The current state of the art in cancer treatment by radiation optimizes beam intensity spatially such that tumors receive high dose radiation whereas damage to nearby healthy tissues is minimized. It is common practice to deliver the radiation over several weeks, where the daily dose is a small constant fraction of the total planned. Such a 'fractionation schedule' is based on traditional model...

Aberration-corrected electron microscopy can resolve the smallest atomic bond-lengths in nature. However, high-convergence angles that enable spectacular resolution 2D have unknown 3D limits for all but objects ($< \sim$8nm). We show aberration-corrected tomography offers new imaging by measuring several focal planes at each specimen tilt. present a theoretical foundation establishing analytic ...

Ionizing radiation causes degeneration of myelin, the insulating sheaths of neuronal axons, leading to neurological impairment. As radiation research on the central nervous system has predominantly focused on neurons, with few studies addressing the role of glial cells, we have focused our present research on identifying the latent effects of single/ fractionated -low dose of low/ high energy r...

Total body irradiation (TBI) is a powerful but potentially hazardous tool used in the eradication of malignant cells and the suppression of the immune system to enable bone marrow engraftment. The occasion of its use is confined to bone marrow transplantation (BMT) in malignant disorders and some non-malignant haematological and metabolic conditions and is accompanied by high dose chemotherapy....

External beam radiation therapy with conventional fractionation to a total dose of 76-80 Gy represents the most adopted treatment modality for prostate cancer. Dose escalation in this setting has been demonstrated to improve biochemical control with acceptable toxicity using contemporary radiotherapy techniques. Hypofractionated radiotherapy and stereotactic body radiation therapy have gained a...

BACKGROUND Radiotherapy treatment after keloidectomy is known to be an effective method for reducing the rate of recurrence. However, to date, the appropriate total radiation dose and fractionation have not yet been confirmed. The authors performed a retrospective analysis to identify the appropriate radiation dose and fractionation in post-keloidectomy radiotherapy. METHODS From May 2000 to ...

Total body irradiation (TBI) is a powerful but potentially hazardous tool used in the eradication of malignant cells and the suppression of the immune system to enable bone marrow engraftment. The occasion of its use is confined to bone marrow transplantation (BMT) in malignant disorders and some non-malignant haematological and metabolic conditions and is accompanied by high dose chemotherapy....

Re-irradiation tolerance of the spinal cord depends upon the volume of the spinal cord irradiated, the total dose, the dose per fractional, the elapsed time between the treatments and the region of the spinal cord involved. Clinical data on the retreatment tolerance of the spinal cord are sparse and inconclusive. Radiobiological laboratory evidence has indicated the presence of long term recove...

Spatiotemporally integrated fractionation involves finding a fluence-map and a number of treatment sessions that maximize tumor-kill subject to dose-limits on organs-at-risk (OAR). This problem was recently formulated using the linear-quadratic dose-response model. Owing to the uncertainty in dose-response parameters, however, a solution presumed optimal might be infeasible in practice. We addr...

The purpose of the present study was to investigate the threshold dose for focal liver damage after stereotactic body radiation therapy (SBRT) in cirrhotic and normal livers using magnetic resonance imaging (MRI). A total of 64 patients who underwent SBRT for liver tumors, including 54 cirrhotic patients with hepatocellular carcinoma (HCC) and 10 non-cirrhotic patients with liver metastases, we...