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At least 703 records · Page 39

Common risk segment mapping: Streamlining exploration for carbon storage sites, with application to coastal Texas and Louisiana

Large-scale deployment of Carbon Capture and Storage (CCS) will require a commensurately large number of sites. Efficient screening methods are needed to create investment assurance and focus efforts on the most promising sites. The problem is similar to petroleum exploration, for which there are well-developed (though seldom published) workflows, including Common Risk Segment (CRS) mapping. In brief, the process requires 1) defining the key play elements; 2) identifying candidate geologic intervals for each; 3) creating fact-based maps for those intervals; 4) determining minimum criteria for the success of each element; 5) reinterpreting the fact-based maps in terms of chance of success; and 6) combining the individual maps to form a composite, basin-scale view of prospectivity. We adapt the CRS process to screening for CO 2 storage sites. Critically, we redefine the process in terms of cost of characterization and development, rather than chance of success. For illustration, we apply the process to the example of the Lower Miocene on the Texas and Louisiana Gulf Coast. We show that the predictions are consistent with historic hydrocarbon production volumes and rates. The power of the CRS method is that it creates a systematic approach to geologic evaluation and translates complex, multidimensional analysis into clear, graphical and easily comprehended business inputs. The results highlight sweet spots and identifies critical risks, suggesting a focus for further data collection and analysis. Furthermore, the method developed here can be applied to both surface and subsurface factors anywhere that there is interest in geologic storage of CO 2 .

54 ENVIRONMENTAL SCIENCES↗

Evaluating offshore legacy wells for geologic carbon storage: A case study from the Galveston and Brazos areas in the Gulf of Mexico

In this article, federal offshore waters in the Gulf of Mexico are of interest for large-scale geologic carbon storage (GCS). However, more than 80,000 offshore oil and gas wells exist in the region, which could impact the integrity of sealing intervals. In this study, we propose a screening methodology for ranking offshore legacy wells based on the challenge they may present to GCS. The methodology relies on the review of well regulatory records to 1) identify leakage pathways and assess the potential hazards that wells pose to planned GCS operations, 2) evaluate well features that impact the accessibility of wells to determine the feasibility of potential corrective actions, and 3) rank wells based on the overall challenge they may pose for GCS. We demonstrate our framework by evaluating the construction and abandonment of 156 wells across eight areas of interest (AOIs) in shallow federal waters along the Texas Gulf Coast. The majority (99.3 %) of wells considered were constructed and plugged in a manner that did not isolate prospective GCS targets in the Upper and Lower Miocene formations and may potentially require a challenging or uncertain corrective action prior to GCS. Dataset trends suggest that the observed well construction and plugging designs may be common in shallow offshore federal waters along the Texas Gulf Coast. Consequently, operators pursuing offshore GCS projects in the region may consider selecting areas that avoid challenging wells or performing robust evaluations of legacy well leakage risks to plan corrective action prior to CO 2 injection.

58 GEOSCIENCES↗

Quantifying CO 2 Plume Stabilization at Carbon Storage Projects, North Dakota, USA

This study presents an approach for quantifying when injected carbon dioxide (CO 2 ) stabilizes pursuant to carbon capture and storage (CCS) project permitting and site closure requirements. The distribution of mobile-phase CO 2 (CO 2 plume) will evolve within the storage reservoir during and after injection through both physical and chemical trapping mechanisms. CCS policies generally agree that the CO 2 plume’s migratory behavior in post-injection should demonstrate nonendangerment to the environment but do not provide specific guidance on how to meet the definition of plume stabilization, generating some uncertainty for operators. Plume stability herein means the CO 2 plume 1) changes size minimally and predictably in the storage reservoir such that it will not cross key boundaries identified in the permit and 2) does not pose a threat to human health, underground sources of drinking water (USDWs), and the environment because of lateral migration to areas where leakage pathways may exist. Published literature on plume metrics was reviewed to determine which metric(s) may be most appropriate for determining CO 2 plume stability. A technical approach that defines plume stabilization by estimating the rate of change in the geographic footprint of the CO 2 plume with respect to time was developed and illustrated using a case study from North Dakota, USA, as a proposed solution for CCS operators to apply at the project permitting stage. Any prospective CCS operator may benefit from using the same approach to inform the selection of pore space lease and monitoring areas and develop post-injection site care plans.

