방사선치료를 위한 CT 검사 시 3DCT와 4DCT에 대한 피폭선량 고찰
― Consideration on Measured Patients Dose of Three-Dimensional and Four- Dimensional Computer Tomography when CT-Simulation to Radiation Therapy ―
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초록
방사선치료를 위한 CT 검사 시 동일 환자에 대하여 3차원영상과, 호흡주기영상을 획득하기 위한 컴퓨터단층촬영에서 환자의 피폭선량을 측정하고자 SOMATON SENSATION OPEN(SIEMENS, GERMANY)을 이용하여내원환자 중 폐암환자 10명, 간암환자 10명의 CT 검사 시 피폭선량을 측정했다. 환자가 받는 피폭선량은 The volume CT dose index(CTDIvol), Dose Length Product(DLP)를 이용하여분석하였으며 각각의 장기들이 받는 피폭선량의 실측은 환자의 장기를 대상으로 할 수 없어 Rando 팬텀을이용 흉부검사 시 폐와 심장, 척수를, 복부검사 시 간과 신장의 위치를 선택하여 in-vitro와 in-vivo 계측이가능한 광유도발광선량계(Optically Stimulated Luminescent Dosimeter, Landauer, Inc., USA)를 이용하여 측정하였다. 폐암환자의 CT 검사 시 10명의 CTDIvol값은 5.7배, DLP값은 약 2.4배, 간암환자의 CTDIvol값은 3.8배,DLP값은 약 1.6배의 값을 나타내었고, OSLD를 이용한 실측정치 역시 폐암환자의 경우 6배, 간암환자의 경우 5.5배의 차이를 보이는 등 4DCT 검사에서 전체적인 피폭선량의 증가를 볼 수 있었다. 방사선치료 시 호흡에 의한 치료부위의 위치변화를 4DCT 검사를 이용하여 움직임을 보정하여 치료계획시 치료용적의 정확성을 높일 수 있으나 4DCT 검사로 인한 환자의 피폭선량 증가를 고려하여 검사시간과검사범위를 줄여 피폭선량을 감소시키기 위한 노력이 필요하다.
Abstract
This study was to measure the patient dose difference between 3D treatment planning CT and 4D respiratory gating CT. Study was performed with each 10 patients who have lung and liver cancer for measured patient exposure dose by using SOMATON SENSATION OPEN(SIMENS ,GERMANY). CTDIvol and DLP value was used to analyze patient dose, and actual dose was measured in the location of liver and kidney for abdominal examination and lung, heart and spinal cord for chest examination. Rando phantom were used for the experiment. OSLD was used for in-vitro and in-vivo dosimetry. Increasing overall actual dose in 4D respiratory gated CT-simulation using OSLD increase the dose by 5.5 times for liver cancer patients and 6 times for lung cancer patients. In CT simulation of 10 lung cancer patients, CTDIvol value was increased by 5.7 times and DLP 2.4 times. For liver cancer patients, CTDIvol was risen by 3.8 times and DLP 1.6 times. The accuracy of treatment volume could be increased in 4D CT planning for position change due to the breaths of patient in the radiation therapy. However, patients dose was increased in 4D CT than 3D CT. In conclusion, constant efforts is required to reduce patients dose by reducing scan time and scan range.
참고문헌 (19)
- 동경래, "4D-CT와 호흡동조시스템을 이용한 간암 환자의 방사선치료 표적 움직임 분석", 방사선방어학회지, 35(2), pp.63~68 (2010), 대한방사선방어학회
- Wangman R, "Resporatory gating for liver tumor use in dose escalaton", int. J Radiat Oncol Biol Phys, 55(3), pp.659~668 (2003)
- European guidelines on quality criteria for computed tomography, , ~, pp.EUR 16261 (1999)
- 이창래, "MDCT의 관전압, 관전류, 슬라이스 두께, pitch 변화에 따른 팬텀의 선량 분포 측정", 의학물리, 18(3), pp.139~143 (2007), 한국의학물리학회
- V. Tsapaki, "Dose reduction in CT while maintaining diagnostic confidence, diagnostic reference levels at routine head, chest, and abdominal CT-IAEA-coordinated research project", Radiology, 240(3), pp.828~834 (2006)
- Aznar MC, "A Monte Carlo study of the energy dependence of Al2O3: C crystals for real-time in vivo dosimetry in mammography", Radiat. Prot. Dosimetry, 114(1), pp.444~449 (2005)
- Jursinic PA, "Characterization of optically stimulated luminescent dosimeters, OSLDs, for clinical dosimetric measurements", Med. Phys, 34(12), pp.4594~4604 (2007)
- Viamonte A, "Radiotherapy dosimetry using a commercial OSL system", Med. Phys, 35(4), pp.1261~1266 (2008)
- Reft CS, "The energy dependence and dose response of a commercial optically stimulated luminescent detector for kilovoltage photon, megavoltage photon, and electron, proton, and carbon beams", Med. Phys, 36(5), pp.1690~1699 (2009)
- 임인철, "광자극발광선량계(OLSDs)를 이용한 직장암 방사선치료 환자의 피부선량 측정", 방사선방어학회지, 36(2), pp.86~92 (2011), 대한방사선방어학회
- Under RWM, "Benefit of respiration gated stereotactic radiotherapy for stage lung cancer an analysis of 4D CT Datasets", Int J Radiat Oncol Bio Phys, 62(2), pp.554~560 (2005)
- International Commission on Radiological Protection, "The 2007 Recommendations of the International Commission on Radiological Protection", 37(2) (2007), Elsevier Science
- Kim MC, "Clinical Comuted Tomography", pp.540~558 (2007), Chung gu Publishing co
- 이종석, "흉부 및 복부에서 AEC 적용에 따른 MDCT의 선량 감소 효과", 한국콘텐츠학회 논문지, 9(3), pp.225~231 (2009), 한국콘텐츠학회
- Ramsy CR, "Clinical efficacy of respiratory gated conformal therapy", Med Dosim, 55(3), pp.659~668 (2006)
- Lujan AE, "A method for incorporating organ motion due to breathing into 3D dose calculations", Med Phys, 26(5), pp.715~720 (1999)
- IAEA, "International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources" (1996), IAEA
- "The Guidelines of patients dose on CT examinations: The series of Radiation Safety and Management, 19, 2009", ~ (2009)
- A. Sam Beddar, "Correlation between internal fiducial tumor motion and external marker motion for liver tumors imaged with 4D-CT", Radiation Oncology Bio. Phy, 67(2), pp.630~638 (2007)