Beta particles software#

Additionally, they found the absorbed fractions in the source region for various radionuclides as a function of the surface-to-volume ratio.Ī spherical model is employed to model nodules and other small regions in human dosimetry, as well as for whole non-human organisms in an environmental radioactivity pollution assessment. They showed that for volumes with radii greater than the range of the electrons, the use of mean beta energy of the beta spectrum gave a good approximation to the absorbed fraction, when compared to the results acquired by the extended beta spectra of the radionuclides. ( 11) estimated the beta absorbed fractions in small spherical volumes of tissue for a number of radionuclides by using mean energy and the entire beta spectrum. Since the adopted criteria in nuclear medicine planning are based on tolerance doses, it highlights the importance of critical organ doses that must be estimated accurately.Ī number of the pamphlets published by the MIRD committee have made wide use of the Monte Carlo simulation to calculate the absorbed fractions for beta emitting sources uniformly distributed in organs. This causes discrepancies in dose calculation. When the monoenergetic beta spectrum is used, the quantity of the energy absorbed by the target differs from the actual value ( 11).

Beta particles software#

In dosimetric calculations with commercially available software ( 12), only the monoenergetic spectrum may be taken into account. One of the factors that affect the absorbed fraction is the energy emitted by the source.

In nuclear medicine, the absorbed fraction is an important parameter for calculating the absorbed dose. On the other hand, when this condition is not satisfied the absorbed fraction may be lower and its dependence on the target dimensions and beta energy cannot be overlooked ( 11). The absorbed fraction tends to be unity when the target dimensions are greater than the range of the beta emitted by the source. In the approach presented by the Medical Internal Radiation Dose (MIRD) Committee, beta absorbed fraction is considered equivalent to unity in large organs, but in smaller regions, it is less than unity and differs depending on the size and the geometry of the target organ ( 10). the fraction of emitted energy which is absorbed within the target volume, is an essential issue for both radionuclide internal dosimetry and radiological protection ( 9). The knowledge of radiation absorbed fraction, i.e.

Radiopharmaceuticals labeled with 177Lu, 131I, 90Sr, 153Sm, 186Re, 32P, and 90Y are used for the treatment of various types of cancers such as the palliation of bone metastases and ocular surface tumors, liver tumors, breast cancer, and for metastatic prostate cancer ( 2- 8). Beta-emitting radionuclides are extensively used for the treatment of tumors and various diseases in the form of internal radiotherapy as well as for tumor imaging ( 1).