• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.154-156
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• 2002

Brachytherapy has a long history in the treatment of cancer. However, the treatment planning technique for brachytherapy has lagged somewhat behind the corresponding developments for external beam therapy as far as the imaging technique is concerned. Currently, the orthogonal-film-based treatment planning is performed at most institutions even though the CT-based planning is available. The aim of this study is to evaluate the CT-based vs. the orthogonal-film-based treatment planning in cervix cancer. The doses to point A, point B, rectum and bladder points according to ICRU 38 were calculated for the two methods above. In addition, the volumetric studies such as 3D dose computation and DVH were obtained for the CT-based planning. For the bulky tumor, the isodose lines of point A prescription were not fairly covered for the CTV. The CT -based dose planning can overestimate the maximum dose delivered to bladder and rectum by 30%. The CT-based planning has several advantages over the orthogonal-film-based such as 3D dose display, DVH, and more accurate target delineation. It is suggested that the prescription point in cervix cancer be revised especially for the bulky tumor.

• 환경생물
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• 제24권4호
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• pp.387-391
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• 2006

Manchester system 타입의 장착기중 상, 하부에 차폐체가 장착되어 있는 Henschke 장착기를 이용하여 자궁암 근접치료시 자궁 및 주변장기의 선량분포를 평가하기 위하여 치료계획수립에 사용되는 실용프로그램 결과와 몬테칼로 모의계산 결과를 비교하였다. 또한 자궁 및 주변 정상조직이 받은 선량을 계산하기 위해 ORNL(Oak Ridge National Laboratory)에서 수립한 여성의 MIRD (Medical Internal Radiation Dose)형 모의피폭체를 이용 하여 주변장기가 받는 선량을 MCNP로 계산하였다. 몬테칼로 모사에는 MCNP 4B코드를 사용하였으며, 실용계산프로그램에는 GAMMADOT를 이용하였다 MCNP계산에는 $^{192}Ir$ 선원과 장착기의 기하학적 모양을 정밀하게 모사하여 계산 오차를 줄이도록 하였으며, 치료계획용 실용계산프로그램의 계산 조건과 동일하게 치료선원의 강내 체류시간과 체류위치를 적용하여 선량을 계산하였다. 주요 선량 비교 평가점은 Manchester system에서 사용되는 4곳과 ICRU 38에서 Manchester system을 보완하기 위해 제시한 방광표면 및 직장이였다. 실용계산 결과는 MCNP모의계산의 결과와 비교했을 때 대부분 위치에서 상대오차 4% 이내의 결과를 보였고, 난형체의 차폐체 장착효과로 인한 방광과 직장에서의 선량감쇠효과는 각각 19%, 20%였다.

• 대한핵의학회지
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• 제29권1호
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• pp.54-60
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• 1995

방사성 핵종의 체내 투여 또는 체내 오염에 의한 내부피폭 흡수선량 측정을 위하여 개발된 MIRD 씨스템을 이용하여 175mCi $^{131}I$ 치료를 받는 8명의 분화된 갑상선암의 주변림프절 전이 환자에서 전신, 위, 신장, 방광 및 골수 등의 흡수선랑을 측정하였다. 전리함 검출기와 자료저장 장치가 부착된 Eberline Smart 200 씨스템을 이용하여 전신 $^{131}I$의 시간 방사능 곡선을 얻었고, 선형 회귀분석을 하여 곡선하면적을 구한 값을 투여 방사능량(Ao)으로 나누어 체류시간($\tau$)으로 하였다. MIRDose2의 S값을 이용하여 전신흡수선량을 구하였으며 ICRP publication 53의 표준인 신장, 방광, 위의 체류시간을 이용하여, 이들 장기의 흡수선량을 구하였다. 전신 및 골수의 흡수선량은 22.4 및 25.4rad로 ICRP 최대허용선량보다 훨씬 낮았으며, 방광에 375.1, 위에 285.1rad로 심각한 증상을 초래할 정도의 선량은 아니었다. 분화된 갑상선암의 폐 및 뼈전이 환자에서 200mCi 이상 투여방사능량을 증가시킬 경우 이 방법으로 전신 및 골수 등의 흡수 선량을 평가하여 안전성을 확인할 수 있을 것으로 생각된다.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1414-1420
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• 2022

