Antimicrobial Resistance Caused by KPC-2 Encoded by Promiscuous Plasmids of the Klebsiella pneumoniae ST307 Strain

Background@#A lineage of Klebsiella pneumoniae that produces carbapenemase-2 (KPC-2), sequence type (ST) 307, emerged in 2017. We analyzed the complete sequences of plasmids from KPC-2-producing K. pneumoniae (KPC-Kp) ST307, investigated the antimicrobial resistance conferred by this strain, and confirmed the horizontal interspecies transmission of KPC- carbapenemase-producing Enterobacteriaceae (CPE) characteristics among Enterobacteriaceae. @*Methods@#We performed antimicrobial susceptibility testing, PCR analysis, multilocus sequence typing, curing tests, and whole-genome sequencing to characterize plasmid-derived KPC-2-producing Enterobacteriaceae clinical isolates. @*Results@#Sequence analysis of KPC-Kp strain ST307 revealed novel plasmid-located virulence factors, including a gene cluster for glycogen synthesis. Three Enterobacteriaceae strains were identified in one patient: K. pneumoniae (CPKp1825), Klebsiella aerogenes (CPEa1826), and Escherichia coli (CPEc1827). The bla KPC-2 gene from K. pneumoniae ST307 was horizontally transmitted between these strains. The plasmids could be transferred through conjugation, because all three strains of bacteria contained the type IV secretion system, pilus genes, and tra genes for conjugal transfer. The bla KPC-2 gene was located on a truncated Tn4401 transposon. Plasmids containing the bla KPC-2 gene could not be artificially removed; thus, the three strains could not be cured. @*Conclusions@#The ease of horizontal transfer of KPC-Kp ST307 carbapenem resistance has serious public health and epidemiological implications. This study provides a better understanding of the genetic characteristics that can contribute to the growth and spread of KPC-Kp ST307, and their association with antimicrobial resistance genes.

Practical Output Dosimetry with Undefined NdwCo-60 of Cylindrical Ionization Chamber for High Energy Photon Beams of Linear Accelerator / 의학물리

For the determination of absorbed dose to water from a linear accelerator photon beams, it needs a exposure calibration factor Nx or air kerma calibration factor Nk of air ionization chamber. We used the exposure calibration factor Nx to find the absorbed dose calibration factors of water in a reference source through the TG-21 and TRS-277 protocol. TG-21 used for determine the absorbed dose in accuracy, but it required complex calculations including the chamber dependent factors. The authors obtained the absorbed dose calibration factor NdwCo-60 for reduce the complex calculations with unknown Ndw only with Nx or Nk calibration factor in a TM31010 (S/N 1055, 1057) ionization chambers. The results showed the uncertainty of calculated Ndw of IC-15 which was known the Nx and Ndw is within -0.6% in TG-21, but 1.0% in TRS-277. and TM31010 was compared the Ndw of SSDL to that of PSDL as shown the 0.4%, -2.8% uncertainty, respectively. The authors experimented with good agreement the calculated Ndw is reliable for cross check the discrepancy of the calibration factor with unknown that of TM31010 and IC-15 chamber.

Radiation Therapy for Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis / 대한방사선종양학회지

PURPOSE: To evaluate the effectiveness of radiation therapy (RT) for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) and to analyze the prognostic factors. MATERIALS AND METHODS: From December 2004 to April 2009, 70 patients who had HCC with PVTT were treated with RT at Keimyung University Dongsan Medical Center. Nineteen patients whose total dose was below 30 Gy and one patient who underwent liver transplantation were excluded. The remaining 50 patients (45 males, 5 females; median age 55 years) were analyzed. According to the LCSGJ TNM stage, there were 27 patients (54.0%) with stage III and 23 (46.0%) with stage IV. Total dose of 30~54 Gy was administered (median 45). Thirty patients (60.0%) were treated with concurrent chemoradiation therapy (CCRT). The median follow-up duration was from 13.5 months (range, 3 to 70 months). RESULTS: The median survival time from the start of RT was 9 months. One-year and 2-year overall survival rates were 24.9% and 11.2%, respectively. At the follow-up time, three patients (6.0%) displayed no evidence of disease. Seven patients (14.0%) were alive with disease, and 40 (80.0%) patients had expired due to disease progression. CCRT was associated with worse survival than RT alone (p=0.034). Response to RT (p=0.037), CLIP stage (p=0.017), and TNM stage (p=0.041) were statistically significant prognostic factors. There was no radiation-induced liver disease. CONCLUSION: RT is an effective and safe modality for HCC with PVTT. Further studies such as prospective randomized trials are needed to confirm the role of RT for HCC with PVTT.

