• Radiation Oncology Journal
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• v.29 no.2
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• pp.91-98
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• 2011

Purpose: To assess the usefulness of implanted fiducial markers in the setup of hypofractionated radiotherapy for prostate cancer patients by comparing a fiducial marker matched setup with a pelvic bone match. Materials and Methods: Four prostate cancer patients treated with definitive hypofractionated radiotherapy between September 2009 and August 2010 were enrolled in this study. Three gold fiducial markers were implanted into the prostate and through the rectum under ultrasound guidance around a week before radiotherapy. Glycerin enemas were given prior to each radiotherapy planning CT and every radiotherapy session. Hypofractionated radiotherapy was planned for a total dose of 59.5 Gy in daily 3.5 Gy with using the Novalis system. Orthogonal kV X-rays were taken before radiotherapy. Treatment positions were adjusted according to the results from the fusion of the fiducial markers on digitally reconstructed radiographs of a radiotherapy plan with those on orthogonal kV X-rays. When the difference in the coordinates from the fiducial marker fusion was less than 1 mm, the patient position was approved for radiotherapy. A virtual bone matching was carried out at the fiducial marker matched position, and then a setup difference between the fiducial marker matching and bone matching was evaluated. Results: Three patients received a planned 17-fractionated radiotherapy and the rest underwent 16 fractionations. The setup error of the fiducial marker matching was $0.94{\pm}0.62$ mm (range, 0.09 to 3.01 mm; median, 0.81 mm), and the means of the lateral, craniocaudal, and anteroposterior errors were $0.39{\pm}0.34$ mm, $0.46{\pm}0.34$ mm, and $0.57{\pm}0.59$ mm, respectively. The setup error of the pelvic bony matching was $3.15{\pm}2.03$ mm (range, 0.25 to 8.23 mm; median, 2.95 mm), and the error of craniocaudal direction ($2.29{\pm}1.95$ mm) was significantly larger than those of anteroposterior ($1.73{\pm}1.31$ mm) and lateral directions ($0.45{\pm}0.37$ mm), respectively (p<0.05). Incidences of over 3 mm and 5 mm in setup difference among the fractionations were 1.5% and 0% in the fiducial marker matching, respectively, and 49.3% and 17.9% in the pelvic bone matching, respectively. Conclusion: The more precise setup of hypofractionated radiotherapy for prostate cancer patients is feasible with the implanted fiducial marker matching compared with the pelvic bony matching. Therefore, a less marginal expansion of planning target volume produces less radiation exposure to adjacent normal tissues, which could ultimately make hypofractionated radiotherapy safer.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.155-165
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• 2010

Purpose: In order to evaluate the positional uncertainty of internal organs during radiation therapy for treatment of liver cancer, we measured differences in inter- and intra-fractional variation of the tumor position and tidal amplitude using 4-dimentional computed radiograph (DCT) images and gated orthogonal setup kilovolt (KV) images taken on every treatment using the on board imaging (OBI) and real time position management (RPM) system. Materials and Methods: Twenty consecutive patients who underwent 3-dimensional (3D) conformal radiation therapy for treatment of liver cancer participated in this study. All patients received a 4DCT simulation with an RT16 scanner and an RPM system. Lipiodol, which was updated near the target volume after transarterial chemoembolization or diaphragm was chosen as a surrogate for the evaluation of the position difference of internal organs. Two reference orthogonal (anterior and lateral) digital reconstructed radiograph (DRR) images were generated using CT image sets of 0% and 50% into the respiratory phases. The maximum tidal amplitude of the surrogate was measured from 3D conformal treatment planning. After setting the patient up with laser markings on the skin, orthogonal gated setup images at 50% into the respiratory phase were acquired at each treatment session with OBI and registered on reference DRR images by setting each beam center. Online inter-fractional variation was determined with the surrogate. After adjusting the patient setup error, orthogonal setup images at 0% and 50% into the respiratory phases were obtained and tidal amplitude of the surrogate was measured. Measured tidal amplitude was compared with data from 4DCT. For evaluation of intra-fractional variation, an orthogonal gated setup image at 50% into the respiratory phase was promptly acquired after treatment and compared with the same image taken just before treatment. In addition, a statistical analysis for the quantitative evaluation was performed. Results: Medians of inter-fractional variation for twenty patients were 0.00 cm (range, -0.50 to 0.90 cm), 0.00 cm (range, -2.40 to 1.60 cm), and 0.00 cm (range, -1.10 to 0.50 cm) in the X (transaxial), Y (superior-inferior), and Z (anterior-posterior) directions, respectively. Significant inter-fractional variations over 0.5 cm were observed in four patients. Min addition, the median tidal amplitude differences between 4DCTs and the gated orthogonal setup images were -0.05 cm (range, -0.83 to 0.60 cm), -0.15 cm (range, -2.58 to 1.18 cm), and -0.02 cm (range, -1.37 to 0.59 cm) in the X, Y, and Z directions, respectively. Large differences of over 1 cm were detected in 3 patients in the Y direction, while differences of more than 0.5 but less than 1 cm were observed in 5 patients in Y and Z directions. Median intra-fractional variation was 0.00 cm (range, -0.30 to 0.40 cm), -0.03 cm (range, -1.14 to 0.50 cm), 0.05 cm (range, -0.30 to 0.50 cm) in the X, Y, and Z directions, respectively. Significant intra-fractional variation of over 1 cm was observed in 2 patients in Y direction. Conclusion: Gated setup images provided a clear image quality for the detection of organ motion without a motion artifact. Significant intra- and inter-fractional variation and tidal amplitude differences between 4DCT and gated setup images were detected in some patients during the radiation treatment period, and therefore, should be considered when setting up the target margin. Monitoring of positional uncertainty and its adaptive feedback system can enhance the accuracy of treatments.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.38-48
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• 2022

