Optimal set of grid size and angular increment for practical dose calculation using the dynamic conformal arc technique: a systematic evaluation of the dosimetric effects in lung stereotactic body radiation therapy

Purpose To recommend the optimal plan parameter set of grid size and angular increment for dose calculations in treatment planning for lung stereotactic body radiation therapy (SBRT) using dynamic conformal arc therapy (DCAT) considering both accuracy and computational efficiency. Materials and methods Dose variations with varying grid sizes (2, 3, and 4 mm) and angular increments (2°, 4°, 6°, and 10°) were analyzed in a thorax phantom for 3 spherical target volumes and in 9 patient cases. A 2-mm grid size and 2° angular increment are assumed sufficient to serve as reference values. The dosimetric effect was evaluated using dose–volume histograms, monitor units (MUs), and dose to organs at risk (OARs) for a definite volume corresponding to the dose–volume constraint in lung SBRT. The times required for dose calculations using each parameter set were compared for clinical practicality. Results Larger grid sizes caused a dose increase to the structures and required higher MUs to achieve the target coverage. The discrete beam arrangements at each angular increment led to over- and under-estimated OARs doses due to the undulating dose distribution. When a 2° angular increment was used in both studies, a 4-mm grid size changed the dose variation by up to 3–4% (50 cGy) for the heart and the spinal cord, while a 3-mm grid size produced a dose difference of \u3c1% (12 cGy) in all tested OARs. When a 3-mm grid size was employed, angular increments of 6° and 10° caused maximum dose variations of 3% (23 cGy) and 10% (61 cGy) in the spinal cord, respectively, while a 4° increment resulted in a dose difference of \u3c1% (8 cGy) in all cases except for that of one patient. The 3-mm grid size and 4° angular increment enabled a 78% savings in computation time without making any critical sacrifices to dose accuracy. Conclusions A parameter set with a 3-mm grid size and a 4° angular increment is found to be appropriate for predicting patient dose distributions with a dose difference below 1% while reducing the computation time by more than half for lung SBRT using DCAT

Evaluation of three glucometers for whole blood glucose measurements at the point of care in preterm or low-birth-weight infants

PurposeWe evaluated three blood glucose self-monitoring for measuring whole blood glucose levels in preterm and low-birth-weight infants.MethodsBetween December 1, 2012 and March 31, 2013, 230 blood samples were collected from 50 newborns, who weighed, ≤2,300 g or were ≤36 weeks old, in the the neonatal intensive care unit of Eulji University Hospital. Three blood glucose self-monitoring (A: Precision Pcx, Abbott; B: One-Touch Verio, Johnson & Johnson; C: LifeScan SureStep Flexx, Johnson & Johnson) were used for the blood glucose measurements. The results were compared to those obtained using laboratory equipment (D: Advia chemical analyzer, Siemens Healthcare Diagnostics Inc.).ResultsThe correlation coefficients between laboratory equipment and the three blood glucose self-monitoring (A, B, and C) were found to be 0.888, 0.884, and 0.900, respectively. For glucose levels≤60 mg/dL, the correlation coefficients were 0.674, 0.687, and 0.679, respectively. For glucose levels>60 mg/dL, the correlation coefficients were 0.822, 0.819, and 0.839, respectively. All correlation coefficients were statistically significant. And the values from the blood glucose self-monitoring were not significantly different from the value of the laboratory equipment , after correcting for each device's average value (P>0.05). When using laboratory equipment (blood glucose ≤60 mg/dL), each device had a sensitivity of 0.458, 0.604, and 0.688 and a specificity of 0.995, 0.989, and 0.989, respectively.ConclusionSignificant difference is not found between three blood glucose self-monitoring and laboratory equipment. But correlation between the measured values from blood glucose self-monitoring and laboratory equipment is lower in preterm or low-birth-weight infants than adults

Health effects from exposure to dental diagnostic X-ray

The purpose of this review is to summarize the results of studies on of the association between exposure to dental X-rays and health risk. To perform the systematic review, We searched the PUBMED, EMBASE, and MEDLINE databases for papers published before December 15, 2016. A total of 2 158 studies, excluding duplicate studies, were found. Two reviewers independently evaluated the eligibility of each study. The final 21 studies were selected after application of exclusion criteria. In terms of health outcomes, there were 10 studies about brain tumors, 5 about thyroid cancer, 3 about tumors of head and neck areas, and 3 related to systemic health. In brain tumor studies, the association between dental X-ray exposure and meningioma was statistically significant in 5 of the 7 studies. In 4 of the 5 thyroid-related studies, there was a significant correlation with dental diagnostic X-rays. In studies on head and neck areas, tumors included laryngeal, parotid gland, and salivary gland cancers. There was also a statistically significant correlation between full-mouth X-rays and salivary gland cancer, but not parotid gland cancer. Health outcomes such as leukemia, low birth weight, cataracts, and thumb carcinomas were also reported. In a few studies examining health effects related to dental X-ray exposure, possibly increased risks of meningioma and thyroid cancer were suggested. More studies with a large population and prospective design are needed to elaborate these associations further

Congenital Cerebellar Mixed Germ Cell Tumor Presenting with Hemorrhage in a Newborn

We report here on a neonate with congenital cerebellar mixed germ cell tumor, and this initially presented as cerebellar hemorrhage. Postnatal cranial ultrasonography revealed an echogenic cerebellar mass that exhibited the signal characteristics of hemorrhage rather than tumor on MR images. The short-term follow-up images also suggested a resolving cerebellar hemorrhage. One month later, the neonate developed vomiting. A second set of MR images demonstrated an enlarged mass that exhibited changed signal intensity at the same site, which suggested a neoplasm. Histological examination after the surgical resection revealed a mixed germ cell tumor

A case of primary hepatic actinomycosis: an enigmatic inflammatory lesion of the liver

Primary hepatic actinomycosis is one of the chronic abscess-forming infections of the liver. Accurate diagnosis is frequently delayed due to its indolent course and nonspecific clinical and radiological manifestations. We report a case of a 57-year-old man presenting with asymptomatic multiple hepatic masses on follow-up abdominal computed tomography performed 1 year after stomach cancer surgery. Although a percutaneous liver biopsy procedure was conducted twice in order to obtain confirmative pathology, only a nonspecific organizing abscess with plasma cell infiltration was revealed, without identification of any organism in the tissue cultures. Ultimately, actinomycosis was diagnosed following the detection of sulfur granules on open surgical biopsied tissue. This case suggests that primary hepatic actinomycosis should be considered as one of the possible causes for enigmatic inflammatory lesions of the liver

A Case of Non-Hodgkin's Lymphoma in Patient with Coombs' Negative Hemolytic Anemia and Idiopathic Thrombocytopenic Purpura

Coombs' negative autoimmune hemolytic anemia (AIHA) is a rare disease which shares similar clinical and hematological features with Coombs' positive AIHA, but its exact frequency remains unknown. There have been few reports of idiopathic thrombocytopenic purpura (ITP) and Coombs' negative AIHA associated with other lymphoproliferative disorders (LPDs). Since there is a well known association between LPDs and autoimmune phenomena, it is important to investigate the possibility of an underlying malignancy. We report a case of ITP and Coombs' negative AIHA associated with diffuse large B-cell lymphoma