High dose rate (HDR) brachytherapy treatment planning usually involves optimization methods to deliver uniform dose to the target volume and minimize dose to the healthy tissues. Four optimizations were used to evaluate the high-risk clinical target volume (HRCTV) coverage and organ at risk (OAR). Dose-volume histogram (DVH) and dosimetric parameters were analyzed and evaluated. Better coverage was achieved with PGO (mean CI = 0.95), but there were no significant mean CI differences than GrO (p = 0.03322). Mean EQD₂ doses to HRCTV (D₉₀) were also superior for PGO with no significant mean EQD₂ doses than GrO (p = 0.9410). The mean EQD₂ doses to bladder, rectum, and sigmoid were significantly higher for NO plan than PO, GrO, and PGO. PO significantly reduced the mean EQD₂ doses to bladder, rectum, and sigmoid but compromising the conformity index to HRCTV. PGO was superior in conformity index (CI) and mean EQD₂ doses to HRCTV compared with the GrO plan but not statistically significant. The mean EQD₂ doses to the rectum by PGO plan slightly exceeded the limit from ABS recommendation (mean EQD₂ dose = 78.08 Gy EQD₂). However, PGO can shorten the treatment planning process without compromising the CI and keeping the OARs dose below the tolerance limit.

• 한국의학물리학회지:의학물리
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• 제32권4호
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• pp.130-136
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• 2021

Purpose: The Halcyon radiotherapy platform at Groote Schuur Hospital was delivered with a factory-configured analytical anisotropic algorithm (AAA) beam model for dose calculation. In a recent system upgrade, the Acuros XB (AXB) algorithm was installed. Both algorithms adopt fundamentally different approaches to dose calculation. This study aimed to compare the dose distributions of cervical carcinoma RapidArc plans calculated using both algorithms. Methods: A total of 15 plans previously calculated using the AAA were retrieved and recalculated using the AXB algorithm. Comparisons were performed using the planning target volume (PTV) maximum (max) and minimum (min) doses, D95%, D98%, D50%, D2%, homogeneity index (HI), and conformity index (CI). The mean and max doses and D2% were compared for the bladder, bowel, and femoral heads. Results: The AAA calculated slightly higher targets, D98%, D95%, D50%, and CI, than the AXB algorithm (44.49 Gy vs. 44.32 Gy, P=0.129; 44.87 Gy vs. 44.70 Gy, P=0.089; 46.00 Gy vs. 45.98 Gy, P=0.154; and 0.51 vs. 0.50, P=0.200, respectively). For target min dose, D2%, max dose, and HI, the AAA scored lower than the AXB algorithm (41.24 Gy vs. 41.30 Gy, P=0.902; 47.34 Gy vs. 47.75 Gy, P<0.001; 48.62 Gy vs. 50.14 Gy, P<0.001; and 0.06 vs. 0.07, P=0.002, respectively). For bladder, bowel, and left and right femurs, the AAA calculated higher mean and max doses. Conclusions: Statistically significant differences were observed for PTV D2%, max dose, HI, and bowel max dose (P>0.05).

