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Background/aim To evaluate the incidence and grade of radiation pneumonitis after volumetric modulated arc therapy (VMAT) performed for the treatment of non-small cell cancer (NSCLC). Patients and methods Fifty consecutive non-surgical candidates with NSCLC underwent VMAT. Thirty-five patients had stage-III tumors and 15 had recurrent tumors. The prescribed radiation dose for the gross tumor and the elective nodal area was 69 Gy in 30 fractions and 51 Gy in 30 fractions, respectively. Results Radiation pneumonitis developed in 38 patients (76%, 38/50), and grade ≥2 radiation pneumonitis developed in 11 patients (22%, 11/50). The percentage of lung volume that received a dose in excess of 5 Gy (V5), V10, V20, V30, and the mean lung dose (MLD) in the bilateral and ipsilateral lung were significantly associated with the development of grade ≥2 radiation pneumonitis. Conclusion The incidence and degree of radiation pneumonitis are acceptable following treatment of NSCLC with VMAT.

Background Cardiac rehabilitation (CR) is an essential component of care for patients with cardiovascular diseases (CVD). We aimed to evaluate clinical outcomes in outpatients with CVD who did and did not complete a 5-month CR program. Methods Three hundred thirty-two outpatients with CVD who participated in a 5-month CR program and were followed-up for maximum 5 years were registered. We divided the patients into two groups: those who completed the CR program (success group, n = 175) and those who could not (non-success group, n = 157). Both long-term (5 years) and short-term (5 months) clinical outcomes were compared between the two groups. Results There were no significant differences in patient characteristics at baseline between the success and non-success groups. With regard to both long-term and short-term clinical outcomes, the rates of all-cause death and hospital admission in the success group were significantly lower than those in the non-success group by a Kaplan-Meier analysis. There was a significant difference in short-term CVD death and hospital admission between the groups, but not for long-term CVD death and hospital. In long-term period, all-cause death and hospital admission was independently associated with completion of the CR program in addition to the presence of peripheral artery disease and VE vs. VCO2 slope after adjusting for age, gender, body mass index, types of CVD and medications. Conclusions Completion of a 5-month CR program was associated with the prevention of all-cause death and hospital admission, but not CVD death and hospital admission in the long-term, which suggests that we need to reconsider this issue.

Aim This study aimed to assess the utility and stability of intraoral stent during intensity-modulated radiation therapy (IMRT). Background The benefits of intraoral stents in radiotherapy are unclear. Materials and methods We analyzed 386 setup errors in 12 patients who received IMRT for head and neck cancers without intraoral stents (intraoral stent [−]) and 183 setup errors in 6 patients who received IMRT with intraoral stents (intraoral stent [+]). All patients were matched according to the immobilization method (masks and boards). Setup errors were measured as the distance from the initial setup based on the marking on the skin and mask to the corrected position based on bone matching on cone beam computed tomography. Results The mean interfractional setup errors in the right–left, craniocaudal, anterior–posterior (AP), and three-dimensional (3D) directions were −0.33, 0.08, −0.25, and 2.75 mm in the intraoral stent (−) group and −0.37, 0.24, −0.63, and 2.42 mm in the intraoral stent (+) group, respectively ( P = 0.50, 0.65, 0.01, and 0.02, respectively). The systematic errors for the same directions were 0.89, 1.46, 1.15, and 0.88 mm in the intraoral stent (−) group and 0.62, 1.69, 0.68, and 0.56 mm in the intraoral stents (+) group, respectively. The random errors were 1.43, 1.43, 1.44, and 1.22 mm in the intraoral stent (−) group and 1.06, 1.11, 1.05, and 0.92 mm in the intraoral stents (+) group, respectively. Conclusion Setup errors can be significantly reduced in the AP and 3D-directions by using intraoral stents.

