Contralateral Lung Research Articles

Dosimetric predictors of acute radiation pneumonitis and esophagitis in hypofractionated thoracic irradiation of non-small cell lung cancer patients with poor prognostic factors: Dosimetric predictors of acute radiation pneumonitis and esophagitis following hypofractionation in NSCLC

The proliferation rates of non-small cell lung cancer (NSCLC) and associated radiation resistance highlight the potential of hypofractionated radiation therapy (hypoRT). However, radiation pneumonitis and esophagitis remain dose-limiting adverse events. This study investigates dosimetric factors influencing the risk of pneumonitis and esophagitis in highly multimorbid patients undergoing moderately hypoRT. Forty-seven NSCLC patients with poor performance status treated between January 2014 and July 2021 were included. Dosimetric parameters including mean lung dose (MLD), percentage of normal (ipsi-/contralateral) lung volume (Vx) receiving ≥x Gy (x = 20, 18, 10, and 5 Gy); mean heart dose (MHD), percentage of the heart volume (HVx) receiving ≥x Gy (x = 20, 10, and 5 Gy); and mean esophageal dose (MED), percentage of esophagus volume (EVx) receiving ≥x Gy (x = 40, 30, 20, 18, 10, and 5 Gy) were analyzed retrospectively. Acute radiation pneumonitis/esophagitis events were assessed within 6/3 months posttreatment. Statistical analyses included random forests, binary logistic regression, and linear regression. Among the 47 patients with compromised lung function and poor prognostic factors, 8 (17%) and 26 (55%) patients developed all-grade pneumonitis or esophagitis, while 4 (9%) and 10 (21%) patients developed CTCAE grade ≥2 pneumonitis and esophagitis, respectively. Exploratory analyses suggest that V10, V18, and MLD values are associated with an increased risk of pneumonitis. Linear regressions confirmed this for MLD values greater than 9.2 Gy (P = .050). Additionally, higher V5 and V10 values in the contralateral lung were associated with a greater risk of pneumonitis (P = .013/P = .032). Dmax proved to be a significant predictor of esophagitis (P = .020). Moreover, evidence suggests that EV5 and EV40 may portend esophagitis onset. This study provides insights into dosimetric factors influencing pneumonitis/esophagitis development in NSCLC patients undergoing hypoRT. While MLD and Dmax emerged as significant predictors of pneumonitis and esophagitis, the small sample size limited the depth of conclusions. Further research with larger cohorts is warranted to validate these observations, potentially optimizing treatment planning and outcomes in this challenging patient population.

Impact of Tafamidis on [99mTc]Tc-pyrophosphate Scintigraphy in Ala97Ser Hereditary Transthyretin amyloid cardiomyopathy: significant initial reduction with stable Long-Term effects.

Tafamidis has shown potential in slowing disease progression in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). This study aimed to evaluate serial changes on [99mTc]Tc-pyrophosphate (PYP) scintigraphy during tafamidis treatment for hereditary ATTR-CM. We retrospectively analyzed a prospectively collected cohort of Ala97Ser (A97S) hereditary ATTR-CM patients treated with tafamidis (61mg/day) and a control group comprising A97S hereditary ATTR-CM patients who had not received disease-modifying medications. The tafamidis group was further divided into two cohorts: cohort A received [99mTc]Tc-PYP SPECT/CT scans at baseline, 1 year, and 2 years; cohort B at baseline, 2 years, and 3 years. Visual score, planar heart to contralateral lung (H/CL) ratio, and volumetric heart to lung (H/L) ratio were measured. Nineteen patients were enrolled in the tafamidis group and nine in the control group. After 2 years of follow-up, a significant decrease in volumetric H/L ratio (3.86 ± 0.91 to 3.01 ± 0.19, p < 0.001) was noted in the tafamidis group, while there was no significant change in the control group. When evaluated over time, a significant decrease in volumetric H/L ratio was observed during the first year of tafamidis treatment (3.75 ± 0.37 to 2.82 ± 0.15, p = 0.004), followed by stable [99mTc]Tc-PYP uptake in the subsequent two years (2.82 ± 0.15 to 2.83 ± 0.18, p = 0.934 and 3.20 ± 0.14 to 3.09 ± 0.16, p = 0.404, respectively). A significant reduction in [99mTc]Tc-PYP uptake was observed in hereditary ATTR-CM patients after tafamidis treatment, particularly within the first year. While the effect appeared to be sustained, stable [99mTc]Tc-PYP uptake without further significant reductions was observed in the subsequent years.

Phase 1-2 Study of Prone Hypofractionated Accelerated Breast and Nodal Intensity Modulated Radiation Therapy.

