• Radiation Oncology Journal
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• v.23 no.3
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• pp.143-156
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• 2005

Background: The best dose-fractionation regimen of the definitive radiotherapy for cervix cancer remains to be clearly determined. It seems to be partially attributed to the complexity of the affecting factors and the lack of detailed information on external and intra-cavitary fractionation. To find optimal practice guidelines, our experiences of the combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) were reviewed with detailed information of the various treatment parameters obtained from a large cohort of women treated homogeneously at a single institute. Materials and Methods: The subjects were 743 cervical cancer patients (Stage IB 198, IIA 77, IIB 364, IIIA 7, IIIB 89 and IVA 8) treated by radiotherapy alone, between 1990 and 1996. A total external beam radiotherapy (EBRT) dose of $23.4\~59.4$ Gy (Median 45.0) was delivered to the whole pelvis. High-dose-rate intracavitary brachytherapy (HDR-IBT) was also peformed using various fractionation schemes. A Midline block (MLB) was initiated after the delivery of $14.4\~43.2$ Gy (Median 36.0) of EBRT in 495 patients, while In the other 248 patients EBRT could not be used due to slow tumor regression or the huge initial bulk of tumor. The point A, actual bladder & rectal doses were individually assessed in all patients. The biologically effective dose (BED) to the tumor ($\alpha/\beta$=10) and late-responding tissues ($\alpha/\beta$=3) for both EBRT and HDR-ICBT were calculated. The total BED values to point A, the actual bladder and rectal reference points were the summation of the EBRT and HDR-ICBT. In addition to all the details on dose-fractionation, the other factors (i.e. the overall treatment time, physicians preference) that can affect the schedule of the definitive radiotherapy were also thoroughly analyzed. The association between MD-BED $Gy_3$ and the risk of complication was assessed using serial multiple logistic regression models. The associations between R-BED $Gy_3$ and rectal complications and between V-BED $Gy_3$ and bladder complications were assessed using multiple logistic regression models after adjustment for age, stage, tumor size and treatment duration. Serial Coxs proportional hazard regression models were used to estimate the relative risks of recurrence due to MD-BED $Gy_{10}$, and the treatment duration. Results: The overall complication rate for RTOG Grades $1\~4$ toxicities was $33.1\%$. The 5-year actuarial pelvic control rate for ail 743 patients was $83\%$. The midline cumulative BED dose, which is the sum of external midline BED and HDR-ICBT point A BED, ranged from 62.0 to 121.9 $Gy_{10}$ (median 93.0) for tumors and from 93.6 to 187.3 $Gy_3$ (median 137.6) for late responding tissues. The median cumulative values of actual rectal (R-BED $Gy_3$) and bladder Point BED (V-BED $Gy_3$) were 118.7 $Gy_3$ (range $48.8\~265.2$) and 126.1 $Gy_3$ (range: $54.9\~267.5$), respectively. MD-BED $Gy_3$ showed a good correlation with rectal (p=0.003), but not with bladder complications (p=0.095). R-BED $Gy_3$ had a very strong association (p=<0.0001), and was more predictive of rectal complications than A-BED $Gy_3$. B-BED $Gy_3$ also showed significance in the prediction of bladder complications in a trend test (p=0.0298). No statistically significant dose-response relationship for pelvic control was observed. The Sandwich and Continuous techniques, which differ according to when the ICR was inserted during the EBRT and due to the physicians preference, showed no differences in the local control and complication rates; there were also no differences in the 3 vs. 5 Gy fraction size of HDR-ICBT. Conclusion: The main reasons optimal dose-fractionation guidelines are not easily established is due to the absence of a dose-response relationship for tumor control as a result of the high-dose gradient of HDR-ICBT, individual differences In tumor responses to radiation therapy and the complexity of affecting factors. Therefore, in our opinion, there is a necessity for individualized tailored therapy, along with general guidelines, in the definitive radiation treatment for cervix cancer. This study also demonstrated the strong predictive value of actual rectal and bladder reference dosing therefore, vaginal gauze packing might be very Important. To maintain the BED dose to less than the threshold resulting in complication, early midline shielding, the HDR-ICBT total dose and fractional dose reduction should be considered.

