In this study we estimated a geometric correlation among digitally reconstructed radiographic image (DRRI), kV x-ray image (kVXI) from the On-Board Imager (OBI) and electric portal image (EPI). To verify geometric correspondence of DRRI, kVXI and EPI, specially designed phantom with indexed 6 ball bearings (BBs) were employed. After accurate setup of the phantom on a treatment couch using orthogonal EPIs, we acquired set of orthogonal kVXIs and EPIs then compared the absolute positions of the center of the BBs calculated at each phantom plane for kVXI and EPI respectively. We also checked matching result for obliquely incident beam (gantry angle of 315 degrees) after 2D-2D matching provided by OBI application. A reference EPI obtained after initial setup of the phantom was compared with 10 series of EPIs acquired after each 2D-2D matching. Imaginary setup errors were generated from -5 mm to 5 mm at each couch motion direction. Calculated positions of all center positions of the BBs at three different images were agreed with the actual points within a millimeter and each other. Calculated center positions of the BBs from the reference and obtained EPIs after 2D-2D matching agreed within a millimeter. We could tentatively conclude that the OBI system was mechanically quite reliable for image guided radiation therapy (IGRT) purpose.
Radiotherapy, Image-Guided

BACKGROUND: Family physicians in their on primary practice frequently encounters patients with fever, welch is one of the common symptoms. Fever is an important symptom and can occur in mild disease, common cold, influenza, acute pharyngotonsillitis or can originate from a particular severe disease, such as bacterial endocarditis, malignant lymphoma and SLE, which need more aggressive management. Therefore, we studied patients who were admitted with short-term fever or long-term fever to find out their causes of febrile disease and to compare the differences with previous other studies. METHODS: 601 patients with fever above 37.2 degree centigrade or those who were transferred from other hospitals due to long-term fever were enrolled from Jan. 1991 to Jun. 1997. Patients' medical records reviewed and were classified according to disease, sex, age. Standardization of Petersdorf's rule for F.U.O. was used. RESULTS: 601 patients were randomly selected among which 301 were males and 300 females. Males were 147 and females 147 young adult patients as compared to 154 males and 153 females were elderly patients. According to disease category, the number of infections, connective tissue diseases, neoplastic diseases and other diseases were 442(73.5%), 14(2.3%), 87(14.5%) and 21(3.5%), respectively. The number of diseases of undetermined case was 37(6.2%). The most frequent disease was pneumonia with 103(31.1%). UTI and tuberculosis were the 2nd and 3rd most common diseases. The total number of F.U.O. patients was 82(13.6%). According to the disease categories there were 29(35.4%) in infections, 2(2.4%) in connective tissue diseases, 12(14.6%) in neoplasms, 2(2.4%) in others and 37(45.2%) in unknown origin. The most common disease was tuberculosis. Infection and tuberculosis were common disease category and disease in the classification of sex and age of F.U.O.. CONCLUSIONS: In the clinical study of febrile patients admitted from Jan. 1991 to Jun.1997 through medical record review, the disease category in the order of frequency was infection, neoplasm, collective tissue disease and the distribution of F.U.0. was same result. In comparison with other study, the order of connective tissue disease and neoplasm was different in other hospital study but same result was taken In comparison with Petersdorf's study.
Aged ; Classification ; Common Cold ; Communicable Diseases ; Connective Tissue Diseases ; Endocarditis, Bacterial ; Female ; Fever of Unknown Origin* ; Fever* ; Humans ; Influenza, Human ; Lymphoma ; Male ; Medical Records ; Physicians, Family ; Pneumonia ; Tuberculosis ; Young Adult

PURPOSE: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on-board imager (OBI). MATERIALS AND METHODS: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed COMOBI with the reference COMCT. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. RESULTS: In the phantom study, the calculated COMCT and COMOBI agreed with COMactual within a millimeter. The algorithm also could localize each seed marker correctly and calculated COMCT and COMOBI for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of 0.1+/-2.7~1.8+/-6.6 mm in the AP direction, 0.8+/-1.6~2.0+/-2.7 mm in the SI direction and -0.9+/-1.5~2.8+/-3.0 mm in the lateral direction, even though the setup error was quite patient dependent. CONCLUSION: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.
Axis, Cervical Vertebra ; Humans ; Prostate ; Prostatic Neoplasms ; Radiotherapy

Paramyotonia congenita (PMC), an autosomal dominant non-progressive muscle disorder, is characterised by cold-induced stiffness followed by muscle weakness. The weakness is considered to be caused by a dysfunction of the sodium channel in muscle fiber. We report a 37-year-old male patient with PMC, complaining of episodic myotonia and motor weakness on cold exposure. In this patient, we performed clinical and neurological examination, electrophysiologic examination and muscle biopsy. On electrophysiologic study, needle EMG showed spontaneous myotonic discharges at room temperature but disappeared after cooling. Amplitude of compound action potential in abductor pollicis brevis muscle decreased significantly after cooling the tested extremity. Muscle biopsy showed a minimal variation of muscle fiber diameters, internal nuclei, chained nuclei, occasional atrophic fibers in vastus lateralis muscle. His mother, his son, three of six siblings, and five of eleven nephewes are affected with same symptomes.
Action Potentials ; Adult ; Biopsy ; Extremities ; Humans ; Male ; Mothers ; Muscle Weakness ; Muscular Diseases ; Myotonia ; Myotonic Disorders* ; Needles ; Neurologic Examination ; Quadriceps Muscle ; Siblings ; Sodium Channels