Carcinoembryonic antigen (CEA) is an oncofetal antigen primarily detected in the peripheral blood of cancer patients, particularly in those with colorectal cancer. CEA is considered a valuable target for antigen-specific immunotherapy. In this study, we induced the anti-tumor immunity for CEA through the administration of a dendritic cell (DC) vaccine. However, there was a limitation in inducing tumor regression in the DC vaccinated mice. To enhance the efficacy of anti-tumor immunity in MC38/CEA2 tumor-bearing mice, we evaluated the effects of DC vaccine in combination with cyclophosphamide (CYP). Administration of CYP 100 mg/kg in mice resulted in significant inhibition of tumor growth in the 2-day tumor model, whereas a lower inhibition of tumor growth was seen in the 10-day tumor model. Therefore, the 10-day tumor model was selected for testing chemo-immunotherapy. The combined CYP and DC vaccine not only increased tumor antigen-specific immune responses but also induced synergistic anti-tumor immunity. Furthermore, the adverse effects of CYP such as weight loss and immunosuppression by regulatory T cells and myeloid-derived suppressor cells showed a significant reduction in the combined chemo-immunotherapy treatment compared with CYP alone. Our data suggest that chemoimmunotherapy with the DC vaccine may offer a new therapeutic strategy to induce a potent anti-tumor effect and reduce the adverse effects of chemotherapy.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.2
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• pp.123-129
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• 2007

Purpose: CT scan shows that significant tumor movement occurs in lesions located in the proximity of the heart, diaphragm, and lung hilus. There are differences concerning three kinds of type to get images following the Scan type called Axial, Helical, Cine (4D-CT) mode, when the scanning by CT. To know how each protocol describe accurately, this paper is going to give you reappearance using the moving phantom. Materials and Methods: To reconstruct the movement of superior-inferior and anterior-posterior, the manufactured moving phantom and the motor following breathing were used. To distinguish movement from captured images by CT scanning, a localizer adhered to the marker on the motor. The moving phantom fixed the movement of superior-inferior upon 1.3 cm /1 min. The motor following breathing fixed the movement of anterior-posterior upon 0.2 cm /1 min. After fixing each movement, CT scanning was taken by following the CT protocols. The movement of A localizer and volume-reappearance analyzed by RTP machine. Results: Total volume of a marker was 88.2 $cm^3$ considering movement of superior-inferior. Total volume was 184.3 $cm^3$. Total volume according to each CT scan protocol were 135 $cm^3$ by axial mode, 164.9 $cm^3$ by helical mode, 181.7 $cm^3$ by cine (4D-CT) mode. The most closely describable protocol about moving reappearance was cine mode, the marker attached localizer as well. Conclusion: CT scan should reappear concerning a exact organ-description and target, when the moving organ is being scanned by three kinds of CT protocols. The cine (4D-CT) mode has the advantage of the most highly reconstructible ability of the three protocols in reappearance of the marker using a moving phantom. The marker on the phantom has always regular motion but breathing patients don't move like a phantom. Breathing education and devices setting patients were needed so that images reconstruct breathing as exactly as possible. Users should also consider that an amount of radiation to patients is being bombed.

