Three-dimensional dose reconstruction-based pretreatment dosimetric verification in volumetric modulated arc therapy for prostate cancer

Purpose@#We performed three-dimensional (3D) dose reconstruction-based pretreatment verification to evaluate gamma analysis acceptance criteria in volumetric modulated arc therapy (VMAT) for prostate cancer. @*Materials and Methods@#Pretreatment verification for 28 VMAT plans for prostate cancer was performed using the COMPASS system with a dolphin detector. The 3D reconstructed dose distribution of the treatment planning system calculation (TC) was compared with that of COMPASS independent calculation (CC) and COMPASS reconstruction from the dolphin detector measurement (CR). Gamma results (gamma failure rate and average gamma value [GFR and γAvg]) and dose-volume histogram (DVH) deviations, 98%, 2% and mean dose-volume difference (DD98%, DD2% and DDmean), were evaluated. Gamma analyses were performed with two acceptance criteria, 2%/2 mm and 3%/3 mm. @*Results@#The GFR in 2%/2 mm criteria were less than 8%, and those in 3%/3 mm criteria were less than 1% for all structures in comparisons between TC, CC, and CR. In the comparison between TC and CR, GFR and γAvg in 2%/2 mm criteria were significantly higher than those in 3%/3 mm criteria. The DVH deviations were within 2%, except for DDmean (%) for rectum and bladder. @*Conclusions@#The 3%/3 mm criteria were not strict enough to identify any discrepancies between planned and measured doses, and DVH deviations were less than 2% in most parameters. Therefore, gamma criteria of 2%/2 mm and DVH related parameters could be a useful tool for pretreatment verification for VMAT in prostate cancer.

Multi-institutional analysis of T3 subtypes and adjuvant radiotherapy effects in resected T3N0 non-small cell lung cancer patients

PURPOSE: We evaluated the prognostic significance of T3 subtypes and the role of adjuvant radiotherapy in patients with resected the American Joint Committee on Cancer stage IIB T3N0M0 non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: T3N0 NSCLC patients who underwent resection from January 1990 to October 2009 (n = 102) were enrolled and categorized into 6 subgroups according to the extent of invasion: parietal pleura chest wall invasion, mediastinal pleural invasion, diaphragm invasion, separated tumor nodules in the same lobe, endobronchial tumor <2 cm distal to the carina, and tumor-associated collapse. RESULTS: The median overall survival (OS) and disease-free survival (DFS) were 55.3 months and 51.2 months, respectively. In postoperative T3N0M0 patients, the tumor size was a significant prognostic factor for survival (OS, p = 0.035 and DFS, p = 0.035, respectively). Patients with endobronchial tumors within 2 cm of the carina also showed better OS and DFS than those in the other T3 subtypes (p = 0.018 and p = 0.016, respectively). However, adjuvant radiotherapy did not cause any improvement in survival (OS, p = 0.518 and DFS, p = 0.463, respectively). Only patients with mediastinal pleural invasion (n = 25) demonstrated improved OS and DFS after adjuvant radiotherapy (n = 18) (p = 0.012 and p = 0.040, respectively). CONCLUSION: The T3N0 NSCLC subtype that showed the most favorable prognosis is the one with endobronchial tumors within 2 cm of the carina. Adjuvant radiotherapy is not effective in improving survival outcome in resected T3N0 NSCLC.

The Effect of Autophagy to Cell Death in Nutrient-Deprived H460 Cells / 결핵및호흡기질환

BACKGROUND: Autophagy is an important adaptive mechanism in normal development and in response to changing environmental stimuli in cancer. Previous papers have reported that different types of cancer underwent autophagy to obtain amino acids as energy source of dying cells in nutrient-deprived conditions. However, whether or not autophagy in the process of lung cancer causes death or survival is controversial. Therefore in this study, we investigated whether nutrient deprivation induces autophagy in human H460 lung cancer cells. METHODS: H460, lung cancer cells were incubated in RPMI 1640 medium, and the starved media, which are BME and RPMI media without serum, including 2-deoxyl-D-glucose according to time dependence. To evaluate the viability and find out the mechanism of cell death under nutrient-deprived conditions, the MTT assay and flow cytometry were done and analyzed the apoptotic and autophagic related proteins. It is also measured the development of acidic vascular organelles by acridine orange. RESULTS: The nutrient-deprived cancer cell is relatively sensitive to cell death rather than normal nutrition. Massive cytoplasmic vacuolization was seen under nutrient-deprived conditions. Autophagic vacuoles were visible at approximately 12 h and as time ran out, vacuoles became larger and denser with the increasing number of vacuoles. In addition, the proportion of acridine orange stain-positive cells increased according to time dependence. Localization of GFP-LC3 in cytoplasm and expression of LC-3II and Beclin 1 were increased according to time dependence on nutrient-deprived cells. CONCLUSION: Nutrient deprivation induces cell death through autophagy in H460 lung cancer cells.