Twenty-our cases of pituitary adenoma, 13 males and 11 females with the age ranging from 11 to 65 years, received radiation therapy(RT) on the pituitary area with 6MV linear accelerator during past 25 months at the Division of Radiation Therapy, Kangnam St. Mary's Hospital, Catholic Medical College. Of 24 case of RT, 20 were postoperative and 4 primary. To evaluate the effect of RT, we analyzed the alteration of the endocrinologic tests, neurologic abnormalities, major clinical symptoms, endocrinologic changes and improvement in visual problems after RT. The results were as follows ; 1. Major clinical symptoms were headache, visual defects, diabetes insipidus, hypogonadisms and general weakness in decreasing order of frequency. 2. All but the one with Nelson's syndrome showed abnormal neuroradiologic changes in the sella turcica with an invasive tumor mass around supra and para-ellar area. 3. Endocrinological classifications of the patient were 11 prolactinoma, 4 growth hormonesecreting tumors, 3 ACTH-ecreting tumors consisting of one Cushing's disease and two Nelson's syndrome, and 6 nonfunctioning tumors. 4. Eleven of 14 patients, visual problems were improved after treatment but remaining 3 were unchanged. 5. Seven of 11 prolactinomas returned to normal hormonal level after postoperative and primary RT and 3 patients are being treated with bromocriptine (BMCP) but on lost case. 6. Two of 4 growth hormone-ecreting tumor returned to normal level after RT but the remaining 2 are being treated with BMCP, as well.
Bromocriptine ; Classification ; Diabetes Insipidus ; Female ; Growth Hormone* ; Headache ; Humans ; Male ; Particle Accelerators ; Pituitary Neoplasms* ; Plasma* ; Prolactinoma ; Sella Turcica

Less execution of the electron arc treatment could in large part be attributed to the lack of an adequate planning system. Unlike most linear accelerators providing the electron arc mode, no commercial planning systems for the electron arc plan are available at this time. In this work, with the expectation that an easily accessible planning system could promote electron arc therapy, a commercial planning system was commissioned and evaluated for the electron arc plan. For the electron arc plan with use of a Varian 21-EX, Pinnacle3 (ver. 7.4f), with an electron pencil beam algorithm, was commissioned in which the arc consisted of multiple static fields with a fixed beam opening. Film dosimetry and point measurements were executed for the evaluation of the computation. Beam modeling was not satisfactory with the calculation of lateral profiles. Contrary to good agreement within 1% of the calculated and measured depth profiles, the calculated lateral profiles showed underestimation compared with measurements, such that the distance-to-agreement (DTA) was 5.1 mm at a 50% dose level for 6 MeV and 6.7 mm for 12 MeV with similar results for the measured depths. Point and film measurements for the humanoid phantom revealed that the delivered dose was more than the calculation by approximately 10%. The electron arc plan, based on the pencil beam algorithm, provides qualitative information for the dose distribution. Dose verification before the treatment should be mandatory.
Electrons ; Film Dosimetry ; Particle Accelerators

Most brachytherapy treatment planning systems employ a dosimetry formalism based on the AAPM TG-43 report which does not appropriately consider tissue heterogeneity. In this study we aimed to set up a simple Monte Carlo-based intracavitary high-dose-rate brachytherapy (IC-HDRB) plan verification platform, focusing particularly on the robustness of the direct Monte Carlo dose calculation using material and density information derived from CT images. CT images of slab phantoms and a uterine cervical cancer patient were used for brachytherapy plans based on the Plato (Nucletron, Netherlands) brachytherapy planning system. Monte Carlo simulations were implemented using the parameters from the Plato system and compared with the EBT film dosimetry and conventional dose computations. EGSnrc based DOSXYZnrc code was used for Monte Carlo simulations. Each (192)Ir source of the afterloader was approximately modeled as a parallel-piped shape inside the converted CT data set whose voxel size was 2x2x2 mm3. Bracytherapy dose calculations based on the TG-43 showed good agreement with the Monte Carlo results in a homogeneous media whose density was close to water, but there were significant errors in high-density materials. For a patient case, A and B point dose differences were less than 3%, while the mean dose discrepancy was as much as 5%. Conventional dose computation methods might underdose the targets by not accounting for the effects of high-density materials. The proposed platform was shown to be feasible and to have good dose calculation accuracy. One should be careful when confirming the plan using a conventional brachytherapy dose computation method, and moreover, an independent dose verification system as developed in this study might be helpful.
Accounting ; Brachytherapy ; Film Dosimetry ; Humans ; Monte Carlo Method ; Organoplatinum Compounds ; Population Characteristics ; Uterine Cervical Neoplasms ; Water