In patients with breast cancer, prone radiation therapy (RT) has been shown to reduce heart and lung dose. Though prone positioning is routinely used for whole breast RT, its use when treating the regional lymph nodes is not widespread. In this phase 1/2 trial for stage IB-IIA breast cancer treated with lumpectomy or mastectomy, patients received 40.5 Gy in 15 fractions to the breast or chest wall and regional lymph nodes with an integrated tumor bed boost for lumpectomy patients. Primary endpoints were grade >2 acute toxicity and dosimetric feasibility. Secondary endpoints were the incidence of resimulation to improve dosimetry and late toxicity. Exploratory endpoints were local recurrence, disease-free survival, distant recurrence-free survival, and overall survival. From 2009 to 2016, 97 patients were enrolled (68% lumpectomy and 32% mastectomy), among which 92 were treated in the prone position. Five patients were resimulated and treated supine. Among the prone-treated patients, there were no acute toxicities greater than grade 2. A total of 92%, 98%, and 89% met a planning target volume tumor V48 Gy ≥98%, breast V40.5 Gy ≥95%, and nodal V38.5 Gy ≥95%, respectively. All met the heart V5 Gy <5%, contralateral lung V5 Gy <15%, spinal cord dose maximum (Dmax) ≤37.5 Gy, esophagus V30 Gy <50%, and Dmax ≤40.5 Gy. Ninety-eight percent met the ipsilateral lung V10 Gy. Brachial plexus Dmax <42 Gy was met in 74% with a mean increase of 1.61 Gy (SD, 1.96 Gy) over the target. At a median follow-up of 8 years, grade 2 to 3 late toxicity was 23% for prone patients. There were 2 local recurrences (2%) and no chest wall or nodal recurrences. The 8-year distant recurrence-free survival, disease-free survival, and overall survival were 88% (95% CI, 81%-95%), 86% (95% CI, 78%-95%), and 91% (95% CI, 84%-98%), respectively. Toxicity was low, and outcomes were excellent in this prospective trial of prone hypofractionated nodal RT.

Clinical feasibility of Ethos auto-segmentation for adaptive whole-breast cancer treatment

IntroductionFollowing a preliminary work validating the technological feasibility of an adaptive workflow with Ethos for whole-breast cancer, this study aims to clinically evaluate the automatic segmentation generated by Ethos.Material and methodsTwenty patients initially treated on a TrueBeam accelerator for different breast cancer indications (right/left, lumpectomy/mastectomy) were replanned using the Ethos® emulator. The adaptive workflow was performed using 5 randomly selected extended CBCTs per patient. The contours generated by artificial intelligence (AI) included both breasts, the heart, and the lungs. The target volumes, specifically the tumor bed (CTV_Boost), internal mammary chain (CTV_IMC), and clavicular nodes (CTV_Nodes), were generated through rigid propagation. The CTV_Breast corresponds to the ipsilateral breast, excluding 5mm from the skin. Two radiation oncologists independently repeated the workflow and qualitatively assessed the accuracy of the contours using a scoring system from 3 (contour to be redone) to 0 (no correction needed). Quantitative evaluation was carried out using the Dice Similarity Coefficient (DSC), Hausdorff Distance (HD), surface Dice (sDSC) and the Added Path Length (APL). The interobserver variability (IOV) between the two observers was also assessed and served as a reference. Lastly, the dosimetric impact of contour correction was evaluated. The physician-validated contours were transferred onto the plans automatically generated by Ethos in adaptive mode. The dose prescription was 52.2Gy in 18 fractions for the boost, 42.3Gy for the breast, IMC, and nodes. The CTV/PTV margin was 2mm for all volumes, except for the IMC (5mm). Dose coverage (D98%) was assessed for the CTVs, while specific parameters for organs at risk (OAR) were evaluated: mean dose and V17Gy (relative volume receiving at least 17Gy) for the ipsilateral lung, mean dose and D2cc (dose received by 2cc volume) for the heart, the contralateral lung and breast.ResultsThe qualitative analysis showed that no correction or only minor corrections were needed for 98.6% of AI-generated contours and 86.7% of the target volumes. Regarding the quantitative analysis, Ethos’ contour generation outperformed inter-observer variability for all structures in terms of DSC, HD, sDSC and APL. Target volume coverage was achieved for 97.9%, 96.3%, 94.2% and 68.8% of the breast, IMC, nodes and boost CTVs, respectively. As for OARs, no significant differences in dosimetric parameters were observed.ConclusionThis study shows high accuracy of segmentation performed by Ethos for breast cancer, except for the CTV_Boost. Contouring practices for adaptive sessions were revised following this study to improve outcomes.

Diagnostic Performance of Imaging Methods in Predicting Lung Cancer Metastases.

