두경부(Head & Neck)종양에서 Forward IMRT 유용성에 관한 고찰

백금문,김대섭,박광호,김정만,Baek Geum Mun,Kim Dae Sup,Park Kwang Ho,Kim Chung Man 대한방사선치료학회 2003 大韓放射線治療技術學會誌 Vol.15 No.1

I. 목적 방사선 치료계획에 있어서 정상조직의 선량과 치료부위 선량의 분포는 매우 중요하다. 또한 치료부위의 균일한 선량분포를 얻기 위하여 여러 가지 방법을 이용하고 있다. 특히 두경부(Head & Neck) 종양의 방사선 치료 시 체표 윤곽의 변화가 심하여 이에 따른 선량 불균일 보정이 필요하다. 기존의 치료방법으로는 parotid gland 와 spinal cord 의 tolerance dose 이하를 유지하면서 planning target volume(PTV)에 충분한 치료 선량을 전달하기에는 여러 가지 어려움이 있다. 이에 본원에서는 Forward IMRT를 이용한 방사선 치료의 유용성 및 실용적인 정도관리 방법에 관한 연구를 하였다. II. 대상 및 방법 본 연구는 두경부(Head & Neck) 종양 비인두암(nasophrygeal cancer)의 방사선 치료가 요구되는 환자를 대상으로 하여 2차원적인 치료계획과 dynamic Mulit-Leaf Collimator(dMLC)를 이용하여 partial block technique(PBT)방법을 적용한 Forward IMRT를 위한 치료계획을 dose volume histogram(DVH)로 비교 분석하였다. 또한 정도관리(quality assurance, QA)를 위하여 필름과 pinpoint chamber를 이용하여 정확한 선량 평가를 실시하였다. III. 결과 2차원적인 치료계획과 Forward IMRT를 적용한 치료계획의 DVH를 비교 분석한 결과 Forward IMRT를 적용한 치료계획이 Rt, Lt parotid gland와 spinal cord에 들어가는 선량을 좀더 줄일 수 있었다. 이러한 Forward IMRT의 시도로 조사면의 방사선 세기가 정상조직의 보호를 개선시키고 치료의 최적화를 이룰 수 있었다. Inverse IMRT에 비해 기존의 3차원적 치료계획 장치를 이용할 수 있고 비교적 단순한 방사선 세기 패턴이므로 정도관리가 용이하였다. IV. 결론 Forward IMRT는 2차원적인 치료법에 비하여 PTV에는 균일한 선량분포를 이루면서 정상조직에는 tolerance dose 이하로 선량을 전달 할 수 있는 치료기법이었다. I. Purpose The dose distribution in normal tissues and target lesions is very important in the treatment planning. To make the uniform dose distribution in target lesions, many methods has been used. Especially in the head and neck, the dose inhomogeneity at the skin surface should be corrected. Conventional methods have a limitation in delivering the enough doses to the planning target volume (PTV) with minimized dose to the parotid gland and spinal cord. In this study, we investigated the feasibility and the practical QA methods of the forward IMRT. II. Material and Methods The treatment plan of the forward IMRT with the partial block technique using the dynamic multi-leaf collimator (dMLC) for the patients with the nasopharyngeal cancer was verified using the dose volume histogram (DVH). The films and pinpoint chamber were used for the accurate dose verification. III. Results As a result of verifying the DVH for the 2-D treatment plan with the forward IMRT, the dose to the both parotid gland and spinal cord were reduced. So the forward IMRT could save the normal tissues and optimize the treatment. Forward IMRT can use the 3-D treatment planning system and easily assure the quality, so it is easily accessible comparing with inverse IMRT IV. Conclusion The forward IMRT could make the uniform dose in the PTV while maintaining under the tolerance dose in the normal tissues comparing with the 2-D treatment.