• 대한수의학회지
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• 제37권1호
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• pp.103-110
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• 1997

The experiments were carried out to elucidate the relationships between neurogenic effects of electrical transmural nerve stimulation and effect of adenosine 5'-triphosphate(ATP) to purinoceptor on the urinary bladder smooth muscle of pig. The results were as follows : 1. The contractile responses induced by electrical transmural nerve stimulation(10V or 20V, 0.5msec, 10sec) were the frequency(2~64Hz) dependent manner. 2. The contractile response induced by carbachol was responsed with a dose-dependent manner and the maximum contractility was $10^{-4}M$. 3. The contractile responses induced by ATP were increased in a dose-dependent manner ($10^{-5}{\sim}10^{-3}M$). 4. The contractile response induced by electrical transmural nerve stimulation(10V, 2~32Hz, 0.5msec, 10sec) was partially blocked by the treatment with atropine($10^{-5}M$), and was powerfully inhibited by 3 times of addition with ATP($10^{-5}M$). 5. The contractile response induced by electrical transmural nerve stimulation(10V, 2~32Hz, 0.5msec, 10sec) was partially blocked by the treatment with atropine($10^{-5}M$), and was completely blocked by the desensitization of the $P_{2X}$-purinoceptor using ${\alpha}$, ${\beta}$-methylene ATP($5{\times}10^{-5}M$). These results suggest that purinergic nerve was innervated, and ATP and acetylcholine was released by the electrical transmural nerve stimulation in urinary bladder smooth muscle of pig.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6519-6524
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• 2014

The aim of this study was to evaluate the clinical outcomes of radical cystectomy (RC) and concurrent chemoradiotherapy (CRT) with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) in patients with locally advanced bladder cancer (BC). From December 2000 to February 2012, 72 patients with locally advanced BC (T3-4a, N0 or N+, M0) received either RC or CRT. RC with bilateral pelvic lymph node dissection including the common iliac region as the standard procedure. Patients in the CRT group received one cycle of MVAC followed by radiotherapy with a half dose of MVAC and then two more cycles of MVAC. Standard fractionation at a daily dose of 1.8-2.0 Gy was used, with a median total dose of 50 Gy (range, 45-60 Gy). The 3-year progression-free survival (PFS) rates in the RC and CRT groups were 56.2% and 25.6%, respectively (p=-0.015) and the 3-year overall survival (OS) rates were 63.5% and 48.1% (p=0.272). Multivariate Cox proportional hazards regression analysis with application of a propensity score indicated that RC was a significant predictor of PFS (p=0.033) but not of OS (p=0.291). Among patients with locally advanced BC, PFS was significantly prolonged in the RC group compared with the CRT group. However, RC was not a significant predictor of OS. Although the sample size in this study was small, the results suggest that patient background and postoperative quality of life should be considered when choosing treatment strategy for locally advanced BC.

• 대한방사선치료학회지
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• 제18권2호
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• pp.119-125
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• 2006

목 적: 본 연구에서는 근접치료 시 선량기준점에서 선량을 정확히 분석하고자 근접방사선치료용 다목적 팬텀(Multi Purpose Brachytherapy Phantom, MPBP)을 제작하여 그 유용성을 평가하고자 하였다. 대상 및 방법: 자체 제작된 근접방사선치료용 다목적 팬텀(MPBP)에서 다기능삽입구(Multi Function Applicator, MFA)를 이용하여 치료 시와 동일한 조건을 재현한 후 열형광선량계(TLD)를 이용하여 전산화 치료계획 장치에서 계산된 좌표와 동일한 기준점에서 선량을 측정하였다. 측정 대상은 근접방사선 치료환자 중 탄뎀(tandem)과 난형체(ovoid)를 사용한 자궁경부암 환자 4명을 대상으로 환자 당 5회씩 총 20회 A point와 B point 그리고 방광에서 선량을 측정하였다. 결 과: MPBP에서 TLD의 측정 결과는 A Point에서 측정한 환자의 상대오차가 각각 -3.2%, -0.2%, 0%, 3.8%를 보였고, B point에서는 -1.4%, -1.4%, 2.4%, 4.0%를 보였다. 그리고 방광에서는 1.3%, 2%, 5.4%, 7.15%의 상대오차를 나타내었다. 결 론: 자체 제작된 근접치료용 다목적 팬텀(MPBP)은 다기능삽입구(MFA)를 사용하여 치료 시와 동일한 조건에서 선량측정의 재현성을 이룰 수 있었고, A, B point지점과 방광의 선량을 정확히 분석할 수 있었다. 따라서 본 연구에서 제작된 근접방사선치료용 다목적 팬텀은 기준점 선량분석에 매우 유용한 것으로 판단된다.

