• Radiation Oncology Journal
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• 제35권2호
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• pp.144-152
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• 2017

Purpose: The role of radiotherapy (RT) was largely deserted after the introduction of platinum-based chemotherapy, but still survival rates are disappointingly low. This study focuses on assessing the clinical efficacy of RT in relation to chemotherapy resistance. Materials and Methods: From October 2002 to January 2015, 44 patients were diagnosed with epithelial ovarian cancer (EOC) and treated with palliative RT for persistent or recurrent EOC. All patients received initial treatment with optimal debulking surgery and adjuvant platinum-based chemotherapy. The biologically effective dose (BED) was calculated with ${\alpha}/{\beta}$ set at 10. Ninety-four sites were treated with RT with a median BED of 50.7 Gy (range 28.0 to 79.2 Gy). The primary end-point was the in-field local control (LC) interval, defined as the time interval from the date RT was completed to the date any progressive or newly recurring disease within the RT field was detected on radiographic imaging. Results: The median follow-up duration was 52.3 months (range 7.7 to 179.0 months). The 1-year and 2-year in-field LC rates were 66.0% and 55.0%, respectively. Comparisons of percent change of in-field tumor response showed similar distribution of responses among chemoresistant and chemosensitive tumors. On multivariate analysis of predictive factors for in-field LC analyzed by sites treated, $BED{\geq}50Gy$ (hazard ratio, 0.4; confidence interval, 0.2-0.9; p = 0.025) showed better outcomes. Conclusion: Regardless of resistance to platinum-based chemotherapy, RT can be a feasible treatment modality for patients with persistent of recurrent EOC. The specific role of RT using updated approaches needs to be reassessed.

• Journal of the Korean Data and Information Science Society
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• 제25권2호
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• pp.327-336
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• 2014

재발 사건 자료란 연구대상이 같은 종류의 사건을 반복적으로 경험할 때 발생하는 자료이다. 이러한 재발 사건은 사회과학, 자연과학, 공학, 의약학 등 다양한 분야에서 나타날 수 있다. 재발 사건자료를 분석할 때 연구자의 관심에 따라 사건 발생시간이나 사건 발생간의 소요시간을 이용하여 분석할 수 있다. 이 논문에서는 사건 발생시점간의 소요시간을 이용하여 불완전한 관측을 가진 재발 사건자료를 분석하고자 한다. 이 자료의 특징은 일부 관측대상들이 일정기간 동안 연구에서 제외되는 관측틈을 갖는다는 것이다. 이 때 관측틈은 불완전한 형태로 나타나게 되는데 그 이유는 관측틈의 시작시점은 알고 있지만 종료시점은 알 수 없기 때문이다. 이러한 미지의 종료시점을 추정하기 위해서 구간 중도 절단 방법이 적용된다. 따라서 종료시점이 추정된 후 프레일티를 포함한 회귀모형을 적용하여 공변량이 사건 재발에 미치는 영향을 알아볼 수 있다. 또한 제안한 방법을 실제자료에 적용하여 관측틈을 고려한 경우와 고려하지 않은 경우를 비교하고자 한다.

• Korean Journal of Radiology
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• 제25권3호
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• pp.277-288
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• 2024

Objective: We previously found that the incidence of sarcopenia increased with declining glucose metabolism of muscle in patients with treatment-naïve diffuse large B-cell lymphoma (DLBCL). This study aimed to investigate the relationship between sarcopenia and muscle glucometabolism using ¹⁸F-FDG PET/CT at baseline and end-of-treatment, analyze the changes in these parameters through treatment, and assess their prognostic values. Materials and Methods: The records of 103 patients with DLBCL (median 54 years [range, 21-76]; male:female, 50:53) were retrospectively reviewed. Skeletal muscle area at the third lumbar vertebral (L3) level was measured, and skeletal muscle index (SMI) was calculated to determine sarcopenia, defined as SMI < 44.77 cm²/m² and < 32.50 cm²/m² for male and female, respectively. Glucometabolic parameters of the psoas major muscle, including maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmean), were measured at L3 as well. Their changes across treatment were also calculated as ΔSMI, ΔSUVmax, and ΔSUVmean; Δbody mass index was also calculated. Associations between SMI and the metabolic parameters were analyzed, and their associations with progression-free survival (PFS) and overall survival (OS) were identified. Results: The incidence of sarcopenia was 29.1% and 36.9% before and after treatment, respectively. SMI (P = 0.004) was lower, and sarcopenia was more frequent (P = 0.011) at end-of-treatment than at baseline. The SUVmax and SUVmean of muscle were lower (P < 0.001) in sarcopenia than in non-sarcopenia at both baseline and end-of-treatment. ΔSMI was positively correlated with ΔSUVmax of muscle (P = 0.022). Multivariable Cox regression analysis showed that sarcopenia at end-of-treatment was independently negatively associated with PFS (adjusted hazard ratio [95% confidence interval], 2.469 [1.022-5.965]), while sarcopenia at baseline was independently negatively associated with OS (5.051 [1.453-17.562]). Conclusion: Sarcopenic patients had lower muscle glucometabolism, and the muscular and metabolic changes across treatment were positively correlated. Sarcopenia at baseline and end-of-treatment was negatively associated with the prognosis of DLBCL.

