Characterization of small radiophotoluminescence dosemeter in terms of HP(0.07) for extremity dose monitoring of medical personnel.

An additional extremity monitoring using a ring badge must be appropriately conducted for inhomogeneous exposure around radiation workers' extremity. Commercially available glass dosemeters are characterized in terms of Hp(0.07) for the application of additional extremity monitoring. A series of experiments demonstrated that the response of the model GD-352M radiophotoluminescence dosemeter fully matched the IEC's criteria for an extremity dosemeter for medical personnel. Although the model GD-302M has excellent angular dependence, the material and the shape of energy compensation filter still need to be optimized to improve its energy dependence in the range between 30 and 100 keV. The combine use of both types of glass dosemeters for 'paired dosemeter' together with introduction of a simple algorithm may be a promising method to improve the response in the energy range below 20 keV.

Effects of glycine betaine on bone marrow death and intestinal damage by gamma rays and carbon ions.

In this study, we investigated the effects of glycine betaine (GB) on bone marrow death and intestinal damage by gamma rays or carbon ions. C(3)H/He female mice received an i.p.-injection of GB before or after whole-body irradiation with gamma rays or 50 keV microm(-1) carbon ions. The irradiated mice were observed to determine the mortality for 30 days after exposure. Mice were also killed at 3.5 days after the exposure to determine the intestinal damage. The numbers of crypts per transverse circumference were counted using a microscope. For the bone marrow death, GB (93 mg GB per mouse) significantly (p < 0.05) increased the percentage survival for both radiations. For the intestinal damage, GB (93 mg GB per mouse) significantly (p < 0.05) increased the crypt survival for gamma rays, but not for carbon ions. GB might be a potential protector against normal tissue damage as a side effect in radiotherapy.

Induction of superoxide in glioma cell line U87 stimulated with lipopolysaccharide and interferon-gamma: ESR using a new flow-type quartz cell.

The production of superoxide and nitric oxide induced in U87 glioma treated with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) was examined by electron spin resonance (ESR) spectroscopy using a newly designed flow-type quartz cuvette without detaching cells from the culture plate. ESR spectra of 2,2,6, 6-tetramethyl-4-hydroxy-1-piperidinyloxy (TEMPOL) with U87 cells on a quartz culture plate were measured at 15 min intervals. The signal intensity of TEMPOL decreased in the presence of U87 cells at the pseudo-first order rate. The signal decay was accelerated in the U87 cells treated with LPS/IFN-gamma for 24 h, and was suppressed in the presence of superoxide dismutase and catalase. By the spin-trapping method, nitric oxide from U87 cells pretreated with LPS/IFN-gamma for 24 h was measured by the ESR, but only a weak signal of nitric oxide adducts was detected. Further, the nitrite and nitrate levels in the medium did not increase for 24 h. By the ESR measurement of cells on culture plates without detachment stress, it was found that the production of superoxide was induced by LPS/IFN-gamma, but that of nitric oxide was not, in U87 glioma cells.

Cerebral radiation necrosis with accumulation of thallium 201 on single-photon emission CT.

A patient who had previously undergone resection of a malignant glioma followed by radiation therapy was found to have a focus of a high accumulation of thallous chloride Tl 201 on single-photon emission CT scans, suggesting recurrent tumor. Resection of this area was performed and the specimen showed radiation necrosis, including such reactive changes as reactive astrocytes and lymphocytes in the necrotic tissue. This case illustrates a diagnostic pitfall in the use of 201Tl single-photon emission CT for distinguishing radiation necrosis from recurrent tumor in patients treated for malignant glioma.

Interhemispheric subdural hematoma caused by a ruptured internal carotid artery aneurysm: case report.

BACKGROUND: Interhemispheric subdural hematoma (ISH) usually occurs after head trauma; nontraumatic ISH is extremely rare. CASE DESCRIPTION: The authors describe a 62-year-old male presenting with severe headache and ptosis on the left side. Computed tomography (CT) and magnetic resonance imaging disclosed a hematoma in the interhemispheric subdural space without subarachnoid hemorrhage. Cerebral angiography revealed an aneurysm arising from the left internal carotid-posterior communicating artery (IC-PC) junction. The patient underwent emergency clipping of the aneurysm and was discharged without neurological deficit. CONCLUSION: Ruptured aneurysms resulting in ISH without subarachnoid hemorrhage have been reported in only a few cases; this is the second case to describe the association of a ruptured IC-PC aneurysm with an ISH. The etiology of ISH formation due to ruptured aneurysms and the diagnosis are discussed.

Dose measurement for patients and physicians using a glass dosemeter during endovascular treatment for brain disease.