전립선암 방사선치료 시 광자극발광선량계를 이용한 광중성자선량 평가

이주아(Joo Ah Lee),백금문(Geum Mun Back),김연수(Yeon Soo Kim),손순룡(Soon Yong Son),최관우(Kwan Woo Choi),유병규(Beong Gyu Yoo),정회원(Hoi Woun Jeong),정재홍(Jae Hong Jung),김기원(Ki Won Kim),민정환(Jung Whan Min) 대한방사선과학회(구 대한방사선기술학회) 2014 방사선기술과학 Vol.37 No.2

본 연구는 전립선암의 방사선치료에 적용되는 치료기법별 세기조절방사선치료의 적절한 조사문수의 선택 및 광중성자 피폭을 고려한 방사선 치료계획 수립을 위한 기초자료를 제공하고자 하였다. 연구대상은 2013년 9월부터 2014년 1월까지 5개월 동안 전립선암으로 방사선치료를 받은 환자 10명을 대상으로 하였다. 그리고 3-dimensional conformal radiotherapy (3D-CRT), volumetric-modulated arc radiotherapy (VMAT), intensity modulated radiation therapy (IMRT) 5, 7, 9 조사문으로 각각 치료계획을 수립하였다. 기술통계와 분산분석으로 광중성자선량의 평균적 차이를 비교하였으며, 상관관계분석과 회귀분석으로 상관성 및 영향을 분석하였다. 연구 결과, 치료기법별로는 3D-CRT가 가장 낮았다. 또한 IMRT가 가장 높게 측정되었으며, 통계적으로 매우 유의하였다 (p<.01). 세기조절방사선치료 조사문수별 광중성자선량은 평균 4.37 ± 1.08 mSv였으며, 조사문수 간에 통계적으로 매우 유의한 차이를 보였다(p<.01). 그리고 조사문수와 광중성자선량은 상관계수가 0.570으로 나타나 통계적으로 매우 유의한 양의 상관관계를 보였다 (p<.01). 조사문수와 광중성자 선량의 선형회귀분석 결과, 조사문수가 1단계 증가할 때마다 평균적으로 광중성자선량이 0.373배로 유의하게 증가하였다. 결론적으로 전립선암의 방사선치료에 빈번히 사용하고 있는 IMRT의 조사문수의 선택 및 광중성자 피폭선량 및 방사선 치료계획의 질적 수준 평가를 고려한 적절한 치료계획 선택에 있어 기초자료로 활용될 수 있으리라 기대된다. This study is to provide basic information regarding photoneutron doses in terms of radiation treatment techniques and the number of portals in intensity-modulated radiation therapy (IMRT) by measuring the photoneutron doses. Subjects of experiment were 10 patients who were diagnosedwithprostate cancer and have received radiation treatment for 5 months from September 2013 to January 2014 in the depart-ment of radiation oncology in S hospital located in Seoul. Thus, radiation treatment plans were created for 3-Dimensional Conformal Radiotherapy (3D-CRT), Volumetric-Modulated Arc Radiotherapy (VMAT), IMRT 5, 7, and 9 portals. The average difference of photoneutron dose was compared through descriptive statistics and variance analysis, and analyzed influence factors through correlation analysis and regression analysis. In summarized results, 3D-CRT showed the lowest average photoneutron dose, while IMRT caused the highest dose with statistically significance (p <.01). The photoneutron dose by number of portals of IMRT was 4.37 ± 1.08 mSv in average and statistically showed very significant difference among the number of portals (p <.01). Number of portals and photoneutron dose are shown that the correlation coefficient is 0.570, highly statistically significant positive correlation (p <.01). As a result of the linear regression analy-sis of number of portals and photoneutron dose, it showed that photoneutron dose significantly increased by 0.373 times in average as the number of portals increased by 1 stage. In conclusion, this study can be expected to be used as a quantitative basic data to select an appropriate IMRT plans regarding photo-neutron dose in radiation treatment for prostate cancer.

