• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.95-102
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• 2022

This study compares the difference between the remaining amount in syringes according to injection method and the dose of physiological saline when the radiopharmaceutical ¹⁸F-FDG isotope is injected into patients who visited the hospital for PET examination. After performing a CT or MRI using a contrast medium when ¹⁸F-FDG was injected into 40 patients who came to the hospital for PET examination without removing the 3-way, the radioactivity remaining in the syringe and the 3-way was measured and the dose of radioactivity confirmed. At this time, 20 patients were divided into different dose groups of physiological saline. Another injection method was used to compare the remaining amount of the syringe and the difference in the remaining amount according to the amount of physiological saline when the injection was performed with an extension. After an injection of ¹⁸F-FDG, the actual administered dose was confirmed by measuring the radioactivity remaining in the syringe and the 3-way or extension with a calibrator. As a result of measuring the radioactivity of the syringe before administering the radiopharmaceutical and the radioactivity of the syringe and the 3-way or extension after administration, the 3-way injection method in 10 cc's of physiological saline had the lowest residual amount. The remaining amount increased in the order of the extension to 10 cc's of saline and the 3-way to 5 cc's of saline. Likewise, the 5 cc's saline solution and the extension injection method demonstrated the highest residual amounts. The residual difference with the lowest level of remaining injection method was found to be 0.053 mCi. It was found that in a PET examination, by considering the radioactivity remaining in the 3-way and extension and by adjusting the dose of physiological saline, if the intended dose to be administered to the actual patient is determined, it is possible to administer the radiopharmaceutical to the patient more accurately.

• The Journal of Korean Society for Radiation Therapy
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• v.35
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• pp.7-13
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• 2023

Purpose: In this study, we evaluated the effect of using a customized bolus on dose delivery in the treatment plan when cervical cancer protruded out of the body along with the uterus and evaluated reproducibility in patient set-up. Materials & Methods: The treatment plan used the Eclipse Treatment Planning System (Version 15.5.0, Varian, USA) and the treatment machine was VitalBeam (Varian Medical Systems, USA). The radiotherapy technique used 6 MV energy in the AP/PA direction with 3D-CRT. The prescribed dose is 1.8 Gy/fx and the total dose is 50.4 Gy/28 fx. Semiflex TM31010 (PTW, Germany) was used as the ion chamber, and the dose distribution was analyzed and evaluated by comparing the planned and measured dose according to each position movement and the tumor center dose. The first measurement was performed at the center by applying a customized bolus to the phantom, and the measurement was performed while moving in the range of -2 cm to +2 cm in the X, Y, and Z directions from the center assuming a positional error. It was measured at intervals of 0.5 cm, the Y-axis direction was measured up to ±3 cm, and the situation in which Bolus was set-up incorrectly was also measured. The measured doses were compared based on doses corrected to CT Hounsfield Unit (HU) 240 of silicon instead of the phantom's air cavity. Result: The treatment dose distribution was uniform when the customized bolus was used, and there was no significant difference between the prescribed dose and the actual measured value even when positional errors occurred. It was confirmed that the existing sheet-type bolus is difficult to compensate for irregularly shaped tumors protruding outside the body, but customized Bolus is found to be useful in delivering treatment doses uniformly.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.642-649
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• 1999

Background: It is very important to determine an accurate staging of the non-small cell lung cancer(NSCLC) for an assessment of operability and it's prognosis. However, it is difficult to evaluate tumor involvement of mediastinal lymph nodes accurately utilizing noninvasive imaging modalities. PET is one of the sensitive and specific imaging modality. Unfortunately PET is limited use because of prohibitive cost involved with it's operation. Recently hybrid SPECT/PET(single photon emission computed tomography/positron emission tomography) camera based PET imaging was introduced with relatively low cost. We evaluated the usefulness of coincidence detection(CoDe) PET in the detection of metastasis to the mediastinal lymph nodes in patients with NSCLC. Methods: Twenty one patients with NSCLC were evaluated by CT or MRI and they were considered operable. CoDe PET was performed in all 21 patients prior to surgery. Tomographic slices of axial, coronal and sagittal planes were visually analysed. At surgery, mediastinal lymph nodes were removed and histological diagnosis was performed. CoDe PET findings were correlated with histological findings. Results: Twenty of 21 primary tumor masses were detected by the CoDe PET. Thirteen of 21 patients was correctly diagnosed mediastinal lymph node metastasis by the CoDe PET. Pathological N0 was 14 cases and the specificity of N0 of CoDe PET was 64.3%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of N1 node was 83.3%, 73.3%, 55.6%, 91.7%, and 76.2% respectively. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of N2 node was 60.0%, 87.5%, 60.0%,87.5%, and 90.0% respectively. There were 3 false negative cases but the size of the 3 nodes were less than 1cm. The size of true positive nodes were 1.1cm, 1.0cm, 0.5cm respectively. There were 1 false positive among the 12 lymph nodes which were larger than 1cm. False positive cases consisted of 1 tuberculosis case, 1 pneumoconiosis case and 1 anthracosis case. Conclusion: CoDe PET has relatively high negative predictive value in the enlarged lymph node in staging of mediastinal nodes in patients with NSCLC. Therefore CoDe PET is useful in ruling out metastasis of enlarged N3 nodes. However, further study is needed including more number of patients in the future.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.45-52
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• 2015

