• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.39-39
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• 2003

목 적 : 병소가 바깥쪽 측면(far-lateral targets)에 위치한 경우 감마나이프 방사선 시술이 어렵다. 저자들은 새로운 식을 도입하여 치료 좌표계를 변환시키고 환자를 측면으로 눕혀 시술이 가능함을 보고하고자 한다. 대상 : 통상적으로 병소 위치가 X축 좌표 51.5mm-148.5mm 범위 내에 있는 경우, 감마나이프는 반듯이 누운 자세에서 시술을 한다. 그러나 병소가 바깥쪽 측면에 위치한 경우(51.5mm-148.5mm 범위를 벗어난 경우) 환자는 측면으로 굽혀진 상태에서만 시술이 가능하며 이때 환자 머리에 고정한 정위기구의 전면부분은 일직선 타입이어야 한다. 환자의 치료 자세가 90도 만큼 회전된 상태이므로 X축과 Y축이 서로 치환된다. 새로운 좌표계는 감마플랜에서 계산된 방사선 조사량의 각각 좌표계들이 새로운 식에 대입하여 얻어진다. 새로운 X축 좌표는 43mm 만큼 증가하였으며 범위는 30mm-170mm 이였다. 결과 : 환자를 측면으로 눕혀서 바깥쪽 측면 병소를 시술하는 방법은 방사선 조사 중심 위치의 정확도에 영향을 미치지 않았다. 새로운 X축과 Y축 좌표계는 새로운 식으로 쉽게 치환 변환된다. 결론 : 측면으로 누워서 시술하는 방법은 X축 좌표 범위를 증가시킬 수 있었으며 감마나이프 장비에서 X축의 이축 편위 (trunnion excursion) 한계 때문에 시술을 할 수 없는 경우의 수를 줄일 수 있었다. 이 방법은 바깥쪽 측면에 위치한 병소 시술에 매우 요긴하게 사용되며 특히 여러 개의 병변을 갖고 있는 전이성 뇌종양 질환에 유용하게 사용될 수 있는 방법으로 기대된다.

• Radiation Oncology Journal
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• v.24 no.2
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• pp.88-95
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• 2006

Purpose: We evaluated whether Cyberknife radiosurgery is an effective and safe method of therapy for medically intractable trigeminal neuralgia (TN). Materials and Methods: We retrospectively analyzed the outcome of 26 patients, who failed to surgery or were not suitable candidates for invasive intervention and were treated by Cyberknife radiosurgery between March 2004 and May 2005. Radiosurgery doses of $60{\sim}64 Gy$ were delivered to the 80% isodose line prescribed to an 6 mm length of the nerve, sparing the most proximal 3 mm away from the trigeminal nerve root entry zone (median dose: 64 Gy). Results: Follow-up period was $3{\sim}15$ months (median follow-up period: 9 months) Preliminary results from a cohort of 26 patients undergoing Cyberknife radiosurgery for TN showed that pain relief was achieved in 50% (13/26) of patients within the first 24 hrs after treatment. At last follow-up, 96.2% (25/26) of patients reported early pain relief within 7 days. Treatment failure developed in 2 of 26. Poor response occurred in one patient and relapse was observed in the other patient. 3 patients had hypoesthesia (11.5%), which was the only complication observed with any of our patients. Conclusion: With these results, authors assumed that Cyberknife radiosurgery for TN could be one of safe and effective therapeutic methods.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.901-907
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• 2019

The aim of this study is to evaluate the ability of target localizations of Leksell GammaPlan(LGP) in Gamma Knife Subthalamotomy(or Pallidotomy, Thalamotomy) of functional diseases. To evaluate the accuracy of LGP's location settings, the difference Δr of the target coordinates calculated by LGP (or LSP) and author's algorithm was reviewed for 10 patients who underwent Deep Brain Stimulation(DBS) surgery. Δr ranged from 0.0244663 mm to 0.107961 mm. The average of Δr was 0.054398 mm. Transformation matrix between stereotactic space and brain atlas space was calculated using PseudoInverse or Singular Value Decomposition of Mathematica to determine the positional relationship between two coordinate systems. Despite the precise frame positioning, the misalignment of yaw from -3.44739 degree to 1.82243 degree, pitch from -4.57212 degree to 0.692063 degree, and rolls from -6.38239 degree to 7.21426 degree appeared. In conclusion, a simple in-house algorithm was used to test the accuracy for location settings of LGP(or LSP) in Gamma Knife platform and the possibility for Gamma Knife Subthalamotomy. The functional diseases can be treated with Gamma Knife Radiosurgery with safety and efficacy. In the future, the proposed algorithm for target localizations' QA will be a great contributor to movement disorders' treatment of several Gamma Knife Centers.

