First-Year Experience of IMRT/SBRT Treatments Using a Novel Biology-Guided Radiation Therapy System

PURPOSE/OBJECTIVE(S)

This study presents the first-year experience of treating patients using intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) with the X1 system, the first biology-guided radiation therapy (BgRT) machine installed in a clinical setting.

MATERIALS/METHODS

A total of 78 patients underwent IMRT and SBRT treatments on the X1 system from May 2021 to May 2022. Clinical and technical data, such as treatment sites, number of pre-treatments kVCT scans, beam on time, patient setup time, imaging time per kVCT, and couch shifts after kVCT match, were collected and analyzed. Additionally, daily machine output stability, patient-specific quality assurance (QA) results, machine uptime, and user survey were also documented and reported.

RESULTS

The most commonly treated site was the head and neck (63%), followed by the pelvis (23%), thorax (6%), and abdomen (8%). All treatments, except for 5 pelvis patients (6%) who received SBRT treatments for bony metastases, were conventionally fractionated IMRT (CF IMRT). The average number of kVCT scans per fraction is 1.2 ± 0.5 for all treatments. The average beam on time in minutes was 9.2 ± 3.5 for all treatments, 8.4 ± 2.4 for head and neck, 6.7 ± 1.3 for thorax, 10.3 ± 1.6 for abdomen, 11.6 ± 5.1 for CF IMRT pelvis, and 10.8 ± 5.3 for SBRT pelvis. The average patient setup time and imaging time per kVCT was 4.8 ± 2.6 minutes and 4.6 ± 1.5 minutes, respectively. The average couch corrections based on kVCT images were 0.4 ± 4.4 mm, 1.0 ± 4.5 mm, and 1.3 ± 4.3 mm along the x, y, and z direction, respectively; the average couch rotation corrections were 0.1 ± 0.9° for pitch, 0.0 ± 0.9° for roll, and 0.2 ± 1.2° for yaw. The daily machine output was 0.4 ± 1.2% from the baseline. The patient QA had a gamma passing rate of 97.4 ± 2.8%. The machine uptime was 92% of the total treatment time. The kVCT image quality and daily QA process received the highest level of satisfaction, while the treatment workflow for therapists received the lowest level of satisfaction (table 1).

CONCLUSION

At one year after the installation of the X1 system, this study reports successful treatment of 78 patients using IMRT/ SBRT. With the recent FDA clearance of BgRT, our institution is preparing to treat patients using PET-guidance via a new product release, which should address deficiencies in the current IGRT workflow.

Fixed-Field IMRT for Cervix Carcinoma Patients on an MR-LINAC Platform: Dosimetric Feasibility and Challenges

PURPOSE/OBJECTIVE(S)

To investigate the impact of MR-LINAC performance characteristics and inverse planning implementation on the feasibility of fixed-field IMRT for cervix carcinoma patients by benchmarking MR-LINAC plans against clinically used VMAT plans in a single institution study and multi-institutional treatment planning challenge.

MATERIALS/METHODS

For 10 cervix cancer patients who had previously received Linac-based VMAT, new treatment plans were optimized for MR-LINAC IMRT using 6X FFF fixed fields with maximum available field size of 27.4 x 24.1 cm2. Dose optimization was performed on the clinically used planning CT and structure set. Prescribed dose was 48.6 Gy in 27 fractions for all patients with 6 patients receiving an additional integrated boost for a total of 58.05 Gy to involved nodes. Constraints were based on our institutional protocol as per Table 1. IMRT delivery time was limited to 20 min. Original clinically used VMAT plans were generated on Eclipse (Varian Medical System) using 3 to 4 arcs. For the multi-institutional planning challenge, the data set from a single patient was anonymized and shared to participants. Participants used a single MR-based Linac planning platform to generate a plan based on our institutional constraints, with maximum treatment time limited to 20 min. For all analyses, a paired samples t-test was used to compare the significance defined at p < 0.05.

