• IMMUNE NETWORK
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• v.3 no.2
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• pp.103-109
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• 2003

Background: As all HLA class II genes, the DQ genes show their polymorphic variation mainly in the second exon, which encodes the first extracellular domain of the molecule. PCR-SSOP (Polymerase chain reaction-Sequence specific oligonucleotide probe) techniques were frequently used for HLA-DQA1 and DQB1 typing but certain alleles, $DQA1^*0101/0104/0105$, $^*302/0303$, $*0501/0505$ and $DQB1^*0201/^*0202$ which differ from each other in segment other than exon 2, could not be unequivocally assigned. Methods: To overcome this problem, we applied additional PCR-SSP (PCR-Sequence specific primer) method to analyze DQA1 exons 1, 3 and 4 and DQB1 exon 3. And we investigated the distributions and haplotypes of HLA-DRB1, DQA1 and DQB1 alleles in 406 unrelated Korean healthy individuals. Results: Using this method the indistinguishable alleles of DQA1 and DQB1 in PCR-SSOP were typed definitively. We also found several important associations between DQA1 and DQB1 alleles in the Korean population; $DQA1^*0101-DQB1^*0501$, $DQA1^*0104-DQB1^*0502$ or $-^*0503$, $DQA1^*0105-DQB1^*0501$, $DQA1^*0302-DQB1^*0303$, $DQA1^*0303-DQB1^*0401$ or $-^*0402$, $DQA1^*0501-DQB1^*0201$, $DQA1^*0505-DQB1^*0301$, and $DQA1^*0201-DQB1^*0202$. The haplotypes of DRB1-DQA1-DQB1 associated with $DQA1^*01$, $^*03$, $^*05$, and $DQB1^*02$ subtypes were investigated. Several haplotypes associated with these alleles were observed in the Korean population. Conclusion: Our results can be helpful to find potential unrelated donors for bone marrow registries and study the HLA-associated disease and anthropology at high-resolution allelic level.

• Journal of radiological science and technology
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• v.45 no.5
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• pp.439-448
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• 2022

The purpose of this study was to analyze the results from statistical process control (SPC) to recommend upper and lower control limits for planning parameters based on delivery quality assurance (DQA) results and establish our institutional guidelines regarding planning parameters for helical tomotherapy (HT). A total of 53 brain, 41 head and neck (H & N), and 51 pelvis cases who had passing or failing DQA measurements were selected. The absolute point dose difference (DD) and the global gamma passing rate (GPR) for all patients were analyzed. Control charts were used to evaluate upper and lower control limits (UCL and LCL) for all assessed treatment planning parameters. Treatment planning parameters were analyzed to provide its range for DQA pass cases. We confirmed that the probability of DQA failure was higher when the proportion of leaf open time (LOT) below 100 ms was greater than 30%. LOT and gantry period (GP) were significant predictor for DQA failure using the SPC method. We investigated the availability of the SPC statistic method to establish the local planning guideline based on DQA results for HT system. The guideline of each planning parameter in HT may assist in the prediction of DQA failure using the SPC statistic method in the future.

• Progress in Medical Physics
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• v.28 no.4
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• pp.181-189
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• 2017

The conventional delivery quality assurance (DQA) process for RapidArc (Varian Medical Systems, Palo Alto, USA), has the limitation that it measures and analyzes the dose in a phantom material and cannot analyze the dosimetric changes under the motional organ condition. In this study, a DQA method was designed to overcome the limitations of the conventional DQA process for internal target volume (ITV) based RapidArc. The dynamic DQA measurement device was designed with a moving phantom that can simulate variable target motions. The dose distribution in the real volume of the target and organ-at-risk (OAR)s were reconstructed using 3DVH with the ArcCHECK (SunNuclear, Melbourne, USA) measurement data under the dynamic condition. A total of 10 ITV-based RapidArc plans for liver-cancer patients were analyzed with the designed dynamic DQA process. The average pass rate of gamma evaluation was $81.55{\pm}9.48%$ when the DQA dose was measured in the respiratory moving condition of the patient. Appropriate method was applied to correct the effect of moving phantom structures in the dose calculation, and DVH data of the real volume of target and OARs were created with the recalculated dose by the 3DVH program. We confirmed the valid dose coverage of a real target volume in the ITV-based RapidArc. The variable difference of the DVH of the OARs showed that dose variation can occur differently according to the location, shape, size and motion range of the target. The DQA process devised in this study can effectively evaluate the DVH of the real volume of the target and OARs in a respiratory moving condition in addition to the simple verification of the accuracy of the treatment machine. This can be helpful to predict the prognosis of treatment by the accurate dose analysis in the real target and OARs.