Deformable image registration (DIR) has been an important component in adaptive radiotherapy (ART). Our goal was to examine the accuracy of ART using the dice similarity coefficient (DSC) and to determine the optimal timing of replanning. A total of 22 patients who underwent volume modulated arc therapy (VMAT) for head and neck (H&N) cancers were prospectively analyzed. The planning target volume (PTV) was to receive a total of 70 Gy in 33 fractions. A second planning CT scan (rescan) was performed at the 15th fraction. The DSC was calculated for each structure on both CT scans. The continuous variables to predict the need for replanning were assessed. The optimal cut-off value was determined using receiver operating characteristic (ROC) curve analysis. In the correlation between body weight loss and DSC of each structure, weight loss correlated negatively with DSC of the whole face (rs = -0.45) and the face surface (rs = -0.51). Patients who required replanning tended to have experienced rapid weight loss. The threshold DSC was 0.98 and 0.60 in the whole face and the face surface, respectively. Patients who showed low DSC in the whole face and the face surface required replanning at a significantly high rate (P < 0.05 and P < 0.01). Weight loss correlated with DSC in both the whole face and the face surface (P < 0.05 and P < 0.05). The DSC values in the face predicted the need for replanning. In addition, weight loss tended to correlate with DSC. DIR during ART was found to be a useful tool for replanning.

Background: Visit-to-visit variability (VVV) in blood pressure (BP) has been shown to be a strong predictor of cardiovascular disease (CVD). However, the long-term effect of comprehensive cardiac rehabilitation (CR) with exercise training on VVV in BP has not yet been established. Therefore, we evaluated the long-term effects of CR on VVV in BP in patients with CVD. Methods: Twenty-two CVD patients in a 12-month CR program who had at least six clinic visits per month to measure BP were enrolled. We determined VVV in BP expressed as the standard deviation of average BP every month for 12 months. Results: The mean age was 70 ± 8 years and the body mass index was 24.4 ± 4.9 kg/m 2 . In addition, the percentage (%) of males, % heart failure and % ischemic heart disease were 77%, 55% and 27%, respectively. Patients who had uncontrolled BP at baseline showed a significant reduction of both systolic BP (SBP) and diastolic BP (DBP). VVV in SBP in the first month was significantly less than that in the last month, although there was no difference in VVV in DBP. Patients were divided into larger (L-) and smaller (S-) VVV in SBP groups according to the average value of VVV in SBP as a cut-off. The L-VVV in SBP group, but not the S-VVV in SBP group, showed a significant reduction of VVV in SBP. Conclusion: Comprehensive CR may improve VVV in SBP in CVD patients who have larger VVV in SBP. J Clin Med Res. 2017;9(4):345-352 doi: https://doi.org/10.14740/jocmr2915w

Cardiac rehabilitation (CR) improves cardiac function and exercise capacity in patients with cardiovascular disease (CVD). Simpler techniques are needed for use by physicians in the examination room to assess the usefulness of CR. We enrolled 46 consecutive CVD patients in a CR program (CR group) and prospectively followed them for 3months. We compared them to 18 age-, gender- and body mass index-matched CVD patients without CR (non-CR group). Various parameters were measured at baseline and after 3months using 3 simple non-invasive tests: severity of atherosclerosis [arterial velocity pulse index and arterial pressure volume index (API)] were determined using PASESA®, an autonomic nerve total activity amount index and a coefficient of variation of the R–R interval (CVRR) were determined using eHEART®, and peripheral resistance index, pressure rate product, stroke volume and cardiac index were determined using nico®]. There were no significant differences in patient characteristics including percentages (%) of ischemic heart disease and heart failure between the non-CR and CR groups. Systolic blood pressure (SBP), diastolic BP, heart rate and API at baseline significantly decreased and CVRR at baseline significantly increased after 3months in the CR group, but not in the non-CR group. In addition, ΔAPI (Δ=the value after 3months minus the value at baseline) was positively associated with ΔSBP in the CR group. In conclusion, CR significantly decreased BP and improved atherosclerosis and sympathetic nerve activity. These findings suggest that simple non-invasive tests may be useful for assessing the effects of CR.

Visit-to-visit variability (VVV) in blood pressure (BP) has been shown to be a predictor of cardiovascular events. It is unknown whether CR can improve VVV in BP as well as reducing BP. We enrolled 84 patients who had cardiovascular disease (CVD) and participated in a 3-month CR program. We measured systolic and diastolic BP (SBP and DBP), pulse pressure (PP), and heart rate (HR) before exercise training at each visit and determined VVV in BP or HR expressed as the standard deviation of the average BP or HR. Patients who had uncontrolled BP at baseline and who did not change their antihypertensive drugs throughout the study period showed a significant reduction of both SBP and DBP with a decrease in PP after 3 months. Patients who did not change their antihypertensive drugs were divided into larger (L-) and smaller (S-) VVV in the SBP groups and L- and S-VVV in the DBP groups according to the average value of VVV in SBP or DBP. In the L-VVV in the SBP and DBP groups, VVV in SBP and DBP in the 1st month was significantly decreased after the 3rd month in both groups. HR at baseline was significantly decreased after 3 months. In addition, CR induced a significant increase in the level of high-density lipoprotein cholesterol (HDL-C) in blood. In conclusion, CR improved VVV in BP in patients with L-VVV in BP and evoked a significant reduction in HR and an increase in HDL-C. These effects due to the CR program may be cardioprotective.

