• Journal of Korean Neurosurgical Society
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• v.58 no.3
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• pp.211-216
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• 2015

Objectives : Although surgical resection is used to treat meningeal hemangiopericytoma (MHPC), there is a high risk of subsequent recurrence. This study investigated factors associated with treatment outcomes and recurrence in patients who had undergone surgical resection of intracranial MHPC. Methods : Fifteen patients underwent surgical treatments performed by one senior neurosurgeon between 1997 and 2013. Clinical data, radiologic images, surgical outcomes, recurrence, and other relevant characteristics were reviewed and analyzed. Results : Fifteen patients were included in the analysis, 12 (80%) of whom had tumors in the supratentorial region, and 3 (20%) of whom had tumors in the infratentorial region. Complete resection was achieved in all 15 patients, and 3 (20%) patients were administered radiosurgery and conventional radiotherapy after surgery as adjuvant radiotherapy. Three patients developed recurrence, 2 of whom had not received adjuvant radiotherapy. In 1 of the patients who had not received adjuvant radiotherapy, recurrence developed at the original tumor site, 81 months after surgery. The other 2 recurrences occurred at other sites, 78 and 41 months after surgery. The 5- and 10-year overall survival rates were 88.3%, while the 5- and 10-year recurrence-free survival rates were 83% and 52%, respectively. Additionally the mean Ki-67 index differed significantly between patients who did and did not develop recurrence (43% vs. 14%; p=0.001). Conclusion : Because of the high risk of MHPC recurrence, MHPC tumors should be completely resected, whenever feasible. However, even when complete resection is achieved, adjuvant radiotherapy might be necessary to prevent recurrence.

• The Journal of Korean Medicine
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• v.26 no.2 s.62
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• pp.1-12
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• 2005

Objectives: Malignant gliomas are often treated with cisplatin (cis-diamminedichloroplatinum(II), CDDP) and radiation but results remain unsatisfactory. Since malignant glioma displays moderate resistance to conventional therapy, a new treatment modality is needed to improve the outcome of patients with these tumors. The aim of this study was to investigate the effects of the combined use of Jongjihwan(JJH) and cisplatin(CDDP) on cultured malignant glioma cells, A172. Methodss & Results: The combined use of cisplatin and Jeongjihwan had synergistic effects on Al72 cells during 24 hr-incubation, This treatment resulted in a decrease of cell viability, Which was revealed as apoptosis Characterized by activation of caspase-3 protease as well as cleavage of poly ADP-ribose polymerase (PARP) with change of mitochondria membrane potential transition. The expression of members of the Bcl-2 protein family was modulated during co-treatment with Jeongjihwan and cisplatin. Activation of caspase-3 and mitochondrial alterations were central to co-treatment with Jeongjihwan and cisplatin-induced apoptosis. Conclusions: We conclude that co-treatment with Jeongjihwan and cisplatin-induced activation of the mitochondrial pathway enables cell death. Also, we suggest the combined theory of JJH and cisplatin could be a useful method for glioblastoma.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.4
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• pp.264-270
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• 2018

Gastrointestinal stromal tumor (GIST) is a mesenchymal tumor derived from Cajal cells originating from the myotonic plexus. The expression of tyrosine kinase (KIT) membrane receptors that are active on KIT is inhibited by the KIT inhibitor imatinib mesylate. GISTs are resistant to conventional chemotherapy, and radiation therapy is not significantly beneficial for GISTs. With the development of imatinib mesylate, approximately 81.6% of patients with advanced and metastatic GIST exhibit an effect above the stabilization response, thereby increasing the survival time. However, imatinib mesylate alone is unlikely to cure metastatic GISTs. Even with a partial or stable response, imatinib mesylate may be used for a longer time period. However, resection of grossly visible lesions should be considered for patients with a stable response during surgical treatment. In this study, we present a case of GIST with liver metastasis after imatinib mesylate treatment, which was followed up without recurrence after partial resection.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.295-301
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• 1993

