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Tacrolimus is a key drug in kidney transplantation (KT) with a narrow therapeutic index. The association between the tacrolimus metabolism rate and KT outcomes have not been investigated in large-scale multi-center studies. The Korean Organ Transplantation Registry (KOTRY) datasets were used. A total of 3456 KT recipients were analyzed. The tacrolimus metabolism rate was defined as blood trough concentration of tacrolimus (C0 ) divided by the daily dose (D). The patients were grouped into fast, intermediate, or slow metabolizers by the C0 /D measured 6 months after transplantation. The slow metabolism group was associated with a 2.7 ml/min/1.73 m2 higher adjusted estimated glomerular filtration rate (eGFR) at 6 months [95% confidence interval (C.I.) 1.2-4.3, P = 0.001], less acute rejection (AR) within 6 months [Odds ratio (OR) 0.744, 95% C.I. 0.585-0.947, P = 0.016], and less interstitial fibrosis and tubular atrophy [OR 0.606, 95% C.I. 0.390-0.940, P = 0.025]. Fast tacrolimus metabolism affected the 6-month post-KT eGFR through mediation of AR [natural indirect effect (NIE) -0.434, 95% C.I. -0.856 to -0.012, P = 0.044) and delayed graft function (DGF; NIE -0.119, 95% C.I. -0.231 to -0.007, P = 0.038). Slow tacrolimus metabolism was associated with better post-KT eGFR. AR and DGF were found to be significant mediators.

The postoperative hypofractionated intensity-modulated radiation therapy (POHIM-RT) trial is a phase II study to evaluate toxicity following hypofractionated intensity modulated radiation therapy (IMRT) for cervical cancer. This study describes the results of a benchmark procedure for RT quality assurance of the POHIM-RT trial. Six participating institutions were provided computed tomography for RT planning and an IMRT plan for a sample and were instructed to delineate volumes, create a treatment plan and quality assurance (QA) plan, and submit the results of all procedures. The inter-institutional agreements on RT volume and plan results were evaluated using the kappa value and dice similarity coefficients. The simultaneous truth and performance level estimation (STAPLE) method was employed to generate a consensus target volume. The treatment volumes, organs-at-risk volumes, and results of the RT plan and QA reported by the institutions were acceptable and adhered well to the protocol. In terms of clinical target volume (CTV) delineation, there were differences between the institutions, particularly in vaginal cuff and paracolpium subsites. Consensus CTV was generated from the collected CTVs with the STAPLE method. The participating institutions showed considerable agreement regarding volume, dose and QA results. To improve CTV agreement in CTV, we provided feedback with images of the consensus target volume and detailed written guidelines for specific subsites that were the most heterogeneous.

Human immunodeficiency virus (HIV) infection was traditionally considered an absolute contraindication for transplantation because of concerns about HIV disease progression due to immunosuppression. Since potent antiretroviral therapies (ARTs) have become widely available, the prognosis of HIV-infected kidney transplant recipients has dramatically improved. Recent results of prospective multicenter trials on kidney transplantation (KT) in HIV-positive candidates have demonstrated the success and challenges of transplantation in this population. Several studies have reported comparable patient and graft outcomes between HIV-infected and HIV-uninfected recipients after KT in the era of potent combined ARTs. We report two cases of HIV-infected patients who underwent KT at our hospital. In this paper, we present a detailed report of two cases and provide a short review of the existing literature.

Radiation therapy uses high-energy radiation that can cause various side effects depending on the patient's exposure. In particular, side effects occur in the skin due to its radiation exposure to reach the target volume. Therefore, side effects are reduced by clinical trials using various skin dosimeters such as films and glass detectors to determine the dose exposed to the skin. However, accurately measuring the doses using these dosimeters is challenging due to human curvature. In this study, a flexible skin dosimeter was produced using the photoconductor materials mercury oxide (HgO) and lead oxide (PbO). The performance of the proposed dosimeter was evaluated by measuring reproducibility, linearity, dose rate independency according to dose, and percent depth dose (PDD) at photon energy beam. The results showed that the flexible skin dosimeter using HgO material has high applicability as a skin dosimeter due to its stability compared to PbO. The results provide useful insights for the radiation therapy field, particularly in areas where radiation measurement is difficult, depending on the human curvature. The proposed flexible skin dosimeter could serve in various radiation detection areas as a flexible, functional material

