• The Journal of Korean Society for Radiation Therapy
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• v.19 no.1
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• pp.35-41
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• 2007

Purpose: To evaluate the effectiveness of a simple and practical shielding device to reduce the fetal dose for a pregnant patient undergoing radiation therapy of brain metastasis. Materials and Methods: The dose to the fetus was evaluated by simulating the treatments using the anthropomorphic phantom. The prescription dose at mid-brain is $300cGy{\times}10$ fractions with 6 MV photon with $18{\times}22cm^2$ field size. The additional shielding devices to reduce the fetal dose are a shielding wall, cerrobend plates and lead (Pb) sheets over acrylic bridge. Various points of measurement with off-field distance were detected by using ion-chamber (30, 40, 50, and 60 cm) with and without the shielding devices and TLD (30, 40, 50, 60, and 70 cm) only with the shielding devices. Results: The doses to the fetus without shielding were 3.20, 3.21, 1.44, 0.90 cGy at the distances of 30, 40, 50, and 60 cm from the treatment field edge. With shielding, the doses were reduced to 0.88, 0.60, 0.35, 0.25 cGy, and the ratio of the shielding effect varied from 70% to 80%. TLD results were 1.8, 1.2, 0.8, 1.2, and 0.8 cGy (70 cm). The total dose to the fetus was expected to be under 1 cGy during the entire treatment. Conclusion: The essential point during radiation therapy of pregnant patient would be minimizing the fetal dose. 10 cGy to 20 cGy is the threshold dose for fetal radiation effects. Our newly developed device reduced the fetal dose far below the safe level. Therefore, our additional shielding devices are useful and effective to reduce the fetal dose.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.129-136
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• 2009

Purpose: To determine optimal imaging time for diagnostic I-123 whole body scan in the follow-up of patients with differentiated thyroid cancer(DTC), we compared the image quality of 6- and 24-hour images of the same subjects. Materials and Methods: Four hundred ninety-eight patients(M:F = 55:443, Age $47.6{\pm}12.9$ years) with DTC who had undergone total thyroidectomy and I-131 ablation therapy underwent diagnostic whole body scanning 6 hour and 24 hour after oral ingestion of 185 MBq(5 mCi) of I-123. Serum thyroglobulin measurement and ultrasonography of the neck were performed at the time of imaging. In 40 patients underwent additional I-131 therapy, post-therapy I-131 images were obtained and compared with diagnostic I-123 images. Results: In 440 patients(88.4%), 6- and 24-hour diagnostic I-123 images were concordant, and 58 patients(11.6%) showed discordant findings. Among 58 discordant patients, 31 patients showed abnormal tracer uptake on only 6-hour image, which turned out false-positive findings in all cases. In 12 patients with positive findings on only 24-hour image, remnant thyroid tissue(4 patients) and cervical lymph node metastasis(3 patients) were presented. Among 40 patients underwent additional I-131 therapy, 6-hour and 24-hour images were discordant in 13 patients. All 5 patients with abnormal uptake on only 6-hour image revealed false-positive results, whereas most of 24-hour images were concordant with post-therapy I-131 images. Conclusion: I-123 imaging at 24-hour could reduce false-positive findings and improve diagnostic accuracy, compared with 6-hour image in the follow-up of patient with DTC.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.388-393
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• 1999

Background: Correct preoperative staging of esophageal cancer is a prerequisite for adequate treatment. We prospectively compared the accuracy of positron emission tomography (PET) with [fluorine-18]FDG in the staging of esophageal cancer to that of computed tomography (CT). Material and Method: The findings of FDG PET and of chest CT including lower neck and the upper abdomen of 20 biopsy-proven squamous cell carcinoma patients (male, 19; female, 1; mean age, 61) were compared with the pathologic findings obtained from a curative esophagectomy with lymph node dissection. Result: The sensitivities of FDG PET and CT for diagnosis of primary tumor were the same, 90.0% (18/20). Both FDG PET and CT failed to show the primary tumor in 2 of 20 patients; one had a 1cm sized carcinoma in situ and the other had T1 stage cancer. By using the results of the pathologic examinations of 193 removed lymph node groups, we calculated the diagnostic sensitivities, specificities and accuracies of PET and CT (*$\chi$2 p < 0.005). Sensitivity** Specificity Accuracy* PET 55.6%(30/54) 97.1%(135/139) 85.5%(165/193) CT 13.0%(7/54) 98.6%(137/139) 74.6%(144/193) One of four patients with a false-positive for PEThad had active pulmonary tuberculosis. Among the 24 tumor involved lymph node groups, PET failed to show tumor metastasis in 5 lymph node groups abutting the tumor and in 14 lymph node groups located where the decay correction was not performed. Conclusion: Based on the above findings, it is suggested that [F-18]FDG-PET is superior to CT in the detection of nodal metastases and in the staging of patients with esophageal cancer.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.150-156
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• 2000

