Development of shielding evaluation and management program for O-ring type linear accelerators.

The shielding parameters can vary depending on the geometrical structure of the linear accelerators (LINAC), treatment techniques, and beam energies. Recently, the introduction of O-ring type linear accelerators is increasing. The objective of this study is to evaluate the shielding parameters of new type of linac using a dedicated program developed by us named ORSE (O-ring type Radiation therapy equipment Shielding Evaluation). The shielding evaluation was conducted for a total of four treatment rooms including Elekta Unity, Varian Halcyon, and Accuray Tomotherapy. The developed program possesses the capability to calculate transmitted dose, maximum treatable patient capacity, and shielding wall thickness based on patient data. The doses were measured for five days using glass dosimeters to compare with the results of program. The IMRT factors and use factors obtained from patient data showed differences of up to 65.0% and 33.8%, respectively, compared to safety management report. The shielding evaluation conducted in each treatment room showed that the transmitted dose at every location was below 1% of the dose limit. The results of program and measurements showed a maximum difference of 0.003 mSv/week in transmitted dose. The ORSE program allows for the shielding evaluation results to the clinical environment of each institution based on patient data.

Assessment of radio-activation using spectroscopy in medical linear accelerators.

In radiotherapy, when photon energy exceeding 8 MV is utilized, photoneutrons can activate the components within the gantry of the linear accelerator (linac). At the end of the linac's lifecycle, radiation workers are tasked with its dismantling and disposal, potentially exposing them to unintentional radiation. This study aims to identify and measure the radioisotopes generated by this activation through spectroscopy, and to evaluate the effective dose rate. We selected nine medical linacs, considering various factors such as manufacturer (Siemens, Varian, and Elekta), model, energy, period of operation, and workload. We identified the radionuclides in the linac head by employing an in situ high-purity germanium (HPGe) detector. Spectroscopy and dose-rate measurements were conducted post-shutdown. We also measured the dose rates at the beam-exit window following irradiation with 10 MV and 15 MV photon beams. As a result of the spectroscopy, we identified approximately 20 nuclides including those with half-lives of 100 days or longer, such as 54Mn, 60Co, 65Zn, 122Sb, and 198Au. The dose rate measurements after 10 MV irradiation decreased to the background level in 10 min. By contrast, on 15 MV irradiation, the dose rate was 628 nSv/h after 10 min and decreased to 268 nSv/h after 1.5 hours. It was confirmed that the difference in the level of radiation and the type of nuclide depends on the period of use, energy, and workload. However, the type of nuclide does not differ significantly between the linacs. It is necessary to propose appropriate guidelines for the safety of workers, and disposal/move-install should be planned while taking into consideration the equipment's energy usage rate.

Comparison of skin dose in IMRT and VMAT with TrueBeam and Halcyon linear accelerator for whole breast irradiation.

With the increasing use of flattening filter free (FFF) beams, it is important to evaluate the impact on the skin dose and target coverage of breast cancer treatments. This study aimed to compare skin doses of treatments using FFF and flattening filter (FF) beams for breast cancer. The study established treatment plans for left breast of an anthropomorphic phantom using Halcyon's 6-MV FFF beam and TrueBeam's 6-MV FF beam. Volumetric modulated arc therapy (VMAT) with varying numbers of arcs and intensity modulated radiation therapy (IMRT) were employed, and skin doses were measured at five points using Gafchromic EBT3 film. Each measurement was repeated three times, and averaged to reduce uncertainty. All plans were compared in terms of plan quality to ensure homogeneous target coverage. The study found that when using VMAT with two, four, and six arcs, in-field doses were 19%, 15%, and 6% higher, respectively, when using Halcyon compared to TrueBeam. Additionally, when using two arcs for VMAT, in-field doses were 10% and 15% higher compared to four and six arcs when using Halcyon. Finally, in-field dose from Halcyon using IMRT was about 1% higher than when using TrueBeam. Our research confirmed that when treating breast cancer with FFF beams, skin dose is higher than with traditional FF beams. Moreover, number of arcs used in VMAT treatment with FFF beams affects skin dose to the patient. To maintain a skin dose similar to that of FF beams when using Halcyon, it may be worth considering increasing the number of arcs.

