• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.285-293
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• 2017

Globally, 1.3 million people develop colon cancer every year, and 600,000 people die each year it. In Korea, colorectal carcinoma was associated with the highest death rate, accounting for 8,380 people, among solid cancers in 2015. Among the various methods for the diagnosis and study of colorectal carcinoma, the results obtained by cytogenetic and molecular genetic methods were compared. Detection rate was 47% in 18q, 40% in 17p, 27% in 22q, and 17% in 10q via CGH; detection rate was 57% in D18S59, 50% in D18S68, 50% in TP53CA, 47% in D18S6940% in D22S274, 37% in D22S283, 27% in D10S187, and 23% in D10S541 with LOH. Microsatellite marker matching rates were 100% in D22S274, 100% in D22S283, 100% in D10S186, 100% in D10S187, 100% in D10S541, 93% in D18S69, 93% in D18S68, 92% in TP53CA, and 89% in D18S59. The agreement rate between the two methods was 94.4% based on positive results using CGH. Based on the advantages of CGH, which was the ability to obtain information regarding the entire tumor genome at once, this experiment could identify the region with significant deletion using CGH and the more limited region LOH, with a completely different approach. LOH in the recurrent high-risk group, 18q21, was helpful in the selection of treatment modalities and in prognostic estimation as well as making the most appropriate decision for treatment. Therefore, it is suggested that LOH with surgical site tissues could be one of the treatment methods for recurrent high-risk group among patients with colorectal carcinoma.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.77-85
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• 2013

Purpose: The accurate movement of gantry rotation, collimator and correct application of dose rate are very important to approach the successful performance of Volumetric Modulated Arc Therapy (VMAT), because it is tightly interlocked with a complex treatment plan. The interruption and restart of dose delivery, however, are able to occur on treatment by various factors of a treatment machine and treatment plan. If unexpected problems of a treat machine or a patient interrupt the VMAT, the movement of treatment machine for delivering the remaining dose will be restarted at the start point. In this investigation, We would like to know the effect of interruptions and restart regarding dose delivery at VMAT. Materials and Methods: Treatment plans of 10 patients who had been treated at our center were used to measure and compare the dose distribution of each VMAT after converting to a form of digital image and communications in Medicine (DICOM) with treatment planning system (Eclipse V 10.0, Varian, USA). We selected the 6 MV photon energy of Trilogy (Varian, USA) and used OmniPro I'mRT system (V 1.7b, IBA dosimetry, Germany) to analyze the data that were acquired through this measurement with two types of interruptions four times for each case. The door interlock and the beam-off were used to stop and then to restart the dose delivery of VMAT. The gamma index in OmniPro I'mRT system and T-test in Microsoft Excel 2007 were used to evaluate the result of this investigation. Results: The deviations of average gamma index in cases with door interlock, beam-off and without interruption on VMAT are 0.141, 0.128 and 0.1. The standard deviations of acquired gamma values are 0.099, 0.091, 0.071 and The maximum gamma value in each case is 0.413, 0.379, 0.286, respectively. This analysis has a 95-percent confidence level and the P-value of T-test is under 0.05. Gamma pass rate (3%, 3 mm) is acceptable in all of measurements. Conclusion: As a result, We could make sure that the interruption of this investgation are not enough to seriously affect dose delivery of VMAT by analyzing the measured data. But this investigation did not reflect all cases about interruptions and errors regarding the movement of a gantry rotation, collimator and patient So, We should continuously maintain a treatment machine and program to deliver the accurate dose when we perform the VMAT for the many kinds of cancer patients.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.9-14
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• 2013

Purpose: High-energy radiotherapy with 10 MV or higher develops photoneutron through photonuclear reaction. Photoneutron has higher radiation weighting factor than X-ray, thus low dose can greatly affect the human body. An accurate dosimetric calculation and consultation are needed. This study compared and analyzed the dose change of photoneutron in terms of space according to the size of photon beam energy and treatment methods. Materials and Methods: To measure the dose change of photoneutron by the size of photon beam energy, patients with the same therapy area were recruited and conventional plans with 10 MV and 15 MV were each made. To measure the difference between the two treatment methods, 10 MV conventional plan and 10 MV IMRT plan was made. A detector was placed at the point which was 100 cm away from the photon beam isocenter, which was placed in the center of $^3He$ proportional counter, and the photoneutron dose was measured. $^3He$ proportional counter was placed 50 cm longitudinally superior to and inferior to the couch with the central point as the standard to measure the dose change by position changes. A commercial program was used for dose change analysis. Results: The average integral dose by energy size was $220.27{\mu}Sv$ and $526.61{\mu}Sv$ in 10 MV and 15 MV conventional RT, respectively. The average dose increased 2.39 times in 15 MV conventional RT. The average photoneutron integral dose in conventional RT and IMRT with the same energy was $220.27{\mu}Sv$ and $308.27{\mu}Sv$ each; the dose in IMRT increased 1.40 times. The average photoneutron integral dose by measurement location resulted significantly higher in point 2 than 3 in conventional RT, 7.1% higher in 10 MV, and 3.0% higher in 15 MV. Conclusion: When high energy radiotherapy, it should consider energy selection, treatment method and patient position to reduce unnecessary dose by photoneutron. Also, the dose data of photoneutron needs to be systematized to find methods to apply computerization programs. This is considered to decrease secondary cancer probabilities and side effects due to radiation therapy and to minimize unnecessary dose for the patients.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.57-67
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• 2013

