WARF TECHNOLOGIES

Radiopharmaceuticals are radioactive materials that “target” specific tissues to allow imaging or treatment. During radiation therapy, the radiopharmaceutical must be administered to provide a radiation dose to the tissue sufficient to kill tumor cells while minimizing damage to surrounding healthy tissues. The measurement of the exposure of the tissue to the radiation is called dosimetry, which is related to the biokinetics of the radioisotope in tumor tissue and healthy organs. Selecting the appropriate quantity and timing for administration of a radiopharmaceutical may be approximated by using SPECT imaging, a “standard man” model or extrapolation from animal models, such as rodents to humans. However, these techniques do not provide estimations tailored to individual patients.

While 3-D treatment planning software exists for externally administered radiotherapy systems, developing 4-D planning software for systemically administered radiotherapy has been limited by a lack of precise dosimetry prescription. A method to provide more precise scientific dosimetry prescriptions is needed.

UW-Madison researchers have developed a system for precisely tailoring the quantity and timing of the administration of a radiopharmaceutical to a particular patient. To generate time-activity curves, an imaging radioisotope is first administered and the subject is scanned using dynamic PET/CT imaging. From the acquired datasets, the critical organ, which displays toxicity at the lowest injection level, is determined. A fractionation scheme is then developed for tumor control and toxicity avoidance, and precise, patient-specific administration schedules are created based on the effect that varying dose rates have on the critical organs and tumors. This two-step technique can provide sufficient precision to allow the combination of radiopharmaceutical treatment with other radiation treatment such as external-beam radiotherapy.

• Treatment planning for patients undergoing cancer treatment, including systemically administered radiation therapy
• Combined therapies with external radiation beams

• Provides patient-specific, tailored treatment schedules
• Models uptake and clearing time differences among tissues with accuracy
• Allows for further development of 4-D treatment planning software for systemically administered radiotherapy

For More Information About the Inventors

• Jamey Weichert
• Robert Jeraj

Tech Fields

• Information Technology : Computing methods, software & machine learning
• Radiation Therapy : Treatment planning