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OBJECTIVE After acquiring 4 years of experience with Dynamic Wedge, a software-driven one-dimensional (1D) compensation system, we implemented a new software version called Enhanced Dynamic Wedge (EDW). The EDW allows larger (30 cm) and asymmetric field sizes and additional angles for wedged fields. We implemented this software on four similar dual-energy accelerators that also possess upper and lower physical wedge sets. Our goal was to implement EDW with one common wedge factor (WF) table and one set of treatment-planning files. METHODS We measured WFs with an ionization chamber and isodose profiles with both film and a diode array. We used a calculation scheme that requires only entry of the wedge angle and fixed jaw value. Filters for computerized treatment planning were configured for each wedge angle. We also examined to what degree the multileaf collimation (MLC) orientation, which is orthogonal to the EDW direction, was compromised for specific treatment sites. As a comparative test, we examined the dosimetric consistency for the 8 sets of physical wedges on the four machines. Finally, we updated our DW quality assurance program for EDW. RESULTS The measured EDW WF was common for all four machines to within +/- 1.5% and the calculation scheme held to within 1.5%. The EDW isodoses were consistent among the machines as measured by film and diode array. The treatment-planning filters provided computed isodose profiles that were nearly identical to measured profiles. Regarding MLC orientation, we found that the collimator angle needed for EDW did not compromise isodose distributions, as apparent in measured isodoses and calculated dose-volume histograms. The consistency of the physical wedges did not fare as well. Two of the lower wedge sets had Wfs and profiles different (> 3%) from the other wedge sets. CONCLUSIONS We have successfully implemented EDW on four machines using only one WF table and one set of treatment-planning filters. The EDW provides for improved treatment techniques for particular sites due to the large field sizes and additional angles available. Daily treatment efficiency has increased because of the remote capability provided by EDW.
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
January 1997,
Medical dosimetry : official journal of the American Association of Medical Dosimetrists,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
January 2000,
Medical dosimetry : official journal of the American Association of Medical Dosimetrists,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
February 1999,
Physics in medicine and biology,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
January 1997,
Medical dosimetry : official journal of the American Association of Medical Dosimetrists,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
April 2009,
Journal of applied clinical medical physics,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
January 1997,
Medical dosimetry : official journal of the American Association of Medical Dosimetrists,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
February 1995,
International journal of radiation oncology, biology, physics,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
June 2013,
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB),
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
January 2000,
Medical dosimetry : official journal of the American Association of Medical Dosimetrists,
E E Klein, and
R Gerber, and
X R Zhu, and
F Oehmke, and
J A Purdy
March 2005,
Australasian physical & engineering sciences in medicine,