Purpose : The dose distribution of organ at risk (OAR) and normal tissue is affected by treatment technique in postoperative radiation therapy for prostate cancer. The aim of this study was to compare dose distribution characteristic and to evaluate treatment efficiency by devising VMAT plans according to applying differed number of arc and IMRT plan for postoperative patient of prostate cancer radiation therapy using a rectal balloon. Materials and Methods : Ten patients who received postoperative prostate radiation therapy in our hospital were compared. CT images of patients who inserted rectal balloon were acquired with 3 mm thickness and 10 MV energy of HD120MLC equipped Truebeam STx (Varian, Palo Alto, USA) was applied by using Eclipse (Version 11.0, Varian, Palo Alto, USA). 1 Arc, 2 Arc VMAT plans and 7-field IMRT plan were devised for each patient and same values were applied for dose volume constraint and plan normalization. To evaluate these plans, PTV coverage, conformity index (CI) and homogeneity index (HI) were compared and $R_{50%}$ was calculated to assess low dose spillage as per treatment plan. $D_{25%}$ of rectum and bladder Dmean were compared on OAR. And to evaluate the treatment efficiency, total monitor units(MU) and delivery time were considered. Each assessed result was analyzed by average value of 10 patients. Additionally, portal dosimetry was carried out for accuracy verification of beam delivery. Results : There was no significant difference on PTV coverage and HI among 3 plans. Especially CI and $R_{50%}$ on 7F-IMRT were the highest as 1.230, 3.991 respectively(p=0.00). Rectum $D_{25%}$ was similar between 1A-VMAT and 2A-VMAT. But approximately 7% higher value was observed on 7F-IMRT compare to the others(p=0.02) and bladder Dmean were similar among the all plan(P>0.05). Total MU were 494.7, 479.7, 757.9 respectively(P=0.00) for 1A-VMAT, 2A-VMAT, 7F-IMRT and at the most on 7F-IMRT. The delivery time were 65.2sec, 133.1sec, 145.5sec respectively(p=0.00). The obvious shortest time was observed on 1A-VMAT. All plans indicated over 99.5%(p=0.00) of gamma pass rate (2 mm, 2%) in portal dosimetry quality assurance. Conclusion : As a result of study, postoperative prostate cancer radiation therapy for patient using a rectal balloon, there was no significant difference of PTV coverage but 1A-VMAT and 2A-VMAT were more efficient for dose reduction of normal tissue and OARs. Between VMAT plans. $R_{50%}$ and MU were little lower in 2A-VMAT but 1A-VMAT has the shortest delivery time. So it is regarded to be an effective plan and it can reduce intra-fractional motion of patient also.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.49-63
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• 2018

Purpose : The purpose of this study is investigating the changes of treatment plan and comparing skin dose with or without the skin flash. To investigate optimal applications of the skin flash, the changes of skin dose of each plans by various thicknesses of skin flash were measured and analyzed also. Methods and Material : Anthropomorphic phantom was scanned by CT for this study. The 2 fields hybrid IMRT and the 6 fields static IMRT were generated from the Eclipse (ver. 13.7.16, Varian, USA) RTP system. Additional plans were generated from each IMRT plans by changing skin flash thickness to 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm and 2.5 cm. MU and maximum doses were measured also. The treatment equipment was 6MV of VitalBeam (Varian Medical System, USA). Measuring device was a metal oxide semiconductor field-effect transistor(MOSFET). Measuring points of skin doses are upper (1), middle (2) and lower (3) positions from center of the left breast of the phantom. Other points of skin doses, artificially moved to medial and lateral sides by 0.5 cm, were also measured. Results : The reference value of 2F-hIMRT was 206.7 cGy at 1, 186.7 cGy at 2, and 222 cGy at 3, and reference values of 6F-sIMRT were measured at 192 cGy at 1, 213 cGy at 2, and 215 cGy at 3. In comparison with these reference values, the first measurement point in 2F-hIMRT was 261.3 cGy with a skin flash 2.0 cm and 2.5 cm, and the highest dose difference was 26.1 %diff. and 5.6 %diff, respectively. The third measurement point was 245.3 cGy and 10.5 %diff at the skin flash 2.5 cm. In the 6F-sIMRT, the highest dose difference was observed at 216.3 cGy and 12.7 %diff. when applying the skin flash 2.0 cm for the first measurement point and the dose difference was the largest at the application point of 2.0 cm, not the skin flash 2.5 cm for each measurement point. In cases of medial 0.5 cm shift points of 2F-hIMRT and 6F-sIMRT without skin flash, the measured value was -75.2 %diff. and -70.1 %diff. at 2F, At -14.8, -12.5, and -21.0 %diff. at the 1st, 2nd and 3rd measurement points, respectively. Generally, both treatment plans showed an increase in total MU, maximum dose and %diff as skin flash thickness increased, except for some results. The difference of skin dose using 0.5 cm thickness of skin flash was lowest lesser than 20 % in every conditions. Conclusion : Minimizing the thickness of skin flash by 0.5 cm is considered most ideal because it makes it possible to keep down MUs and lowering maximum doses. In addition, It was found that MUs, maximum doses and differences of skin doses did not increase infinitely as skin flash thickness increase by. If the error margin caused by PTV or other factors is lesser than 1.0 cm, It is considered that there will be many advantages in with the skin flash technique comparing without it.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.225-230
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• 2009