Purpose : Stereotactic radiation therapy (SRT) can deliver highly focused radiation to a small and spherical target lesion with very high degree of mechanical accuracy. For non-spherical and large lesions, however, inclusion of the neighboring normal structures within the high dose radiation volume is inevitable in SRT This is to report the beam shaping using the partial closure of the independent jaw in SRT and the verification of dose calculation and the dose display using a home-made soft ware. Materials and Methods : Authors adopted the idea to partially close one or more independent collimator jaw(5) in addition to the circular collimator cones to shield the neighboring normal structures while keeping the target lesion within the radiation beam field at all angles along the arc trajectory. The output factors (OF's) and the tissue-maximum ratios (TMR's) were measured using the micro ion chamber in the water phantom dosimetry system, and were compared with the theoretical calculations. A film dosimetry procedure was peformed to obtain the depth dose profiles at 5 cm, and they were also compared with the theoretical calculations, where the radiation dose would depend on the actual area of irradiation. Authors incorporated this algorithm into the home-made SRT software for the isodose calculation and display, and was tried on an example case with single brain metastasis. The dose-volume histograms (DVH's) of the planning target volume (PTV) and the normal brain derived by the control plan were reciprocally compared with those derived by the plan using the same arc arrangement plus the independent collimator jaw closure. Results : When using 5.0 cm diameter collimator, the measurements of the OF's and the TMR's with one independent jaw set at 30 mm (unblocked), 15.5 mm, 8.6 mm, and 0 mm from th central beam axis showed good correlation to the theoretical calculation within 0.5% and 0.3% error range. The dose profiles at 5 cm depth obtained by the film dosimetry also showed very good correlation to the theoretical calculations. The isodose profiles obtained on the home-made software demonstrated a slightly more conformal dose distribution around the target lesion by using the independent jaw closure, where the DVH's of the PTV were almost equivalent on the two plans, while the DVH's for the normal brain showed that less volume of the normal brain receiving high radiation dose by using this modification than the control plan employing the circular collimator cone only. Conclusions : With the beam shaping modification using the independent jaw closure, authors have realized wider clinical application of SRT with more conformal dose planning. Authors believe that SRT, with beam shaping ideas and efforts, should no longer be limited to the small spherical lesions, but be more widely applied to rather irregularly shaped tumors in the intracranial and the head and neck regions.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.259-265
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• 1993

Between January 1985 and July 1992, 52 patients with locally advanced nasopharyngeal carcinoma were studied retrospectively for the effectiveness of sequential chemotherapy and radiation therapy. The male to female ratio was 3.3:1 with a median age of 41 years. Forty patients had squamous cell carcinoma and the remaining 12 had undifferentiated carcinoma. Seven patients had stage III disease and the remainder had stage IV disease at time of presentation. All patients were treated two courses of chemotherapy followed by radiation therapy. Chemotherapy consisted of either CVB (cisplatin, vincristine and bleomycin) or CF (cisplatin and 5-FU). Total radiation dose to the primary site ranged from 6000 cGy to 7500 cGy. Neck nodes were given booster treatment to maximum of 7000 cGy, depending on the extent of disease. Local control, overall survival and disease-free survival rates were analyzed. The complete response (CR) rate to chemotherapy was $15\%$ and the partial response (PR) rate was $46\%,$ for overall major response rate of $61\%.$ The CR rate was $87\%$ after radiation therapy. Median follow-up time was 51 months. The overall survival and disease-free survival rates at 36 months were $54\%\;and\;49\%,$ respectively. Median time to relapse was 15 months. The patterns of initial relapse in CR patients was as follows: locoregional failure only, 12 patients; distant metastasis only,11: both,2. Cox's multivariate regression model revealed that nodal status was the single most important independant prognostic factor influencing disease-free survival (p=0.001). Comparision of these results with other published reports with radiation therapy alone showed that a high rate of initial response to chemotherapy did not translate into local control or survival. At present time radiation therapy alone remains the standard treatment for locoregional cancer of the nasopharyngeal cancer. More controlled clinical trials must be completed before acceptance of chemotherapy as a part of treatment of advanced nasopharyngeal carcinoma.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.525-532
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• 1999

