Planning system, method and apparatus for conformal radiation therapy

Abstract

A system and associated methods to determine an optimal radiation beam arrangement are provided. The system includes a computer planning apparatus which includes a treatment plan optimization computer having a memory and an input device in communication with the treatment plan optimization computer to provide user access to control functions of plan optimization software. An image gathering device is in communication with the treatment plan optimization computer through a communications network to provide an image slice of the tumor target volume and the non-target structure volume. The plan optimization software computationally obtains and then optimizes a proposed radiation beam arrangement iteratively based on constraints to form an optimized radiation beam arrangement. A conformal radiation therapy delivery device in communication with the treatment plan optimization computer through the communications network then applies the optimized radiation beam arrangement to the patient.

Description

RELATED APPLICATIONS [0001]This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 60 / 518,020, filed Oct. 7, 2003, titled “Planning System, Method, and Apparatus for Conformal Radiation Therapy,” which is incorporated by reference in its entirety, and this application is a divisional application of U.S. application Ser. No. 10 / 960,424 filed on Oct. 7, 2004.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates generally to radiation therapy, and more specifically to conformal radiation therapy of tumors, and particularly to a radiation therapy treatment planning system, methods, and apparatus for conformal radiation therapy.[0004]2. Description of Related Art[0005]Modern day radiation therapy of tumors has two goals: eradication of the tumor, and avoidance of damage to healthy tissue and organs present near the tumor. It is known that a vast majority of tumors can be eradicated completely if a suffic...

AI Technical Summary

Benefits of technology

[0037]In view of the foregoing, embodiments of the present invention advantageously provide a system to determine an optimal radiation beam arrangement for applying radiation to a tumor target volume while minimizing radiation of a non-target structure volume in a patient. Advantageously, embodiments of the present invention provide a computer planning apparatus that can display immediately a user's request simultaneously with that which the planning system can achieve, and can permit the user to dynamically edit goals and change terms in which the user would specify a prescription. Advantageously, embodiments of the present invention provide for a real-time, direct manipulation of isodose contour lines on an isodose plot on a tomographic scan and direct manipulation of dosimetric statistics, utilizing an input device, and provide the user the ability to adjust individual constraints, preferably one constraint at a time, which in turn causes adjustment to both the isodose contours and the dosimetric statistics.

[0038]Advantageously, embodiments of the present invention provide plan matching of an arbitrary / external precedent radiation treatment plan by constructing an optimization objective function having extremum corresponding to the radiation beam configuration of the precedent plan. Advantageously, embodiments of the present invention include a computer planning apparatus that can provide dynamic constraint balancing, i.e., a real-time system for adjusting dosimetric goals while viewing at least one representation of dose in the patient, and automatic constraint weighing, i.e., a level of interactivity that in turn permits the prioritization to be inferred from user actions and a sequence of user inputs in the form of plan adjustments rather than direct entry of such priorities. Advantageously, embodiments of the present invention provide the user with a real-time control permitting the user to dynamically undo a change, completely or partially, and to explore trade-offs between treatment plans, in order to quickly select an optimum balance between versions of a treatment plan and between treatment plans developed on different systems. Advantageously, embodiments of the present invention provide software including an algorithm for automatic selection of minimal plan evaluation points. Advantageously, embodiments of the present invention provide software for converting an optimized plan into a deliverable discrete one.

Problems solved by technology

It is known that a vast majority of tumors can be eradicated completely if a sufficient radiation dose is delivered to the tumor volume; however, complications may result from use of the necessary effective radiation dose, due to damage to healthy tissue which surrounds the tumor, or to other healthy body organs located close to the tumor.

A major problem associated with such prior art methods of conformal radiation therapy are that if the tumor volume has concave borders, or surfaces, varying the spatial configuration, or contour, of the radiation beam, is only successful part of the time.

Such dedicated scanning beam therapy machines, which utilize direct beam energy modulation, are expensive and quite time consuming in their use and operation, and are believed to have associated with them a significant patient liability due to concerns over the computer control of the treatment beam.

However, the cost functions used in existing methods generally do not account for the structure volumes as a whole, relying merely on costs related to discrete points within the structure, and further, generally do not account for the relative importance of varying surrounding structure types.

Existing cost functions utilized in the optimization of treatment plans traditionally have not accounted for such varying costs associated with the different types of structures.

Further, existing methods and apparatus traditionally have not allowed the physician to utilize the familiar partial volume data associated with Cumulative Dose Volume Histogram (“CDVH”) or dose volume histograms (“DVH”) curves in establishing the desired dose distributions.

This process can be time-consuming.

The DVH curves, representing the volumetric statistics of a plan processed by a computer, however, are not manipulatable.

Many current treatment planning systems require the user to explicitly prioritize goals, which may be a difficult, imprecise, and potentially time-consuming process.

This task is virtually physically impossible.

Developing such priorities may be a difficult and time-consuming task for the treatment planner.

The user may then realize the consequences of that prioritization and may back off on its importance by partially undoing it.

These constraints limit the treatment plans that the user can develop.

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