introduction the use of cut-outs in electron applicators make changes on output, isodose, and percentage depth dose (pdd) curves. these changes and electron beam dose distribution in the form of three-dimensional (3d) can be measured by gel dosimeters. materials and methods dosimetry was performed with and without a square shield (6×6 cm2 field). the energies were 4, 9, and 16 mev and phantom w...

OBJECTIVE(S) To evaluate the feasibility and acceptability of the Micralax applicator and of methyl cellulose placebo gel for use in vaginal microbicide clinical trials. DESIGN A two-centre prospective study following women for 2 months. SETTING Two primary health care clinics in South Africa. PATIENTS, PARTICIPANTS Female volunteers (n = 28) 18 years or older who were HIV negative and ha...

introduction magnetic fields are capable of altering the trajectory of electron beams andcan be used in radiation therapy.theaim of this study was to produce regions with dose enhancement and reduction in the medium. materials and methods the ndfeb permanent magnets were arranged on the electron applicator in several configurations. then, after the passage of the electron beams (9 and 15 mev va...

A gynaecological applicator consisting of a metallic intra-uterine tube with a plastic vaginal applicator and an HDR Ir-192 source have been simulated with MCNP5 (Monte Carlo code). A solid phantom has been designed to perform measurements around the applicator with radiochromic films. The isodose curves obtained are compared with curves calculated with the F4MESH tally of MCNP5 with a good agr...

PURPOSE Esteya and Valencia surface applicators are designed to treat skin tumors using brachytherapy. In clinical practice, in order to avoid errors that may affect the treatment outcome, there are two issues that need to be carefully addressed. First, the selected applicator for the treatment should provide adequate margin for the target, and second, the applicator has to be precisely positio...

BACKGROUND Bipolar radiofrequency ablation (RFA) can avoid complications such as thermal tissue damage, a possible consequence of monopolar RFA. However, basic studies about the dosage/effect relationship of bipolar systems are missing. This is systematic research on ex vivo beef livers to find which capacity parameters produce high energy in the tissue and achieve large lesion volumes. MATER...

In this study, dose rate distribution around a spherical 137Cs pellet source, from a low-dose-rate (LDR) Selectron remote afterloading system used in gynecological brachytherapy, has been determined using experimental and Monte Carlo simulation techniques. Monte Carlo simulations were performed using MCNP4C code, for a single pellet source in water medium and Plexiglas, and measurements were pe...

introduction: brachytherapy is a type of radiotherapy in which radioactive sources are used in proximity of tumors normally for treatment of malignancies in the head, prostate and cervix. materials and methods: the cs-137 selectron source is a low-dose-rate (ldr) brachytherapy source used in a remote afterloading system for treatment of different cancers. this system uses active and inactive sp...

A novel phantom is presented for 'full system' dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film d...