Evaluation of the Output Dose of a Linear Accelerator Photon Beams by Using the Ionization Chamber TM31010 Series through TG-51 Protocol to Postal Monitoring Output of RPC for 5 Years / 의학물리

This study is to keep the accuracy and stability of the output dose evaluations for linear accelerator photon beams by using the air ionization chambers (TM31010, 0.125 cc, PTW) through the Task Group 51 protocol. The absorbed dose to water calibration factor NdwCo-60 was delivered from the air kerma calibration factor Nk which was provided from manufacture through SSDL calibration for determination of output factor. The ionization chamber of TM31010 series was reviewed the calibration factor and other parameters for reduce the uncertainty within +/-2% discrepancy and we found the supplied NdwCo-60 which was derived from Nk has shown a -2.8% uncertainty compare to that of PSDL. The authors provided the program to perform the output dosimetry with TG-51 protocol as it is composed same screen of TG-51 worksheets. The evaluated dose by determination of output factor delivered to postal TLD block for comparison the output dose to that of MDACC (RPC) in postal monitoring program. The results have shown the 1.001+/-0.013 for 6 MV and 0.997+/-0.012 discrepancy for 15 MV X rays for 5 years followed. This study shows the evaluated outputs for linear accelerate photon beams are very close to that of international output monitor with small discrepancy of +/-1.3% with high reliability and showing the gradually stability after 2010.

Development of Lead Free Shielding Material for Diagnostic Radiation Beams / 의학물리

The shielding materials designed for replacement of lead equivalent materials for lighter apron than that of lead in diagnostic photon beams. The absorption characteristics of elements were applied to investigate the lead free material for design the shielding materials through the 50 kVp to 110 kVp x-ray energy in interval of 20 kVp respectively. The idea focused to the effect of K-edge absorption of variable elements excluding the lead material for weight reduction. The designed shielding materials composited of Tin 34.1%, Antimon 33.8% and Iodine 26.8% and Polyisoprene 5.3% gram weight account for 84 percent of weight of lead equivalent of 0.5 mm thickness. The size of lead-free shielder was 200x200x1.5 mm3 and 3.2 g/cm3 of density which is equivalent to 0.42 mm of Pb. The lead equivalent of 0.5 mm thickness generally used for shielding apron of diagnostic X rays which is transmitted 0.1% for 50 kVp, 0.9% for 70 kVp and 3.2% for 90 kVp and 4.8% for 110 kVp in experimental measurements. The experiment of transmittance for lead-free shielder has showed 0.3% for 50 kVp, 0.6% for 70 kVp, 2.0% for 90 kVp and 4.2% for 110 kVp within 0.1%. respectively. Using the attenuation coefficient of experiments for 0.5 mm Pb equivalent of lead-free materials showed 0.1%. 0.3%, 1.0% and 2.4%, respectively. Furthermore, the transmittance of lead-free shielder for scatter rays has showed the 2.4% in operation energy of 50 kVp and 5.9% in energy of 110 kVp against 2.4% and 5.1% for standard lead thickness within 0.2% discrepancy, respectively. In this experiment shows the designed lead-free shielder is very effective for reduction the apron weight in diagnostic radiation fields.

Determination of Phantom Scatter Factors for Small Photon Fields / 의학물리

Total scatter factor (Scp), head scatter factor (Sc) and phantom scatter factor (Sp) are very important for accurate radiation therapy at stereotactic radiosurgery (SRS) with irregular field shape using micro-MLC and intensity modulated radiation therapy (IMRT) including many small field sizes. In this study we measured and compared Scp with reference ion chamber, pinpoint chamber and diode detector and adapted the resuls form diode detector. Head scatter factors for small field sizes were also measured with diode detector covered 1.5 cm-thick solid water build-up cap. Some errors like as electron contamination of 1~3% were included in the values of Sc but trend of total results of Sc was coincided with basic theory. Phantom scatter factors for small field sizes were calculated form Scp and Sc. The results of Sp were compared and were well-agreed with those of other authors.

