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Sci—Thur PM: Planning & Delivery — 06: Real‐Time Interactive Treatment Planning
Author(s) -
Matthews Q,
Mestrovic A,
Otto K
Publication year - 2014
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4894986
Subject(s) - radiation treatment planning , nuclear medicine , dosimetry , head and neck , computer science , dose rate , radiation therapy , medicine , medical physics , radiology , surgery
Purpose: To describe and evaluate a novel system for generalized Real‐Time Interactive Planning (RTIP) applied to head & neck (H&N) VMAT. Methods: The clinician interactively manipulates dose distributions using DVHs, isodoses, or rate of dose fall‐off, which may be subjected to user‐defined constraints. Dose is calculated using a fast Achievable Dose Estimate (ADE) algorithm, which simulates the limits of what can be achieved during treatment. After each manipulation contributing fluence elements are modified and the dose distribution updates in effectively real‐time. For H&N VMAT planning, structure sets for 11 patients were imported into RTIP. Each dose distribution was interactively modified to minimize OAR dose while constraining target DVHs. The resulting RTIP DVHs were transferred to the Eclipse™ VMAT optimizer, and conventional VMAT optimization was performed. Results: Dose calculation and update times for the ADE algorithm ranged from 2.4 to 22.6 milliseconds, thus facilitating effectively real‐time manipulation of dose distributions. For each of the 11 H&N VMAT cases, the RTIP process took ∼2–10 minutes. All RTIP plans exhibited acceptable PTV coverage, mean dose, and max dose. 10 of 11 RTIP plans achieved substantially improved sparing of one or more OARs without compromising dose to targets or other OARs. Importantly, 10 of the 11 RTIP plans required only one or two post‐RTIP optimizations. Conclusions: RTIP is a novel system for manipulating and updating achievable dose distributions in real‐time. H&N VMAT plans generated using RTIP demonstrate improved OAR sparing and planning efficiency. Disclosures: One author has a commercial interest in the presented materials.