Study on the Compatibility for an Ir-192 Source Manufactured by Korea Atomic Energy Research Institute (KAERI) in GammaMed Brachytherapy Machine / 의학물리

The compatibility with GammaMed-12i brachytherapy machine for an Ir-192 encapsulated source (IRRS20, KAERI, Korea) manufactured by Korea atomic energy research institute (KAERI) has been investigated. As a mechanical testing of compatibility, precise measurement of step movement with channels, measurement of curvature of radius for wire, and emergency return testing were performed. Periodic measurements of air kerma strength for 45 days were carried out to evaluate decay characteristics of Ir-192 radioisotope and comparison of dose distributions in phantom between KAERI and old sources previously used were performed by film dosimetry. KAERI source has a good compatibility with GammaMed12i machine as a result of mechanical testing. There are in good agreement with calculated values in activity characteristics and there were small differences in dose distributions around the source in comparison between KAERI and old source.

Induction of Autophagy by Low Dose of Cisplatin in H460 Lung Cancer Cells / 결핵및호흡기질환

BACKGROUND: Most lung cancer patients receive systemic chemotherapy at an advanced stage disease. Cisplatin-based chemotherapy is the main regimen for treating advanced lung cancer. Recently, autophagy has become an important mechanism of cellular adaptation under starvation or cell oxidative stress. The purpose of this study was to determine whether or not autophagy can occurred in cisplatin-treated lung cancer cells. METHODS: H460 cells were incubated with RPMI 1640 and treated in 5 micrometer or 20 micrometer cisplatin concentrations at specific time intervals. Cells surviving cisplatin treatment were measured and compared using an MTT cell viability assay to cells that underwent apoptosis with autophagy by nuclear staining, apoptotic or autophagic related proteins, and autophagic vacuoles. The development of acidic vascular organelles was using acridine orange staining and fluorescent expression of GFP-LC3 protein in its transfected cells was observed to evaluate autophagy. RESULTS: Lung cancer cells treated with 5 micrometer cisplatin-treated were less sensitive to cell death than 20 micrometer cisplatin-treated cells in a time-dependent manner. Nuclear fragmentation at 5 micrometer was not detected, even though it was discovered at 20 micrometer. Poly (ADP-ribose) polymerase cleavages were not detected in 5 micrometer within 24 hours. Massive vacuolization in the cytoplasm of 5 micrometer treated cells were observed. Acridine orange stain-positive cells was increased according in time-dependence manner. The autophagosome-incorporated LC3 II protein expression was increased in 5 micrometer treated cells, but was not detected in 20 micrometer treated cells. The expression of GFP-LC3 were increased in 5 micrometer treated cells in a time-dependent manner. CONCLUSION: The induction of autophagy occurred in 5 micrometer dose of cisplatin-treated lung cancer cells.

Induction of Autophagy by Low Dose of Cisplatin in H460 Lung Cancer Cells / 결핵및호흡기질환