Background and Aims Biomarkers associated with chronic kidney disease (CKD) may play a crucial role in patients with diabetic kidney diseases. Vascular endothelial growth factor (VEGF)-C and VEGF-D are lymphangiogenic growth factors. It has been well demonstrated that there is lympnagiogenesis in fibrotic kidney disease in human. Previously, we showed that renal VEGF-C and VEGF-D are involved in lymphangiogensis in renal fibrosis model. Recent studies have shown a relationship between sodium load and serum VEGF-C levels in hypertensive patients. Lymphatic endothelial proliferation has been detected in diabetic nephropathy. Thus, serum VEGF-C level has been introduced as a candidate marker of chronic kidney disease. However, until now, there have been few report about serum VEGF-D in patients with diabetic CKD. Thus, we evaluated the relationships between serum VEGF-D and renal function and albuminuria of diabetic CKD. Method We divided diabetic CKD patients into four groups: CKD stage 3, CKD stage 4, and CKD stage 5 (without dialysis). Total forty two Asian patients with diabetic CKD (14 patients with CKD stage 3, 14 patients with CKD stage 4 and 14 patients with CKD stage 5) and seven healthy controls without diabetes mellitus have been enrolled in this study. In this cross-sectional study, we performed comparative analysis with serum level of VEGF-D in patients with each group. We measured the levels of VEGF-D through the multiplexing using Luminex® technology. Results The serum levels of VEGF-D were higher in the CKD 3, CKD 4 and CKD 5 group compared with the control group (25.9±5.6 pg/ml in control group, 60.3±9.7in stage 3, 62.9±8.5 in stage 4, and 66.5±8.0 in stage 5). However, there was not a significant difference between CKD stage III or IV and CKD stage V in serum levels of VEGF-D. Serum VEGF-D level were negatively correlated with estimated glomerular filtration rate and positively correlated with serum creatinine. At GFR level ≥60 ml/min per 1.73 m2, serum VEGF-D were biomarkers in ROC analysis. There was a positive correlation between serum VEGF-D level and albuminuria in patient with diabetic CKD. We also found that serum VEGF-D level also correlated with urine protein-to-creatinine ratio in patient with diabetic CKD. Conclusion Serum VEGF-D is correlated with renal function in patients with diabetic CKD. VEGF levels in the serum correlate to the severity of proteinuria and albuminuria in diabetic CKD patients. Further large-scale studies are required to confirm these findings.

Brachytherapy is a cancer treatment that involves intensively irradiating a tumor by placing a sealed radioactive isotope inside the body. Determining the position of the source through accurate quality assurance (QA) is important, because brachytherapy uses radioactive isotope sources with high dose rates. However, in clinical practice, the source position is determined with the naked eye through the use of a ruler, autoradiograph, video monitor, etc., which yields inaccurate results. Therefore, in this study, a lead (II) iodide (PbI2) based polycrystalline digital dosimeter that can measure the relative dose was developed for the QA of the brachytherapy device, and its applicability was evaluated in terms of reproducibility, linearity, percentage interval distance (PID), and angular dependence. Reproducibility evaluation yielded a relative standard deviation value of 1.41%, which satisfied the evaluation criterion of 1.5%. The linearity evaluation yielded an R2 value of 0.9993, which satisfied the evaluation criterion of 0.9990. The PID evaluation revealed that, as the distance from the source increased, the signal decreased according to the inverse-square law. When the PbI2-based digital dosimeter was rotated up to 45°, a difference of up to 13.20% in the angular dependence was observed. Thus, the dosimeter fabricated in this experiment met all the criteria of the aforementioned evaluations. Therefore, it is considered to be highly applicable as a dosimeter for the QA of brachytherapy devices.

Cyclosporine A (CsA) is a widely used immunosuppressive agent that may provoke unexpected neurologic complications. The mechanism is unclear and variable intervals have been reported between CsA administration and onset of the related side effects. Here, we describe a case of delayed-onset CsA neurotoxicity presenting as opsoclonus-myoclonus syndrome (OMS).A 37-year-old woman with a two-week period of opsoclonus and upper extremity myoclonus was admitted to our hospital. The patient had been taking CsA for 17 years after receiving a kidney transplant. Further evaluation did not reveal any other abnormalities. Seven days after switching from CsA to tacrolimus, in the absence of additional immune-modulating therapy, her neurologic symptoms improved considerably.This is the case of delayed, long-term complications of CsA presenting as OMS. Symptoms resolved by substituting CsA with another immunomodulating drug. The etiology of the neurologic complications may involve paradoxically-enhanced delayed-type hypersensitivity.

Purpose This study aimed to assess the effects of body mass index (BMI) on survival in cervical cancer patients who had undergone surgery and radiotherapy (RT). Materials and methods We retrospectively reviewed the medical records of 70 cervical cancer patients who underwent surgery and RT from 2007 to 2012. Among them, 40 patients (57.1%) had pelvic lymph node metastases at the time of diagnosis. Sixty-seven patients (95.7%) had received chemotherapy. All patients had undergone surgery and postoperative RT. Median BMI of patients was 22.8 kg/m2 (range, 17.7 to 35.9 kg/m2). Results The median duration of follow-up was 52.3 months (range, 16 to 107 months). Twenty-four patients (34.3%) showed recurrence. Local failure, regional lymph nodal failure, and distant failure occurred in 4 (5.7%), 6 (8.6%), and 17 (24.3%) patients, respectively. The 5-year actuarial pelvic control rate was 83.4%. The 5-year cancer-specific survival (CSS) and disease-free survival (DFS) rates were 85.1% and 65.0%, respectively. The presence of pelvic lymph node metastases (n = 30) and being overweight or obese (n = 34, BMI ≥ 23 kg/m2) were poor prognostic factors for CSS (p = 0.003 and p = 0.045, respectively). Of these, pelvic lymph node metastasis was an independent prognostic factor (p = 0.030) for CSS. Conclusion Overweight or obese cervical cancer patients showed poorer survival outcomes than normal weight or underweight patients. Weight control seems to be important in cervical cancer patients to improve clinical outcomes.

