Interactive dose manipulation using prioritized constraints

Patent metadata

Field	Value
Publication number	US-2020009401-A1
Application number	US-201916563618-A
Country	US
Kind code	A1
Filing date	Sep 6, 2019
Priority date	Dec 30, 2016
Publication date	Jan 9, 2020
Grant date	—

Abstract

In a method of interactive manipulation of the dose distribution of a radiation treatment plan, after an initial candidate treatment plan has been obtained, a set of clinical goals are transferred into a set of constraints. Each constraint may be expressed in terms of a threshold value for a respective quality index of the dose distribution. The dose distribution can then be modified interactively by modifying the threshold values for the set of constraints. Re-optimization may be performed based on the modified threshold values. A user may assign relative priorities among the set of constraints. When a certain constraint is modified, a re-optimized treatment plan may not violate those constraints that have priorities that are higher than that of the modified constraint, but may violate those constraints that have priorities that are lower than that of the modified constraint.

First claim

What is claimed is:

1 . A computer product comprising a non-transitory computer readable medium storing a plurality of instructions that when executed control a computer system to allow interactive manipulation of dose distribution of a radiation treatment plan using an external-beam radiation treatment system, the instructions comprising:
obtaining, by the computer system, an initial radiation treatment plan, the initial radiation treatment plan producing an initial dose distribution that satisfies a plurality of clinical goals, wherein the plurality of clinical goals are expressed in terms of a plurality of initial threshold values for a plurality of quality indexes, each respective quality index relating to a respective statistical quantity of the initial dose distribution; converting, by the computer system, the plurality of clinical goals into a plurality of constraints relating to the plurality of quality indexes, each constraint having a respective initial reference value corresponding to the initial threshold value of the respective quality index, each respective constraint having a corresponding priority indicating relative importance of the respective constraint among the plurality of constraints; providing a user interface to a user, the user interface allowing the user to change an initial reference value to a new reference value for one of the plurality of constraints; and performing, by the computer system, re-optimization of the initial radiation treatment plan to obtain an updated radiation treatment plan using the new reference value for the one of the plurality of constraints, the updated radiation treatment plan producing an updated dose distribution, wherein the re-optimization enforces the updated dose distribution to satisfy any constraint that has a priority higher than a priority of the one of the plurality of constraints while allowing any constraint that has a priority lower than the priority of the one of the plurality of constraints to be violated.

2 . The computer product of claim 1 , wherein the updated radiation treatment plan includes a control-point sequence and a multileaf collimator (MLC) leaf sequence to be used by the external-beam radiation treatment system for delivering radiation to a patient.

3 . The computer product of claim 2 , wherein the instructions further comprise:
transmitting the updated radiation treatment plan to control circuitry of the external-beam radiation treatment system to cause the external-beam radiation treatment system to deliver the radiation to the patient according to the control-point sequence and the multileaf collimator (MLC) leaf sequence of the updated radiation treatment plan.

4 . The computer product of claim 1 , wherein the updated dose distribution satisfies the one of the plurality of constraints having the new reference value.

5 . The computer product of claim 1 , wherein the updated dose distribution minimizes an amount of violation of each constraint that is violated.

6 . The computer product of claim 5 , wherein the updated dose distribution corresponds to an achieved reference value for each constraint that is violated, and the instructions further comprise replacing the initial reference value of each constraint that is violated with the achieved reference value.

7 . The computer product of claim 1 , wherein another one of the plurality of constraints has a same priority as the one of the plurality of constraints, and wherein the updated dose distribution satisfies the another one of the plurality of constraints.

8 . The computer product of claim 1 , wherein another one of the plurality of constraints has a same priority as the one of the plurality of constraints, and wherein the updated dose distribution is allowed to violate the another one of the plurality of constraints.

9 . The computer product of claim 1 , wherein the instructions further comprise:
allowing the user to, at the user interface, create a new constraint corresponding to a new quality index; and performing, by the computer system, re-optimization of the updated radiation treatment plan to obtain a second updated radiation treatment plan using the new constraint.

10 . The computer product of claim 1 , wherein the instructions further comprise:
allowing the user to, at the user interface, change priorities of one or more of the plurality of constraints; and performing, by the computer system, re-optimization of the updated radiation treatment plan to obtain a second updated radiation treatment plan, the second updated radiation treatment plan produces a second updated dose distribution that satisfies as many constraints of higher priorities as possible.

11 . A computer product comprising a non-transitory computer readable medium storing a plurality of instructions that when executed control a computer system to determine a radiation treatment plan for delivering radiation to a patient using an external-beam radiation treatment system, the instructions comprising:
receiving, via a user interface of the computer system, a first clinical goal and a second clinical goal, wherein the first clinical goal includes a first acceptable threshold value and a first desired threshold value for a first quality index relating to a first statistical quantity of a dose distribution, and the second clinical goal includes a second acceptable threshold value and a second desired threshold value for a second quality index relating to a second statistical quantity of the dose distribution; obtaining, by the computer system, a cost function including a first term with a first weight and a second term with a second weight, wherein the first term is proportional to a value of the first quality index in excess of the first acceptable threshold value, and the second term is proportional to a value of the second quality index in excess of the second acceptable threshold value, and wherein the first weight is inversely proportional to a difference between the first desired threshold value and the first acceptable threshold value, and the second weight is inversely proportional to a difference between the second desired threshold value and the second acceptable threshold value; and performing, by the computer system, optimization using the cost function to obtain an optimal radiation treatment plan having an optimal value for the cost function.

12 . The computer product of claim 11 , wherein the optimal radiation treatment plan includes a control-point sequence and a multileaf collimator (MLC) leaf sequence to be used by the external-beam radiation treatment system for delivering radiation to a patient.

13 . The computer product of claim 12 , wherein the instructions further comprise:
transmitting the optimal radiation treatment plan to control circuitry of the external-beam radiation treatment system to cause the external-beam radiation treatment system to deliver the radiation to the patient according to the control-point sequence and the multileaf collimator (MLC) leaf sequence of the optimal radiation treatment plan.

14 . The computer product of claim 11 , wherein the first term of the cost function is proportional to square of the value of the first quality index in excess of the first acceptable threshold value, and the second term is proportional to square of the value of the second quality index in excess of the second acceptable threshold value.

15 . The computer product of claim 14 , wherein the first weight is inversely proportional to square of the difference between the first desired threshold value and the first acceptable threshold value, and the second

Assignees

• Varian Medical Systems Int Ag

Inventors

• Kuusela Esa
• Siket-Szasz Edit
• Lessard Marco
• Halko Lauri

Classifications

• A61N5/1031 Primary

  using a specific method of dose optimization · CPC title

• A61N5/1038

  taking into account previously administered plans applied to the same patient, i.e. adaptive radiotherapy · CPC title

• A61N5/103 Primary

  Treatment planning systems · CPC title

• A61N5/1077

  Beam delivery systems · CPC title

• G21K1/025

  using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation · CPC title