RESULTS

For MR-LINAC plans, the mean number of fields used was 23, mean number of segments 229, and the average estimated treatment delivery time was 17.3 minutes. MR-LINAC plans showed a significantly higher heterogeneity and dose to organs at risk compared to VMAT plans (Table 1). For the planning challenge, a total of 30 participants registered interest. Of this, seven plans were submitted to the challenge. On average, participants generated a plan that would be acceptable based on our institutional constraints (Table 1). However, the volumetric dose to bowel and pelvic bones were higher on MR-LINAC plans compared to the reference VMAT plan.

CONCLUSION

MR-LINAC fixed-field IMRT for cervix cancer patients is feasible but system constraints and optimization implementation result in greater dose heterogeneity and worse organ-at-risk sparing compared to Linac based VMAT. Further research is needed to determine if potential reduction of treatment margins, allowed by better MRI soft-tissue visualization, will result in MR-LINAC IMRT superior to Linac VMAT.

Imaging Performance of the PET Scan on a Novel Ring Gantry-Based PET/CT Linear Accelerator System in the First-in-Human Study of Biology-Guided Radiotherapy

PURPOSE/OBJECTIVE(S)

Biology-guided radiotherapy (BgRT) is a novel tracked dose delivery modality using real-time positron emission tomography (PET) to guide radiotherapy beamlets. The present study was performed with sequential cohorts of participants to evaluate the performance and safety of BgRT. Primary endpoints were previously reported. We hereby report on one of the secondary endpoints assessing a novel treatment planning machine with integrated dual kVCT/PET imaging ("novel device") performance in comparison to a third-party diagnostic PET/CT scan.

MATERIALS/METHODS

This single-arm, open-label, prospective study included participants with at least 1 FDG-avid targetable primary or metastatic tumor (≥2cm and ≤5cm) in the lung or bone. PET imaging data were collected on the novel device and on a third-party diagnostic PET/CT performed in sequence once at the planning timepoint in Cohort I, and immediately before the last fraction among patients undergoing stereotactic radiotherapy in Cohort II. Three central read radiation oncologists (CRRO) provided an interpretation of the novel device PET scans which were compared to an agreement standard based on 3 central radiologists' review of the paired diagnostic PET/CT scan. Positive percent agreement for localization of the target tumor within the biology-tracking zone (BTZ) was the key metric because it reflects whether advancing patients to subsequent steps in the BgRT workflow based on the novel device's imaging was ultimately appropriate.

RESULTS

In Cohort 1, 6 image comparisons were performed. The positive (%) agreement for the aggregate radiation oncologist review was 100% (5/5), reflecting that in all 5 cases where the aggregate radiation oncologists deemed the tumor to fall within the BTZ based upon the novel device PET images, the central radiologists came to the same conclusion upon review of the paired diagnostic PET/CT images. The overall (%) agreement for the aggregate radiation oncologist review was 83.3% (5/6): localization was not established on the novel device in 1 case, even though it was established on the diagnostic PET/CT. This would not pose risk in real world practice as BgRT candidacy would be aborted for tumors not visible on the novel device. In Cohort II, among the 7 image comparisons, there was 100% positive percent agreement between the aggregate CRRO and the agreement standard as the localization criteria was met in both scans for all 7 patients. This was concordant with a 100% overall percent agreement.

CONCLUSION

This investigation demonstrated a 100% positive percent agreement between central review of this novel device images by radiation oncologists and central review of the accompanying third-party PET/CT images by radiologists. There were no cases where a positive localization by the aggregate CRRO was not confirmed by the third-party PET/CT standard, providing evidence against the likelihood of falsely positive localizations on the novel device that would inappropriately advance patients in the workflow.

Workflow Considerations for Biology-Guided Radiotherapy (BgRT) Implementation

PURPOSE/OBJECTIVE(S)

Biology-guided radiotherapy (BgRT) is a novel platform that combines real-time PET imaging with a 6MV Linac to target tumors. The performance and safety of BgRT was assessed in the BIOGUIDE-X clinical trial. This study aims to report on the BgRT workflow steps and assess the time required for each step of the BgRT process during this trial.

