Spatially fractionated radiation therapy (SFRT) produces alternating high-dose peak and low-dose valley regions within tumors and provides a dose-modulation strategy for bulky tumors. This study evaluated the feasibility and dosimetric advantages of a jaw-partitioned volumetric modulated arc therapy (JP-VMAT) technique for improving the peak-to-valley dose ratio (PVDR) in 3D-GRID and 3D-lattice SFRT. Twenty-five patients with bulky solid tumors were retrospectively included. Four VMAT-SFRT plans were generated for each patient: GRID_JP, GRID_FOJ, LTV_JP, and LTV_FOJ. All plans were prescribed 18 Gy in a single fraction. JP-VMAT was compared with conventional full-open-jaw VMAT (FOJ-VMAT) in terms of peak-dose coverage, gradient index (GI), PVDR, valley-region dose, organs-at-risk (OARs) dose, monitor units (MUs), and plan complexity metric (CM). Correlations between gross tumor volume (GTV) and the magnitude of dosimetric improvement were analyzed. Patient-specific ArcCHECK quality assurance was performed only for the JP-VMAT plans; FOJ-VMAT plans were not measured. JP-VMAT maintained high-dose coverage of the peak-dose structures in both GRID and LTV plans. Compared with FOJ-VMAT, JP-VMAT significantly reduced GI from 11.18 to 9.48 in GRID plans and from 14.06 to 11.03 in LTV plans (both p < 0.001). JP-VMAT increased PVDR_Dmean and PVDR_D50
Abstract Background Concurrent cisplatin and radiotherapy frequently cause severe acute hematologic toxicity. This study investigated whether lymphocyte apoptosis, quantified via the γ-H2AX pan-nuclear immunostaining assay, can serve as a reliable biomarker for the acute hematologic side effects of combined chemoradiation. Methods Blood samples were collected from cancer patients and healthy controls. Lymphocyte apoptosis was evaluated using the γ-H2AX pan-nuclear assay following in vitro and in vivo exposure to cisplatin and ionizing radiation (IR). In PBMCs, γ-H2AX results strongly correlated with conventional caspase-3 (r = 0.9736) and annexin V (r = 0.9780) apoptosis assays. Additionally, in vitro experiments assessed how phytohemagglutinin-L (PHA-L)-induced lymphocyte proliferation influences the combined effects of cisplatin and IR on apoptosis, alongside the regulatory role of the ATM protein. Results In vitro, cisplatin increased lymphocyte apoptosis asymptotically, plateauing at 10 µg/ml (11.6 ± 5.0%). Combined cisplatin and IR treatment increased apoptosis in a strictly additive manner (radiation effect: p < 0.0001), with no significant synergistic interaction effect between the two modalities (p = 0.22). The apoptotic effect level of in vivo cisplatin administration did not differ significantly from the maximum effect observed following a 1-hour in vitro exposure to high cisplatin concentrations. In vivo, the additive effect of cisplatin on IR-induced apoptosis peaked up to 3 days post-administration before returning to baseline by day 6. Consistent with these findings, cisplatin and radiation induced a significant, additive increase in apoptosis within PHA-L-stimulated lymphocytes. Inhibition of ATM has no effect on apoptosis following treatment with cisplatin and IR. Conclusions The γ-H2AX pan-nuclear assay provides a valid, reliable method for quantifying radiation- and chemotherapy-induced lymphocyte damage. The time-dependent, additive toxicity observed indicates a critical clinical window (up to 3 days post-cisplatin) for maximum hematologic damage, allowing for optimization of treatment schedules. Clinical trial number Not applicable.