It has been reported that exposure of patients and physicians to radiation from interventional radiological procedures cannot be disregarded. Direct measurement of patient exposure used to be difficult due to possible interference by the detector with the observation of X ray images. Recently, a dosemeter system consisting of small-sized glass chips and a reader which adopts pulsed UV laser stimulation has been developed. Owing to its small size, radiolucency and physical characteristics, direct monitoring of surface dose has become feasible. Dose measurement for patients and physicians during neurointervention was done using the photoluminescence glass dosemeter system. The dose-response of the dosemeter was almost linear over a broad dose range, but its energy dependency was rather high without a filter, the use of which is recommended by the manufacturer to compensate for energy dependency. Variation of sensitivity of about 20% was observed for effective energies of 45-60 keV which are used in neurointervention. In spite of this shortcoming, the photoluminescence glass dosemeter system was judged to be a convenient means for monitoring dose during neurointervention.

Dose measurement on both patients and operators during neurointerventional procedures using photoluminescence glass dosimeters.

BACKGROUND AND PURPOSE: Although radiation skin injuries associated with interventional radiology have been known as a critical issue, there are few reports mentioning direct measurement of the entrance skin dose (ESD). Thus, the purpose of this study was to clarify the regional distributions of ESDs in neurointervention. MATERIALS AND METHODS: Using photoluminescence glass dosimeters (PLDs), we measured the ESDs in 32 patients with a median age of 61.5 years. Angiographic parameters, including exposure time, dose-area product (DAP), and the number of digital subtraction angiography (DSA) studies and frames, were recorded. The ESDs of operators were analyzed by the same method. RESULTS: The maximum ESD of 28 therapeutic procedures was 1.8 +/- 1.3 Gy. Although the averaged ESD on the right temporo-occipital region was higher than that in other regions, disease-specific patterns were not observed. Statistically positive correlations were found between the maximum ESD and exposure time (r = 0.5283, P = .005), DAP (r = 0.7917, P < .001), the number of DSA studies (r = 0.5636, P = .002), and the number of DSA frames (r = 0.8583, P < .001). As for operators, ESDs to the left upper extremity were significantly higher than those to other regions. However, most of the ESDs were <0.2 mGy. Lead protective garments reduced the exposure doses to approximately one half to one tenth. CONCLUSION: It was shown that the regional ESD could be measured by applying the PLD. This method should contribute to reducing the dose accumulation in patients as well as in operators.

alpha-Lipoic acid attenuates x-irradiation-induced oxidative stress in mice.

The development of nontoxic but effective radioprotectors is needed because of the increasing risk of human exposure to ionizing radiation. We have reported that alpha-lipoic acid confers considerable radio-protective effect in mouse tissues when given prior to x-irradiation. In the present study, alpha-lipoic acid supplementation prior to x-irradiation with 4 and 6 Gy significantly inhibited the radiation-induced decline in total antioxidant capacity (TAC) of plasma. Radiation-induced decline in non-protein sulfhydryl content (NPSH) of different tissues, namely, brain, liver, spleen, kidney, and testis, was also ameliorated significantly at both 4 and 6 Gy doses. Maximal augmentation of radiation-induced protein carbonyl content was observed in spleen followed by brain, kidney, testis, and liver. Maximal protection in terms of carbonyl content was observed in spleen (116%) at 6 Gy dose, and minimal protection was found in liver (22.94%) at 4 Gy dose. Maximal increase in MDA (malondialdehyde) content was observed in brain, followed by testis, spleen, kidney, and liver. Protection by alpha-lipoic acid pretreatment in terms of MDA content was maximal in brain (51.67%) and minimal in spleen. The findings support the idea that alpha-lipoic acid is a free-radical scavenger and a potent antioxidant.

Extracranial metastasis of anaplastic ganglioglioma through a ventriculoperitoneal shunt: a case report.

Extracranial metastasis of an intracranial anaplastic ganglioglioma through a ventriculoperitoneal shunt is reported. A 53-year-old woman was treated by surgery, radiation and chemotherapy and died 2 years later. At autopsy, multiple metastatic lesions were found in the spinal cord, and the abdominal and pleural cavities. Histologically, all the metastatic lesions were composed of atypical cells which resembled primitive glial elements found in intracranial anaplastic ganglioglioma, suggesting that anaplastic glial elements have a metastatic potential. Extracranial metastasis of ganglioglioma is a rare occurrence; however, the spread of glial elements through the shunt further suggests that caution is required in therapy and indicates a need for protective filters in the shunt system.

Correlation of histopathological factor of brain tumor and high thallium-201 uptake in single photon emission computed tomography.

This study was undertaken to investigate the relationship between several histological features and the degree of TI-201 uptake in brain tumors. T1-201 SPECT was performed on 52 patients with intracranial lesions. Histological examinations were carried out to determine the gradation of tumor cell density, vascularization, small-cell density, and matrix loosening, and the presence of necrosis, atypia, mitoses, and endothelial proliferation. The histological findings were classified into three categories. While the early uptake of T1-201 depended on the degree of necrosis of glial tumor, the delayed T1-201 uptake was closely related to the degree of necrosis, tumor cell density, and small-cell density, and may thus be of value for estimating the viability and degree of malignancy of glial tumors. In the non-glial tumors, the early and delayed T1-201 uptakes were closely related to all histological parameters, with the increase of necrosis and vascularization in the tumor tissue being particularly closely related to high uptake levels.