Development of Source Template ICRT Dose Planning Software for Uterine Cervix Using the HDR: 192Ir / 의학물리

The source position and source dwelling time in a given source arrangement in the applicators is very high effect to determine the expose time which in general is derived from the brachytherapy planning system. In high dose rate (HDR) intracavitary radiation therapy (ICRT), the treatment is often performed in based out-patient during the whole fractionation irradiations. However, the patient should be waited on coutch for ICR treatment in first start fraction as unconvinent and immobilized state until perform the dose plannings. In our experiments, the HDR source contributed dose for 55.89+/-4.20% for straight tandem source, 38.14+/-4.46% for the right ovoid soucre on the fornix and 5.97+/-0.50% for left ovoid source. It also showed the 60.33+/-6.53% for the tandem, 33.10+/-6.74% for right ovoid and 6.58+/-0.30% for the left ovoid source in 10 degrees of applicator. The authors designed the source template dose planning software for ICRT of uterine cervix results average -0.55+/-2.15% discrepancy of the full charged brachytherapy dose planning. Developed Source temperate ICRT plaanning software guide a minimized the complains and operating times within a +/-3% of dose discrepancies.

Evaluation the Output Dose of Linear Accelerator Photon Beams by Blind Test with Dose Characteristics of LiF:Mg,Cu,P TLD / 의학물리

To achieve the accurate evaluation of given absorbed dose from output dose of linear accelerator photon beam through investigate the characteristics of LiF:Mg,Cu,P TLD powder. This experimental TL phosphor is performed with a commercial LiF:Mg,Cu,P powder (Supplied by PTW) and TL reader (LTM, France). The TLD was exposed to 6 MV X rays of linear accelerator photon beam with range 15 to 800 cGy in blind dose at two hospitals. The dose evaluation of TLD was through the experimental algorithms which were dose dependency, dose rate dependency, fading and powder weight dependency. The glow curve has shown the three peaks which are 110, 183 and 232 degrees of heating temperature and the main dosimetric peak showed highest TL response at 232 high temperature. In this experiments, the LiF:Mg,Cu,P phosphor has shown the 2.5 eV of electron trap energy with a second order. This experiments guided the dose evaluation accuracy is within 1% +2.58% of discrepancy. The TLD powder of LiF:Mg,Cu,P was analyzed to dosimetric characterists of electron captured energy and order by glow shape, and dose-TL response curve guided the accuracy within 1.0+2.58% of output dose discrepancy.

Compare the Clinical Tissue Dose Distributions to the Derived from the Energy Spectrum of 15 MV X Rays Linear Accelerator by Using the Transmitted Dose of Lead Filter / 의학물리

Recent radiotherapy dose planning system (RTPS) generally adapted the kernel beam using the convolution method for computation of tissue dose. To get a depth and profile dose in a given depth concerened a given photon beam, the energy spectrum was reconstructed from the attenuation dose of transmission of filter through iterative numerical analysis. The experiments were performed with 15 MV X rays (Oncor, Siemens) and ionization chamber (0.125 cc, PTW) for measurements of filter transmitted dose. The energy spectrum of 15 MV X-rays was determined from attenuated dose of lead filter transmission from 0.51 cm to 8.04 cm with energy interval 0.25 MeV. In the results, the peak flux revealed at 3.75 MeV and mean energy of 15 MV X rays was 4.639 MeV in this experiments. The results of transmitted dose of lead filter showed within 0.6% in average but maximum 2.5% discrepancy in a 5 cm thickness of lead filter. Since the tissue dose is highly depend on the its energy, the lateral dose are delivered from the lateral spread of energy fluence through flattening filter shape as tangent 0.075 and 0.125 which showed 4.211 MeV and 3.906 MeV. In this experiments, analyzed the energy spectrum has applied to obtain the percent depth dose of RTPS (XiO, Version 4.3.1, CMS). The generated percent depth dose from 6x6 cm2 of field to 30x30 cm2 showed very close to that of experimental measurement within 1% discrepancy in average. The computed dose profile were within 1% discrepancy to measurement in field size 10x10 cm, however, the large field sizes were obtained within 2% uncertainty. The resulting algorithm produced x-ray spectrum that match both quality and quantity with small discrepancy in this experiments.