• Journal of Life Science
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• v.34 no.6
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• pp.418-425
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• 2024

Solid tumors are heterogeneous populations of multiple cell types. While the majority of the cells that comprise cancer are unable to divide, cancer stem cells have self-renewal and differentiation properties. Normal stem cell pathways that control self-renewal are overactivated in cancer stem cells, making cancer stem cells important for cancer cell expansion and progression. Dick first proposed the definition of cancer stem cells in acute myeloid leukemia, according to which cancer stem cells can be classified based on the expression of cell surface markers. Cancer stem cells maintain their potential in the tumor microenvironment. Multiple cell types in the tumor microenvironment maintain quiescent cancer stem cells and serve as regulators of cancer growth. Since current cancer treatments target proliferative cells, quiescent state cancer stem cells that are resistant to treatment increase the risk of recurrence or metastasis. Various signals of the tumor microenvironment induce changes to become a tumor-supportive environment by remodeling the vasculature and extracellular matrix. To effectively treat cancer, cancer stem cells and the tumor microenvironment must be targeted. Therefore, it is important to understand how the tumor microenvironment induces reprogramming of the immune response to promote cancer growth, immune resistance, and metastasis. In this review, we discuss the cellular and molecular mechanisms that can enhance immunosuppression in the tumor microenvironment.

• Radiation Oncology Journal
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• v.26 no.1
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• pp.45-55
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• 2008

Purpose: This study evaluates the association of estrogen receptor(ER), progesterone receptor(PR), Her-2, COX-2, and survivin with the clinicopathological features and outcomes in young Korean women with breast cancer using recently developed tissue microarray(TMA) technology. Materials and Methods: A cohort of 212 young patients with breast cancer diagnosed at the age of 45 years or younger from March 1994 to August 2005, were enrolled in this study. The age range of patients was $23{\sim}45$ years(median age, 39 years). The minimum and median follow-up periods were 24 months and 60 months, respectively. Serial sections of primary tumors were processed by the use of a TMA for immunohistochemical staining for five biomarkers. The correlation of these five biomarkers and the clinicopathological features and outcomes were analyzed by statistical methods. Results: The majority of the patients were stage T1(90 patients) or T2(101 patients), and 105 patients(49.5%) had an axillary node metastasis. The 5-year overall and relapse free survival rates for all of the patients were 90.4% and 82.3%, respectively, and 36 patients had a locoregional or distant metastasis as a first event. Positive expression of ER, PR, Her-2, COX-2, and survivin was determined in 38.2%, 45.3%, 25.9%, 41.5%, and 43.4%, of the tumor samples, respectively. Tumor stage, nodal status, age, as well as expression of ER, PR, and HER-2 status were significantly associated with the disease free survival rate. Tumor stage, nodal status, as well as expression of ER, PR, and HER-2 were significantly related with the overall survival rate. Expression of COX-2 and survivin were not single independent prognostic factors for the disease free and overall survival rate although co-expression of HER-2 and COX-2 had a tendency as a poor prognostic factor. By multivariate analysis, only T stage and lymph node status were significant prognostic factors, and ER status was a marginally significant prognostic factor(p=0.075). Conclusion: Expression of ER, PR and HER-2 were significant prognostic factors for the relapse free and overall survival rate. Expression of COX-2 and survivin were not prognostic factors for young women with breast cancer.