MATERIALS/METHODS

A total of nine patients were enrolled in the second Cohort of the BIOGUIDE-X study which included patients treated with stereotactic body radiotherapy (SBRT) for lung tumors (5) and bone tumors (4). The pre-treatment BgRT workflow includes CT simulation, contouring, imaging-only (BgRT Modeling) PET acquisition, BgRT planning, patient specific QA and plan approval. The imaging-only PET acquisition on the X1 collects a representative PET volumetric 3D image and is an input to develop the BgRT treatment plan. The steps during the BgRT delivery session are kVCT localization, PET pre-scan, PET evaluation and BgRT delivery. The PET PreScan is a 1-pass short-duration PET acquisition that is used to confirm that the PET biodistribution on the day of treatment is consistent with that of the imaging-only PET. During BIOGUIDE-X, the BgRT delivery step was replaced by a 4-pass long-PET acquisition that was used to emulate the expected BgRT dose distribution without turning the beam on. To assess BgRT workflow, times from 18F-FDG injection to image-only PET acquisition, 18F-FDG injection to PET pre-scan, Pre-scan to PET evaluation, and PET evaluation to BgRT delivery (long PET acquisition) were recorded.

RESULTS

Time between the 18F-FDG injection and the X1 imaging-only PET scan was 84 ± 19 minutes which includes time for 18F-FDG update. Average time to perform imaging-only PET scan was 26 ± 4 minutes. During the BgRT 'delivery' session, the mean time between the kVCT acquisition and PET pre-scan acquisition was 7 ± 3 minutes. The mean time to acquire a 1-pass PET pre-scan was 6 ± 1 then followed by 6 ± 1 minutes for the PET pre-scan dose calculation to estimate the BgRT doses that it would have delivered for this fraction. On average, the PET reconstruction, the PET signal localization verification and the evaluation of safety metrics took 11 ± 4 minutes. The mean time for BgRT 'delivery' was 27 ± 5 minutes based on the 4-pass long PET acquisition. Time from the start of the BgRT session to the end of the BgRT 'delivery' with this version of the investigative product release was 65 ± 9 minutes.

CONCLUSION

The new processes introduced by the BgRT technology were evaluated and found clinically feasible. Improvements are being undertaken to shorten the time required for each step and to increase patient comfort ahead of BgRT clinical implementation.

Predicting Local Control with Dosimetric Parameters in Patients Receiving Individualized Stereotactic Ablative Radiotherapy for Lung Tumors

PURPOSE/OBJECTIVE(S)

Stereotactic ablative radiotherapy (SABR) is an effective treatment option for lung tumors. The individualized lung tumor SABR (iSABR) trial was a phase II single-arm study that personalized lung tumor SABR dose and fractionation based on tumor size, location, and histology with very low rates of local recurrence (LR). A secondary analysis of this trial was conducted to assess for potential dosimetric predictors of LR, in order to help guide future clinical treatment planning.

MATERIALS/METHODS

From 2011 to 2018, local, regional and distant recurrence data were prospectively collected from 204 patients (261 lung SABR treatments) enrolled in a prospective trial. Baseline characteristics and treatment details were evaluated. Dosimetric and treatment plan parameters were evaluated for their potential to predict LR, using logistic regression and chi-squared analyses.

RESULTS

The majority of treated tumors were peripheral (71%, vs 29% central), primary lesions (76%, versus 24% metastatic), and of adenocarcinoma histology (67%, versus 13% squamous cell carcinoma and 19% other). The median follow-up was 24 months (range 2-95). Twenty-seven (10.3%) LRs occurred, with a median time to LR of 15 months (range 6-81 months). There were no significant associations between the overall cohort and the dosimetric parameters. However, for the multi-fraction cohort, an increased proportion of the PTV receiving 110% and 115% of the prescription dose were associated with lower LR (p = 0.01 and p = 0.01 respectively). Specifically for the 50 Gy in 4 fraction cohort, an increased D1cc, D0.03cc, as well as the proportion of the PTV receiving 110%, 115%, and 120% of the prescription dose were associated with lower LR (p < 0.001, p = 0.001, p = 0.003, p < 0.001, p = 0.004, respectively). There was no association of LR with prescription dose expressed as biologically effective dose using an alpha/beta of 10 Gy (BED10), D99%, or single- versus multi-fraction regimens.