This study aimed to investigate the possibility of distant organ metastasis using an algorithm developed to evaluate the morphology and localization of lung masses. Patients diagnosed with lung cancer between 2016 and 2023 were included. The lesion's morphological characteristics, proximity to important structures, and maximum standardized uptake value were recorded. Six common metastatic sites were identified: the contralateral lung, liver, brain, adrenal glands, bone, and other regions. The relationship between the characteristics of the mass and the metastatic location was investigated. A total of 383 patients (260 men, 68%) with malignant lung lesions with a mean ± SD age of 65.50 ± 12.34 years (range: 36-74 years) were included in the study. Among them, 242 were diagnosed with primary lung cancer, and 106 (43.8%) exhibited metastases to other organs with primary lung tumors. Distant organ metastases were most frequently detected in the bones (n = 45, 42.5%) and were more frequent in male patients and lesions adjacent to the ribs and bronchi, those involving mediastinal lymph nodes, irregular contours, and maximum standardized uptake values above 11.15 ± 5.67 (mean ± SD). Evaluating radiological imaging of malignant lesions in patients with lung cancer using an algorithm that considers morphological and neighborhood characteristics can provide predictive information regarding the possibility of metastasis of malignant lung lesions and the metastatic location.

Anesthetic Management for Pediatric Lung Resection: A Single-Center Retrospective Analysis.

Background Lung resection is a complex surgical procedure performed in children to address various pulmonary conditions. The success of this surgical intervention in these patients lies in a multidisciplinary approach, with anesthetic management playing a critical role in ensuring the safety and efficacy of the procedure. Methods After approval by the local ethics committee, clinical data of 17 pediatric patients who underwent lung resection in our hospital from January 2012 to December 2022 were retrospectively analyzed. Results A total of 16 patients underwent video-assisted thoracoscopic surgery (VATS), and only one patient underwent open thoracotomy.Most indications for this type of procedure are linked to cystic disease at a stage where respiratory function is not severely compromised. Lung resection procedures were conducted under general anesthesia and invasive blood pressure monitoring in all patients. Various methods, such as double-lumen endotracheal tubes (DLTs), bronchial blockers (BBs), and specialized endobronchial devices, were employed to selectively collapse the lung undergoing resection while maintaining ventilation in the contralateral lung. A multimodal analgesia regimen, combining systemic analgesia with regional anesthesia techniques (epidural or regional trunk blocks), was employed. Conclusions Thorough preoperative preparation is critical for a desirable outcome in pediatric patients undergoing lung resection. The need for one-lung ventilation (OLV) presents challenges, especially in younger ages, where this surgery is more commonly performed. The use of BBs is often necessary, along with the likelihood of their extraluminal application. In recent years, to reduce the risks associated with thoracic epidural analgesia, regional trunk blocks have been described as a safe and effective alternative in pain management.

Lung adenocarcinomas with mucinous histology: clinical, genomic, and immune microenvironment characterization and outcomes to immunotherapy-based treatments and KRASG12C inhibitors

Approximately 10% of lung adenocarcinomas (LUADs) have mucinous histology (LUADMuc), which is associated with a light/absent smoking history and a high prevalence of KRAS mutations. We sought to characterize LUADMuc by comparing it with LUAD without mucinous histology (LUADnon-muc) and determine the relative benefit of current treatments. Patients with LUAD from five institutions and The Cancer Genome Atlas Pan-Cancer Atlas classified as LUADMuc or LUADnon-muc were included. Clinicopathologic, genomic, immunophenotypic, transcriptional features, and treatment outcomes were compared between LUADMuc and LUADnon-muc. Of 4082 patients with LUAD, 9.9% had LUADMuc. Compared with LUADnon-muc, patients with LUADMuc had a lighter smoking history (median 15 versus 20 pack-years; P= 0.008), lower programmed death-ligand 1 (PD-L1) tumor proportion score (median 0% versus 5%, P < 0.0001), and lower tumor mutation burden (median 6.8 versus 8.5 mutations/megabase, P < 0.0001). Mutations in KRAS, NKX2-1 [thyroid transcription factor 1 (TTF-1)], STK11, SMARCA4, GNAS, and ALK rearrangements were enriched in LUADMuc, while TP53, EGFR, BRAF, and MET mutations were enriched in LUADnon-muc. At stage IV diagnosis, LUADMuc was more likely to have contralateral lung metastasis (55.2% versus 36.9%, P < 0.0001) and less likely to have brain metastases (23.3% versus 41.9%, P < 0.0001). Compared with LUADnon-muc, LUADMuc cases showed lower intratumor CD8+, PD-1+, CD8+PD-1+, and FOXP3+ cells. Among metastatic cases receiving immune checkpoint inhibitors, compared with LUADnon-muc (n= 1511), LUADMuc (n= 112) had a lower objective response rate (ORR 8.4% versus 25.9%, P < 0.0001), and shorter median progression-free survival (mPFS 2.6 versus 3.9 months, P < 0.0001) and overall survival (mOS 9.9 versus 17.2 months, P < 0.0001). Similarly, patients with LUADMuc had worse outcomes to chemoimmunotherapy. LUADMuc (n= 18) and LUADnon-muc (n= 150) had similar ORR (16.7% versus 34.9%, P= 0.12) and mPFS (4.6 versus 5.6 months, P= 0.17) to treatment with KRASG12C inhibitors, but LUADMuc had shorter mOS (6.8 versus 10.8 months, P= 0.018). LUADMuc represents a distinct LUAD subpopulation with unique clinicopathologic, genomic, immunophenotypic, and transcriptional features, achieving worse outcomes to standard immunotherapy-based treatments.

