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All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Improved accuracy of S-value-based dosimetry: a guide to transition from Cristy–Eckerman to ICRP adult phantoms

Background: In 2016, the International Commission on Radiological Protection (ICRP) published the results of Monte Carlo simulations performed using updated and anatomically realistic voxelized phantoms. The resulting specific absorbed fractions are based on more realistic human anatomy than those computed in the stylized, geometrical Cristy–Eckerman (CE) phantom. Despite this development, the ICRP-absorbed fractions have not been widely adopted for radiopharmaceutical dosimetry. To help make the transition, we have established a correspondence between source and target tissues defined in the CE phantom and those defined in the ICRP phantoms. Results: The ICRP phantom has 79 source regions and 43 target regions in comparison with the 23 source and 18 target tissue regions defined in the CE phantom. The ICRP phantom provides tissue regions with greater anatomical detail. Some of this additional detail is focused on radiation protection and dosimetry of inhaled/ingested radioactivity. Some, but not all, of this detail is useful and appropriate for radiopharmaceutical therapy. We have established the correspondence between CE and ICRP phantom source and target regions and attempted to highlight the ICRP source tissues relevant to radiopharmaceutical therapy (RPT). This paper provides tables and figures highlighting the correspondences established. Conclusion: The results provide assistance in transitioning from CE-stylized phantoms to the anatomically accurate voxelized ICRP phantoms. It provides specific guidance for porting the total absorbed activity for regions as defined in the CE phantom to regions within the ICRP phantoms.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2019

The Value of {sup 99m}Tc-PSMA SPECT/CT-Guided Surgery for Identifying and Locating Lymph Node Metastasis in Prostate Cancer Patients

Background: This study evaluated the effect of technetium-99m ({sup 99m}Tc)-labeled prostate-specific membrane antigen (PSMA)-based image-guided surgery on the oncologic outcomes for patients with primary or recurrent prostate cancer (PCa). Methods: This study retrospectively analyzed 54 consecutive patients with PCa who underwent {sup 99m}Tc-labeled PSMA-based image-guided surgery between January 2016 and September 2017. These patients received a radical prostatectomy (RP) with pelvic lymph node dissection (PLND) or salvage lymph node dissection (sLND). The resected specimens were compared with findings of postoperative histologic analysis. The responses to the treatment were recorded during the follow-up period. Results: In 31 patients, PSMA single-photon emission computerized tomography (SPECT) and computed tomography (CT) could find 52 suspicious lymph node metastases (LNMs). With the help of PSMA SPECT/CT, 12 patients with recurrence received sLND, 19 primary PCa patients received RP with extended PLND, and 23 primary PCa patients received RP with standard PLND. The findings showed that PSMA SPECT/CT could detect LNMs with high sensitivity and specificity. In six patients, PSMA SPECT/CT could find more LNMs that were not found by MRI and help to modify the extent of lymphadenectomy. At the latest follow-up evaluation, 39 patients showed a biochemical response (BR), 9 patients showed a biochemical recurrence (BCR) after BR, and 6 patients never exhibited BR. The patients who received RP with standard PLND or extended PLND had a better prostate-specific antigen (PSA) response than the patients who received sLND. The patients with pelvic LNMs also had a better PSA response than the patients with retroperitoneal LNMs. Conclusions: This study showed that {sup 99m}Tc-PSMA SPECT/CT-guided surgery can remove more LNMs than conventional imaging with high sensitivity and specificity and delay disease progression in PCa patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Data for Complete and Efficient Conversion of Plant Cell Wall Hemicellulose into High-Value Bioproducts by Engineered Yeast

Plant cell wall hydrolysates contain not only sugars but also substantial amounts of acetate, a fermentation inhibitor that hinders bioconversion of lignocellulose. Despite the toxic and non-consumable nature of acetate during glucose metabolism, we demonstrate that acetate can be rapidly co-consumed with xylose by engineered Saccharomyces cerevisiae . The co-consumption leads to a metabolic re-configuration that boosts the synthesis of acetyl-CoA derived bioproducts, including triacetic acid lactone (TAL) and vitamin A, in engineered strains. Notably, by co-feeding xylose and acetate, an engineered strain produces 23.91 g/L TAL with a productivity of 0.29 g/L/h in bioreactor fermentation. This strain also completely converts a hemicellulose hydrolysate of switchgrass into 3.55 g/L TAL. These findings establish a versatile strategy that not only transforms an inhibitor into a valuable substrate but also expands the capacity of acetyl-CoA supply in S. cerevisiae for efficient bioconversion of cellulosic biomass.

Conversion↗
DOE OSTI2018

Western USA Assessment of High Value Materials in Geothermal Fluids and Produced Fluids

This submission includes the following: - Field Characteristics: Describes the geological and production field characteristics of sampling sites - Geochemistry of Produced Fluids Idaho-Nevada-New Mexico-Oregon-Utah: Summarizes the all the analytical results for aqueous samples collected from geothermal production wells, hydrocarbon production wells, and hot springs. - Geochemistry of Reservoir Rocks & Calcite Scales Nevada-Utah: Analytical results of trace element analyses of reservoir drill cuttings from Beowawe, Dixie Valley, Roosevelt Hot Springs, Uinta Basin, and Paradox Basin (Aneth field); also includes analyses of Dixie Valley calcite scales and rocks in the Sevier Thermal Belt, Utah. - Lithology and mineralogy of drill cuttings from Beowawe, Dixie Valley and Roosevelt Hot Springs: Lithological and mineralogical characterization of drill cuttings from Beowawe, Dixie Valley and Roosevelt Hot Springs - Geological Settings of Critical Element Mineral Deposits: Brief summary and references regarding the geological settings of critical element mineral deposits

15 GEOTHERMAL ENERGY↗