Trial Information

Phase I/II Evaluation of Cancer-Specific Imaging Using Ultrasound Spectrum Analysis (USA) to Guide Dose Escalated Prostate Brachytherapy

Prostate brachytherapy is an increasingly popular treatment for clinically localized
prostate cancer.In properly selected patients, it is highly effective with biochemical (PSA)
disease free survival rates of 80-87% at 5-10 years.However, the technique is currently
limited by the inability to localize the cancer within the prostate. The multifocal nature
of prostate cancer is well established. Because of the inability to know where within the
prostate the cancer is located, radiation must be delivered throughout the gland. Although
this blind approach leads to good results, it is clear that there are regions of the
prostate and surrounding tissue that are overexposed to radiation while others are
underexposed relative to their true need based on their tumor burden and their proximity to
the tumor areas.Feleppa et al. at Riverside Research Institute (New York, NY), a non-profit
ultrasound research center, have developed an ultrasound-based technique to identify
cancer-containing areas within the prostate. This technique uses current ultrasound
equipment already in use for prostate brachytherapy guidance. By extracting and processing
the radiofrequency signal obtained from the ultrasound transducer in ways not done to create
the standard B-mode ultrasound image, areas of cancer can be identified and displayed
overlying the standard B-mode ultrasound image.In this study, we propose to obtain these
ultrasound-based cancer-specific images of the prostate prior to the brachytherapy and use
them to direct the dosimetry planning.The primary goal of this study is to demonstrate that
this imaging modality can be incorporated into the treatment planning process for
brachytherapy. Furthermore, we wish to demonstrate the improved dosimetry of the
cancer-identified regions while maintaining the urethral dose guidelines noted above. We
also wish to compare the differences in dose to the other adjacent normal structures
(anterior rectum and right and left neurovascular bundles). Additionally, we seek to
demonstrate, at a minimum, no increased toxicity with this approach and similar disease
control rates. Of course, ultimately the goal will be to demonstrate a superior therapeutic
ratio with this technique.