• Korean Journal of Head & Neck Oncology
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• v.21 no.2
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• pp.151-157
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• 2005

목적: 다양한 발생부위에서 발생한 두경부종양을 대상으로 3차원 입체조형치료를 시도하여 표적체적 내 선량균일성과 주변장기의 선량분포변하를 알아보고자 하였다. 대상 및 방법: 1995년 1월부터 1996년 12월까지 3차원 입체조형치료를 시행 받은 38명에 분석을 시행하였다. 3차원 입체조형 치료는 동일평면 또는 비동일평면상에서 4개에서 14개의 조사면 수로 시행되었다. 3차원 입체조형치료계획시 표적 체적에 $50{\sim}82Gy$의 선량을 처방하였고, 이하선 안구, 척수, 측두하악관절 등을 보호하고자 하였다. 3차원 입체조형치료 계획을 기존의 2차원 치료계획과 비교하기 위하여 표적체적과 주변정상자기의 선량체적히스토그램, 평균선량, 표적체적 내에서 처방선량의 $95{\sim}105%$의 선량이 분포하는 체적을 비교하였다 치료계획에서 실제 치료시까지 소용되는 비용효과를 비교하였다. 대상환자의 평균추적기간은 34개월이었다. 결 과: 3차원 입체조형시료는 2차원 치료에 비해서 표적체적내 평균선량이 평균 10% 증가하였고, 주변정장기에 조사되는 방사선량이 현저히 감소됨을 관찰할 수 있었고 표적체적에 대한 등선량 곡선 분포가 우수함을 관찰할 수 있었다. 결 론: 3차원 입체조형치료는 두경부종양에서 표적체적의 선량 균일성이 증가하였고, 주변장기의 보존이 가능할 것으로 생각되었다. 따라서 본 저자들은 3차원 입체조형치료가 두경부종양에서 국소제어율과 무질병생존율 향상에 기여할 것으로 생각하였다.

• Journal of radiological science and technology
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• v.36 no.3
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• pp.237-244
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• 2013

The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OED(Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ~ 2.02 Gy, 0.36 ~ 5.01 Gy, 0.25 ~ 2.49 Gy, 0.14 ~ 6.92 Gy, 0.03 ~ 2.02 Gy, 0.01 ~ 1.06 Gy, 0.25 ~ 6.08 Gy, 0.08 ~ 0.59 Gy, 0.01 ~ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.171-177
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• 2010

연구목적 : 비인두암 환자들을 대상으로 방사선치료 시 삼차원입체조형치료기법과 용적세기조절회전치료기법을 비교하고 이하선을 포함한 정상조직 보호에 있어 그 차이점을 알아 보고자 본 연구를 시행하였다. 대상 및 방법 : 비인두암 환자 5명을 대상으로 치료계획용 CT(computed tomography)를 시행 후 삼차원입체조형방사선치료계획 과 용적세기조절회전치료계획을 시행하였다. 이를 바탕으로 얻은 선량분포, conformity index(CI) 그리고 선량체적 히스토그램을 통해 손상위험장기(organ at risk)와 계획용표적체적(planning target volume)을 비교 분석하였다. 결 과 : 분석결과 이하선에 조사되는 평균선량이 용적세기조절회전치료계획에서는 43.9%로 삼차원입체조형치료계획에서의 89.4% 보다 유의하게(p=0.043) 감소하였다. 계획용표적체적 conformity index의 경우 용적세기조절회전치료계획 (CI=1.06)에서 삼차원입체조형치료계획(CI=2.55) 보다 유의하게(p=0.043) 향상된 결과를 보였다. 결 론 : 비인두암 환자에서 용적세기조절회전 치료계획 시 삼차원입체조형치료계획 보다 유의하게 이하선에 평균선량이 줄었고 계획용 표적체적에 대한 conformity도 유의하게 향상되는 결과를 보였다. 본 연구가 적은 수의 환자를 대상으로 하였으나 용적세기조절회전치료기법을 시행 시 구강건조증의 발생을 줄일 수 있을 것으로 기대된다. 향후 더 많은 환자군을 대상으로 한 임상연구가 필요할 것으로 사료된다.