Estimation of RTP Accuracy Based the International Reference Level / 의학물리

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.

Result of Radiation Therapy of Sino-nasal Cancers Using Partial Attenuation Filter / 대한방사선종양학회지

PURPOSE: This study was to evaluate the survival and pattern of failure after radiation therapy of sino-nasal cancer using partial attenuation filer and wedged beams and to help radiotherapy planning of sino-nasal cancer. MATERIALS AND METHODS: Between February 1992 and March 2003, 17 patients with sino-nasal cancers underwent radiation therapy using partial attenuation filter at Dongsan Medical Center, Keimyung university. There were 9 male and 8 female patients. Patients' age ranged from 40 to 75 years (median 59 years). There were 10 patients of maxillary sinus cancer, 7 patiens of nasal cancer. The histologic type was squamous cell carcinoma in 11, adenoid cystic carcinoma in 4 and olfactory neuroblastoma in 2. The distribution of clinical stage by the AJCC system was 3 for stage II, 7 for III and 6 for IV. The five patients were treated with radiation alone and 12 patients were treated with surgery and postoperative radiation therapy. The range of total radiation dose delivered to the primary tumor was from 44 to 76 Gy (median 60 Gy). The follow- up period ranged from 3 to 173 months with median of 78 months. RESULTS: The overall 2 year survival rate and disease free survival rate was 76.4%. The 5 year and 10 year survival rate were 76.4% and 45.6% and the 5 year and 10 year disease free survival rate was 70.6%. The 5 year disease free survival rate by treatment modality was 91.6% for postoperative radiation group and 20% for radiation alone group, statistical significance was found by treatment modality (p=0.006). There were no differences in survival by pathology and stage. There were local failure in 5 patients (29%) but no distant failure and no severe complication required surgical intervention. CONCLUSION: Radiation therapy of sino-nasal cancer using partial attenuation filter was safe and effective. Combined modality with conservative surgery and radiation therapy was more advisable to achieve loco-regional control in sino-nasal cancer. Also we considered high precision radiation therapy with dose escalation and development of multi-modality treatment to improve local control and survival rate in advanced sino-nasal cancer

Treatment of Early Glassy Cell Carcinoma of Uterine Cervix / 대한방사선종양학회지

PURPOSE: The purpose of this study was to investigate the clinical findings, treatment, and outcome of patients with glassy cell carcinoma of cervix. MATERIALS AND METHODS: We reviewed all cases of glassy cell carcinima of the uterine cervix confirmed and treated at the Dongsan Medical Center, Keimyung University, between January 1993 and December 2005. There were 7 cases with histopathologically confirmed gassy cell carcinoma. A tumor was diagnosed as glassy cell carcinoma if over 50% of the tumor cell type displayed glassy cell features. Six patients with stage IB had radical hysterectomy and bilateral pelvic node dissection, and 2 of them received adjuvant external pelvic irradiation with concurrent chemotherapy. Remaining one patient with stage IIA had curative concurrent chemoradiotherapy with external pelvic irradiation and brachytherapy. RESULTS: There were 7 patients diagnosed as glassy cell carcinoma among the 3,745 (0.2%) patients of carcinoma of uterine cervix. The mean age of 7 patients was 44 years with range of 35 to 53 years of age. The most frequent symptom was vaginal bleeding (86%). By the punch biopsy undertaken before treatment of 7 cases, 2 only cases could diagnose as glassy cell carcinoma of uterine cervix, but remaining of them confirmed by surgical pathological examination. The mean follow up duration was 73 months with range of 13 to 150 months. All 7 patients were alive without disease after treatment. CONCLUSION: Glassy cell carcinoma of the uterine cervix is a distinct clinicopathologic entity that demonstrates an aggressive biologic behavior. However for early-stage disease, we may have more favorable clinical outcome with radical surgery followed by chemoradiothery.