Improvement of plan quality in whole-breast radiation following BCS using feasibility DVH by less-experienced planners.

Variability in plan quality of radiotherapy is commonly attributed to the planner's skill rather than technological parameters. While experienced planners can set reasonable parameters before optimization, less experienced planners face challenges. This study aimed to assess the quality of volumetric-modulated arc therapy (VMAT) in patients with left-sided breast cancer following breast-conserving surgery. Twenty-eight patients requiring whole-breast irradiation were randomly selected for inclusion. Each patient underwent two VMAT treatment plans: one optimized by an experienced planner (VMAT-EXP group) and the other designed by a less experienced planner using feasibility dose-volume histogram (FDVH) parameters from PlanIQ (VMAT-FDVH group). Both plans aimed to deliver a prescription dose of 50Gy in 25 fractions to the planning target volume (PTV). Dosimetry parameters for the PTV and organs at risk (OARs) were compared between the two groups. Both the VMAT-EXP and VMAT-FDVH groups met the clinical plan goals for PTV and OARs. VMAT-FDVH demonstrated a PTV coverage and homogeneity comparable to those of VMAT-EXP. Compared to VMAT-EXP plans, VMAT-FDVH plans resulted in a significant reduction in the mean ipsilateral lung dose, with an average decrease of 0.9Gy (8.5Gy vs. 7.6Gy, P < 0.001). The V5Gy and V20Gy of the ipsilateral lung were also reduced by 3.2% and 1.8%, respectively. Minor differences were observed in the heart, contralateral lung, breast, and liver. Personalized objectives derived from the feasibility DVH tool facilitated the generation of acceptable VMAT plans. Less experienced planners achieved lower doses to the ipsilateral lung while maintaining adequate target coverage and homogeneity. These findings suggest the potential for the effective use of VMAT in in patients with left-sided breast cancer following breast-conserving surgery, especially when guided by feasibility DVH parameters.

The Contralateral Lung: An Opportunity for Lung Transplant at a Lower Lung Allocation Score?

The Contralateral Lung: An Opportunity for Lung Transplant at a Lower Lung Allocation Score?

Serial changes of 99mTc- pyrophosphate uptake in patients with hereditary transthyretin amyloid cardiomyopathy treated with tafamidis

Abstract Objective Transthyretin amyloid cardiomyopathy (ATTR-CM) arises from the deposition of amyloid in the heart, resulting in adverse outcomes. Tafamidis has demonstrated potential in slowing disease progression. Our research group, alongside others, has documented cases where decrease in cardiac tracer uptake were observed through bone scintigraphy after tafamidis treatment.[1-8] This study aims to assess the efficacy of Technetium-99m (99mTc)-pyrophosphate (PYP) scintigraphy in longitudinally monitoring tafamidis treatment for hereditary ATTR-CM over an extended follow-up period. Methods We retrospectively analyzed a prospective cohort of hereditary ATTR-CM patients treated with tafamidis (61 mg/day) retrospectively. A control group comprised hereditary ATTR-CM patients who hadn't received eplontersen, inotersen, tafamidis, or patisiran. 99mTc-PYP SPECT/CT scans were conducted at baseline and 1-3 years post-treatment, measuring visual score, planar heart to contralateral lung (H/CL) ratio, and volumetric heart to lung (H/L) ratio. Results Twenty hATTR-CM patients received tafamidis, with the other ten in the control group. After a 2-year follow-up, the tafamidis group experienced a significant decrease in volumetric heart to lung (H/L) ratio (3.817 to 3.011, p &amp;lt; 0.001), while the control group showed no significant change (3.775 to 3.621, p = 0.121)(Figure 1B). Significant decreases in volumetric H/L ratio were noted in the first year of tafamidis treatment (-21.71%), with minimal changes in the subsequent two years (-0.77% in the second year and -2.41% in the third year)(Figure 2B). Conclusion A significant initial reduction in 99mTc-PYP uptake was observed in hereditary ATTR-CM patients during the first year of tafamidis treatment. However, this effect was not sustained in the subsequent two years. Further investigation is warranted to comprehend the long-term efficacy of tafamidis in these patients.Changes in 99mTc-PYP uptake at 2 yearsChanges between 1st, 2nd and 3rd year

Effects of Inc parameter on quality of VMAT radiotherapy plans for right breast cancer based on dosimetric study.