• Journal of radiological science and technology
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• v.46 no.3
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• pp.231-238
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• 2023

This study aimed to compare the results of delivery quality assurance (DQA) using MapCHECK and OCTAVIUS for radiation therapy. Thirty patients who passed the DQA results were retrospectively included in this study. The point dose difference (DD) and gamma passing rate (GPR) were analyzed to evaluate the agreement between the measured and planned data for all cases, Plan complexity was evaluated to analyze dosimetric accuracy by quantifying the degree of modulation according to each plan. We analyzed the monitor units (MUs) and total MUs for each plan to evaluate the correlation between the MUs and plan complexity. We used a paired t-test to compare the DD and GPRs that were obtained using the two devices. The DDs and GPRs were within the tolerance range for all cases. The average GPRs difference between the two devices was statistically significant for the brain, and head and neck for gamma criteria of 3%/3 mm and 2%/2 mm. There was no significant correlation between the modulation index and total MUs for any of the cases. These DQA devices can be used interchangeably for routine patient-specific QA in radiation therapy.

• Journal of Radiation Protection and Research
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• v.36 no.4
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• pp.183-189
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• 2011

To quantitatively evaluate how setup errors in conjunction with dose gradients contribute to the error in IMRT dose quality assurance (DQA) measurements. The control group consisted of 5 DQA plans of which all individual field dose differences were less than ${\pm}5%$. On the contrary, the examination group was composed of 16 DQA plans where any individual field dose difference was larger than ${\pm}10%$ even though their total dose differences were less than ${\pm}5%$. The difference in 3D dose gradients between the two groups was estimated in a cube of $6{\times}6{\times}6\;mm^3$ centered at the verification point. Under the assumption that setup errors existed during the DQA measurements of the examination group, a three dimensional offset point inside the cube was sought out, where the individual field dose difference was minimized. The average dose gradients of the control group along the x, y, and z axes were 0.21, 0.20, and 0.15 $cGy{\cdot}mm^{-1}$, respectively, while those of the examination group were 0.64, 0.48, and 0.28 $cGy{\cdot}mm^{-1}$, respectively. All 16 plans of the examination group had their own 3D offset points in the cube. The individual field dose differences recalculated at the offset points were mostly diminished and thus the average values of total and individual field dose differences were reduced from 3.1% to 2.2% and 15.4% to 2.2%, respectively. The offset distribution turned out to be random in the 3D coordinate. This study provided the quantitative data that support the large individual field dose difference mainly stems from possible geometric errors (e.g., random setup errors) under the influence of steep dose gradients of IMRT field.

• Journal of radiological science and technology
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• v.45 no.6
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• pp.491-502
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• 2022

The purpose of this study was to retrospectively investigate the upper and lower control limits of treatment planning parameters using EBT film based delivery quality assurance (DQA) results and to analyze the results of statistical process control (SPC) in helical tomotherapy (HT). A total of 152 patients who passed or failed DQA results were retrospectively included in this study. Prostate (n = 66), rectal (n = 51), and large-field cancer patients, including lymph nodes (n = 35), were randomly selected. The absolute point dose difference (DD) and global gamma passing rate (GPR) were analyzed for all patients. Control charts were used to evaluate the upper and lower control limits (UCL and LCL) for all the assessed treatment planning parameters. Treatment planning parameters such as gantry period, leaf open time (LOT), pitch, field width, actual and planning modulation factor, treatment time, couch speed, and couch travel were analyzed to provide the optimal range using the DQA results. The classification and regression tree (CART) was used to predict the relative importance of variables in the DQA results from various treatment planning parameters. We confirmed that the proportion of patients with an LOT below 100 ms in the failure group was relatively higher than that in the passing group. SPC can detect QA failure prior to over dosimetric QA tolerance levels. The acceptable tolerance range of each planning parameter may assist in the prediction of DQA failures using the SPC tool in the future.

• Progress in Medical Physics
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• v.21 no.4
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• pp.340-347
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• 2010