척수의 한계선량 극복을 위한 Dose Dynamic MLC 사용에 대한 선량 평가 및 유용성 고찰

박철수,백금문,홍동기,양오남,윤인하,윤화룡,김정만 대한방사선치료학회 2002 大韓放射線治療技術學會誌 Vol.14 No.1

종양의 움직임과 호흡주기에 따른 체적 변화에 대한 연구: 팬텀 Study

김민수,백금문,김대섭,강태영,홍동기,권경태,Kim, Min-Su,Back, Geum-Mun,Kim, Dae-Sup,Kang, Tae-Yeong,Hong, Dong-Ki,Kwon, Kyung-Tae 대한방사선치료학회 2010 대한방사선치료학회지 Vol.22 No.2

Purpose: To accurately define internal target volume (ITV) for treatment of moving target considering tumor size and respiratory motion, we quantitatively investigated volume of target volume delineated on CT images from helical CT and 4D CT scans. Materials and Methods: CT images for a 1D moving phantom with diameters of 1.5, 3, and 6 cm, acryl spheres were acquired using a LightSpeed $RT^{16}CT$ simulator. To analyze effect of tumor motion on target delineation, the CT image of the phantoms with various moving distances of 1~4 cm, and respiratory periods of 3~6 seconds, were acquired. For investigating the accuracy of the target trajectory, volume ratio of the target volumes delineated on CT images to expected volumes calculated with diameters of spherical phantom and moving distance were compared. Results: Ratio$_{helical}$ for the diameter of 1, 5, 3, and 6 cm targets were $32{\pm}14%$, $45{\pm}14%$, and $58{\pm}13%$, respectively, in the all cases. As to 4DCT, RatioMIP were $98{\pm}8%$, $97{\pm}5%$, and $95{\pm}1%$, respectively. Conclusion: The target volumes delineated on MIP images well represented the target trajectory, in comparison to those from helical CT. Target volume delineation on MIP images might be reasonable especially for treatment of early stage lung cancer, with meticulous attention to small size target, large respiratory motion, and fast breathing.

척수의 한계선량 극복을 위한 Dose Dynamic MIC 사용에 대한 선량평가 및 유용성 고찰

박철수,백금문,홍동기,양오남,윤인하,윤화룡,김정만 대한방사선사협회 2002 대한방사선사협회지 Vol.28 No.1

삼차신경통 환자의 감마나이프 수술 시 섹터블록 사용의 유용성 평가

정창영,백금문,우성호,김명준,황정호,이현비,김호성 (사)한국방사선산업학회 2018 방사선산업학회지 Vol.12 No.4

Sector block is not used for Gamma Knife surgery in patients with generalized trigeminal neuralgia but sector block is used to reduce the dose reaching the brain stem when the trigeminal ganglgia and the ‘Brain stem’, radiation sensitive tissue, are adjacent. In the Gamma Knife surgical plan of this study, a surgical plan was established using a Leksell Gamma Plan 11. 1.0 (Elekta Instrument AB, Sweden) with one patient (Block unused, Brain stem dose No volume over 12 Gy, Case 1) who did not need a sector block and four patients (Block unused, Brain stem dose 12 Gy or more, Case 2~5) with a sector block. Magnetic resonance images were obtained by MPRAGE T1 and CISS Respectively. When the trigeminal ganglion is in close proximity to the brain stem, the brain stem volume is decreased when the sector block is used, while the treatment time was increased. In conclusion, This Study evaluates the usefulness of the Sector block in brain stem through Gamma Knife surgery in trigeminal neuralgia, which is considered to be the most important factor for the Gamma Knife surgery.

호흡동조 방사선치료에 사용되고 있는 RPM (Real-time Position Management) Respiratory Gating System의 호흡변화에 따른 정확성에 대한 고찰

나준영,강태영,백금문,권경태,Na, Jun Young,Kang, Tae Young,Baek, Geum Mun,Kwon, Gyeong Tae 대한방사선치료학회 2013 대한방사선치료학회지 Vol.25 No.1