03 NATURAL GAS↗

Predicting nutrition and environmental factors associated with female reproductive disorders using a knowledge graph and random forests

Female reproductive disorders (FRDs) are common health conditions that may present with significant symptoms. Diet and environment are potential areas for FRD interventions. We utilized a knowledge graph (KG) method to predict factors associated with common FRDs (for example, endometriosis, ovarian cyst, and uterine fibroids). We harmonized survey data from the Personalized Environment and Genes Study (PEGS) on internal and external environmental exposures and health conditions with biomedical ontology content. We merged the harmonized data and ontologies with supplemental nutrient and agricultural chemical data to create a KG. We analyzed the KG by embedding edges and applying a random forest for edge prediction to identify variables potentially associated with FRDs. We also conducted logistic regression analysis for comparison. Across 9765 PEGS respondents, the KG analysis resulted in 8535 significant or suggestive predicted links between FRDs and chemicals, phenotypes, and diseases. Amongst these links, 32 were exact matches when compared with the logistic regression results, including comorbidities, medications, foods, and occupational exposures. Mechanistic underpinnings of predicted links documented in the literature may support some of our findings. Our KG methods are useful for predicting possible associations in large, survey-based datasets with added information on directionality and magnitude of effect from logistic regression. These results should not be construed as causal but can support hypothesis generation. This investigation enabled the generation of hypotheses on a variety of potential links between FRDs and exposures. Future investigations should prospectively evaluate the variables hypothesized to impact FRDs.

60 APPLIED LIFE SCIENCES↗

Breast Cancer Molecular Subtype as a Predictor of Radiation Therapy Fractionation Sensitivity

The predictive benefit of breast cancer molecular subtypes for systemic therapy approaches has been well established; yet, there is a paucity of data regarding their use as a predictor of radiation therapy fractionation sensitivity. The purpose of this study was to determine whether rates of local recurrence (LR) for patients treated with hypofractionated (HF) radiation therapy, in comparison to conventional fractionation, differ across breast cancer molecular subtypes in a large, prospectively collected cohort treated with modern systemic therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Radiation Therapy–Induced Changes of the Nasopharyngeal Commensal Microbiome in Nasopharyngeal Carcinoma Patients

The human commensal microbiome has been suggested to be involved in the regulation of response to anticancer therapies. However, little is known regarding changes in commensal microbes in patients with cancer during radiation therapy. We conducted a prospective, longitudinal proof-of-concept cohort study with patients with newly diagnosed nasopharyngeal carcinoma (NPC) who underwent radiation therapy-based treatment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

A Phase 1 Dose Escalation Study of Neoadjuvant SBRT Plus Elective Nodal Radiation with Concurrent Capecitabine for Resectable Pancreatic Cancer

The role of neoadjuvant radiation for resectable pancreatic adenocarcinoma is controversial. We performed a prospective dose-escalation study of neoadjuvant stereotactic body radiation therapy (SBRT) with concurrent capecitabine and elective nodal irradiation (ENI) followed by surgical resection to explore the toxicity and feasibility of this approach.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Hypofractionated Radiation Therapy to the Prostate Bed With Intensity-Modulated Radiation Therapy (IMRT): A Phase 2 Trial

Postoperative radiation therapy (RT) is a common therapy used for patients with prostate cancer. Although clinical trials have established the safety and efficacy of hypofractionation as a primary therapy, there are limited data in a postoperative setting. We conducted a prospective trial to evaluate the safety and feasibility of postoperative hypofractionated RT to the prostate bed.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Phase I Trial of Stereotactic Body Radiation Therapy Dose Escalation in Pancreatic Cancer