• The Korean Journal of Cytopathology
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• v.10 no.2
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• pp.121-126
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• 1999

The usefulness of E-cadherin immunostaining as a marker of malignancy in the body fluids was investigated in the present study. Thirty-three histologically proven cases of cell blocks from the pleural, peritoneal, and pericardial fluids were studied by immunocytochemistry for E-cadherin antibody using LSAB method. These cases were cytologically diagnosed as adenocarcinoma (25 cases) and atypical cells (8 cases). Tumor cells showed strong positive membranous staining for E-cadherin antibody in 21 out of 25 cases (84%) of adenocarcinoma. E-cadherin staining was not found in 6 of 8 cases of suspicious maligancy. The sensitivity and specificity were 84% and 75%, respectively. Reactive mesothelial cells and Inflammatory cells scattered were all negative. In conclusion, E-cadherin is an useful adjunctive marker to distinguish reactive mesothelial cells from the carcinoma cells in the body fluids.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.283-290
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• 2003

Purpose: To evaluate the long term significance of the squamous cell carcinoma (SCC) antigen (Ag) as a tumor marker in uterine cervix carcinoma. Materials and Methods: The SCC antigen levels of pre-radiotherapy and serial post-radiotherapy serum were analyzed in 48 patients who received radiotherapy with histologically proven primary SCC of the uterine cervix. Results: Pre-radiotherapy SCC Ag level was high ($\geq$2 ng/ml) at 79.2$\%$. After the treatment, the SCC Ag level was significantly decreased. The SCC Ag level measured at about 3 months after radiotherapy was high at 23.0$\%$. In further follow up measurements, a rise of the SCC Ag to a high level was well associated with clinical relapse. The specificity of the elevated SCC Ag level in association with recurrent or persistent disease was 100$\%$, and the sensitivity was 85.7$\%$. In 3 of 4 lung metastasis cases, lung lesions were detected in chest PA before elevation of the SCC Ag level. The median lead time of the high SCC Ag level to clinical recurrence was 4 months. Conclusion: SCC Ag was a good tumor marker for monitoring treatment effect in patients with increased pre-treatment levels except in case of early lung metastasis. Elevation of the SCC Ag level after radiotherapy accurately predicted the treatment failure with lead time of 4 months. But, in early lung metastasis cases, the SCC level may be normal temporarily. Thus, chest PA should be checked to evaluate the presence of lung metastasis.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.133-140
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• 2010

Purpose: We retrospectively investigated the effect of irradiation using helical tomotherapy in recurrent pelvic tumors that underwent prior irradiation. Materials and Methods: Fourteen patients with recurrent pelvic tumors consisting of rectal cancer (57.1%), cervical cancer (35.7%) and cancer with an unknown origin (7.1%) were treated with tomotherapy. At the time of irradiation, median tumor size was 3.5 cm and 7 patients complained of pain originating from a recurrent tumor. The median radiation dose delivered to the gross tumor volume, clinical target volume, and planning target volume was 50 Gy, 47.8 Gy and 45 Gy, respectively and delivered at 5 fractions per week over the course of 4 to 5 weeks. Treatment response and duration of local disease control were evaluated using the Response Evaluation Criteria in Solid Tumors (ver. 1.0) and the Kaplan-Meyer method. Treatment-related toxicities were assessed through Common Terminology Criteria for Adverse Events (ver. 3.0). Results: The median follow-up time was 17.3 months, while the response rate was 64.3%. Symptomatic improvement appeared in 6 patients (85.7%). The median duration time of local disease control was 25.8 months. The rates of local failure, distant failure, and synchronous local and distant failure were 57.1%, 21.4%, and 7.1%, respectively. Acute toxicities were limited in grade I or II toxicities, except for one patient. No treatment related death or late toxicity was observed. Conclusion: Helical tomotherapy could be suggested as a feasible palliative option in recurrent pelvic tumors with prior radiotherapy. However, to increase treatment effect and overcome the limitation of this outcome, a large clinical study should be performed.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.335-338
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• 2009

본 연구에서는 HIF-$1{\alpha}$의 과발현은 VEGF의 발현과 유의한 상관 관계가 있음을 보여 주었다. 그리고, HIF-$1{\alpha}$의 과발현과 E-cadherin의 발현 사이에도 연관성은 있었지만 통계적인 유의성은 없었다. 종양의 병기와 VEGF, HIF-$1{\alpha}$, E-cadherin, p53의 상관성을 살펴본 결과 E-cadherin에서만 유의성이 관찰되었다. 갑상샘 유두암종에서 HIF-$1{\alpha}$의 발현이 종양의 증식과 관련된 단백, 특히 맥관형성과 관련된 단백인 VEGF의 발현, p53의 축적 및 E-cadherin의 발현소실과의 관계, 그리고 병리학적 표지자와의 관련성을 조사하고, 갑상샘 유두암종 환자의 수술후 예후와의 관계를 알고자 하였다.