• Korean Journal of Radiology
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• 제23권11호
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• pp.1055-1066
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• 2022

Objective: The clinical relevance of myosteatosis has not been well evaluated in patients with pancreatic ductal adenocarcinoma (PDAC), although sarcopenia has been extensively researched. Therefore, we evaluated the prognostic value of muscle quality, including myosteatosis, in patients with resectable PDAC treated surgically. Materials and Methods: We retrospectively evaluated 347 patients with resectable PDAC who underwent curative surgery (mean age ± standard deviation, 63.6 ± 9.6 years; 202 male). Automatic muscle segmentation was performed on preoperative computed tomography (CT) images using an artificial intelligence program. A single axial image of the portal phase at the inferior endplate level of the L3 vertebra was used for analysis in each patient. Sarcopenia was evaluated using the skeletal muscle index, calculated as the skeletal muscle area (SMA) divided by the height squared. The mean SMA attenuation was used to evaluate myosteatosis. Diagnostic cutoff values for sarcopenia and myosteatosis were devised using the Contal and O'Quigley methods, and patients were classified according to normal (nMT), sarcopenic (sMT), myosteatotic (mMT), or combined (cMT) muscle quality types. Multivariable Cox regression analyses were conducted to assess the effects of muscle type on the overall survival (OS) and recurrence-free survival (RFS) after surgery. Results: Eighty-four (24.2%), 73 (21.0%), 75 (21.6%), and 115 (33.1%) patients were classified as having nMT, sMT, mMT, and cMT, respectively. Compared to nMT, mMT and cMT were significantly associated with poorer OS, with hazard ratios (HRs) of 1.49 (95% confidence interval, 1.00-2.22) and 1.68 (1.16-2.43), respectively, while sMT was not (HR of 1.40 [0.94-2.10]). Only mMT was significantly associated with poorer RFS, with an HR of 1.59 (1.07-2.35), while sMT and cMT were not. Conclusion: Myosteatosis was associated with poor OS and RFS in patients with resectable PDAC who underwent curative surgery.

• Radiation Oncology Journal
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• 제1권1호
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• pp.95-102
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• 1983

The radical treatment of uterine cervical cancer by interacavitary radium or cesium, in combination with teletherapy are well known. Although the result of such treatment should not give rise to complacency, problem of radiation exposure to medical staff had not been resolved. Fortunately, many attempts have been made to reduce this hazard, most of which take the form of afterloading applicators with a suitably shielded radioisotope. In order to avoid hazardous radiation exposure to staffs concerned with brachytherapy, RALS using high intensity source of Co-60, have been employed at Yonsei Cancer Center since May, 1979. It allows rectal and bladder doses to be kept low, while maintaining a satifactory usual dose distribution of the other type of applicators, and the short treatment time allow four or five patients to be treated per hour. It also removes much patient's discomfort and the difficulties of nursing these patients. Since the first introduction in Korea, over seven hundred cases with various stage of uterine cervical cancer have been treated on a radical basis at this center last 4 years. These authors have strongly attracted attention to the results in terms of local control rate, survival s and morbidity compared with those of conventional low dose rate radiotherapy. Retrospective interim analysis of data was preliminarily accomplished through the labored follow-up study of 340 cases treated during initial 2 years and the radiobiologic standpoint of high dose rate intracavitary irradiation will be discussed.

• Tuberculosis and Respiratory Diseases
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• 제85권2호
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• pp.195-201
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• 2022

Background: The aim of this study was to evaluate the long-term (5-year) clinical outcomes of patients who received intensive care unit (ICU) treatment using Korean nationwide data. Methods: All patients aged >18 years with ICU admission according to Korean claims data from January 2008 to December 2010 were enrolled. These enrolled patients were followed up until December 2015. The primary outcome was ICU mortality. Results: Among all critically ill patients admitted to the ICU (n=323,765), patients with cancer showed higher ICU mortality (18.6%) than those without cancer (13.2%, p<0.001). However, there was no significant difference in ICU mortality at day 28 among patients without cancer (14.5%) and those with cancer (lung cancer or hematologic malignancies) (14.3%). Compared to patients without cancer, hazard ratios of those with cancer for ICU mortality at 5 years were: 1.90 (1.87-1.94) for lung cancer; 1.44 (1.43-1.46) for other solid cancers; and 3.05 (2.95-3.16) for hematologic malignancies. Conclusion: This study showed that the long-term survival rate of patients with cancer was significantly worse than that of general critically ill patients. However, short term outcomes of critically ill patients with cancer were not significantly different from those of general patients, except for those with lung cancer or hematologic malignancies.

