• The Journal of the Korean bone and joint tumor society
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• v.6 no.1
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• pp.22-29
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• 2000

Purpose : The purpose of the current study was to report the results of curettage and en bloc excision as well as to introduce how to excise the nidus percutaneously with Halo-mill. Material and Methods : Twenty patients(14 men and 6 women) were evaluated, who had operative treatments after diagnosed as osteoid osteoma from March 1990 to January 1998. These patients ranged in age from 7 to 42 years(average: 20.8 years). Locations were 9 femurs, 6 tibias, 2 vertebras, 1 ulna, 1 maxilla and 1 skull. Nine femoral lesions included 5 proximal metaphysis, 2 neck and 2 diaphysis, while 5 tibial lesions included 3 diaphysis, 1 proximal metaphysis and 1 distal metaphysis. We used simple radiography, bone scan, CT and MRI for the accurate diagnosis and localization. As for surgical treatments, while excision and curettage had to need open-exposure of lesion, the percutaneous excision of nidus did not need openexposure : guided Halo-mill into K-wire inserted to nidus under image intensifier. Results : Simple radiography showed that 10 cases had typical nidus and others had only cortical sclerosis. Bone scan was performed at 14 cases and all had hot uptake except one case. We used CT in 10 cases and MRI in 4 cases as diagnostic methods, of which 1 case didn't reveal nidus at CT. Surgical treatment consisted of 6 curettages, 11 excisions, 2 percutaneous excisions with halo-mill and 1 total elbow arthroplasty. We used 7mm sized Halo-mill. During the follow-up period, all patient relieved symptoms and there were no recurrences. All had histologically typical findings except one which had hyperostosis without nidus. Conclusion : Complete removal of the nidus is the most important factor in the treatment. We could excise the nidus percutaneously in 2 cases with the minimal injury to surrounding soft tissues. If we could evaluate the precise location, size of nidus and percutaneous acccesibility, the percutaneous excision of nidus with Halo-mill could be an alternative method as a treatment of osteoid osteoma.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.43-47
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• 2009

Purpose: The menstrual cycle of normal premenopausal patients was divide into menstrual flow phase, proliferative phase, ovulatory phase, secretory phase. The aim of this study was to ovarian and endometrial $^{18}F$-FDG uptake during the menstrual cycle in normal premenopausal patients. Materials and Methods: We identified 200 incidental $^{18}F$-FDG uptake in the ovary. The patient fasted at least 6 hours before receiving an intravenous injection of 370-592 MBq (10-16mCi) of $^{18}F$-FDG. Scanning from the base of the skull though the mid thigh was performed using the Discovery Ste PET/CT system (GE Healthcare, Milwaukee, WI, USA). Ovarian and endometrial $^{18}F$-FDG uptake (expressed as standardized uptake value) was measured on PET/CT image. Results: Two peaks of increased endometrial $^{18}F$-FDG uptake were identified during the menstrual cycle. The $SUV_{avg}$ and $SUV_{max}$ was $2.89{\pm}1.04$ and $3.17{\pm}1.59$ in menstruating patients, $2.4{\pm}0.88$ and $2.98{\pm}1.14$ in proliferative phase patients, $3.59{\pm}1.76$ and $3.17{\pm}1.67$ in ovulatory phase patients, $2.58{\pm}1.39$ and $3.1{\pm}1.8$ in secretory phase patients. Conclusions: Increased ovarian and endometrial $^{18}F$-FDG uptake could be found the time of menstrual flow and ovulatory phase of menstrual cycle. Increased uptake in endometrial adjacent to a cervical tumor does not necessarily reflect endometrial tumor invasion. Since increased uptake was dependent on the menstrual cycle, it can be avoided by scheduling PET/CT just after menstruation. Non-menstrual-related endometrial uptake may be instrumental in establishing a diagnosis in a premenopaual patient.

• Radiation Oncology Journal
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• v.21 no.1
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• pp.94-99
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• 2003

Purpose : To explore a 3D conformal radiotherapy technique for a posterior fossa boost, and the potential advantages of a prone position for such radiotherapy. Materials and Methods :A CT simulator and 3D conformal radiotherapy Planning system was used for the posterior fossa boost treatment on a 13-year-old medulloblastoma patient. He was placed In the prone position and Immobilized with an aquaplast mask and immobilization mold. CT scans were obtained of the brain from the top of the skull to the lower neck, with IV contrast enhancement. The target volume and normal structures were delineated on each slice, with treatment planning peformed using non-coplanar conformal beams. Results : The CT scans, and treatment In the prone position, were peformed successfully. In the prone position, the definition of the target volume was made easier due to the well enhanced tentorium, In audition, the posterior fossa was located anteriorly, and with the greater choice of beam arrangements, more accurate treatment planning was possible as the primary beams were not obstructed by the treatment table. Conclusion : .A posterior fossa boost, in the prone position, Is feasible in cooperating patients, but further evaluation is needed to define the optimal and most comfortable treatment positions.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.325-335
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• 1998

Purpose : Since the mid cranial fossa is composed of various thickness of bone, the tissue inhomogeneity caused by bone would produce dose attenuation in cobalt-60 gamma knife irradiation. The correction factor for bone attenuation of cobalt-60 which is used for gamma knife source is -3.5$\%$. More importantly, nearly all the radiosurgery treatment planning systems assume a treatment volume of unit density: any perturbation due to tissue inhomogeneity is neglected, This study was performed to confirm the bone attenuation in mid cranial fossa using gamma knife. Materials and Methods : Computed tomography was performed after Leksell stereotactic frame had been liked to the Alderson Rando Phantom (human phantom) skull area. Kodak X-omat V film was inserted into two sites of pituitary adenoma point and acoustic neurinoma point, and irradiated by gamma knife with 14mm and 18mm collimator. An automatic scanning densitometer with a 1mm aperture is used to measure the dose profile along the x and y axis. Results : Isodose curve constriction in mid cranial fossa is observed with various ranges. Pituitary tumor point is greater than acoustic neurinoma point (0.2-3.0 mm vs 0.1-1.3 mm) and generally 14 mm collimator is greater than 18mm collimator (0.4-3.0 mm vs. 0.2-2.2 mm) Even though the isodose constriction is found, constriction of 50$\%$ isodose curve which is used for treatment reference line does not exceed 1 mm. This range is too small to influence the treatment planning and treatment results. Conclusion : Radiosurgery planning system of gamma knife does not show significant error to be corrected without consideration of bone attenuation.