BACKGROUND: Most lung cancer patients receive systemic chemotherapy at an advanced stage disease. Cisplatin-based chemotherapy is the main regimen for treating advanced lung cancer. Recently, autophagy has become an important mechanism of cellular adaptation under starvation or cell oxidative stress. The purpose of this study was to determine whether or not autophagy can occurred in cisplatin-treated lung cancer cells. METHODS: H460 cells were incubated with RPMI 1640 and treated in 5 micrometer or 20 micrometer cisplatin concentrations at specific time intervals. Cells surviving cisplatin treatment were measured and compared using an MTT cell viability assay to cells that underwent apoptosis with autophagy by nuclear staining, apoptotic or autophagic related proteins, and autophagic vacuoles. The development of acidic vascular organelles was using acridine orange staining and fluorescent expression of GFP-LC3 protein in its transfected cells was observed to evaluate autophagy. RESULTS: Lung cancer cells treated with 5 micrometer cisplatin-treated were less sensitive to cell death than 20 micrometer cisplatin-treated cells in a time-dependent manner. Nuclear fragmentation at 5 micrometer was not detected, even though it was discovered at 20 micrometer. Poly (ADP-ribose) polymerase cleavages were not detected in 5 micrometer within 24 hours. Massive vacuolization in the cytoplasm of 5 micrometer treated cells were observed. Acridine orange stain-positive cells was increased according in time-dependence manner. The autophagosome-incorporated LC3 II protein expression was increased in 5 micrometer treated cells, but was not detected in 20 micrometer treated cells. The expression of GFP-LC3 were increased in 5 micrometer treated cells in a time-dependent manner. CONCLUSION: The induction of autophagy occurred in 5 micrometer dose of cisplatin-treated lung cancer cells.

Quality Correction for Ir-192 Gamma Rays in Air Kerma Strength Dosimetry Using Cylindrical Ionization Chambers / 의학물리

The quality correction in the air kerma dosimetry for Ir-192 using farmer type ionization chambers calibrated by Co-60 quality is required. In this study we determined quality factor (kappa u) of two ionization chambers of PTW-N30001 and N23333 for Ir-192 source using dosimetric method. The quality factors for energy spectrum of microSelectron were determined as kappa u=1.016 and 1.017 for PTW-N30001 and N23333 ionization chambers respectively. We applied quality factors in air kerma dosimetry for microSelectron source and compared with reference values. As a results we found that the differences between reference air kerma rate and measured it with and without quality correction were about -0.5% and -2.0% respectively.

Commissioning of a micro-MLC (mMLC) for Stereotactic Radiosurgery / 의학물리

The 4 bank mico-MLC (mMLC; Acculeaf, Direx, Isral) has been commissioned for clinical use of linac based stereotactic radiosurgery. The geometrical parameters to control the leaves were determined and comparisons between measured and calculated by the calculation model were performed in terms of absolute dose (cGy/100 MU). As a result of evaluating calculated dose for various field sizes and depths of 5 and 10 cm in water in the geometric condition of fixed SSD (source to surface distance) and fixed SCD (source to chamber distance), most of differences were within 1% for 6 MV and 15 MV x-rays. The penumbral widths at the isocenter were approximately evaluated to 0.29~0.43 cm depending on the field size for 6 MV and 0.36~0.51 cm for 15 MV x-rays. The average transmission and leakage for 6 MV and 15 MV x-rays were 6.6% and 7.4% respectively in single level of leaves fully closed. In case of dual level of leaves fully closed the measured transmission is approximately 0.5% for both 6 MV and 15 MV x-rays. Through the commissiong procedure we could verify the dose characteristics of mMLC and approximately evaluate the error ranges for treatment planning system.

Study on the Dose Characteristics of the PTW-LinaCheck Dosimeter and Its Application to Daily Output Measurement / 의학물리

In this study, we have investigated the dose characteristics of PTW-LinaCheck designed to detect output of medical LINAC and discussed clinical use of the detector. The reproducibility, linearity, and dose rate dependency of the dosimeter were measured for photons of 6 and 15 MV and the electrons of 4, 6, 9, 12, and 16 MeV. To know the error ranges of the measured data in daily output measurement, the response variations due to geometrical setup errors were measured. As a result of measurement, the error range from the geometrical setup and the reproducibility was less than +/-0.6% for given beam qualities in daily output measurement, where the errors from the linearity and the dose rate dependency were negligible. Finally, we concluded that the LinaCheck dosimeter has a good characteristics in terms of dose and setup convenience in daily output measurement. In addition we have shown an examples of clinical use of this dosimeter for measuring daily output more than 60 days.