Malignant Melanoma of the Vagina: A Report of 2 Cases / 대한방사선종양학회지

Primary malignant melanoma of the vagina is an extremely rare genital neoplasm occurring mainly in postmenopausal women. It has a worse prognosis than cutaneous melanomas, because of the high rate of loco- regional recurrences and rapid systemic dissemination. In the past, radical surgical extirpation as the primary management had been recommended to improve loco-regional control, and possibly overall survival. However, the prognosis was poor in spite of such a radical approache. Recently, more conservative treatment such as wide local excision combined with adjuvant high-dose fraction radiotherapy seems to have promising results. Primary radiation therapy could be served as an alternative to surgery for patients with lesion less than 3 cm in diameter. We report 2 cases of primary vaginal malignant melanoma treated with radiotherapy.

Clinical Characteristics and Treatment Results of Neuroendocrine Carcinoma of Uterine Cervix / 대한방사선종양학회지

PURPOSE: To evaluate the clinical findings, prognosis and treatment strategy of patients with neuroendocrine carcinoma of cervix. MATERIALS AND MEHTODS: Thirteen patients with neuroendocrine carcinoma of cervix were included in this study, as confirmed histologically and immunohistochemically at the Dongsan Medical Center, Keimyung University, between May 1944 and October 2001. The mean age of patients was 56 years with a range of 32 to 78 years of age. According to the FIGO staging system, there were 5 patients with stage IB carcinoma, 5 patients with IIA, and 3 patients with stage IIB. Four patients underwent radical hysterectomy with pelvic lymphadenectomy, 3 of these patients also received postoperative radiotherapy, and one patient underwent extrafascial hysterectomy after radiotherapy. Primary radiotherapy was done in 9 patients, and 3 were irradiated postoperatively. Nine patients received chemotherapy, 7 received neoadjuvant and 2 received concurrent chemoradiotherapy. The radical purpose of radiotherapy consisted of external irradiation to the whole pelvis (4,500~5,400 cGy) and intracavitary irradiation (3,000~3,500 cGy). RESULTS: The mean follow up duration was 36 months with a range of 3 to 104 months. The overall 5-year survival rate was 61.5% and the 5-year survival rates for stage IB, IIA, IIB were 60.0%, 60.0%, and 66.7% respectively (p=0.99). Eight patients are still alive without disease, and all of the 5 patients with recurrence are dead due to distant metastasis. CONCLUSION: Neuroendocrine carcinoma of cervix is highly aggressive, with early lymphatic dissemination and a high rate of distant recurrence. Therefore, an aggressive therapeutic strategy is required to obtain pelvic and distant disease control. Multimodal therapy should be considered at the time of initial diagnosis.

Radiosurgery with Linac Based Photon Knife in Cerebral Arteriovenous Malformation / 대한방사선종양학회지

PURPOSE: The purpose of this study was to analyze the effect of a Linear accelerator based Photon Knife Radiosurgery System developed by the staff of Keimyung University Dongsan Medical Center for the treatment of cerebral arteriovenous malformation. Material and Methods:Between December 1993 and October 2000, 30 patients with cerebral arteriovenous malformation (AVM) were treated with the Linac based Photon Knife Radiosurgery System in the Department of Therapeutic Radiology at Keimyung University Dongsan Medical Center. The median age was 34, ranging from 7 to 63 years, with a 2:1 male to female ratio. The locations of the AVM nidi were the frontal lobe (motor cortex), parietal lobe, and the thalamus, in that order. The diameters of the AVM nidi ranged 1.2 to 5.5 cm with a mean of 2.9 cm, and target volumes of between 0.5 and 20.6 cc, with a mean of 6.8 cc. The majority of patients received radiation doses of between 1,500 and 2,500 cGy, with a mean of 2,000 cGy, at 80% the isodose line. Twenty-five patients were treated with one isocenter, 4 with two, and 1 with four. The follow-up radiological evaluations were performed with cranial computed tomogram (CT) or MRI between 6 month and one year interval, and if the AVM nidus had completely disappeared in the CT or MRI, we confirmed this was a complete obliteration, with a cerebral or magnetic resonance angiogram (MRA). The median follow-up period was 39 months with a range of 10 to 103 months. RESULTS: Twenty patients were radiologically followed up for over 20 months, with complete obliteration observed in 14 (70%). According to the maximal diameter, all four of the small AVM (3 cm), only one showed complete obliteration, and 5 showed partial obliteration, but 3 of these underwent further radiosurgery 3 years later. One who followed up for 20 months following further radiosurgery eventually showed complete obliteration. Ten patients with seizure symptoms had no recurrent seizure due to radiosurgery and medication. One of the eleven patients who suffered intracranial bleeding developed further bleeding at 9 and 61 months following the radiosurgery although complete obliteration was evevtually observed and the patient was managed in hospital then recovered. No patient suffered severe complications following the radiosurgery. CONCLUSION: The radiosurgery with Linac-based Photon Knife radiosurgery system, developed by the staff at our hospital, is a safe and effective treatment for AVM patients having diameters or volumes of less than 3 cm or 10 cm3, respectively, located in inoperable areas or who refused neurosurgery. We suggest that staged AVM radiosurgery may initially be considered, if the AVM target volume is above 10 cm3.