• Journal of dental hygiene science
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• v.5 no.4
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• pp.211-220
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• 2005

The purpose of this study was to examine the job performance of dental coordinators and their perception of their job to lay the groundwork for utilizing dental personnels more efficiently. The subjects in this study were dental coordinators who worked at selected dental hospitals and clinics in Seoul, Gyeonggi province and Incheon. A survey was conducted to gather data from May 1 to August 8, 2005 and answer sheets from 108 respondents were analyzed. The findings of the study were as follows: 1. As for the length of service, 43.5 percent of the dental coordinators investigated had worked at dental institutes for five years or more, which was followed by less than two years(19.5%) and three years to less than five years(19.4%). Concerning the length of service as dental coordinators, 39.8 percent had served for less than two years, and 19.4 percent had worked for two years to less than three years and for five years or more respectively. Regarding the name of position, 38 percent were called team leaders, and 30.6 percent were called coordinators. As to duties, the largest group of them that stood at 30.6 percent were in charge of receiving, and in regard to department, the largest group, 57.4 percent, belonged to the treatment backup department. 2. Concerning education, the greatest number of them, 45.4 percent, had received education at private institutes, and 73.1 percent found it necessary for dental coordinators to take an authorized qualification test. 43.5 percent, the largest group, looked upon the central government as the best organization to authorize their qualifications and 70.8 percent believed that what they learned enabled them to perform their job successfully. As to the necessity of follow-up education as a means to improve job performance, 96.3 percent consented to it. As for the reason, 63.9 percent considered that necessary to enhance their own ability and 22.2 percent were in want of systematic education. Regarding educational expenses, 29.6 percent were subsidized by the dental institutes where they had worked and 25.9 percent had totally been responsible for that. Regarding a required course, medical service and marketing was most widely pointed out(66.7%), followed by theory and practice(65.7%) and introduction to dentistry(57.4%). As to what sort of education they wanted to receive more, dental service and marketing was selected the most, followed by practical health insurance(35.2%). 3. In regard to what type of job they performed as dental coordinators, 88.9 percent were in charge of appointment in the field of customer service, and 87.9 percent paid attention to having good manners as service providers in the area of self-management. In the field of hospital affairs, 81.3 percent were in charge of receiving. 4. As to their awareness of dental coordinator job, the largest group took pride in the job they performed ($3.99{\pm}0.76$), and the second largest group believed that dental coordinators made a great contribution to hospital management ($3.92{\pm}0.70$). The third largest group gave a great weight to their own job ($3.91{\pm}0.84$) in light of overall dental duties and the fourth largest group found themselves to get along with other employees regardless of position ($3.86{\pm}0.74$). The fifth largest group believed their job was of great use for promoting the oral health of patients ($3.76{\pm}0.75$), and the sixth largest group thought the future of dental coordinators was promising($3.74{\pm}0.86$). 5. In regard to their perception by age group, those who were older had a better opinion on every item of their job in general. Their age made a statistically significant difference to their view of the weight of dental coordinator job(P < 0.001) in light of overall dental duties, of being approved and trusted by managers(P < 0.01), of social awareness of dental coordinator, and of being understood and approved by other employees and dentists. Their pride in current job and their satisfaction with the name of their position were statistically significantly different according to their age as well. Besides, their age made a statistically significant difference to their opinion about whether or not there was an age limit to their occupation and about their contribution to hospital management (P < 0.05). 6. As for their perception by type of job, the dental hygienists were generally most satisfied with their job, followed by nursing aids and others. There was a statistically significant gap among their opinions about whether to make a job-related decision on their own(P < 0.001). the weight of their job in terms of overall dental duties, whether their job improved their ability, whether their job made a great contribution to enhancing the oral health of patients, whether their job was understood and approved by other employees(P < 0.01), social awareness of their job, whether they conflicted with other employees during job performance, and whether dental hospitals or clinics offered a self-development opportunity for them to take their ability to another level(P < 0.05). And their satisfaction with current pay was statistically significantly different as well.