전립선암의 세기조절방사선치료와 입체조형방사선치료에서 선량분포 특성 비교

Abstract

Purpose：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. Materials and Methods：The IMRT plan and the 3DCRT plan used the 9 fields technique, respectively. In IMRT, tumor dose was a total dose of 50 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 5,075 cGy and 4,925 cGy, respectively. The rectum dose constraints were <35% over 40 Gy. The bladder dose constraints were <35% over 30 Gy. The femur head dose constraints were <15% over 16 Gy. Tumor dose in the 3DCRT were 50 Gy. Results ：In IMRT, the maximum dose of PTV was 101.9% and minimum dose was 89.5% for given dose. In 3DCRT, the maximum dose of PTV was 103.5% and minimum dose was 86.5% for given dose. The rectum dose was 29.2% over 40 Gy in IMRT compared with 67.9% in 3DCRT. The bladder dose was 30.1% over 30 Gy in IMRT compared with 30.6% in 3DCRT. The right femur head dose was 5.3% over 16 Gy in IMRT compared with 8.3% in 3DCRT. The left femur head dose was 6.8% over 16 Gy in IMRT compared with 9.1% in 3 DCRT. Conclusion：The dose of critical organs (rectum, bladder, and femur head) in IMRT showed to reduce than dose of 3DCRT. The rectum dose over 40 Gy in IMRT was reduced 38.7% than 3DCRT. The bladder dose over 30 Gy in IMRT was similar to 3DCRT. The femur head dose over 16 Gy in IMRT was reduced about 2.3∼3% than 3DCRT.