Development of open access tool for automatic use factor calculation using DICOM-RT patient data.

Our study recalculated the use factor of linear accelerators (LINACs) by using an in-house program based on Digital Imaging and Communications in Medicine radiation therapy (DICOM-RT). We considered the impact of advancements and changes in treatment trends, including modality, technology, and radiation dose, on the use factor, which is one of the shielding parameters. In accordance with the methodology described in the NCRP 151 report, we computed the use factor for four linear accelerators (LINACs) across three hospitals. We analyzed the results based on the treatment techniques and treatment sites for three-dimensional conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy or volumetric modulated arc therapy. Our findings revealed that the use factors obtained at 45° and 90° were 14.8% and 13.5% higher than those of the NCRP 151 report. In treatment rooms with a high 3D-CRT ratio, the use factor at a specific angle differed by up to 14.6% relative to the NCRP 151 report value. Our results showed a large difference in the use factor for specific sites such as the breast and spine, so it is recommended that each institution recalculate the use factor using patient's data.

Clinical Application of a Customized 3D-Printed Bolus in Radiation Therapy for Distal Extremities.

In radiation therapy (RT) for skin cancer, tissue-equivalent substances called boluses are widely used to ensure the delivery of an adequate dose to the skin surface and to provide a radioprotective effect for normal tissue. The aim of this study was to develop a new type of three-dimensional (3D) bolus for RT involving body parts with irregular geometries and to evaluate its clinical feasibility. Two 3D-printed boluses were designed for two patients with squamous cell carcinoma (SCC) of their distal extremities based on computed tomography (CT) images and printed with polylactic acid (PLA). The clinical feasibility of the boluses was evaluated by measuring the in vivo skin dose at the tumor site with optically stimulated luminescence detectors (OSLDs) and comparing the results with the prescribed and calculated doses from the Eclipse treatment planning system (TPS). The average measured dose distribution for the two patients was 94.75% of the prescribed dose and 98.8% of the calculated dose. In addition, the average measured dose during repeated treatments was 189.5 ± 3.7 cGy, thus demonstrating the excellent reproducibility of the proposed approach. Overall, the customized 3D-printed boluses for the RT of distal extremities accurately delivered doses to skin tumors with improved reproducibility.

Development of Total Lymphoid Irradiation (TLI)-Dedicated Shielding and Image-Guided System and Dose Evaluation Using 3D-Printed Rat Phantom.

Purpose: The purpose of this study is to propose a technique for delivering accurate doses in an image-guided system by developing an experimental setup optimized for total lymphoid irradiation (TLI) in rat lung transplantation. Materials and Methods: In this study, a position-controlled shielding system was developed, and the dose was quantitatively evaluated using a 3D rat phantom and Gafchromic EBT3 film. In addition, we made our own image-guided system that allows the position of the rat and the shielding system to be confirmed during TLI. Results: As a result of using the position-controlled shielding system, it was found that the doses to the head and lungs were reduced by 93.1 and 87.4%, respectively, of the prescribed doses. In addition, it was shown that the position of the shielding system can be easily confirmed by using the image guidance system. Conclusion: A shielding apparatus that can control dose delivery according to the size of the rat can optimize the dose for TLI in rat lung transplantation.

Associations of health-related quality of life with depression and stigma in MERS-CoV survivors during the recovery period.

ABSTRACT: We explored factors related to health-related quality of life (HRQOL), including psychiatric symptoms and stigma related to Middle East respiratory syndrome coronavirus (MERS-CoV) infection, among MERS-CoV survivors during the recovery period.Sixty-three MERS-COV survivors were recruited from five hospitals for a cohort study, one year after their infection in 2015. The subjects' demographic information and medical conditions associated with MERS-CoV were recorded. HRQOL was evaluated using the Short Form-8 Health Survey (SF-8). Depression, post-traumatic stress symptoms, chronic fatigue, and perceived stigma were assessed using several questionnairesThe mean physical component summary (PCS) and mean mental component summary (MCS) of the SF-8 score were below 50 T (43.47 ±â€Š9.60, 45.74 ±â€Š10.18). Depression, chronic fatigue, posttraumatic stress symptoms and stigma were negatively correlated with the SF-8 PCS and MCS. Multivariate logistic regression analysis showed that the PCS was associated with stigma (OR 8.66, 95% CI 1.96-38.23), whereas MCS was associated with depression (OR 26.62, 95% CI 3.56-198.85).The estimated HRQOL of MERS-CoV survivors during recovery was poor and appeared to be associated with depression and MERS-related stigma.

