Introduction: Heterogeneity correction is an important parameter in dose calculation for cancer patients where it may be cause inaccuracy in dose calculation as a result of different densities of patients. This study studied the impact of dose calculation of breast cancer patients with and without heterogeneity correction. Material and Methods: Twenty breast cancer patients were treated with Th...

background: most of the current brachytherapy treatment planning systems (tps) use the tg-43u1 recommendations for dosimetry in water phantom, not considering the heterogeneity effects. objective: the purpose of this study is developing a method for obtaining correction factors for heterogeneity for cs-137 brachytherapy sources based on pre-calculated mc simulations and interpolation. method: t...

Background: Most of the current brachytherapy treatment planning systems (TPS) use the TG-43U1 recommendations for dosimetry in water phantom, not considering the heterogeneity effects.Objective: The purpose of this study is developing a method for obtaining correction factors for heterogeneity for Cs-137 brachytherapy sources based on pre-calculated MC simulations and interpolation.Method: To ...

Heterogeneity correction algorithms can have a large impact on the dose distributions of stereotactic body radiation therapy (SBRT) for lung tumors. Treatment plans of 20 patients who underwent SBRT for lung tumors with the prescribed dose of 48 Gy in four fractions at the isocenter were reviewed retrospectively and recalculated with different heterogeneity correction algorithms: the pencil bea...

Recently, stereotactic body radiotherapy (SBRT) for lung cancer is conducted with heterogeneity-corrected treatment plans, as the correction greatly affects the dose delivery to the lung tumor. In this study, the correlation between the planning target volume (PTV) and the dose delivery is investigated by separation of the heterogeneity correction effects into photon attenuation and electron tr...

Background: The prevention and correction of vitamin D deficiency requires a precise depiction of the current situation and identification of risk factors in each region. The present study attempted to determine these entities using a systematic review and meta-analysis in Iran.Methods: Articles published online in Persian and English between 2000 and November 1, 2016, were reviewed. This was c...

BACKGROUND Physiological measures per lung parenchyma, rather than per lung volume, sometimes reflect the disease status. PET images of the lung, which are usually expressed per lung volume, could confound the interpretation of the disease status, especially in cases with a prominent heterogeneity in aeration. The aim of the present study was to develop a method for measuring pulmonary blood fl...