Accuracy Evaluation of Treatment Planning System Using Irregular-surface Water Phantom / 의학물리

We evaluated on the calculation accuracy of treatment planning system (TPS) with phantom having convex and concave surface. The TPS is Eclipse (Varian, USA) using both algorithms AAA and PBC for photon dose calculations. PBC algorithms have three corrections of Batho, modified Batho (M-Batho), and equivalent TAR (E-TAR). The field sizes were 10x10 cm2 and 20x20 cm2, and MLC-shaped fields for these fields. We measured doses at three depths 5, 10 and 15 cm in phantom of SSD=90 cm in the condition of inserted farmer chamber. For given conditions, we have calculated dose with these algorithms and compared them with measured doses. In AAA the calculated doses (dose/MU) were agreed to measured doses within +/-1% in flat and convex surface and were under estimated with -1.9% maximum in concave surface. In PBC the calculated doses were over estimated with +1.7% and +4.1% respectively in flat and convex surface and the differences were from -3.1% to +2.1% in concave surface. In comparison of criteria from AAPM and IAEA reports, and statistical analysis for these results, it is found that the AAA's results are in good agreement with measured values and the M-Batho's results are generally good agreed with measured values among PBC algorithms.

Determination of Quality Factors for Cylindrical Ionization Chambers in kV X-rays: Review of IAEA Dosimetry Protocol and Monte Carlo Calculations and Measurements for N23333 and N30001 Chambers / 의학물리

The quality factors for cylindrical ionization chambers for kV X-rays were determined by Monte Carlo calculation and measurement. In this study, the X-rays of 60~300 kV beam (ISO-4037) installed in KFDA and specified in energy spectra and beam qualities, and the chambers of PTW N23333 and N30001 were investigated. In calculations, the k(u) and k(Q,Q(0)) in IAEA dosimetry protocols were determined from the air kerma and the cavity dose obtained by theoretical and Monte Carlo calculations. It is shown that the N30001 chamber has a flat response of +/-1.7% in 110~300 kV region, while the response range of two chambers were shown to +/-3~4% in 80~250 kV region. From this work we have discussed dosimetry protocol for the kV X-rays and we have found that the estimation of energy dependency is more important to apply dosimetry protocol for kV X-rays.

Postoperative Radiotherapy in Thymic Carcinoma : A case report

Thymic carcinoma is a rare neoplasm arising in the thymic epithelium. The prognosis of thymic carcinoma is often poor with an aggressive histologic appearance and clinical course. However, few studies about efficacy of treatment modalities have been published because of the rarity of this tumor. Although resection of tumor is the first choice in the treatment of thymic carcinoma, the optimal adjuvant therapy has yet to be defined. A case showed that a patient with thymic carcinoma should be treated by tumor resection followed by radiotherapy alone. And we consider proper management for thymic carcinoma with reviewing literatures

Investigation of Study Items for the Patterns of Care Study in the Radiotherapy of Laryngeal Cancer: Preliminary Results / 대한방사선종양학회지

PURPOSE: In order to develop the national guide-lines for the standardization of radiotherapy we are planning to establish a web-based, on-line data-base system for laryngeal cancer. As a first step this study was performed to accumulate the basic clinical information of laryngeal cancer and to determine the items needed for the data-base system. MATERIALS AND METHODS: We analyzed the clinical data of patients who were treated under the diagnosis of laryngeal cancer from January 1998 through December 1999 in the South-west area of Korea. Eligibility criteria of the patients are as follows: 18 years or older, currently diagnosed with primary epithelial carcinoma of larynx, and no history of previous treatments for another cancers and the other laryngeal diseases. The items were developed and filled out by radiation oncologist who are members of Korean Southwest Radiation Oncology Group. SPSS v10.0 software was used for statistical analysis. RESULTS: Data of forty-five patients were collected. Age distribution of patients ranged from 28 to 88 years (median, 61). Laryngeal cancer occurred predominantly in males (10:1 sex ratio). Twenty-eight patients (62%) had primary cancers in the glottis and 17 (38%) in the supraglottis. Most of them were diagnosed pathologically as squamous cell carcinoma (44/45, 98%). Twenty-four of 28 glottic cancer patients (86%) had AJCC (American Joint Committee on Cancer) stage I/II, but 50% (8/16) had in supraglottic cancer patients (p=0.02). Most patients (89%) had the symptom of hoarseness. Indirect laryngoscopy was done in all patients and direct laryngoscopy was performed in 43 (98%) patients. Twenty-one of 28 (75%) glottic cancer cases and 6 of 17 (35%) supraglottic cancer cases were treated with radiation alone, respectively. The combined treatment of surgery and radiation was used in 5 (18%) glottic and 8 (47%) supraglottic patients. Chemotherapy and radiation was used in 2 (7%) glottic and 3 (18%) supraglottic patients. There was no statistically significant difference in the use of combined modality treatments between glottic and supraglottic cancers (p=0.20). In all patients, 6 MV X-ray was used with conventional fractionation. The fraction size was 2 Gy in 80% of glottic cancer patients compared with 1.8 Gy in 59% of the patients with supraglottic cancers. The mean total dose delivered to primary lesions were 65.98 Gy and 70.15 Gy in glottic and supraglottic patients treated, respectively, with radiation alone. Based on the collected data, 12 modules with 90 items were developed for the study of the patterns of care in laryngeal cancer. CONCLUSION: The study items for laryngeal cancer were developed. In the near future, a web system will be established based on the items investigated, and then a nation-wide analysis on laryngeal cancer will be processed for the standardization and optimization of radiotherapy.