Darbepoetin-alfa is an erythropoiesis-stimulating agent (ESA) with a long elimination half-life that achieves better hemoglobin (Hb) stability than short-acting ESAs. We aimed to evaluate the efficacy and safety of intravenous CKD-11101 (a biosimilar of darbepoetin-alfa) compared with those of darbepoetin-alfa in hemodialysis patients. The study was performed in 24 centers in Korea between June 2015 and June 2017. The study subjects were randomized in a double-blind manner. The follow-up duration was 24 weeks, which consisted of 20 weeks of maintenance and 4 weeks of evaluation period. All patients underwent a stabilization period to achieve a target baseline Hb of 10–12 g/dL before randomization. Following randomization, patients received darbepoetin-alfa or CKD-11101 weekly or biweekly. A total of 403 patients were randomized into two groups, and a total of 325 patients (80.6%) completed the investigation. The differences between the two groups in terms of change in the average Hb level from baseline to evaluation were not significant. The average administered dose of ESA was similar between the groups. There was no difference in the proportion of patients who maintained the target Hb during the evaluation period [60.4% vs. 66.2% in the CKD-11101 and darbepoetin-alfa groups, respectively (p = 0.3038)]. In addition, the safety analysis, consisting of adverse events and adverse drug reactions, showed comparable results between the two groups. The changes in the level of Hb, dose of erythropoietin, and achievement rate of the target Hb during the study period were comparable between the groups. CKD-11101 has an equivalent efficacy and safety compared with darbepoetin-alfa in patients undergoing hemodialysis.

Recent studies revealed that metabolic stress influences the outcomes of breast cancer treatment. We sought to evaluate the prognostic effect of type 2 diabetes and find the molecular mechanism of relapses in postoperative HER-2+ breast cancer patients treated with HER-2 targeted therapy. We evaluated 190 HER-2+ breast cancer patients (pT1-4N0-2M0) who were treated with surgical resection and trastuzumab (HER-2 targeted therapy) between 2006 and 2015. Survival outcomes and failure patterns were compared between such patients with (n = 12) and without (n = 178) type 2 diabetes. The median follow-up period was 42.4 months (range 12.0–124.7 months). Twenty-one patients (11.1%) showed relapse (including nine patients with locoregional failure), and three patients (1.6%) died as a result of cancer relapse. One-third of the patients with diabetes experienced relapse (4/12, 33.3%). The 3-year disease-free survival (DFS) and overall survival (OS) rates were 90.7% and 98.6%, respectively. Diabetic patients showed shorter DFS compared with non-diabetic patients (p = 0.006, 74.1% vs. 91.9%). OS was also shorter in diabetic patients compared with non-diabetic patients (p = 0.017, 91.7% vs. 99.1%). Of our interest, the levels of HER-3 and its ligand neuregulin-1 were significantly increased in the tumor specimen in HER-2+ breast cancer patients suffering with type 2 diabetes than that in the euglycemic control group. Type 2 diabetes was associated with detrimental effects on survival in postoperative HER-2+ breast cancer patients who were treated with trastuzumab. The poor prognostic effect of diabetes in HER-2+ breast cancer patients could be associated with the high levels of HER-3 and neuregulin 1, thus it should be considered and evaluated more.

Purpose This study aimed to identify the feasibility of the maximum standardized uptake value (SUVmax) on baseline 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) as a predictive factor for prognosis in early stage primary lung cancer treated with stereotactic body radiotherapy (SBRT). Materials and methods Twenty-seven T1-3N0M0 primary lung cancer patients treated with curative SBRT between 2010 and 2018 were retrospectively evaluated. Four patients (14.8%) treated with SBRT to address residual tumor after wedge resection and one patient (3.7%) with local recurrence after resection were included. The SUVmax at baseline PET/CT was assessed to determine its relationship with prognosis after SBRT. Patients were divided into two groups based on maximum SUVmax on pre-treatment FDG PET/CT, estimated by receiver operating characteristic curve. Results The median follow-up period was 17.7 months (range, 2.3 to 60.0 months). The actuarial 2-year local control, progressionfree survival (PFS), and overall survival were 80.4%, 66.0%, and 78.2%, respectively. With regard to failure patterns, 5 patients exhibited local failure (in-field failure, 18.5%), 1 (3.7%) experienced regional nodal relapse, and other 2 (7.4%) developed distant failure. SUVmax was significantly correlated with progression (p = 0.08, optimal cut-off point SUVmax > 5.1). PFS was significantly influenced by pretreatment SUVmax (SUVmax > 5.1 vs. SUVmax ≤ 5.1; p = 0.012) and T stage (T1 vs. T2-3; p = 0.012). Conclusion SUVmax at pre-treatment FDG PET/CT demonstrated a predictive value for PFS after SBRT for lung cancer.

Heparin has remained the most commonly used anticoagulant for patients undergoing hemodialysis. It is usually safe to use but can have severe adverse effects in some cases. Heparin-induced thrombocytopenia (HIT) is a life-threatening complication of exposure to heparin. It results from an autoantibody directed against endogenous platelet factor 4 (PF4) in complex with heparin, which activates platelets and can cause catastrophic arterial and venous thromboses. Here, we present the case of an 80-year-old woman with a recent diagnosis of chronic renal failure who developed acute HIT (platelet count nadir, 15 × 109 /L) on day 7 of hemodialysis performed with routine heparin anticoagulation, who despite subsequent heparin-free hemodialysis (with argatroban and warfarin) developed recurrent HIT (complicated by acute cerebral infarction) on day 11 that we attributed to "rinsing" of the circuit with heparin-containing saline (3,000 units of unfractionated heparin, with subsequent saline washing) performed pre-dialysis as per routine. After stopping heparin rinsing, the platelet count recovered completely, without further thrombotic or other sequelae. Our experience indicates that for patients with acute HIT, besides the well-known practice of using non-heparin anticoagulation during dialysis and avoiding heparin "locking" of dialysis catheters, it is also important to avoid inadvertent rinsing of the circuit with heparin during preparation for hemodialysis.