• Journal of Gastric Cancer
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• 제18권2호
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• pp.142-151
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• 2018

Purpose: The modification of the cancer classification system aimed to improve the classical anatomy-based tumor, node, metastasis (TNM) staging by considering tumor biology, which is associated with patient prognosis, because such information provides additional precision and flexibility. Materials and Methods: We previously developed an mRNA expression-based single patient classifier (SPC) algorithm that could predict the prognosis of patients with stage II/III gastric cancer. We also validated its utilization in clinical settings. The prognostic single patient classifier (pSPC) differentiates based on 3 prognostic groups (low-, intermediate-, and high-risk), and these groups were considered as independent prognostic factors along with TNM stages. We evaluated whether the modified TNM staging system based on the pSPC has a better prognostic performance than the TNM 8th edition staging system. The data of 652 patients who underwent gastrectomy with curative intent for gastric cancer between 2000 and 2004 were evaluated. Furthermore, 2 other cohorts (n=307 and 625) from a previous study were assessed. Thus, 1,584 patients were included in the analysis. To modify the TNM staging system, one-grade down-staging was applied to low-risk patients according to the pSPC in the TNM 8th edition staging system; for intermediate- and high-risk groups, the modified TNM and TNM 8th edition staging systems were identical. Results: Among the 1,584 patients, 187 (11.8%), 664 (41.9%), and 733 (46.3%) were classified into the low-, intermediate-, and high-risk groups, respectively, according to the pSPC. pSPC prognoses and survival curves of the overall population were well stratified, and the TNM stage-adjusted hazard ratios of the intermediate- and high-risk groups were 1.96 (95% confidence interval [CI], 1.41-2.72; P<0.001) and 2.54 (95% CI, 1.84-3.50; P<0.001), respectively. Using Harrell's C-index, the prognostic performance of the modified TNM system was evaluated, and the results showed that its prognostic performance was better than that of the TNM 8th edition staging system in terms of overall survival (0.635 vs. 0.620, P<0.001). Conclusions: The pSPC-modified TNM staging is an alternative staging system for stage II/III gastric cancer.

• 대한이식학회지
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• 제31권4호
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• pp.200-206
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• 2017

Background: Risk factors for bone avascular necrosis (AVN), a common late complication after kidney transplantation (KT), are not well known. Methods: Patients that underwent living-donor KT at Asan Medical Center between January 2009 and July 2016 were included in this retrospective study to determine the incidence and risk factors for AVN after KT. Results: Among 1,570 patients that underwent living-donor KT, 33 (2.1%) developed AVN during a mean follow-up of 49.8±25.0 months. Additionally, AVN was diagnosed at a mean of 13.9±6.6 months after KT. The mean cumulative corticosteroid dose during the last follow-up in patients without AVN (9,108±3,400 mg) was higher than that that in patients with AVN (4,483±1,114 mg) until AVN development (P<0.01). More patients among those with AVN (n=4, 12.1%) underwent steroid pulse treatment because of biopsy-proven rejections during the first 6 months after KT than patients without AVN (n=68, 4.4%; P=0.04). Female (hazard ratio [HR], 2.29; P=0.04) and steroid pulse treatment during the first 6 months (HR, 2.31; P=0.02) were significant AVN risk factors as revealed by the Cox proportional multivariate analysis. However, no significant differences in rejection-free graft survival rates were observed between the two groups (P=0.67). Conclusions: Steroid pulse treatment within 6 months of KT and being female were independent risk factors for AVN development.

• Journal of Gastric Cancer
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• 제20권2호
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• pp.190-201
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• 2020

Purpose: This study sought to investigate the prognostic significance of tumor-infiltrating lymphocytes (TILs) in relation to tumor location within the stomach. Materials and Methods: The densities and prognostic significance of TIL subsets were evaluated in 542 gastric cancer patients who underwent gastrectomy. Immunohistochemical staining for CD3, CD4, CD8, forkhead/winged helix transcription factor (Foxp3), and granzyme B was performed. Results: Cardia cancer was associated with significantly lower densities of CD8 T-cells and higher densities of Foxp3 and granzyme B T-cells than non-cardia tumors. Multivariate analysis showed that advanced age (hazard ratio [HR], 1.023; 95% confidence interval [CI], 1.006-1.040), advanced T classification (HR, 2.029; 95% CI, 1.106-3.721), lymph node metastasis (HR, 3.319; 95% CI, 1.947-5.658), low CD3 expression (HR, 0.997; 95% CI, 0.994-0.999), and a high Foxp3/CD4 ratio (HR, 1.007; 95% CI, 1.001-1.012) were independent predictors of poor overall survival in cardia cancer patients. In non-cardia cancer patients, total gastrectomy (HR, 2.147; 95% CI, 1.507-3.059), advanced T classification (HR, 2.158; 95% CI, 1.425-3.266), lymph node metastasis (HR, 1.854; 95% CI, 1.250-2.750), and a low Foxp3/CD4 ratio (HR, 0.978; 95% CI, 0.959-0.997) were poor prognostic factors for survival. Conclusions: The densities and prognostic effects of TILs differed in relation to the location of tumors within the stomach. The contrasting prognostic effects of Foxp3/CD4 ratio in cardia and non-cardia gastric cancer patients suggests that clinicians ought to consider tumor location when determining treatment strategies.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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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.