1.Three-dimensional dose reconstruction-based pretreatment dosimetric verification in volumetric modulated arc therapy for prostate cancer
Yuri JEONG ; Jeong Geun OH ; Jeong Ku KANG ; Sun Rock MOON ; Kang Kyoo LEE
Radiation Oncology Journal 2020;38(1):60-67
Purpose:
We performed three-dimensional (3D) dose reconstruction-based pretreatment verification to evaluate gamma analysis acceptance criteria in volumetric modulated arc therapy (VMAT) for prostate cancer.
Materials and Methods:
Pretreatment verification for 28 VMAT plans for prostate cancer was performed using the COMPASS system with a dolphin detector. The 3D reconstructed dose distribution of the treatment planning system calculation (TC) was compared with that of COMPASS independent calculation (CC) and COMPASS reconstruction from the dolphin detector measurement (CR). Gamma results (gamma failure rate and average gamma value [GFR and γAvg]) and dose-volume histogram (DVH) deviations, 98%, 2% and mean dose-volume difference (DD98%, DD2% and DDmean), were evaluated. Gamma analyses were performed with two acceptance criteria, 2%/2 mm and 3%/3 mm.
Results:
The GFR in 2%/2 mm criteria were less than 8%, and those in 3%/3 mm criteria were less than 1% for all structures in comparisons between TC, CC, and CR. In the comparison between TC and CR, GFR and γAvg in 2%/2 mm criteria were significantly higher than those in 3%/3 mm criteria. The DVH deviations were within 2%, except for DDmean (%) for rectum and bladder.
Conclusions
The 3%/3 mm criteria were not strict enough to identify any discrepancies between planned and measured doses, and DVH deviations were less than 2% in most parameters. Therefore, gamma criteria of 2%/2 mm and DVH related parameters could be a useful tool for pretreatment verification for VMAT in prostate cancer.
2.Multi-institutional analysis of T3 subtypes and adjuvant radiotherapy effects in resected T3N0 non-small cell lung cancer patients.
Yunseon CHOI ; Ik Jae LEE ; Chang Young LEE ; Jae Ho CHO ; Won Hoon CHOI ; Hong In YOON ; Yun Han LEE ; Chang Geol LEE ; Ki Chang KEUM ; Kyung Young CHUNG ; Seok Jin HAAM ; Hyo Chae PAIK ; Kang Kyoo LEE ; Sun Rock MOON ; Jong Young LEE ; Kyung Ran PARK ; Young Suk KIM
Radiation Oncology Journal 2015;33(2):75-82
PURPOSE: We evaluated the prognostic significance of T3 subtypes and the role of adjuvant radiotherapy in patients with resected the American Joint Committee on Cancer stage IIB T3N0M0 non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: T3N0 NSCLC patients who underwent resection from January 1990 to October 2009 (n = 102) were enrolled and categorized into 6 subgroups according to the extent of invasion: parietal pleura chest wall invasion, mediastinal pleural invasion, diaphragm invasion, separated tumor nodules in the same lobe, endobronchial tumor <2 cm distal to the carina, and tumor-associated collapse. RESULTS: The median overall survival (OS) and disease-free survival (DFS) were 55.3 months and 51.2 months, respectively. In postoperative T3N0M0 patients, the tumor size was a significant prognostic factor for survival (OS, p = 0.035 and DFS, p = 0.035, respectively). Patients with endobronchial tumors within 2 cm of the carina also showed better OS and DFS than those in the other T3 subtypes (p = 0.018 and p = 0.016, respectively). However, adjuvant radiotherapy did not cause any improvement in survival (OS, p = 0.518 and DFS, p = 0.463, respectively). Only patients with mediastinal pleural invasion (n = 25) demonstrated improved OS and DFS after adjuvant radiotherapy (n = 18) (p = 0.012 and p = 0.040, respectively). CONCLUSION: The T3N0 NSCLC subtype that showed the most favorable prognosis is the one with endobronchial tumors within 2 cm of the carina. Adjuvant radiotherapy is not effective in improving survival outcome in resected T3N0 NSCLC.
Carcinoma, Non-Small-Cell Lung*
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Diaphragm
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Disease-Free Survival
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Humans
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Joints
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Pleura
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Prognosis
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Radiotherapy, Adjuvant*
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Thoracic Wall
3.Comparison of New and Established Full-Field Digital Mammography Systems in Diagnostic Performance.
