Dose calculations formulas

Finally, the activity values of the tumoral and non-tumoral liver can be obtained from the transaxial fused images. These will be used to calculate microsphere activity to deliver according to the partition model. In our protocol, we draw five circular ROIs in the hottest tumoral nodules and another five in the non-tumoral liver (all of them of the same size). Alternatively, in the case of a big tumoral mass, we position the five ROIs in five non-consecutive areas of the mass. The mean activity value for the tumoral and non-tumoral ROIs is obtained, and it will be used in the dose calculation formula (Fig. 7.5). 

In contrast to resin microspheres, the dose calculation for glass microspheres is defined by a nominal target dose (150 Gy/kg) and related to the liver mass without regard for the tumor burden, assuming a uniform distribution of the microspheres throughout the liver volume. The following formula is used for dose calculation ... 

Whenever the dose to be administered is different from that listed on the label, the volume to be administered must be calculated. To determine the volume to be administered, die formula for liquid preparations is used. The calculations are die same as tiiose given in the preceding section for parenteral dru s in disposable syringes or cartridges. 

The chemical change in the Fricke dosimeter is the oxidation of ferrous ions in acidic aerated solutions. It is prepared from a -1 mM solution of ferrous or fer-roammonium sulfate with 1 mM NaCl in air-saturated 0.4 M H2S04. Addition of the chloride inhibits the oxidation of ferrous ions by organic impurities, so that elaborate reagent purification is not necessary. Nevertheless, the use of redistilled water is recommended for each extensive use. Absorption due to the ferric ion is monitored at its peak -304-305 nm. The dose in the solution is calculated from the formula... 

Dose in milligrams of iron may also be calculated using the following formula ... 

For subcutaneous infusion, treprostinil is delivered without further dilution at a calculated subcutaneous infusion rate (mL/h) based on a patient s dose (ng/kg/min), weight (kg), and the vial strength (mg/mL) of treprostinil being used. The subcutaneous infusion rate is calculated using the following formula (conversion factor of 0.00006 = 60 min/h x 0.000001 mg/ng) ... 

Renal function impairment- Upon treatment initiation, the recommended zoledronic acid doses for patients with reduced renal function (mild to moderate renal impairment) are listed in the following table. These doses are calculated to achieve the same AUC as that achieved in patients with Ccr of 75 mL/min. Ccr is calculated using the Cockcroft-Gault formula. 

The likely range of the intersex indicator (ISI) for L. littorea was also calculated based on the dose-response relationship for L. littorea as published by Oehlmann (2002) and the spatial distribution of water concentrations. The range of possible ISI values from the 5 and 95 percentile of the exposure concentration distributions were calculated applying Formula 1. 

Body size/weight The average adult dose refers to individuals of medium body build. For obese or lean individuals, doses of drug may be calculated by the formula ... 

To compare doses resulting from different types of radiation it is necessary to formulate a measure of radiation effects on the crystal structure doses can be recalculated to the number of displacements per atom (dpa). A dose of 0.1 dpa, for example, means that one of ten atoms was displaced from its initial position. Equivalent values in dpa units may be calculated for different types of radiation from the effects of its interaction with the crystal lattice. To recalculate a-dose to dpa the following formula is used ... 

The uranium accumulation of tooth enamel is negligibly small while it can be appreciable for dentine. Hence, the efforts to determine the y-ray dose from the external dentine to enamel must be made to assess the equivalent dose, ED, considering the linear uranium uptake and early as well as late uranium uptake using polynomial formula for some fossils. Laboratory experiments indicated that fresh enamel did not accumulate uranium rapidly but dentine did.8182 The author argue that fitting to a saturation curve rather than a meaningless poly-nominal should be made in a model calculation of uranium-uptake.1... 

The following formula can be used to calculate maintenance dose... 

In the majority of clinical situations, drugs are administered as a series of repeated doses or as a continuous infusion in order to maintain a steady-state concentration. Therefore, a maintenance dose must be calculated such that the rate of input is equal to the rate of drug loss. This may be determined using the following formula ... 

Remember that Equations 7.25 and 7.26 are valid only for the elimination phase of an oral dose. The y-intercept of the line described in Equation 7.26 (In Cpy int) contains a number of factors. If F has already been determined from AUC data (Equation 7.22), the formula for Cpy int (Equation 7.27) can be rearranged to Equation 7.28 for calculation of kah. 

A concern with AUC-targeting based on renal function surrounds the measurement of creatinine clearance. The formulas of Calvert et al. were developed using EDTA clearance, measurement of which is not widely available. They have shown that neither standard measured creatinine clearance, nor the calculation of this index are as accurate or as reproducible. To circumvent this difficulty an alternative dosing strategy has been developed by Chatelut, Canal and co-workers [226], This dosing approach is being tested in clinical trials. 

Using the Methodic Guides [5] trough an assigned value a, for volumetric activity of / radionuclide in water and a specified human exposure time tj via path j the radiation dose Dij through this path due to water contamination by the indicated nuclide can be calculated via the following formulae ... 

The lowest tested dose (0.075 mg/kg/day) is considered a lowest-observed-adverse-effect level (LOAEL) because of the statistically significant reduction in RBC-AChE seen in male rats dosed with GB Type II. This dose is adjusted to a 7 days/week exposure period by using a factor of 5/7 i.e., 5/7 x 0.075 mg/kg/day = 0.054 mg/kg/day. The RfD can then be calculated according to the following formula ... 

The double-isotope technique is carried out as follows (DeGrazia et al., 1%5). The subject eon.sumes a test food containing caldum-45. About halfway through the absorpbve process, caJcium-47 is injected into a vein, in the form of a solution of CaCb. The absorptive process is about halfway complete at about 2 hours after a meal. The injected Ca is calcium that is 100% absorbed- A urine sample is collected 1 day after the oral aiid intravenous doses of radioactive calcium. The fraction of the oral dose absorbed is calculated by the formula ... 

The user enters the proposed dose of the active ingredient and a target tablet weight is calculated using both a formula determined from an extensive study of previously successful... 

Pharmacokinetic-pharmacodynamic correlations between AUC, response rates, and the extent of myelosuppression have been examined retrospectively in patients with advanced ovarian carcinoma (21,24). AUC values below 4 minutes/mg/ml and exceeding 7 minutes/mg/ml cannot be recommended the former is associated with low response rates and the latter is associated with more pronounced neutropenia and thrombocytopenia without higher response rates. Doses of carboplatin are generally calculated by the Calvert formula (26) ... 

The dose administered should be adjusted in proportion to the reduction of creatinine clearance for patients with renal impairment since they require lower doses to achieve AUCs comparable with those seen with patients with normal renal function. Calvert et al. [64] have proposed the following formula for calculation of dose ... 

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