Citations

AbstractBackgroundMotion of lung tumors during radiotherapy leads to decreased accuracy of the delivered dose distribution. This is especially true for proton radiotherapy due to the finite range of the proton beam. Methods for mitigating motion rely on knowing the position of the tumor during treatment.PurposeProton radiography uses the treatment beam, at an energy high enough to traverse the patient, to produce a radiograph. This work shows the first results of using an integrated‐mode proton radiography system to track the position of moving objects in an experimental phantom study; demonstrating the potential of using this method for measuring tumor motion.MethodsProton radiographs of an anthropomorphic lung phantom, with a motor‐driven tumor insert, were acquired approximately every 1 s, using tumor inserts of 10, 20, and 30 mm undergoing a known periodic motion. The proton radiography system used a monolithic scintillator block and digital cameras to capture the residual range of each pencil beam passing through the phantom. These ranges were then used to produce a water equivalent thickness map of the phantom. The centroid of the tumor insert in the radiographs was used to determine its position. This measured position was then compared to the known motion of the phantom to determine the accuracy.ResultsSubmillimeter accuracy on the measurement of the tumor insert was achieved when using a 30 mm tumor insert with a period of 24 s and was found to be improved for decreasing motion amplitudes with a mean absolute error (MAE) of 1.0, 0.9, and 0.7 mm for 20, 15, and 10 mm respectively. Using smaller tumor inserts reduced the accuracy with a MAE of 1.8 and 1.9 mm for a 20 and 10 mm insert respectively undergoing a periodic motion with an amplitude of 20 mm and a period of 24 s. Using a shorter period resulted in significant motion artifacts reducing the accuracy to a MAE of 2.2 mm for a 12 s period and 3.1 mm for a 6 s period for the 30 mm insert with an amplitude of 20 mm.ConclusionsThis work demonstrates that the position of a lung tumor insert in a realistic anthropomorphic phantom can be measured with high accuracy using proton radiographs. Results show that the accuracy of the position measurement is the highest for slower tumor motions due to a reduction in motion artifacts. This indicates that the primary obstacle to accurate measurement is the speed of the radiograph acquisition. Although the slower tumor motions used in this study are not clinically realistic, this work demonstrates the potential for using proton radiography for measuring tumor motion with an increased scanning speed that results in a decreased acquisition time.

ABSTRACTApheresis is performed worldwide for an increasing number of indications. The development of common data elements (CDE) for apheresis related areas may facilitate conduct of new research, enhance quality initiatives including benchmarking, and improve patient care. This report describes the systematic development of the Uniform Apheresis Case Report Form (UACRF) as part of the Apheresis in the United States (ApheresUS) program. A consensus panel of 17 diverse experts in apheresis, related specialties, and electronic case report form (eCRF), and database development was assembled. The panel met via online conferencing from November 17, 2020 to December 1, 2021. A draft document was posted online for public comment from October 11, 2021 to November 10, 2021. Feedback was collected using an online survey tool. The consensus panel revised the UACRF. This version was converted to an eCRF with additional changes made to improve usability in this format. The final version of the UACRF was created on August 24, 2023. The UACRF contains 16 modules: procedure and subject eligibility, patient demographics, general procedure information, laboratory parameters, vascular access, common procedure elements, eight procedure specific modules (mononuclear cell collection and seven therapeutic modalities), outcomes, and site information. A total of 137 data elements were created, including 57 with one or more subelements. The UACRF is the first systematic attempt to develop CDE for therapeutic apheresis and white blood cell collections. Further validation of the UACRF is necessary to confirm the tool's ability to collect the relevant data elements and determine the usability of the form.