Eun Sook KO ; Boo Kyung HAN ; Sun Mi KIM ; Eun Young KO ; Mijung JANG ; Chae Yeon LYOU ; Jung Min CHANG ; Woo Kyung MOON ; Rock Bum KIM
Korean Journal of Radiology 2013;14(2):164-170
OBJECTIVE: To compare the diagnostic performance of new and established full-field digital mammography (FFDM) systems. MATERIALS AND METHODS: During a 15-month period, 1038 asymptomatic women who visited for mammography were prospectively included from two institutions. For women with routine two-view mammograms from established FFDM systems, bilateral mediolateral oblique (MLO) mammograms were repeated using the new FFDM system. One of the four reviewers evaluated two-sets of bilateral MLO mammograms at 4-week intervals by using a five-point score for the probability of malignancy according to a Breast Imaging Reporting and Data System. The lesion type and breast density were determined by the consensus of two readers at each institution. The dichotomized mammographic results correlated with a final pathologic outcome and follow-up data. Receiver operating characteristic (ROC) curves, sensitivity, and specificity were compared in general and according to the lesion type and breast density. RESULTS: Of the 1038 cases, 193 (18.6%) had cancer. The areas under the ROC curve (AUC), sensitivity, and specificity of the established system were 0.815, 65.3%, and 90.2%, respectively. Those of the new system were 0.839, 68.4%, and 91.7%, respectively. There were no significant differences in the AUCs, sensitivities or the specificities in general between new and established systems (Ps = 0.194, 0.590, 0.322, respectively). We found no significant difference in these parameters according to lesion type or breast density. CONCLUSION: The new FFDM system has a comparable diagnostic performance with established systems.
Adult
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Aged
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Area Under Curve
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Breast Neoplasms/pathology/*radiography
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Female
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Humans
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Mammography/*methods
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Middle Aged
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Prospective Studies
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ROC Curve
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Radiographic Image Enhancement/*methods
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Republic of Korea
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Sensitivity and Specificity
4.The Effect of Autophagy to Cell Death in Nutrient-Deprived H460 Cells.
Hye Yeon JANG ; Hyang Jeong JO ; Ki Eun HWHANG ; So Young KIM ; Kang Kyoo LEE ; Sun Rock MOON ; Jeong Hyun SHIN ; Kyung Hwa CHO ; Mi Kung LEE ; Sam Youn LEE ; Soon Ah PARK ; Jong Kun PARK ; Hui Jung KIM ; Sei Hoon YANG
Tuberculosis and Respiratory Diseases 2010;69(2):81-94
BACKGROUND: Autophagy is an important adaptive mechanism in normal development and in response to changing environmental stimuli in cancer. Previous papers have reported that different types of cancer underwent autophagy to obtain amino acids as energy source of dying cells in nutrient-deprived conditions. However, whether or not autophagy in the process of lung cancer causes death or survival is controversial. Therefore in this study, we investigated whether nutrient deprivation induces autophagy in human H460 lung cancer cells. METHODS: H460, lung cancer cells were incubated in RPMI 1640 medium, and the starved media, which are BME and RPMI media without serum, including 2-deoxyl-D-glucose according to time dependence. To evaluate the viability and find out the mechanism of cell death under nutrient-deprived conditions, the MTT assay and flow cytometry were done and analyzed the apoptotic and autophagic related proteins. It is also measured the development of acidic vascular organelles by acridine orange. RESULTS: The nutrient-deprived cancer cell is relatively sensitive to cell death rather than normal nutrition. Massive cytoplasmic vacuolization was seen under nutrient-deprived conditions. Autophagic vacuoles were visible at approximately 12 h and as time ran out, vacuoles became larger and denser with the increasing number of vacuoles. In addition, the proportion of acridine orange stain-positive cells increased according to time dependence. Localization of GFP-LC3 in cytoplasm and expression of LC-3II and Beclin 1 were increased according to time dependence on nutrient-deprived cells. CONCLUSION: Nutrient deprivation induces cell death through autophagy in H460 lung cancer cells.
Acridine Orange
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Amino Acids
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Autophagy
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Cell Death
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Cytoplasm
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Flow Cytometry
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Humans
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Lung Neoplasms
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Malnutrition
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Organelles
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Proteins
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Vacuoles
5.Induction of Autophagy by Low Dose of Cisplatin in H460 Lung Cancer Cells.