Since Jan. 1991 a prospective randomized study for Stage III unresectable non small cell lung cancer (NSCLC) has been conducted to evaluate the response rate and tolerance of induction chemotherapy with MVP followed by hyperfractionated radiotherapy and evaluate the efficacy of maintenance chemotherapy in Asan Medical Center. All patients in this study were treated with hyperfractionated radiotherapy (120 cGy/fx BID, 6480 cGy/54 fx) following 3 cycles of induction chemotherapy, MVP (Mitomycin C 6 $mg/m^2,$ Vinblastin 6 $mg/m^2,$ Cisplatin 60 $mg/m^2$) and then the partial and complete responders from induction chemotherapy were randomized to 3 cycles of adjuvant MVP chemotherapy group and observation group. 48 patients were registered to this study until December 1992; among 48 patients 3 refused further treatment after induction chemotherapy and 6 received incomplete radiation therapy because of patient's refusal, 39 completed planned therapy. Twenty-three $(58\%)$ patients including 2 complete responders showed response from induction chemotherapy. Among the 21 patients who achieved a partial response after induction chemotherapy,1 patient rendered complete clearance of disease and 10 patients showed further regression of tumor following hyperfractionated radiotherapy. Remaining 10 patients showed stable disease or progression after radiotherapy. Of the sixteen patients judged to have stable disease or progression after induction chemotherapy, seven showed more than partial remission after radiotherapy but nine showed no response in spite of radiotherapy. Of the 39 patients who completed induction chemotherapy and radiotherapy, 25 patients $(64\%)$ including 3 complete responders showed more than partial remission. Nineteen patients were randomized after radio-therapy. Nine Patients were allocated to adjuvant chemotherapy group and 4/9 showed further regression of tumor after adjuvant chemotherapy. For the time being, there is no suggestion of a difference between the adjuvant chemotherapy group and observation group in distant metastasis rate and survival. Median survival time was 13 months. Actuarial survival rates at 6,12 and 18 months of 39 patients who completed this study were $84.6\%,\;53.7\%\;and\;40.3\%,$ respectively. The partial and complete responders from induction chemotherapy showed significantly better survival than non-responders (p=0.028). Incidence of radiation pneumonitis in this study group was less than that in historical control group inspite of induction chemotherapy. All patients tolerated hypertractionated radiotherapy without definite increase of acute complications compared with conventional radiotherapy group. The longer follow up is needed to evaluate the efficacies of induction and maintenance chemotherapy and survival advantage by hyperfractionated radiotherapy but authors are encouraged with an excellent tolerance, higher response rate and improvement of one year survival rate in patients of this study.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.89-95
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• 2004

Intensity-modulated radiation therapy (IMRT) often uses small beam segments. The heterogeneity effect is well known for relatively large field sizes used in the conventional radiation treatments. However, this effect is not known in small fields such as the beamlets used in IMRT. There are many factors that can cause errors in the small field i.e. electronic disequilibrium and multiple electron scattering. This study prepared geometrically regular heterogeneous phantoms, and compared the measurements with the calculations using the Convolution/Superposition algorithm and Monte Carlo method for small beams. This study used the BEAM00/EGS4 code to simulate the head of a Varian 2300C/D. The commissioning of a 6MV photon beam were performed from two points of view, the beam profiles and depth doses. The calculated voxel size was 1${\times}$1${\times}$2$\textrm{cm}^2$ with field sizes of 1${\times}$1$\textrm{cm}^2$, 2${\times}$2$\textrm{cm}^2$, and 5${\times}$5$\textrm{cm}^2$. The XiOTM TPS (Treatment Planning System) was used for the calculation using the Convolution/Superposition algorithm. The 6MV photon beam was irradiated to homogeneous (water equivalent) and heterogeneous phantoms (water equivalent ＋ air cavity, water equivalent ＋ bone equivalent). The beam profiles were well matched within :t1 mm and the depth doses were within ${\pm}$2%. In conclusion, the dose calculations of the Convolution/Superposition and Monte Carlo simulations showed good agreement with the film measurements in the small field.

