Abstract

Purpose：This study compared 3 dimensional conformal radiation therapy (3DCRT) to intensity modulated radiation therapy (IMRT) in parotid glands sparing in head and neck cancers. Materials and Methods：Planning target volume (PTV) was outlined on each CT slice. The dose of 50.4 Gy was prescribed to the PTV with the conventional fraction, 5 fractions per week. We also outlined spinal cord and both parotid glands. With Eclipse 3 dimensional planning system, 3DCRT and IMRT planning were done.
Results
：After plan optimization, PTV dose distribution was evaluated with dose volume histogram. The 90% isodose curve covered almost all of PTV for both techniques. Maximum and median dose for spinal cord were 36.8 Gy and 34.2 Gy in 3DCRT, 39.9 GY and 37.5 Gy in IMRT. For parotid glands, mean and median dose were 33.6 Gy and 37.6 Gy in 3DCRT, 24.9 Gy and 24.5 Gy in IMRT.
Conclusion
：For the non-pharyngeal head and neck cancers, 3DCRT was cost effective radiation modality in prevention radiation therapy induced xerostomia.

• Keywords: 3 Dimensional conformal radiation therapy (3DCRT), Intensity modulated radiation therapy (IMRT), Head and neck cancer;