Jeong Hyun SHIN ; Hye Yeon JANG ; Jin Soo CHUNG ; Kyung Hwa CHO ; Ki Eun HWANG ; So Young KIM ; Hui Jung KIM ; Sam Youn LEE ; Mi Kung LEE ; Soon Ah PARK ; Sun Rock MOON ; Kang Kyu LEE ; Hyang Jeong JO ; Sei Hoon YANG
Tuberculosis and Respiratory Diseases 2010;69(1):16-23
BACKGROUND: Most lung cancer patients receive systemic chemotherapy at an advanced stage disease. Cisplatin-based chemotherapy is the main regimen for treating advanced lung cancer. Recently, autophagy has become an important mechanism of cellular adaptation under starvation or cell oxidative stress. The purpose of this study was to determine whether or not autophagy can occurred in cisplatin-treated lung cancer cells. METHODS: H460 cells were incubated with RPMI 1640 and treated in 5 micrometer or 20 micrometer cisplatin concentrations at specific time intervals. Cells surviving cisplatin treatment were measured and compared using an MTT cell viability assay to cells that underwent apoptosis with autophagy by nuclear staining, apoptotic or autophagic related proteins, and autophagic vacuoles. The development of acidic vascular organelles was using acridine orange staining and fluorescent expression of GFP-LC3 protein in its transfected cells was observed to evaluate autophagy. RESULTS: Lung cancer cells treated with 5 micrometer cisplatin-treated were less sensitive to cell death than 20 micrometer cisplatin-treated cells in a time-dependent manner. Nuclear fragmentation at 5 micrometer was not detected, even though it was discovered at 20 micrometer. Poly (ADP-ribose) polymerase cleavages were not detected in 5 micrometer within 24 hours. Massive vacuolization in the cytoplasm of 5 micrometer treated cells were observed. Acridine orange stain-positive cells was increased according in time-dependence manner. The autophagosome-incorporated LC3 II protein expression was increased in 5 micrometer treated cells, but was not detected in 20 micrometer treated cells. The expression of GFP-LC3 were increased in 5 micrometer treated cells in a time-dependent manner. CONCLUSION: The induction of autophagy occurred in 5 micrometer dose of cisplatin-treated lung cancer cells.
Acridine Orange
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Apoptosis
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Autophagy
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Cell Death
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Cell Survival
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Cisplatin
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Cytoplasm
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Humans
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Lung
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Lung Neoplasms
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Organelles
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Oxidative Stress
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Proteins
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Starvation
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Vacuoles
6.Induction of Autophagy by Low Dose of Cisplatin in H460 Lung Cancer Cells.
Jeong Hyun SHIN ; Hye Yeon JANG ; Jin Soo CHUNG ; Kyung Hwa CHO ; Ki Eun HWANG ; So Young KIM ; Hui Jung KIM ; Sam Youn LEE ; Mi Kung LEE ; Soon Ah PARK ; Sun Rock MOON ; Kang Kyu LEE ; Hyang Jeong JO ; Sei Hoon YANG
Tuberculosis and Respiratory Diseases 2010;69(1):16-23
BACKGROUND: Most lung cancer patients receive systemic chemotherapy at an advanced stage disease. Cisplatin-based chemotherapy is the main regimen for treating advanced lung cancer. Recently, autophagy has become an important mechanism of cellular adaptation under starvation or cell oxidative stress. The purpose of this study was to determine whether or not autophagy can occurred in cisplatin-treated lung cancer cells. METHODS: H460 cells were incubated with RPMI 1640 and treated in 5 micrometer or 20 micrometer cisplatin concentrations at specific time intervals. Cells surviving cisplatin treatment were measured and compared using an MTT cell viability assay to cells that underwent apoptosis with autophagy by nuclear staining, apoptotic or autophagic related proteins, and autophagic vacuoles. The development of acidic vascular organelles was using acridine orange staining and fluorescent expression of GFP-LC3 protein in its transfected cells was observed to evaluate autophagy. RESULTS: Lung cancer cells treated with 5 micrometer cisplatin-treated were less sensitive to cell death than 20 micrometer cisplatin-treated cells in a time-dependent manner. Nuclear fragmentation at 5 micrometer was not detected, even though it was discovered at 20 micrometer. Poly (ADP-ribose) polymerase cleavages were not detected in 5 micrometer within 24 hours. Massive vacuolization in the cytoplasm of 5 micrometer treated cells were observed. Acridine orange stain-positive cells was increased according in time-dependence manner. The autophagosome-incorporated LC3 II protein expression was increased in 5 micrometer treated cells, but was not detected in 20 micrometer treated cells. The expression of GFP-LC3 were increased in 5 micrometer treated cells in a time-dependent manner. CONCLUSION: The induction of autophagy occurred in 5 micrometer dose of cisplatin-treated lung cancer cells.
Acridine Orange
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Apoptosis
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Autophagy
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Cell Death
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Cell Survival
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Cisplatin
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Cytoplasm
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Humans
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Lung
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Lung Neoplasms
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Organelles
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Oxidative Stress
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Proteins
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Starvation
;
Vacuoles
7.Study on the Compatibility for an Ir-192 Source Manufactured by Korea Atomic Energy Research Institute (KAERI) in GammaMed Brachytherapy Machine.
