ABSTRACT
The quality of portal imaging is strongly affected by the source size of the radiotherapy machine. The effective source size of the dual-energy clinac 1800 (6 and 18 MV) was measured with a 50 microns wide and 120 mm long slit formed by two tungsten-copper alloy blocks. A series of slit images were obtained by translating the slit horizontally. The images were analyzed using a microdensitometer. The measured data was simulated using an analytical model of the source and its size was derived by a best-fit analysis. For both energies the FWHM was found to be 1.5 +/- 0.1 mm.
Subject(s)
Radiotherapy/methods , Humans , Mathematics , Models, Theoretical , Radiotherapy/instrumentation , Radiotherapy Dosage , X-RaysABSTRACT
Between 1976 and 1983, 28 patients with Kaposi's sarcoma were treated in the Department of Radiation and Clinical Oncology of the Hadassah University Hospital in Jerusalem. Most of the patients (16, i.e. 57%) were Jews of European origin. Eighteen (64.2%) of the patients presented with severe leg edema in addition to multifocal, disseminated skin lesions. Only one patient was free of clinical disease in the lower extremities. Large, ulcerated masses were seen in three patients. The affected limbs were immersed in a water bath and irradiated with two-opposing portals to a total dose of 3000 rads. Total disappearance of the skin lesions was achieved in 89% of the patients, although the limb edema regressed completely in only 56% of the patients.
Subject(s)
Radiotherapy, High-Energy/instrumentation , Sarcoma, Kaposi/radiotherapy , Skin Neoplasms/radiotherapy , Water , Adult , Aged , Aged, 80 and over , Female , Humans , Immersion , Male , Middle AgedABSTRACT
A relationship between the structure of the sclera and its light scattering properties is proposed. The relative optical density as a function of wavelength in the infrared was measured for three sclera and a good correlation with the predicted function was found. The angular distribution of the scattered light at 632.8 nm as well as the degree of polarisation of the scattered light at zero angle was measured for three sclera; from these results the total transmission of the sclera was determined.
Subject(s)
Sclera/physiology , Collagen/metabolism , Humans , Light , Models, Biological , Optics and Photonics , Scattering, RadiationABSTRACT
The density of cancellous bone in the nondominant radius of healthy subjects has been observed by the Compton scattering method as a function of age and sex. The average density for males is higher than for females. In males the density does not change up to the age of 80 years, while in females the density decreases beginning at age 50. A significant decrease in the bone mineral content of the distal radius is observed at earlier ages as measured by the Cameron-Sorenson technique. The average value of the cortical index of the third metacarpal shows some difference between the sexes over the age of 50, the index in males being higher than in the females. Between 30 and 50 years the female cortical index is greater than in the males. Little correlation was found among the three parameters studied, suggesting that they measure different phases of the pathophysiological processes involved in aging bone.
Subject(s)
Aging , Bone and Bones/metabolism , Densitometry/methods , Minerals/metabolism , Adult , Age Factors , Aged , Bone and Bones/analysis , Female , Humans , Male , Middle Aged , Minerals/analysis , Osteoporosis/metabolism , Radius/analysis , Reference Values , Sex Factors , Spectrometry, GammaABSTRACT
THe concentration of copper, zinc and iron in the skin of patients suffering from lepra reaction was measured by diagnostic X-ray spectrometry (DXS) at the sites of the lesions before and after treatment with thalidomide. The results were compared with the levels of these elements in the skin of healthy individuals. No significant changes in the copper level of leprous skin were found. The zinc levels showed significant elevations in some lesions with no apparent trend. The iron level in the affected areas had highly elevated values in all cases of lepra reaction. However, in contrast to the fast clinical improvement which followed the treatment with thalidomide, the iron levels did not decrease for prolonged periods.
Subject(s)
Iron/metabolism , Leprosy/drug therapy , Skin/metabolism , Thalidomide/therapeutic use , Adult , Copper/metabolism , Female , Humans , Male , Middle Aged , Spectrometry, X-Ray Emission , Zinc/metabolismABSTRACT
The concentration of iron, cooper and zinc in the skin of patients with prurigo nodularis was measured by diagnostic X-ray spectrometry before and after treatment with thalidomide. Before treatment, larger skin lesions were associated with significantly higher zinc levels and higher iron levels than the smaller ones. Upon treatment the zinc and iron content in these lesions decreased towards normal range. Copper values were found to be within the normal range in lesions before and after thalidomide treatment.