• Progress in Medical Physics
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• v.12 no.2
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• pp.125-131
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• 2001

We was investigate the dosimetric characteristics of the virtual wedge and it compared to the conventional fixed wedge. Also we was evaluate the quality factor of the experimental multi-channel dosimetry system for virtual wedge. Recently virtual wedge technique and wedge fraction methods are available through the computer controlled asymmetric collimator or the independent jaw in medical linear accelerator for radiation therapy. The dosimetric characteristics are interpreted by radiation field analyzer RFA-7 system and PTW-UNIDOS system. Experimental multi-channel dosimetry system for virtual wedge was consists of the electrometer, the solid detector and array phantom. The solid detectors were constructed using commercially diodes for the assessment of quality assurance in radiotherapy. And it was used for the point dose measuring and field size scanning. The semiconductor detector and ion chamber were positioned at a dmax, 5 cm, 10 cm, 20 cm depth and its specific ratio was determined using a scanning data. Wedge angles in fixed and virtual type are compared with measurements in water phantom and it is shown that the wedge angle 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$were agree within 1$^{\circ}$ degree in 6, 10 MV photon beams. In PDD and beam flatness, experimental multi-channel disimetry system was capable of reproduceing the measured values usually to within $\pm$2.1% the statistical uncertainties of the data. It was used to describe dosimetric characteristics of virtual wedge in clinical photon beams. Also we was evaluate optimal use of the virtual wedge and improve the quality factor of the experimental multi-channel dosimetry system for virtual wedge.

• Progress in Medical Physics
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• v.24 no.2
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• pp.127-132
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• 2013

The position of the internal organs can change continually and periodically inside the body due to the respiration. To reduce the respiration induced uncertainty of dose localization, one can use a respiratory gated radiotherapy where a radiation beam is exposed during the specific time of period. The main disadvantage of this method is that it usually requests a long treatment time, the massive effort during the treatment and the limitation of the patient selection. In this sense, the combination of the real-time position management (RPM) system and the volumetric intensity modulated radiotherapy (RapidArc) is promising since it provides a short treatment time compared with the conventional respiratory gated treatments. In this study, we evaluated the accuracy of the respiratory gated RapidArc treatment. Total sic patient cases were used for this study and each case was planned by RapidArc technique using varian ECLIPSE v8.6 planning machine. For the Quality Assurance (QA), a MatriXX detector and I'mRT software were used. The results show that more than 97% of area gives the gamma value less than one with 3% dose and 3 mm distance to agreement condition, which indicates the measured dose is well matched with the treatment plan's dose distribution for the gated RapidArc treatment cases.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.141-145
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• 1999

Purpose : Granisetron is a potent, the most selective 5-HT3 receptor antagonist and is reported to b effective in treatment of radiation-induced emesis. The antiemetic efficacy and safety of oral granisteron was evaluated in patients with receiving highly emetogenic treatment by conventional fractionated irradiation. Materials and Methods : Patients with various cancers who were being treated with irradiation were accrued into the present study. The intensity of nausea was evaluated on first 24 hours and on day-7 by patients according to the degree of interference with normal daily life as followings; a) none; b) present but no interference with normal daily life (mild): c) interference with normal daily life (moderate): and d) bedridden because of nausea (severe). Non or mild state was considered to indicate successful treatment. The efficacy of antiemetic treatment was graded as follows; a) complete response; no vomiting, no worse than mild nausea and receive no rescue antiemetic therapy over the 24h period, b) major response; either one episode of vomiting or moderate/severe nausea or had received rescue medication over 24h period, or any combination of these, c) minor response; two to four episodes of vomiting over the 24h period, regardless of nausea and rescue medication, d) failure; more than four medication. The score of the most symptom was recorded and the total score over 24 hours was summarized. The complete or major response was considered to indicate successful treatment. Results : A total of 10 patients were enrolled into this study, and all were assessable for efficacy analysis. Total nausea control was achieved in 90$\%$ (9/10:none=60$\%$ plus mild=30$\%$) of total patients after 7 days. The control of vomiting by granisteron was noted in seven patients (70$\%$) of complete response and three (30$\%$) of major response with a hundred-percent successful treatment over 7 days. The minor response or treatment failure were not observed. No significant adverse events or toxicities from granisetron were recorded in patient receiving granisetron. Conclusion : We concluded that granisetron is a highly effective antiemetic agent in controlling radiotherapy-induced nausea or vomiting with a minimal toxicity profile.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.161-163
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• 2002