Combined Chemotherapy and Radiotherapy versus Radiotherapy alone in the Management of Localized Angiocentric Lymphoma of the Head and Neck / 대한방사선종양학회지

PURPOSE: To clarify the clinical benefit derived from the combined modality therapy (CMT) consisting of chemotherapy (CT) and involved field radiotherapy (RT) for stage I and II angiocentric lymphomas of the head and neck. MATERIALS AND METHODS: Of 143 patients with angiocentric lymphoma of the head and neck treated at our hospital between 1976 and 1995, 104 patients (RT group) received involved field RT alone with a median dose of 50.4 Gy (range : 20-70 Gy), while 39 patients (CMT group) received a median 3 cycles (range : 1-6 cycles) of CT before involved field RT. The response rate, patterns of failure, complications, and survival data of the RT group were compared with those of the CMT group. RESULTS: Despite a higher response rate, local failure was the most common pattern of failure in patients of both groups. The patterns of failure, including the systemic relapse rate were not influenced by the addition of combination CT. Although both modalities were well tolerated by the majority of patients, aberrant immunologic disorders or medical illnesses, such as a hemophagocytic syndrome, sepsis, intractable hemorrhage, or the evolution of second primary malignancies were more frequently observed in patients of the CMT group. The prognosis of patients in the RT group was relatively poor, with a 5-year overall actuarial survival rate of 38% and disease-free survival rate of 32%, respectively. However, their clinical outcome was not altered by the addition of systemic CT. Achieving complete remission was the most important prognostic factor by univariate and multivariate analyses, but treatment modality was not found to be a prognostic variable influencing survival. Conclusions : Involved field RT alone for angiocentric lymphoma of the head and neck was insufficient to achieve an improved survival rate, but the addition of CT to involved field RT failed to demonstrate any therapeutic advantage over involved field RT alone.

A Study on Apoptotic Signaling Pathway in HL-60 Cells Induced by Radiation / 대한방사선종양학회지

PURPOSE: The mechanical insights of death of cancer cells by ionizing radiation are not yet clearly defined. Recent evidences have demonstrated that radiation therapy may induce cell death via activation of signaling pathway for apoptosis in target cells. This study is designed whether ionizing radiation may activate the signaling cascades of apoptosis including caspase family cysteine proteases, Bcl2/Bax, cytochrome c and Fas/Fas-L in target cells. MATERIALS AND METHODS: HL-60 cells were irradiated in vitro with 6 MV X-ray at dose ranges from 2 Gy to 32 Gy. The cell viability was tested by MTT assay and the extent of apoptosis was determined using agarose gel electrophoresis. The activities of caspase proteases were measured by proteolytic cleavages of substrates. Western blot analysis was used to monitor PARP, Caspase-3, Cytochrome-c, Bcl-2, Bax, Fas and Fas-L. RESULTS: Ionizing radiation decreases the viability of HL-60 cells in a time and dose dependent manner. Ionizing radiation-induced death in HL-60 cells is an apoptotic death which is revealed as characteristic ladder-pattern fragmentation of genomic DNA over 16 Gy at 4 hours. Ionizing radiation induces the activation of caspase-2, 3, 6, 8 and 9 of HL-60 cells in a time-dependent manner. The activation of caspase-3 protease is also evidenced by the digestion of poly (ADP-ribose) polymerase and procaspase- 3 with 16Gy ionizing irradiation. Anti-apoptotic Bcl2 expression is decreased but apoptotic Bax expression is increased with mitochondrial cytochrome c release in a time- dependent manner. In additon, expression of Fas and Fas-L is also increased in a time dependent manner. CONCLUSION: These data suggest that ionizing radiation-induced apoptosis is mediated by the activation of various signaling pathways including caspase family cysteine proteases, Bcl2/Bax, Fas and Fas-L in a time and dose dependent manner.