Stereotactic body radiation therapy (SBRT) has demonstrated encouraging local tumor control rates in the treatment of pancreatic cancer, yet we lack prospective clinical trials evaluating dose-escalation strategies among patients treated with 5-fraction SBRT. This phase 1 dose-escalation trial was conducted to determine the maximum tolerated dose of SBRT in patients with pancreatic cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Normal Tissue Injury Induced by Photon and Proton Therapies: Gaps and Opportunities

Despite technological advances in radiation therapy (RT) and cancer treatment, patients still experience adverse effects. Proton therapy (PT) has emerged as a valuable RT modality that can improve treatment outcomes. Normal tissue injury is an important determinant of the outcome; therefore, for this review, we analyzed 2 databases: (1) clinical trials registered with ClinicalTrials.gov and (2) the literature on PT in PubMed, which shows a steady increase in the number of publications. Most studies in PT registered with ClinicalTrials.gov with results available are nonrandomized early phase studies with a relatively small number of patients enrolled. From the larger database of nonrandomized trials, we listed adverse events in specific organs/sites among patients with cancer who are treated with photons and protons to identify critical issues. The present data demonstrate dosimetric advantages of PT with favorable toxicity profiles and form the basis for comparative randomized prospective trials. A comparative analysis of 3 recently completed randomized trials for normal tissue toxicities suggests that for early stage non-small cell lung cancer, no meaningful comparison could be made between stereotactic body RT and stereotactic body PT due to low accrual (NCT01511081). In addition, for locally advanced non-small cell lung cancer, a comparison of intensity modulated RT with passive scattering PT (now largely replaced by spot-scanned intensity modulated PT), PT did not provide any benefit in normal tissue toxicity or locoregional failure over photon therapy. Finally, for locally advanced esophageal cancer, proton beam therapy provided a lower total toxicity burden but did not improve progression-free survival and quality of life (NCT01512589). The purpose of this review is to inform the limitations of current trials looking at protons and photons, considering that advances in technology, physics, and biology are a continuum, and to advocate for future trials geared toward accurate precision RT that need to be viewed as an iterative process in a defined path toward delivering optimal radiation treatment. A foundational understanding of the radiobiologic differences between protons and photons in tumor and normal tissue responses is fundamental to, and necessary for, determining the suitability of a given type of biologically optimized RT to a patient or cohort.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

A Phase 1 Dose-Escalation Trial of Radiation Therapy and Concurrent Cisplatin for Stage II and III Triple-Negative Breast Cancer

Patients with triple-negative breast cancer (TNBC) experience higher local-regional recurrence rates than those with luminal or HER2-positive tumors. This prospective, phase 1B trial was designed to assess the safety and to establish the maximum tolerated dose (MTD) of cisplatin with radiation therapy for women with early-stage TNBC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Initial Results of a Phase 2 Trial of 18F-DOPA PET-Guided Dose-Escalated Radiation Therapy for Glioblastoma

Our previous work demonstrated that 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine ({sup 18}F-DOPA) positron emission tomography (PET) is sensitive and specific for identifying regions of high density and biologically aggressive glioblastoma. The purpose of this prospective phase 2 study was to determine the safety and efficacy of biologic-guided, dose-escalated radiation therapy (DERT) using {sup 18}F-DOPA PET in patients with glioblastoma.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Cost-Effectiveness of Prophylactic Cranial Irradiation Versus MRI Surveillance for Extensive-Stage Small Cell Lung Cancer

Owing to conflicting prospective data, controversy exists regarding prophylactic cranial irradiation (PCI) in extensive-stage small cell lung cancer (ES-SCLC). We evaluated the cost-effectiveness of PCI versus magnetic resonance imaging (MRI) surveillance for patients with ES-SCLC based on currently available evidence and in the context of the proposed Centers for Medicare & Medicaid Services alternative payment model.

62 RADIOLOGY AND NUCLEAR MEDICINE↗