The patterns of the conventional radiation treatment fields and their shielding blocks are analysed to determine the optimal dimension of the MultiLeaf Collimator (MLC) which is considered as an essential tool for conformal therapy. Total 1169 radiation fields from 303 patients (203 from Asan Medical center, 50 from Baek Hosp and 50 from Hanyang Univ. Hosp.) were analysed for this study. Weighted case selection treatment site (from The Korean Society of Therapeutic Radiology 1003). Ninety one percent of total fields have shielding blocks. Y axis is defined as leaf movement direction and it is assumed that MLC is installed on the cranial-caudal direction. The length of X axis were distributed from 4cm to 40cm (less than 21cm for 95% of cases), and Y axis from 5cm to 38cm (less than 22cm for 95% of cases). The shielding blocks extended to less than 6cm from center of the filed for 95% of the cases. Start length for ninety five percent of block is less than 10cm for X axis and 11cm for Y axis. Seventy six percent of shielding blocks could be placed by either X or Y axis direction, 7.9% only by Y axis, 5.1% only by X axis and it is reasonable to install MLC for Y direction. Ninety five percent of patients can be treated with coplanar rotation therapy without changing the collimator angle. Eleven percent of cases of cases were impossible to replace with MLC. Futher study of shielding should be larger than 21cm X 22cm. The MLC should be designed as a pair of 21 leaves with 1cm wide for an acceptable resolution and 17cm long to enable the leaf to overtravel at least 6cm from the treatment field center.
Axis, Cervical Vertebra ; Chungcheongnam-do ; Humans ; Radiation Oncology

Since Jan. 1992, authors have conducted a pilot study to treat malignant glioma with multiple daily fractionated (MDF) radiation therapy and this paper presents the outcome compared MDF to conventional fractionated (CF) radiation therapy. Between Sep. 1989 and Jan. 1993, forty-three patients with high grade glioma of brain except brain stem glioma were treated: nineteen patients were treated with CF radiation therapy and 24 patients were treated with MDF radiation therapy. In CF radiation therapy, total dose was 6300cHy/35fx in 7 weeks, which 5040cGy was delivered to the initial target volume and 1260cGy to reduced target volume. And in MDF radiation therapy, total dose was 6400cGy/40fx in 4 weeks, which 3200cGy was delivered to the initial target volume as 160cGy 2 times daily 6hr apart. All patients had histologically confirmed anaplastic astrocytoma (AA) of glioblastoma multiforme(GBM) with stereotactic biopsy or craniotomy for subtotal or gross tumor resection. The rage of follow-up was 7 months to 4 years with a median follow-up of 9 months. The Median survival from surgery was 9 months for all patients. The median survival was 9 months and 10 months for MDF group and CF group and 10 months and 9. 5 months for glioblastoma multiforme and anaplastic astrocytoma, respectively. In 36 patients with follow-up CT scan or MRI scan, disease status was evaluated according to treatment group. Four patients (GBM:3, AA:1) of 21 patients in MDF group, were alive with no evidence of disease, while none of patient was alive with no evidence of disease in CF group. The progression of disease had occurred in 20 patients, 11 patients and 9 patients in MDF group and CF group, espectively. All of these patients showed in-field progression of disease. Four of 11 patients (27%) in MDF group showed the new lesion outside of the treatment field, while 5 of 9 patients(56%) in CF group. In our study the prognosis was not influenced by age, KPS, grade, extent of surgery and different fractional scheduled radiation therapy. Authors concluded that MDF regimen was well tolerated and shortened the treatment period from 7 weeks to 4 weeks without compromising results. We believe that further follow-up is needed to assess the role of MDF.
Astrocytoma ; Biopsy ; Brain ; Brain Stem ; Craniotomy ; Follow-Up Studies ; Glioblastoma ; Glioma* ; Humans ; Magnetic Resonance Imaging ; Pilot Projects ; Prognosis ; Rage ; Tomography, X-Ray Computed

