8 research outputs found
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The Impact of Pelvic Nodal Radiotherapy on Hematologic Toxicity: A Systematic Review with Focus on Leukopenia, Lymphopenia and Future Perspectives in Prostate Cancer Treatment
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•Pelvic nodal radiotherapy contributes to hemato-toxicity development•Pelvic bone marrow stem cells are highly radiosensitive•Bone marrow sparing techniques can reduce hemato-toxicity•Radiation-induced lymphopenia can lead to dismal prognosis in cancer patients•Bone marrow should be regarded as an essential organ-at-risk in this setting
Hematologic toxicity (HT), particularly leukopenia, is a common side-effect of oncologic treatments for pelvic malignancies. Pelvic nodal radiotherapy (PNRT) has been associated with HT development mainly through incidental bone marrow (BM) irradiation; however, several questions remain about the clinical impact of radiotherapy-related HT. Herein, we perform a systematic review of the available evidence on PNRT and HT.
A comprehensive systematic literature search was performed through EMBASE. Hand searching and clinicaltrials.gov were also used.
While BM-related dose-volume parameters and BM-sparing techniques have been more thoroughly investigated in pelvic malignancies such as cervical, anal, and rectal cancers, the importance of BM as an organ-at-risk has received less attention in prostate cancer treatment.
We examined the available evidence regarding the impact of PNRT on HT, with a focus on prostate cancer treatment. We suggest that BM should be regarded as an organ-at-risk for patients undergoing PNRT
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Adaptive versus non-adaptive MRI-guided radiation treatments for pancreatic cancer: A dosimetric study
336 Background: Combination MRI and radiation therapy systems enable magnetic resonance image guided radiation therapy (MR-IGRT). MR-IGRT allows clear visualization of the target and organs at risk (OARs) allowing for dose adaptation. Using adaptive MR-IGRT with Cobalt-60 for stereotactic body radiation therapy (SBRT) in locally advanced pancreatic cancer (LAPC), we hypothesized that MR-IGRT would improve dose to pancreatic tumor without increasing doses to OARs. Methods: Ten LAPC patients received five fraction SBRT with a total dose of 33-40 Gy. For each fraction, the original plan dose was compared to the dose that would be delivered if the original radiotherapy plan was applied to the anatomy that day (non-adaptive). An adaptive plan was then created for each fraction. The plan was re-optimized based on the anatomy as seen on the daily MRI and re-normalized so the volume of the PTV receiving 100% of the prescription (PTV100) would be 90%. Both the non-adaptive and adaptive doses to the target volume and the OARs were recorded to evaluate the value of adaptation. We used a paired t-test to compare PTV100 between the adaptive and non-adaptive techniques and Chi2 tests to compare the probability of dose constraint failures for OARs. Results: Adaptive MR-IGRT improved target coverage. Mean PTV100 for adaptive and non-adaptive techniques was 89.9% [88.4-90.4] and 78.4% [27.3-96.6] respectively, p = 0.0017. There were no statistically significant differences for violations of dose constraints of OARs using adaptive vs. non-adaptive techniques. Point maxima violations above 35 Gy to duodenum occurred in 6 adaptive fractions (renormalized to 90%) vs. 12 non-adaptive fractions (p = 0.118); to stomach in 8 adaptive fractions vs. 9 non-adaptive fractions (p = 0.790), and to bowel in 9 adaptive fractions vs. 6 non-adaptive fractions (p = 0.401). When adapting, attention must be paid to other OARs in the area: Spinal cord point maxima were violated in 4 adaptive fractions. Conclusions: This study demonstrates that adaptive techniques significantly increase SBRT dose delivered to LAPC without significantly increasing dose constraint violations to OARs. Adaptive MR-IGRT may allow for further SBRT dose escalations
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Is checkpoint inhibitor pneumonitis underreported in patients with advanced non-small cell lung cancer (NSCLC) on PD-1 inhibitor monotherapy?