The BNCT(Boron Neutron Capture Therapy) facility has been developed in Hanaro(High-flux Advanced Neutron Application Reactor), a research reactor of Korea Atomic Energy Research Institute. A typical tangenial beam port is utilized with this BNCT facility. Thermal neutrons can be penetrated within the limits of the possible maximum instead of being filtered fast neutrons and gamma rays as much as possible using the silicon and bismuth single crystals. In addition to, the liquid nitrogen (LN$_2$) is used to cool down the silicon and bismuth single crystals for the increase of the penetrated thermal neutron flux. Neutron beams for BNCT are shielded using the water shutter. The water shutter was designed and manufactured not to interfere with any other subsystem of Hanaro when the BNCT facility is operated. Also, it is replaced with conventional beam port plug in order to cut off helium gas leakage in the beam port. A circular collimator, composed of $\^$6/Li$_2$CO$_3$ and polyethylene compounds, is installed at the irradiation position. The measured neutron flux with 24 MW reactor power using the Au-198 activation analysis method is 8.3${\times}$10$\^$8/ n/cm$^2$ s at the collimator, exit point of neutron beams. Flatness of neutron beams is proven to ${\pm}$ 6.8% at 97 mm collimator. According to the result of acceptance tests of the water shutter, the filling time of water is about 190 seconds and drainage time of it is about 270 seconds. The radiation leakages in the irradiation room are analyzed to near the background level for neutron and 12 mSv/hr in the maximum for gamma by using BF$_3$ proportional counter and GM counter respectively. Therefore, it is verified that the neutron beams from BNCT facility in Hanaro will be enough to utilize for the purpose of clinical and pre-clinical experiment.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.447-454
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• 2019

In order to improve and supplement the shielding method for electron beam treatment, we designed a patient-specific shielding method using a 3D printer, and evaluated the usefulness by comparing and analyzing the distribution of electron beam doses to adjacent organs. In order to treat 5 cm sized superficial tumors around the lens, a CT Simulator was used to scan the Alderson Rando phantom and the DICOM file was converted into an STL file. The converted STL file was used to design a patient-specific shield and mold that matched the body surface contour of the treatment site. The thickness of the shield was 1 cm and 1.5 cm, and the mold was printed using a 3D printer, and the patient customized shielding block (PCSB) was fabricated with a cerrobend alloy with a thickness of 1 cm and 1.5 cm. The dosimetry was performed by attaching an EBT3 film on the surface of the Alderson Rando phantom eyelid and measuring the dose of 6, 9, and 12 MeV electron beams on the film using four shielding methods. Shielding rates were 83.89%, 87.14%, 87.39% at 6, 9, and 12 MeV without shielding, 1 cm (92.04%, 87.48%, 86.49%), 1.5 cm (91.13%, 91.88% with PSCB), 92.66%) The shielding rate was measured as 1 cm (90.7%, 92.23%, 88.08%) and 1.5 cm (88.31%, 90.66%, 91.81%) when the shielding block and the patient-specific shield were used together. PCSB fabrication improves shielding efficiency over conventional shielding methods. Therefore, PSCB may be useful for clinical application.