Stereotactic re-irradiation (re-SRT) is a promising salvage treatment for locally recurrent brain metastases (BMs) after prior stereotactic radiotherapy (SRT), but its feasibility and safety remain insufficiently validated. A systematic search was conducted for studies involving patients who received re-SRT, following PRISMA guidelines. Pooled local control rate (LCR), overall survival (OS), and radiation necrosis (RN) rates were calculated using a random-effects model. Meta-regression analyses were conducted to evaluate the relationship between variables and outcomes. Logistic dose–response models were hypothetically constructed for tumor control probability (TCP) in terms of the biological effective dose using an α/β of 10 Gy (BED10). Fourteen studies (687 patients, 896 BMs) were included, with a median BED10 of 50.4 Gy. Pooled 1-year LCR and OS rate were 76
Abstract Purpose Deep inspiration breath hold (DIBH) is widely used to reduce cardiac dose in left-sided breast radiotherapy. However, the reliability of DIBH at CT simulation, has not been systematically evaluated despite the importance of CT simulation as the basis for treatment planning. We investigated the clinical impact of surface-guided breathing training on DIBH reliability and cardiac dose sparing. Methods In this retrospective cohort study, 115 breast cancer patients undergoing DIBH CT simulation were analyzed before and after implementation of surface-guided breathing training using an SGRT system. DIBH performance was quantified by partial lung volume increase (PLVI) and breath-hold variability. Correlations between external surface motion and internal DIBH depth were assessed. Cardiac dose metrics were compared, with a subgroup analysis for patients receiving lymphatic drainage area (LDA) irradiation. Results Prior to training, insufficient DIBH CTs—including negative PLVI cases—were observed. After training implementation, all CT scans were acquired in intended breath-hold states, eliminating insufficient DIBH acquisitions. Mean PLVI increased by ~ 9%, and breath-hold variability decreased by ~ 26%. Sternum motion correlated most strongly with PLVI, with multiregion surface monitoring yielding the highest internal correlation. These improvements were reflected in significant reductions in cardiac dose, particularly in the LDA subgroup, with selected heart dose metrics reduced up to 96%, while maintaining target coverage. Conclusions DIBH at CT simulation with surface-guided breathing training proves to be reliable. The training prevents planning CTs in wrong breathing states and thus enables clinically meaningful cardiac dose reduction in breast radiotherapy.
Abstract Background Deep inspiration breath-hold (DIBH) is a radiotherapy standard technique for cardiac-sparing in breast cancer, particularly for left-sided tumors. However, not all patients can successfully complete DIBH RT in clinical routine, necessitating conversion to free breathing (FB) techniques and replanning. This study aimed to identify clinical factors predictive of DIBH feasibility to optimize patient selection and resource utilization. Methods This retrospective study analyzed all patients ( n = 1920) who underwent curative postoperative breast cancer radiotherapy at our institution between May 2020 and December 2024. All patients underwent initial DIBH feasibility assessment and were evaluated for completion of radiotherapy with DIBH or conversion to FB technique. A detailed subanalysis was performed for all patients treated in 2023 ( n = 470). Patient-related factors including age, body mass index (BMI), Karnofsky Performance Status (KPS), Charlson Comorbidity Index (CCI), pulmonary comorbidities, smoking status, and geometric surface distance between DIBH and FB planning scans were collected for the subanalysis. Results Across the entire cohort (years 2020–2024) of 1,920 patients, 78 replannings (4%) occurred due to conversion from DIBH to free breathing. Increasing age (cut-off of 63 years) was significantly associated with higher replanning rates ( p = 0.001). In the 2023 subanalysis ( n = 470), pulmonary comorbidities ( p = 0.008), higher CCI ( p = 0.044), and a geometric surface distance of below 1 cm between DIBH and FB CT scans ( p = 0.0001) were significant predictors of replanning. The Karnofsky Performance Score, BMI, and smoking status showed no significant association with replanning. Conclusions Age, pulmonary comorbidities, overall comorbidity burden, and insufficient geometric displacement are significant predictors of DIBH failure in breast cancer radiotherapy. These readily available clinical parameters can optimize patient selection algorithms and inform decisions regarding dual CT simulation workflows. A risk-stratified approach incorporating these factors may reduce unnecessary imaging, decrease planning burden, and improve resource allocation while maintaining optimal cardiac protection for appropriate candidates. Clinical trial number The study was registered in the German Clinical Trials Register (DRKS; registration number: DRKS00038550) on 22 December 2025 ( https://www.drks.de/ ).
