Measurement of photoneutron dose produced by wedge filters of a high energy linac using polycarbonate films.

Radiotherapy represents the most widely spread technique to control and treat cancer. To increase the treatment efficiency, high energy linacs are used. However, applying high energy photon beams leads to a non-negligible dose of neutrons contaminating therapeutic beams.

The effect of field modifier blocks on the fast photoneutron dose equivalent from two high-energy medical linear accelerators.

High-energy linear accelerators (linacs) have several advantages, including low skin doses and high dose rates at deep-seated tumours. But, at energies more than 8 MeV, photonuclear reactions produce neutron contamination around the therapeutic beam, which may induce secondary malignancies. In spite of improvements achieved in medical linac designs, many countries still use conventional (non-intensity-modulated radiotherapy) linacs.

Echinococcus granulosus: lethal effect of low voltage direct electric current on hydatid cyst protoscoleces.

We have studied a small scale method for killing hydatid cyst protoscoleces using low voltage direct electric current. After collecting hydatid cysts from infected organs of slaughtered animals, protoscoleces were cultured in four different media: hydatid cyst fluid, RPMI, normal saline, and Tris buffer, respectively. Protoscoleces from each of the above media were then transferred to an electrolysis device through which different electric current densities were applied.

Pulmonary nodules: effect on detection of spiral CT pitch.

Purpose: To compare spiral computed tomography (CT) performed at increased pitch with spiral CT performed at standard pitch in the detection of pulmonary nodules.

Materials And Methods: Spiral CT scanning of the thorax was performed with a pitch of 1.0 in 109 patients with pulmonary nodules due to metastases.

Comparison of spiral-acquisition computed tomography and conventional computed tomography in the assessment of pulmonary metastatic disease.

In a prospective study, spiral-acquisition computed tomography (SACT) of the thorax was evaluated in 104 patients with extrathoracic malignancy and suspected pulmonary metastases, and was directly compared with conventional computed tomography (CCT) in 23 patients. The following parameters were assessed: lesion detectability; the effect on lesion detectability of reconstruction of scans at 5 mm and 10 mm slice increments; breathing artefact and slice misregistration. The radiation dose of the two techniques was measured using thermoluminescent dosimeters placed within an anthropomorphic chest phantom, and the visibility of simulated metastases inserted into the phantom was also compared using CCT, standard SACT and SACT with pitch greater than 1.