Abstract Background: Genome-wide association studies (GWAS) have linked single nucleotide polymorphisms (SNPs) to pancreatic ductal adenocarcinoma (PDAC) risk at over 20 genomic loci. The Pancreatic Cancer Cohort Consortium and Pancreatic Cancer Case-Control Consortium are currently expanding on previous GWAS studies for PDAC from ∼9,000 cases and ∼12,000 controls to ∼36,000 cases and ∼800,000 controls in individuals of European and Asian ancestry. This ongoing GWAS phase is estimated to detect up to 50 new risk signals. Post-GWAS studies aim to fine-map and functionally assess risk variants in disease-relevant cell types and contexts to identify target genes and underlying mechanisms of risk. Massively parallel reporter assays (MPRAs) are a powerful method of assessing allele-specific gene regulatory effects. Integrating sequences into the genome using lentiviruses (Lenti-MPRA) enables the capture of variant function in the context of the native cellular chromatin. An added benefit is that Lenti-MPRAs can be used for difficult to transfect cells such as primary cells, that often reflect the disease relevant cell types. Methods: We have used a lentiviral MPRA to test 228 fine-mapped SNPs at the chr5p15.33 multi-cancer risk locus in PDAC cell lines (MIA PaCa-2, PANC-1) and the normal-derived ductal pancreas (HPDE) cell line. Additionally, we have optimized the transduction of large MPRA libraries into primary pancreas cells. Tunicamycin was used to induce ER stress in cell lines and primary cells, assessing downstream gene expression using RT-qPCR. Results: Our pilot MPRA demonstrated high reproducibility in PDAC cell lines (r2=0.93-0.97, MIA PaCa-2, PANC-1 cells) and normal-derived pancreatic ductal cells (r2=0.68-0.86, HPDE cells). We identified 33 SNPs out of 228 with significant allele-specific transcriptional activity in PDAC cell lines and 5 in HPDE cells (FDR ≤0.05). An additional 6-15% of variants exhibited significant allele-specific transcriptional activity when in the frames of the SNP-centered tested oligos were shifted left or right. We demonstrate the inducibility of ER-stress with tunicamycin treatment over 24 hours in cells lines and primary pancreatic cells. Additionally, we observed increased expression of CLPTM1IL at the chr5p15.33 locus after tunicamycin treatment over 24 hours in cell lines and primary pancreatic cells, suggesting ER-stress and inflammation may influence gene expression at this locus. Conclusions: Lentiviral MPRA assays in commonly used PDAC cell lines have demonstrated good reproducibility. The optimization studies and preliminary work in primary pancreatic cells provide a solid foundation for the next steps of assessing all GWAS loci in ER stress, an important disease relevant condition. Citation Format: Minal B Patel, Aidan O'Brien, Jun Zhong, Irene Collins, Jason W Hoskins, Stephen J Chanock, Samuel O Antwi, Rachel Z Stolzenberg-Solomon, Alison P Klein, Brian M Wolpin, Sara Lindström, H. Efsun Arda, Kevin M Brown, Katelyn E Connelly, Laufey T Amundadottir, Meagan Jezek. The functional characterization of pancreatic ductal adenocarcinoma GWAS risk variants in primary pancreatic cells – A pilot study [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A018.

Context.— Gastrointestinal manifestations of Kaposi sarcoma are rare but may cause morbidity. Lower gastrointestinal involvement is particularly rare, and lesions may resemble conventional bowel polyps. Objective.— To study 15 patients who presented with lower gastrointestinal tract Kaposi sarcoma with polypoid architecture. Design.— The surgical pathology files of the departments of pathology at multiple institutions were searched for cases of Kaposi sarcoma forming polyps in the lower gastrointestinal tract (jejunum, colon, rectum); 15 cases with such features were identified. Clinicopathologic information was extracted from the medical record and documented by reviewing individual hematoxylin-eosin–stained slides. Results.— The patients were 13 men and 2 women aged 26–80 years (median = 44 years). Gastrointestinal tract involvement was multifocal in 11 cases and unifocal in 4. The tumors involved the rectum, rectosigmoid junction, cecum, ascending colon, transverse colon, and descending colon and presented as polypoid lesions measuring 0.2–2.1 cm. Six patients had upper gastrointestinal tract involvement in addition to lower gastrointestinal lesions. Histologically, the tumors were characterized in 6 cases by a dense spindle cell proliferation in the lamina propria; however, the remaining cases showed only a subtle fascicular spindle cell proliferation in the lamina propria that did not form an expansile mass. Conclusions.— Biopsies of gastrointestinal polyps showing absence of the common features of hyperplastic or adenomatous polyps, particularly in immunocompromised patients, should be carefully examined for the presence of a stromal spindle cell proliferation. Use of immunohistochemical stains, particularly human herpesvirus-8, can help in establishing the correct diagnosis.

Abstract Aims To assess the reproducibility of interpreting hypoattenuated thickening (HAT) and peridevice leak (PDL) using cardiac computed tomography (CT) imaging following Watchman FLX left atrial appendage closure (LAAC). Methods and results In this multicentre retrospective reproducibility study, 100 anonymized post-LAAC cardiac CT scans were evaluated within the same cardiac phase by an experienced and a novice rater blinded to prior evaluations. All scans were evaluated twice by each rater, assessing overall HAT and PDL categories as well as specific associated findings based on suggested algorithms for post-LAAC interpretation. Inter- and intra-rater agreement and reliability were evaluated using absolute agreement, Cohen’s kappa, and Kendall’s tau for categorical variables, and mean difference, Bland–Altman plots, limits of agreement (lower and upper), and intra-class correlation coefficients (ICCs) for continuous variables. Within overall categories of both HAT and PDL, substantial agreement (kappa ≥0.61) and reliability (Kendall’s tau-b ≥ 0.75) were observed. Specifically, identifying high-grade HAT (kappa ≥0.78) and distal patency (kappa ≥0.85) displayed the highest agreement within HAT and PDL interpretation. Meanwhile, measuring the height of the proximal screw hub cove represented the least reliable HAT assessment among both inter- and intra-rater comparisons (ICC < 0.75), while suspected leak mechanism represented the least reproducible PDL measure. Conclusion Despite only minimal training of one rater, overall high levels of inter- and intra-rater agreement and reliability were observed across the chosen algorithms for interpretation of HAT and PDL following Watchman FLX LAAC. The prognostic implications of the included variables are to be explored in future trials and registries.