PURPOSE: This study was performed to assess frequency, timings of occurrence, and predictors of radiologic lung damage (RLD) after forward-planned intensity-modulated radiotherapy (FIMRT) for whole breast irradiation. METHODS: We retrospectively reviewed medical records of 157 breast cancer patients and each of their serial chest computed tomography (CT) taken 4, 10, 16, and 22 months after completion of breast radiotherapy (RT). FIMRT was administered to whole breast only (n=152), or whole breast and supraclavicular regions (n=5). Dosimetric parameters, such as mean lung dose and lung volume receiving more than 10 to 50 Gy (V10-V50), and clinical parameters were analyzed in relation to radiologic lung damage. RESULTS: In total, 104 patients (66.2%) developed RLD after whole breast FIMRT. Among the cases of RLD, 84.7% were detected at 4 months, and 15.3% at 10 months after completion of RT. More patients of 47 or younger were found to have RLD at 10 months after RT than patients older than the age (11.7% vs. 2.9%, p=0.01). In univariate and multivariate analyses, age >47 and V40 >7.2% were significant predictors for higher risk of RLD. CONCLUSION: RLD were not infrequently detected in follow-up CT after whole breast FIMRT. More detected cases of RLD among younger patients are believed to have developed at later points after RT than those of older patients. Age and V40 were significant predictors for RLD after whole breast intensity-modulated radiotherapy.
Breast Neoplasms ; Breast* ; Follow-Up Studies ; Humans ; Lung Injury* ; Lung* ; Medical Records ; Multivariate Analysis ; Radiotherapy ; Radiotherapy, Intensity-Modulated* ; Retrospective Studies ; Thorax

We aimed to setup an adaptive radiation therapy platform using cone-beam CT (CBCT) and multileaf collimator (MLC) log data and also intended to analyze a trend of dose calculation errors during the procedure based on a phantom study. We took CT and CBCT images of Catphan-600 (The Phantom Laboratory, USA) phantom, and made a simple step-and-shoot intensity-modulated radiation therapy (IMRT) plan based on the CT. Original plan doses were recalculated based on the CT (CTplan) and the CBCT (CBCTplan). Delivered monitor unit weights and leaves-positions during beam delivery for each MLC segment were extracted from the MLC log data then we reconstructed delivered doses based on the CT (CTrecon) and CBCT (CBCTrecon) respectively using the extracted information. Dose calculation errors were evaluated by two-dimensional dose discrepancies (CTplan was the benchmark), gamma index and dose-volume histograms (DVHs). From the dose differences and DVHs, it was estimated that the delivered dose was slightly greater than the planned dose; however, it was insignificant. Gamma index result showed that dose calculation error on CBCT using planned or reconstructed data were relatively greater than CT based calculation. In addition, there were significant discrepancies on the edge of each beam while those were less than errors due to inconsistency of CT and CBCT. CBCTrecon showed coupled effects of above two kinds of errors; however, total error was decreased even though overall uncertainty for the evaluation of delivered dose on the CBCT was increased. Therefore, it is necessary to evaluate dose calculation errors separately as a setup error, dose calculation error due to CBCT image quality and reconstructed dose error which is actually what we want to know.
Cone-Beam Computed Tomography ; Organothiophosphorus Compounds ; Uncertainty ; Weights and Measures

Radiation treatment techniques using photon beam such as three-dimensional conformal radiation therapy (3D-CRT) as well as intensity modulated radiotherapy treatment (IMRT) demand accurate dose calculation in order to increase target coverage and spare healthy tissue. Both jaw collimator and multi-leaf collimators (MLCs) for photon beams have been used to achieve such goals. In the Pinnacle3 treatment planning system (TPS), which we are using in our clinics, a set of model parameters like jaw collimator transmission factor (JTF) and MLC transmission factor (MLCTF) are determined from the measured data because it is using a model-based photon dose algorithm. However, model parameters obtained by this auto-modeling process can be different from those by direct measurement, which can have a dosimetric effect on the dose distribution. In this paper we estimated JTF and MLCTF obtained by the auto-modeling process in the Pinnacle3 TPS. At first, we obtained JTF and MLCTF by direct measurement, which were the ratio of the output at the reference depth under the closed jaw collimator (MLCs for MLCTF) to that at the same depth with the field size 10x10 cm2 in the water phantom. And then JTF and MLCTF were also obtained by auto-modeling process. And we evaluated the dose difference through phantom and patient study in the 3D-CRT plan. For direct measurement, JTF was 0.001966 for 6 MV and 0.002971 for 10 MV, and MLCTF was 0.01657 for 6 MV and 0.01925 for 10 MV. On the other hand, for auto-modeling process, JTF was 0.001983 for 6 MV and 0.010431 for 10 MV, and MLCTF was 0.00188 for 6 MV and 0.00453 for 10 MV. JTF and MLCTF by direct measurement were very different from those by auto-modeling process and even more reasonable considering each beam quality of 6 MV and 10 MV. These different parameters affect the dose in the low-dose region. Since the wrong estimation of JTF and MLCTF can lead some dosimetric error, comparison of direct measurement and auto-modeling of JTF and MLCTF would be helpful during the beam commissioning.
Hand ; Humans ; Jaw ; Water