The purpose of this paper is to study the core performance of passive safety small reactor for distributed energy supply by changing the heavy water (D2O) concentration in the mixed coolant together with the fuel pitch. The long core life with conditions of the excessive reactivity of 2 %Δk/k, the reactivity shutdown margin of 1 %Δk/k and the negative coolant temperature reactivity coefficient is attained for the case of D2O concentration of 60% with 10% enrichment gadolinia (Gd2O3) doped fuel rods. This D2O core has a shorter core life 4.14 years than the original light water (H2O) core 4.76 years, while it needs a larger core size. However, changing the D2O concentration on the way during the burn-up shows a possibility of extending more the core life than that of the original H2O core.

DRX is a very small integral type PWR (750 kW t ) for a scientific deep-sea research bathyscaph. The core having a small amount of steam is cooled by natural circulation and pressurized by self-pressurization. During operation of the bathyscaph in a deep sea or near the water surface, a ship inclination or ship motions will affect the reactor behavior. This paper describes the effect of a heeling or a heaving on the thermal hydraulic behavior of reactor system, which is analyzed by retran-02/grav improved so to simulate the effect of ship motions. The dynamics has a feature of nuclear power-natural circulation flow coupling under the condition of external forces. The analysis shows that ship inclination induces the core flow to decrease but reactor power recovers to the initial level without help of the reactor automatic control system. The heaving makes the core flow and the reactor power oscillate in phase with heaving, which are different from a density wave oscillation. Oscillation amplitudes of the flow and the power have peaks at the heaving period of 5 s. The peaks are due to resonance of the natural circulation flow and the heaving. An effective measure to suppress this oscillations due to heaving is to pressurize the primary loop by filling non-condensable gas. The density wave oscillation occurs when the reactor power increases over the rated power, and the boundary of its occurrence is analytically revealed. Under the condition of both density wave oscillation and heaving, the system shows to oscillate with the overlapped effect.

The basic concept of an innovative advanced marine reactor with a passive safety system, MRX (Marine Reactor X) has been established for the primary application to ship propulsion. The design goals of the reactor system, to be lightweight and compact, and to be enhanced in safety and reliability, are achieved with adoption of new technologies. The MRX is of the integral-type PWR with 100 MW of thermal output. Adoption of a water-filled containment makes the MRX extremely lightweight and compact. The total weight and volume of MRX is about 1600 tons and 1210 m3, which is half that of the first Japanese nuclear ship, ‘Mutsu’, reactor, although the reactor power of MRX is three times greater than that of the ‘Mutsu’ reactor. Numbers of active components in the reactor system are greatly reduced, compared with loop type PWRs, by adopting an integral type reactor and the passive system. Safety was evaluated by both experiments and analyses. Core damage occurrence frequency estimated by probability safety analysis (PSA) is of two orders smaller than those of existing PWRs. Feasibility study on economics is conducted by comparing the total operation costs of a nuclear container ship installing the MRXs with a diesel engine ship. The nuclear ship has the advantage for greater speed and larger amounts of cargo carried.

A simple method is presented to calculate radiation streaming through cylindrical ducts in a concrete shield. It includes neutron and gamma-ray calculations and can be applied to the problems of practical slant incidence. The method is essentially one of summing the axial dose rates from the different neutron and gamma components which are functions of energy and angle of incident radiation, duct diameter, bend angle, etc. Axial dose rates are calculated by the MCNP Monte Carlo code for straight and bent ducts having diameters of 5,10,20,30 and 40 cm. Radiation sources are plane mono-directional fission neutrons, intermediate neutrons, thermal neutrons and 1.25-MeV gamma rays. Incident angles are 0, 15, 30, 45 and 60 deg for straight ducts. For bent ducts, an isotropic plane source is placed inside the duct mouth to reduce computation time. Bend angles are 30,45,60 and 90 deg. Reliability of the Monte Carlo calculations are assessed by comparison with a 60Co experiment and calculations by the one-dimensio...