INTRODUCTION: Prophylactic pancreatic stent placement (PSP) is effective for preventing pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP) in high-risk cases, but the optimal technical approach to this intervention remains uncertain. METHODS: In this secondary analysis of 787 clinical trial patients who underwent successful stent placement, we studied the impact of (i) whether pancreatic wire access was achieved for the sole purpose of PSP or naturally during the conduct of the case, (ii) the amount of effort expended on PSP, (iii) stent length, (iv) stent diameter, and (v) guidewire caliber. We used logistic regression models to examine the adjusted association between each technical factor and post-ERCP pancreatitis (PEP). RESULTS: Ninety-one of the 787 patients experienced PEP. There was no clear association between PEP and whether pancreatic wire access was achieved for the sole purpose of PSP (vs occurring naturally; odds ratio [OR] 0.82, 95% confidence interval [CI] 0.37–1.84), whether substantial effort expended on stent placement (vs nonsubstantial effort; OR 1.58, 95% CI 0.73–3.45), stent length (>5 vs ≤5 cm; OR 1.01, 95% CI 0.63–1.61), stent diameter (≥5 vs <5 Fr; OR 1.13, 95% CI 0.65–1.96), or guidewire caliber (0.035 vs 0.025 in; 0.83, 95% CI 0.49–1.41). DISCUSSION: The 5 modifiable technical factors studied in this secondary analysis of large-scale randomized trial data did not appear to have a strong impact on the benefit of prophylactic PSP in preventing PEP after high-risk ERCP. Within the limitations of post hoc subgroup analysis, these findings may have important implications in procedural decision making and suggest that the benefit of PSP is robust to variations in technical approach.

Abstract Although the 2022 European LeukemiaNet (ELN) acute myeloid leukemia (AML) risk classification reliably predicts outcomes in younger patients treated with intensive chemotherapy, it is unclear whether it applies to adults ≥60 years treated with lower-intensity treatment (LIT). We aimed to test the prognostic impact of ELN risk in patients with newly diagnosed (ND) AML aged ≥60 years given LIT and to further refine risk stratification for these patients. A total of 595 patients were included: 11% had favorable-, 11% intermediate-, and 78% had adverse-risk AML. ELN risk was prognostic for overall survival (OS) (P &lt; .001) but did not stratify favorable- from intermediate-risk (P = .71). Within adverse-risk AML, the impact of additional molecular abnormalities was further evaluated. Multivariable analysis was performed on a training set (n = 316) and identified IDH2 mutation as an independent favorable prognostic factor, and KRAS, MLL2, and TP53 mutations as unfavorable (P &lt; .05). A “mutation score” was calculated for each combination of these mutations, assigning adverse-risk patients to 2 risk groups: −1 to 0 points (“Beat-AML intermediate”) vs 1+ points (“Beat-AML adverse”). In the final refined risk classification, ELN favorable- and intermediate-risk were combined into a newly defined “Beat-AML favorable-risk” group, in addition to mutation scoring within the ELN adverse-risk group. This approach redefines risk for older patients with ND AML and proposes refined Beat-AML risk groups with improved discrimination for OS (2-year OS, 48% vs 33% vs 11%, respectively; P &lt; .001), providing patients and providers additional information for treatment decision-making.

Abstract Purpose: Early detection of neurofibromatosis type 1 (NF1)–associated peripheral nerve sheath tumors (PNST) informs clinical decision-making, enabling early definitive treatment and potentially averting deadly outcomes. In this study, we describe a cell-free DNA (cfDNA) fragmentomic approach that distinguishes nonmalignant, premalignant, and malignant forms of PNST in the cancer predisposition syndrome, NF1. Experimental Design: cfDNA was isolated from plasma samples of a novel cohort of 101 patients with NF1 and 21 healthy controls and underwent whole-genome sequencing. We investigated diagnosis-specific signatures of copy-number alterations with in silico size selection as well as fragment profiles. Fragmentomics were analyzed using complementary feature types: bin-wise fragment size ratios, end motifs, and fragment non-negative matrix factorization signatures. Results: The novel cohort of patients with NF1 validated that our previous cfDNA copy-number alteration–based approach identifies malignant PNST (MPNST) but cannot distinguish between benign and premalignant states. Fragmentomic methods were able to differentiate premalignant states including atypical neurofibromas (AN). Fragmentomics also adjudicated AN cases suspicious for MPNST, correctly diagnosing samples noninvasively, which could have informed clinical management. Conclusions: Novel cfDNA fragmentomic signatures distinguish AN from benign plexiform neurofibromas and MPNST, enabling more precise clinical diagnosis and management. This study pioneers the early detection of malignant and premalignant PNST in NF1 and provides a blueprint for decentralizing noninvasive cancer surveillance in hereditary cancer predisposition syndromes.