Because systems that reduce radiation exposure during diagnostic procedures must be developed, significant time and financial resources have been invested in constructing radiation dose management systems. In the present study, the characteristics of an existing ionization-based system were compared to those of a system based on the kinetic energy released per unit mass (KERMA). Furthermore, the feasibility of using the KERMA-based system for patient radiation dose management was verified. The ionization-based system corrected the effects resulting from radiation parameter perturbations in general radiography whereas the KERMA-based system did not. Because of this difference, the KERMA-based radiation dose management system might overestimate the patient’s radiation dose due to changes in the radiation conditions. Therefore, if a correction factor describing the correlation between the systems is applied to resolve this issue, then a radiation dose management system can be developed that will enable real-time measurement of the patient’s radiation exposure and acquisition of diagnostic images.

Purpose The association between metabolism and cancer has been recently emphasized. This study aimed to find the prognostic significance of obesity in advanced stage rectal cancer patients treated with surgery and radiotherapy (RT). Materials and methods We retrospectively reviewed the medical records of 111 patients who were treated with combined surgery and RT for clinical stage 2-3 (T3 or N+) rectal cancer between 2008 and 2014. The prognostic significance of obesity (body mass index [BMI] ≥25 kg/m(2)) in local control was evaluated. Results The median follow-up was 31.2 months (range, 4.1 to 85.7 months). Twenty-five patients (22.5%) were classified as obese. Treatment failure occurred in 33 patients (29.7%), including local failures in 13 patients (11.7%), regional lymph node failures in 5, and distant metastases in 24. The 3-year local control, recurrence-free survival, and overall survival rates were 88.7%, 73.6%, and 87.7%, respectively. Obesity (n = 25) significantly reduced the local control rate (p = 0.045; 3-year local control, 76.2%), especially in women (n = 37, p = 0.021). Segregation of local control was best achieved by BMI of 25.6 kg/m(2) as a cutoff value. Conclusion Obese rectal cancer patients showed poor local control after combined surgery and RT. More effective local treatment strategies for obese patients are warranted.

// Eun-Tae Park 1 , Sung Kwang Park 1 1 Department of Radiation Oncology, Busan Paik Hospital, Inje University School of Medicine, Busan, Korea Correspondence to: Sung Kwang Park, email: physicist@paik.ac.kr Keywords: head and neck cancer, setup error, cervical spine, organ motion Received: March 07, 2016 Accepted: April 27, 2016 Published: May 31, 2016 ABSTRACT Purpose: The aim of this study is to determine the inter-fractional motion of cervical spine in radiotherapy (RT). Materials and Methods: Eleven localized head and neck cancer patients who were treated from April 2014 to September 2015 were evaluated. Every patient underwent 3 times of computed tomography (CT) simulation with equivalent setting. Left-right (LR, x) and antero-posterior (AP, z) directional shift of cervical spine were evaluated using 33 number of CT image. In regard to random error, geometric changes were evaluated by 22 data set (compared the first obtained CT to second or third CT) by one-sample T test. Systemic error was evaluated by each patients’ data set (11 pairs) by paired T test. Results: The mean random error of LR and AP translational shift of cervical spine were −0.39 ± 3.24 mm and −0.57 ± 0.99 mm respectively. The mean random error of translational change of AP direction showed statistical significance ( p = 0.014). The mean random error of x and z rotational shift were −0.07 ± 0.29° and −0.05 ± 0.35°, respectively. The mean systemic error of translational shift of LR and AP direction were −0.64 ± 2.57 mm and −0.33 ± 1.22 mm, respectively. The mean systemic error of rotational shift of x and z were 0.01 ± 0.18° and −0.27 ± 0.33°, respectively. The mean systemic error of rotational changes of z direction showed statistical difference ( p = 0.022). Conclusions: We have to be aware of the inter-fractional motion of cervical spine in head and neck RT and give enough margins in RT planning.

Purpose This study aimed to evaluate the effects of radiotherapy (RT) on progression-free survival (PFS) for patients with recurrent colorectal cancer. Methods We reviewed the records of 22 patients with recurrent colorectal cancer treated with RT between 2008 and 2014. The median radiation dose for recurrent disease was 57.6 Gy (range, 45–75.6 Gy). Patients were divided into 2 groups according to the type of RT: patients underwent RT without previous history of irradiation (n = 14) and those treated with secondary RT (reirradiation: n = 8) at the time of recurrence. Results The median follow-up period was 24.9 months (range, 4.5–66.6 months). Progression was observed in 14 patients (including 8 with loco-regional failure and 9 with distant metastases). Distant metastases were related to the RT dose (

Radiation treatment requires high accuracy to protect healthy organs and destroy the tumor. However, tumors located near the diaphragm constantly move during treatment. Respiration-gated radiotherapy has significant potential for the improvement of the irradiation of tumor sites affected by respiratory motion, such as lung and liver tumors. To measure and minimize the effects of respiratory motion, a realistic deformable phantom is required for use as a gold standard. The purpose of this study was to develop and study the characteristics of a deformable moving lung (DML) phantom, such as simulation, tissue equivalence, and rate of deformation. The rate of change of the lung volume, target deformation, and respiratory signals were measured in this study; they were accurately measured using a realistic deformable phantom. The measured volume difference was 31%, which closely corresponds to the average difference in human respiration, and the target movement was - 30 to + 32mm. The measured signals accurately described human respiratory signals. This DML phantom would be useful for the estimation of deformable image registration and in respiration-gated radiotherapy. This study shows that the developed DML phantom can exactly simulate the patient׳s respiratory signal and it acts as a deformable 4-dimensional simulation of a patient׳s lung with sufficient volume change.