This study aimed to investigate the influence of gantry angle increment (Inc) parameters on the Monaco treatment planning system for volumetric modulated arc therapy (VMAT) in right breast cancer, and to determine the optimal Inc parameters. Twenty-three patients with right breast cancer at the Sir Run Run Shaw Hospital from August 2022 to August 2023 were retrospectively selected. Four VMAT plans were generated for each patient incorporating Inc of 10°, 20° (control group), 30°, and 40°, while the other optimization parameters and constraint functions remained constant. The D98 and conformity index were lower in the Inc30 and Inc40 groups than in the Inc20 group. As Inc increased from 10° to 30°, the irradiated dose to the ipsilateral lung, including the V20, V5, and Dmax, mean dose, gradually increased. There were no statistically significant differences in the irradiated dose to the contralateral breast, contralateral lung, heart, esophagus, and brachial plexus. The number of monitor units and control points decreased with increasing Inc. Smaller Inc values can achieve higher target coverage and lower irradiated dose to the ipsilateral lung, but will reduce delivery efficiency. Considering the plan quality and delivery efficiency, an Inc of 10° or 20° is recommended for right breast cancer VMAT plans.

Use of technetium-99m-pyrophosphate single-photon emission computed tomography/computed tomography in monitoring therapeutic changes of RNA interference therapeutics in patients with hereditary transthyretin amyloid cardiomyopathy

RNA interference therapeutics reduce transthyretin production; however, their effect on hereditary transthyretin amyloid cardiomyopathy (ATTR-CA) remains unclear. We aimed to investigate alterations in technetium-99m (99mTc)-pyrophosphate (PYP) single-photon emission computed tomography/computed tomography (SPECT/CT) outcomes in patients receiving patisiran or vutrisiran. We retrospectively identified individuals with hereditary ATTR-CA who received patisiran or vutrisiran. First and second 99mTc-PYP SPECT/CT data, including visual grading, planar heart to contralateral lung (H/CL) ratio, and volumetric heart to lung (H/L) ratio were assessed. Eight patients with hereditary ATTR-CA were enrolled. Cohort A included four patients who underwent their first 99mTc-PYP SPECT/CT imaging at the initiation of small interfering RNA (siRNA) treatment, while cohort B comprised four patients who had been receiving siRNA treatment before their first 99mTc-PYP SPECT/CT imaging (median duration 1281 days). Overall, there were numerical reductions in planar H/CL ratio (1.7±0.2 to 1.6±0.1, p=0.050) and a significant improvement in volumetric H/L ratio (4.0±0.9 to 3.5±0.4, p=0.035). Although without significance, subgroup analysis showed more pronounced changes in cohort A for both planar H/CL ratio and volumetric H/L ratio (-20.1±12.6% and -17.1±11.4%) compared to cohort B (-3.3±11.2% and -4.3±12.7%). Our results demonstrated a significant decrease in volumetric H/L ratio in hereditary ATTR-CA patients receiving RNA interference therapeutics.

Dosimetric comparison of gamma knife and linear accelerator (VMAT and IMRT) plans of SBRT of Lung tumours

This study evaluates dosimetric differences in Stereotactic Body Radiation Therapy (SBRT) for lung tumors using plans of Gamma Knife, and Volumetric Modulated Arc Therapy (VMAT), Intensity-Modulated Radiation Therapy (IMRT) plans based on Linear Accelerator, aiming to inform the reader of appropriate treatment strategy selection. Ten patients with 23 lung tumor lesions treated with SBRT at Zhongshan Hospital of Dalian University were analyzed. Plans of Gamma Knife, and VMAT, IMRT plans based on Linear Accelerator were created for each lesion, totaling 18 plans per type. Lesions were treated with 30–50 Gy in 5–10 fractions. Dosimetric parameters, including gradient index (GI), heterogeneity index (HI), conformity index (CI), and doses to the plan target volumes (PTVs), the gross tumor volumes (GTVs) and organs at risk (OARs) were compared. Plans of Gamma Knife showed superior HI and GI, higher PTV and GTV doses, and reduced doses to the ipsilateral and contralateral lungs, esophagus, spinal cord, and heart compared to VMAT and IMRT plans (p < 0.05). However, Plans of Gamma Knife required longer delivery times. When comparing VMAT and IMRT plans, VMAT plans had shorter delivery times than IMRT plans, but required more monitor units (MUs). Additionally, IMRT plans delivered a lower mean dose to the ipsilateral lung compared to VMAT plans. Gamma Knife SBRT plans achieves steeper dose falloff and minimizes radiation to normal lung tissue compared to VMAT and IMRT plans, but with longer delivery times. VMAT and IMRT plans displayed similar dose distributions for lung SBRT.

Quantitative computed tomography assessment of pulmonary function and compensation after lobectomy and segmentectomy in lung cancer patients.

