• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.357-362
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• 2008

A method for synthesizing o-carborane substituted tetrahydroisoquinolines containing a polar functional group such as sulfamide, sulfonic, or phosphoric acid on the nitrogen atom of the piperidine ring, starting from arylethylamine, N-(2-arylethyl)sulfamide, N-(2-arylethyl)sulfamic acid or 2-arylethylamidophosphate, is described. In vitro studies showed the desired compounds 10, 15, 19, and 25 synthesized accumulate to high levels in B-16 melanoma cells with low cytotoxicity.

• Progress in Medical Physics
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• v.27 no.1
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• pp.14-24
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• 2016

Since the head and neck region is densely located with organs at risk (OAR), OAR-sparing is an important issue in the treatment of head and neck cancers. This study-in which different treatment plans were performed varying the head tilt angle on brain tumor patients-investigates the optimal head elevation angle for sparing normal organs (e.g. the hippocampus) and further compares the dosimetric characteristics of different types of radiation equipment. we performed 3D conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and tomotherapy on 10 patients with brain tumors in the frontal lobe while varying the head tilt angle of patients to analyze the dosimetric characteristics of different therapy methods. In each treatment plan, 95% of the tumor volume was irradiated with a dose of 40 Gy in 10 fractions. The step and shoot technique with nine beams was used for IMRT, and the same prescription dose was delivered to the tumor volume for the 3D-CRT and tomotherapy plans. The homogeneity index, conformity index, and normal tissue complication probability (NTCP) were calculated. At a head elevation angle of $30^{\circ}$, conformity of the isodose curve to the target increased on average by 53%, 8%, and 5.4%. In 3D-CRT, the maximum dose received by the brain stem decreased at $15^{\circ}$, $30^{\circ}$, and $40^{\circ}$, compared to that observed at $0^{\circ}$. The NTCP value of the hippocampus observed in each modality was the highest at a head and neck angle of $0^{\circ}$ and the lowest at $30^{\circ}$. This study demonstrates that the elevation of the patients' head tilt angle in radiation therapy improves the target region's homogeneity of dose distribution by increasing the tumor control rate and conformity of the isodose curve to the target. Moreover, the study shows that the elevation of the head tilt angle lowers the NTCP by separating the tumor volume from the normal tissues, which helps spare OARs and reduce the delivered dose to the hippocampus.

• Polymer(Korea)
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• v.30 no.6
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• pp.572-575
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• 2006

In this work, a variety of polymer based jelly phantoms suitable for the hyperthermia operations to human organs was synthesized in order to confirm the possibility of auxiliary cancer therapy. Specifically, using an appropriate material composition including polyethylene, Jelly phantoms for brain was prepared and characterized their electrical properties suitable for the monitoring the effect of electromagnetic wave from code division multiple access (CDMA) and personal communication service (PCS) on the human body. In the future, after injection of ferromagnetic nanoparticle into the jelly phantoms, new approach to propose the cancer therapy can be anticipated by monitoring the degree of temperature rise in human body using the photograph of Infrared camera.

• Progress in Medical Physics
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• v.29 no.4
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• pp.157-163
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• 2018

Plans converted using dose-volume-histogram-based plan conversion (DPC) were evaluated by comparing them to the original plans. Changes in the dose volumetric (DV) parameters of five volumetric modulated arc therapy (VMAT) plans for head and neck (HN) cancer and five VMAT plans for prostate cancer were analyzed. For the HN plans, the homogeneity indices (HIs) of the three planning target volumes (PTV) increased by 0.03, 0.02, and 0.03, respectively, after DPC. The maximum doses to the PTVs increased by 1.20, 1.87, and 0.92 Gy, respectively, after DPC. The maximum doses to the optic chiasm, optic nerves, spinal cord, brain stem, lenses, and parotid glands increased after DPC by approximately 4.39, 3.62, 7.55, 7.96, 1.77, and 6.40 Gy, respectively. For the prostate plans after DPC, the HIs for the primary and boost PTVs increased by 0.05 and 0.03, respectively, and the maximum doses to each PTV increased by 1.84 and 0.19 Gy, respectively. After DPC, the mean doses to the rectum and femoral heads increased by approximately 6.19 and 2.79 Gy, respectively, and those to the bladder decreased by 0.20 Gy when summing the primary and boost plans. Because clinically unacceptable changes were sometimes observed after DPC, plans converted by DPC should be carefully reviewed before actual patient treatment.