목 적: 본원에서 시행하고 있는 호흡동조 방사선치료(Respiratory Gated Radiation Therapy, RGRT)는 RPM (Real-time Position Management) Respiratory Gating System (version 1.7.5, Varian, USA)을 이용하여 실시하고 있다. 본 연구는 호흡변화에 따른 방사선치료의 정확성을 분석하고 평가하고자 한다. 대상 및 방법: 움직임을 임의로 조정할 수 있는 구동 팬텀(Motion Phantom)인 QUASAR Programmable Respiratory Motion Phantom (Moudus Medical Device Inc. CANADA)을 이용하였다. 폐암과 간암 환자 50명의 호흡을 분석하여 호흡의 변화를 관찰한 결과를 기준으로 주기 3초, 진폭 1.5 cm인 총 60초간의 기준호흡에서 매번 기저호흡(Baseline)을 기울기를 갖고 점진적으로 내려가는 경우와, 간헐적으로 기준 기저호흡 보다 더 내려가는 경우의 호흡 모양을 만들어 본원에서 사용되고 있는 Phase gating, 보통 30~70% gating 치료 방법과 동일하게 방사선을 조사하였다. 결 과: 점진적으로 매번 기저호흡이 0.01 cm, 0.03 cm, 0.05 cm씩 내려가는 호흡의 경우 모든 조건에서 방사선이 조사되었다. 간헐적으로 기저호흡이 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm 내려가는 경우도 모든 조건에서 방사선이 조사되어 RPM Respiratory Gating System에서 Phase gating 방식은 기저호흡 변화에 대하여 방사선이 모두 조사되었다. 결 론: 최적의 방사선치료를 위해 종양의 움직임을 고려하여 시행하는 호흡동조 방사선치료에서 RPM Respiratory Gating System의 Phase gating 방식은 본 연구에서와 같이 기저호흡의 변화가 호흡동조에 정확히 반영되지 않음을 알 수 있었다. 이에 호흡동조 방사선치료에는 무엇보다 환자의 호흡 관찰이 중요하다고 사료되며 호흡의 변화가 관찰되었다면 즉시 방사선치료를 멈추고 호흡을 관찰한 후 변화된 호흡상태에서 투시를 시행하여 치료부위를 다시 확인한 후에 치료를 재개하여야 한다고 사료된다. Purpose: Respiratory Gated Radiation Therapy (RGRT) has been carried out using RPM (Real-time Position Management) Respiratory Gating System (version 1.7.5, varian, USA) in Asan Medical Center. This study was to analyze and evaluate the accuracy of Respiratory Gated Radiation Therapy (RGRT) according to variation of respiration. Materials and Methods: Making variation of respiration using Motion Phantom:QUASAR Programmable Respiratory Motion Phantom (Moudus Medical Device Inc. CANADA) able to adjust respiration pattern randomly was varying period, amplitude and baseline by analyze 50 patient's respiration of lung and liver cancer. One of the variations of respiration is baseline shift gradually downward per 0.01 cm, 0.03 cm, 0.05 cm. The other variation of respiration is baseline shift accidently downward per 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm. Experiments were performed in the same way that is used RPM Respiratory Gating System (phase gating, usually 30~70% gating) in Asan Medical Center. Results: It was all exposed radiation under one of the conditions of baseline shift gradually downward per 0.01 cm, 0.03 cm, 0.05 cm. Under the other condition of baseline shift accidently downward per 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm equally radiation was exposed. Conclusion: The variations of baseline shifts didn't accurately reflect on phase gating in RPM Respiratory Gating System. This inexactitude makes serious uncertainty in Respiratory Gated Radiation Therapy. So, Must be stabilized breathing of patient before conducting Respiratory Gated Radiation Therapy. also must be monitored breathing of patient in the middle of treatment. If you observe considerable changes of breathing when conducting Respiratory Gated Radiation Therapy. Stopping treatment immediately and then must be need to recheck treatment site using fluoroscopy. If patient's respiration rechecked using fluoroscopy restabilize, it is possible to restart Respiratory Gated Radiation Therapy.