The effect of different surgical methods on postoperative lung function in patients with lung cancer is still inconclusive. The main objective of this study was to compare the effects of video-assisted thoracic surgery (VATS) lobectomy and segmentectomy on postoperative pulmonary function and compensatory changes in patients undergoing lung cancer surgery. A total of 120 patients (82 VATS lobectomy, 38 VATS segmentectomy) were assessed for demographic characteristics, baseline pulmonary function, tumor volume, T stage, and histological grade. Postoperative pulmonary function and compensatory changes [percentage of the well-aerated lung (WAL) total (or unilateral) lung volume (LV) (WAL%) and non-operated lung (NOL)] were measured at multiple time points up to 2 years. Logistic regression analysis identified factors associated with WAL% decline after 1 year. Both VATS lobectomy and segmentectomy led to a decrease in pulmonary function, with no significant difference in the extent of decline between the two groups (all P>0.05). Lobectomy triggered a more pronounced compensatory response, characterized by increased ipsilateral NOL volume over time. Segmentectomy induced minimal compensatory changes and had a minimal impact on pulmonary function. Factors associated with decreased pulmonary ventilation after 1 year differed between the lobectomy and segmentectomy groups. In the lobectomy group, a higher preoperative WAL% of ipsilateral NOL [odds ratio (OR) =1.073; 95% confidence interval (CI): 1.017-1.133; P=0.01] was associated with a higher risk of decline in pulmonary function, whereas in the segmentectomy group, the only influencing factor was the preoperative contralateral mean lung density (MLD) (OR =0.932; 95% CI: 0.884-0.984; P=0.01). Both lobectomy and segmentectomy after lung cancer surgery result in a decrease in WAL%, with lobectomy demonstrating a stronger pulmonary compensatory capacity. The application of quantitative computed tomography (CT) has shown significant value in predicting postoperative pulmonary function preservation and compensatory changes, providing strong support for personalized surgical decision-making.

Deep learning-based prediction of the dose-volume histograms for volumetric modulated arc therapy of left-sided breast cancer.

The advancements in artificial intelligence and computational power have made deep learning an attractive tool for radiotherapy treatment planning. Deep learning has the potential to significantly simplify the trial-and-error process involved in inverse planning required by modern treatment techniques such as volumetric modulated arc therapy (VMAT). In this study, we explore the ability of deep learning to predict organ-at-risk (OAR) dose-volume histograms (DVHs) of left-sided breast cancer patients undergoing VMAT treatment based solely on their anatomical characteristics. The predicted DVHs could be used to derive patient-specific dose constraints and dose objectives, streamlining the treatment planning process, standardizing the quality of the plans, and personalizing the treatment planning. This study aimed to develop a deep learning-based framework for the prediction of organ-specific dose-volume histograms (DVH) based on structures delineated for left-sided breast cancer treatment. We used a dataset of 249 left-sided breast cancer patients treated with tangential VMAT fields. We extracted delineated structures and dose distributions for each patient and derived slice-by-slice DVHs for planning target volume (PTV) and organs-at-risk. The patients were divided into training (70%, n=174), validation (10%, n=24), and test (20%, n=51) sets. Collected data were used to train a deep learning model for the prediction of the DVHs based on the delineated structures. The developed deep learning model comprised a modified DenseNet architecture followed by a recurrent neural network. In the independent test set (n=51), the point-wise differences in the slice-by-slice DVHs between the clinical and predicted DVHs were small; the mean squared errors were 3.53, 1.58, 2.28, 3.37, and 1.44 [×10-4] for PTV, heart, ipsilateral lung, contralateral lung, and contralateral breast, respectively. With the derived cumulative DVHs, the mean absolute difference±standard deviation of mean doses between the clinical and the predicted DVH were 0.08± 0.04Gy, 0.24± 0.22Gy, 0.73± 0.46Gy, 0.07± 0.06Gy, and 0.14± 0.14Gy for PTV, heart, ipsilateral lung, contralateral lung, and contralateral breast, respectively. The deep learning-based approach enabled automatic and reliable prediction of the DVH based on delineated structures. The predicted DVHs could potentially serve as patient-specific clinical goals used to aid treatment planning and avoid suboptimal plans or to derive optimization objectives and constraints for automated treatment planning.

Evaluation of Inverse Planned and Forward Planned Intensity Modulated Radiotherapy Techniques in Breast Cancer

Introduction: The objective of this study is to compare the dosimetric parameters of radiation to the whole breast between the two intensity-modulated radiotherapy (IP IMRT) techniques, i.e. Inverse planned IMRT (IP IMRT) and Forward Planned IMRT (FP IMRT) with regard to target coverage (PTV) and irradiation of organs at risk (OAR). Material and Methods: Plain and Contrast enhanced computed tomography (CECT) datasets were created for 41 patients treated with whole breast radiation therapy. CT simulation and treatment is performed using deep inspiratory breath hold technique (DIBH). Radiotherapy treatment Planning is done using Eclipse Treatment Planning System (version 13.7) with a prescription dose of 40 Gy in 15#. The developed treatment plans were subjected to objective comparison of PTV and OARs using dose volume histograms (DVH). Results: IP IMRT plans provided better coverage (99.5% vs 97.6%), comparable though higher maximum dose (Dmax 45.0 VS 44.1 Gy), higher hot spot (PTV105% 49.2 vs 33), lower volumes receiving 20, 25, 30 Gy (V20, V25, V30) for heart, more homogeneous (homogeneity index 0.10 vs. 0.14) and conformal dose distribution (conformity Index 1.0 vs 0.98) compared to FP IMRT. Regarding OAR dosimetry it is observed that FP IMRT showed reduced mean dose to Coronary artery (LADCA), Contralateral Lung (CL), Contralateral breast (CB) along with reduction in low dose region (V5) to all OARs under study. It was also observed that Monitor units used and planning time were lower for FP IMRT. Conclusion: On weighing different dosimetric factors, both the techniques have displayed their own advantages and disadvantages. Choosing a planning technique needs to be customized taking into consideration various factors such as breast topography, size and volumes of breast, availability of expertise planning skills and resources.

