It is known that fixed source to skin distance (SSD) cannot be used when the treatment field is sloped or larger than the size of second collimator in electron beam irradiation and inverse square law using effective ssd should be adopted. Effective SSDs were measured in different field sizes in each 6, 9, 12, 15 and 18 MeV electron energy by suing NELAC 1018D linear accelerator of Kosin Medical Center. We found important parmeters of effective SSD. 1. Minimum effective SSD was 58.8 cm in small field size of 6x6 cm and maximum effective SSD was 94.9 cm in large field size of 25x25 cm, with 6 MeV energy. It's difference was 36.1 cm. The dose rate at measuring point was quite different even with a small difference of SSD in small field (6x6 cm) and low energy (6 MeV). 2. Effective SSD increased with field size in same electron energy. 3. Effective SSDs gradually increased with the electron energies and reached maximum at 12 or 15 MeV electron energy and decreased again at 18 MeV electron energy in each identical field size. And so the effective SSD should be measured in each energy and field size for practical radiotherapy.
Jurisprudence ; Particle Accelerators ; Radiotherapy ; Silver Sulfadiazine* ; Skin

BACKGROUND: Onychomycosis, especially toenail onychomycosis has become one of the common fungal infection and has historically been regarded as a cosmetic rather than medical problem by many patients, even by physicians. Recently, however, there are several reports that this is a refractory disease which may cause a deleterious effect on patients' quality of life (QOL). OBJECTIVE: The purpose of this study was to investigate the impact of toenail onychomycosis on QOL in Korea and to assess the changes of QOL after treatment. METHODS: Total 1004 patients with toenail onychomycosis which was confirmed by clinical findings and KOH preparation were enrolled at 47 dermatologic centers in Korea, and interviewed with standardized QOL questionnaire before and after systemic antifungal treatment. Responses to the questionnaire were scored by f-point scale (0~4) and averaged, and were analyzed for 5 dimensions of emotional impact, social impact, symptom and functional impact, patients' views concerning treatment, and relationship with doctor. RESULTS: 1. Before and after treatment, the most serious impact was emotional dimension showing 1.90 and 1.30 in average score (AS), and social (AS: 1.14 and 0.83) and symptom and functional impact (AS: 1.05 and 0.92) was also affected. 2. In female rather than male, statistically more significant impact on patients' QOL was observed in all dimensions. 3. After treatment, 3 of 5 dimensions were improved significantly - emotional dimension (AS: from 1.90 to 1.30), social dimension (AS: from 1.14 to 0.83), patients' view concerning treatment(AS: from 1.34 to 1.02) 4. The degree of patients' satisfaction at the therapeutic effect was very high - 62.4% (immediately after. treatment) and 65.8% (9 months after initiation of treatment) of patients answered excellent or good. CONCLUSION: This study confirms that toenail onychomycosis has significant Impact on the overall QOL of patients. Also the effect of antifungal therapy on patients' QOL were satisfactory. Therefore, both doctor and patient should pay more attention to the treatment of onychomycosis.
Female ; Humans ; Korea* ; Male ; Nails* ; Onychomycosis* ; Quality of Life* ; Social Change ; Surveys and Questionnaires