• 대한방사선치료학회지
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• 제1권1호
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• pp.70-78
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• 1985

The intrauterine irradiation is essential to achieve adequate tumor dose to centeral tumor mass in radio therapy for uterine malignancy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The comparison study of currently using 2 systems was undertaken. The simulation films and medical records of 135 patients who was treated with intrauterine irradiation at one of general hospitals in Busan and Seoul between Jan. 1983 and June 1983, were critically analized and physical parameters of low dose rate system and remote controlled high dose rate system were measured. The physical parameters include distances between lateral walls of vaginal fornices, longitudinal and lateral angles of tandem to the body axis, the distance from the external os of uterine cervix to the central axis of ovoids, the radiation dose ratio to rectum and bladder to reference point A. Followings were summary of study results: 1. In distances between lateral walls of vaginal fornices the low dose rate system showed wide distribution and relatively larger distances. In low dose rate system 5.0-5.9 cm was $55.89\%$ 6.0-6.9 cm: $23.53\%$, 4.0-4.9cm: $10.29\%$, 3.0-3.9cm: $10.29\%$, and in high dose rate system 5.0-5.9cm was $80.59\%$, 4.0-4.9cm: $17.91\%$, $6.0\~6.9\;cm:\;1.5\%$. 2. In lateral angulation of tandem to body axis, the low does system revealed mid position (the position along body axis) $64.7\%$, Lt. deviation $19.13\%$ and Rt. deviation $16.17\%$. However the high dose rate system revealed mid position $49.26\%$ Lt. deviation $40.29\%$ and Rt. deviation $10.45\%$. 3. In longitudinal angulation of tandem to body axis the mid position was $11.77\%$ and anterior angulation $88.23\%$ in low dose rate system but in high dose rate system the mid position was $1.56\%$ and anterior angulation $98.44\%$. 4. Down ward displacement of ovoids below external os was only $2.94\%$ in low dose rate system and $67.69\%$ in high dose rate system. 5. The radiation dose ration to rectum to reference point A was $102.70\%$ in high dose rate system and $70.09\%$ in low dose rate system. The dose ratio to bladder to reference point A was $78.14\%$ in high dose rate system and $75.32\%$ in low dose rate system.

• 대한방사선기술학회지:방사선기술과학
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• 제36권1호
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• pp.31-38
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• 2013

전립선암은 남성에 발생하는 가장 흔한 악성 종양으로 2007년 우리나라에서 연 평균 5,292건이 발생하여 전체 암 발생의 3.3%로 7번째로 많이 발생하였다. 이러한 전립선암 환자의 방사선 치료 시 토모치료와 양성자 치료에 대한 특성을 비교하여 보았다. 2011년 6월부터 11월까지 일산 K 암전문병원에서 전립선암 환자 11명을 대상으로 전립선암 치료계획 시 전립선 및 주변 인접 장기인 직장과 방광에 대한 DVH와 선량 분포를 비교 분석하였다. PTV의 경우 전립선암 치료의 목적으로만 본다면 토모치료와 양성자치료에는 차이가 없었다. 또한 인접 장기인 방광과 직장에 대한 평균 용적선량을 조사한 결과 2port 양성자치료가 토모치료나 5port 양성 자치료보다 선량이 적게 들어감을 확인하였다. 또한 양성자치료가 토모치료에 비해 $H{\cdot}I$가 낮게 나타났으며, 양성자치료에서 5port가 2port보다 $H{\cdot}I$가 낮게 나타났으나, 방광과 직장에 대한 용적선량과 장비 운용 시간을 고려하면 2port가 5port에 비하여 좀 더 유리할 수 있다고 사료된다.