Purpose: Replacing the film which used to be used for checking the set-up of the patient and dosimetry during radiation therapy, more and more EPID equipped devices are in use at present. Accordingly, this article tried to evaluated the accuracy of the position check-up and the usefulness of dosimetry during the use of an electronic portal imaging device. Materials and Methods: On 50 materials acquired with the search of Korea Society Radiotherapeutic Technology, The Korean Society for Radiation Oncology, and Pubmed using "EPID", "Portal dosimetry", "Portal image", "Dose verification", "Quality control", "Cine mode", "Quality - assurance", and "In vivo dosimetry" as indexes, the usefulness of EPID was analyzed by classifying them as history of EPID and dosimetry, set-up verification and characteristics of EPID. Results: EPID is developed from the first generation of Liquid-filled ionization chamber, through the second generation of Camera-based fluoroscopy, and to the third generation of Amorphous-silicon EPID imaging modes can be divided into EPID mode, Cine mode and Integrated mode. When evaluating absolute dose accuracy of films and EPID, it was found that EPID showed within 1% and EDR2 film showed within 3% errors. It was confirmed that EPID is better in error measurement accuracy than film. When gamma analyzing the dose distribution of the base exposure plane which was calculated from therapy planning system, and planes calculated by EDR2 film and EPID, both film and EPID showed less than 2% of pixels which exceeded 1 at gamma values (r%>1) with in the thresholds such as 3%/3 mm and 2%/2 mm respectively. For the time needed for full course QA in IMRT to compare loads, EDR2 film recorded approximately 110 minutes, and EPID recorded approximately 55 minutes. Conclusion: EPID could easily replace conventional complicated and troublesome film and ionization chamber which used to be used for dosimetry and set-up verification, and it was proved to be very efficient and accurate dosimetry device in quality assurance of IMRT (intensity modulated radiation therapy). As cine mode imaging using EPID allows locating tumors in real-time without additional dose in lung and liver which are mobile according to movements of diaphragm and in rectal cancer patients who have unstable position, it may help to implement the most optimal radiotherapy for patients.

• Investigative Magnetic Resonance Imaging
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• v.9 no.2
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• pp.101-108
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• 2005

Purpose : Early detection of small brain metastases is important. The purpose of this study was to compare the detectability of brain metastases according to the size between 1.5 T and 3.0 T MRI. Materials and Methods : We reviewed 162 patients with primary lung cancer who were examined for TNM staging. After administration of double dose of Gd-DTPA, MR imaging was performed with SPGR by 3.0 T MRI and then with T1 SE sequence by 1.5 T MRI. In each patient, three readers performed qualitative assessment. Sensitivity, positive predictive value, and diagnostic accuracy were calculated in 3.0 T and 1.5 T MRI according to size. Using the signal intensity (SI) measurements between the metastatic nodules and adjacent tissue, nodule-to-adjacent tissue SI ratio was calculated. Results : Thirty-one of 162 patients had apparent metastatic nodules in the brain at either 1.5 T or 3.0 T MR imaging. 143 nodules were detected in 3.0 T MRI, whereas 137 nodules were detected at 1.5 T MRI. Six nodules, only detected in 3.0 T MRI, were smaller than 3.0 mm in dimension. Sensitivity, positive predictive value, and diagnostic accuracy in 3.0 T MRI were 100 %, 100 %, and 100 % respectively, and in 1.5 T MRI were 95.8%, 88.3%, and 85.1% respectively. SI ratio was significantly higher in the 3.0 T MRI than 1.5 T MRI (p=0.025). Conclusion : True positive rate of 3.0 T MRI with Gd-DTPA was superior to 1.5 T MRI with Gd-DTPA in detection of metastatic nodules smaller than 3.0 mm.