Clinical Application Study of Semi-cylindrical Beam Spoiler for Radiation Treatment of Early-stage Glottic Cancer Patients.

BACKGROUND/AIM: The purpose of this study was to determine whether a semi-cylindrical beam spoiler (sCBS) developed herein effectively increases the skin dose in patients with early-stage glottic cancer. PATIENTS AND METHODS: We measured the surface doses for 26 patients who used the sCBS during treatment of early-stage glottic cancer through a parallel-opposed lateral two-field 6 MV photon beam. Measurements were performed by attaching optically stimulated luminescent dosimeters to the left, right, anterior (in-field), inferior, and superior (out-field) sides of the patient. RESULTS: The measured results were 81.8±2.1% (left), 81.0±1.7% (right), and 76.8±2.7% (anterior) in the in-field region compared to prescription doses, with 5.7±1.7% (superior) and 2.7±0.7% (inferior) in the out-field region. CONCLUSION: sCBS can deliver a suitably ideal surface dose for treatment of early-stage glottic cancer.

Therapeutic Efficacy of Catheter-directed Ethanol Sclerotherapy and Its Impact on Ovarian Reserve in Patients with Ovarian Endometrioma at Risk of Decreased Ovarian Reserve: A Preliminary Study.

STUDY OBJECTIVE: To investigate the therapeutic efficacy of catheter-directed ethanol sclerotherapy (CDS) and its effect on ovarian reserve in patients with endometrioma at risk of decreased ovarian reserve. DESIGN: Retrospective study. SETTING: Teaching hospital. PATIENTS: We evaluated 18 patients with ovarian endometrioma measuring ≥3 cm and preprocedural serum antimüllerian hormone (AMH) levels of <2 ng/mL. INTERVENTIONS: An 8.5-F catheter was inserted either transabdominally or transvaginally into the endometrioma. After aspiration, sclerotherapy with 99% ethanol was performed, with a subsequent 20-minute ethanol retention. MEASUREMENTS AND MAIN RESULTS: Ultrasonography was performed preprocedurally and 6 months after CDS to evaluate any recurrence or changes in cyst size. Furthermore, serum AMH levels, cancer antigen 125 (CA-125) levels, and the visual analog scale scores for dysmenorrhea were obtained to analyze the ovarian reserve and treatment efficacy, preprocedurally and at 6 months after CDS. The mean cyst size on ultrasonography and serum CA-125 levels decreased 6 months after CDS (p <.001 and p = .001, respectively). All patients reported a decreased visual analog scale score for dysmenorrhea (p <.001). However, the difference in serum AMH levels before and after CDS was statistically insignificant (p = .875). CONCLUSION: CDS was efficacious in reducing pain and serum CA-125 levels in patients with low AMH levels without adversely affecting their ovarian reserve.

MicroRNA-139-5p Regulates Fibrotic Potentials via Modulation of Collagen Type 1 and Phosphorylated p38 MAPK in Uterine Leiomyoma.

PURPOSE: This study aimed to elucidate whether microRNA-139-5p is involved in the pathogenesis of uterine leiomyoma. MATERIALS AND METHODS: Human leiomyoma and matched human smooth muscle samples were obtained from 10 women who underwent hysterectomy for uterine leiomyoma. MicroRNA (miRNA) expression was analyzed by quantitative real-time polymerase chain reaction. To assess the effects of miR-139-5p on cultured leiomyoma cells, cell migration, collagen gel contraction, wound healing, and the expression levels of hallmark proteins were evaluated in cells transfected with a miR-139-5p mimic. RESULTS: The expression of miR-139-5p was significantly lower in leiomyoma tissues than in matched smooth muscle tissues. Restored miR-139-5p expression in miR-139-5p mimic-transfected human leiomyoma cells resulted in decreased contractility of the ECM and cell migration. In addition, upregulation of miR-139-5p decreased the protein expression of collagen type 1 and phosphorylated p38 MAPK. CONCLUSION: Expression of miR-139-5p is downregulated in leiomyoma cells and modulation of miR-139-5p may be involved inthe pathogenesis of leiomyomas through the regulation of collagen type 1 and phosphorylated p38 MAPK. Therefore, miR-139-5p is a potential therapeutic target for leiomyoma.