CONCLUSION

SABR for lung tumors using the individualized protocol on this trial showed excellent LR rates. We identified dosimetric parameters that were associated with LR, including V110% and V115% within the multi-fraction cohort, as well as the 50 Gy in 4 fraction cohort the D1cc, D0.03cc, and proportions of the PTV receiving 110%, 115%, and 120% of the prescription dose in the 50 Gy in 4 fraction cohort. Optimal thresholds for these parameters will be identified in further analyses. There did not appear to be an association with LR and BED10, D99%, or comparing single- vs multi-fraction regimens.

Prospective Clinical Adoption of Artificial Intelligence for Organ Contouring in Head and Neck Radiation Treatment Planning

PURPOSE/OBJECTIVE(S)

Patients that undergo head and neck (H&N) radiation therapy (RT) require laborious delineation of organs-at-risk (OARs) on computed tomography (CT) scans in a treatment planning system (TPS) to minimize radiation to normal tissue. This task can be completed rapidly and accurately with recently developed artificial intelligence-based semantic segmentation models. The current study aims to deploy and evaluate a strategy for improving clinical practice with this technology.

MATERIALS/METHODS

Deep learning models were trained and tested with CT scans and OAR contours from previous H&N RT cases at our clinic. Two medical physicists vetted the models and selected a 2.5D U-Net for further implementation. The model was embedded in a dedicated server at the hospital, programmed to read H&N CT scans staged for import into the TPS, generate auto-contours, and write them into a TPS-compatible format made available alongside the scan. In the pilot implementation, the auto-contouring service was utilized for more than 60 cases, prospectively. The auto-contours were quantitatively evaluated against the treatment-approved contours to determine how much modification was performed by the clinical team.

RESULTS

The 2.5D U-Net selected for clinical integration segments 21 OARs in less than 3 minutes per scan. Across all the prospective cases, the mean Dice score and mean 95th percentile Hausdorff distance (mm) between the auto-contour and treatment-approved contour for each of the 21 OARs were as follows, respectively: brainstem (0.93, 1.94), optic chiasm (0.70, 2.96), left cochlea (0.69, 2.37), right cochlea (0.68, 2.44), esophagus (0.88, 2.46), left globe (0.93, 1.50), right globe (0.93, 1.63), glottis (0.91, 2.13), larynx (0.93, 2.76), mandible (0.90, 4.86), left optic nerve (0.78, 1.64), right optic nerve (0.82, 1.65), oral cavity (0.86, 8.46), left parotid gland (0.91, 2.78), right parotid gland (0.91, 2.39), pharynx (0.85, 2.39), spinal cord (0.87, 2.27), left submandibular gland (0.85, 3.46), right submandibular gland (0.83, 3.69), left temporal lobe (0.94, 2.20), and right temporal lobe (0.95, 2.09). The auto-contours for the optic chiasm, optic nerves, cochleas, and submandibular glands differed substantially from the final contours, a finding corroborated by the clinical team; the rest were clinically acceptable with minor or no edits necessary.

CONCLUSION

The proposed strategy provides a sophisticated starting point for treatment planning that has garnered overall favorable feedback from the participating radiation oncologists and dosimetrists. Consequently, the technique is being extended to other treatment sites.

Comparison of Plan Quality Metrics after Left Anterior Descending Coronary Artery Sparing in VMAT Esophageal Radiotherapy

PURPOSE/OBJECTIVE(S)

Cardiotoxicity is a significant late effect of esophageal radiotherapy (RT). Mean heart dose has been implicated with major adverse cardiac events (MACE) and emerging evidence increases MACE association with left anterior descending (LAD) coronary artery specific dose. This retrospective planning study investigates the dosimetric impact of including the LAD as an OAR-sparing objective for VMAT-based plan optimization in patients previously treated for esophageal cancers.