DQA, a patient specific quality assurance in tomotherapy, is usually performed using an ion chamber and a film. The result of DQA is analysed with the treatment planning system called Tomo Planning Station (TomoPS). The two-dimensional dose distribution of film measurement is compared with the dose distribution calculated by TomoPS using the ${\gamma}$-index analysis. In ${\gamma}$-index analysis, the criteria such as 3%/3 mm is used and we verify that whether the rate of number of points which pass the criteria (pass rate) is within tolerance. TomoPS does not provide any quantitative information regarding the pass rate. In this work, a method to get the pass rate of the ${\gamma}$-index analysis was suggested and a software PassRT which calculates the pass rate was developed. The results of patient specific QA of the intensity modulated radiation therapy measured with I'mRT MatriXX (IBA Dosimetry, Germany) and DQA of tomotherapy measured with film were used to verify the proposed method. The pass rate was calculated using PassRT and compared with the pass rate calculated by OmniPro I'mRT (IBA Dosimetry, Germany). The average difference between the two pass rates was 0.00% for the MatriXX measurement. The standard deviation and the maximum difference were 0.02% and 0.02%, respectively. For the film measurement, average difference, standard deviation and maximum difference were 0.00%, 0.02% and 0.02%, respectively. For regions of interest smaller than $24.3{\times}16.6cm^2$ the proposed method can be used to calculate the pass rate of the gamma index analysis to one decimal place and will be helpful for the more accurate DQA in tomotherapy.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1247-1251
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• 2012

Background: Helicobacter pylori is an important gastrointestinal pathogen related to the development of not only atrophic gastritis and peptic ulcer, but also gastric cancer. Human leukocyte antigens (HLA) may play particular roles in host immune responses to bacterial antigens. This study aimed to investigate the association between HLA-DQA1 and DQB1 genotypes and haplotypes vs H. pylori infection in an Indonesian population. Methods: We selected 294 healthy participants in Mataram, Lombok Island, Indonesia. H. pylori infection was determined by urea breath test (UBT). We analyzed HLA-DQA1 and DQB1 genotypes by PCR-RFLP and constructed haplotypes of HLA-DQA1 and DQB1 genes. Multiple comparisons were conducted according to the Bonferroni method. Results: The H. pylori infection rate was 11.2% in this Indonesian population. The DQB1*0401 genotype was noted to be associated with a high risk of H. pylori infection, compared with the DQB1*0301 genotype. None of the HLA-DQA1 or DQB1 haplotypes were related to the risk of H. pylori infection. Conclusions: The study suggests that HLADQB1 genes play important roles in H. pylori infection, but there was no statistically significant association between HLA-DQA1 or DQB1 haplotypes and H.pylori infection in our Lombok Indonesian population.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1065-1071
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• 2013

The swine leukocyte antigen class II molecules are possibly associated with the induction of protective immunity. The study described here was to investigate the relationship between polymorphisms in exon 2 of the swine DQA gene and piglet diarrhea. This study was carried out on 425 suckling piglets from three purebred pig strains (Large White, Landrace and Duroc). The genetic diversity of exon 2 in swine DQA was detected by PCR-SSCP and sequencing analysis, eight unique SSCP patterns (AB, BB, BC, CC, CD, BD, BE and DD) representing five specific allele (A to E) sequences were detected. Sequence analysis revealed 21 nucleotide variable sites and resulting in 12 amino acid substitutions in the populations. A moderate level polymorphism and significant deviations from Hardy-Weinberg equilibrium of the genotypes distribution were observed in the populations (p<0.01). The association analysis indicated that there was a statistically significant difference in the score of piglet diarrhea between different genotypes, individuals with genotype CC showed a lower diarrhea score than genotypes AB ($0.98{\pm}0.09$), BB ($0.85{\pm}0.77$) and BC ($1.25{\pm}0.23$) (p<0.05), and significantly low than genotype BE ($1.19{\pm}0.19$) (p<0.01), CC genotype may be a most resistance genotype for piglet diarrhea.

• Journal of Oral Medicine and Pain
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• v.19 no.2
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• pp.205-219
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• 1994

Cigarette butts from 5 smokers were gathered and then, placed in room temperature for 1, 3, 5, 7, 15 days. The possible use of the cigarette butts for individual identification was evaluated in sex determination, amplification of D1S80 locus, polymorphisms of HLA-DQA1 gene from the extracted DNA. 1. DNA extraction was possible in cigarette butts weree left in room temperature for 15days, so it can be applicatable to individual identification by polymerase chain reaction(PCR). 2. Amplification of X-Y homologous amelogenin gene by PCR made it possible to identify the sex in saliva stains (cigarette butts). 3. Amplification of D1S80 locus can be acquired from adding the boving serum albumin and hot start PCR procedures from forensic samples such as saliva stains (cigarette butts), so the AMP-FLPs examining is possible. 4. Genotype could be determined simply and rapidly using Amplitype$TM$ HLA-DQ$\alpha$ forensic kit in examining the HLA-DQA1 gene. From the investigation, DNA extraction, sex determination, amplification of D1S80 locus, polymorphisms of HLA-DQA1 gene was successfully done even though the cigarette butts were left for 15 days at room temperature. Therefore cigarette butts are highly reliable and applicatable as molecular biologic samples for individual identification.