Radiation-induced Apoptotic Signaling Pathway in HL - 60 Cells / 대한암학회지

PURPOSE: The mechanical insights of death of cancer cells by ionizing radiation are not yet clearly defined. Recent evidences have demonstrated that radiation therapy may induce cell death via activation of signaling pathway for apoptosis in target cells. This study was designed whether ionizing radiation may activate the signaling cascades of apoptosis including caspase family cystein proteases, mitogen-activated protein (MAP) kinases, and transcriptional activation factors in target cells eventually leading to death. MATERIALS AND METHODS: HL-60 cell line in the log phase was used in this study and the culture media was RPMI 1640. The irradiation was done using the linear accelarator and the radiation does was 10 Gy, 20 Gy, and 30 Gy, respectively. The cell viability was tested by MTT assay and apoptosis was identified by the DNA fragmentation assay. JNK1 (cJun N-terminal kinase) and ERK (extracellular-signal regulated protein kinase) activity was analyzed by the in vitro Ig complex kinase assay. NF- kB (Nuclear Factor- kB) and AP-1 (activator protein-1) activity was assayed by the electrophoretic mobility sbift assay. RESULTS: Ionizing radiation decreased the viability of HL-60 cells in a time and dose dependent manner. Ionizing radiation-induced cell death of HL-60 cells may be an apo- ptotic death which was evidenced as apoptotic characteristic ladder pattern fragmentation of DNA over 20 Gy at 4 hours. Ionizing radiation specifically induced the activation of CPP32-like cystein protease rather than ICE-like protease of HL-60 cells in a time and dose dependent manner. The activation of CPP32-like cystein protease was also evidenced by the digestion of poly (ADP-ribose) polymerase with 30 Gy ionizing irradiation at 2 hours. The activity of JNK1 was transiently increased up to 3.6 fold by 30 Gy ionizing radiation at 2 hours. Ionizing radiation also rapidly activated the transcriptional activation factors including AP-1 and NF- kB at 10 or 30 min. CONCLUSION: These data suggested that ionizing radiation-induced apoptosis was mediated by the activation of CPP32-like cystein protease, JNK1, and transcriptional activation factors

Measurement and Monte Carlo Simulation of 6 MV X-rays for Small Radiation Fields / 대한방사선종양학회지

PURPOSE: In order to obtain basic data for treatment plan in radiosurgery, we measured small fields of 6 MV X-rays and compared the measured data with our Monte Carlo simulations for the small fields. MATERIALS AND METHODS: The small fields of 1.0, 2.0 and 3.0 cm in diameter were used in this study. Percentage depth dose (PDD) and beam profiles of those fields were measured and calculated. A small semiconductor detector, water phantoms, and a remote control system were used for the measurement. Monte Carlo simulations were performed using the EGS4 code with the input data prepared for the energy distribution of 6 MV X-rays, beam divergence, circular fields and the geometry of the water phantoms. RESULTS: In the case of PDD values, the calculated values were lower than the measured values for all fields and depths, with the differences being 0.3 to 5.7% at the depths of 2.0 to 20.0 cm and 0.0 to 8.9% at the surface regions. As a result of the analysis of beam profiles for all field sizes at a depth of 10cm in water phantom, the measured 90% dose widths were in good agreement with the calculated values, however, the calculated penumbra radii were 0.1 cm shorter than measured values. CONCLUSION: The measured PDDs and beam profiles agreement with the Monte Carlo calculations approximately. However, it is different when it comes to calculations in the area of phantom surface and penumbra because the Monte Carlo calculations were performed under the simplified geometries. Therefore, we have to study how to include the actual geometries and more precise data for the field area in Monte Carlo calculations. The Monte Carlo calculations will be used as a useful tool for the very complicated conditions in measurement and verification.

