Systems and methods for real time tracking of targets in radiation therapy and other medical applications

Abstract

Systems and methods for tracking targets in real time for radiation therapy and other applications. In one embodiment, a method includes collecting position information of a marker implanted within a patient at a site relative to the target at a time tn, and providing an objective output indicative of the location of the target based on the position information collected at time tn. The objective output is provided to a memory device, user interface, and / or radiation delivery machine within 1 ms to 2 seconds of the time tn when the position information was collected. This embodiment of the method can further include providing the objective output at a periodicity of 10-200 ms during at least a portion of a treatment procedure. For example, the method can further include generating a beam of ionizing radiation and directing the beam to a machine isocenter, and continuously repeating the collecting procedure and the providing procedure every 10-200 ms while irradiating the patient with the ionizing radiation beam.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims the benefit of U.S. Provisional Application No. 60 / 610,509 filed on Sep. 16, 2004, and U.S. Provisional Application No. 60 / 590,894 filed on Jul. 23, 2004, both of which are incorporated herein by reference in their entireties.TECHNICAL FIELD [0002] This invention relates generally to radiation therapy systems, and more particularly to systems and methods for accurately locating and tracking a target in real time for guiding and assessing radiation therapy. The invention, however, is also useful in other medical applications. BACKGROUND OF THE INVENTION [0003] Radiation therapy has become a significant and highly successful process for treating prostate cancer, lung cancer, brain cancer and many other types of localized cancers. Radiation therapy procedures generally involve (a) planning processes to determine the parameters of the radiation (e.g., dose, shape, etc.), (b) patient setup processes to position...

AI Technical Summary

Problems solved by technology

Increasing the radiation dose, however, also increases the potential for complications to healthy tissues.

One difficulty of radiation therapy is that the target often moves within the patient either during or between radiation sessions.

This is not a desirable solution because the larger treatment margins may irradiate a larger volume of normal tissue.

Another challenge in radiation therapy is accurately aligning the tumor with the radiation beam.

Conventional setup procedures using external marks are generally inadequate because the target may move relative to the external marks between the patient planning procedure and the treatment session and / or during the treatment session.

Moreover, if the target moves during treatment because of respiration, organ filling, or cardiac conditions, any initial misalignment will likely further exacerbate irradiation of normal tissue.

Thus, the day-by-day and moment-by-moment changes in target motion have posed significant challenges for increasing the radiation dose applied to patients.

This requirement renders these systems useless for implanted markers or markers that are otherwise in the patient (i.e., out of the line-of-sight of the detector and / or the light source).

Thus, conventional optical tracking systems have many restrictions that limit their utility in medical applications.

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