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Dose Evaluation of Treatment Plans
Published in W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald, Handbook of Radiotherapy Physics, 2021
Margaret Bidmead, J.-C. Rosenwald
More frequently used, however, are cumulative dose-volume frequency distributions, which are plots of the volume receiving a dose greater than, or equal to, a given dose, against dose. The volume accumulates, starting at the highest dose bin, continuing towards zero dose, and eventually reaching 100% of the total volume (see Figures 43.3 and 43.4). Normally, volumes are expressed as a percentage of the total volume; however, in some situations, the absolute volume may be more appropriate.*
Area and Individual Radiation Monitoring
Published in Arash Darafsheh, Radiation Therapy Dosimetry: A Practical Handbook, 2021
EPDs based on miniature GM counters or silicon detectors are available. EPDs with energy-compensated detectors have an energy dependence within ±20% over the photon energy range of 30 keV to 1.3 MeV. They provide an instantaneous display of the cumulative dose at any time. They also have automatic ranging facilities and provide both visual and audio indications, thus monitoring immediate changes in the radiation field.
Personnel Monitoring
Published in Robert J. Parelli, Principles of Fluoroscopic Image Intensification and Television Systems, 2020
The maximum possible long-term cumulative dose equivalent can be calculated on the basis of 5 Rems/yr. starting at age 18. Therefore, the maximum cumulative whole body dose equivalent is equal to 5 (N - 18), where N is the chronological age in years.
Therapeutic index improvement of antibody-drug conjugates
Published in mAbs, 2023
Hans-Peter Gerber, Sanjeev Gangwar, Alison Betts
We propose that an exposure-based model to calculate TIs is more suitable not only to explain the TI differences between both modalities but also to better understand the improvements in ADC platforms and to inform the selection of clinical ADC candidates. In this model, the pharmacokinetic and pharmacodynamic (PK/PD) parameters are based on drug exposure levels over time, e.g., area under the curve (AUC) and maximum drug concentration (Cmax), as opposed to MTDs or minimal effective doses (MEDs).14,16 In addition, inter-individual variability in drug exposure caused by factors such as genetic polymorphisms of drug metabolizing enzymes, efflux pumps, drug−drug interactions, differences in target antigen expression, body weights, disease, or environmental factors is better accounted for in an exposure-based TI calculation model. Finally, different regimens of a given dose can produce different TIs for the same ADC. For instance, a single dose can be divided into multiple lower doses that yield the same cumulative dose per cycle. An example is the dose fractionation method that was successfully applied for the CD33-ADC Mylotarg in acute myeloid leukemia (AML) patients, where the same total dose administered in three smaller doses improved overall responses and reduced platform toxicities markedly,17 leading to a higher TI value. Such fractionated dose schedules result in a similar AUC and a lower Cmax and therefore improve the TIs of ADCs with Cmax-driven toxicities,18 which cannot be explained by ADC dose levels alone.
Chromosome aberrations, micronucleus frequency, and catalase concentration in a population chronically exposed to high levels of radon
Published in International Journal of Radiation Biology, 2023
Dwi Ramadhani, Sofiati Purnami, Devita Tetriana, Irawan Sugoro, Viria Agesti Suvifan, Nastiti Rahadjeng, Septelia Inawati Wanandi, Heri Wibowo, Ikuo Kashiwakura, Tomisato Miura, Mukh Syaifudin
Details about the measurements of indoor radon concentration can be found in Nugraha et al. (2021). Briefly, four series of radon level measurements were conducted in 2018–2019. The measurements were performed using solid-state nuclear track detectors (SSNTDs), Raduet® (Radosys, Ltd, Hungary). Passive detectors (CR-39) were placed in the house of each participant. After three months of exposure, CR-39 was chemically etched for 24 h in 6 M NaOH at 60 °C. Radon concentrations were then calculated using the alpha track densities identified under an optical microscope. The annual effective dose for each subject was obtained from raw data and calculations available in Nugraha et al. (2021). In brief, the annual effective dose was defined as the total exposure of an individual to both external and internal sources. External exposure originates from environmental gamma radiation, whereas internal exposure comes from ingestion and inhalation. Lastly, the cumulative dose was calculated by multiplying the annual effective dose by the age of each individual.
Low-dose ionizing radiation and cancer mortality among enlisted men stationed on nuclear-powered submarines in the United States Navy
Published in International Journal of Radiation Biology, 2022
George Friedman-Jimenez, Ikuko Kato, Pam Factor-Litvak, Roy Shore
For the main analyses, doses were calculated for each dose period as the previously summed gamma plus neutron equivalent doses in mSv. The computerized dosimetry file contained for each subject the dose for each dose period (of a year or less), and the cumulative dose at the end of each dose period, calculated as the sum of all doses from the beginning of service until the end of that time period. No information was available on IR exposure of cohort members outside of the Navy, such as occupational exposure in the nuclear power industry after discharge or medically-related exposures. All occupational IR doses accumulated while in the Navy were included. Doses received in the Navy before 1969 were included as part of the 1969 cumulative IR dose. Doses received while in the Navy but not stationed on a submarine were included in the years the doses occurred, up through the end of the follow-up period.