• Progress in Medical Physics
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• v.21 no.3
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• pp.298-303
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• 2010

The aim of this study was to compare the dose distribution of intensity modulated radiation therapy (IMRT) with 3 dimensional conformal radiation therapy (3DCRT) in prostate cancer. The IMRT plan and the 3DCRT plan used the 9 fields technique, respectively. In IMRT, tumor dose was a total dose of 66 Gy at 2.0 Gy per day, 5 days a week for 5 weeks. All cases were following the dose volume histogram (DVH) constraints. The maximum and minimum tumor dose constraints were 6,700 cGy and 6,500 cGy, respectively. The rectum dose constraints were <35% over 50 Gy. The bladder dose constraints were <35% over 40 Gy. The femur head dose constraints were <15% over 20 Gy. Tumor dose in the 3DCRT were 66 Gy. In IMRT, the maximum dose of PTV was 104.4% and minimum dose was 89.5% for given dose. In 3DCRT, the maximum dose of PTV was 105.3% and minimum dose was 85.5% for given dose. The rectum dose was 34.0% over 50 Gy in IMRT compared with 63.3% in 3DCRT. The bladder dose was 30.1% over 40 Gy in IMRT compared with 30.6% in 3DCRT. The right femur head dose was 9.5% over 20 Gy in IMRT compared with 17.5% in 3DCRT. The left femur head dose was 10.6% over 20 Gy in IMRT compared with 18.3% in 3 DCRT. The dose of critical organs (rectum, bladder, and femur head) in IMRT showed to reduce than dose of 3DCRT. The rectum dose over 50 Gy in IMRT was reduced 29.3% than 3DCRT. The bladder dose over 40 Gy in IMRT was similar to 3DCRT. The femur head dose over 20 Gy in IMRT was reduced about 7~8% than 3DCRT.

• Progress in Medical Physics
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• v.14 no.1
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• pp.28-33
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• 2003

The aim of the study was to assess the isocenter deviation between multiple arcs and conformal beams in frameless FSRT. Forty seven patients received single isocenter radiosurgery or therapy (SRS/T) using available framelss FSRT system from Aug. 1997 to Dec. 2m. In choosing multiple arc FSRT or conformal FSRT, we had considered one of two techniques with respect to tumor size and tumor shape. In multiple arc FSRT, the average and standard deviation (SD) of the isocenter deviation was 0.2 mm (SD 0.2 mm), 0.2 mm (SD 0.2) and 0.3 mm (SD 0.2 mm)in the lateral (x), anterior-posterior (y) and cranio-caudal directions (z). In conformal FSRT, the average deviation and SD of the isocenter deviation was 0.2 mm (SD 0.2 mm), 0.3 mm(0.2 mm) and 0.4 mm (SD 0.2 mm) in the x, y and z directions. The average spacial deviation ($\Delta$r) was 0.41 mm and 0.54 mm in multiple arcs and conformal beams, respectively. The isocenter deviation using frameless FSRT system was similar value between multiple arcs and conformal beams. In practice, we believed we can select the appropriate treatment technique according to tumor shape and size.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.123-129
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• 2002

