Dynamic wedge field techniques through computer‐controlled collimator motion and dose delivery

TLDR

Clinical treatment planning often requires varying wedge angles within a single therapeutic x‑ray field. The study introduces a dual‑pass technique to better match the prescribed isodose distribution. The technique uses computer‑controlled asymmetric collimator motion to generate and deliver dynamic wedge‑shaped dose distributions, verified by film densitometry and ionization chamber measurements. Results indicate the dual‑pass dynamic wedge technique could be a valuable clinical radiotherapy tool.

Abstract

Clinical treatment planning situations arise which require different wedge angles within segments of a single therapeutic x‐ray field. Idealized wedge‐shaped dose distributions, including combination of several wedge segments of different angle within a single field, are generated and delivered through computer control of asymmetric collimator motion and dose per field segment. A dual‐pass technique is introduced to provide improved adherence to the prescribed isodose distribution. Dynamic wedge distributions are verified by film densitometry and ionization chamber measurement. These results suggest the potential importance of this technique as an added clinical radiotherapy tool.