Yes-associated protein (YAP) activation after acute ischemic kidney injury might be related to interstitial fibrosis and impaired renal tubular regeneration. Verteporfin (VP) is a photosensitizer used in photodynamic therapy to treat age-related macular degeneration. In cancer cells, VP inhibits TEA domain family member (TEAD)-YAP interactions without light stimulation. The protective role of VP in unilateral ureteral obstruction (UUO)-induced renal fibrosis and related mechanisms remains unclear. In this study, we investigate the protective effects of VP on UUO-induced renal tubulointerstitial inflammation and fibrosis and its regulation of the transforming growth factor-&beta, 1 (TGF-&beta, 1)/Smad signaling pathway. We find that VP decreased the UUO-induced increase in tubular injury, inflammation, and extracellular matrix deposition in mice. VP also decreased myofibroblast activation and proliferation in UUO kidneys and NRK-49F cells by modulating Smad2 and Smad3 phosphorylation. Therefore, YAP inhibition might have beneficial effects on UUO-induced tubulointerstitial inflammation and fibrosis by regulating the TGF-&beta, 1/Smad signaling pathway.

Digital tomosynthesis (DTS) is a geometric tomography technique using a limited-angle scan. It has been popularly used in both medical and industrial x-ray imaging applications. DTS provides the tomographic benefits of computed tomography with reduced dose and time. However, conventional DTS reconstruction based on the computationally cheap filtered back-projection (FBP) method typically produces poor image quality due to limited angular samplings. To overcome these difficulties, iterative reconstruction methods are often used in DTS reconstruction as they have the potential to provide multiplanar images of higher quality than conventional FBP-based methods. However, they require enormous computational cost in the iterative process, which remains an obstacle to practical applications. In this study, we propose a method for effectively reducing limited-angle artifacts in conventional FBP reconstruction, using a state-of-the-art deep learning scheme with a convolutional neural network. Our results indicate that the proposed DTS reconstruction method effectively minimized limited-angle artifacts, thus improving image performance in DTS, and that further it provided good image quality in both sagittal and coronal views (as in computed tomography) as well as in axial view.

Posttransplant erythrocytosis (PTE) is a common complication of renal transplantation, which can occur in approximately 10% to 15% of renal transplant patients and usually affects males with relatively good renal function. It is also associated with an increased incidence of thromboembolic events. Clinical manifestations of PTE include malaise, headache, plethora, lethargy, and dizziness. It is correlated with use of cyclosporin, gender, posttransplant renal function, and type of antihypertensive medication. The angio- tensin receptor blocker (ARB) or angiotensin-converting enzyme inhibitor is preferred as an initial treatment for PTE because these agents are effective and reasonably safe in the majority of patients with PTE, and can also provide a necessary antihypertensive effect for kidney transplant patients. We report here on a 35-year-old male who had erythrocytosis after renal transplantation. After renal transplantation, his level of hemoglobin was 21 g/dL. We treated this patient with ARB and his symptoms and signs have been completely relieved.

Currently, the American Association of Physicists in Medicine (AAPM) recommends measuring the surface field size once a week by using an analog film in order to verify light and radiation field coincidence in the Quality Assurance (QA) of radiotherapy. However, the use of the film does not allow for a quantitative method of evaluation, and measuring the light field with radiation field detectors in a 2D array is difficult. Therefore, we used an amorphous-Se (a-Se) digital radiation detection system to measure the light and radiation fields simultaneously for a quantitative QA system, and the feasibility of using such a system was confirmed by ensuring the coincidence of the light and the radiation field measurements. The characteristics of the analog film and the a-Se digital radiation detection system were compared by delivering to each doses of 100, 10 monitor units(MU) of radiation at a rate of 400 MU/min to a radiation field 100 × 100 mm2 in size from a 100 cm source-surface distance (SSD). A 0.5 mm to 0.6 mm difference was measured in the X-axis, and a 0.3 mm difference was measured in the Y-axis. The difference in the measurements of the coincidence of light and the radiation field was less than 0.3 mm, which is relatively insignificant. These results indicate that the use of an a-Se digital radiation detection system is adequate for quality assurance of radiotherapy using light and radiation field coincidence. In addition, the experiment is considered to have provided valuable results in that the a-Se based digital radiation detection system enables simple and accurate QA for clinical radiation therapy by assessing the coincidence in the alignment of the light and the radiation fields.