Purpose : The purpose of this study 띤as to determine the potential role of three-dimensional conformal radiotherapy (3D-CRT) in the treatment of primary unresectable hepatocellular carcinoma. The preliminary results on the efficacy and the toxicity of 3D-CRT are reported. Materials and Methods : Seventeen patients were enrolled in this study, which was conducted prospectively from January 1995 to June 1997. The exclusion criteria included the presence of extrahepatic metastasis, liver cirrhosis of Child-Pugh classification C, tumors occupying more than two thirds of the entire liver, and a performance status of more than 3 on the ECOG scale. Two patients were treated with radiotherapy only while the remaining 15 were treated with combined transcatheter arterial chemoembolization. Radiotherapy was given to the field including the tumor plus a 1.5 cm margin using a 3D-CRT technique. The radiation dose ranged from $36\~60\;Gy$ (median; 59.4 Gy). Tumor response was based on a radiological examination such as the CT scan, MR imaging, and hepatic artery angiography at $4\~8$ weeks following the completion of treatment. The acute and subacute toxicities were monitored. Results : An objective response was observed in 11 out of 17 patients, giving a response rate of $64.7\%$. The actuarial survival rate at 2 years was $21.2\%$ from the start of radiotherapy (median survival; 19 months). Six patients developed a distant metastasis consisting of a lung metastasis in 5 patients and bone metastasis in one. The complications related to 30-CRT were gastro-duodenitis $(\geq\;grade\;2)$ in 2 patients. There were no treatment related deaths and radiation induced hepatitis. Conclusion : The preliminary results show that 3D-CRT is a reliable and effective treatment modality for primary unresectable hepatocellular carcinoma compared to other conventional modalities. Further studies to evaluate the definitive role of the 3D-CRT technique in the treatment of primary unresectable hepatocellular carcinoma are needed.

• Journal of the Korean Society of Radiology
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• v.7 no.6
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• pp.409-414
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• 2013

In this study, we evaluated to the superiority of treatment techniques on prostate cancer, apply to each other treatment techniques-3D conformal therapy versus IMRT-using dose distribution and dose coverages. Obtained 10 patients CT simulation, divided tumor volume and critical organs. Prescription dose was 80 Gy on tumor volume and Each of plans was set by two different plans. As a result, Dose coverage was superior to IMRT. The IMRT's tumor absorbed dose(100.2%) was close to prescription doses. Normal tissue(bladder, rectal, bowel Lt Rt fumoral head) absorbed dose rate was superior. In other words, the radiation therapy of prostate cancer with intensity modulated radiation therapy was better than conformal radiation therapy on dose.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.265-274
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• 1998

Purpose : This prospective study has been conducted to assess the value of three dimensional conformal radiation therapy (3DCRT) for lung cancer and to determine its potential advantage over current treatment approaches. Specific aims of this study were to 1) find the most ideal 3DCRT technique 2) establish the maximum tolerance dose that can be delivered with 3DCRT and 3) identify patients at risk for development of radiation pneumonitis. Materials and Methods : Beginning in Nov. 1994, 95 patients with inoperable non-small cell lung cancer (stage I; 4, stage II; 1, stage IIIa; 14, stage IIIb; 76) were entered onto this 3D conformal trial Areas of known disease and elective nodal areas were initially treated to 45 Gy and then using 3DCRT technique 65 to 70 Gy of total dose were delivered to the gross disease. Sixty nine patients received 65 Gy of total dose and 26 received 70 Gy Seventy eight patients (82.1$\%$) also received concurrent MVP chemotherapy. 3DCRT plans were compared with 2D plans to assess the adequacy of dose delivery to target volume, dose volume histograms for normal tissue, and normal tissue complication Probabilities (NTCP). Results : Most of plans (78/95) were composed of non-coplanar multiple (4-8) fields. Coplanar segmented conformal therapy was used in 17 pateints, choosing the proper gantry angle which minimize normal lung exposure in each segment. 3DCRT gave the full dose to nearly 100$\%$ of the gross disease target volume in all patients. The mean NTCP for ipsilateral lung with 3DCRT (range; 0.17-0.43) was 68$\%$ of the mean NTCP with 2D treatment planning (range; 0.27-0.66). DVH analysis for heart showed that irradiated volume of heart could be significantly reduced by non-coplanar 3D approach especially in the case of left lower lobe lesion. Of 95 patients evaluable for response, 75 (79$\%$), showed major response including 25 (26$\%$) with complete responses and 50 (53$\%$) with partial responses. One and two rear overall survivals of stage III patients were 62.6$\%$ and 35.2$\%$ respectively. Twenty percent (19/95) of patients had pneumonitis; Eight patients had grade 1 pneumonitis and 11 other patients had grade 2. Comparison of the average of NTCP for lung showed a significant difference between patients with and without radiation pneumonitis. Average NTCP for Patients without complication was 62$\%$ of those with complications. Conclusions : This study showed that non-coplanar multiple fields (4-8) may be one of the ideal plans for 3DCRT for lung cancer. It also suggested that 3DCRT may provide superior delivery of high dose radiation with reduced risk to normal tissue and that NTCP can be used as a guideline for the dose escalation.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.455-467
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• 1998