9579 Background: For patients with advanced non-small cell lung cancer (NSCLC), immunotherapy (ImT) has led to improvements in survival and quality of life. Checkpoint inhibitor pneumonitis (CIP) is an uncommon but sometimes life-threatening adverse event. While CIP is a diagnosis of exclusion, many oncologists believe the incidence of CIP is underreported. Radiomics, an image analysis technique that can extract imperceptible information from radiographic images, has been incorporated into predictive models for many cancers. Recent studies suggest that radiomic analysis of pre-ImT imaging can predict CIP. We hypothesized that for patients with advanced NSCLC treated with Nivolumab monotherapy, the rate of CIP is underreported and radiomics features can identify CIP that was clinically misclassified. Methods: From an IRB-approved database (DB) of 159 patients with advanced NSCLC treated with Nivolumab, chart review identified 8 patients diagnosed with CIP of any grade (5%). 42 additional patients from the same DB without diagnosis of CIP were randomly selected for analysis. For all 50 patients, uninvolved lung in the last pre-ImT CT imaging study was segmented, delineated, and analyzed for radiomics features associated with CIP. A logistic regression model incorporating radiomics assigned a CIP probability score to every patient. Results: Six radiomics features correlated with CIP ( p-values range from 0.02 to 0.03). Each feature had an AUC of ~0.79 (range 0.789 to 0.794) showing large effect size, with odds ratios greater than 3.50 (4 features) or less than 0.3 (2 features). The radiomics-based probability model assigned 7/42 patients (17.5%) without clinical diagnosis of CIP a greater than 50% probability of CIP. Chart review revealed that 6/7 “misclassified” patients exhibited symptoms or radiographic features highly suggestive of CIP within 5 months of initial immunotherapy treatment. These indications originally had been attributed to disease progression, overshadowed by more severe symptoms or simply mislabeled (e.g. a case of recall pneumonitis was described as "radiation pneumonitis"). Conclusions: For patients with advanced NSCLC treated with nivolumab, the incidence of checkpoint-inhibitor pneumonitis (CIP) is underreported and radiomics features can help identify CIP that has been clinically misclassified. Future directions include expansion of this study across the full database, correlation of radiomics features with blood biomarkers, and the inclusion of tumor burden as an additional covariate in the analysis
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HIDRATE-PRO: A prospective pilot study evaluating a digital behavioral health intervention to improve bladder-filling compliance in patients with prostate cancer receiving radiation
70 Background: Prostate cancer (PCa) patients undergoing radiation therapy (RT) need comfortably full bladders during RT to reduce toxicities. Awareness of this state is lacking, and poor compliance is common with standard of care written/verbal instructions, leading to wasted patient value (PV) and inefficient throughput (TE). Herein, we assessed the feasibility and acceptability of a digital behavioral intervention (DBI) to improve bladder filling compliance, methods for quantifying PV, IT, and behavioral biomarkers. Methods: We enrolled 18 non-metastatic PCa patients in a prospective, single-arm pilot study using a DBI. The DBI consists of a smart water bottle and companion app that tracks water consumption. Additionally, visual alerts (water bottle glow and phone notifications) remind the patient to empty his bladder and drink a personalized volume goal (VG) at a set time. The VG is based on simulation bladder volume and reminders are initially set 1.25 hours prior to scheduled RT. Patients were trained to adjust their VG and notification times to achieve comfortably full bladders. Primary endpoint was met if qualitative (QLC) and quantitative compliance (QNC) were both >80%. Other endpoints include acceptability assessed via Service User Technology Acceptability Questionnaire (SUTAQ), engagement (>80% of patients used the device > 50% of the time) and impact of DBI on PV and TE. For QLC, patients were asked if they prepared their bladders before daily RT. QNC was met if bladder volumes on daily CBCT were > 75% of the simulation’s volume. The SUTAQ was given pre- and post-DBI. PV and TE were measured by time spent in clinic and on the linear accelerator (linac), respectively. Biometric data was probed for insights on optimal drinking behaviors. Results: All endpoints were met. QLC was 100% on 375/398 (94.2%) of total treatments, while QNC was 88.9% on 341/398 (85.7%) total treatments. Patients were accepting of DBI with few privacy concerns (4.33/5.00), believe in benefits (4.00/5.00), high satisfaction (4.56/5.00) and high usability (4.24/5.00). Most patients, 15/18 (83.3%), used the DBI on >50% of treatments and met the engagement requirements. Patients with empty bladders (n=43) spent significantly more time (75.14 vs 50.59 minutes, p=0.007) in clinic than patients who came with full bladders (n=355). Similarly, these patients spent nearly twice as long on the linac (21.63 v 12.50 minutes, p<0.001). Shorter time spent drinking correlated with empty bladders (17.07 vs 27.85 min, p=0.027). Conclusions: This digital intervention trial showed high rates of bladder filling compliance and engagement. High patient-value and throughput efficiency was feasibly quantified by shortened clinic times and linac usage, respectively. Future studies are needed to evaluate clinical outcomes, patient experience and cost benefit. Clinical trial information: NCT04946214
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Can texture analysis of pre-immunotherapy CT imaging predict clinical outcomes for patients with advanced NSCLC treated with Nivolumab?