Development of Dose Planning System for Brachytherapy with High Dose Rate Using Ir-192 Source / 대한방사선종양학회지

PURPOSE: A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 3D dose distributions. MATERIALS AND METHODS: Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dose- volume histogram. RESULTS: The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a 200x200 (mm2) plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were 4.5~9.0% smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed 1~5% discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. CONCLUSION: This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.

Reirradiation in Rcurrent Cervical Cancer Following Definite Radiation Therapy / 대한방사선종양학회지

PURPOSE: To evaluate treatment results in terms of local control, complications and survival after reirraidiation in recurrent cervical cancer following definite radiation therapy. MATERIAL AND METHODS: From November 1987 through March 1998, eighteen patients with recurrent cervical cancer following definite radiation therapy were subsequently treated with reirradiation at Keimyung University Dongsan Medical Center. In regard to the initial FIGO stage, one patient was stage Ia, five were stage IIa, three were IIb, two were IIb and two were IVa. The age range was 37 to 79 years old with median age of 57. The time interval from initial definite radiation therapy to recurrence ranged from 6 to 122 months with a median of 58 months. The recurrent sites were the uterine cervix in seven patients, vagina in ten and pelvic lymph node in one. Reirradiation was performed with external radiation and intracavitary radiation in twelve patients, external radiation and implantation in four and external radiation alone in two. The range of external radiation dose was 2,100~5,400 cGy and the range of the total radiation dose was 3,780~8,550 cGy. The follow-up periods ranged from 8 to 20 months with median of 25 following reirradiation. RESULTS: Fourteen of eighteen patients (78%) had local control just after reirradiation. The two year disease free survival (2YDFS) rate was 53.6%. There were statistically significant differences in the 2YDFS according to both recurrent site (2YDFS 28.5% in uterine cervix, 71.4% in vagina, ( p=0.03)) and the total dose (2YDFS 71.8% in >6,000 cGy , 25% in < OR = 6,000 cGy, p=0.007). Seven of ten patients who were followed for more than 20 months remain alive and disease free (7/18, 39%). Patients treated with external radiation and intracavitary radiation had a higher rate of 2YDFS. Seven patients including 4 patients with no local control experienced local failure in the uterus or vagina and two patients died with distant metastasis. Complications included rectal bleeding in 3 patients, bowel obstruction treated with surgery in two, hematuria in one, radiation cystitis in two, soft tissue swelling in two and vaginal necrosis spontaneously healed in one. There was no statistical difference in complications according to the total dose or the time to recurrence from initial radiation. CONCLUSION: In patients with recurrence following definite radiation therapy in the uterine cervical cancer, reirradiation may be effective but requires an effort to reduce radiation induced severe complications.

Linac Based Radiosurgery for Cerebral Arteriovenous Malformations

No abstract available.