MATERIALS/METHODS

A retrospective cohort was identified of patients who underwent neoadjuvant RT for esophageal cancers between 2017-2020 without intentional LAD sparing. Treatment planning was performed using Eclipse™ treatment planning system. Doses were calculated using Acuros® XB algorithm or anisotropic analytical algorithm with a 2-2.5mm calculation grid. For each patient, the LAD was delineated and the treated VMAT plan was re-optimized to reduce the dose to the LAD receiving 15 Gy to less than 10%, when possible. Re-plans were performed such that 95% of the PTV received the prescription dose. Institutional constraints were used to minimize the dose to the heart, lung, and spinal cord (Table 1). A paired t-test was used to compare the dose between the original VMAT plan used for treatment (Esophagus Original) against those re-optimized (Esophagus + LAD), with significance of p<0.05.

RESULTS

A total of 19 patients were identified. Of those treated, 12 of 19 original plans (63%) exceeded the LAD constraint (V15<10%) with a mean V15 Gy of 47.1%. Plan re-optimization accounting for the LAD allowed for 66.7% (9/12) of cases to meet LAD V15 constraints. Aside from increased sparing of the mean heart dose, there were no statistically significant impacts on target coverage and OAR doses otherwise, including to that of the lung and spinal cord (Table 1).

CONCLUSION

Accounting for LAD dose in treatment planning may help reduce future MACE risks. LAD dose can be significantly reduced without compromising PTV coverage or having significant effects on other OAR dose sparing.

Mitigation of IMRT/SBRT Treatment Planning Errors on the First Biology-Guided Radiotherapy System Using FMEA within Six Sigma Framework

PURPOSE/OBJECTIVE(S)

Utilize the Six Sigma methodology and Failure Mode and Effect Analysis (FMEA) to prevent and mitigate errors in IMRT/SBRT treatment planning with the first clinical installation of biology-guided radiotherapy (BgRT) system.

MATERIALS/METHODS

The Six Sigma approach consisted of five phases: Define-Measure-Analyze-Improve-Control. The Define-Measure-Analyze phases consisted of process mapping and an FMEA of the IMRT/SBRT treatment planning process on the BgRT system. The multidisciplinary team outlined the workflow process and identified the failure modes associated with the plan check items using AAPM TG-100 recommendations. Items with the highest average risk priority numbers (RPN) and Severity ≥7 were prioritized for automation using the treatment planning system scripting API (ESAPI). The Improve phase consisted of developing ESAPI scripts prior to the launch of the BgRT system to improve efficiency and safety. In the Control phase, the FMEA ranking was re-evaluated 1-year post-clinical launch.

RESULTS

Overall, 100 plan check items were identified where the RPN values ranged from 10.2 to 429.0. Fifty of these items (50%) were suitable for automation within ESAPI. Of the 10 highest-risk items (Table 1), 8 were suitable for automation. Based on the results of the FMEA, two scripts were developed: Planning Assistant used by the planner during preparation for planning and the Automated Plan Check used by the planner and the plan checker during plan preparation for treatment. At 1-year post-clinical launch, the scripts were used for 80 patients successfully treated in 1747 fractions. During this period only 3 errors were reported: omitted bolus during treatment, nomenclature error in the BgRT system plan prescription, and dose tracking plan not approved following physics plan check. The average RPN pre-scripts was 138.0 compared to the average post-scripts RPN of 47.8 (p < 0.05) signifying a safer process.

CONCLUSION

Implementing new technology into the clinic can be an error-prone process where the likelihood of errors increases with increasing pressure to implement the technology quickly. To limit errors in the clinical implementation of the first BgRT system, the Six Sigma methodology was utilized to identify failure modes, establish quality control checks, and re-evaluate these checks 1-year post-clinical launch.

