Intraoperative dosimetry for prostate brachytherapy using transrectal ultrasound and x-ray fluoroscopy

A system for performing a prostate brachytherapy procedure on a patient, in which radioactive seeds are implanted at a treatment site in the patient, and for intraoperatively determining a dosage parameter for implanted seeds during the procedure, comprising:

• (a) an ultrasound system that includes a probe configured to produce ultrasound data corresponding to volumetric images of the treatment site, or to both axial and longitudinal ultrasound images of the treatment site, the longitudinal images being generally aligned with a longitudinal axis of seeds that have been implanted and the axial images being generally transverse to the longitudinal axis of the seeds that have been implanted, the ultrasound data being capable of indicating locations of a minority of the seeds that have been implanted relative to the prostate of the patient;
• (b) a fluoroscope that is configured for producing X-ray data for the treatment site, for indicating a majority of the seeds that have been implanted;
• and
• (c) a computing device for processing the ultrasound data and the X-ray data, said computing device carrying out a plurality of functions, including:
• (i) processing the X-ray data to identify the majority of the implanted seeds;
• (ii) processing the ultrasound data to identify a location of the prostate, and to identify locations of each of the minority of the implanted seeds relative to the prostate;
• (iii) registering the majority of the implanted seeds acquired from the X-ray data with the locations of the minority of the implanted seeds acquired from the ultrasound data to determine locations of the majority of the implanted seeds relative to the prostate;
• and
• (iv) determining a dosage parameter for the implanted seeds based on the locations of the majority of the seeds relative to the prostate.

A method for identifying radioactive seeds implanted at a treatment site, by automated processing of ultrasound data collected for the treatment site, comprising the steps of:

• (a) identifying bright structures in the ultrasound data having a reflected ultrasound power level that is substantially greater than a background power level;
• (b) detecting whether the bright structures identified in the ultrasound data correspond to line structures;
• and
• (c) detecting each of the line structures that includes an adjacent mirror structure reflection, wherein the mirror structure reflection is characteristic of a specular reflection from a seed and thereby indicates that the line structure is likely an implanted seed, to identify a location of at least a portion of the seeds implanted at the treatment site.

A system for identifying radioactive seeds implanted at a treatment site, by automated processing of ultrasound data collected for the treatment site, comprising:

• (a) a processor that is adapted to receive ultrasound data collected for a treatment site at which radioactive seeds have been implanted, the ultrasound data being usable to produce longitudinal ultrasound images that are generally aligned with a longitudinal axis of implanted seeds;
• and
• (b) a memory in which machine instructions are stored for implementing a plurality of functions when executed by the processor, including:
• (i) identifying bright structures in the ultrasound data having a reflected ultrasound power level that is substantially greater than a background power level;
• (ii) detecting whether the bright structures identified in the ultrasound data correspond to line structures;
• and
• (iii) determining whether any of the line structures detected includes an adjacent mirror structure reflection, wherein the adjacent mirror structure reflection is characteristic of specular reflection from a seed and thereby indicates that the line structure is likely an implanted seed, to identify locations of at least a portion of the seeds implanted at the treatment site.

A method for registering a subset of radioactive seeds implanted at a treatment site that have been identified in ultrasound data with a set of the radioactive seeds that have been identified in X-ray data, so that a spatial disposition of the set of seeds can be determined relative to a tissue portion of a patient's body, comprising the steps of:

• (a) providing the X-ray data and the ultrasound data as input to an optimization loop that transforms the X-ray data and correlates resulting transformed X-ray data with the ultrasound data;
• (b) iteratively entering the optimization loop until a predefined condition is met;
• and
• (c) once the predefined condition has been met, exiting the step of iteratively entering the optimization loop with a final pose parameter set that registers the X-ray data with the ultrasound data, such that when a cost associated with the final pose parameter set is a minimum, a disposition of each implanted seed relative to the tissue portion of the patient's body is defined by the final pose parameter set.

A system for registering a subset of radioactive seeds implanted at a treatment site that have been identified in ultrasound data with a set of the radioactive seeds that have been identified in X-ray data, so that a spatial disposition of the set of seeds can be determined relative to a tissue portion of a patient's body, comprising:

• (a) a processor that is adapted to receive both the ultrasound data and the X-ray data collected for the treatment site;
• and
• (b) a memory in which machine instructions are stored, for implementing a plurality of functions when executed by the processor, including:
• (i) executing an optimization loop that transforms the X-ray data and correlates resulting transformed X-ray data with the ultrasound data;
• (ii) iteratively entering the optimization loop until a predefined condition is met;
• and
• (iii) once the predefined condition has been met, providing a final pose parameter set that registers the X-ray data with the ultrasound data, such that when a cost associated with the final pose parameter set is a minimum, disposition of each implanted seed relative to the tissue portion of the patient's body is defined by the final pose parameter set.