TURKISH JOURNAL OF ONCOLOGY
2009 , Vol 24 , Num 4
Evaluation of the conformal radiotherapy techniques in prostate cancer
İstanbul Üniversitesi Onkoloji Enstitüsü, İstanbul
OBJECTIVESWe aimed to determine the optimal radiotherapy technique enabling the most homogenous dose distribution for Clinic Target Volume (CTV) and Planned Target Volume (PTV) and providing conformal avoidance of Organs at Risk (OAR).
METHODS
CTV, PTV, and OAR were outlined by utilization of Sim-Pro
(CMS-USA) using 5 mm slice spaced computed tomography
scans. For each patient, individual 4, 5, 6, and 7 field plans,
with 18 MV photons, were assessed with XiO (CMS-USA)
3D planning workstation.
RESULTS
In comparing the different techniques, the greatest rectal
sparing was achieved with the 5 field plan (Rectal:
5F V25%=59.90±6.8 Gy, 4F V25%=62.30±10.3 Gy, 6F
V25%=69.36±5.7 Gy, 7F V25%=61.32±7.3 Gy).
CONCLUSION
While all the techniques achieved the goal of optimal homogeneity
of CTV-PTV, 4F provided the lowest femoral doses.
The greatest rectal sparing was achieved with 5 field conformal
technique.