Intensity-modulated radiotherapy (IMRT) improves dose conformity and saves critical organs. IMRT is widely used in cases of head and neck, prostate, and brain cancer due to the close location of the targets to critical structures. However, because IMRT has a larger amount of radiation exposure than 3 dimensional-conformal radiation therapy (3D-CRT), it has disadvantages such as increases in the low dose irradiation to normal tissues and in the accumulated dose for the whole volume due to leakage and transmission of the multi-leaf collimator (MLC). The increased accumulated dose and the larger low dose may increase the occurrence of secondary malignant neoplasms. For these reasons, the jaw-tracking function of the TrueBeam (Varian Medical Systems, Palo Alto, CA) was developed to reduce the leakage and the transmission dose of the MLC with linear accelerators. However, the change in the superficial dose has not been verified with a quantitative analysis of the dose reduction in a brain tumor. Therefore, in the present study, we intended to verify the clinical possibility of utilizing the jaw-tracking function for a brain tumor by comparing treatment plans and superficial doses. To accomplish this, we made three types of original treatment plans using Eclipse11 (Varian Medical Systems, Palo Alto, CA): 1) farther than 2 cm from the organs at risk (OAR); 2) within 2 cm of the OAR; and 3) intersecting with the OAR. Jaw-tracking treatment plans were also made with copies of the original treatment plan using Smart LMC Version 11.0.31 (Varian Medical Systems, Palo Alto, CA). A comparison between the original treatment plans and jaw-tracking treatment plans was performed using the difference of the mean dose and maximum dose to the OARs in cumulative Dose Volume Histogram (DVH). In addition, the dependencies of the effects of transmission and the scattering doses according to jaw motion were assessed through the difference in the surface doses. In the DVH comparison, a maximum dose difference of 0.4% was observed between the planning methods in the case of over 2 cm distance, and the maximum dose of 0.6% was obtained for within the 2 cm distance. For the case intersecting with the OAR, the maximum dose difference of 2.3% was achieved. According to these results, the differences in the mean doses and the maximum doses to the OARs ware larger when the OARs and the planning target volume (PTV) were closer. In addition, small differences in the surface dose measurements were observed. In the case of the inside field, the differences were under 2% of the prescription dose while the difference was under 0.1% in the case of the outside field. Therefore, treatment plans with the jaw-tracking function consistently affected the dose reduction for a brain tumor, and the clinical possibility could be verified as the surface dose was not increased.

In-vivo dosimetry is essential to verify the position and the intensity of the radiation therapy, such as cranio-spinal irradiation (CSI) and total body irradiation (TBI). Various kinds of devices, such as a thermo-luminesence dosimeters (TLDs), metal-oxide semiconductor field effect transistors (MOSFETs), semiconductor diodes, and gafchromic films, are used in in-vivo dosimetry, and these have their respective pros and cons. An optically-stimulated luminescent nanodot dosimeter (OSLnD) made of Al2O3: C was developed to measure the radiation dose during diagnostics, but it is now used for clinical purposes. In this study, the characteristics of the OSLnD, such as its dose rate dependency, dose linearity, angular dependency, and field junction, were investigated under a 6 MV X-ray beam. The OSLnD showed a linear response at doses from 20 to 300 cGy in the dose linearity test. Also, the dose rate dependency was shown to be less than 3%, angular dependency to be less than 2%. The experimental results proved the OSLnD to be useful for measurements of the external dose and for intensity modulated radiotherapy (IMRT) in clinical radiotherapy.

Purpose The purpose of this study was to determine the optimal biologically equivalent dose (BED) for stereotactic body radiotherapy (SBRT) by comparing local control rates in proportion to various total doses and fractionation schedules. Materials and Methods Thirty-four patients with early non-small-cell lung cancer and a single metastatic lung tumor were included in this study. Differences in local control rates were evaluated according to gender, primary tumor site, response, tumor size, and BED. For comparison of BEDs, the prescribed dose for SBRT was stratified according to three groups: high (BED > 146 Gy), medium to high (BED, 106 to 146 Gy), and low to medium (BED < 106 Gy). Results For all patients, the overall local control rate was 85.3% at two years after treatment. Five local recurrences were observed, and, notably, all of them were observed in the low to medium BED group. Significantly higher local control rates were observed for patients with a complete response than for those with a partial response or stable disease (p < 0.001). Twenty-six patients with a tumor size of < 3 cm showed no dose-response relationship in the low to medium, medium to high, and high BED groups, whereas eight patients with a tumor size of ≥ 3 cm showed a significant dose-response relationship. The observed 2-year local recurrence-free survival rates in patients with a tumor size of < 3 cm and in those with a tumor size of ≥ 3 cm were 96.2% and 50.0%, respectively, which were significantly different (p=0.007). Conclusion BED > 100 Gy is required in order to achieve a > 85% local control rate regardless of tumor size. The optimal dose for small tumors of < 3 cm appears to be within a range below 150 Gy BED. Escalation of BED to high levels (> 150 Gy) may be required for patients with a tumor size larger than 3 cm.