The parathyroid hormone related protein (PTHrP) is the most common causative peptide of humoral hypercalcemia of malignancy. In contrast, the serum level of parathyroid hormone (PTH) is low to undetectable in the majority of patients with malignancy associated hypercalcemia. Few cases exist in which the production and secretion of PTH by malignant nonparathyroid tumors have been authenticated. To our knowledge, there is very rare case in which a nonparathyroid tumor expressed simultaneously both the PTH and PTHrP. We report a case of squamous cell carcinoma of the lung with hypercalcemia which presented with simultaneous elevation of serum PTH and PTHrP. Severe hypercalcemia (serum calcium, 7.5 mEq/L) was found in a 65-year-old man who had a squamous cell carcinoma of the lung without any bony metastasis and detectable parathyroid abnormalities on isotope scintigraphy. The serum level of intact parathyroid hormone (PTH) con centration was markedly elevated as measured in two site radioimmunoreactive PTH assays (intact PTH 150 pg/mL ; normal 9~55). The serum level of a PTHrP was also increased as measured in C-terminal region specific radioimmunoassay (PTHrP 99.1 pmol/L; normal 13.8~55.3). There are no evidences of coincidental primary hyperparathyroidism in parathyroid MIBI scan and other imaging studies including neck ultrasonography and computed tomography. These results suggest that simultaneous elevation of serum PTH and PTHrP in this patient can be caused by production of both PTHrP and PTH in other nonparathyroid lesions such as squamous cell carcinoma.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.776-784
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• 1998

Background: The cyclin D1 gene is one of the most frequently amplified chromosomal regions(11q13) in human carcinomas. In laryngeal and head and neck carcinomas, its overexpression has been shown to be associated with advanced local invasion and presence of lymph node metastases. Cyclin D1 may therefore playa key role in cell growth regulation and tumorigenesis. Lung cancer is a worldwide problem and in many contries it is the most lethal malignancy. As relapse is frequent after resection of early stage non-small cell lung cancer, there is an urgent need to define prognostic factors. Purpose: This study was undertaken to evaluate the prognostic value of the cyclin D1, that is one the G1 cyclins which control cell cycle progression by allowing G1 to S phase transition, on the patients in radically resected non-small cell lung cancer. Method: Total 81 cases of formalin-fixed paraffin-embedded blocks from resected primary non-small cell lung cancer from January 1, 1983 to July 31, 1995 at Hanyang University Hospital were available for both clinical follow-up and immunohistochemical staining using monoclonal antibodies for cyclin D1. Results : The histologic classification of the tumor was based on WHO criteria, and the specimens included 45 squamous cell carcinomas, 25 adenocarcinomas and 11 large cell carcinomas. Cyclin D1 overexpression was noted in 26 cases of 81 cases tested (30.9%). Cyclin D1 expression was not significantly associated with cell types of the tumor, pathological staging and the size of the tumor. But cyclin D1 overexpression was significantly correlated with positive lymph node metastasis(p=0.035). The mean survival duration was $22.76{\pm}3.50$ months in cyclin D1 positive group and $45.38{\pm}5.64$ months in eyclin D1 negative group. There was a nearly significant difference in overall survival between cyclin D1 positive and negative groups(p=0.0515) in radically resected non-small cell lung cancer. Conclusion: Based on this study, cyelin D1 overexpression appears an important poor prognostic indicator in non-small cell lung cancer and may have diagnostic and prognostic importance in the treatment of resectable non-small cell lung cancer.