Preserving brain function is becoming an important goal in stereotactic radiotherapy, with increasing attention to the potential impact of radiation dose on functional neuroanatomy. This study investigated whether including these functional brain regions as optimization objectives during SRT for brain metastases can achieve measurable dose reductions. A retrospective analysis was conducted on 41 patients with single brain metastases treated with CyberKnife SRT across two institutions. Patients received 22 Gy in one fraction or 30 Gy in three fractions, according to lesion size and location. For each case, the clinical plan (TPCL) was generated according to international guidelines. Functional regions within 3 cm of the target were automatically segmented using BrainLab’s multimodal MRI workflow. A function-sparing plan (TPFS) was then re-optimized using the same target and OAR criteria while incorporating functional regions as avoidance structures. For each structure, Dmean and Dmax were extracted; for small-volume regions (< 0.5 cc), only Dmax was evaluated. Relative dose variation (ΔD) from TPCL to TPFS was calculated, and differences were assessed using the Wilcoxon signed-rank test. Automatic segmentation identified 29 functional regions across the cohort, ranging from large cortical gyri to small subcortical and allocortical nuclei. TPFS preserved full target coverage, with variations in VDpre < 0.5
The sparing effect of FLASH irradiation with ultrahigh dose rates (UHDR), by applying high dose fractions in less than one second, on adverse reaction in many normal tissues but not on tumour control has the potential to widen the therapeutic window and advance cancer radiotherapy. However, the mechanism is poorly understood, preventing its optimal application in the clinic. Here we review the current knowledge of radiation-induced radicals and their reactions, including time factors which are rarely considered. Furthermore, experimental in vitro and in vivo data in the framework of prevailing hypotheses, and the role of low oxygen concentrations and reoxygenation, are discussed. Finally, potential protective mechanisms are considered based on such reactions and the role of oxygen. We argue that more than one mechanism may contribute to dose-rate dependent protection, and that differences exist between protective mechanisms in vitro and in vivo. Furthermore, we propose a new protective reaction linking radiation chemistry to the role of oxygen in FLASH irradiation and incorporating the differential responses of normal tissue and tumours.
Dual-layer multileaf collimator (MLC) accelerators, such as Halcyon, are increasingly used in clinical settings; however, the ability of treatment planning systems (TPS) to effectively optimize treatment plans for such accelerators remains an important consideration. This study evaluates the feasibility of using uTPS to optimize treatment plans for dual-layer MLC accelerators, with Eclipse as a clinical reference. Standard radiation data from the Halcyon 2.0 accelerator were used to model the beam in the uTPS (Shanghai United Imaging Healthcare Co., Ltd., version R001). Twenty cases were selected, with five each for hypopharyngeal, esophageal, breast, and cervical cancers. Volumetric modulated arc therapy plans were generated using the uTPS stochastic platform optimizer and the Eclipse photon optimizer (PO). All plans were calculated using the Acuros external beam (AXB) algorithm for dosimetric comparison. Key indicators, such as the conformity index (CI), homogeneity index (HI), and organ-at-risk (OAR) doses, were analyzed and compared. The feasibility of delivering uTPS plans on the Halcyon accelerator was validated. The dosimetric accuracy was confirmed using ArcCheck, and Wilcoxon signed-rank tests with Benjamini–Hochberg false discovery rate correction were performed. uTPS and Eclipse plans exhibited similar dosimetric qualities for esophageal and cervical cancer cases, with no significant differences in CI, HI, and OAR doses. However, uTPS demonstrated superior OAR sparing in specific cases: in hypopharyngeal cancer, uTPS significantly reduced the brainstem D_0.1cc by 34.48
The Korean Radiation Oncology Group 19 − 09 multi-institutional clinical trial investigates the effect of regional nodal irradiation (RNI) omission on regional recurrence rates after neoadjuvant chemotherapy followed by breast-conserving surgery, and sentinel lymph node biopsy in cT1-3N1 and ypN0 breast cancer patients. This mid-trial analysis evaluates dosimetric deviations among enrolled patients using an artificial intelligence (AI) auto-contouring engine. We analyzed dose-volume histograms of 366 patients enrolled from eight institutions based on an AI auto-contoured reference structure set. Of these, 176 received whole breast and regional nodal irradiation (WBI + RNI), while 190 received whole breast irradiation only (WBI). Dosimetric outliers were observed in both groups. In the WBI + RNI group, 25 (14