Robotic single-site versus multi-port myomectomy: a case-control study.

BACKGROUND: This study aimed to evaluate the compatibility of robotic single-site (RSS) myomectomy in comparison with the conventional robotic multi-port (RMP) myomectomy to achieve successful surgical outcomes with reliability and reproducibility. METHODS: This retrospective case-control study was performed on 236 robotic myomectomies at a university medical center. After 1:1 propensity score matching for the total myoma number, total myoma diameter, and patient age, 90 patients in each group (RSS: n = 90; RMP: n = 90) were evaluated. Patient demographics, preoperative parameters, intraoperative characteristics, and postoperative outcome measures were analyzed. RESULTS: The body mass index, parity, preoperative hemoglobin levels, mean maximal myoma diameter, and anatomical type of myoma showed no mean differences between RSS and RMP myomectomies. The RSS group was younger, had lesser number of myomas removed, and had a smaller sum of the maximal diameter of total myomas removed than the RMP group. After propensity score matching, the total operative time (RSS: 150.9 ± 57.1 min vs. RMP: 170 ± 74.5 min, p = 0.0296) was significantly shorter in the RSS group. The RSS group tended to have a longer docking time (RSS: 9.8 ± 6.5 min vs. RMP: 8 ± 6.2 min, p = 0.0527), shorter console time (RSS: 111.1 ± 52.3 min vs. RMP: 125.8 ± 65.1 min, p = 0.0665), and shorter time required for in-bag morcellation (RSS: 30.1 ± 17.2 min vs. RMP: 36.2 ± 25.7 min, p = 0.0684). The visual analog scale pain score 1 day postoperatively was significantly lower in the RSS group (RSS: 2.4 ± 0.8 days vs. RMP: 2.7 ± 0.8 days, p = 0.0149), with similar consumption of analgesic drugs. The rate of transfusion, estimated blood loss during the operation, and length of hospital stay were not different between the two modalities. No other noticeable complications were observed in either group. CONCLUSIONS: Da Vinci RSS myomectomy is a compatible option with regard to reproducibility and safety, without significantly compromising the number and sum of the maximal diameter of myomas removed. The advantage of shorter total operative time and less pain with the same amount of analgesic drugs in RSS myomectomy will contribute to improving patient satisfaction.

Hormone autocrination by vascularized hydrogel delivery of ovary spheroids to rescue ovarian dysfunctions.

The regeneration potential of implantable organ model hydrogels is applied to treat a loss of ovarian endocrine function in women experiencing menopause and/or cancer therapy. A rat ovariectomy model is used to harvest autologous ovary cells while subsequently producing a layer-by-layer form of follicle spheroids. Implantation of a microchannel network hydrogel with cell spheroids [vascularized hydrogel with ovarian spheroids (VHOS)] into an ischemic hindlimb of ovariectomized rats significantly aids the recovery of endocrine function with hormone release, leading to full endometrium regeneration. The VHOS implantation effectively suppresses the side effects observed with synthetic hormone treatment (i.e., tissue overgrowth, hyperplasia, cancer progression, deep vein thrombosis) to the normal levels, while effectively preventing the representative aftereffects of menopause (i.e., gaining fatty weight, inducing osteoporosis). These results highlight the unprecedented therapeutic potential of an implantable VHOS against menopause and suggest that it may be used as an alternative approach to standard hormone therapy.

Association between chronic fatigue syndrome and suicidality among survivors of Middle East respiratory syndrome over a 2-year follow-up period.