• Journal of the Korean Society of Radiology
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• v.10 no.7
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• pp.521-529
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• 2016

Since Gamma Knife(R) radiosurgery(GKRS) is based on a single-fraction high dose treatment strategy, independent verification for the results of Leksell GammaPlan(R) (LGP) is an important procedure in assuring patient safety and minimizing the risk of treatment errors. Several verification methods have been developed and reported previously. Thus these methods were tested statistically and tried on Leksell Gamma Knife(LGK) target treatments through the embodiment of the previously proposed algorithms(PPA). The purpose of this study was to apply and evaluate the accuracy of verification methods for LGK target treatments using PPA. In the study 10 patients with intracranial lesion treated by GKRS were included. We compared the data from PPA and LGP in terms of maximum dose, arbitrary point dose, and treatment time at the isocenter locations. All data were analyzed by Paired t-test, which is statistical method used to compare two different measurement techniques. No statistical significance in maximal dose at 10 cases was observed between PPA and LGP. Differences in average maximal dose ranged from -0.53 Gy to 3.71 Gy. The arbitrary point dose calculated by PPA and LGP was not statistically significant too. But we found out the statistical difference with p=0.021 between TMR and LGP for treatment time at the isocenter locations. PPA can be incorporated as part of a routine quality assurance(QA) procedure to minimize the chance of a wrong overdose. Statistical analyses demonstrated that PPA was in excellent agreement with LGP when considering the maximal dose and the arbitrary point dose for the best plan of GKRS. Due to the easy applicability we hope PPA can be widely used.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.843-849
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• 2022

In this study, the probability of secondary carcinogenesis was analyzed by measuring the exposure dose of surrounding normal organs during radiosurgery using a gamma knife. A pediatric phantom (Model 706-G, CIRS, USA) composed of human tissue-equivalent material was set to four tumor volumes of 0.25 cm³, 0.51 cm³, 1.01 cm³, and 2.03 cm³, and the average dose was 18.4 ± 3.4 Gy. After installing the Rando phantom on the table of the gamma knife surgical equipment, the OSLD nanoDot dosimeters were placed in the right eye, left eye, thyroid, thymus gland, right lung, and left lung to measure each exposure dose. The probability of cancer occurrence due to radiation exposure of surrounding normal organs during gamma knife radiosurgery for acoustic schwannoma disease was 4.08 cancers per 100,000 at a tumor volume of 2.03 cm³. This study is expected to be used as useful data in relation to stochastic effects in the future by studying the risk of secondary radiation exposure that can occur during stereotactic radiosurgery.

• Proceedings of the Korean Statistical Society Conference
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• 2002.05a
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• pp.7-12
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• 2002

경제활동인구조사에서 시군구의 실업자를 추정하는데 소지역 추정법을 이용하는 방안에 대한 연구는 관심의 대상이 되고 있다. 본 연구에서는 합성 추정법과 복합 추정법을 이용한 시군구 실업통계 작성법을 소개하였고 추정량이 편향이므로 잭나이프 방법을 이용한 추정량의 정도를 계산하는 절차를 설명하였으며, 광주광역시의 구별 실업통계작성을 사례로 제시하였다.

• 대한방사선치료학회:학술대회논문집
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• 2005.06a
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• pp.33-34
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• 2005

• Radioisotope journal
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• v.17 no.2
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• pp.67-69
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• 2002

• 동위원소뉴스
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• no.10 s.118
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• pp.10-11
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• 2006

• The monthly packaging world
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• s.88
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• pp.166-167
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• 2000