The three-dimensional scintillation dosimetry method: test for a 106Ru eye plaque applicator.

The need for fast, accurate and high resolution dosimetric quality assurance in radiation therapy has been outpacing the development of new and improved 2D and 3D dosimetry techniques. This paper summarizes the efforts to create a novel and potentially very fast, 3D dosimetry method based on the observation of scintillation light from an irradiated liquid scintillator volume serving simultaneously as a phantom material and as a dose detector medium. The method, named three-dimensional scintillation dosimetry (3DSD), uses visible light images of the liquid scintillator volume at multiple angles and applies a tomographic algorithm to a series of these images to reconstruct the scintillation light emission density in each voxel of the volume. It is based on the hypothesis that with careful design and data processing, one can achieve acceptable proportionality between the local light emission density and the locally absorbed dose. The method is applied to a Ru-106 eye plaque immersed in a 16.4 cm3 liquid scintillator volume and the reconstructed 3D dose map is compared along selected profiles and planes with radiochromic film and diode measurements. The comparison indicates that the 3DSD method agrees, within 25% for most points or within approximately 2 mm distance to agreement, with the relative radiochromic film and diode dose distributions in a small (approximately 4.5 mm high and approximately 12 mm diameter) volume in the unobstructed, high gradient dose region outside the edge of the plaque. For a comparison, the reproducibility of the radiochromic film results for our measurements ranges from 10 to 15% within this volume. At present, the 3DSD method is not accurate close to the edge of the plaque, and further than approximately 10 mm (<10% central axis depth dose) from the plaque surface. Improvement strategies, considered important to provide a more accurate quick check of the dose profiles in 3D for brachytherapy applicators, are discussed.

Isolated pemphigus vegetans of the tongue.

Pemphigus vegetans affecting only the tongue is reported in a 35-year-old woman.

Silicone gel sheet dressings for prevention of post-minigraft cobblestoning in vitiligo.

Punch grafting was performed in 15 patients using punches varying in size from 2 to 3 mm in diameter. Silicone gel sheets were used as a post-operative dressing. Removal of the dressings after 7 days revealed no lifting of grafts in 13 patients. A minimally raised surface seen in two patients flattened after 6 to 8 weeks of continuous use of the dressing. At two months of follow-up, no cobblestoning or any other untoward effect was evident. Firm pressure provided by silicone gel sheets probably prevents cobblestoning by counteracting forces which tend to lift the grafts. Additionally, the sheets act as a brace preventing graft dislocation, provide a sterile atmosphere underneath the grafts, facilitate periodic observation due to their transparency, and are easily removed at the time of follow-up.

Trichotillomania in a 2-year-old child.

A case report of a 2-year-old child with trichotillomania is described.

Chloroquine-induced toxic epidermal necrolysis.

Two female patients aged 25 and 12 years suffering from malaria presented with picture of Stevens Johnson syndrome. Each of them had received daily doses of chloroquine phosphate by intramuscular injection for 3 days. They progressed to toxic epidermal necrolysis and could not be saved despite best of efforts.

Livedo reticularis with acute rheumatic fever.

A 10-year-old boy, a diagnosed case of acute rheumatic fever, presented with livedo reticularis involving whole of body except face. Livedo reticularis has been very rarely reported in rheumatic fever.