The mean lung dose (MLD) : predictive criterion for lung damage?

Aim: The purpose of this work was to prove the validity of the mean lung dose (MLD), widely used in clinical practice to estimate the lung toxicity of a treatment plan, by reevaluating experimental data from mini pigs.

Materials And Methods: A total of 43 mini pigs were irradiated in one of four dose groups (25, 29, 33, and 37 Gy). Two regimens were applied: homogeneous irradiation of the right lung or partial irradiation of both lungs-including parts with lower dose-but with similar mean lung doses.

Triple angiokinase inhibition, tumour hypoxia and radiation response of FaDu human squamous cell carcinomas.

Background And Purpose: To test the effect of BIBF 1120, a novel small molecule inhibitor of multiple angiogenic receptor tyrosine kinases, on the hypoxia and radiation response of tumours.

Materials And Methods: Poorly differentiated human squamous cell carcinoma FaDu growing in nude mice was treated with BIBF 1120 and investigated by functional histology. To test the effect of BIBF 1120 on the radiobiological hypoxic fraction (rHF), the number and intrinsic radiation sensitivity of tumour stem cells and the outcome after fractionated irradiation, a series of local tumour control assays were performed.

Inactivation of AP1 proteins by a nuclear serine protease precedes the onset of radiation-induced fibrosing alveolitis.

Radiation-induced lung damage comprises inflammation (alveolitis) as well as disturbed regulation of cell differentiation and proliferation (fibrosis). The transcriptional regulation of this process is poorly understood. One key transcription factor involved in the regulation of proliferation and differentiation is AP1 (activator protein 1).

Expression of the immunomodulator IL-10 in type I pneumocytes of the rat: alterations of IL-10 expression in radiation-induced lung damage.

Fibrosing alveolitis is a disease with inflammatory, proliferative, and fibrotic components. In different models, it has been shown that the cytokine interleukin-10 (IL-10) plays a conflicting role in inflammation-associated fibrotic processes, inasmuch as it is an anti-inflammatory cytokine but also a TH2 cytokine with inherent pro-fibrotic effects. IL-10 is produced primarily by inflammatory cells.

Filmless evaluation of the mechanical accuracy of the isocenter in stereotactic radiotherapy.

Background And Purpose: The Winston-Lutz test verifies the mechanical accuracy of the isocenter in stereotactic radiotherapy. A lead ball inside a small beam is exposed to film applying different combinations of the gantry angle and the table angle. The increasing replacement of films by digital images requires alternative imaging methods.

Portal verification using the KODAK ACR 2000 RT storage phosphor plate system and EC films. A semiquantitative comparison.

Background And Purpose: The suitability of the storage phosphor plate system ACR 2000 RT (Eastman Kodak Corp., Rochester, MN, USA), that is destined for portal verification as well as for portal simulation imaging in radiotherapy, had to be proven by the comparison with a highly sensitive verification film.

Material And Methods: The comparison included portal verification images of different regions (head and neck, thorax, abdomen, and pelvis) irradiated with 6- and 15-MV photons and electrons.

Portal verification of high-energy electron beams using their photon contamination by film-cassette systems.

Background And Purpose: Though electron beams are widely used in radiotherapy, their verification is not well established in clinical practice. The present study compares the suitability of several sensitive film-cassette systems for electron-portal verification by contaminating photons.

Material And Methods: The characteristics of the optical density curves of film-cassette combinations were determined by exposing them to the bremsstrahlung contamination of a variety of electron beams.

Enhanced susceptibility of irradiated tumor vessels to vascular endothelial growth factor receptor tyrosine kinase inhibition.

Previous experiments with PTK787/ZK222584, a specific inhibitor of vascular endothelial growth factor receptor (VEGFR) tyrosine kinases, using irradiated human FaDu squamous cell carcinoma in nude mice, suggested that radiation-damaged tumor vessels are more sensitive to VEGFR inhibition. To test this hypothesis, the tumor transplantation site (i.e.

Solution structure of the Ran-binding domain 2 of RanBP2 and its interaction with the C terminus of Ran.

The termination of export processes from the nucleus to the cytoplasm in higher eukaryotes is mediated by binding of the small GTPase Ran as part of the export complexes to the Ran-binding domains (RanBD) of Ran-binding protein 2 (RanBP2) of the nuclear pore complex. So far, the structures of the first RanBD of RanBP2 and of RanBP1 in complexes with Ran have been known from X-ray crystallographic studies. Here we report the NMR solution structure of the uncomplexed second RanBD of RanBP2.

In vivo verification of electron beam energy by patient exit dose and optical density of portal films.

Background And Purpose: The depth-dose curve of electron beams is mainly determined by their energy. For accelerators with scatter foils, the electron energy can, in principle, be verified by measuring the amount of the contaminating photons. This paper investigates whether exit dose measurements and evaluations of the optical density of portal films can be used to verify the energy of the electron beam in a clinically relevant setting.