The Characteristics and Significances of Incidental Focal Uptake by PET-CT in the Thyroid Gland / 대한내분비외과학회지

PURPOSE: The increased use of positron emission tomography-computed tomography (PET-CT) has resulted in increased detection of incidentally found thyroid lesions. The purpose of this study was to determine the clinical significance of incidental PET-CT uptake in the thyroid and the characteristics of malignant thyroid lesions. METHODS: A retrospective review was conducted on the patients who were incidentally found to have abnormal uptake of thyroid on PET-CT. The patients' records were assessed for the demographics, the PET-CT findings, the standard uptake values (SUVmax), the ultrasonography findings, the fine needle aspiration (FNA) cytology and the surgical pathologic findings. RESULTS: One hundred-ten (4.0%) individuals were identified to have focal (n=35) or diffuse (n=75) thyroid uptake. Thyroid ultrasonography was performed on 29 patients with 35 focal thyroid uptakes, and there was no correlation between the mass size on ultrasonography and the SUVmax on PET-CT. The cytologic diagnosis was available for 26 patients and in 16 (61.53%) patients, the nodule was found to be malignant. The mean and standard deviation of the SUVmax was 5.21±4.08 for the malignant nodules and 8.78±7.32 for the benign nodules. There was no significant difference in the SUVmax between the benign and malignant nodules. CONCLUSION: In our study, focal thyroid uptakes incidentally found on PET-CT had a high risk of thyroid malignancy (55.17%). There seems to be no correlation between the SUVmax of the lesion and the risk of malignancy.

Results of Radiotherapy in Hypopharyngeal Cancer / 대한방사선종양학회지

PURPOSE: The aim of this study was to assess the effectiveness, survival rate and complications of radiation therapy and chemoradiation treatment in hypopharyngeal cancer. METHODS AND MATERIALS: From January 1984 to December 1999, 56 patients who had hypopharyngeal carcinoma treated with curative radiation therapy were retrospectively studied. Twenty four patients (42.9%) were treated with radiation therapy alone (Group I) and 32 (57.1%) treated with a combination of chemotherapy and radiation (Group II). Total radiation dose ranged from 40.5 to 83. 5 Gy (median 67.9 Gy). Radiotherapy was given with conventional technique in 9 patients (16.4%), with hyperfractionation I (1.15~1.2 Gy/fr., BID) in 26 (47.2%), hyperfractionation II (1.35 Gy/fr., BID) in 18 (32.7%), and accelerated fractionation (1.6 Gy/fr., BID) in 2 (3.6%). In chemotherapy, 5-FU (1,000 mg/m2 daily for 5 consecutive days) and cisplatin (100 mg/m2 on day 1) were administered in a cycle of 3 weeks interval, and a total of 1 to 3 cycles (average 2..3 cycles) were given prior to radiation therapy. Follow up duration was 1~195 months (median 28 months). RESULTS: Overall 2 and 5 year survival rates were 40.6% and 27.6%; 50.0% and 30.0% in Group I, and 36.4% and 26.3% in Group II, respectively. Complete local control rates in Group I and II were 70.0% and 67.7%, respectively. The response to radiotherapy and nodal stage were statistically significant prognostic factors. The complication rate was increased in Group II and was decreased in hyperfractionation. CONCLUSION: The response to radiotherapy and nodal stage were valid factors to indicate the degree of control over the hypopharyngeal cancer. The induction cisplatin, 5-Fu chemotherapy was not valid in terms of local control rate and survival rate, but did contribute to an increased complication rate. The use of hyperfractionation was valid to reduce the late radiation complications.

Detection of Extended-spectrum beta-Lactamase-producing Escherichia coli and Klebsiella spp. with the Vitek GNS 121 Card / 대한임상병리학회지

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp. isolates are clinically resistant to all the beta-lactams except for carbapenems. The most important task facing clinical microbiologists today is the reliable detection of ESBL-producing microorganisms. There is currently a little reliable methods designed specifically for the detection of ESBLs in isolates of E. coli and Klebsiella spp. that can be performed easily in a clinical laboratory. This study was designed to evaluate the ability of the Vitek GNS 121 card to detect the ESBL-producing E. coli and Klebsiella spp. METHODS: One hundred and twenty-two isolates of E. coli, 141 of K. pneumoniae, and 3 of K. oxytoca from patients of the Kosin Medical Center, Pusan, Korea were tested. Antimicrobial susceptibilities were tested by the disk diffusion method. And the double disk synergy (DDS) test and the Vitek GNS 121 card determined the ESBL-production. RESULTS: Among the 135 DDS-positive isolates (K. peumoniae, 104; E. coli, 28; K. oxytoca, 3), 131 isolates (K. pneumoniae, 103; E. coli, 25; K. oxytoca, 3) showed positive results with the Vitek GNS 121 card as well. And all the isolates of K. pneumoniae (37) and E. coli (94) showed negative results with both the DDS test and the Vitek GNS 121 card except for 1 isolate of E. coli. The Vitek GNS 121 card showed 97% ESBL detection-sensitivity, 99% specificity and 99% positive predictive value. Three isolates of E. coli and 1 of K. pneumoniae resistant to cefoxitin showed positive results with the DDS test but showed negative results with the Vitek GNS 121 card. CONCLUSIONS: The Vitek GNS 121 card seems to be adequate for routine use in the detection of ESBL-producing isolates of E. coli and Klebsiella in clinical microbiology laboratories. Also, additional evaluation should be taking place on its detection ability for other members of the ESBL-producing Enterobacteriaceae.

