Planning method and apparatus for radiation dosimetry

A method of determining an optimized radiation beam arrangement for applying radiation to a tumor target volume while minimizing radiation of a structure volume in a patient, comprising the steps of:

• (a) determining a desired CDVH associated with each target and structure;
• (b) using a computer to iteratively compare a cost of a radiation beam arrangement proposed during a given iteration to a radiation beam arrangement proposed during the previous iteration based on the relative costs associated with the proposed radiation beam arrangement, the costs being calculated by:
• (1) determining a CDVH associated with each target and structure based on the proposed radiation beam arrangement of a given iteration;
• (2) assigning cost zones to the desired CDVH and the proposed CDVH of a given iteration associated with each target and structure;
• (3) assigning a weight value to each cost zone of each CDVH associated with each target and structure;
• (4) for each target and structure, multiplying the weight value of each zone by the quotient of a value representing the area of the zone of the CDVH associated with the proposed radiation beam arrangement and a value representing the area of the zone of the CDVH associated with the desired radiation beam arrangement;
• (5) summing the results of step (4) for each zone of each CDVH of each target and structure to obtain a total dosage cost;
• (c) increasing or decreasing radiation beam intensity if the change of the proposed beam arrangement leads to a greater correspondence to the desired dose prescription;
• (d) allowing a radiation limit on the tissue structure to be exceeded by a set amount if such excess allows better conformation to the desired target CDVH curve;
• and
• (e) repeating steps b through d until the proposed radiation beam arrangement has obtained an optimized radiation beam arrangement.

A method of determining an optimized radiation beam arrangement for applying radiation to a tumor target volume while minimizing radiation of a structure volume in a patient, comprising the steps of:

• using a computer to iteratively obtain a proposed radiation beam arrangement;
• providing a user with a selective range of input values with an indication of the importance of the value in providing an optimized radiation beam arrangement;
• and
• providing separate parameter profiles depending on the the user's input value selection.

Apparatus for determining an optimized radiation beam arrangement for applying radiation to a tumor target volume while minimizing radiation of a structure volume in a patient, comprising a computer which is adapted to:

• (a) computationally obtain a proposed radiation beam arrangement,
• (b) computationally change the proposed radiation beam arrangement iteratively to conform to a target CDVH curve,
• (c) incorporate a cost function at each iteration to approach correspondence of partial volume data associated with the proposed radiation beam arrangement to partial volume data associated with a predetermined desired dose prescription,
• (d) reject the change of the proposed radiation beam arrangement if the change of the proposed radiation beam arrangement leads to a lesser correspondence to the desired dose prescription and to accept the change of the proposed radiation beam arrangement if the change of the proposed radiation beam arrangement leads to a greater correspondence to the desired dose prescription to obtain an optimized radiation beam arrangement, and
• (e) exceed the cost function by a set amount if such excess allows better conformation with the target CDHV curve.

Apparatus for determining an optimized radiation beam arrangement for applying radiation to a tumor target volume while minimizing radiation of a structure volume in a patient, comprising a computer, including:

• means for computationally obtaining a proposed radiation beam arrangement;
• means for computationally changing the proposed radiation beam arrangement iteratively to conform to a CDHV curve;
• means for incorporating a cost function at each iteration to approach correspondence of partial volume data associated with the proposed radiation beam arrangement to partial volume data associated with a predetermined desired dose prescription;
• means for rejecting the change of the proposed radiation beam arrangement if the change of the proposed radiation beam arrangement leads to a lesser correspondence to the desired dose prescription and accepting the change of the proposed radiation beam arrangement if the change of the proposed radiation beam arrangement leads to a greater correspondence to the desired dose prescription to obtain an optimized radiation beam arrangement;
• and
• means for adapting the radiation beam arrangement to exceed the cost function by a set amount if such excess allows better conformation with the target CDHV curve.

A method of determining an optimized radiation beam arrangement for applying radiation to at least one tumor target volume while minimizing radiation of at least one structure volume in a patient, comprising the steps of:

• determining desired partial volume data for each of the at least one target volume and structure volume associated with a desired dose prescription;
• entering the desired partial volume data into a computer;
• in response to the desired partial volume data, using the computer to computationally approximate desired CDVHs for each of the at least one target and structure associated with the desired dose prescription;
• and
• using the computer to computationally calculate the optimized radiation beam arrangement associated with the CDVHs approximated by the computer.

A method of determining an optimized radiation beam arrangement for applying radiation to at least one tumor target volume while minimizing radiation to at least one structure volume in a patient, comprising the steps of:

• distinguishing each of the at least one tumor target volume and each of the at least one structure volume by target or structure type;
• determining desired partial volume data for each of the at least one target volume and structure volume associated with a desired dose prescription;
• entering the desired partial volume data into a computer;
• providing a user with a range of values to indicate the importance of objects to be irradiated;
• providing the user with a range of conformality control factors;
• and
• using the computer to computationally calculate an optimized radiation beam arrangement.