Bibliometric and knowledge map analysis of one lung ventilation.

One lung ventilation (OLV) is an essential method of lung isolation to protect the ventilated lung from soiling by the contralateral lung and obtain optimal surgical exposure in thoracic surgery. This study aims to examine the trends and developments in OLV research from 1982 to 2024 through bibliometric analysis. The literature on OLV was systematically searched in the Web of Science Core Collection database for this study. VOSviewer and CiteSpace were utilized to perform comprehensive bibliometric and visual analyses of global publication/trends, countries/institutions, authors/co-cited authors, journals/co-cited journals, co-cited references, and keywords in the field of OLV. A total of 1,682 articles and reviews on OLV research were identified, which showed an overall growing trend from 1982 to 2024. The United States was the leader in this field, accounting for the largest number of publications (n=299). Among all institutions, Yonsei University had the largest number of publications (n=23), but National Taiwan University Hospital had the highest number of cited publications (n=876). The papers related to OLV were mainly published in Journal of Cardiothoracic and Vascular Anesthesia (n=147) and the most productive author was Cheng YJ (n=15). After keywords analysis, "infants", "dexmedetomidine", "inflammation", and "airway management" were newly emergent research hotspots. Through bibliometric and visualization methods, we undertook a comprehensive analysis in the field of OLV. The United States maintained a top position in this field, the emerging hotspots of OLV changed from basic research to clinical research and the further innovation of OLV management. This study provides new ideas for scholars in their future works.

COMPARATIVE RADIATION DOSIMETRY OF WHOLE BREAST RADIOTHERAPY USING IMRT AND VMAT TECHNIQUES IN LEFT SIDED BREAST CANCER PATIENTS AFTER BREAST CONSERVING SURGERY

Background:The radiotherapy of left sided breast cancers is mandatory and integral part of treatment and challenging because of surrounding critical structures posing increased risk of complications. The main objective of this study was to quantify doses toorgan at risk(OARs) including left lung, heart, contralateral breast, spinal cord, and planning target volume (PTV) using different radiation techniques like Intensity modulated radiation therapy (IMRT)&amp;volumetric modulated arc therapy (VMAT) and comparison of radiation dosimetry. Methods: A prospective study of 30 patients of left sided breast cancer who had undergone Breast Conservative Surgery (BCS) and chemotherapy was done for adjuvant radiation. For every patient radiation planning was done by two different techniques IMRT and VMAT. Then the comparison of radiation dosimetry parameters was done for all the techniques including the parameters like PTV coverage, doses to OAR like heart, left lung, contralateral breast and spinal cord and head of humerus. The Homogenity Index (HI) were calculated. Result: The Mean age of the patient was 46.7 years. When comparing the doses delivered in IMRT and VMAT Technique for left sided breast cancer post breast conservation surgery there was significant difference in PTV Breast and axilla V95 Gy. It was 96.2±1.9% (IMRT) vs 94.8±1.71% (VMAT), (p=0.004). However significant sparing of Organs at Risk was seen. With ipsilateral lung dose mean V5 Gy was 77.86± 9.68% (IMRT) v/s 83.04± 9.86 % (VMAT), (p=0.0446). Also mean V30 Gy was 14.6±4.82% with IMRT vs 16.54±5.86% with VMAT, (p=0.0169). Heart mean dose was 8.8±1.49 Gy with IMRT and 10.98±3.7 Gy with VMAT, (p=0.0227). Further V30 Gy for Heart was 4.61±3.8% with IMRT and 6.72±4.0% with VMAT, (p=0.0132).No significant difference was seen with IMRT and VMAT technique for contralateral lung, contralateral breast and spinal cord. Conclusion: In treatment of patients with radiation with left breast cancer patients post BCS using IMRT and VMAT technique it is seen significant dose reduction with IMRT Technique for ipsilateral lung and Heart as compared to VMAT technique. Significant V95 coverage for PTV Breast and axilla with IMRT as compared to VMAT. Hence in our Study IMRT technique was found to be superior for better sparing of Organ at risk and better PTV coverage.

A novel x-Ray and γ-Ray combination strategy for radiotherapy after breast-conserving surgery in patients with right breast cancer.