Collagen and its products, used in some medical field are relatively safe but may induce hypersensitivity reaction. However, pulmonary embolism is a rare but serious complication after injection of them. A-48-year old woman was admitted because of cough, hemoptysis and dyspnea. Nine days ago, she had received breast augmentation with injectable collagen by unlicensed person. Four days later, she experienced cough, hemoptysis and dyspnea. On admission right side pleural effusion and peripheral distributed diffuse consolidations in both lungs were noted on chest radiograph. A computed tomographic (CT) scan of the chest showed non-segmental distribution of bilateral ground-glass opacity and interlobular septal thickening with multifocal consolidation in both lungs. Sputum and urine cytologic examination revealed foamy histiocytes containing lipid vaculoes. Conservative management was done under the impression of pulmonary embolism after collagen injection. She was dischared with full recovery. Here, we report a case of pulmonary embolism occurred after infection of collagen first in Korea.
Breast ; Collagen* ; Cough ; Dyspnea ; Female ; Hemoptysis ; Histiocytes ; Humans ; Hypersensitivity ; Korea ; Lung ; Pleural Effusion ; Pulmonary Embolism* ; Radiography, Thoracic ; Sputum ; Thorax

A system to non-invasively fix and monitor eye by a head mounted display (HMD) with a CCD camera for stereotactic radiotherapy (SRS) of uveal melanoma has been developed and implemented clinically. The eye fixing and monitoring system consists of a HMD showing patient a screen for fixing eyeball, a CCD camera monitoring patient' s eyeball, and an immobilization mask. At first, patient' s head was immobilized with a mask. Then, patient was instructed to wear HMD, to which CCD camera was attached, on the mask and see the given reference point on its screen. While patient stared at the given point in order to fix eyeball, the camera monitored its motion. Four volunteers and one patient of uveal melanoma for SRS came into this study. For the volunteers, setup errors and the motion of eyeball were analyzed. For the patient, CT scans were performed, with patient' s wearing HMD and fixing the eye to the given point. To treat patient under the same condition, daily CT scans were also performed before every treatment and the motion of lens was compared to the planning CT. Setup errors for four volunteers were within 1 mm and the motion of eyeball was fixed within the clinically acceptable ranges. For the patient with uveal melanoma, the motion of lens was fixed within 2 mm from daily CT scans. An eye fixing and monitoring system allowed immobilizing patient as well as monitoring eyeball and was successfully implemented in the treatment of uveal melanoma for SRS.
Head* ; Humans ; Immobilization ; Masks ; Melanoma ; Radiotherapy ; Tomography, X-Ray Computed ; Volunteers

Legionella species are abundant in the built environment and are increasingly recognized as a cause of Legionnaires' disease (LD). As the number of cases of Legionnaires' disease acquired by local communities in the Seoul metropolitan area in Korea has been increased, there was concern that changes in environmental factors could affect disease outbreaks. We described the association between climatic variables and occurrence of legionellosis in Korea and Legionella detection rate in Seoul area. A total of 418 cases of legionellosis were reported between 2014 and 2017. There was a seasonal peak in summer. LD continuously occurred from early spring to winter every year and rapidly increased in summer. In the regression analysis, the primary variables of interest- PM2.5 (µg/m³), NO₂ (ppb), and a number of the date of issue O₃ warning were not significant except for average temperature (R²=0.8075). The Legionella detection rate in Seoul, Korea showed a trend similar to precipitation (P=0.708, ANOVA). A relatively high proportion of Legionella detection rate was shown, especially cooling tower (17.7%) and public bath (19.3%). This finding is in line with current understanding of the ecological profile of this pathogen and supports the assertion that legionellosis occurs through contamination of water sources.
Baths ; Disease Outbreaks ; Epidemiology ; Korea ; Legionella ; Legionellosis ; Legionnaires' Disease ; Regression Analysis ; Seasons ; Seoul ; Water