Antimicrobial Susceptibilites of Glycopeptides, Arbekacin and Quinupristin/Dalfopristin against Staphylococcal aureus isolates / 감염

No abstract available.

The Frequency of Chromosomal Aberrations of Peripheral Lymphocytes according to Radiation Dose and Dose Rate / 대한방사선종양학회지

PURPOSE: It was studied that the relationship between radiation dose, dose rate and the frequency of chromosomal aberrations in peripheral lymphocytes. METHODS AND MATERIALS: Peripheral lymphocytes were irradiated in vitro with 6 MeV X-ray at dose ranges from 50 cGy to 800 cGy. The variations of the frequency of chromosomal aberrations were observed according to different radiation dose rate from 20 cGy/min to 400 cGy/min at constant total dose of 400 cGy which it was considered as factor to correct biological radiation dose measurement. RESULTS: The yields of lymphocytes with chromosomal aberrations (dicentric chromosome, ring chromosome, acentric fragment pairs) are 0% at 50 cGy, 9% at 100 cGy, 20% at 200 cGy, 27% at 300 cGy, 55% at 400 cGy, 88% at 600 cGy, and 100% at 800 cGy. The value of Ydr is 0.000 at 50 cGy, 0.093 at 100 cGy, 0.200 at 200 cGy, 0.364 at 300 cGy, 0.612 at 400 cGy, 2.040 at 600 cGy, and 2.846 at 800 cGy. The relationship between radiation (D) and the frequency of dicentric chromosomes and ring chromosomes (Ydr) can be expressed as Ydr=0.188x10-2/GyxD+0.422x10-4/Gy2xD2. The value of Qdr is 0.000 at 50 cGy, 1.000 at 100 cGy, 1.000 at 200 cGy, 1.333 at 300 cGy, 1.118 at 400 cGy, 2.318 at 600 cGy, and 2.846 at 800 cGy. When 400 cGy is irradiated with different dose rate each of 20, 40, 60, 80, 100, 160, 240, 320, and 400 cGy/min, Ydr is each of 0.982, 0.837, 0.860, 0.732, 0.763, 0.966, 0.909, 1.006, and 0.806, and Qdr is each of 1.839, 1.565, 1.654, 1.333, 1.381, 1.750, 1.6000, 1.710, and 1.318. CONCLUSION: There are not the significant variations of Ydr and Qdr values according to different dose rate. And so radiation damage is influenced by total exposed radiation doses and is influenced least of all by different dose rate when it is acute single exposure.

The Analysis of Radiation Exposure of Hospital Radiation Workers / 대한방사선종양학회지

PURPOSE: This investigation was performed in order to improve the health care of radiation workers, to predict a risk, to minimize the radiation exposure hazard to them and for them to realize radiation exposure danger when they work in radiation area in hospital. METHODS AND MATERIALS: The documentations checked regularly for personal radiation exposure in four university hospitals in Pusan city in Korea between January 1, 1993 and December 31, 1997 were analyzed. There were 458 persons in this documented but 111 persons who worked less then one year were excluded and only 347 persons were included in this study. RESULTS: The average of yearly radiation exposure of 347 persons was 1.52+/-1.35 mSv. Though it was less than 50mSv, the limitaion of radiation in law but 125 (36%) people received higher radiation exposure than non-radiation workers. Radiation workers under 30 year old have received radiation exposure of mean 1.87+/-1.01 mSv/year, mean 1.22+/-0.69 mSv between 31 and 40 year old and mean 0.97+/-0.43 mSv/year over 41year old ( p<0.001). Men received mean 1.67+/-1.54 mSv/year were higher than women who received mean 1.13+/-0.61 mSv/year ( p<0.01). Radiation exposure in the department of nuclear medicine department in spite of low energy sources is higher than other departments that use radiations in hospital ( p<0.05). And the workers who received mean 3.69+/-1.81 mSv/year in parts of management of radiation sources and injection of sources to patient receive high radiation exposure in nuclear medicine department ( p<0.01). In department of diagnostic radiology high radiation exposure is in barium enema rooms where workers received mean 3.74+/-1.74 mSv/year and other parts where they all use fluoroscopy such as angiography room of mean 1.17+/-0.35 mSv/year and upper gastrointestinal room of mean 1.74+/-1.34 mSv/year represented higher radiation exposure than average radiation exposure in diagnostic radiology ( p<0.01). Doctors and radiation technologists received higher radiation exposure of each mean 1.75+/-1.17 mSv/year and mean 1.60+/-1.39 mSv/year than other people who work in radiation area in hospital ( p<0.05). Especially young doctors and technologists have the high opportunity to receive higher radiation exposure. CONCLUSION: The training and education of radiation workers for radiation exposure risks are important and it is necessary to rotate worker in short period in high risk area. The hospital management has to concern health of radiation workers more and to put an effort to reduce radiation exposure as low as possible in radiation areas in hospital.