Sex-sorting of sperm is an assisted reproductive technology (ART) used by the livestock industry for the mass production of animals of a desired sex. The standard method for sorting sperm is the detection of DNA content differences between X and Y chromosome-bearing sperm by flow cytometry. However, this method has variable efficiency and therefore requires verification by a second method. We have developed a sex determination method based on quantitative real-time polymerase chain reaction (qPCR) of the porcine amelogenin (AMEL) gene. The AMEL gene is present on both the X and the Y chromosome, but the length and sequence of its noncoding regions differ between the X and Y chromosomes. By measuring the threshold cycle (Ct) of qPCR, we were able to calculate the relative frequency of X chromosome. Two sets of AMEL primers were used in these studies. One set (AME) targeted AMEL gene sequences present in both X and Y chromosome, but produced PCR products of different lengths for each chromosome. The other set (AXR) bound to AMEL gene sequences present on the X chromosome but absent esholthe Y-chromosome. Relative product levels were calculated by normalizing the AXR fluorescence to the AME fluorescence. The AMEL method accurately predicted the sex ratios of boar sperm, demonstrating that it has potential value as a sex determination method.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8221-8224
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• 2014

Gastric cancer continues to be a leading cause of cancer death. The majority of patients with gastric adenocarcinoma in China present with advanced disease. Ruling out unresectable cancers from an unnecessary "open" exploration is very important. The aim of this study was to assess the value of five-port anatomical laparoscopic exploration in T4 gastric cancer in comparison with three-port laparoscopic exploration and laparotomy exploration. We conducted a retrospective study on 126 patients with T4 stage scheduled for D2 curative gastrectomy based on computed tomography (CT) staging at Department of Gastric Cancer and Soft Tissue Sarcoma, Fudan University Shanghai Cancer Center, from Apr. 2011 to Apr. 2013. Laparotomy exploration (Group I), three-port laparoscopic exploration (Group II) or five-port anatomical laparoscopic exploration (Group III) were performed prior to radical gastrectomy. Accuracy rate for feasibility of D2 curative gastrectomy in laparotomy exploration and five-port anatomical laparoscopic exploration groups was higher than that in the three-port laparoscopic exploration group. Five-port anatomical laparoscopic exploration group had the highest accuracy resection rate (Group I vs Group II vs Group III,92.6% vs78.6% vs 97.7%; p<0.05) and shorter length of hospitalization (Group I vs Group II vs Group III, $9.58{\pm}4.17$ vs $6.13{\pm}2.85$ vs $5.00{\pm}1.81$; p<0.001). Three-port laparoscopic exploration has low accuracy rate for assessing feasibility of D2 curative gastrectomy and five-port anatomical laparoscopic exploration should be performed on patients with T4 gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4437-4441
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• 2014