Result of Radiation Therapy and Extrafascial Hysterectomy in Bulky Stage lB, llA-B Carcinoma of the Uterine Cervix / 대한방사선종양학회지

PURPOSE: To evaluate the efficacy of tadiation therapy and eatrafascial hysterectomy in bulky stage lB,lla-B uterine cervix cancers. MATERIALS AND METHODS: Twenty four patients with bulky stage lB and llA-B carcinoma of the uterine cervix were treated with extrafascial hysterectomy following radiation therapy due to doubts of residual disease at Department of therapeutic radiology, Keimyung University, Dongsan Hospital , From April 1986 to December 1997. According to FIGO staging system, there were 7 Patients with stage lB, 9 patients with llA and 8 patients with llB stage whose median age was 45. Pathologic distribution showed 16 patients with squamous cell carcinoma and 8 with adenocarcinoma. Seven patients had tumors that are less than 5Cm in size 17 patients had tumors with larger than 5Cm.The mean interval between radiation therapy and extrafascial hysterectomy was 57 days. The radiation therapy consisted of irradition to the whole pelvis (180 cGy/fraction, Mean 4100 cGy)and parametrial boost ( for a mean total dose of 5000cGy) with midline shield (4x10Cm), followed by intracavitary irradiation up to 7500 cGy to point A (maximum 8500cGy). The maximum follow up duration was 107 months and mean follow up duration was 42 months. RESULTS: Ten out 24 patients (41.7%)had residual disease found at the time of eatrafascial hysterectomies. Five year Overall survival rate (5Y OSR) and five year disease free survival rate (5Y DFSR) were 63.6% and 62.5% respectively . Five year overall survial rate for stage lB and llA was 71.4% and 50% for stage llB. There was a significant difference in 5Y OSR and 5Y DFSR between patients with and those without residual disease (negative vs Positive, 83.3% vs. 40% (p=0.01), 83.3% vs36% (p=0.01) respectively). There was a notable tendency of better survival with adenocarcinoma than with squamous cell carcinoma (adenocarcinoma vs squamous cell carcinoma, 85.7% vs. 53.3% (p=0.1), 85.7% vs. 50.9% (p=0.1) of 5Y OSR and 5T DFS respectivey). Total dose to A point did not make a significant difference in survival rate or the existence of residual lesion ( or =7500 cGy). It was also noted that significantly more frequent local have occurred in patients with positive residual residual disease compared with negative residual disease (5/10 vs. 0/14, p=0.003). There was no death related to treatment. CONCLUSION:T here was no improvement of residual and to the overall survial rate in sqite of increased total dose to point A. We conclude that there is a possible beneficial of radiation therapy follow by extrafascial hysterectomy in survival for adenocarcinoma of bulky stage lB and llA-B uterine cervix. We need to this with follow up and large number of patients.

A Study on Expression of Ki-67 Antigen in Melanocytic Skin Lesions / 대한피부과학회지

BACKGROUND: Evaluation of the cell proliferation activity of neoplasm is useful in making a diagnosis and prognosis. Immunohistochemical staining using MIB1 monoclonal antibodies has recently been demonstrated to assess tumor cell proliferation activity easily, because it can be performed on paraffin-embedded specimens and is available in a retrospective study. OBJECTIVE: The purpose of this study to investigate (a) the use of Ki-67 antibodies in distinguising between benign melanocytic nevus and malignant melanoma, and (b) the correlation between the Ki-67 labelling index(positive number per 100cells) and histological parameters such as the Breslow index, Clarks level, mitotic rate(mitoses per 100cells) in malignant melanoma. METHOD: A total of 37 formalin-fixed, paraffin-embedded melanocytic skin lesions(benign melanocytic nevus 21; malignant melanoma 16) were stained with MIB1 using the one hour method. The values of the Ki-67 labelling index were measured in all the lesions. For each case of malignant melanoma, the Breslow index, Clarks level and mitotic rate were quantitatively evaluated. RESULT: The Ki-67 labelling index averaged 2.6 +1.4 in benign melanocytic nevus and 22.4+ 6.2 in malignant melanoma. In malignant melanoma, the values of the Ki-67 labelling index were significantly correlated with Breslow index(r=0.764), Clark's level(r=0.885) and mitotic rate(r=0.754). CONCLUSION: Our findings suggest that Ki-67 may be a useful tool in distinguising between benign melanocytic nevus and malignant melanoma. According as Ki-67 labelling index correlates with well-established prognostic parameters(Breslow index, Clark's level, mitotic rate), it may therefore carry additional prognostic value for patients with malignant melanoma.