Dose proportionality/linearity is a desirable property in pharmacokinetic studies. Various methods have been proposed for its assessment. When dose proportionality is not established, it is of interest to evaluate the degree of departure from dose linearity. In this paper, we propose a measure of departure from dose linearity and derive an asymptotic test under a repeated measures incomplete bl...

Background: We have validated the monitor unit calculations from a commercially available treatment planning system (TPS) for three intensity modulated radiotherapy (IMRT) planning techniques for tangential breast irradiation by using ionization chamber measurements. Materials and Methods: Treatment plans were generated for forty-two breast patients by a forward planned field in field ...

Purpose: Evaluation of the newly integrated system for its validation and designing a quality assurance frame work to assess its geometrical, radiological and mechanical accuracy. Methods: Isocentric accuracy of two independent imaging modalities, kV based ExacTrac and MV based iViewGT was evaluated using Winston-Lutz test. A pelvic humanoid phantom was used for the radiological end-to-end test...

Introduction: Best radiography practice involves operational optimal machine performance, delivering cost-effective healthcare services under appropriate safety conditions for workers and the public. The present study aimed to investigate the safety status of diagnostic X-ray installations in Mizoram, India. Material and Methods: Lineari...

Nuclear Regulatory Commission (NRC) guidelines state that dose calibrators must be tested for linearity upon installation and quarterly thereafter over a range of activities from 10 ~J,Ci (370 kBq) to the highest dose administered to the patient (300 mCi [11.1 GBq] ofiodine-131 for therapy at our institution). The simplest method of linearity testing utilizes commercial attenuator kits. These k...

OBJECTIVE The present study was aimed at evaluating the viability of replacing (18)F with (99m)Tc in dose calibrator linearity testing. MATERIALS AND METHODS The test was performed with sources of (99m)Tc (62 GBq) and (18)F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical (99m)Tc and (18)F sources activities were...

background: in order to deliver the precise dose to the target in radiotherapy, absorbed dose to water at the reference point should be assessed. when the calibration procedure is performed for a reference dosimeter in the 60co beam of a secondary standard dosimetry laboratory (ssdl), the total uncertainty in absorbed dose to water (dw) is estimated to be approximately 1.5%. this study attempts...

Background: In order to deliver the precise dose to the target in radiotherapy, absorbed dose to water at the reference point should be assessed. When the calibration procedure is performed for a reference dosimeter in the 60Co beam of a Secondary Standard Dosimetry Laboratory (SSDL), the total uncertainty in absorbed dose to water (Dw) is estimated to be approximately 1.5%. This study attempts...

A remarkable non-linearity was found between dose and transfection activities of non-viral gene delivery systems, such as a Lipofectamine/DNA complex and an octaarginine-modified multifunctional envelope-type nano device (R8-MEND). We measured the nuclear delivery of pDNA to distinguish the non-linearity in intracellular pharmacokinetics or pharmacodynamics after transfection with R8-MEND at di...