The potential of an oxygen-carrying perfluorochemical emulsion (PFCE) to enhance radiation damage in Lewis lung tumor growing in C57BL/6J X DBA/2J F1 mice was examined. PFCE and 95% O2:5% CO2 (carbogen) breathing caused a significant enhancement of single-fraction radiation damage measured by the growth delay assay. The dose-response effect of PFCE was very broad; doses as small as 0.5 ml/mouse...

MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd)-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitati...

This study investigated radiation dose variations in pre-clinical irradiation due to the photon beam energy and presence of tissue heterogeneity. Based on the same mouse computed tomography image dataset, three phantoms namely, heterogeneous, homogeneous and bone homogeneous were used. These phantoms were generated by overriding the relative electron density of no voxel (heterogeneous), all vox...

Presence of interfaces between high and low atomic number (Z) materials, often encountered in diagnostic imaging and radiation therapy, leads to radiation dose perturbation. It is characterized by a very narrow region of sharp dose enhancement at the interface. A rapid falloff of dose enhancement over a very short distance from the interface makes the experimental dosimetry nontrivial. We use a...

Objective of the study: To explore the potential for therapeutic gain with gold nanoparticles in arteriovenous malformation radiosurgery based on their interaction with photons and protons. Study methods: Radiation dose enhancement resulting from the interaction of gold nanoparticles with irradiation ranging from kilovoltage to megavoltage photons and protons was researched in the literature. T...

We have calculated the dose enhancements close to metal implants in Gamma Knife radiosurgery using different beam sizes, i.e., 4, 8 and 18 mm collimator helmets sin addition to the previous calculations using the 14 mm collimator helmetd. For the 8 and 18 mm helmets, the obtained results were similar to those obtained using the 14 mm helmet, which can be explained by the similar beam profiles w...

The effect of hyperglycemia on the cytotoxic effect of a chemotherapeutic agent was studied at elevated temperature. The seventh generation of a spontaneous C3Hf/Sed mouse fibrosarcoma, FSa-II, was transplanted into the footpads of the same strain of mice. Hyperthermia was given by immersing animal feet into a water bath where 41.5 +/- 0.1 degrees (range) was maintained by a constant temperatur...

Ionizing radiation is known for its cytotoxic and mutagenic properties. However, recent evidence suggests that chronic sub-lethal irradiation stimulates the growth of melanin-pigmented (melanized) fungi, supporting the hypothesis that interactions between melanin and ionizing photons generate energy useful for fungal growth, and/or regulate growth-promoting genes. There are no quantitative mode...

Background: Gold nanoparticles (GNPs) have been shown as a good radiosensitizer. In combination with radiotherapy, several studies with orthovoltage X-rays have shown considerable dose enhancement effects. This paper reports the dose enhancement factor (DEF) due to GNPs in 18 megavoltage (MV) beams. Materials and Methods: Different geometrical 50-nm GNPs configurations at a concentrati...

– gafchromic xrct radiochromic film is a self developing high sensitivity radiochromic filmproduct which can be used for assessment of delivered radiation doses which could match applications suchas computed tomography (ct) dosimetry. the dose response of gafchromic xrct radiochromic film hasbeen measured with reflectance spectrophotometry and desktop scanners. the film automatically changescol...