Parotid Gland Tumors: A Comparison of Postoperative Radiotherapy Techniques Using Three Dimensional (3D) Dose Distributions and Dose-Volume Histograms (DVHs)

摘要: Abstract Purpose: To compare different treatment techniques for unilateral of parotid gland tumors. Methods and Materials: The CT-scans a representative patient were used. field size was 9 × 11 cm, the separation 15.5 prescription depth 4.5 cm. Using 3D dose distributions, tissue inhomogeneity corrections, scatter integration (for photons) pencil beam electrons) algorithms dose-volume histogram (DVH), nine compared. [1] 6 MV photons [2] 12 MeV electrons [3] 16 [4] an ipsilateral wedge pair technique using [5] 3-field AP (wedged), PA (wedged) lateral portal [6] mixed (1:4 weighting) [7] [8] 18 20 (2:3 [9] (1:1 weighting). Results: histograms to evaluate contralateral gland, percentage volume receiving ≥ 30% prescribed 100% [1], [9], Conclusion: single photon electron-photon beams are not recommended irradiation because high doses delivered exit which associated with Xerostomia. en face electron unacceptable due excessive heterogeneity contiguous normal structures. In spite optimal fall-off achieved [3], most patients cannot tolerate resulting skin doses. We conclude that [4], [5], in providing relatively homogeneous distributions within target area minimizing relevant