The pullback pressure from the left renal vein (LRV) to the inferior vena cava was studied in 16 patients with left renal bleeding of unknown origin (group A), 15 patients with hematuria of miscellaneous laterality (group B), and nine control subjects (group C). The mean pressure gradients were 5.0 +/- 2.0 mm Hg (mean +/- SD) in group A, 1.9 +/- 1.0 mm Hg in group B, and 1.1 +/- 0.9 mm Hg in group C. The mean pressure gradient of group A was significantly higher than that of groups B and C (P less than .001). From the results of control studies, we regarded pressure gradients greater than or equal to 3.0 mm Hg as indicative of LRV hypertension. With this criterion, 88% (14 of 16) of the patients in group A had LRV hypertension, which was considered a cause of hematuria. Analysis of the results of renal angiography in the 31 patients revealed that opacification of collateral pathways of the LRV was a significant angiographic finding in LRV hypertension.
Inter-individual variability exceeded intra-individual variability for 2 of 4 endpoints examined for ssb repair, but not for dsb repair. It was concluded that DNA damage measured using the comet assay could identify a range in the X-ray repair responses of WBC from different normal individuals. Whether these differences correlate with differences in cell killing by radiation remains to be determined.
Purpose: To predict local recurrence (LR) and distant metastasis (DM) in early stage non-small cell lung cancer (NSCLC) patients after stereotactic body radiotherapy (SBRT) in multiple institutions using breath-hold computed tomography (CT)-based radiomic features with random survival forest. Methods: A total of 573 primary early stage NSCLC patients who underwent SBRT between January 2006 and March 2016 and met the eligibility criteria were included in this study. Patients were divided into two datasets: training (464 patients in 10 institutions) and test (109 patients in one institution) datasets. A total of 944 radiomic features were extracted from manually segmented gross tumor volumes (GTVs). Feature selection was performed by analyzing inter-segmentation reproducibility, GTV correlation, and inter-feature redundancy. Nine clinical factors, including histology and GTV size, were also used. Three prognostic models (clinical, radiomic, and combined) for LR and DM were constructed using random survival forest (RSF) to deal with total death as a competing risk in the training dataset. Robust models with optimal hyper-parameters were determined using fivefold cross-validation. The patients were dichotomized into two groups based on the median value of the patient-specific risk scores (high-and low-risk score groups). Gray's test was used to evaluate the statistical significance between the two risk score groups. The prognostic power was evaluated by the concordance index with the 95% confidence intervals (CI) via bootstrapping (2000 iterations). Results: The concordance indices at 3 yr of clinical, radiomic, and combined models for LR were 0.57 [
The aim of this study was to survey the current status of reirradiation (Re-RT) and
patterns of practice in Japan. An email questionnaire was sent to Kansai Cancer Therapist
Group partner institutions, using questions similar to those in the Canadian radiation
oncologist (RO) survey (2008). A total of 34 ROs from 28 institutions returned the survey.
All 28 institutions experienced Re-RT cases in 2014. However, 26 of the 28 institutions
(93%) reported difficulty in obtaining Re-RT case information from their respective
databases. Responses from 19 institutions included the number of Re-RT cases; this rose
from 183 in the period 2005–2009 (institution median = 4; 2–12.9) to 562 in the period
2010–2014 (institution median = 26; 2–225). Important considerations for indication of
Re-RT were age (65%), performance status (83%), life expectancy (70%), absence of distant
metastases (67%), and interval since previous treatment (73%). Previous total radiation
dose (48%), volume of tissue irradiated (72%), and the biologically equivalent dose (BED;
68.5%) were taken into account during Re-RT planning. These factors were similar to those
considered in the Canadian survey; however, the present study did not consider age. In
eight site-specific scenarios, barring central nervous system recurrence, more than 90% of
ROs agreed to perform Re-RT, which was higher than the percentage observed in the Canadian
survey. Re-RT cases have increased in number and aroused interest among ROs in this decade
of advanced technology. However, consensus building to establish guidelines for the
practice and prospective evaluation of Re-RT is required.
To determine the radiosensitivity of non-S-phase tumour cells in vitro, survival curves of SCC VII tumour cells were obtained after a short block with hydroxyurea. Dose-response curves of micronucleus (MN) frequency appearing in non-S-phase cells were also determined by excluding S-phase cells with immunofluorescence staining to 5-bromo-2'-deoxyuridine (BUdR). Both the dose-response curves of MN frequency and survival curves were analysed by a linear-quadratic model (surviving fraction = exp (-alpha D-beta D2), MN frequency = aD+bD2+c). A good correlation between the alpha/beta and alpha/beta ratios was observed. In both BUdR-unincorporated and asynchronous cell cultures, the regression lines between the surviving fraction and micronucleus frequency were statistically identical. Therefore, it was shown that cell survival curves, which cannot be obtained directly by the routine colony-formation technique, can be calculated using the micronucleus frequency and the regression line in asynchronous cell cultures. Therefore, it should be possible to detect the response to irradiation of quiescent cells in tumours using the immunofluorescence staining to BUdR and the MN frequency assay.
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