• Journal of radiological science and technology
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• v.46 no.3
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• pp.239-246
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• 2023

In this study, we assessed the effect of reduction of tumor volume in the head and neck cancer by using RANDO phantom in Static Intensity-Modulated Radiation Therapy (S-IMRT) and Volumetric-Modulated Arc Therapy (VMAT) planning. RANDO phantom's body and protruding volumes were delineated by using Contour menu of Eclipse™ (Varian Medical System, Inc., Version 15.6, USA) treatment planning system. Inner margins of 2 mm to 10 mm from protruding volumes of the reference were applied to generate the parameters of reduced volume. In addition, target volume and Organ at Risk (OAR) volumes were delineated. S-IMRT plan and VMAT plan were designed in reference. These plans were assigned in the reduced volumes and dose was calculated in reduced volumes using preset Monitor unit (MU). Dose Volume Histogram (DVH) was generated to evaluate treatment planning. Conformity Index (CI) and R² in reference S-IMRT were 0.983 and 0.015, respectively. There was no significant relationship between CI and the reduced volume. Homogeneity Index (HI) and R² were 0.092 and 0.960, respectively. The HI increased when volume reduced. In reference VMAT, CI and R² were 0.992 and 0.259, respectively. There was no relationship between the volume reduction and CI. On the other hand, HI and R² were 0.078 and 0.895, respectively. The value of HI increased when the volume reduced. There was significant difference (p<0.05) between parameters (D_mean and D_max) of normal organs of S-IMRT and VMAT except brain stem. Volume reduction affected the CI, HI and OAR dose. In the future, additional studies are necessary to incorporate the reduction of the volume in the clinical setting.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.982-987
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• 1998

Background: Surgical resection is the standad therapy for the stage I lung cancer. We analysed the risk facturs of stage I lung cancer patent and tryed to establish more effective and aggressive treatment modality. Materials and methods: A detailed analysis was undertaken to evaluate the surgical results and to define the risk factors associated with the recurrence and the survival time in 146 consecutive patients with stage I lung cancer who were diagnosed, and resected at Yonsei Medical Center from January 1990 to December 1996. Results: There were 115 males and 31 females. Their ages ranged from 27 to 79 years(mean age:58.9$\pm$9.3 years). The histologic types were squamous carcinoma in 72 cases(49.3%) and adenocarcinoma in 45 cases(30.8%). A pulmonary resection and mediastinal lymph node dissection were done in all cases. A lobectomy was performed in 96 cases(65.7%) and a pneumonectomy in 48 cases(32.9%). There were 5 operative mortalities(3.4%) and complications occured in 24 cases(16.5%). The overall 5-year survival was 64.1%, and survival time did not depend on the type of operation or histologic type. Significant predictors of decreased survival were visceral pleural invasion(p=0.0079), T2 lesion(p=0.0462), and tumor size($\geq$5 cm) in adenocarcinoma(p=0.0472). The overall incidence of recurrence was 33.3%(47 cases; local or regional 6.4%, distant 26.9%). Almost all recurrences(44cases) occurred in T2 lesions. The distant organs that failed were the contralateral lung in 13 patients, the brain in 12, the bone in 10, and other organs in 3. Conclusions: even in stage I lung cancer, we suggest that postoperative adjuvant therapy is recommended in patients with poor prognostic factors such as visceral pleural invasion, T2 lesions, and a tumor size($\geq$5 cm) in the adenocarcinoma.

• Journal of Plant Biotechnology
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• v.33 no.3
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• pp.195-207
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• 2006