Purpose : To evaluate influences associated with radiation treatment planning obtained with the patient breathing freely. Materials and Methods : We compared reduction or elimination of planning target volume (PTV) margins with 2-D conventional plan with inclusion of PTV margins associated with breathing with 3-D conformal therapy. The respiratory non gated 3-D conformal treatment plans were compared with respiratory gated conventional 2-D plans in 4 patients with hepatocellular carcinomas. Isodose distribution, dose statistics, and dose volume histogram (DVH) of PTVs were used to evaluate differences between respiratory gated conventional 2-D plans and respiratory non gated 3-D conformal treatment plans. In addition. the risk of radiation exposure of surrounding normal liver and organs are evaluated by means of DVH and normal tissue complication probabilities (NTCPs). Results : The vertical movement of liver ranged 2-3 cm in all patients. We found no difference between respiratory gated 2-D plans and 3-D conformal treatment plans with the patients breathing freely. Treatment planning using DVH analysis of PTV and the normal liver was used for all patients. DVH and calculated NTCP showed no difference in respiratory gated 2-D plans and respiratory non gated 3-D conformal treatment plans. Conclusion : Respiratory gated radiation therapy was very important in hepatic tumors because radiation induced hepatitis was dependent on remaining normal liver volume. Further investigational studies for respiratory gated radiation.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.583-592
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• 2018

In this study, plans to apply 3D conformal radiotherapy, intensity modulated radiotherapy, and volumetric intensity modulated arc radiotherapy to esophageal cancer radiotherapy were compared. In particular, arc therapy was applied to reduce irradiated volume and spread of low-dose during intensity modulated radiation therapy and volumetric intensity modulated arc radiotherapy by limiting part of irradiated angle, in order to compare target doses and dose for surrounding normal tissues of the two methods and those of 3D conformal radiotherapy. No significant difference in target dose was found among the three methods. The 5 Gy volume(V5) of the lung showed 56.53% of conformal radiotherapy, 52.03% of intensity modulated radiotherapy, and 47.84% of volumetric modulated arc therapy(CRT-IMRT p=0.035, CRT-VMAT p<0.001, IMRT-VMAT p<0.001). The 10 Gy volume(V10) showed a significant difference in conformal radiotherapy 35.12%, intensity modulated radiotherapy 34.04%, and volumetric modulated arc radiotherapy 33.28%, showing significant difference in intensity modulated radiotherapy(p=0.018), volumetric modulated arc therapy(p=0.035), no significant difference in dose was found at 20 Gy volume. The mean dose and 20 Gy volume of the heart were not significantly different according to the treatment plan, but the 30 and 40 Gy volumes were 37.16% and 22.46% in the volumetric modulated arc radiotherapy, showing significant differences(p=0.028) in comparison with conformal radiotherapy. It is believed that, by limiting part of the irradiated angle during intensity modulated radiotherapy and volumetric intensity modulated arc radiotherapy, the irradiated volume and, thereby, the 5-10 Gy area and toxicity of the lung can be reduced while maintaining dose distribution of the target dose.