1. Department of Radiotherapy, a. The First Medical Center丨 b. The Fifth Medical Center, Chinese PLA General Hospital, Beijing
100853, China丨 2. Department of Radiotherapy, The First Hospital Affiliated to Tsinghua University, Beijing 100016, China
Abstract：Objective To compare the dosimetric characteristics of intensity modulated radiotherapy (IMRT) for prostate cancer
between domestic and imported linear accelerators. Methods A total of 25 patients with prostate cancer were randomly selected. The
IMRT plans based on the domestic and imported linear accelerators were designed respectively. The dosimetric parameters of target
area and organs at risk in the two groups were analyzed by DVH. The passing rate was verified by comparing the monitor unit (MU)
and the dose, and the efficiency and accuracy of the plans were evaluated. Results The target area was well covered by prescription
dose in both groups. There was no significant difference between the two groups except that D2% and D5% imported group were better
than domestic group (P<0.05). In terms of normal organ protection, the V20 of bladder and rectum in domestic group were better than
that in the imported group, while in high dose area, the advantage of imported group increased gradually with the increase of dose.
For the femoral head, the V30 in domestic group was better than that of imported group, while the V40 and V50 in the imported group
were better than those of domestic group, but only the V50 of the right femoral head had significant difference（t=-2.27, P=0.03）.
The passing rate of the plan verification in the domestic group was significantly better than that of the imported group (t=9.89,
P=0.00), and the number of MU decreased by 19.5% compared with that in the imported group. Conclusion Both the domestic and
imported linear accelerators can get better target dose distribution in intensity modulated radiotherapy for prostate cancer. Although
the volume of domestic accelerators in high dose irradiation of organs at risk is relatively high, they both meet the clinical dose
requirements. Combined with the application of domestic equipment, it can be used in intensity modulated radiotherapy for prostate
cancer in hospitals of different levels.