Baseline Quality-of-Life of Caregivers of Patients With Heart Failure Prior to Advanced Therapies: Findings From the Sustaining Quality of Life of the Aged: Transplant or Mechanical Support (SUSTAIN-IT) Study

BACKGROUND

We compared health-related quality of life (HRQOL), depressive symptoms, anxiety, and burden in caregivers of older patients with heart failure based on the intended therapy goal of the patient: awaiting heart transplantation (HT) with or without mechanical circulatory support (MCS) or prior to long-term MCS; and we identified factors associated with HRQOL.

METHODS

Caregivers (n = 281) recruited from 13 HT and MCS programs in the United States completed measures of HRQOL (EQ-5D-3L), depressive symptoms (PHQ-8), anxiety (STAI-state), and burden (Oberst Caregiving Burden Scale). Analyses included ANOVA, Kruskal-Wallis tests, χ² tests, and linear regression.

RESULTS

The majority of caregivers were female, white spouses with ≤ 2 comorbidities, median [Q1,Q3] age = 62 [57.8, 67.0] years. Caregivers (HT with MCS = 87, HT without MCS = 98, long-term MCS = 96) reported similarly high baseline HRQOL (EQ-5D-3L visual analog scale median score = 90; P = 0.67 for all groups) and low levels of depressive symptoms. STAI-state median scores were higher in the long-term MCS group vs the HT groups with and without MCS, (38 vs 32 vs 31; P < 0.001), respectively. Burden (task: time spent/difficulty) differed significantly among groups. Caregiver factors (number of comorbidities, diabetes and higher anxiety levels) were significantly associated with worse caregiver HRQOL, R² = 26%.

CONCLUSIONS

Recognizing caregiver-specific factors, including comorbidities and anxiety, associated with the HRQOL of caregivers of these older patients with advanced HF may guide support strategies.

Measuring the arterial phase of the right coronary artery in the patients suspected of coronary artery disease: a dual study by dynamic angiography and deep learning program

Funding Acknowledgements

Type of funding sources: None.

Background. In the diagnosis of coronary artery disease (CAD), coronary angiography (CA) plays a crucial role in determining the location and severity of the stenosis, the anatomical aspect of a lesion. It does not accurately reflect the flow dynamics in the coronary artery. This study aimed to evaluate the coronary flow abnormalities based on our new angiographic technique and Deep Learning (DL) program in patients suspected of CAD.

Methods. We randomly selected patients who were admitted with suspected CAD. All patients underwent our new technique of CA. After the index coronary artery was filled completely with contrast, we stopped the injection. At that time, the blood in white color flew in. The flow characteristics, the shape of the tip, borders, and direction could be clearly observed above a black background of the contrast. In this study, we measured the arterial phase (AP) from the beginning when the blood moved in until the end when all contrasts in black color washed out of the distal vasculature. In the DL protocol, the U-Net model combined with Dense-Net-121 and a binary image classification model are used to predict the beginning and ending frame. To obtain the best image for the DL program, we analyzed only the flow of the right coronary artery (RCA).

Results. 81 patients were enrolled. In patients with normal coronary angiography, the mean AP was 1.86s (27.4 +/- 5.4 frames). In patients with one significant lesion, the mean AP value was 2.35s (35.3 +/- 7.7 frames). The mean difference of the AP between the two groups was 0.49s (95% confidence interval: 0.295 to 0.694). This difference is statistically significant. Our DL has the mean root square error in predicting the AP was 0.34s.

Conclusion. In patients with CAD, the prolonged arterial phase could be accurately estimated using the DL program, reflecting the slow circulation of highly oxygenated blood. It could be used as a marker of coronary perfusion in future studies.