Stem cells are the primordial, initial cells which usually divide asymmetrically giving rise to on the one hand self-renewals and on the other hand progenitor cells with potential for differentiation. Zygote (fertilized egg), with totipotency, deserves the top-ranking stem cell - he totipotent stem cell (TSC). Both the ICM (inner cell mass) taken from the 6 days-old human blastocyst and ESC (embryonic stem cell) derived from the in vitro cultured ICM have slightly less potency for differentiation than the zygote, and are termed pluripotent stem cells. Stem cells in the tissues and organs of fetus, infant, and adult have highly reduced potency and committed to produce only progenitor cells for particular tissues. These tissue-specific stem cells are called multipotent stem cells. These tissue-specific/committed multipotent stem cells, when placed in altered environment other than their original niche, can yield cells characteristic of the altered environment. These findings are certainly of potential interest from the clinical, therapeutic perspective. The controversial terminology 'somatic stem cell plasticity' coined by the stem cell community seems to have been proved true. Followings are some of the recent knowledges related to the stem cell. Just as the tissues of our body have their own multipotent stem cells, cancerous tumor has undifferentiated cells known as cancer stem cell (CSC). Each time CSC cleaves, it makes two daughter cells with different fate. One is endowed with immortality, the remarkable ability to divide indefinitely, while the other progeny cell divides occasionally but lives forever. In the cancer tumor, CSC is minority being as few as 3-5% of the tumor mass but it is the culprit behind the tumor-malignancy, metastasis, and recurrence of cancer. CSC is like a master print. As long as the original exists, copies can be made and the disease can persist. If the CSC is destroyed, cancer tumor can't grow. In the decades-long cancer therapy, efforts were focused on the reducing of the bulk of cancerous growth. How cancer therapy is changing to destroy the origin of tumor, the CSC. The next generation of treatments should be to recognize and target the root cause of cancerous growth, the CSC, rather than the reducing of the bulk of tumor, Now the strategy is to find a way to identify and isolate the stem cells. The surfaces of normal as well as the cancer stem cells are studded with proteins. In leukaemia stem cell, for example, protein CD 34 is identified. In the new treatment of cancer disease it is needed to look for protein unique to the CSC. Blocking the stem cell's source of nutrients might be another effective strategy. The mystery of sternness of stem cells has begun to be deciphered. ESC can replicate indefinitely and yet retains the potential to turn into any kind of differentiated cells. Polycomb group protein such as Suz 12 repress most of the regulatory genes which, activated, are turned to be developmental genes. These protein molecules keep the ESC in an undifferentiated state. Many of the regulator genes silenced by polycomb proteins are also occupied by such ESC transcription factors as Oct 4, Sox 2, and Nanog. Both polycomb and transcription factor proteins seem to cooperate to keep the ESC in an undifferentiated state, pluripotent, and self-renewable. A normal prion protein (PrP) is found throughout the body from blood to the brain. Prion diseases such as mad cow disease (bovine spongiform encephalopathy) are caused when a normal prion protein misfolds to give rise to PrP$^{SC}$ and assault brain tissue. Why has human body kept such a deadly and enigmatic protein? Although our body has preserved the prion protein, prion diseases are of rare occurrence. Deadly prion diseases have been intensively studied, but normal prion problems are not. Very few facts on the benefit of prion proteins have been known so far. It was found that PrP was hugely expressed on the stem cell surface of bone marrow and on the cells of neural progenitor, PrP seems to have some function in cell maturation and facilitate the division of stem cells and their self-renewal. PrP also might help guide the decision of neural progenitor cell to become a neuron.

• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.13-20
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• 2022

Purpose : IMRT using Tomotherapy during nasopharyngeal cancer radiation therapy irradiate an accurate dose to tumor tissues and is effective to reduce a dose rapidly in normal tissues. However, this has high MU and long Beam On Time. This study aims to analyze differences in tumors, normal tissues and low-dose distributions and the efficiency of Split VMAT after applying Helical IMRT (Tomotherapy), VMAT (Linac : 2Arc) and Split VMAT (Linac : 4Arc) plans. Materials and Methods : This study targeted ten nasopharyngeal cancer patients of this hospital and compared three treatment plans (Helical IMRT, VMAT, Split VMAT). For Helical IMRT planning, Precision^® (Version 1.1.1.1, Accuray, USA) was used, and for VMAT and Split VMAT planning, Pinnacle^3® (Version 9.10, Philips, USA) was used. The total dose applied was 38.4 Gy / 32 Gy (Daily Dose 2.4 Gy (GTV + 0.3 cm) / 2 Gy (CTV + 0.3 cm) 16Fx), and for GTV + 0.3 cm (P_GTV), 95% of V_38.4Gy was prescribed. VMAT with an angle of 360° 2Arc was applied, and for Split VMAT, the field was divided into the right, the left, the top and the bottom and an angle of 360° 4Arc, 6MV was set. For evaluating the quality of the treatment plans, differences in tumors, normal tissues and low-dose area were compared, and Beam On Time was measured to analyze the efficiency. Results : When calculating the mean values of evaluation items of the three treatment plans (Helical IMRT, VMAT, Split VMAT) for the patients, the H.I (Homogeneity Index) of P_GTV was 1.04, 1.11 and 1.1 respectively, and the C.I (Confomity Index) of P_CTV was 1.03, 0.99 and 1.00 respectively. The mean dose of RT Parotid Gland (Gy) was 14.54, 17.06 and 14.76 respectively, the mean dose of LT Parotid Gland (Gy) was 14.32, 17.32 and 15.09 respectively, the maximum dose of P_Cord (Spinal Cord + 0.3 cm) (Gy) was 20.57, 22.59 and 21.06 respectively, and the maximum dose of Brain Stem (Gy) was 22.35, 23.99 and 21.68 respectively. The 50% isodose curve (cc) was 1332, 1132.5 and 1065.2 respectively. Beam On Time (sec) was 373.7, 130.7 and 254.4 respectively. Conclusion : Displaying a similar treatment plan quality to Helical IMRT, which is used a lot for head and neck treatment, Split VMAT reduced the low-dose area and Beam On Time and produced a better result than VMAT. Therefore, it is considered that Split VMAT is effective not only for nasopharyngeal cancer but also for other head and neck cancers.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1811-1815
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• 2014