This study aimed to develop and validate a novel interpretable framework integrating a deep segmentation network with multimodal radiomics to improve the prediction performance of radiation proctitis (RP) in cervical cancer patients undergoing radiotherapy. This retrospective study included 650 cervical cancer patients, who were divided into training and internal device test sets, and independent device test set, based on different computed tomography (CT) scanners. A Mamba-enhanced deep learning network was constructed to enhance global modeling capability in pelvic anatomical structures, providing reliable regions of interest segmentation for radiomics and adaptive radiotherapy. In multimodal radiomics approach, foundation model features were integrated with radiomics and clinical data to mitigate inherent bias in training data, thereby enhancing the prediction of RP. Shapley Additive exPlanations (SHAP) technology was employed to explain the contributions of multimodal features to the prediction performance. The segmentation model achieved dice similarity coefficients (DSC) of 90.76
Severe metal artifacts in cervical brachytherapy CT scans obscure critical anatomical structures and applicator geometry. Existing metal artifact reduction (MAR) models are inadequate in addressing these complex artifacts, leading to uncertainties in organs at risk (OARs) delineation and dose optimization that may compromise treatment safety and precision. This study aims to develop and validate a task-specific, synthetic-to-clinical deep learning framework for MAR in cervical brachytherapy CT scans. The synthetic dataset consisted of 500 external beam radiotherapy CT scans with simulated applicator artifacts from March 2021-April 2025. An independent clinical validation cohort included 50 brachytherapy CT scans. A proposed task-specific framework was applied to baseline deep learning MAR models, including InDuDoNet+, OSCNet+, OSCNet, and ADN. The performances of these models were compared against standard linear interpolation (LI) method and uncorrected images. Performance was assessed using quantitative metrics (peak signal-to-noise ratio [PSNR] and structural similarity index measure [SSIM]) on synthetic data, and clinical metrics (artifact index, applicator reconstruction error, and geometric accuracy of OARs) on clinical data. Additionally, three experienced radiologists independently evaluated the image quality using a 5-point Likert scale. For the synthetic dataset, the proposed task-specific models significantly outperformed baseline models, with improvements of 32.42
Due to the limited number of studies on MR-only stereotactic radiotherapy (SRT) for brain metastases using CyberKnife in the literature, this study systematically evaluates the dose calculations and image guidance accuracy of synthetic CT (sCT) and sCT-derived digital reconstructed radiographs (sDRRs), to assess the feasibility of clinical MR-only workflow implementation in CyberKnife SRT for brain metastases. We developed a machine learning model trained on T1-weighted MR and corresponding CT images from 50 patients with brain metastases who had previously undergone CyberKnife treatment, with images from an additional 18 patients used to test the feasibility of the MR-only workflow. The Mean Absolute Error (MAE), Structural Similarity Index (SSIM), Peak Signal-to-Noise Ratio (PSNR) and the Dice Similarity Coefficient (DSC) were used to evaluate the image quality of sCT and sDRR. For dosimetric evaluation, the sCT-based and transferred plans (namely, the original planning parameters were transferred to the sCT images for dose recalculation) was compared with the plans based on the real CT images (rCT) using DVH metrics. For image-guided positioning accuracy, the 2D errors generated by registering DRR with the digital radiography images (DRs) were converted into translational and rotational couch shifts using a geometric back-projection method, thereby assessing the consistency of positioning accuracy between the sDRRs with the rCT-derived DRRs (rDRRs). The sCT images had a mean MAE of 10.08 ± 2.14 HU, a SSIM of 0.98 ± 0.01, and a PSNR of 34.73 ± 1.27 dB, and the overall sDRRs maintained high image quality (MAE: 37.36 ± 9.31 HU; SSIM: 0.95 ± 0.03; PSNR: 31.41 ± 7.14 dB). Large OARs (brainstem/eyeballs) had high DSC (> 0.80), while small OARs (lenses/optic pathway) had lower DSC. The dosimetric parameters of PTV and OARs under both planning strategies showed no statistically significant difference from the rCT-based plans (p > 0.05). When using sDRRs for image guidance, the translational errors were submillimeter, and the rotational errors had a wider distribution but mean values within robotic correction range, there was no statistical difference compared with that of the rDRRs (p > 0.05). The proposed model can generate accurate sCT for brain metastases, and the feasibility of the MR-only in CyberKnife SRT has been verified. This study is retrospectively registered in the Clinical trial Center of Zhejiang Cancer Hospital in Jan 1th, 2024 (No. MR-33-24-003134).