SMAD7 has been identified as a functional candidate gene for colorectal cancer (CRC). SMAD7 protein is a known antagonist of the transforming growth factor beta ($TGF-{\beta}$) signaling pathway which is involved in tumorigenesis. Polymorphisms in SMAD7 may thus alter cancer risk. The aim of this study was to investigate the influence of a SMAD7 gene polymorphism (rs2337107) on risk of CRC and clinicopathological features in an Iranian population. In total, 210 subjects including 105 patients with colorectal cancer and 105 healthy controls were recruited in our study. All samples were genotyped by TaqMan assay via an ABI 7500 Real Time PCR System (Applied Biosystems) with DNA from peripheral blood. The polymorphism was statistically analyzed to investigate the relationship with the risk of colorectal cancer and clinicopathological properties. Logistic regression analysis revealed that there was no significant association between rs2337107and the risk of colorectal cancer. In addition, no significant association between genotypes and clinicopathological features was observed (p value>0.05). Although there was not any association between genotypes and disorder, CT was the most common genotype in this population. This genotype prevalence was also higher in the patients with well grade (54.9%) and colon (72.0%) tumors. Our results provide the first evidence that this polymorphism is not a potential contributor to the risk of colorectal cancer and clinicopathological features in an Iranian population, and suggests the need of a large-scale case-control study to validate our results.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4637-4642
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• 2014

Background: Hypoxia-inducible factor $1{\alpha}$ (HIF-$1{\alpha}$) plays an important role in regulating cell survival and angiogenesis, which are critical for tumor growth and metastasis. Genetic variations of HIF1A have been shown to influence the susceptibility to many kinds of human tumors. Increased expression of HIF-$1{\alpha}$ has also been demonstrated to be involved in tumor progression. However, the prognostic value of single nucleotide polymorphisms (SNPs) inthe HIF1A gene remains to be determined in most cancer types, including colorectal cancer (CRC). In this study, we sought to investigate the predictive role of HIF1A SNPs in prognosis of CRC patients and efficacy of chemotherapy. Materials and Methods: We genotyped two functional SNPs in HIF1A gene using the Sequenom iPLEX genotyping system and then assessed their associations with clinicopathological parameters and clinical outcomes of 697 CRC patients receiving radical surgery using Cox logistic regression model and Kaplan Meier curves. Results: Generally, no significant association was found between these 2 SNPs and clinical outcomes of CRC. In stratified analysis of subgroup without adjuvant chemotherapy, patients carrying CT/TT genotypes of rs2057482 exhibited a borderline significant association with better overall survival when compared with those carrying CC genotype [Hazard ratio (HR), 0.47; 95% confidence interval (95% CI): 0.29-0.76; P < 0.01]. Moreover, significant protective effects on CRC outcomes conferred by adjuvant chemotherapy were exclusively observed in patients carrying CC genotype of rs2057482 and in those carrying AC/CC genotype of rs2301113. Conclusions: Genetic variations in HIF1A gene may modulate the efficacy of adjuvant chemotherapy after surgery in CRC patients.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3941-3944
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• 2013

Background: The use of preoperative chemoirradiation is the commonest treatment strategy employed in Malaysia for locally advanced rectal cancer. We need to determine the local control and survival rates for comparison with established rates in the literature. Materials and Methods: This retrospective study analyzed all newly diagnosed patients with rectal adenocarcinoma who underwent long course preoperative radiotherapy (RT) at the Department of Radiotherapy and Oncology, Kuala Lumpur Hospital (HKL) between $1^{st}$ January 2004 and $31^{st}$ December 2010. The aim of the study was to determine the radiological response post radiotherapy, pathological response including circumferential resection margin (CRM) status, 3 years local control, 3 years overall survival (OS) and 3 years disease free survival (DFS). Statistical analysis was performed using the SPSS software. Kaplan-Meier and log rank analysis were used to determine survival outcomes. Results: A total of 507 patients with rectal cancer underwent RT at HKL. Sixty seven who underwent long course preoperative RT were eligible for this study. The median age at diagnosis was 60 years old with a range of 26-78 years. The median tumour location was 6 cm from the anal verge. Most patients had suspicion of mesorectum involvement (95.5%) while 28.4% of patients had enlarged pelvic nodes on staging CT scan. All patients underwent preoperative chemo-irradiation except for five who had preoperative RT alone. Only 38 patients underwent definitive surgery (56.7%). Five patients were deemed to be inoperable radiologically and 3 patients were found to have unresectable disease intraoperatively. The remaining 21 patients defaulted surgery (31.3%). The median time from completion of RT to surgery was 8 weeks (range 5.6 to 29.4 weeks). Fifteen patients (39.5%) had surgery more than 8 weeks after completion of RT. Complete pathological response was noted in 4 patients (10.5%). The pathological CRM positive rate after RT was 18.4%. With a median follow-up of 38.8 months, the 3 year local control rate was 67%. The 3 years rate for CRM positive (<2 mm), CRM clear (>2 mm) and pCR groups were 0%, 88.1% and 100% respectively (p-value of 0.007). The 3 year OS and DFS were 57.3% and 44.8% respectively. Conclusions: In conclusion, the approach of long course preoperative chemoirradiation for rectal cancer needs to be re-examined in our local setting. The high rate of local recurrence is worrying and is mainly due to patient defaulting post-preoperative chemoirradiation or delayed definitive surgery.