A single plan approach for differentially dosing sequential target volumes.
An in-house protocol for treatment of malignant astrocytomas requires development of a single treatment plan constructed to deliver different doses to three sequential target volumes. This single plan approach fundamentally differs from a previous protocol in which these sequential volumes were approached with three consecutive treatment plans, each tailored to a separate target, with the final target receiving a cumulative dose of 80 Gy. The intent of the revised protocol is to deliver doses to the two larger targets that are biologically equivalent (using the linear quadratic model) to the cumulative doses received by these targets in the earlier protocol, while escalating the final target dose to 90 Gy. This requires the treatment planner to manipulate the conformation of three different isodose levels simultaneously to produce a treatment plan fulfilling all protocol specifications. This paper will focus on the evolution of design for the current technique used to clinically implement this protocol.
Marsh
L H
LH
University of Michigan Hospital, Department of Radiation Oncology, Ann Arbor 48109, USA.
Ten Haken
R K
RK
Sandler
H M
HM
D001254:Astrocytoma / Q000532:radiotherapy*; D001932:Brain Neoplasms / Q000532:radiotherapy*; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted