The energy spectra and dose calculations were performed for secondary neutrons from a 24 MV LINAC using MCNPX code (V2, 4, 0). The energy spectra for neutrons and photons emitted from the LINAC head, and absorbed dose to water were calculated in water phantom. The absorbed doses calculated with Monte Carlo were 0.66~0.35 mGy/photon Gy at the surface to d=5 cm, and calculated with interaction data was 0.52 mGy/photon Gy at the depth of electron equilibrium in water. We have shown that this work can be applied to dose estimation of neutrons from high energy LINAC through the comparison of our results with other results.
Head ; Neutrons* ; Photons ; Water

PURPOSE: To evaluate injury patterns of facet joints and associated soft tissue injuries in patients withacute traumatic cervical facet joint injuries. MATERIALS AND METHODS: From among patients with cervical spinetrauma, 27 with facet joint injuries, as seen on CT and MRI, were chosen for this study. CT scans were analyzedwith regard to the location of facet joint injury, the presence or absence of facet dislocation or fracture, andother associated fractures. MR images were analyzed with regard to ligament injury, intervertebral disc injury,intervertebral disc herniation, and spinal cord injury. RESULTS: The most common location of facet joint injurywas C6-7 level(n=10), followed by C5-6(n=8). Among these 27 patients with facet joint injuries, 12(44%) hadbilateral injuries and 15(56%) unilateral injuries. Facet fractures were present in 17 cases(63%) and the fractureof inferior facet was more frequent than superi-or. Patterns of fracture were vertical, transverse, or comminuted,but vertical fracture was the most common. Various degrees of dislocation were observed in patients with facetfractures. Fractures other than facet includ-ed pillar(n=11), lamina(n=6), transverse process(n=14), body(n=13),and spinous process(n=3). On MR im-ages, anterior longitudinal ligament injury was found in 8 patients(30%),posterior longitudinal ligament injury in 4(15%), and interspinous ligament injury in 20(74%). Twelvepatients(44%) had spinal cord injuries includ-ing edema(n=8) and hemorrhage(n=4). Among patients with discabnormalities, 11(41%) had intervertebral disc injuries, and traumatic disc herniations were found in nine. CONCLUSION: Traumatic cervical facet joint injuries were manifested as various patterns and frequentlyassoci-ated with other fractures or soft tissue injuries. Analysis of CT and MR findings of these injury patternshelped formulate a therapeutic plan and determine of prognosis.
Dislocations ; Humans ; Intervertebral Disc ; Ligaments ; Longitudinal Ligaments ; Magnetic Resonance Imaging* ; Prognosis ; Soft Tissue Injuries ; Spinal Cord Injuries ; Spine* ; Tomography, X-Ray Computed ; Zygapophyseal Joint*

PURPOSE: In order to obtain basic data for treatment plan in radiosurgery, we measured small fields of 6 MV X-rays and compared the measured data with our Monte Carlo simulations for the small fields. MATERIALS AND METHODS: The small fields of 1.0, 2.0 and 3.0 cm in diameter were used in this study. Percentage depth dose (PDD) and beam profiles of those fields were measured and calculated. A small semiconductor detector, water phantoms, and a remote control system were used for the measurement. Monte Carlo simulations were performed using the EGS4 code with the input data prepared for the energy distribution of 6 MV X-rays, beam divergence, circular fields and the geometry of the water phantoms. RESULTS: In the case of PDD values, the calculated values were lower than the measured values for all fields and depths, with the differences being 0.3 to 5.7% at the depths of 2.0 to 20.0 cm and 0.0 to 8.9% at the surface regions. As a result of the analysis of beam profiles for all field sizes at a depth of 10cm in water phantom, the measured 90% dose widths were in good agreement with the calculated values, however, the calculated penumbra radii were 0.1 cm shorter than measured values. CONCLUSION: The measured PDDs and beam profiles agreement with the Monte Carlo calculations approximately. However, it is different when it comes to calculations in the area of phantom surface and penumbra because the Monte Carlo calculations were performed under the simplified geometries. Therefore, we have to study how to include the actual geometries and more precise data for the field area in Monte Carlo calculations. The Monte Carlo calculations will be used as a useful tool for the very complicated conditions in measurement and verification.
Radiosurgery ; Semiconductors ; Water