Dong Hyeok JEONG ; Kang Kyoo LEE ; Soo Kon KIM ; Sun Rock MOON
Korean Journal of Medical Physics 2010;21(1):78-85
The compatibility with GammaMed-12i brachytherapy machine for an Ir-192 encapsulated source (IRRS20, KAERI, Korea) manufactured by Korea atomic energy research institute (KAERI) has been investigated. As a mechanical testing of compatibility, precise measurement of step movement with channels, measurement of curvature of radius for wire, and emergency return testing were performed. Periodic measurements of air kerma strength for 45 days were carried out to evaluate decay characteristics of Ir-192 radioisotope and comparison of dose distributions in phantom between KAERI and old sources previously used were performed by film dosimetry. KAERI source has a good compatibility with GammaMed12i machine as a result of mechanical testing. There are in good agreement with calculated values in activity characteristics and there were small differences in dose distributions around the source in comparison between KAERI and old source.
Academies and Institutes
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Brachytherapy
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Emergencies
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Film Dosimetry
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Korea
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Nuclear Energy
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Radius
8.Commissioning of a micro-MLC (mMLC) for Stereotactic Radiosurgery.
Dong Hyeok JEONG ; Kyo Chul SHIN ; Jeung Kee KIM ; Soo Kon KIM ; Sun Rock MOON ; Kang Kyoo LEE
Korean Journal of Medical Physics 2009;20(1):43-50
The 4 bank mico-MLC (mMLC; Acculeaf, Direx, Isral) has been commissioned for clinical use of linac based stereotactic radiosurgery. The geometrical parameters to control the leaves were determined and comparisons between measured and calculated by the calculation model were performed in terms of absolute dose (cGy/100 MU). As a result of evaluating calculated dose for various field sizes and depths of 5 and 10 cm in water in the geometric condition of fixed SSD (source to surface distance) and fixed SCD (source to chamber distance), most of differences were within 1% for 6 MV and 15 MV x-rays. The penumbral widths at the isocenter were approximately evaluated to 0.29~0.43 cm depending on the field size for 6 MV and 0.36~0.51 cm for 15 MV x-rays. The average transmission and leakage for 6 MV and 15 MV x-rays were 6.6% and 7.4% respectively in single level of leaves fully closed. In case of dual level of leaves fully closed the measured transmission is approximately 0.5% for both 6 MV and 15 MV x-rays. Through the commissiong procedure we could verify the dose characteristics of mMLC and approximately evaluate the error ranges for treatment planning system.
Radiosurgery
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Silver Sulfadiazine
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Water
9.Quality Correction for Ir-192 Gamma Rays in Air Kerma Strength Dosimetry Using Cylindrical Ionization Chambers.
Dong Hyeok JEONG ; Jhin Kee KIM ; Ki Hwan KIM ; Young Kee OH ; Soo Kon KIM ; Kang Kyoo LEE ; Sun Rock MOON
Korean Journal of Medical Physics 2009;20(1):30-36
The quality correction in the air kerma dosimetry for Ir-192 using farmer type ionization chambers calibrated by Co-60 quality is required. In this study we determined quality factor (kappa u) of two ionization chambers of PTW-N30001 and N23333 for Ir-192 source using dosimetric method. The quality factors for energy spectrum of microSelectron were determined as kappa u=1.016 and 1.017 for PTW-N30001 and N23333 ionization chambers respectively. We applied quality factors in air kerma dosimetry for microSelectron source and compared with reference values. As a results we found that the differences between reference air kerma rate and measured it with and without quality correction were about -0.5% and -2.0% respectively.
Gamma Rays
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Reference Values
10.Accuracy Evaluation of Treatment Planning System Using Irregular-surface Water Phantom.
Dong Hyeok JEONG ; Ki Hwan KIM ; Kang Kyoo LEE ; Sun Rock MOON ; Jhin Kee KIM ; Kyo Chul SHIN ; Young Kee OH ; Jeung Kee KIM ; Moon June CHO ; Jun Sang KIM
Korean Journal of Medical Physics 2008;19(2):131-138
We evaluated on the calculation accuracy of treatment planning system (TPS) with phantom having convex and concave surface. The TPS is Eclipse (Varian, USA) using both algorithms AAA and PBC for photon dose calculations. PBC algorithms have three corrections of Batho, modified Batho (M-Batho), and equivalent TAR (E-TAR). The field sizes were 10x10 cm2 and 20x20 cm2, and MLC-shaped fields for these fields. We measured doses at three depths 5, 10 and 15 cm in phantom of SSD=90 cm in the condition of inserted farmer chamber. For given conditions, we have calculated dose with these algorithms and compared them with measured doses. In AAA the calculated doses (dose/MU) were agreed to measured doses within +/-1% in flat and convex surface and were under estimated with -1.9% maximum in concave surface. In PBC the calculated doses were over estimated with +1.7% and +4.1% respectively in flat and convex surface and the differences were from -3.1% to +2.1% in concave surface. In comparison of criteria from AAPM and IAEA reports, and statistical analysis for these results, it is found that the AAA's results are in good agreement with measured values and the M-Batho's results are generally good agreed with measured values among PBC algorithms.
Water

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