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JP-7856664-B2 - Optimization of thermal radiation therapy

JP7856664B2JP 7856664 B2JP7856664 B2JP 7856664B2JP-7856664-B2

Inventors

  • トラネウス，エリック
  • オデン，ヤコブ
  • エリクソン，シェル
  • フレドリクソン，アルビン

Assignees

  • レイサーチ ラボラトリーズ エービー

Dates

Publication Date
20260511
Application Date
20220413
Priority Date
20210427

Claims (15)

  1. A computer-based method for generating a set of treatment plans, including a radiotherapy plan and a hyperthermia treatment plan for a patient's treatment volume, a. A step of obtaining an optimization problem including at least one objective function relating to multimodality therapy including hyperthermia therapy and radiotherapy, wherein the optimization problem includes at least one constraint relating to limitations on at least one radiotherapy supply device and at least one hyperthermia therapy supply device, and the objective function is a function of the combined biological effect of temperature and dose for each voxel of a plurality of voxels of the therapy volume, using a biophysical model having temperature-dependent parameters. b. A step of generating at least one of the radiotherapy plan and the hyperthermia treatment plan by optimizing the value of the objective function that evaluates the combined biological effects on the set of treatment plans, Methods that include...
  2. The method according to claim 1, wherein the radiotherapy plan is an external beam radiotherapy plan.
  3. The method according to claim 1 or 2, wherein the step of generating at least one of the radiotherapy plan and the hyperthermia treatment plan includes co-optimization of the hyperthermia treatment plan and the radiotherapy plan .
  4. The method according to claim 1 or 2, wherein, prior to the step of obtaining the optimization problem, an existing hyperthermia treatment plan is obtained, and the step of generating the radiotherapy plan and at least one of the hyperthermia treatment plans includes optimizing the radiotherapy plan to compensate for the combined biological effects of at least one existing hyperthermia treatment plan.
  5. The method according to claim 1 or 2, wherein an existing radiotherapy plan is obtained, and the step of generating at least one of the radiotherapy plan and the hyperthermia plan comprises optimizing the hyperthermia plan to compensate for the combined biological effects of at least one existing radiotherapy plan.
  6. The method according to claim 1, wherein the biophysical model comprises one or more of the following: equivalent dose-weighted dose (EQD), equivalent uniform distribution (EUD), biologically effective dose (BED), thermal sensitization ratio (TER), tumor control rate (TCP), normal tissue damage rate (NTP), possibility of cure without complications, secondary cancer, and/or overall survival.
  7. The method according to claim 1, wherein the optimization problem includes constraints defining parameters to be maintained during the optimization.
  8. The method according to claim 1, further comprising the optimization problem for a physical purpose.
  9. The method according to claim 1, wherein the optimization problem is defined to optimize at least one mechanical parameter of the heat supply system and the radiation supply system as a variable.
  10. The method according to claim 1, wherein the optimization problem includes a simplified mechanical model for either the heat supply system or the radiation supply system , in which parameters such as radiation effects optimization and power optimization for the heat supply system are optimized.
  11. The method according to claim 1, further comprising a step performed prior to the step of claim 1, which defines a set of treatment plans, including the hyperthermia treatment plan and the radiotherapy plan, and at least one other type of plan, such as surgery or a plan for a certain type of systemic treatment, including chemotherapy, immunotherapy, and hormone therapy.
  12. The method according to claim 1, wherein the set of treatment plans comprises at least first and second radiotherapy plans , the first radiotherapy plan being optimized for supply on the same day as at least one of the hyperthermia treatment plans, and the second radiotherapy plan being optimized for supply on days when no hyperthermia treatment plan is supplied.
  13. The method according to claim 1, wherein the set of treatment plans comprises at least one additional therapy plan, as well as at least one hyperthermia therapy plan and at least one radiotherapy plan , the at least one additional therapy plan relating to a systemic treatment such as chemotherapy.
  14. A computer program product comprising computer-readable code means for causing the processor to execute the method described in claim 1 when executed within the processor.
  15. A computer comprising a processor and program memory, wherein the program memory holds the computer program product described in claim 14 for execution within the processor.