The number of people awaiting organ transplantation continues to exceed the number of organs available for transplantation, especially at a time when kidney transplantation is recognized as the best treatment option for end stage renal disease. There may be many reasons for this disparity of organ supply and demand, including the lack of consent, absence of an experienced coordinator team to help in closing the widening gap between organ supply and demand, and an unstandardized critical care management of potential organ donors. According to the report of the Korean Organ Transplant Registry in March 2014, due to a serious organ shortage in Korea, kidneys of deceased donors with low initial estimated glomerular filtration rate of

To improve the image quality in cone-beam computerized tomography, a detector containing an insulator layer made of parylene-C was utilized in this study. In HgI2 sensors with photoconducting materials, we analyzed the signal based on the thickness of the parylene-C layer and leakage current. In addition, we tried to evaluate the reproducibility of Hgl2 that decreases gradually based on the continuous X-ray study. For the signal-to-noise ratio, we evaluated the photocurrent/darkcurrent (P/D) ratio according to the reduction in the leakage current. Our results indicated a detector reproducibility of 0.82% for a parylene-layer thickness of 18 μm, which represents an improvement of 0.43% over that of a "parylene-free" detector. Compared with the parylene-free sensors, the ones with a parylene layer displayed an approximately linear increase of the P/D ratio with increasing parylene layer thickness. For layers 18 or 20 μm thick this ratio, indicative of image quality, exhibited an improvement of ~ 70 times or more in comparison to a parylene-free sensor.

This study investigated analytic digital tomosynthesis (DTS) reconstruction in partial sampling with a multislit collimator that partially blocks the x-ray beam to the patient during projection data acquisition, thereby reducing excessive radiation dose to patients. Partially-sampled DTS images reconstructed using the analytic filtered-backprojection (FBP) algorithm usually suffer from severe bright-band artifacts around multislit edges of the collimator due to incomplete spatial sampling. In this study, a new prior sinogram interpolation method was introduced to the analytic DTS reconstruction in partial sampling to alleviate such artifacts. To verify the proposed DTS method, we conducted a systematic simulation and investigated image characteristics. Three multislit collimator layouts of C(2/2), C(3/3), and C(4/4) with a 50% duty cycle were designed and used in the simulation. Here C(n/n) denotes a collimator layout that blocks the x-ray beam over n detector pixels vertically with a n-pixel interval. All projections were obtained at a tomographic angle of θ = ±40o and an angle step of Δθ = 2o and used to reconstruct DTS images using the FBP algorithm. Our results indicate that the proposed sinogram interpolation method effectively minimized bright-band artifacts in analytic DTS reconstruction in partial sampling, thus maintaining the image quality.

Ui Jun Park, M.D., Won Hyun Cho, M.D., Hyoung Tae Kim, M.D., Min Young Kim, R.N., Yong-Lim Kim, M.D., Chan-Duck Kim, M.D., Jang-Hee Cho, M.D., Young Hoon Kim, M.D., Suk Joo Park, M.D., Sang Young Chung, M.D., Soo Jin Na Choi, M.D., Ho Kyun Lee, M.D., Sung Kwang Park, M.D., Sik Lee, M.D. and Hee Chul Yu, M.D. Department of Surgery, Keimyung University Dongsan Medical Center, Keimyung University School of Medicine, Department of Internal Medicine, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Department of Internal Medicine, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Department of Surgery, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Department of Internal Medicine, Surgery, Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Korea

Background: Interstitial tonicity increases vascular endothelial growth factor-C (VEGF-C), a lymphangiogenic factor in salt-induced hypertension. Therefore, it can be assumed that changes of serum VEGF-C level may be associated with increasing blood pressure. However, there is no report about the changes of serum VEGF-C levels in patients with chronic kidney disease (CKD). The aims of this study were to investigate the changes of serum and urine VEGF-C levels in patients with CKD stage 3–4 and to evaluate the relationship between blood pressure and serum VEGF-C levels in the patients with CKD stage 5 and hemodialysis. Methods: Glomerular filtration rate (GFR) was assessed by the Modification of Diet in Renal Disease equation. Blood pressure and VEGF-C levels (serum and urine) were measured by enzyme-linked immunosorbent assay (ELISA) in nine patients with stage 3–4 CKD, 41 hemodialysis patients, and eight healthy individuals. Results: The median serum level of VEGF-C in patients with stage 3–4 CKD and stage 5 hemodialysis significantly decreased in comparison with healthy individuals. Urinary VEGF-C excretion increased in patients with stage 3–4 CKD compared with healthy control patients. For 41 hemodialysis patients, the serum level of VEGF-C in patients with stage 1 or stage 2 hypertension with hemodialysis did not significantly increase when compared with prehypertension hemodialysis patients. Conclusion: We demonstrated that circulating levels of VEGF-C were decreased in patients with CKD, and the decrease of VEGF-C in patients with stage 3–4 CKD coincided with an increase in the urinary excretion of VEGF-C.

Medical radiation imaging systems employ phosphors such as CaWO4 as X-ray receptor materials. Unfortunately, the conversion efficiencies of these materials are rather low (approx. 5%). Alternatives that comprise a bulk structure have been fabricated from rare earth metals, but they are not efficient enough to produce high quality images. Nano-phosphors do not suffer from the limitations inherent to the bulk structures of conventional phosphors. We examined the effects of sensitizer doping conditions on the optical characteristics and morphology of the rare earth phosphor Gd2O3:Eu to fabricate a novel type of nano-phosphor. We optimized a temperature solution-combustion procedure for producing phosphors doped with 5 wt% Eu. Scanning electron microscopy images showed that the phosphors were 20-30 nm in diameter and X-ray diffraction analysis revealed that they underwent polycrystalline growth upon the addition of a sensitizer, similar to the polycrystalline growth of bulk phosphors. In addition, the phosphors exhibited a strong peak at 613 nm and luminescence similar to conventional phosphors. Phosphors that were produced using citric acid as a sensitizer showed more than double the level of luminescence and could be used to produce higher quality images compared to non-sensitized phosphors. The phosphors also exhibited a high degree of luminescence stability.