Suicide is an important public health issue during the current pandemic of emerging infectious diseases (EIDs). In EIDs, various symptoms persist even after recovery, and chronic fatigue is among those that are commonly reported. The aim of this study was to examine the effects of chronic fatigue syndrome on suicidality during the recovery phase among survivors of Middle East respiratory syndrome (MERS). MERS survivors were recruited from five centers and prospectively followed up for 2 years. In total, 63 participants were registered at 12 months (T1), of whom 53 and 50 completed the assessments at 18 months (T2) and 24 months (T3), respectively. Suicidality and chronic fatigue were evaluated using the suicidality module of the Mini-International Neuropsychiatric Interview (MINI) and the Fatigue Severity Scale (FSS), respectively. We analyzed the relationship between chronic fatigue and suicidality during the follow-up period using the generalized estimating equation (GEE). The suicidality rates were 22.2% (n = 14), 15.1% (n = 8), and 10.0% (n = 5) at T1-T3, respectively. Of the 63 participants, 29 had chronic fatigue syndrome at T1. The group that reported chronic fatigue syndrome at T1 was more likely to experience suicidality during the 2-year follow-up than the group that reported otherwise (RR: 7.5, 95% CI: 2.4-23.1). This association was present even after adjusting for potential confounders (RR: 7.6, 95% CI: 2.2-26.0). Chronic fatigue syndrome and suicide risk among emerging infectious disease (EID) survivors should be acknowledged, and effective interventions must be developed.

Impact of age on outcomes of midurethral sling procedures in women.

INTRODUCTION AND HYPOTHESIS: Trans-obturator tape (TOT) and tension-free vaginal tape (TVT) comprise minimally invasive surgical management for stress urinary incontinence (SUI). The aim of this retrospective cohort study was to investigate outcomes of TOT and TVT among different age groups of women. METHODS: Medical records of patients who underwent TOT and TVT from January 2010 to December 2015 were reviewed. Patients were stratified into three groups according to age. All patients were interviewed routinely before and after surgery. The primary outcome was cure rate after surgery. Secondary outcomes included hospital stay, operative time, blood loss in surgery, and complication rate. A total of 616 patients diagnosed with SUI and 262 patients who had not undergone any concurrent surgery were eligible for study inclusion. RESULTS: A total of 616 patients diagnosed with SUI and 262 patients who had not undergone any concurrent surgery were eligible for study inclusion. There were 81 patients in group 1 (≤ 50 years), 97 patients in group 2 (51-59 years), and 84 patients in group 3 (≥ 60 years). After surgery, there were no significant differences in cure rates among the three groups (96.3% vs. 94.8% vs. 97.6%, P = 0.623). There were also no significant differences in operation time, blood loss, hospital stay, and complication rate among the three groups. When analyzing the TOT group (217 patients) and TVT group (45 patients) separately, primary and secondary outcomes did not differ significantly according to age group. CONCLUSIONS: As surgical management for SUI, midurethral sling procedures, both TOT and TVT, were found to be safe and effective among different age groups.

Absorption rate of krill oil and fish oil in blood and brain of rats.

BACKGROUND: Krill (Euphausia superba) is a small marine crustacean with a lipid content. The mechanism of Krill oil function is not clear yet and research reports on the absorption rate of the phospholipids of krill oil in the blood and brain are very poor. METHODS: We studied the effect of oral short-term and long-term administration of Krill oils (KOs) on bioavailability in the blood and brain of rats. For short-term testing of fish and KO bioavailability, rats were divided into four groups: normal, fish oil (FO), Krill oil 1 (KO), and Krill oil 2 (CKO). The blood and brain were collected at 2, 4, 8, 12, 24, and 48 h after oral administration (1000 mg/rat). Five hundred milligrams of FO, KO, and CKO were orally administered daily for 2 weeks for long-term administration, and then the brain and blood were collected. RESULTS: Two types of KOs showed high content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the PL. The EPA content of CKO and KO were 41.13 and 32.49%, respectively. After short-term KO administration, KO showed a higher EPA content than CKO in the blood after 2 h. KO showed higher content of DHA than CKO even after 2 h. FO increased until 8 h, but then decreased rapidly until 12 h. Although the total unsaturated fatty acid (UFA) content of KOs was lower than the total UFS content in FO, the remaining UFS content in the brain was higher than that in FO over time. Following oral administration of FO, KO, and CKO for 1 and 2 weeks, triglycerides (TG) and PL contents in the blood for KOs were slightly higher than for FO. EPA and DHA levels in the brain were slightly higher in KOs following long-term administration, but the difference was not significant. CONCLUSIONS: Base on these findings, KOs have functional potential for the brain and vascular diseases, and can be utilized as a multi-functional material composed mainly of functional ingredients.