• Investigative Magnetic Resonance Imaging
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• v.9 no.2
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• pp.109-116
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• 2005

Purpose : To determine the usefulness of additional Mn-DPDP MRI for preoperative evaluation of the patients with colorectal cancers by comparison of dual-phase CT scan, Mn-DPDP enhanced MRI and combination of CT and MRI. Materials and Methods : Fifty-three colorectal cancer patients with 92 metastatic nodules underwent dualphase (arterial and portal) helical CT scan and Mn-DPDP MRI prior to surgery. The indication of MRI was presence or suspected of having metastatic lesions at CT scan and/or increased serum carcinoembryonic antigen (CEA) levels (10 ng/mL or more). The diagnosis was established by the combination of findings at surgery, intraoperative ultrasonography, and histopathologic examination. Two radiologists interpreted CT, MRI, and combination of CT-MRI at discrete sessions and evaluated each lesion for location, size, and intrinsic characteristics. The lesions were divided into three groups according to their diameter; 1cm<, 1-2 cm, and >2 cm. Diagnostic accuracy was evaluated using the alternative-free response receiver operating characteristic method. Detection and false positive rate were also evaluated. Results : In the lesions smaller than 1 cm, detection rate of combined CT-MRI was superior to CT or MRI alone (82%, p=0.036). The mean accuracy (Az values) of combined CT and MRI was significantly higher than that of CT in the lesions smaller than 2 cm (1 cm<, p=0.034; 1-2 cm, p=0.045). However, there was no significant difference between MRI and combined CT-MRI. The false positive rate of CT was higher than those of combined CT-MR in the lesions smaller than 1 cm (28%, p=0.023). Conclusion : Additional MRI using Mn-DPDP besides routine CT scan was helpful in differentiating the hepatic lesions (<2 cm) and could improve detection of the small hepatic metastases (<1 cm) from colorectal carcinoma.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.353-364
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• 2000

Background : Bronchoscopy is a useful diagnostic tool, for accurate localization of the bleeding site and the management of hemoptysis. However, there is some controversy about the optimal timing of bronchoscopy. Method : To determine the optimal timing of bronchoscopy in hemoptysis, we reviewed the medical records of 118 patients and analyzed the following relationships amongst simple chest PA findings, namely, the duration and amount of hemoptysis, and the timing of bronchoscopy retrospectively. Results : The major causes of hemoptysis were active tuberculosis(28.8%), inactive tuberculosis(10.2%), bronchiectasis(17.0%), lung cancer(7.6%), and aspergilloma(7.6%). Localization of the bleeding focus by bronchoscopy was possible in 87.5% (21/24 cases) during active bleeding, and it was possible in 40.4% after bleeding had stopped(p<0.05). The localization rate of bleeding focus was 59.8% when the chest PA showed certain abnormalities, but it decreased to 27.8% when the chest PA finding was normal(p<0.05). When chest PA showed diffuse abnormalities or its finding was normal, the localization rate of bleeding focus significantly increased if bronchoscopy was performed during bleeding or within 48 hours of the cessation of active bleeding. The localization rate was higher as the amount of hemoptysis became larger(p<0.05). The localization rate of early bronchoscopy(during bleeding or within 48 hours of the cessation of active bleeding) was significantly higher when the duration of hemoptysis was less than 1 week, but there was no advantage if the duration was 1 week or longer. Early bronchoscopy was also necessary to localize the bleeding focus for surgical resection in 4 patients, and the bronchoscopy itself was therapeutic in 1 patient whose bleeding was successfully managed with thrombin-application via bronchoscope. Conclusion : It is concluded that flexible bronchoscopy is useful at not only localizing the bleeding focus but also in preparing a therapeutic plan, and early bronchoscopy is more favorable in hemoptysis.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.309-315
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• 2006

Purpose: Accurate evaluation of cervical lymph node (LN) metastasis of head and neck squamous cell canter (SCC) is important to treatment planning. We evaluated the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the detection of cervical LN metastasis of head and neck SCC and performed a retrospective comparison with CT/MRI findings. Materials & Methods: Seventeen patients with pathologically proven head and neck SCC underwent F-18 FDG PET/CT and CT/MRI within 4 week before surgery. We recorded lymph node metastases according to the neck level system of imaging-based nodal classification. F-18 FDG PET/CT images were analyzed visually for assessment of regional tracer uptake in LN. We analyzed the differences in sensitivity and specificity between F-18 FDG PET/CT and CT/MRI using the Chi-square test. Results: Among the 17 patients, a total of 123 LN levels were dissected, 29 of which showed metastatic involvement. The sensitivity and specificity of F-18 FDG PET/CT for detecting cervical LN metastasis on a level-by-level basis were 69% (20/29) and 99% (93/94). The sensitivity and specificity of CT/MRI were 62% (18/29) and 96% (90/94). There was no significant difference in diagnostic accuracy between F-18 FDG PET/CT and CT/MRI. Interestingly, F-18 FDG PET/CT detected double primary tumor (hepatocellular carcinoma) and rib metastasis, respectively. Conclusion: There was not statistically significant difference of diagnostic accuracy between F-18 FDG PET/CT and CT/MRI for the detection of cervical LN metastasis of head and neck SCC. The low sensitivity of F-18 FDG PET/CT was due to limited resolution for small metastatic deposits.