Using Ligand-Accelerated Catalysis to Repurpose Fluorogenic Reactions for Platinum or Copper

The development of a fluorescent probe for a specific metal has required exquisite design, synthesis, and optimization of fluorogenic molecules endowed with chelating moieties with heteroatoms. These probes are generally chelation- or reactivity-based. Catalysis-based fluorescent probes have the potential to be more sensitive; however, catalytic methods with a biocompatible fluorescence turn-on switch are rare. Here, we have exploited ligand-accelerated metal catalysis to repurpose known fluorescent probes for different metals, a new approach in probe development. We used the cleavage of allylic and propargylic ethers as platforms that were previously designed for palladium. After a single experiment that combinatorially examined >800 reactions with two variables (metal and ligand) for each ether, we discovered a platinum- or copper-selective method with the ligand effect of specific phosphines. Both metal-ligand systems were previously unknown and afforded strong signals owing to catalytic turnover. The fluorometric technologies were applied to geological, pharmaceutical, serum, and live cell samples and were used to discover that platinum accumulates in lysosomes in cisplatin-resistant cells in a manner that appears to be independent of copper distribution. The use of ligand-accelerated catalysis may present a new blueprint for engineering metal selectivity in probe development.

Dynamic Alteration of Neutrophil-to-Lymphocyte Ratio over Treatment Trajectory is Associated with Survival in Esophageal Adenocarcinoma

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been identified as a biomarker for multiple malignancies. There is emerging evidence that implicates neutrophils in cancer progression. Alterations of neutrophil counts and NLR during treatment may reflect a change in oncologic outcome that is more important than baseline values. The aim of this study is to investigate the prognostic role of NLR changes during the treatment trajectory of patients with esophageal adenocarcinoma.

PATIENTS AND METHODS

NLR values of patients with esophageal adenocarcinoma who underwent surgery between 2005 and 2016 were measured at baseline and in the late postoperative period. Primary outcomes were overall survival (OS) and disease-free survival (DFS). The secondary outcome was pathological response to neoadjuvant chemotherapy.

RESULTS

330 patients were included; mean age was 65.6 years, and 82% were male. Most patients had cT3 (74.8%), cN-positive (59.7%) disease. Two-thirds (65.2%) received neoadjuvant chemotherapy. The independent predictors of OS were pathological N-stage, size of primary tumor, and delta NLR (late - baseline NLR). Patients with persistently elevated NLR did worse than those with decreasing NLR trends between baseline and postoperative time points (3-year OS 43.4% versus 71.3%, p < 0.0001, 3-year DFS 29.7% versus 61.9%, p < 0.0001). High baseline and postoperative NLR were associated with significantly worse OS and DFS. Patients with complete pathological response had lower mean baseline NLR.

CONCLUSION

Dynamic changes in NLR during treatment are associated with survival and may be more informative than static baseline values.

Lactose drives Enterococcus expansion to promote graft-versus-host disease

Disruption of intestinal microbial communities appears to underlie many human illnesses, but the mechanisms that promote this dysbiosis and its adverse consequences are poorly understood. In patients who received allogeneic hematopoietic cell transplantation (allo-HCT), we describe a high incidence of enterococcal expansion, which was associated with graft-versus-host disease (GVHD) and mortality. We found that Enterococcus also expands in the mouse gastrointestinal tract after allo-HCT and exacerbates disease severity in gnotobiotic models. Enterococcus growth is dependent on the disaccharide lactose, and dietary lactose depletion attenuates Enterococcus outgrowth and reduces the severity of GVHD in mice. Allo-HCT patients carrying lactose-nonabsorber genotypes showed compromised clearance of postantibiotic Enterococcus domination. We report lactose as a common nutrient that drives expansion of a commensal bacterium that exacerbates an intestinal and systemic inflammatory disease.

Discoveries, target identifications, and biological applications of natural products that inhibit splicing factor 3B subunit 1

Covering: 1992 to 2015The natural products FR901464, pladienolide, and herboxidiene were discovered as activators of reporter gene systems. Unexpectedly, these compounds target neither transcription nor translation; rather, they target splicing factor 3B subunit 1 of the spliceosome, causing changes in splicing patterns. All of them showed anticancer activity in a low nanomolar range. Since their discovery, these molecules have been used in a variety of biological applications.