PURPOSE: To evaluate the usefulness of the coaxial technique in US-guided breast core biopsy. Materials andMethods : Using the coaxial technique, US-guided breast core biopsy was performed in 49 breast lesions (40patients). Under US-guidance the 17-gauge, 13 cm long introducer needle was positioned proximal to the lesion.Once the needle was in place, the central trocar was removed and was replaced with the core biopsy needle. We usedan 18-gauge, 16-cm-long core biopsy needle with a 17 mm specimen notch. Four to eight tissue specimens wereobtained from each lesion, and the quality and quantity of specimens, procedure time, and complications and theirrate were evaluated. RESULTS: For 48 of 49 lesions, specimens were adequate for histopathologic diagnosis, andthe findings were as follows : six cases of invasive ductal carcinoma, one of ductal carcinoma in situ, 29 offibrocystic disease, eight of fibroadenoma, two of chronic inflammation, and two of sclerosing lesion. In 12lesions agreement between the pathologic results of needle core biopsy and surgical results was 100%. Theprocedure time was about 15 minutes and no significant complications were noted. CONCLUSION: In breast corebiopsy, the coaxial technique is simple and time-saving, and compared with stan-dard breast core biopsy, may alsobe less traumatic and decrease the potential risk of seeding the biopsy tract with malignant cells.
Biopsy* ; Breast* ; Carcinoma, Ductal ; Carcinoma, Intraductal, Noninfiltrating ; Diagnosis ; Fibroadenoma ; Inflammation ; Needles ; Surgical Instruments

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare neoplasm that is frequently located in the distal extremities. Emerging evidence suggests that MIFS can also affect the proximal limbs, trunk, and scalp, and aggressive clinical courses have been noted. We report a case of MIFS that occurred suddenly in the patient’s forearm and grew rapidly within 2 weeks. A level of Ki-67 was observed in the patient’s lesion, which constitutes a considerable finding compared with most MIFS cases. The patient underwent surgical tumor removal, and no evidence of recurrence was noted. We highlight this case in view of its sudden occurrence and rapid local progression, which contradicts the usual features of this disease, suggesting that this clinical course might be attributable to the high Ki-67 value.

Cervical pregnancy is a rarely life-threatening form of ectopic pregnancy in which the implantation of the developing conceptus in the cervical canal. The cervix is composed predominantly of the fibrous tissue. Therefore cervical pregnancy can be massive hemorrhagic occurrence from the eroded blood vessels within the cervical tissue. In the past, as a result of life-threatening hemorrhage, the diagnosis of a cervical ectopic pregnancy frequently led to hysterectomy. Currently, several conservative treatments are possible with the hope of preserving future reproductive potential, including preoperative uterine artery embolization before dilatation and evacuation. We report a case of cervical pregnancy which was treated sucessfully with preoperative selective uterine artery embolization before dilatation and currettage.
Blood Vessels ; Cervix Uteri ; Cytochrome P-450 CYP1A1 ; Diagnosis ; Dilatation ; Female ; Hemorrhage ; Hope ; Hysterectomy ; Pregnancy* ; Pregnancy, Ectopic ; Uterine Artery Embolization* ; Uterine Artery*

The compatibility with GammaMed-12i brachytherapy machine for an Ir-192 encapsulated source (IRRS20, KAERI, Korea) manufactured by Korea atomic energy research institute (KAERI) has been investigated. As a mechanical testing of compatibility, precise measurement of step movement with channels, measurement of curvature of radius for wire, and emergency return testing were performed. Periodic measurements of air kerma strength for 45 days were carried out to evaluate decay characteristics of Ir-192 radioisotope and comparison of dose distributions in phantom between KAERI and old sources previously used were performed by film dosimetry. KAERI source has a good compatibility with GammaMed12i machine as a result of mechanical testing. There are in good agreement with calculated values in activity characteristics and there were small differences in dose distributions around the source in comparison between KAERI and old source.
Academies and Institutes ; Brachytherapy ; Emergencies ; Film Dosimetry ; Korea ; Nuclear Energy ; Radius

The quality factors for cylindrical ionization chambers for kV X-rays were determined by Monte Carlo calculation and measurement. In this study, the X-rays of 60~300 kV beam (ISO-4037) installed in KFDA and specified in energy spectra and beam qualities, and the chambers of PTW N23333 and N30001 were investigated. In calculations, the k(u) and k(Q,Q(0)) in IAEA dosimetry protocols were determined from the air kerma and the cavity dose obtained by theoretical and Monte Carlo calculations. It is shown that the N30001 chamber has a flat response of +/-1.7% in 110~300 kV region, while the response range of two chambers were shown to +/-3~4% in 80~250 kV region. From this work we have discussed dosimetry protocol for the kV X-rays and we have found that the estimation of energy dependency is more important to apply dosimetry protocol for kV X-rays.

No abstract available.
Myofibroblasts* ; Thyroid Gland*

In this study, we have estimated error of calculation results for 6-type RTP systems and investigated a toleration for error of the RTPs referenced from the evaluation items of AAPM Report-62. For this study, we have introduced the concept of 'normal dose rate(NDR)' and compared the results of experiment and calculation from RTPs at the same reference level. The results from all RTPs were satisfied at various field shapes and heterogeneous phantom materials except the surface irregularity.