디지털 디텍터 방식(Flat Panel Detector) 혈관조영 장비의 선량비교 : Siemens-Axiom artis dBA vs Philips-Allura FD-20의 흡수선량을 중심으로

김태일,윤진호,백금문,김정이,오제선,이형진 대한인터벤션영상기술학회 2007 대한인터벤션영상기술학회지 Vol.10 No.1

영상 유도 방사선치료 시 Fiducial Marker의 Artifact에 관한 연구

김종민,김대섭,백금문,강태영,홍동기,윤화룡,권경태,Kim, Jong-Min,Kim, Dae-Sup,Back, Geum-Mun,Kang, Tae-Yeong,Hong, Dong-Ki,Yun, Hwa-Yong,Kwon, Kyeong-Tae 대한방사선치료학회 2010 대한방사선치료학회지 Vol.22 No.1

Purpose: The effect of artifact was analyzed, which occurs from fiducial marker during the liver Image Guided Radiation Therapy (IGRT) using the fiducial marker. Materials and Methods: The size of artifact of fixed fiducial marker and length of mobile fiducial marker locus were measured using the On-Board Imager system (OBI) and CT simulator, and 2D-2D matching and 3D-3D matching were carried out, respectively, and at this time, the coordinates transition value of couch was analyzed. Results: The measurement of fixed fiducial marker artifact size indicated CT 4.90, 8.10, 12.90, 19.70 mm and OBI 5.60, 10.60, 14.70, 29.40 mm based on the reference CT slice thickness of 1.25, 2.50, 5.00, and 10.00 mm. Meanwhile, the measurement of mobile fiducial marker locus length indicated CT 42.00, 43.10, 46.50 mm, and OBI 43.40, 46.00, 49.30 mm. The coordinates transition of 1.00, 2.00, and 8.00 mm occurred between 2D-2D matching and 3D-3D matching. Conclusion: It was confirmed that the therapy error increased during IGRT due to the influence of artifact when CT slice thickness increased. Thus, it may be desirable to acquire the image less than 2.50 mm in slice thickness when IGRT is implemented using the fiducial marker.

광유도발광선량계(Optically Stimulated Luminescent Dosimeter)의 선량 특성에 관한 고찰

김정미,전수동,백금문,조영필,윤화룡,권경태,Kim, Jeong-Mi,Jeon, Su-Dong,Back, Geum-Mun,Jo, Young-Pil,Yun, Hwa-Ryong,Kwon, Kyung-Tae 대한방사선치료학회 2010 대한방사선치료학회지 Vol.22 No.2

Purpose: The purpose of this study was to evaluate dosimetric characteristics of Optically stimulated luminescent dosimeters (OSLD) for dosimetry Materials and Methods: InLight/OSL $NanoDot^{TM}$ dosimeters was used including $Inlight^{TM}MicroStar$ Reader, Solid Water Phantom, and Linear accelerator ($TRYLOGY^{(R)}$) OSLDs were placed at a Dmax in a solid water phantom and were irradiated with 100 cGy of 6 MV X-rays. Most irradiations were carried out using an SSD set up 100 cm, $10{\times}10\;cm^2$ field and 300 MU/min. The time dependence were measured at 10 minute intervals. The dose dependence were measured from 50 cGy to 600 cGy. The energy dependence was measured for nominal photon beam energies of 6, 15 MV and electron beam energies of 4-20 MeV. The dose rate dependence were also measured for dose rates of 100-1,000 MU/min. Finally, the PDD was measured by OSLDs and Ion-chamber. Results: The reproducibility of OSLD according to the Time flow was evaluated within ${\pm}2.5%$. The result of Linearity of OSLD, the dose was increased linearly up to about the 300 cGy and increased supralinearly above the 300 cGy. Energy and dose rate dependence of the response of OSL detectors were evaluated within ${\pm}2%$ and ${\pm}3%$. $PDD_{10}$ and PDD20 which were measured by OSLD was 66.7%, 38.4% and $PDD_{10}$ and $PDD_{20}$ which were measured by Ion-chamber was 66.6%, 38.3% Conclusion: As a result of analyzing characteration of OSLD, OSLD was evaluated within ${\pm}3%$ according to the change of the time, enregy and dose rate. The $PDD_{10}$ and $PDD_{20}$ are measured by OSLD and ion-chamber were evaluated within 0.3%. The OSL response is linear with a dose in the range 50~300 cGy. It was possible to repeat measurement many times and progress of the measurement of reading is easy. So the stability of the system and linear dose response relationship make it a good for dosimetry.