Radiotherapy is a primary therapeutic approach for breast cancer following breast-conserving surgery. The TaiChiB dual-modality radiotherapy system combining X-ray and focused γ-ray, offers a new approach to reduce the radiation dose of organs at risk (OARs) and has the potential to mitigate the adverse effects of radiotherapy. Currently, there are few studies on the dosimetric characteristics of the TaiChiB dual-modality system for actual treatment plans for specific diseases. The purpose of this work is to study the dosimetric advantages of dual-modal systems for right breast patients after breast-conserving surgery. Treatment plans for 20 patients with right breast cancer were generated for a linear accelerator (LINAC) based system and the TaiChiB dual-modality system, respectively. Volumetric modulated arc therapy plans with simultaneous integrated boost (VMAT-SIB) were made for the LINAC. Focused γ-ray was used to deliver the boost dose with the dual-modality system. The dosimetric parameters of the target and OARs were evaluated and compared between the treatment plans generated for the two systems. The TaiChiB dual-modality plans exhibit a higher conformal index (CI) and lower gradient index (GI) for the PGTV and PTV compared with the LINAC-based VMAT-SIB plans. Compared to VMAT-SIB plans, the PTV Dmax, PTV Dmean, PTV V110, PGTV Dmax, and PGTV Dmean of the TaiChiB dual-modality plans are significantly lower. Meanwhile, the dose to OARs, such as the Dmean of the heart, the V5 of liver, the Dmean of ipsilateral lung, the V30 of ipsilateral lung, the V20 of ipsilateral lung, the V5 of ipsilateral lung, the Dmean of contralateral lung, Dmax of contralateral breast and the Dmean of contralateral breast are significantly reduced. Our study demonstrates the dosimetric advantages of the novel TaiChiB dual-modality radiotherapy system for the treatment of right-sided breast cancer. Overall, for the TaiChiB dual-modality radiotherapy system, the radiation dose outside the target region decreases rapidly, thereby minimizing radiation exposure to neighboring organs and ensuring the conformity of the target area. Our research confirms the potential of the TaiChiB dual-modality system for future radiotherapy.

Immunotherapy and PD-L1 Tumor Expression in Moroccan Non-Small Cell Lung Cancer Patients with Various Metastasis.

The question of whether tumor expression of PD-L1 and the presence of distant metastasis could influence the efficacy of immunotherapy represents a major challenge and needs to be further elucidated. The aim of this study is to evaluate the predictive significance of tumor expression of PD-L1 as well as the number and site of metastasis in non-small cell lung cancer (NSCLC) among Moroccan patients treated with immunotherapy. Between January 2019 and February 2023, we recruited Moroccan patients with metastatic NSCLC. All were treated with immunotherapy, either as monotherapy or in combination with chemotherapy. Immunohistochemistry was used to assess PD-L1 (clone 22C3) and ALK (clone D5F3) status. EGFR status was established by qPCR. Tumor PD-L1 expression was classified into 2 levels: TPS <1% (negative expression) and TPS ≥1% (positive expression). Statistical analysis was performed using SPSS Statistics V.21 software. The median age of patients (N=40) was 67 years (39- 92 years) and the sex ratio was 9. Disease dissemination revealed that 22.5% (N=9) of patients had a metastatic burden ≥ 3 (MB≥3). As for the sites of metastasis, the results showed that 20% (N=8), 10% (N=4), 42.5% (N=17), 22.5% (N=9), 27.5% (N=11), 45% (N=18) and 27.5% (N=11) of patients had developed lymph node, liver, bone, brain, pleural, contralateral lung and adrenal metastasis respectively. Positive PD-L1 expression was significantly associated with shorter overall survival (OS = 17.19 vs. 28.85 months, p=0.01). High metastatic burden (MB ≥ 3) was associated with lower objective response rate (ORR), shorter progression-free survival (PFS), and reduced OS, respectively (ORR = 0 vs. 58.06%, p=0.002; PFS = 10.23 vs. 25.27 months, p=0.001; and OS = 11.60 vs. 27.91 months, p=0.003). Only the presence of osseous metastasis was significantly associated with lower ORR, shorter PFS, and OS compared to other metastatic locations (ORR = 5.88 vs. 73.9%, p=0.000; PFS = 10.72 vs. 31.33 months, p=0.000; and OS = 11.39 vs. 36.17 months, p=0.000). Finally, the presence of hepatic metastasis was significantly associated with shorter PFS (10.75 months) compared to those without hepatic metastasis (22.53 months) (p=0.046). Finally, the results of the multivariate analysis revealed that the presence of bone metastasis was strongly correlated with a significant decrease in progression-free survival (p=0.001) as well as overall survival (p=0.002). Our results suggest that tumor expression of PD-L1 and metastatic burden should play a significant role in predicting the response to immunotherapy. Furthermore, it is important to note that the presence of osseous and hepatic metastasis could negatively influence the clinical outcomes of immunotherapy.