Elevated fecal calprotectin levels are associated with severity of atopic dermatitis in children.

BACKGROUND: Recent data suggested that imbalance in gut microbiota and gastrointestinal inflammation are associated with the childhood allergic disease. Fecal calprotectin has been used for a non-invasive marker of gut inflammation. OBJECTIVE: The aim of this study was to investigate the relationships between fecal calprotectin level and the clinical severity of atopic dermatitis (AD) in children. METHODS: We enrolled 65 subjects with AD. The concentration of calprotectin was measured in each subject's fecal sample. RESULTS: The geometric mean fecal calprotectin level of the total subjects was 33.1(10.1-108.9) µg/g. Among the 65 subjects, 44(67.7%) showed calprotectin levels lower than 50µg/g(Group 1), and 21(32.3%) were higher than 50µg/g(Group 2). The mean SCORAD index was significantly higher in Group 2 than Group 1(31.0±16.0 vs 22.2±15.3, p=0.046). The geometric mean serum total IgE levels was higher in Group 2 compared to Group 1(361.4[31.6-992.3]IU/mL vs 175.9[44.3-699.2]IU/mL, p=0.040). The mean blood eosinophils were significantly higher in Group 2 than in Group 1(497.7[239.8-1032.8]/µL vs 281.5[121.5-652.0]/µL, p=0.034). The incidence of exposure to environmental tobacco smoke was significantly higher in Group 2 compared to Group 1(76.2% vs 47.7%, p=0.036). Geometric mean fecal calprotectin level in severe AD was significantly higher than that of mild-to-moderate AD(66.7[13.5-330.3]µg/g vs 29.4[10.1-85.6]µg/g, p=0.044). The fecal calprotectin level significantly correlated with the SCORAD index(r=0.303, p=0.014). CONCLUSIONS: Higher fecal calprotectin levels were observed in subjects with severe AD. Elevated fecal calprotectin level as a gastrointestinal inflammatory marker may associate with childhood AD. Measurement of fecal calprotectin might be useful for assessment of severity of childhood AD.

Bogijetong decoction and its active herbal components protect the peripheral nerve from damage caused by taxol or nerve crush.

BACKGROUND: Bogijetong decoction (BGJTD) is a herbal drug formulation used in the traditional Asian medicine to treat neuropathic insults associated with diabetes and anticancer therapy. To understand the biological basis of BGJTD on protective effects against neuropathy, we investigated physiological and biochemical responses of the sciatic nerves deranged by taxol injection or crush injury in the rats. METHODS: Dissociated Schwann cells and neurons were prepared from the sciatic nerve and dorsal root ganglia (DRG) respectively and were treated with taxol and BGJTD. The sciatic nerve in the rat was injected with taxol or given crush injury. Animals were then administered orally with BGJTD. Effects of BGJTD treatment on cultured cells and in vivo sciatic nerves and DRG tissues were examined by immunofluorescence staining and western blot analysis. Sciatic nerve regeneration was assessed by histological observation using retrograde tracing technique and by behavioral hot plate test. Eighteen different herbal components of BGJTD were divided into 4 subgroups and were used to select herbal drugs that enhanced neurite outgrowth in cultured neurons. RESULTS: Morphological abnormalities in the sciatic nerve axons and DRG tissue caused by taxol injection were largely improved by BGJTD treatment. BGJTD treatment enhanced neurite outgrowth in cultured DRG neurons and improved Schwann cell survival. Phospho-Erk1/2 levels were elevated by BGJTD administration in the injured- or taxol-injected sciatic nerves. Vimentin phosphorylation catalyzed by cell division cycle 2 (Cdc2) kinase was induced from Schwann cells in the sciatic nerves after taxol injection and crush injury, and phospho-vimentin levels were further upregulated by BGJTD treatment. Retrograde tracing of DiI-labeled DRG sensory neurons revealed growth-promoting activity of BGJTD on axonal regeneration. A drug group (Be) composed of 4 active herbal components which were selected by neurite growth-enhancing activity was as effective as BGJDT for the recovery of thermal sensitivity of the hind paws which had been suppressed by taxol administration. CONCLUSIONS: These data suggest that BGJTD and its active herbal components may protects the peripheral nerve from damage caused by taxol injection and nerve crush.