Effects of an Opiate Receptor Antagonist Naloxone on Endotoxic Shock and Tumorigenesis / 대한면역학회지

Septic shock is one of the leading cause of death in hospitalized patients and mortality rates of up to 50 % have been reported. Despite all efforts, no regimen today seems to be successful in the treatment of septic shock. The endogenous opioid system (EOS) includes three major families of peptides: dynorphins, endorphins and enkephalins. Several lines of evidence indicate that EOS is implicated in the pathophysiology of anaphylactic and endotoxic shock. An opioid receptor blocker naloxone has been used extensively in studies for the role of EOS or endogenous opiod peptides (EOP). However, there have been few, if any, detailed investigative studies regarding the effect of naloxone on TNF-a production and the lethality in response to endotoxin, and tumorigenesis. ...continue...

Dose Calculation for the Buchler Remote Afterloading System / 대한치료방사선과학회지

PURPOSE: The dose calculation program for the Buchler type remote afterloading system was developed. This program also can be used to calculate dose for various sealed sources. METHODS AND MATERIALS: We determined the source length and distribution by dividing the program disk to 72 points. The dose rate for the each program disk and source was calculated. The dose rate table for the xy coordinate was established. The dose rate for the interesting points of the patient were calculated by using this table. We also made isodose curve from this calculations. RESULTS: The storage size for the dose rate table were increased.But the calculation of the dose rate for the patient were carried out rapidly. So we could get real time calculation. CONCLUSION: By using this program, we could calculate the dose rate for the various oints of the patient quickly and accurately. This program will be useful for the treatment with various linear sources.

Treatment Results and prognostic Factors in Patients with Esophageal Cancer / 대한치료방사선과학회지

PURPOSE: To analyse clinical outcome and prognostic factors according to treatment modality, this paper report our experience of retrospective study of patients with esophageal cancer. MATERIALS AND METHODS: One hundred and ten patients with primary esophageal cancer who were treated in Presbyterian Medical Center from May 1985 to December 1992. We analysed these patients retrospectively with median follow up time of 28 months, one hundred and four patients(95%) were followed up from 15 to 69 months. In methods, twenty-eight patients were treated with median radiation dose irradiated 54.3Gy only. Fifty-six patients were treated with combined chemoradiotherapy. Sixteen cases of these patients were treated with concurrent chemoradiation and the other patients(forty cases) were treated sequential chemoradiotherapy. In concurrent chemoradiotherapy group, patients received 5-FU continuous IV infusion for 4 days. Cisplatin IV bolus, and concurrent esophageal irradiation to 30 Gy. After that patients received 5-Fu continuous IV, Cisplatin bolus injection and Mitomycin-C bolus IV, Bleomycin continuous IV, and irradiation to 20 Gy. In sequential chemoradiotherapy group, the chemotherapy consisted of 5-FU 1,000 mg/m2 administered as a continuous 24 hour intravenous infusion during five days and Cisplatin 80-100 mg/m2 bolus injected, or Bleomycin, Vinblastine, Cisplatin, Methotrexate were used of 1 or 2 cycles. After preoperative concurrent chemoradiation, twenty-six patients underwent radical esophagectomy. RESULTS: ninety-three patients could be examined for response assessment. By treatment modality, response rates were 85.1% for radiation alone group and 86.3% for combined chemoradiation group. But in operation group, after one cycle of concurrent chemoradiation treatment, response rate was 61.9%. Ther pathologic complete response were 15.4% in operation group. Overall median survival was 11 months and actuarial 5-year survival rate was 8%. The median survival interval was 6 months for radiation alone group, 11 months for combined chemoradiation group and 19 months for operation group. And also median survival was 19 months for complete responder group that 8 months for noncomplete responder group. In univariative analysis, statistically significant prognositc factors were tumor size, clinical stage, tumor response, and operation. In multivariative analysis, siginificantly better survival was associated with clinical stage, tumor response, radiation dose, and peration. CONCLUSION: Compared with radiotherapy alone, combined mulimodlity may improve the median survival in patients with localized carcinoma of the esophagus and toxicity is acceptable.