To predict symptomatic radiation pneumonitis (RP) in locally advanced non-small cell lung cancer (LA-NSCLC) patients by handcrafted radiomics (HCR) and deep learning (DL) features of three different regions of interest (ROIs) in normal lung tissue. Ninety LA-NSCLC patients from Center A were collected as the development cohort, and an additional 57 patients from Center B were collected as the external validation set. Clinical data and lung dose-volume parameters were collected from the patients, and univariate analysis was conducted. Three ROIs in lung were delineated in pre-radiotherapy CT images: Lung-PTV, Lung-GTV, and PTV-GTV. For each ROI, 1046 HCR features and 512 DL features were respectively extracted, and then correlated. For each ROI, three models (HCR, DLR, and a hybrid model) were developed with feature selection via Spearman correlation, mRMR, the LASSO method, and SVM-based modeling. And finally, their performance was evaluated and compared using AUC values from ROC curves. The optimal model was selected by comparing the best AUC through internal validation results, and then external validation was conducted. Calibration and decision curve analyses were used to evaluate the model. In the development cohort, univariate analysis revealed no statistically significant associations with RP. The correlation analysis revealed a weak correlation between HCR and DL features. In internal validation, for Lung-PTV, Lung-GTV and PTV-GTV, HCR models achieved AUCs of 0.658 (95
Accurate motion tracking in magnetic resonance imaging-guided radiotherapy (MRIgRT) is essential for effective treatment delivery. This study aimed to enhance motion tracking precision in MRIgRT through an automatic real-time markerless tracking method using an enhanced Tracking-Learning-Detection (ETLD) framework combined with automatic segmentation, eliminating the need for pre-training. We developed a novel motion tracking and segmentation method by integrating the ETLD framework with an improved Chan-Vese (ICV) model, termed ETLD + ICV. The ETLD framework was upgraded for real-time MRIgRT, including search process optimization, an enhanced median-flow tracker, and dynamic detection region adjustments. It receives 3.5D MRI data as input and outputs the location prediction of the target volume for each frame. Based on this, ICV was used for precise target volume coverage, refining the segmented region frame by frame using tracking results, with optimized key parameters. The method requires no pre-training and was tested on 3.5D MRI scans from 10 patients with liver metastases. No-reference image quality assessment and manual verification were used to filter out low-quality image data. Comprehensive statistical analyses were performed to assess the statistical significance of differences between experimental outcomes (p < 0.05). In addition, comparative experiments based on an external benchmark dataset were conducted to further evaluate the performance of the proposed method. Evaluation across 106,000 frames from 77 treatment fractions demonstrated sub-millimeter tracking errors of less than 0.8 mm, with over 99
Abstract Purpose Stereotactic body radiation therapy (SBRT) is widely used for pulmonary oligometastatic disease. Guideline-based regimens target a biologically effective dose $$(\textrm{BED}_{10}) \geq100~\textrm{Gy}$$ ; However, this threshold may not be achievable in patients with limited physiological reserve or ultracentral lesions. We examined outcomes after SBRT with $$\textrm{BED}_{10} < 100~\textrm{Gy}$$ versus $$\textrm{BED}_{10}\geq100~\textrm{Gy}$$ in a consecutive cohort of patients with recurrent lung-only metastases. Methods and materials Consecutive patients treated with SBRT for recurrent lung-only metastases between January 2019 and December 2022 were retrospectively reviewed. Primary endpoints were overall