Description

[001] The present invention relates to a multimodality therapy plan that combines radiotherapy and hyperthermia therapy. Such therapies are often referred to as hyperthermic radiotherapy or hyperthermic intensified radiotherapy. [002] Radiotherapy (or radiation therapy: RT) involves exposing a patient's body to radiation. Hyperthermia (HT) refers to the treatment of malignant diseases by heating tissue. Various heating techniques can be used, including but not limited to liquid agents, dielectric heating systems, exposure to electromagnetic radiation (radio frequency, microwave, or infrared), and sound waves (ultrasound). The use of HT also enhances the effects of several systemic types of therapy, such as RT and chemotherapy. Raising tumor temperature to approximately 39–45°C in combination with RT and/or systemic therapy has been shown to increase tumor control rates (TCP) and virtually no increase in recent normal tissue injury rates (NTCP) compared to single-modality therapy. This synergistic effect is attributed to various sensitizing effects of HT, including the suppression of DNA repair mechanisms and reoxygenation, as well as direct HT cell death of radiation-resistant hypoxic tumor cells and the induction of multiple immune responses. The radiation sensitization effect can be mathematically quantified using known concepts such as equivalent radiation dose (EQD) including temperature-dependent parameters for radiation, biological models including TCP and NTCP that can depend on temperature-dependent EQD, and the thermal sensitization ratio (TER), defined as the ratio of the radiation dose required to produce a specific therapeutic effect without HT therapy to the radiation dose required to produce the same therapeutic effect in combination with HT therapy. [003] Typically, different devices are used for HT therapy and RT therapy, and therefore, for practical reasons, they are usually administered to the patient consecutively with treatment intervals of approximately 0 to 4 hours. The supply of different treatment modalities can also be simultaneous. RTHT therapy typically consists of approximately 5 to 35 RT portions supplied daily, with 1 to 2 HT boosts per week, resulting in a total of approximately 1 to 10 HT portions. Generally, strategies exist for adapting the RT plan to the HT supply schedule, but the same RT therapy is supplied regardless of whether the HT portions are supplied on the same day. [004] This multimodality optimization involves the optimization of at least one RT plan and at least one HT plan. [005] The general goal of all such therapies is to optimize the therapeutic effect on the patient. In the case of multimodality therapy, this involves utilizing as many synergistic effects as possible. In the case of RTHT therapy, this involves utilizing the effects of co-localization of high-temperature or low-temperature voxels, along with the RT dose, to compensate for temperature-dependent radiosensitization in each voxel. [006] Accordingly, International Patent Application PCT/EP2016/074609 discloses a method for planning hyperthermia-enhanced radiotherapy, in which a plan relating to either hyperthermia therapy or radiotherapy is first developed. After this plan is supplied to the patient, the results are evaluated and taken into consideration when optimizing other plans. In other words, the hyperthermia treatment plan is optimized and supplied, and the radiotherapy plan is optimized taking into consideration the results of the supply, or vice versa. [007] The object of this disclosure is to provide an improved planning method for multimodality therapy involving both radiotherapy and hyperthermia. This flowchart shows different embodiments of the method according to the present invention.This flowchart shows different embodiments of the method according to the present invention.This flowchart shows different embodiments of the method according to the present invention.This is a schematic diagram showing a computer system capable of performing the method. [022] Methods according to embodiments of the present invention relate to the optimization of treatment plans. As is known in the art, such optimization is performed by applying an optimization problem designed for the given situation based on clinical goals and one or more biological models. The optimization problem is defined by an objective function that defines the goal that the optimization should strive for, e.g., minimizing the dose to the tissue surrounding the target, and absolute conditions, e.g., constraints that make the minimum dose to the target known. The constraints may also reflect mechanical limitations of at least one supply machine that will be used to supply hyperthermia and/or radiotherapy. Those skilled in the art will be familiar with such constraints, including the maximum speed of machine components, the maximum radiation supply per unit of time, and other limitations. [023] Figure 1 is a flowchart detailing