【摘 要】
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Adjacent treatment fields are commonly employed in external beam radiation therapy, such as the mantle and inverted-Y fields for the treatment of Hodgkin’s dis
【机 构】
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Department of Radiation 0ncology,Department of Physics,National Center for Radiaion Research and Tec
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Adjacent treatment fields are commonly employed in external beam radiation therapy, such as the mantle and inverted-Y fields for the treatment of Hodgkin’s disease. In some cases, the adjacent fields are orthogonal, such as the cra-niospinal fields used in the treatment of meduloblastoma. Another example is the irradiation of head and neck tumors when the lateral neck fields are placed adjacent to the anterior supraclavicular field. In each of these situations, there is a possibility of introducing very large dosage errors across the junction. Consequently, this region is at risk for tumor recurrence if it is underdosed or severe complications if it is overdosed. Four milimeter overlap and gap resulted in an unacceptable dose in homogeneity in the junction. As a result of this study, the magnitudes of hot and cold spots might be clinicaly acceptable for 3 mm gap between photon fields.
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