Background: In clinical trials with no upper age limit, the proportion of older patients is usually small, probably reflecting the more conservative approach adopted by clinicians when treating the elderly. An exploratory analysis of elderly patients in the RECORD-1 Trial showed that patients ${\geq}$ 65 y.o. had superior median PFS than overall RECORD-1 population (5.4 months and 4.9 months, respectively). We investigated the efficacy, relative benefit and safety of Everolimus (EVE) as sequential therapy after failure of VEGFr-TKI therapy for older patients with metastatic renal cell cancer (mRCC), in daily practice. Materials and Methods: 172 consecutive IRB approved patients with mRCC (median age 65, M:F 135/37, 78% clear cell) who received salvage EVE at 39 tertiary institutions between October 2009 and August 2011 were included in this analysis. Some 31% had progressed on sunitinib, 22% on sorafenib, 1% on axitinib, 41% on sequential therapy, and 5% had received other therapy. Patients with brain metastases were not included and 95% of the patients had a ECOG (Eastern Cooperative Oncology Group) performance status (PS) of 0 or 1. Previous radiotherapy was an exclusion criterion, but prior chemotherapy was permitted. Adequate organ function and hematologic parameters were mandatory. EVE administration was approved by the institutional review board at each participating institution and signed informed consent was obtained from all patients. Results: Median time of the whole cohort to last follow-up was 3.5 months (range 0.4-15.2 months). Forty four percent were continuing to take EVE at last followup. There were 86 (50%) patients ${\geq}$ 65 y.o. and 86 (50%) <65 y.o. The percentage of patients who showed PR/SD was higher in the older group than in the younger one (5.9%/61.2% vs 1.2%/46.5%, respectively). Median survival of older patients was also significantly longer (3.5 +/- 0.31 vs 3.1 +/- 0.34, hazard ratio=0.45, CI; 0.255-0.802). Analysis using Cox regression model adjusted for gender, PS, number of metastases, site of metastases, histology, smoking history and age detected an association between age and PFS (p=0.011). The frequency of adverse events in elderly patients treated with EVE was no greater than that in younger patients, although such toxicity may have had a greater impact on their quality of life. Conclusions: Older patients should not generally be excluded from accepted therapies (mTOR inhibitors after failure of VEGFr-TKI therapy) for mRCC.

• Journal of Chest Surgery
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• v.56 no.1
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• pp.25-32
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• 2023

Background: We reviewed the clinical outcomes of patients with oligometastatic (OM) non-small cell lung cancer (NSCLC) who received multimodal therapy including lung surgery. Methods: We retrospectively analyzed 117 patients with OM NSCLC who underwent complete resection of the primary tumor from 2014 to 2017. Results: The median follow-up duration was 2.91 years (95% confidence interval, 1.48-5.84 years). The patients included 73 men (62.4%), and 76 patients (64.9%) were under the age of 65 years. Based on histology, 97 adenocarcinomas and 14 squamous cell carcinomas were included. Biomarker analysis revealed that 53 patients tested positive for epidermal growth factor receptor, anaplastic lymphoma kinase, or ROS1 mutations, while 36 patients tested negative. Metastases were detected in the brain in 74 patients, the adrenal glands in 12 patients, bone in 5 patients, vertebrae in 4 patients, and other locations in 12 patients. Radiation therapy for organ metastasis was performed in 81 patients and surgical resection in 27 patients. The 1-year overall survival (OS) rate in these patients was 82.8%, and the 3- and 5-year OS rates were 52.6% and 37.2%, respectively. Patients with positive biomarker test results had 1-, 3-, and 5-year OS rates of 98%, 64%, and 42.7%, respectively. These patients had better OS than those with negative biomarker test results (p=0.031). Patients aged ≤65 years and those with pT1-2 cancers also showed better survival (both p=0.008). Conclusion: Surgical resection of primary lung cancer is a viable treatment option for selected patients with OM NSCLC in the context of multimodal therapy.