grade 2 toxicities including reversible enteritis occurred in 3 patients. 5 patients developed infectious pneumonia. The 2 years progression-free survival (PFS) was 64.1% (95% CI: 0.16-0.22) and overall survival (OS) was 74.7% (95% CI: 0.19-0.24) for the 61 patients who had received their planned HSCT. The 2-year non-relapse mortality was significantly reduced to 5% in this patient cohort. Conclusions: This study demonstrates that hypo-fractionated TMLI (8 Gy to bone marrow, 10 Gy to involved field in a single day) as a conditioning regimen for lymphoma and acute leukemia was feasible and the clinical outcomes were acceptable. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of European Society for Radiotherapy and Oncology.

Mucin 3A (MUC3A) is highly expressed in non-small cell lung cancer (NSCLC), but its functions and effects on clinical outcomes are not well understood. Tissue microarray of 92 NSCLC samples indicated that high levels of MUC3A were associated with poor prognosis, advanced staging, and low differentiation. MUC3A knockdown significantly suppressed NSCLC cell proliferation and induced G1/S accumulation via downregulating cell cycle checkpoints. MUC3A knockdown also inhibited tumor growth in vivo and had synergistic effects with radiation. MUC3A knockdown increased radiation-induced DNA double strain breaks and γ-H2AX phosphorylation in NSCLC cells. MUC3A downregulation inhibited the BRCA-1/RAD51 pathway and nucleus translocation of P53 and XCRR6, suggesting that MUC3A promoted DNA damage repair and attenuated radiation sensitivity. MUC3A knockdown also resulted in less nucleus translocation of RELA and P53 in vivo. Immunoprecipitation revealed that MUC3A interacted with RELA and activated the NFκB pathway via promoting RELA phosphorylation and interfering the binding of RELA to IκB. Our studies indicated that MUC3A was a potential oncogene and associated with unfavorable clinical outcomes. NSCLC patients with a high MUC3A level, who should be more frequent follow-up and might benefit less from radiotherapy.