This is expected to be a feasible method for measuring the change of Na in bone. The low detection limit indicates this will be a useful system to study the association between Na retention and related diseases.

Objective: The locations of sodium (Na) storage and its exchange mechanisms in the body are not well known. Understanding tissue Na storage and exchange is important for understanding the impact of Na intake, absorption, and retention on human health, especially on the risk of developing chronic diseases. The purpose of this study was to investigate the application of a deuterium-deuterium (DD) neutron generator-based IVNAA system in Na nutrition studies. Approach: The right legs of two live pigs, one on a low Na diet and one on a high Na diet, both for 14 d, were irradiated inside a customized irradiation cave for 10 min (45 mSv dose to the leg) and then measured with a 100% efficient high purity germanium detector (HPGe). The spectra were analyzed to obtain the net Na counts at different time points. Bone Na concentrations were calculated using the calibration created with Na bone phantoms. Main results: The results show that the difference in bone Na to calcium between the pigs on high versus low Na diets was 466 ± 137 ppm. The estimated bone Na to calcium concentrations were 1166 ± 80 and 1631 ± 111 ppm for low and high Na diet pigs, respectively. Analysis also shows rapid exchange of Na in the leg during the first 2 h measurements, while the exchange was minimal at the second and third 2 h measurements, taken 7 and 21 h post irradiation. The exchange decay time of Na in the leg was 51 min for the first measurement, and there was no significant change of Na activities between 2-21 h. Significance: With these results, we conclude there is a non or low exchangeable compartment (likely to be bone) for Na storage and that DD neutron generator-based IVNAA is a useful method for determining tissue Na distribution in nutrition studies.

The purpose of this report is to present the implementation of a process for after-hours radiation treatment (RT) utilizing remote treatment planning based on optimized diagnostic computed tomography (CT) scans for the urgent palliative treatment of inpatients. A standardized operating procedure was developed by an interprofessional panel to improve the quality of after-hours RT and minimize the risk of treatment errors. A new diagnostic CT protocol was created that could be performed after-hours on hospital scanners and would ensure a reproducible patient position and adequate field of view. An on-call structure for dosimetry staff was created utilizing remote treatment planning. The optimized CT protocol was developed in collaboration with the radiology department, and a novel order set was created in the electronic health system. The clinical workflow begins with the radiation oncologist notifying the on-call team (therapist, dosimetrist, and physicist) and obtaining an optimized diagnostic CT scan on a hospital-based scanner. The dosimetrist remotely creates a plan; the physicist checks the plan; and the patient is treated. Plans are intentionally simple (parallel opposed fields, symmetric jaws) to expedite care and reduce the risk of error. Education on the new process was provided for all relevant staff. Our process was successfully implemented with the use of an optimized CT protocol and remote treatment planning. This approach has the potential to improve the quality and safety of emergent after-hours RT by better approximating the normal process of care.

Sodium is an essential mineral in the human body that is vital for many body functions. The role of dietary sodium in hypertension and associated diseases has been widely accepted; however, few studies have been conducted on how sodium is stored and metabolized in the human body. This study aimed to evaluate the feasibility of a compact neutron generator-based neutron activation analysis system for the in vivo quantification of sodium in pig models. Two six-week-old male pigs were fed a high and low-concentration sodium diet for 14 days. The in vivo bone sodium was measured with a DD110 neutron generator-based irradiation system. The hind leg of pigs was irradiated for 10 minutes, and the gamma spectrum with 23Na was collected using high efficiency, high purity germanium (HPGe) detector. The in vivo sodium concentration in two male pigs was found to be (788 ±11 ppm) and (785±10 ppm) at the end of the dietary sodium period. There was no significant difference for in vivo bone sodium of low-sodium (pig L) and high-sodium diet pig (pig H) after 14 days of dietary sodium intervention. In contrast, the ex-vivo bone sodium concentrations for pig L (1870±11 ppm) and pig H (2029 ±6 ppm) showed a significant difference in the bone sodium deposition in pig H and pig L as a response to the sodium diet. In conclusion, this experimental study shows that IVNAA technique can be successfully used to quantify bone sodium in response to the dietary interventions.

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