Intraoperative Ultrasound Calibration for Prostate Cancer Brachytherapy
Prostate cancer is the second most common cancer in North American men. Brachytherapy, applied in about 55,000 cases annually in North America, entails the permanent implantation of radioactive sources into the prostate, under real-time ultrasound image guidance. Brachytherapy systems require careful calibration to ensure the correct spatial relationship between the implant needles and the ultrasound image. Incorrect calibration leads to faulty delivery of the radiation dose, which, reducing the efficacy of cancer control and directly contributing to negative side effects like rectal ulcers and incontinence. Calibration today is a costly, laborious and manual process, involving a great deal of subjective judgment by the operator. It is performed periodically, outside the operating room, with the assumption that calibration parameters remain valid over time. In reality, however, calibration parameters change during storage, transportation and setup of the equipment. Calibration errors are virtually impossible to detect during the procedure so the surgeon can never be certain whether the system is functioning correctly. To improve contemporary practice, we calibrate the system in the operating room while the patient is being prepared for surgery. Our method is fast, fully automated and based on computations alone, eliminating subjectivity and human error. In this proposed research, we will create a fully functional brachytherapy calibration system, field test it, and bring it to readiness for commercial distribution. The resulting product will simultaneously reduce treatment costs, increase safety and improve on the accuracy of prostate cancer brachytherapy. The commercial partner for this is Precision Therapeutics Inc. (PTI), a medical device company based in Kingston, Ontario. PTI develops ultrasound image guided systems for the diagnosis and treatment of prostate cancer. Through established strategic alliances, PTI has direct access to the prostate brachytherapy market in North America and worldwide. PTI owns, licenses or has access to all of the pieces of the proposed intellectual property portfolio, to operate freely and market the iCal products.