Subject(s)
Prurigo/metabolism , Skin/metabolism , Thalidomide/therapeutic use , Adult , Copper/metabolism , Female , Humans , Iron/metabolism , Male , Middle Aged , Prurigo/drug therapy , Spectrometry, X-Ray Emission , Zinc/metabolismABSTRACT
A new approach is suggested for the management of nonmagnetic intraocular foreign bodies. This approach is based on diagnostic x-ray spectrometry, which is capable of detecting noninvasively the dissolution of metallic intraocular foreign bodies. As long as no copper dissolution is observed, foreign bodies of reasonable size are left in the eye and extraction is recommended whenever a persisting copper dissolution is detected. Of the 32 patients examined and followed up, 23 did not show any copper dissolution. The majority of these patients, one of whom has retained a foreign body for 28 years, have satisfactory visual functions. Of the nine patients in whom copper dissolution was observed, five were operated on. In three of the remaining four patients, the operation was delayed and the dissolution was found to be temporary. These patients retained good visual functions.
Subject(s)
Eye Foreign Bodies/therapy , Adolescent , Adult , Child , Copper , Electroretinography , Eye Foreign Bodies/diagnosis , Eye Foreign Bodies/surgery , Humans , Male , Middle Aged , Spectrometry, X-Ray EmissionABSTRACT
The density of the distal end of the radius is one of the parameters used to determine the presence and degree of osteoporosis in patients. In this work the bone density has been determined by measuring the intensity of the Compton scattered photons, since this is proportional to the absolute density of the scatterer, in materials for which Z/A is constant. A collimated beam from a 500 mCi 137Cs source was used and the intensity of the scattered radiation measured at an angle of 90 degrees. The exact point of measurement was determined by a two-dimensional scanning technique. A plastic water phantom was used to calculate the correction needed for absorption and backscatter by the surrounding tissue. Bone density was measured by this method in 50 subjects. A good correlation was found between density of the radius and the degree of morphological change in the vertebrae. In a number of cases a low bone density was discovered without signs of osteoporosis in the spine. These findings were considered indicative of early osteoporotic change, not definable by routine X-ray techniques. This technique may be of value in the follow-up of patients and in controlling the effect of various treatment schedules.
Subject(s)
Osteoporosis/diagnosis , Aged , Densitometry/methods , Female , Humans , Male , Middle Aged , Radius , Scattering, Radiation , Spectrometry, GammaABSTRACT
X-ray spectrometry appears to be a reliable and safe method for noninvasive detection and measurement of metals in the eye for clinical and experimental purposes. Preliminary results in rabbits show that the dissolution of small copper intraocular foreign bodies can be detected shortly after their implantation. The dissolution was measured repeatedly and described as a function of time. It is hoped that this method can supply data regarding the nature and the extent of dissociation of intraocular foreign bodies, thus supplementing methods which can give information regarding only their presence and location.
Subject(s)
Copper/analysis , Eye Foreign Bodies/diagnosis , Eye/analysis , Spectrometry, Fluorescence/methods , Animals , Copper/adverse effects , Foreign-Body Reaction/diagnosis , Platinum/analysis , Rabbits , Retina/analysis , Spectrometry, Fluorescence/instrumentation , Vitreous Body/analysisABSTRACT
The binding property of ionic indium (In3+) with plasma transferrin was utilized for determination of plasma volumes (PV) of whole body and individual organs in small animals. Plasma transferrin from a donor rat was labeled with 15-17 muCi 113mIn/ml plasma and injected into the tested rats. PV were determined either by extrapolation to the dilution at time zero (for whole animals) or by calculation of the ratio, organ radiation: radiation of a plasma unit volume (for organs). The reliability of the method for determination of whole-body PV was ascertained by comparing the results obtained with those obtained simultaneously by the Evans blue dilution method. Whole body PV values obtained by the two methods were similar, with a correlation coefficient (r) of 0.997. The short half life of 113mIn enables it to be used with other nuclides which have similar or different energies in the same sample; indium radiation was counted first and after it had disappeared the activity of the other nuclide could be measured.