e20720 Background: Targeted therapies are ineffective in most NSCLC patients and response rates remain 1.5). Fifteen additional texture features trended toward statistical significance with p-values from .05 to .10. In all, 26 out of the 92 texture features showed significant association or trended toward significance with duration of OS. Conclusions: This preliminary study suggests that texture features on pre-immunotherapy CT imaging may help in predicting OS duration for patients with advanced NSCLC treated with Nivolumab monotherapy. We are in the process of validating a multivariate predictive model. Future directions include expansion of this study across the full database, survival analyses and correlation of texture features with tissue biology
ATLAS
% ATLAS \\ \\ ATLAS is a general-purpose experiment for recording proton-proton collisions at LHC. The ATLAS collaboration consists of 144 participating institutions (June 1998) with more than 1750~physicists and engineers (700 from non-Member States). The detector design has been optimized to cover the largest possible range of LHC physics: searches for Higgs bosons and alternative schemes for the spontaneous symmetry-breaking mechanism; searches for supersymmetric particles, new gauge bosons, leptoquarks, and quark and lepton compositeness indicating extensions to the Standard Model and new physics beyond it; studies of the origin of CP violation via high-precision measurements of CP-violating B-decays; high-precision measurements of the third quark family such as the top-quark mass and decay properties, rare decays of B-hadrons, spectroscopy of rare B-hadrons, and -mixing. \\ \\The ATLAS dectector, shown in the Figure includes an inner tracking detector inside a 2~T~solenoid providing an axial field, electromagnetic and hadronic calorimeters outside the solenoid and in the forward regions, and barrel and end-cap air-core-toroid muon spectrometers. The precision measurements for photons, electrons, muons and hadrons, and identification of photons, electrons, muons, -leptons and b-quark jets are performed over < 2.5. The complete hadronic energy measurement extends over < 4.7. \\ \\The inner tracking detector consists of straw drift tubes interleaved with transition radiators for robust pattern recognition and electron identification, and several layers of semiconductor strip and pixel detectors providing high-precision space points. \\ \\The e.m. calorimeter is a lead-Liquid Argon sampling calorimeter with an integrated preshower detector and a presampler layer immediately behind the cryostat wall for energy recovery. The end-cap hadronic calorimeters also use Liquid Argon technology, with copper absorber plates. The end-cap cryostats house the e.m., hadronic and forward calorimeters (tungsten-Liquid Argon sampling). The barrel hadronic calorimeter is an iron-scintillating tile sampling calorimeter with longitudinal tile geometry. \\ \\Air-core toroids are used for the muon spectrometer. Eight superconducting coils with warm voussoirs are used in the barrel region complemented with superconducting end-cap toroids in the forward regions. The toroids will be instrumented with Monitored Drift Tubes (Cathode Strip Chambers at large rapidity where there are high radiation levels). The muon trigger and second coordinate measurement for muon tracks are provide