Retinal artery occlusion by left atrial myxoma misdiagnosed as thrombus.

INTRODUCTION: Left atrial mass has been known to have a benign course. CASE DESCRIPTION: A 55-year-old Asian woman visited to our hospital because of right sided hemiparesis and sudden vision loss in her left eye. She diagnosed as acute cerebral infarction and central retinal artery occlusion by several studies. We detected a large mass in the left atrium and thought this mass as thrombus causing multiple emboli. But her neurologic symptom was aggrevated during therapy and coronary computed tomography angiogram suggested a left atrial myxoma, not thrombus. She underwent the resection of the myxoma. DISCUSSION AND EVALUATION: Sometimes it could be fatal because it could be source of systemic embolization. Moreover, when the mass is located at unusual site, it is difficult to differentiate thrombus and other benign mass. CONCLUSIONS: We report a patient with a left atrial mass initially presented as multiple embolic infarction. Our case will let ophthalmologists know about the possibility of retinal artery occlusion by cardiac myxoma.

A Case of Primary Breast Diffuse Large B-Cell Lymphoma Treated with Chemotherapy Followed by Elective Field Radiation Therapy: A Brief Treatment Pattern Review from a Radiation Oncologist's Point of View.

We here report a case of primary breast lymphoma (PBL). A 44-year-old woman presented with a painless mass in the right breast. Fine needle aspiration cytology and excisional biopsy were performed. Excisional biopsy revealed low grade lymphoma, which was subsequently confirmed with histopathology and diagnosed as diffuse large B-cell lymphoma (DLBCL). A chest computed tomography scan revealed a 3.5 cm sized breast mass with skin thickening and a small sized lymphadenopathy in the ipsilateral axilla. Radiation therapy including the right whole breast and ipsilateral axilla and supraclavicular lymph node was performed after the patient received four courses of R-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone plus rituximab) chemotherapy. At the follow-up period of 42 months, the patient is surviving with no evidence of disease. No morbidities occurred in this patient during the follow-up period. We also briefly review the current practice pattern in PBL patients with DLBCL.

Clinical applicability of biologically effective dose calculation for spinal cord in fractionated spine stereotactic body radiation therapy.

BACKGROUND: The aim of the study was to investigate whether biologically effective dose (BED) based on linear-quadratic model can be used to estimate spinal cord tolerance dose in spine stereotactic body radiation therapy (SBRT) delivered in 4 or more fractions. PATIENTS AND METHODS: Sixty-three metastatic spinal lesions in 47 patients were retrospectively evaluated. The most frequently prescribed dose was 36 Gy in 4 fractions. In planning, we tried to limit the maximum dose to the spinal cord or cauda equina less than 50% of prescription or 45 Gy2/2. BED was calculated using maximum point dose of spinal cord. RESULTS: Maximum spinal cord dose per fraction ranged from 2.6 to 6.0 Gy (median 4.3 Gy). Except 4 patients with 52.7, 56.4, 62.4, and 67.9 Gy2/2, equivalent total dose in 2-Gy fraction of the patients was not more than 50 Gy2/2 (12.1-67.9, median 32.0). The ratio of maximum spinal cord dose to prescription dose increased up to 82.2% of prescription dose as epidural spinal cord compression grade increased. No patient developed grade 2 or higher radiation-induced spinal cord toxicity during follow-up period of 0.5 to 53.9 months. CONCLUSIONS: In fractionated spine SBRT, BED can be used to estimate spinal cord tolerance dose, provided that the dose per fraction to the spinal cord is moderate, e.g. < 6.0 Gy. It appears that a maximum dose of up to 45-50 Gy2/2 to the spinal cord is tolerable in 4 or more fractionation regimen.