• Radiation Oncology Journal
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• v.16 no.2
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• pp.167-175
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• 1998

Purpose : It is not a simple task to achieve the ideal isodose curve with a standard vaginal applicator or sing1e plane needle impant in the paravaginal tissue when primary or recurrent gynecological neoplasms(cervical cancers, vaginal cancers and vulvar cancers) are treated as a boost following external beam radiotherapy. The authors introduce the development and construction of a simple, inexpensive, customized applicator for volume implant to maximize the radiation dose to the tumor while minimizing the dose to the rectum and the bladder. Materials and Methods : Nine patients underwent Ir-192 transperineal interstitial implantation for either recurrent(5 cases) or primary(3 cases) cervical cancers or primary vaginal cancer(1 case) between August 1994 and February 1998 at Ajou university hospital. First 3 cases were performed with a sing1e plane implant guided by digital palpation. Because of inadequate isodose coverage in the tumor volume in first 3 cases, we designed and constructed interstitial vaginal applicator for volume implant to improve tumor dose distribution and homogeneity while sparing the surrounding normal tissue. Our applicators consist of vaginal obturator and perineal template that made of the clear acrylamide and dental mold material$(Provil^{(R)})$. The applicators were customized individually according to the tumor size and its location Both HDR and LDR irradiation were given with these applicators accomodating 6 Fr needles(Microselectron Nucletron). The pretreatment planning prior to actual implant was performed whenever possible. Results : Needles can be inserted easily and evenly into the tumor volume through the holes of templates, requiring less efforts and time for the implant procedure. Our applicators made of materials available from commercial vendors. These have an advantage that require easy procedure, and spend relatively short time to construct. Also it was possible to fabricate applicators to individualize according to the tumor size and its location and to achieve the ideal isodose coverage. We found an accurate needle arrangement and ideal dose distribution through the CT scan that was obtained in 3 cases after needle implant. Three patients with primary cervical and vaginal cancers were controlled locally at final follow up. But all recurrent cases failed to do so. Conclusion : The authors introduce inexpensive, simple interstitial vaginal templates which were self-designed and constructed using materials available from commercial vendors such as acrylanide and dental mold material $(Provil^{(R)})$.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.387-395
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• 1993

To identify pretreatment prognostic factors in carcinoma of the uterine cervix, a retrospective analysis was undertaken of 510 patients treated with curative radiation therapy in Seoul National University Hospital during the 7 year period, from March 1979 through December 1986. According to FIGO classification,35 patients were stage I B,89 were stage IIA, 232 were stage IIB,8 were stage IIIA, 134 were IIIB, and 12 were stage IVA. Five year locoregional control (LRC) rates in stage I B, II A, II B, IIIA, IIIB, and IVA were $79\%,78\%,70\%,58\%,51\%\;and\;27\%,$ respectively. Five year disease free survival (DFS) rates were $76\%,67\%,60\$,57\%,40\%,\;and\;25\%,$ respectively. Overall survival (OS) rates at five years were $82\%,72\%,67\%,67\%,51\%,\;and\;33\%,$ respectively. In univariate analyses, stage, age, initial hemoglobin level, type of histology, tumor size, and several CT findings including pelvic lymph node (LN) status, paraaortic lymph node (PAN) status, extent of parametrial invasion, bladder invasion, and rectal invasion were significant factors in terms of LRC. All these factors and elevation of BUN or creatinine were associated with DFS. In terms of overall survival, stage, initial hemoglobin level, type of histology, tumor size, elevation of BUN or creatinine, and five CT findings associated with LRC were prognostically significant. In multivariate analysis excluding CT findings, stage IV disease, non-squamous histology, and tumor size $\ge$4 cm were associated with poor LRC and DFS. Stage IV disease and tumor size significantly affected OS. in multivariate analysis including CT findings, histology, tumor size, and pelvic LN status on CT were uniformly significant in terms of LRC, DFS, and 05, PAN status on CT affected overall survival only.