survival (OS), progression-free survival (PFS), and freedom from local–regional progression (FFLP). Kaplan–Meier estimates were compared using log-rank tests, and univariable Cox proportional hazards models estimated hazard ratios (HRs) with 95% confidence intervals (CIs). A propensity-score inverse probability of treatment weighting (IPTW) analysis adjusted for age, Eastern Cooperative Oncology Group (ECOG) performance status, Charlson Comorbidity Index (CCI), lung primary status, and number of metastases. Results Fifty-three patients were included. Median OS was 47.3 months for $$\textrm{BED}_{10}\geq100~\textrm{Gy}$$ versus 34.3 months for $$\textrm{BED}_{10} < 100~\textrm{Gy}$$ (HR 1.45; 95% CI 0.66–3.16; $$p=0.35$$ ). Median PFS was 22.8 months versus 14.7 months (HR 1.59; 95% CI 0.82–3.11; $$p=0.17$$ ). For FFLP, the HR was 2.67 (95% CI 0.60–11.93; $$p=0.20$$ ). In IPTW-weighted models, $$\textrm{BED}_{10}\geq100~\textrm{Gy}$$ was not significantly associated with OS (HR 0.58; 95% CI 0.25–1.32; $$p=0.19$$ ) or PFS (HR 0.59; 95% CI 0.24–1.40; $$p=0.23$$ ). Conclusion In this retrospective cohort, $$\textrm{BED}_{10} < 100~\textrm{Gy}$$ was delivered to selected higher-risk patients on the basis of frailty, ultracentral anatomy, or both. Differences in OS, PFS, and FFLP compared with $$\textrm{BED}_{10}\geq100~\textrm{Gy}$$ did not reach statistical significance, and IPTW-weighted estimates were directionally consistent. These observations are consistent with the feasibility of sub-ablative SBRT in selected higher-risk patients when ablative dosing is not safely deliverable, and they define the patient population and dose parameters that warrant prospective, risk-stratified evaluation.
Small cell lung cancer (SCLC) frequently results in brain metastases, which significantly impact survival rates. Although whole-brain radiotherapy (WBRT) is the conventional approach, it is associated with neurocognitive side effects. Stereotactic radiotherapy (SRT) offers accurate targeting but lacks established guidelines for managing SCLC’s numerous metastases. This research conducted a comparative analysis of SRT, WBRT, and WBRT combined with a boost (WBRT+Boost) to inform clinical management strategies. A retrospective analysis was conducted involving 337 patients with SCLC who presented with brain metastases and were treated at Zhejiang Cancer Hospital between 2019 and 2026. The patient groups consisted of those receiving SRT (n = 95), WBRT alone (n = 181), and WBRT+Boost (n = 61). The primary endpoints of the study were intracranial progression-free survival (iPFS) and overall survival (OS). Statistical analyses employed Kaplan-Meier curves, log-rank tests, Cox proportional hazards models, and 1:1 propensity score matching (PSM) to control for confounding variables. Pre-PSM, SRT demonstrated a longer median OS compared to WBRT alone (13.47 vs. 8.27 months, P = 0.013), although the differences in iPFS were not statistically significant. Following PSM, the differences in OS diminished (SRT vs. WBRT: 11.77 vs. 8.70 months, P = 0.412), while the WBRT+Boost significantly improved iPFS compared to SRT (8.17 vs. 5.87 months, P = 0.021). Multivariate analysis identified a Karnofsky Performance Status (KPS) of ≥ 90 (HR, 0.63; P = 0.006) and the presence of synchronous metastases (HR, 0.62; P = 0.013) as factors associated with improved OS. Conversely, the presence of extracranial metastases (HR, 2.24; P < 0.001) and more than three brain lesions (HR, 1.44; P = 0.045) were linked to worse OS. Additionally, immunotherapy administered after radiotherapy was found to be protective. Radiotherapy modality did not significantly impact OS, but WBRT+Boost may enhance intracranial control. Immunotherapy integration is critical. Future prospective studies should define optimal strategies and synergy with immunotherapy. Not applicable.