Objective:We report two extremely rare cases of symptomatic nasopharyngeal branchial cleft cyst treated by powered instrument assisted marsupialisation.Methods:Case report and literature review concerning nasopharyngeal branchial cleft cyst and surgical treatment methods.Results:The first case was a two-year-old boy with a 1 × 2 cm, cystic, oropharyngeal mass, who also had severe snoring and sleep apnoea. The second case was a 56-year-old man with right nasal obstruction and a sensation of fullness in the right ear. In both cases, we performed endoscopic marsupialisation using a powered instrument. There was no recurrence in either case over two years of follow up.Conclusion:Powered instrument marsupialisation is a simple, effective and less invasive technique for the treatment of nasopharyngeal branchial cleft cyst.

As the number of cancer patients and its death rate increases, this study is to understand the occurrences in cancer patients in Busan area and to provide active help for treatment, prevention and management of cancer patients. It was investigated and analyzed based on 4462 patients who were diagnosed with cancer and received radiation therapy from Jan. 2011 to Dec. 2012 at tertiary medical institution in Busan area. The seven main cancer types were breast cancer, cervical cancer, lung cancer, colon rectal cancer, brain tumor, laryngopharyngeal cancer and liver cancer. The most common type of cancer was breast cancer which takes up 38.1% of cancer patients stood out from other cancer types. Breast cancer is that shows increasing trend and in need of appropriate countermeasures and managements for decreasing cancer risk. Therefore the causes and prevention of breast cancer analysis, an appropriate management program is required.

The use of the dosimetry have been increasingly recognized as high radiation energy and radiation treatment planning(RTP) have rapidly developed in radiotherapy. There are many types of detectors for the dosimetry such as ionization chamber, film, TLD, diode, and etc. Among such detectors, the diode detector uses a photoconductor materials that generate electrical signals by the incident radiation energy. Though many research groups are recently interested in such materials, there is few experimental results except for silicon in the radiation therapy field. In this study, the feasibility of photoconductor materials was verified as a dosimeter through the evaluation of response properties at a high radiation energy. For the fabricated detectors based on HgI2 and PbI2, reproducibility, linearity, and pulse-rate response were analyzed. Such evaluations are essential factors for the use of dosimeter. From results, linearity and reproducibility of the fabricated HgI2 detector indicated about 7% error. The fabricated PbI2 detector showed 1.7% error in linearity, and 12.2% error in reproducibility.

Whole blood viscosity (WBV) plays a role in hemorheology and is determined by many factors such as red blood cell factors, plasma protein and blood volume. As WBV changes during hemodialysis, mortality may be due to changes in WBV in patients on hemodialysis. However, there are few prospective data on the relationship between changes in WBV and overall mortality in dialysis patients. We tried to investigate the correlations between values of WBV at variable shear rates before and after hemodialysis and overall or atherosclerosis-related mortality in patients with end-stage kidney disease.Forty-three patients receiving hemodialysis were enrolled in this study. In this 5.8-year prospective observational study, analyses of the effects of WBV at shear rates of 300 s-1 (systolic WBV; SBV), 5 s-1 (diastolic WBV5; DBV5), and 1 s-1 (diastolic WBV1; DBV1) during dialysis on all-cause and atherosclerotic mortality was performed.Among a total of 43 patients, 27 (62.7%) died over the course of the study. Thirteen deaths were caused by atherosclerotic events. A high degree of change in WBV at shear rates of 300 s-1 and 5 s-1 during hemodialysis (ΔSBV, ΔDBV5) was positively correlated with overall mortality (HR = 4.688, 95% confidence interval [CI], 1.269-17.319, p = 0.020; HR = 3.941, 95% CI, 1.057-14.701, p = 0.041, respectively). A high degree of change in diastolic blood pressure (ΔDBP) during hemodialysis was also positively correlated with overall mortality (HR = 3.035, 95% CI, 1.039-8.867, p = 0.042). However, comparative analysis between WBV at shear rates of 300 s-1, 5 s-1, and 1 s-1 and overall mortality did not reveal any significant relationships. Kaplan-Meier analysis revealed that the all-cause mortality was significantly higher in patients from a high degree of change of WBV at shear rates of 300 s-1, compared to those from the moderate or low degree of changes of WBV at shear rates of 300 s-1 (p = 0.020, log-rank test). Survival rate in high ΔDBP was lower than that of moderate or low ΔDBP group in Kaplan-Meier survival analysis (p = 0.004, log-rank test).Our data showed that a high degree of change in WBV at variable shear rates during hemodialysis might impact overall survival in patients with end-stage kidney disease. However, large-scale studies to evaluate the relationship of WBV with overall mortality and atherosclerotic mortality will be needed.

Hypertensive nephrosclerosis is usually associated with chronic hypertension, which increases the risk of progressive renal disease. Among the causes of malignant hypertension, thrombotic microangiopathy is complicated and is associated with renal dysfunction at the time of diagnosis. In this case, a young man with hypertension presented with renal failure and thrombocytopenia in the emergency department. This case emphasizes the importance of early recognition of renal failure and thrombocytopenia among patients with uncontrolled hypertension.