The ZAP-X® Gyroscopic Radiosurgery® platform (ZAP Surgical Systems, Inc., San Carlos, CA, USA) is a novel self-shielded image-guided radiotherapy device developed for frameless stereotactic radiosurgery (SRS) and fractionated SRS (FSRS) of intracranial and cervical spine lesions. This article presents technical aspects and dosimetric results for SRS and FSRS using the ZAP-X system for meningioma patients. Unique technical aspects of our treatment workflow using the ZAP-X system encompassing computed tomography simulation, treatment planning, independent dose calculations, patient-specific quality assurance (PSQA) and treatment delivery were described. Eighteen single-lesion meningioma patients, who were treated following this workflow, were selected and divided into two groups (Group A [thirteen patients]: 25 Gy in 5 fractions, FSRS); Group B [five patients]: 15 Gy in a single fraction, SRS). Plan quality metrics, independent dose calculations and PSQA for each group were reviewed and analyzed. For Group A, mean age (range) was 60 years (35 years − 80 years) and mean planning target volume (PTV) (range) was 4.78 cc (2.10 cc − 9.38 cc). Mean (range) PTV coverage, prescribed isodose line, Paddick conformity index, gradient index, number of isocenters, number of beams, delivery time estimate per fraction and PSQA gamma passing rate were 99.5
For locally advanced rectal cancer (LARC), neoadjuvant chemoradiotherapy (nCRT) combined with total mesorectal excision has emerged as the standard therapeutic approach, as delineated in contemporary clinical guidelines. Pathological complete response (pCR) serves as a pivotal metric for assessing nCRT efficacy, with strong correlations to long-term survival outcomes and organ preservation strategies such as the “watch-and-wait” approach. However, inter-individual variability in treatment responses results in only approximately 20
Breast cancer radiotherapy and autoimmune myositis intersect in a clinically complex setting in which paraneoplastic disease, pre-existing inflammatory myopathy, and radiation-related muscle injury may overlap. Dermatomyositis is the idiopathic inflammatory myopathy most strongly associated with malignancy, and breast cancer is one of the solid tumours most frequently reported in cancer-associated myositis, particularly in anti-TIF1γ- and anti-NXP2-positive subsets. A structured narrative review of PubMed and Scopus was performed from database inception to March 2026. Evidence was synthesised qualitatively owing to limited and heterogeneous literature. Muscle symptoms during breast cancer treatment may reflect autoimmune, paraneoplastic, radiation-induced, fibrosis-related, or recall myositis. MRI is the most informative modality for pattern-based assessment, with FDG PET-CT and ultrasound providing complementary value in selected cases. Although direct disease-specific evidence is sparse and derives largely from retrospective series, mixed connective tissue disease cohorts, radiobiological studies, and case reports, radiotherapy does not appear to represent an automatic contraindication when disease activity, multidisciplinary evaluation, and conformal planning are taken into account. Breast cancer radiotherapy in patients with autoimmune or cancer-associated myositis requires structured differential diagnosis rather than categorical avoidance. Diagnostic assessment should integrate timing, field distribution, imaging, serology, systemic features, and treatment sequence. Further studies should refine risk stratification, muscle-specific dose constraints, and biomarkers distinguishing radiation-related from autoimmune or paraneoplastic myositis.
Radiation-induced endothelial dysfunction is a critical mechanism underlying long-term cardiovascular and multiorgan toxicity in cancer survivors after radiotherapy. This review integrates current evidence on the molecular pathogenesis, from initial endothelial apoptosis and senescence to the establishment of chronic pro-thrombotic and pro-inflammatory phenotypes involving various signalling pathways. Clinical data reveal that even low to moderate radiation doses can cause sustained endothelial injury, contributing not only to vascular diseases but also to common cerebrovascular and gastrointestinal complications. Advances in vascular imaging and circulating biomarkers facilitate earlier detection of subclinical damage. Promising protective strategies include statins, angiotensin-converting enzyme inhibitors, and pathway-targeted agents. Future research directions include the development of advanced preclinical models and the conduct of large-scale, prospective clinical studies to validate biomarkers and therapeutic interventions, ultimately aiming to integrate vascular preservation into personalized radiotherapy strategies.
